2017 (All)

Question 1

3 Indications for ADA (ankle distraction arthroplasty)?

Answer 1

1. Young patient with PTA
2. Congruent joint
3. >20deg ROM

Question 2

How much is ankle joint contact area affected by as little as 1 mm talus displacement w/in mortise?

Answer 2

1-mm displacement of talus in the mortise = 42% less available joint contact area

Question 3

How much distraction with ADA is required?

Answer 3

5-mm of distraction is required to effectively unload the joint

Question 4

In ADA (ankle distraction arthroplasty), is there evidence for a hinged vs fixed fixator/frame?

Answer 4

No evidence to support a hinged fixator over a fixed one

Question 5

List 2 predictors of failure in ankle distraction arthroplasty

Answer 5

Predictors of failure:

1. Female
2. Poorer pre-op ROM

Question 6

List some contributing pathologies to be addressed at time of ankle distraction arthroplasty:

Answer 6

Address contributing pathology concurrently:

• supramalleolar osteotomy for extra-articular deformity,
• arthroscopic exostectomy for anterior osteophyte
• gastrocs recession

Question 7

What is the conversion rate to fusion for ADA?

Answer 7

44% at 12 years

Question 8

In ADA

1) how long does frame typically stay on for?
2) up to how long post frame removal will you see improvement?
3) does ROM improve/not-improve post frame removal

Answer 8

• Frame is removed after 8-12 weeks
• Improvements may occur 1-2 years after frame removal
• ROM doesn’t improve after frame removal

Question 9

What are the 4 broad categories of athletic hip injuries? What is the culprit lesion with each?

Answer 9

a) Adductor strains - Adductor longus usually the culprit
b) Osteitis pubis - Overuse of adductor tendons and rectus abdominis tendons attach on symphysis -

Chronic osteitis pubis shows lytic changes, sclerosis and widening of the symphysis

c) Athletic pubalgia (ie: “sports hernia”) - Abdominal wall tear, but no true hernia - Abdominal pain that radiates to the groin and perineum and ceases with rest
d) Intraarticular pathology

Question 10

List in decreasing order of incidence intra-articular hip injuries in pro-sports.

Answer 10

Intraarticular hip injuries: NHL > NFL > NBA

Extraarticular hip injures are highest in NBA

Question 11

List the five adductors:

Answer 11

adductor longus, brevis, magnus, gracilis, pectineus, obturator externus

Question 12

In which of the 2 categories of athletic hip injuries are corticosteroid injections useful? Timing?

Answer 12

Corticosteroid injections useful early in chronic adductor-related groin pain before enthesopathy develops as well as in acute osteitis pubis (within 2 weeks of diagnosis)

Question 13

Treatment for chronic recalcitrant chronic adductor enthesopathy?

Answer 13

Selective partial adductor release is an option

Question 14

Treatment for recalcitrant osteitis pubis?

Answer 14

symphysial debridement or fusion (level 5 evidence)

Question 15

What is athletic pubalgia?

Answer 15

Athletic pubalgia (ie: “sports hernia”) - Abdominal wall tear, but no true hernia - Abdominal pain that radiates to the groin and perineum and ceases with rest

Question 16

Which nerve should be decompressed when doing a repair for athletic pubalgia (sports hernia)?

Answer 16

Genital branch of genitofemoral nerve

Question 17

Post sports-hernia (athletic pubalgia) repair, what is return to sport protocol?

Answer 17

Patients undergoing minimal repair for athletic pubalgia can return to sport-specific training POD5 and play at 2 weeks

Question 18

What is the driving condition behind all 4 athletic hip conditions?

Answer 18

•Bottom line is all of these often coexist and are driven by FAI, which results in more stress on the symphysis, SI joints and lumbar spine to compensate for the loss of motion (think hockey goalie) – should address all issues of results aren’t as good

Question 19

What is the nervous supply to the labrum of the hip?

Answer 19

Labrum is innervated by branches of the obturator nerve and nerve to quadratus femoris

Labrum is also involved in proprioception (Pacini corpuscles)

Question 20

Does blood supply to labrum cross the chondro-labral junction?

Answer 20

NO, None of the blood supply to the labrum crosses the chondro-labral junction

Question 21

What is the rate of asymptomtaic labral tears in the general population?

Answer 21

69% rate of asymptomatic labral tears

Question 22

What physical exam sign is most strongly associated with labral pathology?

Answer 22

C-sign

Question 23

What is the classification system for labral tears?

Answer 23

Seldes classification of labral tears:

o Type I: chondrolabral junction

o Type II: intrasubstance tears

Question 24

in females, what is better, labral repair or debridement?

Answer 24

Krych RCT: repair > debridement in female patients with FAI

Question 25

What are Philipon’s (big name hip arthroscopist) poor prognostic factors in labral reconstruction (with autograft ITB) in irrepairable tears?

Answer 25

a) Age >30
b) <2-mm joint space

Question 26

Compare the collagen content and fiber orientation between the superior and inferior labrum

Answer 26

Anterosuperior labrum has lower collagen content and is parallel to the chondrolabral junction, as opposed to the posteroinferior labrum which has the highest collage content and is perpendicular note: Labrum increases the articular surface by 22% and volume by 33%; without it, femoroacetabular contact stresses increase up to 92%

Question 27

Benefit to arthroscopic vs open in labral tear repair?

Answer 27

Arthroscopic vs open = equivalent hip survival rates and patient-reported outcome measures

Question 28

Classify the 3 possible C.difficile infection categories in peri-operative care:

Answer 28

C. difficile infection classification:

o Community-acquired: <48h from admission

o Hospital-acquired: 48h-4 weeks

o >12 weeks following discharge: community-acquired

Note: NAP1 strain (25%) is hypervirulent – resistant to fluoroquinolones

Question 29

Risk factors for c.diff infections?

Answer 29

Risk factors:

-Age >65, diabetes, cancer, GI surgery, multiple antibiotic exposure (Clindamycin > Vancomycin), hospital exposure, feeding tube, revision surgery

Note:

• Fecal-oral transmission (possible too)
• Up to 50% rate of asymptomatic carriers in admitted patients

Question 30

List extra-GI complications of c.diff infection

Answer 30

Extra-GI complications: reactive arthritis, cellulitis, osteomyelitis, PJI

Question 31

What percent of patients with initial episodes of c.diff will have a recurrence?

Answer 31

Up to 40% of patients with an initial episode will have a recurrence

Question 32

Most common test for c.diff?

Answer 32

stool enzyme immunoassay looking for toxin A/B (sens 80%, spec 86%) — if positive, obtain stool culture

Question 33

Outline your treatment for c.diff infection (based on severity)

Answer 33

Treatment: treat until symptom resolution

o Mild: PO Metronidazole 500mg TID x 10-14 days

o Mod: PO Vancomycin 125mg QID x 10-14 days

o Severe: PO Vancomycin 500mg QID + IV Metronidazole 500mg TID o Severe with lactate >5 and WBC >50: subtotal colectomy

o Recurrence: don’t use Metronidazole (potential for cumulative neurotoxicity)

Question 34

Does c.diff infection in hip fracture patients affect their mortality rates?

Answer 34

YES Hip fracture patients that develop C. diff post-op have a 35% 6-month mortality (vs. 9% otherwise)

Question 35

DISTAL RADIUS FRACTURES IN THE ELDERLY What is superior, volar or dorsal plating?

Answer 35

Volar plating is associated with the following vs. dorsal plating:

o Improved function, grip strength and pain scores (first 6 months) and less risk of extensor irritation (dorsal plating = 30%)

Question 36

DISTAL RADIUS FRACTURES IN THE ELDERLY Most common surgical complication?

Answer 36

Most common surgical complication: infection

Question 37

DISTAL RADIUS FRACTURES IN THE ELDERLY Most common NON SURGICAL complication?

Answer 37

Most common NON SURGICAL complication: median neuropathy

Question 38

So surgery or not, for elderly DR fx?

Answer 38

Recent RCT comparing volar locked plating vs. non-op favored surgery for the first 6 months, but no difference after.

Question 39

Caucasian, female, osteoporotic patients with distal radius fractures, what can this do their fracture?

Answer 39

Increased risk of fracture displacement, malunion and late carpal malalignment in osteoporotic patients with distal radius fractures

Question 40

When can you expect pain, grip strength and ROM to improve post fracture?

Answer 40

Pain, grip strength and ROM may improve up to 4 years post-fracture

Question 41

What should you refer patient with DR fx to have?

Answer 41

Refer any patient with a distal radius fracture for BMD testing (FYI general guidelines are to perform BMD scan on women >65 and men >70)

Question 42

In complex distal radius fractures, what attaches to the radial column?

Answer 42

What attaches to the radial column?

o Brachioradialis

o Long radiolunate ligament

o Radioscaphocapitate ligament

Question 43

In complex distal radius fractures What attaches to the volar rim fragment?

Answer 43

What attaches to the volar rim fragment?

o Short radiolunate ligament

o Volar DRU ligament

Question 44

In complex distal radius fractures What attaches to the dorsal ulnar corner fragment?

Answer 44

What attaches to the dorsal ulnar corner fragment?

o Dorsal DRU ligament

Question 45

In complex distal radius fractures What attaches to the dorsal wall fragment? o Dorsal radiocarpal ligament

Answer 45

What attaches to the dorsal wall fragment?

o Dorsal radiocarpal ligament

Question 46

What x-ray view is volar rim fragment best seen in? (in complex distal radius fractures)

Answer 46

Volar rim fragment is seen on a standard lateral by measuring the teardrop angle (normal is 70deg)

Note: On a true lateral, a line along the volar cortex of the radial shaft passes through the center of the capitate

Question 47

PA or oblique view shows which fragment best? (in a complex distal radius fracture)

Answer 47

DUC fragment is seen on the PA or oblique view

Question 48

What are your Goals of ORIF in a complex distal radius fracture (5 goals)?

Answer 48

Goals of ORIF: o Radial shortening <5mm o Inclination >15deg o Step-off/gap <2mm o Sigmoid notch incongruity <2mm o Volar tilt 15-20deg Note: Fragment-specific fixation is useful when fragments are too small or too distal to be effectively captures with a volar locking plate

Question 49

Risk factors for CRPS in surgical management of distal radius fractures?

Answer 49

Excessive distraction through an ex-fix or dorsal bridge plate is a risk factor for CRPS

Question 50

What is BROADLY your order of fixation in a complex distal radius fracture?

Answer 50

1) Reduce intermediate column

(start with volar rim, DUC, FIA, then dorsal wall fragment)

2) Fix radial column (styloid)

3) Fix ulnar column (if DRUJ instability persists)

(DUC = dorsal ulnar corner, FIA = free intra-articular fragment)

Question 51

What is more SPECIFICALLY your order of fixation in on the intermediate column?

Answer 51

Reduce intermediate column to the pedestal (ulnar to radial)

1)Volar rim fragment (see first algorithm below)

Keep screws 75% of AP width of the distal radius – if you go too long, can prevent your reduction of 2)-4)

2) Dorsal ulnar corner (see second algorithm below)
3) Free intra-articular fragment
4) Dorsal wall fragment

Question 52

Your fixation algorithm on the radial column?

Answer 52

Radial column (styloid) – algorithm is simple:

if a VLP was used, insert the radial-most screws to capture the styloid fragment.

If this isn’t enough, supplement with either a fragment-specific plate or K-wires.

If F-S fixation was used, then do one of the latter two options.

(VLP = volar locking plate, F-S = fragment specific)

Question 53

Your fixation on the ulnar column of a complex distal radius fracture?

Answer 53

Ulnar column (if DRUJ instability persists) - options are ORIF ulnar styloid fragment, TFCC repair or pin and cast in supination x 6 weeks (quadricortical); dealer’s choice

Question 54

Re: Terminology in worker’s compensation, define

IMPAIRMENT

Answer 54

Impairment: derangement of anatomic structure or physiologic function

Question 55

Re: Terminology in worker’s compensation, define

DISABILITY

Answer 55

DISABILITY: impairment PLUS considerations of job requirement

Question 56

Re: Terminology in worker’s compensation, define

AGGRAVATION

Answer 56

Aggravation: worsening of a preexisting condition from a NEW incident

Question 57

Re: Terminology in worker’s compensation, define

EXACERBATION

Answer 57

Exacerbation: temporary worsening of a pre-existing condition; eventually receds to former symptom level

Question 58

Re: Terminology in worker’s compensation, define

MAXIAM MEDICAL IMPROVEMENT

Answer 58

Maximum medical improvement: No potential for further functional improvement with continued treatment

Question 59

Re: Terminology in worker’s compensation, define

CAUSATION

Answer 59

Causation: determination of whether occupational injury or exposure led to impairment

Question 60

Re: Terminology in worker’s compensation, define

TEMPORARY TOTAL DISABILITY

Answer 60

Temporary total disability: inability to return to work in any form of gainful employment on a limited time basis

Question 61

Re: Terminology in worker’s compensation, define

APPORTIONMENT

Answer 61

Apportionment: Determination of the degree to which a disorder resulted from occupational or non-occupational conditions

Question 62

Re: Terminology in worker’s compensation, define

Temporary PARTIAL disability

Answer 62

Return to work on a temporary basis with or without certain work restrictions

Question 63

Re: Terminology in worker’s compensation, define

Permanent total disability?

Answer 63

Permanent total disability: permanent inability to pursue gainful employment in any capacity

Question 64

Permanent partial disability?

Answer 64

Reduced capacity to perform work on a permanent basis

Question 65

In worker’s comp, what is the difference between a work restriction, and a work limitation?

Answer 65

Work restrictions: physician judges what the patient should/shouldn’t do

Work limitations: worker’s physical capabilities to perform a task (what they can/can’tdo)

Question 66

When this determination (between work restriction and work limitation) is difficult to make, what can the physician can order ?

Answer 66

Order a functional capacity evaluation (objective evaluation of the worker’s strength, endurance, function, etc.)

Question 67

Anterior drawer test is only 50% sensitive due to what 3 limitations:

Answer 67

1-Acute effusion doesn’t allow for flexion to 90deg

2-Protective hamstrings spasm blocks anterior tibial translation

3-Posterior horn of the MM acts as a doorstop to anterior translation

Question 68

What happens to the knee during a pivot shift?

Answer 68

Pivot-shift facts:

Is subluxated in extension and reduces at around 40deg of flexion from the line of pull of the ITB as it passes posterior to the axis of the knee

Question 69

In grade 3 MCL injuries, what is most often concurrently injured?

Answer 69

The ACL is disrupted 78% of the time

Question 70

Compare locatin of MCL tear vs LCL tear

Answer 70

MCL injury is most commonly at its femoral origin, whereas LCL is usually at its fibular head insertion (palpate it with the leg in figure-of-4 position)

Question 71

Comparing all 3 ACL physical exam maneuvers, which has best sensitivity and best specificity?

Answer 71

Best sensitivity = Lachman

Best specificity:

• Awake = all equivalent
• EUA = Pivot-shift

Question 72

Grade 3 MCL injuries

Answer 72

MCL grading:

• Stable at 0 and 30deg
• Laxity at 30deg = only sMCL
• Laxity at 0 and 30deg = sMCL, POL, dMCL

Question 73

What percent of PLC hae associated common peroneal nerve injury?

Answer 73

25% PLC injuries are associated with common peroneal nerve injuries

Question 74

Two best tests for PLC?

Answer 74

Two best tests for the PLC:

1) Posterolateral rotary test: like the posterior drawer, but the foot is ER 15deg – in this position, the PCL is relaxed, so an increase in the posterior drawer in this position vs. with the foot at neutral suggests PLC injury
2) Dial test (requires a 10-15deg side-to-side difference to be positive)

Question 75

Three best tests for the PCL (posterior cruciate ligament)?

Answer 75

1) Posterior drawer: up to 90% sensitive and 99% specific (better in chronic cases)

Grade I = increased posterior translation vs. contralateral side but tibia still anterior to MFC

Grade II = tibia and MFC equal

Grade III = tibia posterior to MFC

2) Posterior sag: knee positioned like for a posterior drawer and you check the position of the anterior tibia (should be 1cm anterior to the MFC normally) – 79% sensitive, 100% specific
3) Quadriceps active test: knee positioned like for a posterior drawer and patient is asked to contract his quads = this will bring the tibia forward from a subluxated (sagged) position – 54% sensitive, 97% specific

Question 76

What is the antero-medial drawer test used for?

Answer 76

If suspecting a POL injury, do the anteromedial drawer test (like the anterior drawer, but foot is ER 15deg, which isolates the POL)

** Article had said 15 degrees IR but Laprade/Pickell all confirm ER for anterior drawer test to asses PMC.

ER for posterior drawer test testing PLC

IR for posterior drawer test tesing PMC

Question 78

List 9 possible indications for a total wrist arthrodesis

Answer 78

1. RA
2. Posttraumatic OA (SLAC/SNAC)
3. CP/spasticity disorders
4. Complete brachial plexus injuries
5. Salvage after failed arthroplasty (higher rate non-union, requires corticocancellous bone graft)
6. Postinfection degeneration
7. End stage Kienbock
8. Non-union or malunion DR #
9. Preiser osteonecrosis

Question 79

If for salvage after failed wrist arthroplasty, what are 2 considerations in total wrist FUSION:

Answer 79

-higher rate non-union -requires corticocancellous bone graft

Question 80

What is average rate of non-union post wrist arthrodesis?

Answer 80

5%

Question 81

List 5 broad complications of wrist arthrodesis:

Answer 81

1-Infection, non-union (~5%), radiographic loosening 2- ulnocarpal impaction (decreased with triquetral excision) 3-carpal tunnel syndrome 4-extensor tenosynovitis 5-implant failure/prominence

Question 82

How can you avoid ulno-carpal impaction post wrist arthrodesis?

Answer 82

decreased with triquetral excision)

Question 83

3 broad steps to a wrist arthrodesis?

Answer 83

1- Denude and prepare joints

2-Combine with PRC and use as morcelized bone graft (PRC is one option, you don’t have to)

3-Compression plating from distal radius to 2nd or 3rd MC (locking options) vs 2 smooth Stiemann pins into 2nd and 3rd MC’s (use if need MCP arthroplasty or if cannot perform forearm dissection)

Question 85

Best on RCT data, how does a wrist arthrodesis compare over arthroplasty? (5)

Answer 85

Arthrodesis:

• More reliable pain relief
• Lower rates of complications
• Decreased rates of revision
• Both cost-effective (arthrodesis slightly better)
• No definitive difference in clinical outcomes

Question 86

What is the best kind of patient for a wrist arthrodesis? (5)

Answer 86

Arthrodesis best option when:

• Younger than 50
• Manual laborers
• History of infection
• Use of a walker
• Lack active wrist motion

Question 87

List 2 contra-indications for a wrist fusion:

Answer 87

Contraindications:

• Active wrist infection
• Lack of adequate soft-tissue envelope

note:

Lack of bone stock no longer CI with locking plates

Bilateral arthrodeses do well – single study – not CI

Question 88

What is the best position of fusion for a wrist fusion?

Answer 88

Position:

–>10-15 deg extension with slight ulnar dev àbetter grip strength

If bilateral, consider one in neutral for more pro/sup

Question 89

What are 2 possible advantages of operative repair of achilles ruptures (over non-op functional bracing)

Answer 89

• Earlier return to work
• Surgery may have better PF strength

note:

no difference in ankle ROM, strength, calf circumference, functional outcome scores

Question 90

For Achilles tendon rupture, compare the 4 following between non-op (functional bracing) and operative repair:

• Functional outcomes
• Re-rupture rates
• Complication rate
• Return to work

Answer 90

JBJS 2012 Meta-analysis of RCTs:

functional bracing and early motion protocol = similar functional outcomes and rerupture rates(3-5%)

decreased complications (approx. 12% for surgery)

surgery= earlier return to work

Question 91

Functional bracing vs cast immobilization in achilles ruptures?

Answer 91

Functional bracing = faster return to mobility and work, decreased re-rupture rates

Question 92

Ideal time frame from presentation within which to immobilize achilles rupture in PF?

Answer 92

72 HOURS (after which hematoma interposion)

• A JBJS 2011 article talked about decreased rate of rerupture if present within 72 hrs of injury to prevent hematoma formation blocking apposition before immobilizing in PF.
• BUT previous studies have not shown re-rupture rates to correlation with time to presentation

Question 93

What pattern of achilles tendon ruptures absolutely require surgical treatment ?

Answer 93

Achilles tendon avulsions

(i.e. distal tears at calcaneus with our without bone fragment)

Question 95

Is weight bearing in CAM walker detrimental in the rehab of achilles rupture?

Answer 95

It’s good to weight bear:

-Weightbearing in CAM walker decreased ankle stiffness, better quality of life

-No difference on re-rupture rate, functional outcomes or biomechanical tendon properties

Question 96

Biggest worry with percutaneous achilles repair?

Answer 96

-Sural nerve injury (especially in proximal-lateral stab incisions and suture passing)

However, decreased wound infection rates!

Question 97

What are 3 risk factors for wound complications in achilles repair?

Answer 97

Increased wound complications with:

1)smoking, 2) steroids, 3) female

(NOT high BMI, age, DM)

Question 98

Is there a role for biologic adjuncts in achilles tendon repair?

Answer 98

1) PRP – no benefit
2) BM stem cells or mesenchymal stem cells – increased ultimate strength to failure in animal models, no human studies

So neither currently have a proven role as adjuncts to surgical management of acilles ruptures.

Question 99

In the functional rehab protocol for achilles non-op:

1) How long are you NWB?
2) When do you start ROM?
3) When are you WBAT?
4) Remove heel lift?
5) Wean out of boot?

Answer 99

EASY to remember (essentially 2 week intervals):

Week 0 to 2: NWB + crutches

Week 2 to 4: ROM PF to neutral DF only

Week 4: WBAT in boot with heel lift

Week 6: Remove heel lift, still WBAT

Week 8-12: Wean out of boot

Question 100

Return to sport post achilles tendon rupture (regarldess op or non-op)?

Answer 100

Low impact: 6 months

High impact: 9 months

(i.e. soccer, rugby, football)

Question 102

When assessing a pediatric foot mass, list 7 characteristics that should prompt further investigation to R/O malignancy:

Answer 102

Rapid growth

Presdisposition related to syndromes and family hx

Size >5cm

Involvement of deep fascial layers

Heterogenous appearance on MRI

Poorly defined margins

Increased vascularity

Question 103

6 broad categories in the ddx of a pediatric foot mass?

Answer 103

• Benign soft tissue lesion
• Benign vascular lesion
• PVNS/GCT of tendon sheath
• Neurogenic lesions
• Benign bone lesions
• Malignant soft tissue lesion

Question 104

Benign foot soft tissue lesion, what is your differential for a peri-carticular cyst?

Answer 104

1-Ganglion and synovial cyst

2-Synovial sarcom (tender, fixed firm – get MRI, then biopsy/excise)

Question 105

In benign soft tissue lesions of the foot, what are the most common fibroblastic lesions?

Answer 105

Most common – infantile myofibroma and myofibromatosis - <2cm, firm, skin colored or pale red, nonop recommended because high recurrence

Question 106

4 fibroblastic lesions in pediatric benign soft-tissue foot mass:

Answer 106

1-Superficial fibromatoses – small, firm, pea-sized, painful with WBing; Ledderhose disease when in plantar fascia, no imaging required

2-Deep fibromatoses – deep, rapid, infiltrative growth, not known to metastasize, younger age

3- infantile myofibroma and myofibromatosis (most common)

4- Adipocytic – 2/3 lipomas, 1/3 lipoblastomas

Question 107

In pedatric adipocytic foot masses, can you distinguish between liposarcoma and lipoblastoma/lipoma on MRI alone?

Answer 107

Yes for lipoma - Looks like fat on all MRI sequences

NO for lipoblasdtoma - So get a biopsy if locally aggressive, and the treatment is wide resection if symptomatic.

Question 108

What is the MOST COMMON soft tissue tumor in children?

Answer 108

A Benign vascular lesions

Question 109

2 benign vascular lesions in pediatric foot?

Answer 109

Hemangioma - appear within first 3 mos of life, strawberry like appearance, grow quickly until 9-10 mos, involute by age 7-10yrs

Vascular malformation -

if arise after 3 mos or do not involute = vascular malformation; AV or venous malformation

imaging – Doppler US; if asymptomatc (no hemorrhage, thrombosis or sepsis) àfitted pressure stockigns and ASA or other anticoag; if fails àinterventional for sclerotherapy vs vascular for sx

Question 110

Difference b/w PVNS and GCT of tendon sheath in pediatric foot?

Answer 110

PVNS vs GCCT

Similar appearance on MRI – hypointense T1 and T2 due to hemosiderin

GCTTS = almost always extra-art; PVNS = diffuse and intra-art

PVNS – high rate recurrence, can use adjuvant rads

(DDx: synovitis, tenosynovitis, ganglion cyst, lipoma, fibromatosis, synovial sarcoma)

Question 111

What is Trevor’s disease?

Answer 111

(benign bone foot lesion)

Exostoses at epiphyses of long bones may indicate Trevor disease (dysplasia epiphysealis heimelica)

Question 112

List the 2 possible neurogenic lesions in a pediatric foot

Answer 112

Neurogenic Lesions

Neurofibroma – most common, mostly Schwann cells, excision requires excision of the nerve, 3 types: localized, diffuse, plexiform (pathognomonic for NF 1); MRI – target sign

Schwannoma – can be excised without the nerve

Question 114

What modality gives lowest recurrence rate for ABC in pediatric foot?

Answer 114

adjuvant phenol

Question 115

List the 3 Malignant Soft-tissue lesions in pediatric foot in decreasing order of occurence

Answer 115

1) Synovial sarcoma - most common soft-tissue sarcoma in F and A, most juxta-articular, painless, slow-growing, US – well-defined solid lesion, t(X;18); Tx – wide resection and rads
2) Fibrosarcoma – 2ndmost common, good prognosis of infantile vs adult type
3) Liposarcoma – 3rdmost common

Question 116

What is primary blood supply to the humeral head?

Answer 116

Posterior humeral circumflex artery – 64% blood supply to humeral head

Question 117

The 3 major parts of the AO classification for proximal humerus fractures?

Answer 117

AO (A – unifocal extra-art, B – bifocal extra-art, C – articular (fracture dislocations/head splits))

Question 118

Hertel’s criteria for humeral head ischemia?

Answer 118

Humeral head ischemia RF’s (BUT initial ischemia does NOT predict development of necrosis)

• Metaphyseal head extension (head-neck junction to inferior extent of medial cortex) <8mm
• Medial hinge disruption >2mm

Question 119

List in decreasing order of complication rate the surgical options for PHF:

Answer 119

Complication rate: CRPP>RSA>ORIF>HA

Question 120

List in decreasing order of REVISION RATE rate the surgical options for PHF:

Answer 120

Revision rate: ORIF>RSA=HA>CRPP

Question 121

What fracture pattern would you consider fixing in PHF?

Answer 121

Consider OR:

2 – part:

• GT >5mm displacement (decrease risk of subacromial impingement)
• LT fracture with IR impingement

3/4 part: article pushes ORIF if active and <65yo

non-op if poor baseline, inability to tolerate surgery, or valgus-impacted with <1cm displacement of the tuberosities

Question 122

Indicatins for a RTSA? Compcare it to Hemi-arthroplasty

Answer 122

RSA:

3/4 part, >65 yo, comminuted tuberosities

Grammont principles (medializing glenohumeral center of rotation lowering humerus)

HA

The authors from this study recommended HA for patients who are active aged 40 to 65 years with complex four-part fractures or head split patterns that ar likely to have complications with plate osteosynthesis.

Comparing the two techniques:

1. The authors of this article said that the evidence for one of the other is unclear. However one of the main downfalls of RSA was the decreased ER compared to HA. However, as we have learned to better fix the tuberosities (especially by adding bone graft), the ER hs improved in RTSA.
2. Furthermore, the Meta-Analysis presented in the CORR document showed that RSA was better than HA for patients>65yo
3. Another CORR study showed no benefit of HA over non op for PHF aged >65, with better constant murray scores in non op.
4. For patients <65yo who are active, we should be attempting osteosynthesis.

Question 123

2 important technical considerations in hemi-arthroplasty for PHF?

Answer 123

HA:

Humeral head height: 5.6cm from upper border pec major, can assess reduction of tuberosities

>10mm lengthening = excessive tension on supra

Question 124

In fixing PHF, what implant device has best stiffness and load to failure?

Answer 124

IMN with fixed angle blade (vs IMN locking screw, fixed angle small and large frag plates)

Question 125

If you were to peform CRPP (for some reason) in PHF, 2 critical technical considerations?

Answer 125

Medial calcar fixation at least 2cm distal to articular surface to minimize injury to axillary n and posterior humeral circumflex a

Question 126

If choosing ORIF, what aspect of the initial fracture pattern in PHF is a predictor of poor outcome?

Answer 126

initial varus displacement

Question 127

In 3 or 4part PHF, compare ORIF vs HA

Answer 127

ORIF better Constant scores vs HA

osteonecrosis 8 -15%

Question 128

Name 2 risk factors for TMT injuries of the foot

Answer 128

RFs

• Short 2ndMT
• Decreased depth of 2ndTMT mortise

Question 129

Describe 2 possible mechanisms for TMT injuries of the foot

Answer 129

Mechanism

1) Direct – high-energy crush to dorsal foot
2) Indirect (most) – Axial and/or rotational force applied to a PF and stationary foot

Question 130

What are the important stabilizing ligaments at the TMT joint? Rank in order of strength?

Answer 130

Ligaments

• No InterMT Lig between 1 and 2
• Instead, dorsal, IO and plantar Ligs secure 2ndMT to medial cuneiform

Strength

IO (aka “Lisfranc Ligament”) > Plantar > Dorsal

Question 131

What are 2 dynamic stablizers at the TMT joint?

Answer 131

Tib ant and peroneus longus

note: can also become entrapped and preclude reduction

Question 132

What anatomic configuration confers stability at the TMT joint?

Answer 132

Midfoot stability

-3 cuneiforms with their MT bases have trapezoidal configuration

Middle cuneiform and 2ndMT base acting as the “keystone”

Question 134

How does the anatomy at the 4th and 5th TMT compare to medial and middle?

Consequence of fusion at those joints?

Answer 134

Lateral – 4th and 5th TMT jts

=Mobile, shock absorber

Arthrodesis substantially increases plantar forefoot and CC jt pressure

Question 135

3 physical exam findings highly suggestive midfoot TMT injury?

Answer 135

PEx

• Plantar arch ecchymosis – highly suggestive
• Palpate and stress midfoot for pain
• Watch for ++swelling and # blisters – stage if needed

Question 136

What percentage of TMT injuries are initially missed?

Answer 136

20%

Untreated, result in painful post-traumatic DJD and arch collapse

Question 137

What is a classification system for TMT joint injuries?

Answer 137

Classification (doesn’t predict outcome)

A – total joint incongruity

B – Partial joint incongruity

B1 – Medial column

B2 – Lateral column

C – Divergent patterns

C1 – Partial

C2 – Total incongruity

Question 138

List 4 radiographic signs of mid-foot instability

Answer 138

Instability

• >2mm widening of 1st MT to medial cuneiform vs contralateral
• >2mm jt subluxation of TMT
• Any dorsal displacement of MT on Lat view
• Fleck sign = Lisfranc ligament avulsion

Question 140

Role for advanced imaging in TMT joint injuries?

Answer 140

CT – delineate articular comminution, but not dynamic

MRI – valuable to assess subtle lig injuries

Question 141

Outline indicatiion for non-op in TMT joint injuries and duration.

Answer 141

Nonsurgical Indications:

• Stable pattern
• Unable to tolerate surgery

Duration: NWB in SLC vs A/C x4-6wks

Question 142

Initial Surgical Mgmt in tmt/lisfranc?

Answer 142

Initial Surgical Mgmt

• CR for dislocations
• Splint until STs appropriate for OR

Question 143

Goal of Definitive Surgical Mgmt in lisfranc injuries?

Answer 143

Goal – restore functional anatomy of the foot

Question 144

In what order should you be fixing TMT/lisfranc injury?

Answer 144

Order – prox to distal, medial to lateral

Intercuneiform jt –to– 1st TMT jt –to– 2nd MT base in mortise

Question 145

Location/interval of 2 incisions used in operative approach to TMT/lisfranc?

Answer 145

2 incisions

• Medial - between 1stand 2ndray (interval between EHL and EHB)
• Lateral – centered over 4thray (mobilize EDC medially and split EDB)

Question 146

Fixation strategy at each column in TMT/lisfranc injury?

Answer 146

• Medial and middle columns – Rigid fixation
• Lateral column – Flexible fixation
• Assess for cuboid impaction – need to restore lateral column length
• Strayer if equinus contracture present – can lead to increased midfoot loading

Removal of spanning fixation at 8-12wks

Question 147

Joint sparing or joint traversing fixation in TMT/lisfranc injury?

Answer 147

This is controversial

Joint sparing

• Dorsal plate fixation is biomechanically equivalent to transarticular screw fixation, but avoids drilling through articular surface

Question 148

ORIF vs Arthrodesis in Lisfranc Joint injuries?

Answer 148

ORIF vs Arthrodesis

• Post traumatic DJD 25%, despite good reduction
• Arthritis and AOFAS score correlate with quality of reduction
• Increased arthritis in pts with purely ligamentous injury (40%)

Trend towards better results with arthrodesis for purely Lig injury but not definitive.

Question 149

List 6 risk factors for transfusion in pediatric spine surgery:

Answer 149

RFs for transfusion:

1. Longer surgical time
2. >6 levels fused
3. Osteotomies
4. Cobb >50deg
5. NM etiology
6. Low body weight

Question 150

EPO decreases transfusion rate by what percent in pre-op pediatric spine surgery?

Answer 150

Erythropoeitindecreases transfusion rate by 50%

Question 151

3 considerations in pre-op anemia for pediatric spine surgery

Answer 151

• Preop anemia is predictive of postop transfusion
• target a preop Hgb level 5g/dL higher than the surgeon’s preferred transfusion trigger
• Erythropoeitindecreases transfusion rate by 50%

Question 152

Medications associated with increased blood loss in pediatric spine surgery?

Answer 152

Other medications – associated with increased blood loss

• Valproid Acid – platelet-mediated adverse effects
• Antidepressants (SSRI, SNRI, and others)

Discuss stopping preop or anticipating increased blood loss

Question 153

How does TXA exhibit its action?

Answer 153

TXA is an anti-fibrinolytic

Decrease bleeding by inhibiting the degradation of fibrin.

(basically tries to stop plasminogen transformation to PLASMIN, the main fibrinolytic)

Question 154

What is more expensive, autologous blood transfusion or allogenic units?

Answer 154

Autologous blood transfusion

Approx 30% more expensive than allogenic units

Question 155

List 3 Anaesthetic tactics to decrease peri-op blood loss in pediatric spine surgery?

Answer 155

1. Controlled Hypotension

• Lowered BP to decrease blood loss
• Use during exposure, then reverse before deformity correction

2. Epidural blockade
   * Induce vasodilation distal and vasoconstriction proximal to the blocked levels

=Decreased arterial flow to the surgical field (proximal to blockade)

3.Acute normovolemic hemodilution

• Removal of venous blood before incision to decrease hematocrit
• Replace with crystalloid to dilute blood
• Return autologous blood postoperatively

Question 157

Does TXA actually decrease transfusion rates in pediatric spine surgery ?

Answer 157

There have been different studies performed but the RCT that was done showed:

• Decrease blood loss and Hemovac output
• But no difference in transfusion rate.

Other studies have shown decrease in transfusion but they were retrospective.

Note:

TXA Loading dose – 10mg/kg up to 1g

Maintenance 1-100mg/kg/hr

Question 158

Does cell salvage reduce blood loss? or transfusion rate?

Answer 158

Cell salvage

• Does not affect blood loss
• Reduces the need for transfusion
• Cost is greatest drawback

Question 159

What is average transfusion rate in pediatric spine surgery?

Answer 159

17.8% in PSIF for AIS

Question 160

List 4 transfusion triggers in peri-op pediatric spine surgery

Answer 160

Physiologic transfusion triggers

• Tacchycardia
• Hypotension
• U/O <0.5mL/kg/hr
• Acidosis

Historical threshold - <30% Hct

Question 161

Incidence of low back pain/lumbar conditions in elite athletes?

Answer 161

30% (Disk herniation, DDD, spondylolysis)

Question 162

Most common location for LDH (lumbar disc hernation) in elite athletes?

Answer 162

95% occur at L4/5 and L5/S1

Note:

• Most common age 20-35
• R/O Cauda equina and Conus medullaris
  
  • Saddle anesthesia, autonomic dysfunction (overflow incontinence and impotence), leg pain

Question 163

What percent of elite athletes with LDH improve with non-op management?

Answer 163

Nonsurgical

>80% improve within 6wks (>90% in gen pop)

• Give symptomatic relief while LDH resolves naturally
• NSAIDs, PT (core strengthening), Epidural steroids

Question 164

Role of surgery in lumbar disc herniation (elite athletes)?

Answer 164

Surgical

• If nonsurgical Tx fails >6wks
• Laminotomy with discectomy
• 75-100% return to play within 2.8-8.7mos later

Question 165

Prognosis and Return to play after lumbar disc herniations in elite athletes?

Answer 165

Good prognosis,

82% return to play

Question 166

3 most common etiologies of low back pain in elite athletes?

Answer 166

Lumbar disc herniation

Lumbar DDD

Spondylolysis

Question 167

Most important risk factor for lumbar DDD?

Answer 167

Most important RF – Genetic predisposition

Also – aging, occupational hazards, smoking

Question 168

MRI findings in lumbar ddd?

Answer 168

MRI – loss of signal intensity on T2, annular tears, bone marrow/endplate changes

Question 169

Outline 2 Non surgical methods for lumbar DDD

Answer 169

Nonsurgical (Standard of care)

• PT + NSAIDs
• No evidence to support epidural or facet injections

Question 170

List 3 indications and 3 relative contra-indications for surgery in lumbar DDD:

Answer 170

Indications:

• Mechanical LBP with evidence of single-level degenerative disk
• Failure of >6mos nonsurgical Tx
• Localized midline spinal tenderness at the affected level

Relative C/I:

• Narcotic abuse, smoking, unrealistic expectations

Question 171

Is surgery for lumbar DDD successful in elite athletes?

Answer 171

Surgical – unpredictable success

Only consider if nonsurgical has failed, and cannot return to sports

Question 172

In work-up of lumbar DDD, yes or no to provocative discography?

Answer 172

(not recommended)

Can lead to considerably faster progression of degeneration

Question 173

Surgical indication for spondylolysis? (elite athlete, or adolescent athlete)

Answer 173

Surgical

Persistent Neuro Sx or progressive spondylolisthesis despite >6mos nonsurgical Tx

Question 174

Surgical Options in spondylolysis? (algorithm)

Answer 174

Surgical Options:

• Direct pars repair - only for L4 and above and with minmal slippage. Cannot repair L5
• L5-S1 fusion
• +/- Decompression if Neuro Sx
  
  • Usually of exiting L5 nerve

Question 175

Surgical option for lumbar DDD?

Answer 175

Surgery = Diskectomy, fusion vs arthroplasty

Adjacent disk Dz in 36% at 10yrs

But, no improvement with Arthroplasty at midterm f/u

Note: Fusion does not c/i return to play

Question 176

Incidence of spondylolysis in adolescent athletes with LBP?

Answer 176

up to 50% incidence

Spondylolysis = Defect within the pars intraarticularis due to repetitive microtrauma

Question 177

Tenets of non-surgical management for spondylolysis?

Answer 177

Nonsurgical

Acute ==> Activ mod, bracing, rest, PT

• Avoid Lumbar extension
• Sport cessation x3-6mos
• Healing rate >90%

Question 178

What is measured resection in TKA?

Answer 178

Replaces bony resection with metal and plastic of the same thickness to replicate anatomy based on anatomic landmarks.

Question 179

Measured resection TKA best used when (3)?

Answer 179

Best if:

• Clearly identified anatomic landmarks
• Large posterior osteophytes
• Fixed coronal deformity (contracted or attenuated ligaments) - this is because you need intact ligaments in gap balancing to know what cuts to make.

N.B. In severe PF disease, should consider using Gap balancing because whitesides is often not reliable.

Question 180

What is GAP Balancing method in TKA?

Answer 180

Gap Balancing

Use ligament tension relative to a perpendicular tibial cut to judge implant rotation for equal rectangular flexion and extension gaps

Question 182

Describe briefly normal anatomic and mechanical alignment of the lower extremity

Answer 182

Mechanical Alignment (Fig 1)

Femur

• 9deg vs vertical
• 6deg vs mechanical axis

Tibia

• 3deg vs vertical

Question 184

What is condylar lift-off, and what is it a result of?

Answer 184

Condylar liftoff during gait (difference between medial and lateral condylar heights relative to the tibial baseplate) causes increased load transfer and inc PE wear

Question 185

What are the goals of TKA surgery?

Answer 185

Symmetric/Balanced Gaps Flexion/Extension

Accurate Femoral Rotation

Question 187

What are the 2 main surgical techniques in TKA ?

Answer 187

Measured resection

vs

Gap Balancing

(or hybrid of both)

Question 191

When is GAP balancing best used in?

Answer 191

Best if:

Advanced PF DJD or trochlear dysplasia (difficult to identify Whiteside’s)

Minimal osteophytes

Normal collateral ligaments

Question 193

Most common cause of early failure in TKA?

Answer 193

ASymmetric and unEqual Ligament Balance:

ST imbalance and instability is the most common cause for early failure and 2nd most common cause of late failure.

Question 195

Most important technical factors in proper patellar tracking in TKA?

Answer 195

Most important technical factors are femoral and tibial rotation, and restoration of the Q angle to 13-19deg.

How to decrease Q angle

• Lateralize femoral component
• ER femoral component
• ER tibial component
• Medialize patellar component

Question 196

What are the 2 different femoral sizing systems?

Answer 196

Femoral sizing:

1)Posterior referencing

• Constant posterior condylar resection, adjust anterior resection for size
• Use larger size to avoid notching

2)Anterior referencing

• Constant anterior resection, adjust posterior condylar resection for size
• Use smaller size to avoid overstuffing the PJ jt – can cause flexion instability

Question 197

Ideal femoral component position in TKA?

tibial component position in TKA?

Answer 197

Femoral position

• Measured resection – use TEA (most accurate)
• Gap balancing

Tibial position

• Middle of implant is set to medial 1/3 of the Tib Tubercle

Question 198

List the goals (2), references (3), and pitfalls (2) of MEASURED resection TKA:

Answer 198

Measured Resection

2 goals:

• Replace bony resections with prosthesis
• Determine femoral rotation using anatomic landmarks

3 possible References

• TEA – prominence of lateral epicondyle to sulcus of medial epicondyle
• AP axis (Whiteside’s line) – Trochlear sulcus to midpoint of intercondylar notch
• Posterior condylar axis
  
  • 3deg ER should be parallel to TEA

2 Pitfalls

• Landmark reliability– TEA > Whiteside > Post condylar axis
  
  • Gap balancing has least variability and lowest percentage of surgical outliers of rotation (>5deg) – 20% vs 56% for TEA
  • Increased coronal instability – more condylar liftoff through ROM

Question 199

Which method tends to get the femoral rotation wrong more often in TKA?

Answer 199

Gap balancing has least variability and lowest percentage of surgical outliers of rotation (>5deg) – 20% vs 56% for TEA (measured resection)

Question 200

What is the goal of GAP balancing technique (1) and 5 potential pitfalls?

Answer 200

Gap Balancing Goal:

• Optimize flexion and extension gap symmetry

Pitfalls (5)

1. Joint line elevation
   
   • Mismatched gaps are often corrected with femoral resection and increased poly thickness
   • Causes midflexion instability and alters PF biomechanics
2. Midflexion instability
   
   • Femoral implant 5mm anterior and proximal will be balanced at 0 and 90deg, but unstable through arc of motion.
3. Patellar biomechanics
   
   • Contact force increases by 60% for every 1cm of joint elevation
4. Nonanatomic femoral rotation
5. Excessive flexion gap with PCL resection

Question 201

If deciding on surgery for APRI, differentiate between ORIF and Arthrodesis?

Answer 201

ORIF

• Plate fixation:
  
  • Precontoured plate > recon
  • More holes > 2 holes per side
  • Locking = non-locking
  • Most important factors are plate-bone contactand compression at symphysis

Arthrodesis

• Plate fixation + Autograft posterior to symphysis
• +/- Perc SI screw augmentation
• If posterior pelvic pain also:
  
  • SI jt DJD?
    
    • Yes => SI jt fusion (Lateral window II approach)
    • No => leave alone, will improve with anterior fixation

Question 202

what are the advantages of the Hybrid method for TKA?

Answer 202

Hybrid

Combine the strengths of both

• Measured resection – appropriate implant positioning and alignment
• Gap balancing – Joint conformity

Minimize the weakness of each

• Gap balancing – joint line elevation
• Measured resection – suboptimal flexion balance

In short – start with measured resection technique - once jig set based on TEA, tension the knee at 90deg to confirm good rotation based on gap balance

Question 203

List possible causes of anterior pelvic ring instability:

Answer 203

Anterior Pelvic Ring Instability – pathologic motion under physiologic loads at the symphysis

Causes:

• Trauma
• Pregnancy/parturition
• Osteitis pubis (inflammation of pubic symphysis)
• Rheumatologic and Uro/Gyne procedures

Question 204

List the ligaments at the symphysis pubis:

Answer 204

Pubic Symphysis

• Thin layer of hyaline cartilage
• Interposed fibrocartilage disk
• Superior ligament
• Arcuate ligament – inferiorly, ++ strong

Question 205

What portion of the pelvic ring is strongest (anterior or posterior)?

Answer 205

Posterior pelvis ring contributes most of the pelvic ring resistance to deformation.

Generally Motion is limited at Symphysis:

• <2mm translation
• <3deg rotation

Stability at Pubic symphysis

• Sectioning causes 21% decrease in pelvic load tolerance
• Sectioning causes increased rotational stress but does not make SI jt unstable
• Sacrospinous and sacrotuberous ligs don’t provide any substantial stability

Question 206

How can pregnancy lead to APRI (anterior pelvic ring instability)?

Answer 206

Pregnancy

1. Pelvic girdle relaxation
   
   • physiologic change that begins during pregnancy
   • most resolve within weeks of delivery
2. Puerperal symphyseal rupture
   
   • Acute pain and “pop” during delivery
   • most don’t get better non-surgically

Question 207

On an AP Pelvis, what is a normal symphyseal clear space?

What are other images can you order in APRI?

Answer 207

Imaging: AP, inlet, outlet, Judet views

• AP – normal symphyseal clear space is 4.4mm

Flamingo views

• =Single leg stance bilaterally
• >5mm cranial difference = unstable

CT to assess posterior pelvis for ?nonunion/malunion

Question 208

Indications for surgery in APRI (anterior pelvic ring instability)?

Answer 208

Surgical Indications:

• Symphyseal instability(>5mm cranial displacement difference on flamingo views)
• Persistent nonunionon XR/CT
• Puerpal symphyseal rupture (ORIF if <2wks; Arthrodesis if >2wks)
• Failure of nonsurgical Tx x3mos (do Arthrodesis)

Question 209

Tell me the main things about pregnancy-related pelvic ring relaxation (treatment, outcome)

Answer 209

Pregnancy-related pelvic ring relaxation:

• Nonsurgical Tx – 99% resolve by 3mos post-partum
• Lateral recumbancy
• Bracing
• PT

Question 210

Treatment for puerperal symphyseal rupture?

Answer 210

Puerperal symphyseal rupture

Surgical Tx at presentation

• poor results with non-op (press sores, gait issues, post ring pain)
• <2wks – ORIF
• >2wks – Arthrodesis

Question 211

Surgery or no for Osteitis pubis?

Answer 211

Osteitis pubis

• Most resolve without Surgery
• PT, NSAIDs, Steroids, RTx, Activ restrictions, Orthoses
• If refractory – do flamingo XRs to assess for instability
• Tx with Arthrodesis

Question 212

What are 4 risk factors for wound healing issues following TKA?

Answer 212

1. Diabetes
2. Rheumatoid arthritis: review preoperative medication and hold DMARDS 1-2 weeks preop, until 2 weeks postop
3. Obesity
4. Malnutrition
5. Anemia

Question 213

After how long is drainage considered “persistent” following TKA?

Answer 213

• 72 hours.
• >48 hours drainage is a risk factor for deep infection in TKA
• Drainage >5-7 days warrents operative intervention

Question 214

What are the 3 phases of normal wound healing?

Answer 214

1. Inflammation (0- 4 days)

• activation of clotting cascade
• formation of fibrin clot
• neutrophil dominant

2. Proliferation (48 hours - 14 days)

• macrophage dominant
• angiogenesis, fibroplasia & ephithelialization 3. Maturation (day 8 - 1 year) -remodelling -collagen synthesis and remodelling

3. maturation

Question 215

What are several preoperative considrations for a patient with poor soft tissue envelope or previous flap around the knee?

Answer 215

1. Consult microvascular surgeon if previous flap 2. Consult vascular for patient with circulation issues 3. Planned medial gastrocs flap 4. Tissue expanders preop for adherent skin

Question 216

Which arteries supply contribute blood supply to the patella?

Answer 216

All from the patellar anastomoses which has contributions from:

1. Supreme geniculate artery
2. Medial and lateral superior geniculate arteries
3. Recurrent anterior tibial artery
4. Branch of profunda femoris

Question 217

Where should you make your incision in patients with multiple old scars?

Answer 217

1. Most lateral vertical incision even if it nessecitates a lateral arthrotomy
   * More medial incisions interrupt blood supply closer to the source, thus are are at risk for wound healing complications.
2. Cross transverse incisions at 90 degrees 3. Incorporate short oblique incisions into a new vertical incision if near midline 4. Ideal spacing of 7cm between multiple verticle incisions. (AVOID 2.5-5cm skin bridges, unless considerable time since incision was made previously and sufficient revascularization of area)

Question 218

List 3 Strategies for avoiding intraoperative skin necrosis in a TKA.

Answer 218

1. Apex of incisions should form a V. If flattens out to a U- means too much tension and incision should be extended
2. Avoid excessive retraction
3. Full thickness skin flaps to avoid underminining skin
4. Avoid lateral retinacular release to preserve lateral skin oxygenation

Question 219

List 3 nonoperative strategies for persistent wound drainage following TKA.

Answer 219

1. Dry dressings with frequent changes
2. Limit physio for 24-48 hours (flexion of knee >40 degrees after TKA has shown to reduced transcutaneous oxygen saturation around the incision)
3. Consider temporarily stopping LMWH
4. VAC dressings (shown significant reduction in deep infection vs dry dressings)
   
   • indicated for patients draining serous fluid after 48 hours
   • 50mmHg pressure, to avoid skin irritation

No evidence to support use of antibiotics to improve outcome of draining wound.

Question 220

List 5 structures that make up the TFCC

Answer 220

1. Articular Disk
2. Dorsal and volar radioulnar ligaments
3. Ulnocarpal ligaments (ulnotriquetral, ulnolunate)
4. ECU sheath
5. Meniscus Homolog

Question 224

List 7 differential diagnoses for ulnar-sided wrist pain.

Answer 224

Ligamentous

1. TFCC injury
2. DRUJ Instability
3. LT ligament tear
4. UT ligament tear

Osseus

1. Hook of hamate fracture
2. Ulnar styloid fracture
3. Base of 5th metacarpal fracture
4. Trequetral avulsion fracture
5. Ulnocarpal impaction
6. Keinbocks
7. Pisotriquetral arthritis
8. DRUJ arthritis

Vascular - Ulnar artery thrombosis

Neurology - Ulnar neuropathy at guyots canal

Tendinous

1. ECU tendon subluxation
2. ECU tendinitis
3. EDM tendinitis
4. FCU tendinitis

Question 225

List 4 Provocative Tests for ulnar-sided wrist pain and their corresponding pathology.

Answer 225

• Ulnocarpal stress test (Nakamura)
  
  • Wrist in maximum ulnar deviation, forearm neutral rotation and elbow at 90 degrees flexion, axial load is applied while wrist is pronated
  • Assessess ulnar sided pathology ( TFCC, LT tear, arthritis, loose body)
• Linsheid Test
  
  • Positive when creiptus occurs while wrist moves from ulnar to radia and gentle pressure applied to triquetrum
  • LT or Trequetro-hamate joint pathology
• LT joint pathology
  
  • Keinman shuck test - examiner places their thumb or index finger on trequetruma nd pisiform, holding the radial side of the carpus and the lunate with the other, and then moves in opposite directions.
  • Regan Shear test - placing thumb on volar aspect of pisiforma nd other four fingers dorsal on the ulnar side of the wrist. Lunatean the radial side of the wrist are stabilized by the other hand and force is applied through he pisiform from dorsal to volar direction while keeping the other hand stable
  • Derby Relocation test - asking the patient if the wrist or hand feels unstable or loose, and performing three specific tests. One described below:
    
    • Begin in with hand in dorsiflexion and radial deviation with hand in full pronation
    • With other hand, examiner applies a dorsally directed force onto the pisiform with thumb, while other fingers apply a volarly directed counterforce to the the ulna.
    • While maintaining pressure on the pisiform, wrist is brought from radial deviation to neutral which reduces triquetrum.
    • Patient should report sense of instability has disappeared.
• Pisiform Grind test
  
  • Dorsally directed pressure over the pisiform elicits pain.
  • Pisiform-hamate joint arthritis
• Ulnar fovea test
  
  • Direct palpating of the fovea
  • Detect pathology of the UT ligament or fovea disruption of the distal radioulnar ligaments.
• Piano Key Test
  
  • Patients forearm in pronation and hand stabilized by examiner, volar directed pressure on the ulna is applied. If it translates with minimal resistance - positive test
  • DRUJ instability
  • Repeat test in neutral and supination
  • Compare to other side
• ECU Synergy test
  
  • Resisted finger abduction between thumb and index finger causes pain along ECU
  • ECU tendinitis
• ECU instabilty test
  
  • Hold wrist in maximum flexion and ulnar deviation then supinate the wrist against resistance. Look for visible subulxation of ECU tendon
  • ECU tendon instability

Question 226

HIV positive patiets have:

a) higher risk of osteoporotic/fragility fractures
b) higher rates of postoperative sepsis in open fractures
c) higher rates of prosthetic joint infection post-TKA
d) increased risk of acute wound or implant infection

Answer 226

a) higher risk of osteoporotic/fragility fractures

• HIV and HAART results in reduced bone mineral density
• the other options above have no definitive research behind them. multitude of studies for and against each.

Question 227

What preoperative tests should be ordered in a patient with HIV?

Answer 227

1. HIV viral load
2. Preoperative chest radiographs
3. CD4 count
4. Comprehenisve metabolic panel with albumin
5. CBC
6. Protein C & S deficiency

Question 228

Which of the following imaging modalities is most useful in assessing DRUJ instability?

a) Pronated bilateral AP radiographs
b) Pronated girp AP radiographs
c) MRI
d) Dyanmic CT

Answer 228

Dynamic CT

Question 229

What are the mechanisms of action of HAART (highly active antiretroviral therapies) for HIV treatment? (6)

Answer 229

1. Non-nucleoside reverse transcriptase inhibitors
2. Chemokine coreceoptor 5 antagonitsi
3. Nucleotide/nucleoside reverse transcriptase inhibitors
4. Protease inhibitors
5. Fusion inhibitors
6. Integrase transfer inhibitors

Question 230

List 6 risk factors for HIV transmission from a Needlestick

Answer 230

• Deep injury
• Blood visible on the sharp
• Large hollow-bore needle
• High viral load
• Terminal patient from disease
• Procedure involving needle in arteries or veins
• Emergency procedure

Question 233

Which HIV related condition puts a patient at increased risk of intraoperative or postoperative pneumothorax?

Answer 233

Pneumocystis Carnii pneumonia

Question 234

Which is the most reliable risk factor associated with postop infection in HIV positive patients?

a) Absolute CD4 count <200 cells/cc3
b) Viral load >10 000 copies/ML
c) Albumin level <2.5g/dL
d) Patient on HAART therapy

Answer 234

This card was left blank but in skimming the article, I think it should be albumin.

CD 4 and Viral count have both been shown to have increased risks but they say that overal nutrition and albumin are stronger predictors

Question 235

Which is not a risk factor for increased VTE in HIV patients postoperatively?

a) Preoperative halting of HAART therapy
b) Protein C deficiency
c) Protein S deficiency
d) Low CD4 counts

Answer 235

A) Preoperative halting of HAART therapy

• HIV patients 2-10 fold increase of postop VTE vs general population

Question 236

List 4 differences between elderly and young acetabular fractures.

Answer 236

1. Low energy mechanism
2. More frequently involve the anterior column
3. More comminuted
4. If posterior wall involved, more likely to involve a posterior hip dislocation
5. More marginal impaction at medial dome
6. Increased association with femoral head fracture

Question 237

Comanagement of fractures in a geriatric patient by both to surgeon and geriatrician results in reductions in which of the following?

a) reduced hospital length of stay
b) readmission
c) time to surgery
d) complications
e) mortality
f) all of the above

Answer 237

f) all of the above.

Question 238

For which patients should nonoperative management be considered for acetabular fractures?

Answer 238

1. Elderly patients with secondary congruency
2. Patients who’s comorbidities preclude surgical managment

• Important regardless of operative or nonoperative to mobilize the patients reletively quickly to avoid increases in morbidity and mortality associated with bed rest
• In those where pain precludes ambulation, surgery should be performed to allow more rapid mobilization.

Question 239

List 4 surgical options for an elderly patient with an acetabulum fracture?

Answer 239

1. Percutaneous fixation - if adequate bony corridor and minimal comminution. Cannot be used for wall fractures
2. ORIF
3. Delayed total hip
4. Acute total hip

Question 240

What is the name of the staging system used to describe Parkinson’s severity? What two factors is it associated with in regards to postoperativeoutcomes/?

Answer 240

Hoehn and Yahr Grading

• predictive of
  
  • rehabilitation potential
  • risk for implant failure after spine fusion

Question 241

List 4 spine deformities associated with Parkinson’s Disease

Answer 241

1. Camptocormia- “bent spine syndrome” sagital plane deformity with truncated kyphosis but resolves when patient is supine
   
   1. Resolves when supine
2. Pisa Syndrome: coronal plane Spinal deformity with lateral bending deformity at trunk. Absence of vertebral body rotation and flexible compared to idiopathic scoliosis
   
   1. Resolves when supine
3. Antecollis: “dropped head syndrome” - extreme kyphotic deformity fo cervical spine resulting on chin-on-chest deformity
   
   1. resolves when supine
4. Scoliosis

Question 242

All of the following are associated with the GULL SIGN in elderly acetabular fractures EXCEPT:

a) inadequate reduction
b) screw perforation
c) early loss of reduction
d) early joint space narrowing

Answer 242

B

Question 243

List 7 negative predictors of hip survival after ORIF of acetabular fractures.

Answer 243

1. Age >40
2. Hip dislocation
3. Initial displacement >2cm
4. Posterior wall fracture
5. Femoral head fracture/cartilage injury
6. Marginal impaction
7. Non-anatomic reduction

Question 244

Indications for acute THA in elderly acetabular fractures:

Answer 244

1. Full thickness cartilage loss
2. Femoral head impaction
3. >40% impaction of acetabular fracture

Question 245

Which is false regarding outcomes of ORIF and THA vs ORIF alone for treatment of elderly acetabular fractures?

a) Decreased surgical time for ORIF and THA
b) Similar mortality rates
c) Decreased blood loss in ORIF and THA vs ORIF alone
d) Better SF-36 outcomes in ORIF and THA vs ORIF alone

Answer 245

c) Decreased blood loss in ORIF and THA vs ORIF alone

• Cochrane Review
• Combined ORIF & THA
  
  • Slightly Shorter surgery
  • increased blood loss
  • Similar mortality as ORIF alone
  • Bettern SF-36 outcomes
• ORIF alone : better Harris hip scores

Question 246

List the five main modes of total elbow prosthesis failure requiring revision.

Answer 246

1. Infection
2. Aseptic Loosening
3. Fracture
4. Component Failure
5. Instability

Other complications:

• Requring additional surgery
  
  • Nerve entrapment (usually ulnar)
  • Triceps insufficiency
• Increasing morbidity
  
  • Wound infections
  • Paresthesias
  • Fracture

Question 247

List 4 features found in a patient with Parkinson’s disease:

Answer 247

1. Resting Tremour
2. Cogwheel rigidity
3. Bradykinesia
4. Shuffling gait
5. Increased forward posture
6. Loss of fascial expression

Question 248

How do you classify periprosthetic fracture around the elbow? Describe each subtype and associated management.

Answer 248

Mayo Classification (pretty much a ripoff of the Vancouver Classification for Hips)

1. Type I - Involve Humeral Condyle or Olecranon
   
   • Can Managed nonsurgically with immobilization
   • May require fragment excision and advancement of muscle mass
   • Periarticular fractures around olecranon with loss of extensor function should be managed surgially with ORIF (tension band)
     
     • Can’t do a normal tension band with the ulnar compoenent there so try to engage the wires into the cement mantle
     • May need to remove the hardware eventually
2. Type II
   
   • 1- Fracture around the stem in a well-fixed implant
     
     • ORIF the fracture
     • Use paratricipital approach, protect radial n.
     • Bicortical fixation above the prosthesis , unicortical at the implant, supplement with circlage
   • 2- Fracture around the stem, loose implant, good bonestock
     
     • Revision of the component with plate and screw augmentation
   • 3- Fracture around the stem, loose implant, poor bonestock
     
     • Revision of the component with strut graft, circlage
3. Type III - Proximal to the implant
   
   • Nonop management with functional bracing
   • ORIF the fracture if you cant get good alignment nonop

Question 251

List nonoperative management strategies for Parkinson’s patients with flexible spinal deformities.

Answer 251

1. Anticholinergics (alteration in PD medication can cause acute change in spinal alignment, sometimes using an anticholinergic to counteract the dopamine agonists helps)
2. Physical therapy
3. Deep Brain Stimulation
4. Bracing - often poorly tolerated due to ulceration in this population, but good at correcting deformity.

Question 252

Surgical considerations for a patient with Parkinson’s requiring surgery.

Answer 252

• Avoid traditional inhalational agents (halothane) since they interact with levodopa and generate arrhythmias (use newer agents like iso/sevofluorane)
• Hypotension & bleeding (due to poor oral intake and dopaminergic drug use)
• Avoid meperidine (serotonin syndrome when combined with MAO inhibitors)
• Delirium (can last up to 1 week)
• Urinary retention (early foley removal)

Question 253

Postoperative events associated with Parkinson’s.

Answer 253

1. Opoiod Interaction (those with seretonin inhibitory activity like merperidine)
   
   • Can cause seretonin syndrome
2. Postop aspiration
3. Respiratory failure associated with PD associated upper airway dysfunction
4. Prolonged post-op sommnolence, delirium and psychosis
5. Postop urinary retention

Question 254

Schroder et al’s indications for spinal surgery in those with Parkinson’s and HY scale score 3 or greater (2).

Answer 254

1. Myelopathic
2. Neurologic compromise

• Essetially high risk for complications and infection

Question 256

What is the rate of infection following TEA?

What is the most common organism causing PJA following TEA?

Answer 256

• 3-8% infection (higher than other arthroplasties. Thought to be due to the procedure being done in a large proportion of rheumatoid)
• Staph Epidermidus
  
  • Also high amount of S. Aureus.
  • More difficultly eradicating infection if S. Epidermidus is the causative agent

Question 258

Which of the following modalities has the most evidene to provide a positive effect regarding pain control?

a) Icepacks/Ice Compression
b) Ultrasound
c) TENS
d) Iontophoresis

Answer 258

a) Icepacks/Ice Compression - found to be effective for pain management edema control and delayed onset muscle soreness.

• Ultrasound has little evidence in the realm of rehabilitation when not combined with other modalities.
• There is a role for heat therapy in regards to tissue extensability
• Limited role for iontophoresis in tennis elbow
• TENS have shown little clinical utilty on their own.

Question 259

Whic is the following is not an indication for cryotherapy?

a) Pain modulation
b) Tissue extensability
c) Edema Control
d) Delayed Onset Muscle Soreness

Answer 259

b) Tissue extensability - heat therapy has shown to be effective here, but not cold.

Question 260

Name 3 tissues targeted in electical stimulation therapy.

Answer 260

1. Tissue (skin, fat, fascia)
2. Muscle
3. Nerve

Question 261

In which of the following has Neruomuscular Electronic Stimulation (NEMS) therapy shown to have a benefit?

a) Total Knee Arthroplasty
b) Achilles Repair
c) Total Hip Arthroplasty
d) Quads Strengthening Post ACL

Answer 261

d) Quads Strengthening Post ACL

Question 262

What are the 3 etiologies of osteoporosis in patients with SCI?

Answer 262

1) Hormonal - decreased sex hormones
2) Unloading - Wolff’s law
3) Denervation - Effective sympathectomy due to the SCI causes disorganized vasoregulation leading to poor bone formation

Question 263

Do SCI patients get osteoporosis of their upper extremities?

Answer 263

Yes - which confirms that osteoporosis is not just secondary to off loading (also hormonal and denervation)

Question 264

Which vertebrae in SCI maintain BMD?

Answer 264

Lumbar

Question 265

Bone loss is diffuse in patients with SCI, what bone is spared of bone loss, and which is the most vulnerable?

Answer 265

Skull is spared and Knee is most vulnerable

Question 266

What are the 3 stages of bone loss in SCI patients?

Answer 266

1) Acute - < 4 months
2) Subacute 4-16 months
3) Chronic >16 months - Peak bone loss occurs at 16 months in the LE

Question 267

How do patients with SCI heal bone?

Answer 267

With exuberant callus but quality is questionable

Question 268

What is the mainstay of management for fractures in patients with SCI?

Answer 268

Non op with well padded casts and regular skin checks.

ONly 7% get surgery Do NOT use Ex fix but frames are ok. ORIF has been associated with SHORTED LOS

When patient presents with what looks to be a fracture, dont; forgot to RO infection

Question 269

In the management of Long Bone Fractures in SCI Patients:

What are 3 fracture prevention methods? (2 drugs and 1 non drug) and what is one drug that increases fracture risk?

Answer 269

1) Bisphosphonates - may be helpful in first 6 months
2) Thiazides - can decrease fracture risk by 25%
3) Physical Therapy - unclear if it’s for sure helpful, but thought to contribute

Anticonvulsants (Phenytoin) INCREASES risk of fracture

Question 270

What is one possibly fatal complication of fractures in SCI, and how does it present?

Answer 270

Autonomic dysreflexia - Hypertension, shivering, anxiety, and headache, nausea, diaphoresis and flushing.

Question 271

What gene is Marfans from and what chromosome?

Answer 271

FBN1 and Chromosome 15

Question 272

What are the 2 main non orthopedic findings in Marfans

Answer 272

Superior lens dislocation and aortic root aneurysm

Question 273

What are the orthopedic findings of Marfans?

Answer 273

Scoliosis, tall stature, pes planovalgus, pectus excavatum, long fingers (look for wrist and thumb sign), dural ectasia, acetabular protrusion

Question 274

If you have an athlete who has Marfans, how should you counsel them RE athletics?

Answer 274

No quick bursts of energy or strength and no contact sports

Question 275

Which rotator cuff muscle is the primary dynamic stabilizer to posterior tanslation?

Answer 275

Subscapularis

Question 276

What is the primary ligamentous stabilizer to POSTERIOR translation when the shoulder is in forward flexion and IR? Which ligament augments the stability when the shoulder is in aBduction and aDduction?

Answer 276

Posterior IGHL

Shoulder in ABduction: MGHL

Shoulder in ADDuction: SGHL

Question 277

What role does the rotator interval have in posterior stability?

Answer 277

The RI contribution to stability is controversial. It helps to prevent INFERIOR and POSTERIOR translation when the arm is in adduction.

Question 278

What makes up the rotator interval?

Answer 278

SGHL, MGHL, Capsule, Biceps, CHL

Question 279

What is the most common symptom of posterior shoulder instability?

Answer 279

Deep pain in the posterior aspect of the shoulder

Question 280

How is Posterior shoulder instability managed? (Discuss the algorithm for posterior shoulder dislocation)

Answer 280

If no symptoms of posterior shoulder instablity OR MDI is diagnosed, then do rehab for >3 months. If this fails, then you can proceed to the usual posterior shoulder instability algorithm.

If there is posterior shoulder instability symptoms or recurrent dislocations, then you need to evaluate for glenoid bone loss.

a) If <10% glenoid bone loss - do posteiror inferior capsular plication and labral repair
b) if 10-20%, Same but CONSIDER Bony augmentation
c) If >20% then open vs arthroscopic posterior inferior glenoid bony augmentation with iliac crest bone graft, or allograft (distal tibia is authors preference)

Question 281

Does open or arthroscopic stabilization have better outcomes?

Answer 281

Both are acceptable but arthroscopic has lower recurrence with higher return to play

Question 282

What is the most common mechanism of posterior shoulder instability?

Answer 282

Recurrent micro trauma (Repetitive bench press, overhead weight lifting, rowing, swimming)

Question 283

What are the 4 etiologies of posterior shoulder dislocation?

Answer 283

1) Acute trauma 2) Repetitive Microtrauma (most common) 3) Insidious onset (Think MDI and high Beighton score>4/9) 4) Voluntary - Either voluntary positional - i.e. subluxation in a provocative position (FF+IR). These patients SHOULD be considered for surgery OR Voluntary Muscular instability - arm is Adducted (non positional dependent). These patients should NOT be considered for surgery

Question 284

What are 5 physical exam tests for posterior shoulder instability?

Answer 284

1) Jerk test - Shoulder at 90 degrees of FF, IR and the elbow is pushed posteriorly 2) Kim test - Shoulder is 90 abducted. Apply an inferior force while moving the arm 45 degrees of FF 3) Sulcus test 4) Load and shift test 5) Posterior stress test - FF of 90, IR and adduction and then load the shoulder, pushing posteriorly

Question 285

Name 5 risk factors associated for periprosthetic TKA fractures

Answer 285

Osteoporosis, age, prolonged steroids, neurologic disorder, inflammatory arthritis, obesity

Question 286

What’s the most important factor that contributes to an interprosthetic femoral fracture?

Answer 286

Cortical bone thickness

Question 287

What are the options for periprosthetic fracture maangement?

Answer 287

1) ORIF (Nail or plate) 2) Revision instrumentation (constraied and unconstrained) 3) Allograft prosthetic composites (However these have grossly gone out of failure due to poor outcomes even in young patients)

Question 288

How would you manage a periprosthetic TKA that is loose but has good bone stock and defects <2cm?

Answer 288

If ligaments stable - unconstrained TKA If ligaments unstable - Constrained TKA

Question 289

How would you manage and periprosthetic fracture in a TKA that requires revision if there was poor metadiaphyseal bone stock and defect >2cm?

Answer 289

If Unconstrained defect, then need to consider allograft composite TKA for young patient and femoral/tibial endoprosthesis for elderly patients. If it’s a constrained defect then you can use metal augments

Question 290

To set your femoral rotation in a revision TKA, what landmark is still available?

Answer 290

Transepicondylar is msot often still present, whereas whitesides and posterior condyles are absent

Question 291

What are the two most important surgical considerations that will lead to successful surgery in revision TKA?

Answer 291

Appropriate soft tissue coverage and maintenance of the extensor mechanism

Question 292

What are the 4 main goals of revision arthroplasty for periprosthetic fractures?

Answer 292

Knee alignment rotation, stability and early mobilization

Question 293

WHat muscles does the recurrent branch of the median nerve supply?

Answer 293

Abductor pollicis, opponens policis and superficial part of the flexor pollicis brevis

Question 294

Where does the palmar cutaneous branch of the median nerve arise?

Answer 294

volar radial side of the foream, between 4-10cm proximal to the wrist crease. usually runs B/w PL and FCR

Question 295

How common is a bifid median nerve?

Answer 295

1-19% of patients have it and need to be aware that there is a higher incidence of CTS in these patients.

Question 296

What are the 4 variations of the recurrent motor branch of the median nerve?

Answer 296

1) Subligamentous (31%) 2) Ulnar take off 3) Extraligamentous (46%) 4) Transligamentous (23%)

Question 297

Where should the incision be for a CTR?

Answer 297

No true safe zone but make an incision along the long axis of the 4th digit. This seems to pose the least risk

Question 298

What are the 2 strongest risk factors for crankshaft phenomenon, and wjhat are 4 other possible risk factors?

Answer 298

Skeletal immaturity at the time of PSF and Risser 0. Others: RVAD>20, Actual age<11, skeletal age<10 and open triradiate

Question 299

WHat type of vertebral growth causes the crankshaft phenomenon?

Answer 299

Axial plane growth

Question 300

How many grwoth plates are there in the vertebrae?

Answer 300

There are 3 Transverse gorwth plates

1. Spinous process,
2. base of each pedicle,
3. and the endplates.

Longitudinal growth occurs from the endplates

Question 301

WHat are 3 radiographic findings to help diagnose crankshaft?

Answer 301

1) Cobb progression >10 2)RVAD >20 Apical vertebral rotation >5

Question 302

Crankshaft can happen with any type of scoliosis and even when using pedicle screws, what is the one type of growing construct that has the lowest rate of this phenomenon?

Answer 302

Shilla Growth Guidance System (I can’t find this on the Medtronic website, but essentially it sounds like you put non polyaxial screws at the apex and polyaxial screws elsewhere. You can then grow the construct with the rods because the rods are not firmly attached to the pedicle screws….

Question 303

In which group are Distal Humerus Fractures expected to increase the most in the future?

Answer 303

Elderly, independent patients >80yo

Question 304

What is the most important structure in the DHF when it comes to fixation?

Answer 304

The trochlea

Question 305

What is the most common fracture type in DHF in patients >65

Answer 305

Type C

Question 306

What type of DHF is most at risk of nonunion if treated non op?

Answer 306

Low Type A and Type C

Question 307

How do surgical complications compare in the elderly to a younger population when DHF are treated surgically?

Answer 307

The same (but young patients still have better outcome scores)

Question 308

What is the goal of surgical management of the DHF??

Answer 308

○ Painless elbow with 30-130 ROM ○ And if you have to choose, get it anatomically aligned and fix stiffness later ○ FYI - can accept shortening in the metaphysis, but MUST get the trochlea width correct. If you shorten the metaphysis, then you need to burr out the olecranon fossa

Question 309

What is the overall risk of DHF surgical complications?

Answer 309

30%

Includes:

• stiffness,
• infection,
• SSI,
• ulnar nerve injury,
• malunion,
• non-union

Question 310

What is a modifiable risk factor for DHF surgery that can decrease complications?

Answer 310

Surgical fixation within 48-72 hours (has been shown multiple times)

Question 311

Are locked plates necessary for DHF?

Answer 311

No, not in the young patient with good bone but in osteoporotic bone then you should use locked plates.

Question 312

What’s the BMD cutoff where you should choose locked plates for DHF?

Answer 312

420

Question 313

What is the main type of failure in DHF fixation?

Answer 313

Torsional

Question 314

Although it is still unclear whether parallel plating vs 90-90 plating is superior, how have cadavre studies shown one to be better than the other?

Answer 314

Parallel plating had greater axial (p<0.005) and external rotation (p<006) stability

Question 315

Although the only clinical study on 90-90 plating vs parallel plating in the elderly did not show any difference in ROM or time to union, if 90-90 plating WERE to fail, what would be the mechanism of failure?

Answer 315

Nonunion secodnary to loosening of the posterior lateral plate

Question 316

What are independent risk factors for poor outcome post surgical fixation in DHF?

Answer 316

Age >50, Osteopenia and open fracture

Question 317

How does ORIF and TEA compare in the elderly patient (>65yo) group?

Answer 317

TEA has better DASH and MEPS scores and shorter surgical durtation (McKee) - All Statistically significant

There was also a trend (although did not reach statisticaly significance) for greater ROM and less re-operation for TEA

Question 318

What is the most common site of ulnar nerve compression?

Answer 318

Osbornes ligament at cubital tunnel

Question 319

What are the sites of compression of the ulnar nerve?

Answer 319

Ligament of struthers Osbornes ligament (cubital tunnel) Two heads of FCU Deep Fascia of FCU FDS Fascia Anconeus Epitrochlearis Guyons Canal

Question 320

What is the differential diagnosis of ulnar nerve symptoms?

Answer 320

C8-T1 radiculopathy Thoracic outlet symdrome Ulnar nerve compresison at Guyon’s canal

Question 321

What are other causes of ulnar wrist pain?

Answer 321

Pisotriquetral OA Hook of hamate fracture (think about this in golfers!)

Hypothenar hammer syndrome (when there is decreased blood flow to the digits due to using the hypothenar emminence as a “hammer” - it can damage the ulnar artery.

FCU tendinitis

Question 322

What are the presenting signs of ulnar neuropathy?

Answer 322

muscular atrophy in 1st webspace Wartenberg sign (little finger cannot adduct), Froment (thumb IP hyperflexion due to inability to adduct the thumb) Jeanne sign (thumb hyper extension due to overpull of EPL) Claw hand - advanced

Question 323

What tests can you do to assess for cubital tunnel syndrome?

Answer 323

Nerve percussion - Tinnels at elbow

Elbow flexion test - Flex elbow and extend the wrist

Flexion-compression Test - compress Ulnar nerve while flexing the elbow

Scratch collapse test (unclear if this actually is reliable)

Question 324

What is a positive EMG test?

Answer 324

<50m/s velocity drop or >10m/s difference across different areas of the elbow

Question 325

When do you offer surgery for ulnar nerve symptoms?

Answer 325

If there is atrophy or impaired 2 point discrimination In moderate disease, 33% will require surgery In Severe disease, 66% will need surgery.

Question 326

Who should you NOT do an ulnar nerve transposition on?

Answer 326

Those with vascular concerns because you need to dissect anteriorly and may compromise vascularity to the flap - increased risk in someone who already has impaired vascular status

Question 327

In cubital tunnel syndrome, one option is to do a medial epicondyle osteotomy. Greater than what % causes elbow instability?

Answer 327

>19% (O’Driscoll) When doing the osteotomy, need to be careful to preserve the MCL

Question 328

What the consensus on ulnar nerve transposition?

Answer 328

Unclear which is better, but might want to consider transposition when the nerve is hypermobile and in the post-traumatic cubital tunnel situation (i.e. patient has had elbow dislocation, DHF etc) Should also consider for revision surgery where all areas of compression had previously been decompressed

Question 329

What is the most common workers compensation claim in the US?

Answer 329

Back pain

Question 330

When looking at ACDF, what do worker compensation patients tend to have as end results?

Answer 330

increase pseudoarthrosis, increased pain scores, higher revision rates

Question 331

What is the only type of spine surgery that has shown similar outcomes for workers comp vs normal population?

Answer 331

Transforaminal lumbar interbody fusion.

Discectomy ACDF, and anterior lumbar IB fusion all showed worse results in workers comp patients

Question 332

What are the 4 risk factors for poor outcomes in workers comp patients?

Answer 332

1) Narcotic use within 7 days of injury
2) Chronic opioid use (>1yr)
3) litigation status - 9.5x more likely to have long term functional limitations
4) Mental health issues - get psychology involved!

Question 333

What is the most common implant type that has hypersesitivity reaction?

Answer 333

metal on metal and resurfacing

Question 334

What are the top 3 types of metal allergy?

Answer 334

Nickel (#1) Cobalt Chromium

Question 335

What are 7 risk factors for metal allergy?

Answer 335

female, piercings, history of hand eczema, metal allergy in first degree relative, Hx of smoking, following well functioning arthroplasty and following failed arthroplasty

Question 336

What is the most common type of allergic reaction for ortho implants?

Answer 336

Type IV - T cell mediated (not antibody) Examples: contact dermatitis, chronic transplant rejection, MS

Question 337

What imaging should you use to help with allergy diagnosis?

Answer 337

xrays to look for loosening and malposition, along with metal reduction MRI to look for pseudotumor and aseptic lymphocytic vasculitis-associated lesions (ALVALS) *** MRI and US have the same ability to detect AVALS

Question 338

What will a joint aspirate show if suggestive of allergy?

Answer 338

elevated white count and high % of monocytes. (These findings are NOT specific for allergy, just suggestive) NO DOT test for metal ion concentration (no benefit in diagnosis)

Question 339

What other orthopedic related non metallic implants can cause hyper sensitivity reaction?

Answer 339

PMMA, Bioabsorbable implants, suture materials

Question 340

How should you manage patients with MoM hips?

Answer 340

1) Low Risk - well fixed with no symptoms - MOonitor yearly
2) Moderate Risk (well fixed, well positioned who exibit some symptoms - follow Q3-6months
3) High Risk - Severely Symptomatic with high ion levels (>10ppb) and malposition - revision is generally considered

Question 341

If the patient needs TKA revision, what kind of implants will you select?

Answer 341

Convert Co-Cr to Zirconium femoral implants, and titanium tibial trays with poly, or ALL poly.

Question 342

When does the meniscus vascularity of a child become the same as an adult?

Answer 342

10 yo

Question 343

Which meniscus is more common to be discoid?

Answer 343

Lateral

Question 344

What are some traits of the discoid meniscus that may lead to tearing?

Answer 344

Decreased vascularity, decreased number of collagen fibers with disorganized course, and there can be mucoid degenration

Question 345

What is the classification for discoid meniscus?

Answer 345

Watanabe I- Complete co verage of the tibial plateau and stable to probing II- 80% coverage of the tibial plateau and stable III- unstable to probing (There are no posterior meniscotibial attachments) - only posterior attachment is Ligament of Wrisberg

Question 346

What are the 4 radiographic signs (xray) of a discoid meniscus

Answer 346

Squarring of the femoral condyle, cupping of the tibial condyle, increased lateral joint space, decreased size of the lateral tibial spine

Question 347

What do you see on MRI for discoid meniscus?

Answer 347

Need to have 3 cuts of 5mm where there is continuity from anterior to posterior (Bowtie sign)

Question 348

What is better to diagnose a discoid meniscus? Physical exam or MRI?

Answer 348

Physical exam. MRI has lower sensitivity

Question 349

How do you manage discoid meniscus?

Answer 349

1- Asymptomatic - monitor. 2- Symptomatic - Saucerization and then assessment of meniscal stability. Stabilize meniscus with sutures

Question 350

How much meniscal rim should be left when doing saucerization?

Answer 350

6-8mm

Question 351

What is the only significant risk factor for poor outcomes post discoid meniscus surgery?

Answer 351

Older age

Question 352

When comparing discoid and non discoid patients who had total meniscectomy and subequently went on to meniscal transplant, what is the one difference that has been noted in post op outcomes?

Answer 352

Discoid meniscus group had significantly decreased ROM

Question 353

How much vitamin D is recommended per day?

Answer 353

>600IU for patients 19-70, and 800 for patients >70

Question 354

What are the effects of Bisphosphonates on arthroplasty?

Answer 354

aids in bony integration, improves implant survival and can help prevent fractures. DO NOT stop them perioperatively

Question 355

What type of patient should cemented femoral stems be considered for?

Answer 355

The elderly with poor bone quality due to the risk of fracture and subsidence

Question 356

WHat are 4 risk factors for periprosthetic fractures in THA?

Answer 356

Female

Age

Non cemented implants reivision surgery

Question 357

How do you manage a patient with an atypical femur fracture who also needs THA?

Answer 357

Fix the fracture first and then convert to THA once fracture is healed. This prevents the need for a long stemmed THA

Question 358

What 2 conditions that can lead to AVN of the femoral head are associated with worse outcomes post THA?

Answer 358

Renal failure (or transplant) and Sickel cell

Question 359

When doing a THA on a Sickel cell patient, what are 4 intra-op considerations that you need to be mindful of?

Answer 359

1) SCD patients have smaller Bones 2) Confirm small implants are available pre op 3) Can have deformities in the proximal femur, poor bone quality and sclerotic canals 4) Hip dislocations can be very difficult due to protrusio, large osteophytes and intra-articular adhesions

Question 360

What peri-operative considerations need to be considered for SCD patients?

Answer 360

Good hydration, good O2 (to prevent sickling), and may require Transfusion

Question 361

Paget’s disease has a specific wear pattern of hip OA what is it?

Answer 361

concentric and Medial joint space narrowing

Question 362

Perioperatively, what are 2 considerations for patients with Pagets?

Answer 362

They have increased risk of intra-op bleeding due to hypervascular abnormal bone. As a result, bisphosphonates should be considered as they decrease bone activity They are also at higher risk of HO and periprosthetic fracture

Question 363

What disease is associated with shepards crook deformity?

Answer 363

Fibrous dysplasia Deformity of the proximal femur (when the proximal femur is severe varus)

but can also be Paget’s or OI!

Question 364

Before performing a THA on an OI patient, what other testing should be done?

Answer 364

C-spine xrays to RO cervical instability

Question 365

In acetabular protrusio, what are 2 alternative options to hip dislocation?

Answer 365

1) In situ neck cut 2) Remove the overhanging portion of the acetabular wall or ossified labrum

Question 366

In acetabular protrusio, what are the main goals of reconstruction on the acetabular side? (3)

Answer 366

reinforcement of the medial wall Lateralization of acetabular implant rigid fixation with appropriate coverage of the defect

Question 367

How do you calculate the Dorr ratio and what is the Dorr classification?

Answer 367

Canal diameter 10cm distal to the LT DIVIDED by the canal diameter at the LT Dorr A = <0.5 Dorr B = 0.5-0.75 Dorr C >0.75

Question 368

When using a gastroc flap, how far away can the defect be?

Answer 368

15cm from the knee joint

Question 369

What anatomic structure can be used to identify the interval betwen medial and lateral gastroc heads?

Answer 369

The medial dural cutaneous nerve (branch of the tibial nerve)

Question 370

How far distal do the 2 heads of the gastroc extend (in relation to the medial and lateral malleoli)?

Answer 370

Medial extends to 5cm above the distal tip of the medial malleolus, while the lateral extends to 10cm above the lateral malleolus ti[

Question 371

What is the vasculature to the gastroc heads?

Answer 371

Medial and lateral sural arteries, along with 1 or 2 veins. (branches of the popliteal artery)

Question 372

What are 3 contraindications to a gastroc flap?

Answer 372

1) Active purulent infection 2) Defect >15cm from the knee joint 3) Patient with serious malnutrition reuslting in inability to heal surgical insult

Question 373

Is a pre-op CT angio necessary for gastroc flaps?

Answer 373

No. Only if there is history of previous injury to leg vasculature

Question 374

How can you increase the length of the gastroc flap? (2)

Answer 374

1) Can release gastroc from the femoral condyle (gives 5cm) 2) pie crust the gastroc fascia, or remove it all together

Question 375

WHat are 2 functional donor site morbidities from a gastroc flap?

Answer 375

1) Decreased push off strength of ~7% 2) Contra lateral stride length is decreased to reduce the demand on the ipsilateral calf muscle

Question 376

Which 2 ligaments are desrupted in a anteriomedial rotatory instability injury?

Answer 376

MCL and Posterior oblique

Question 377

WHat are the 3 layers of the knee and it’s contents?

Answer 377

I - Sartorius fascia and retinaculum - Pes and saphenous nerve run between layers I and 2

II- Superficial MCL, POL, Semi-membranosus, MPFL

III- Deep MCL and joint capsule, coronary ligament

*** There is a newer description of the medial side of the knee which describes it in thirds - Patellar tendon to anterior edge of sMCL, width of sMCL, and PMC (i.e. posterior edge of sMCL to gastroc head)

Question 378

What are the 5 components of the posterior medial corner of the knee?

Answer 378

1) POL
2) Oblique popliteal ligament
3) Semi membranosus
4) Posterior medial joint capsule
5) Posterior horn of the medial meniscus **Superficial and Deep MCL are NOT typically considered part of the PMC)

Question 379

What are the 5 expansions (insertions) of semi membranosus?

Answer 379

1) POL 2) OPL 3) Posterior medial tibia 4) Par reflexa 5) popliteus poneurosis expansion

Question 380

What is the most commonly injured structure in the posterior medial knee?

Answer 380

POL

Question 381

What are 3 injuries that can occur to the semimembranosus

Answer 381

Avulsion

Tendon rupture

Tenidinitis

Question 382

What causes the “reverse Segond” fracture?

Answer 382

Bony avulsion of the meniscotibial ligament insertion and occurs in association to the PCL rupture.

Question 383

WHat are 3 physical exam tests to diagnose and PMC injury?

Answer 383

1) Anterior drawer with the foot externally rotated to 10-15 degrees - will see anterior translation of the anterior medial tibial plateau

2) Valgus stress test with the knee at 30 degrees and externally rotated foot. Look for rotatory component of medial tibial plateau in relation to femur

3) Valgus stress test at 0 and 30 - If the knee opens with Valgus stress in 30 then think MCL, but if opens at 0 and 30, then need to RO PMC

4) Posterior drawer test with foot in internal rotation

**If you’re having trouble remembering which way the foot points, it points in the same direction of your rotatory force - i.e. for anterior drawer, you are also applying a ER force, trying to get the medial tibia to move forward (foot is ER’d for anterior drawer). Meanwhile, for posterior drawer you are IR’ing the tibia to seee if the medial tibia goes back (Foot is IR in posterior drawer for PMC).

Same for PLC - you do posterior drawer with foot ER’d and you apply and ER force to see if the lateral tibial plateau goes posteriorly

Question 384

How are MCL and PMC injuries managed?

Answer 384

1) Gr I and II MCL extending to the PMC can be treated non op
2) Otherwise, there are no clear cut indications for surgical maangement of PMC. But should be considered in multi lig knee injuries, those with gapping with valgus stress at 0 those with Stener type MCL injuries and PMC injuries that are avulsed.

Question 385

If the MCL and POL are reconstructed (Laprade technique - can look it up), at what degree of knee flexion should the MCL and POL be tightened at? Hint: They are different

Answer 385

MCL - 20 degrees of flexion and varus POL - Full extension and neutral rotation

Question 386

When the Lean Method in health care was implemented at the Seattle Spine group, how did the overall complication rate improve?

Answer 386

Decreased from 52 to 16%

Question 387

How can the “Lean Method” help orthopedics?

Answer 387

Can reduce variablity within orthopedic centers and improve order sets, use of drugs and post op mobilization. Essentially, it standardizes everything so that it is the most efficient (time and cost) process, while still being safe and effective. Requires Multidisciplinary input, including the patient (customer)

Question 388

If your ACL or PCL repair fails, what 2 other areas of the knee must be assessed to assess stability?

Answer 388

PMC and PLC. both of these add rotatory support and can be contributory to instability

Question 389

the POL and sMCL were thought to be the same previously, but their origin and insertion are different. Describe origin and insertion for both

Answer 389

sMCL:

• Origin is posterior and proximal to medial epicondyle.
• Insertion: Anterior Proximal Tibia

POL:

• origin: Is posterior and DISTAL to adductor tubercle (just inferior to Gastroc Tubercle)
• Insertion: Has 3 “arms” but CENTRAL arm is most important and runs at an angle 25 degrees posteriorly and inserts on posterior tibia/capsule.
• This is the part of the POL that is reconstructed in Laprade technique of PMC reconstruction

Question 390

What are the 3 injury patterns seen in PMC injuries? i.e. what structures are involved in each pattern?

Answer 390

1) POL and capsular arm of semimembranosis (70%)
2) POL and complete peripheral meniscal detachment (30%)
3) POL and capsular arm, and peripheral meniscal detachment (19%) POL was injured in 99% of these knees

Question 391

What mechanism of injury will most likely lead to POL injury?

Answer 391

tibia ER and valgus stress Direct Valgus will more likely lead to isolated MCL

Question 392

List the most useful physical exam findings regarding rotator cuff tears:

Answer 392

1. Weakness to manual muscle testing with resisted abduction or weakness to resisted external rotation with arm at side
2. Drop arm sign
3. External rotation lag sign
4. Painful arc

Question 393

Under which acromiohumeral distance do findings of supraspinatous tears increase?

Answer 393

Full thickness supraspinatous tears found in 90% of patients in which distance between humeral head and undersurface of acromion < 7 mm

Question 394

List the 3 sites used for Subacromial injections, and which is the most challenging?

Answer 394

1. Anterior Approach
   
   1. most challenging because of CA ligament anteriorly and anterior acromial spurs in some patient
2. Lateral approach
   
   1. Allows easy access to subacromial space
   2. Provides flexibility for addressing both anterior and posterior abnormalities
   3. Needle should be aimed just below lateral and inferior border
3. Posterior approach
   
   1. When pain is primarily posterior, injection into posterior site can be used

Question 395

Has ultrasound been shown to increase accuracy for subacromial injections?

Answer 395

No

Aly et al - systematic review of 4 cadaver studies and 9 clinical studies, no difference in accuracy fo injections in to subacromial space when performed with or without ultrasounaography

Question 396

List 4 physical exam tests for AC joint pathology.

Answer 396

1. Palpation of AC joint
2. Cross- body adduction stress test
3. Arm extension test - shoulder and elbow are flexed to 90, and then the patient abducts the shoulder while the examiner applies an adduction force
4. Active compression test - O’Brien’ Test

Question 397

What factors make AC joint injection difficult?

Has ultrasound been shown to be more accurate for AC joint injection?

Answer 397

1. Small joint with fibrous capule
2. Joint obliquely oriented
3. Small meniscus occupies joint space between distal clavicle and acromial articulation

• Ultrasound assisted injections more accuracy than blind (94% vs 68%), Aly et al.
• Care should be taken to avoid advancing the needle too deep to avoid injecting the subacromial space instead.

Question 398

What possible pathologies can be relieved by glenohumeral joint injection? Which two approaches could you use? and which is better?

Answer 398

Many pathologies which makes GH injections a difficult diagnostic tool.

1. Frozen Shoulder
2. Glenohumeral Arthritis
3. Labral Tear
4. Massive Rotator Cuff Tear (leaks into the subacromial space)
5. Biceps Tendonitis
6. SLAP tear

Approaches: Anterior or posterior

• generally when blind injection technique used without imaging, anterior approach provides more predictable result than posterior approach (65% vs 46% accurate)
• ALSO, US guided glenohumeral injections vs landmark-guided injections was 92.5% vs 72.5% respectively

Question 399

Which kind of atheltes have an increased propensity to present with suprascapular nerve injury? And what is the mechanism?

Answer 399

• Traction on suprascapular nerve believed to cause symptoms in those who play volleyball or overhead ball-throwing sports such as baseball and team handball
• **N.B. Compressive injuries typically associated with synovial or ganglion cyst

Question 400

Where is the suprascapular nerve most commonly injured? Which muscle(s) would that effect?

Answer 400

This article states that the spinoglenoid notch is the most common location for surprascapular nerve injury, resulting in infraspinatus atrophy.

**The question we have debated is where the nerve is affected for Massive rotator cuff tears - The 2019 consensus is Suprascapular notch but this is a dumb question

Question 401

Name two physical exam signs for biceps pathology. Does ultrasound show better accuracy for injection of the biceps tendon?

Answer 401

1. Palpating of biceps in the groove with pain
2. Speeds test
3. OBrien’s Test (SLAP tear)

None have good sensitivity/specificity

Question 402

What are the three moderate, and one strong recommendation regarding post-knee/hip arthroplasty prophylaxis?

Answer 402

strong: don’t do routine postop duplex u/s
moderate: discontinue antiplatelet agents before
moderate: pharmacologic and/or mechanical VTEp

Moderate: neuraxial anesthesia to help limit blood loss even though it does not affect occurence of VTEp

Question 403

What is the earliest time in which to initiated LMWH postop? How long should the patient be on prophylaxis for?

Answer 403

12 hours postop, to limit postoperative bleeding.

Recommended prophylaxis for 10-14 days for both hip and knee, can be extended to 35 days.

Question 404

List 7 risk factors for VTEs in patients undergoing total hip or knee arthroplasty.

Answer 404

◦Previous VTE

◦Advanced age

◦Obesity

◦Immobilization

◦Estrogen therapy

◦Prolong immobilization

◦Cancer

◦Thrombophilias - antithrombin III deficiency, proteins C abnormalities, protein S abnormalities

◦Molecular risk factories - eg Factor V Leiden, prothrombin 20210A gene mutation, hyperhomocysteinemia

Question 405

Which of the following requires laboratory monitoring postoperatively?

a) ASA
b) Rivaoxaban
c) Warfarin
d) Enoxaparin

Answer 405

C) Warfarin - INR needs to be monitored to ensure therapeutic dose.

Question 406

Which of the following is FALSE. According to the RECORD series of trials, rivaoxaban compared to enoxaparin has been shown to have:

a) decreased rates of symptomatic VTE
b) decreased rates of total VTE
c) increased rates of bleeding
d) decreased rates of death

Answer 406

c) increased rates of bleeding

• RECORD 1
  
  • Rivaoxaban significantly more effective in preventing total VTE
  • Equivalent for rates of symptomatic VTE and major bleeding
• RECORD 2
  
  • Extended rivaoxaband therapy more effective in preventing total VTE and symptomatic VTE
  • Similar rates of bleeding
• RECORD 3
  
  • Rivaoxiban more effective in preventing total VTE and symptomatic VTE
• RECORD 4
  
  • Rivaoxaban superior to enox in preventing total VTE and deaths
  • Similar for symptomatic VTE and deaths

Question 407

List five risk factors for pulmonary embolism in any patient.

Answer 407

1. Anemia
2. Female Sex
3. BMI > 25 (added risk if BMI >30)
4. Age >70
5. Total Knee Replacement
6. Atrial Fibrillation
7. Postop DVT

Question 409

What are 6 secondary ossification centers of the lower extremity?

Answer 409

• GT, ASIS, AIIS, iliac crest, tibial tubercle, calcaneus
• Appear between ages 4 (GT) and 17 (ASIS) and fuse by age 17 (aside from ASIS – 25)

Question 410

• Three most common sites of avulsion fractures in the lower extremity in peds?

Answer 410

1. AIIS
2. Ischial tuberosity
3. ASIS

Question 411

When would you consider surgery for an ischial tuberosity fracture avulsion in peds? and what is the post op protocol?

Answer 411

• Consider surgery for ischial tuberosity avulsion fractures with >2cm displacement
  
  • (Kocher-Langenbeck approach)
  • Post-op protocol is NWB x 6 weeks, then running at 4 months and return to play at 6

Question 412

Which pelvic avulsion fracture is peds can presents with meralgia paresthetica?

Answer 412

• Delayed ASIS avulsion fractures can present with meralgia paresthetica from compression of LFCN
• • • Treatment of ASIS avulsion fractures is essentially non-op (can consider surgery for unremitting pain or displacement >2cm, but very poor evidence)

Question 413

Which pelvic ossificagtion center is the first to appear?

Answer 413

AIIS

Question 414

What other injury is associated with AIIS avulsions?

Answer 414

LAbral tears

Question 415

What are the 3 characteristics of someone affected by bullistic injruies?

Answer 415

1. Male
2. African American
3. Teenager

Question 416

What are the 2 main mechanisms of injury that ballistics have on human tissue?

i.e. How is tissue damage incured from ballistic injuries?

Answer 416

1. Temporary cavity - the energy from the bullet makes temporary cavities
   
   1. Tissues that are more elastic (lung, muscle) have smaller temporary cavity formation
2. Permanent cavity - The energy from the bullet entrance it self creates destruction

Question 417

How are high and low energy gunshot wounds treated different?

Answer 417

• Low-energy gunshot wounds (handgun) don’t cause extensive soft tissue injury, so if the bony injuries meet the parameters for closed management, then the treatment is a bedside I&D and casting
• • High-energy gunshot wounds (rifle) cause extensive soft tissue injury and require aggressive I&D and ORIF if fractures are unstable or are associated with bone loss

Question 418

How are intra-articular gun shot wounds treated?

Answer 418

• Any injury involving a joint should be treated operatively

Question 419

Should antibiotics be given to gunshot wound injuries?

Answer 419

• No clear evidence on antibiotic prophylaxis in the absence of grossly contaminated wounds, but most people would administer them

Question 420

Do ballistic injuries have an effect on the physis even if it’s not directly involved?

Answer 420

Yes - the energy from the bullet can cause physeal injury, especially in high energy gunshot wounds

Question 421

Nervs can be damaged in bullistic wounds - what is the usual injury and how should you treat the different kinds of nerve injuries

Answer 421

• Digital nerves are often pushed out of the way of the projectile and not lacerated, resulting in neuropraxia
• • In cases of nerve injury, if the patient is going to the OR anyway then should explore the nerve and if it’s transected, the ends should be approximated to prevent retraction and definitive treatment is performed 1-3 weeks later to better define the extent of injury. If the nerve is in continuity, then observe for 2 months and refer if no return of function at that point.

Question 422

Spine injuries are most commonly treated non op, but what are 4 reasons to operate?

Answer 422

1. Retained fragments in the disk space (lead toxicity risk) or spinal cord
2. CSF fistulas
3. Epidural hematoma/abscess
4. Instability (rare)

Question 423

What are the symptoms of lead toxicity and how do you treat them?

Answer 423

• Symptoms of lead toxicity: constipation, cramping, seizures, developmental delay, encephalopathy à if blood lead levels >45 µg/dL,
• • Treat with chelation therapy

Question 424

How quickly can you see positive findings of HO on xray?

Answer 424

4 weeks

Question 425

Reagarding HO, how does ALP, bone scan, CT, clinical symptoms and MRI help in diagnosis and management?

Answer 425

• ALP is elevated early and plateaus at 4 weeks (non-specific in fracture patients). But between 2 nd 3 months it normalizes.
• Bone Scan is hot early before any mineralization is seen and is cold at 2-3months.
• CT is helpful for pre op planning
• MRI is NOT helful
• Pain resolves and swelling resolves around 2-3 months

Question 426

What’s incidence of HO after acetabular fracture?

Answer 426

Up to 100%

Question 427

What are 3 general risk factor categories for HO in acetabular fractures?

Answer 427

1. Surgical: approach (iliofemoral > K-L > ilioinguinal), dual approaches, trochanteric osteotomy
2. Soft-tissue injury: debride any necrotic muscle to reduce risk
3. Systemic: male, brain injury, thoracoabdominal trauma, ipsilateral femur fracture, associated sciatic nerve injury, prolonged mechanical ventilation

Question 428

WHat can be used for HO prophylxis in acetabular fractures?

Answer 428

• Postop XRT within 72h (600-800 cGray) à 3% incidence of HO à post op radiation is more effective than NSAIDs.
• Pre op has not shown to be as effective
• • NSAIDs not effective after acetabular fracture surgery (3 RCTs), but it’s still used. But it IS associated with increased risk of non union

Question 429

WHen should you remove HO?

Answer 429

• When HO is causing nerve entrapment leading to neurological symptoms, you shouldn’t wait for maturation to intervene
• • Symptomatic HO should be removed – can get pre op CT to assess location of neurovascular structures and asses the extent of HO. Work from area of known to unknown when removing

**Was previously thought that HO should be fully mature before removing but that is now debated. If at any point there is nerve injury, should interven at that time

Question 430

How doe NSAIDs affect HO production? Through which mechanisms?

How does Radiation affect HO production?

Answer 430

1) Inhibitis upregulation of systemic factors
2) Inhibitis upregulation Local factors

Radiation inhibits recruitment of osteoprognitor cells

Question 431

WHat is the mechanism/pathophysiology of joint contractures?

Answer 431

• With reduced mobility, the number of sarcomeres decreases and cross-sectional area declines = loss of muscle mass and length, but this is reversible within 2 weeks; after 4 weeks, connective tissue also loses its elasticity as adhesions turn into fibrosis à end result is irreversible contracture

Question 432

What is the only non operative preventative strategy that is supported in evidence, to help in reducing joint contractures?

Answer 432

• Static progressive splinting/casting (best evidence is to prevent equinus contractures in patients with head injuries; also useful for patients who develop elbow contractures following brain injury)

Question 433

WHat are the top 7 reasons for revision THA?

Answer 433

1. Instability (22%)
2. Aseptic loosening (20%)
3. Infection (15%)
4. Implant failure (10%)
5. Other mechanical problems
6. Osteolysis (7%)
7. Periprosthetic fracture (6%)

Question 434

WHat is the avg rate wear of HXPE?

And what wear rate increases the risk of osteolysis

Answer 434

• Average wear rate of HXLPE is 0.02mm/y
• Increased risk of osteolysis when poly wear rate > 0.2mm/y

Question 435

WHat are the laboratory indicators that suggest THA infection?

Answer 435

• Evidence of infection: ESR > 30, CRP > 10, > 3000 cells, PMNs >80%

Question 436

How did Beaule define a well fixed acetabular component?

Answer 436

• Beaule defined well-fixed acetabular components as absence of RLL (radioluscent lucency) > 1mm in any 2 zones on AP XR

Question 437

What are 4 ways to measure PE wear for acetabular liners?

Answer 437

1. Dual-circle technique
2. Linear wear
3. Volumetric wear (calculated from the magnitude of linear wear, size of the head and the direction of wear path relative to the face of the cup)
4. Radiostereometric analysis

Question 438

What are the 3 intra op checks to confirm stability when doing a THA?

Answer 438

1. >90^O flexion
2. >45^O IR with the hip flexed to 90^O
3. >15^O ER with the hip extended

Question 439

WHat is the thinnest PE liner you can use in THAs?

Answer 439

4mm IF it’s HXLPE

Question 440

Obesity is a big issue in the US, when doing a TKA on an obese patient, what considerations should you have for compenents?

Answer 440

• Consider stemmed tibial baseplate for class II and III obese patients (increased risk of loosening)
• WHO classes: I (BMI 30-35), II (BMI 35-40), III (BMI > 40); class III = morbid obesity

**They have worse implant survival and is usually on the tibial side which is likley why they recommend stems

Question 441

When doing a TKA in an obese patient, what are some considerations you should have?

Answer 441

• In obese patients, reverse Trendelenburg is the best position from an oxygenation perspective
• • Increased risk of infection, revision and failure of two-stage revision in obese patients
• • No evidence of increased blood loss in obese patients
    *

Question 442

Do obese patients lose weight post TKA?

Answer 442

The evidence says NO

Question 443

Perio-operative pain management in spine surgery can be difficult, what 3 Level 1 evidence recommendations have been made for spine surgery in general?

Answer 443

• Level I evidence supports the routine perioperative use of NSAIDs to improve pain control and reduce opioid consumption for spine surgery, and the use of selective COX-2 inhibitors for short-term, low-dose nonselective NSAIDs does not appear to affect spinal fusion rates, although high-dose nonselective NSAIDs (Ketorolac >120mg/d) may decrease fusion rates
• Level I evidence supports the use of single-dose intrathecal opioid analgesia as an adjunct in pain management after spine surgery
• Level I evidence supports the addition of gabapentin/pregabalin in perioperative pain management for spine surgery
  
  • Gabapentin and pregabalin reduce neuronal excitability by inhibiting presynaptic calcium-gated channels (alpha-2-delta subunit)

Question 444

What evidence is there for tylenol in spine surgery?

Answer 444

• No evidence for acetaminophen use in spine surgery, but generally it’s used since it’s shown in so many other places that it helps diminish perioperative opioid requirements

Question 446

What are the spine manifestations ofr OI?

Answer 446

scoliosis, kyphosis, basilar invagination, lumbar spondylolisthesis

Question 447

What is the main typo of collagen affected in OI patients and what can OI patients have as a result?

Answer 447

• Type I collagen
• It is found in bone, ligaments, dentin and sclerae -
• Associated features are:
  
  • fragility fractures, short stature, joint hypermobility, dentinogenesis imperfecta, blue sclerae, early hearing loss

Question 448

Bisphosphonates play a role in OI treatment, what effects do they have?

Answer 448

• Bisphosphonates (Pamidronate) have positive effects on vertebral morphology, bone density and fracture rate without any major side-effects, so they’re started in infancy for patients with type III or IV OI (and sometimes more severe forms of type I)

Question 449

In Type III OI, when should bisphosphonates be started? And how should they be managed post PSF?

Answer 449

• Bisphosphonates given before age 6 in type III OI slows scoliosis progression
• No evidence for this but recommendation is to hold for 4 months post-PSIF to allow for osteoclast function to remodel fusion mass

Question 450

What are 3 features of scoliosis in OI? and what is thought to be the cause of scoliosis in OI patients?

Answer 450

• Scoliosis features in OI:
  
  • Usually present after age 6
  • Rapidly-progressive (correlates with lower Z-score and 6 or more biconcave vertebrae)
  • Single thoracic curves most commonly (almost 100% for type I and 60% for type III)
• • Etiology of scoliosis in OI: secondary to vertebral fractures

Question 451

Does bracing work in OI patients for scoliosis?

Answer 451

No

Question 452

At what angle should you consider surgical treatment in OI patient with scoliosis? And what 2 considerations should you have when fusing the spine?

Answer 452

• Fuse when >45^O
• • Improved outcomes with pedicle screws with cement augmentation at the proximal and distal screws (48% curve correction with no loss of correction at follow-up)
• • Difficult exposure of thoracic spine due to rib overgrowth and thoracic lordosis - Ponte and rib osteotomies may be required
    *

Question 453

what are 4 symptoms of basilar invagination?

Answer 453

1. Headaches (hydrocephalus),
2. Cranial nerve palsy,
3. dysphagia,
4. myelopathy

Question 454

What are the indications for surgical management in basilar invagination in OI patients?

Answer 454

• Dens tip above McRae’s line,
• >5mm above Chamberlain’s or
• >7mm above McGregor’s lines

Question 455

Basilar invagination can occur in OI patients, what % can reduce with intra op traction vs those who do not? and how do you manage both circumstances?

Answer 455

1. 40% reduce with intra-operative traction and posterior decompression,
   
   1. Tx: occipitocervical fusion usually to C7, T1 or T2 (+/- instrumentation with sublaminar wiring), Halo vest until union
2. 60% do not reduce with traction
   
   1. Tx: Usually require a staged approach – transoral decompression, then occiput-C2 fusion 1 week later, Halo vest until union

Question 456

OI patients require special anesthetic considerations, please name 5

Answer 456

• Gentle transfer to operating table (fracture risk)
• In type III and IV, avoid tourniquet (fracture risk)
• Difficult airway (large head, short neck)
• Avoid succinylcholine (fasciculations are a fracture risk)
• Increased risk of bleeding (controlled hypotension, TEXA)

Question 457

when do the majority of relapses occur with clubfoot?

Answer 457

Within the first 5 years

Question 458

What are 4 signs/risk factors for relapse in clubfoot?

Answer 458

1. Drop toe sign (no toe extension with plantar stimulation – indicative of absent function of anterior/lateral compartments)
2. Flexion contracture of wrist and fingers (sign of distal arthrogryposis)
3. Spinal dysraphism
4. Noncompliance with foot abduction orthosis (compliance decreases from 91% in the first month to 77% in third month)

Question 459

When doing boots and bars for clubfeet, how do you position the feet in bilateral patients? unilateral patients? and until what age do they wear the boots and bars?

Answer 459

• For bilateral deformity, the FAO positions the feet in 60-70^O abduction, 5-10^O dorsiflexion
• For unilateral deformity, the uninvolved foot is positioned in 40^O abduction
• Night-time brace until age 3-4

Question 460

What is the earliest sign of relapse in a patient treated for clubfoot?

Answer 460

• Earliest sign of relapse is less dorsiflexion than the previous examination

Question 461

At what point do you restart ponsetti casting in a patient with recurrence? i.e. what physical exam sign pushes you to restart ponsetti casting?

Answer 461

• If unable to dorsiflex >10^O but flexible deformity, start treatment of relapse

Question 462

When a patient with clubfoot relapses, what algorithm do you follow?

Answer 462

1. Repeat Ponsetti casting for 3 sessions, 1 week apart
2. Repeat Achilles tenotomy if <15O dorsiflexion after casting
3. Full-time FAO use if <2 ½ yo; 12-14 hours a day if >2 ½ yo
4. Consider ATTT if >2 ½ yo (by this stage, enough ossification has occurred in the lateral cuneiform to allow for bone-tendon healing) – still need to regain correction of foot via casting before transfer. But benefit is that ATTT prevents the nee for FAO
5. Transfer the whole AT tendon – do NOT split
6. If ATTT is done, no need to further brace due to everting force of pull of the tibialis anterior

Question 463

In a clubfoot patient with relapse but also has a rigid foot, what are 3 treatment options?

Answer 463

• If deformity is rigid and patient is older, then osteotomies +/- releases are needed:
  
  1. Forefoot adduction - lateral cuboid closing wedge, medial cuneiform opening wedge osteotomies
  2. Posteromedial release: principles are release circumferentially tight capsules (posterior ankle, subtalar, TN) and ligaments (superficial deltoid) and lengthen tight tendons (tib post, FDL, FHL)
  3. Ilizarov for crazy deformities that need to be staged (multiple osteotomies, releases)

Question 464

Skeletally immature patients can be difficult to treat when they require reconsruction post tumor resection. What are your reconstruction options based on LLD?

Answer 464

• Estimated LLD at skeletal maturity:
  
  • <2 cm, no need to do anything
  • 2-5 cm à contralateral epiphysiodesis at the appropriate time
  • >5 cm à extendible prosthesis, secondary limb lengthening, rotationplasty

Question 465

In pediatric patients wwith diaphyseal tumors, what are your reconstruction options? And risks associated with each?

Answer 465

• <10 cm of bones loss: intercalary allograft with either nail or locked plate fixation, bone transport
  
  • Non-union with locked vs. non-locked plates (25% vs. 45%)
  • Often, the initial fixation crosses the physis, but the epiphyseal screws in the locking plate can be removed after bony union
• >10 cm à vascularized fibula (90% union rate)
  
  • Risks:
    
    1. Peroneal nerve injury
    2. Claw toes (FHL)
    3. Syndesmotic instability (for very distal harvests, consider doing distal tibiofibular synostosis)
    4. Late ankle valgus deformity (from distal tibial growth arrest due to supraphysiologic loads)

Question 466

In skeletally immature tumor patients who require transphyseal amputation due to extension from the metaphysis, how should you reconstruct the limb?

Answer 466

• Even if the physis needs to be resected, it’s still worth preserving the articular surface and reconstructing as per diaphyseal resections (<10cm vs >10cm )
• Should do these cuts either with patient-specific guides or intra-operative navigation due to low margin for error

Question 467

If an intr-articular resection is required in skeletally immature tumor patients, what are 2 reconstruction options? and what are the pros and cons?

Answer 467

1. Osteoarticular allograft (proximal tibia is a common one)
   
   • Pros: avoids stemmed implant across the knee, restores bone stock
   • Cons: low graft availability, graft remains necrotic, infection, fracture*, instability

*Consider intra-medullary cement in the allograft to decrease risk of fracture

• 72% rate of conversion to allograft-prosthetic composite

1. Endoprosthetic reconstruction (gold standard)
   
   • Cemented (immediate weight-bearing)
   • Uncemented (delayed weight-bearing due to slow rate of bony ingrowth while patient undergoes adjuvant chemo)

Question 468

If a child needs amputation, what is the change in energy expensidture with Syme vs AKA?

Answer 468

• Syme = 15% increased energy expenditure
• AKA = 50% increased energy expenditure

Question 469

What is the rate of bony overgrowth post amputation in kids? and what are 2 risk factors?

Answer 469

Overgrowth following amputation occurs in up to 40% of kids

• Risk Factors:
  
  • ​<10 yo,
  • humeral diaphysis,
  • tibial diaphysis

Question 470

What is the only structure that needs to be left intact if doing a rotationplasty?

And how do the QOL scores compar to general popultion?

Answer 470

• Only structure that needs to be left intact for success of a rotationplasty is Sciatic nerve and its branches (can resect/anastomose vessels if necessary to achieve margins)
  
  • Quality of life scores nearly equivalent to the general population
  • Relational and emotional difficulties in high-school which are overcome by adulthood

Question 471

WHat are 4 pre-op strategies to help make definitive management easier in peds patients with large stiff spines?

Answer 471

• Options include:
  
  1. Halo gravity traction
  2. Halo-femoral traction
  3. Temporary internal distraction
  4. Anterior-posterior combined approaches

Question 472

What is the 1 indication to halo gravity traction and the 3 contraindications

Answer 472

• Indications: >70^O curves that correct <20% with side-bend
• Contraindications:
  
  1. <18 mo (pin penetration into skull)
  2. Short, sharp, rigid curve
  3. C-spine instability

Question 473

What is a protocol for Halo gravity traction regarding adding weight ?

Answer 473

• Start with 5lbs and add 2lbs each day until 50% body weight is reached, then maintain maximal traction for 2 weeks

Question 474

One study looked at Halo gravity traction vs no gravity traction, what were the outcomes?

Answer 474

• No difference in complications, surgical time, blood loss and ultimate Cobb angle after surgery between those treated with/without HGT prior to fusion
• The HGT group had a lower incidence of required vertebral column resection

Question 475

What are the 6 possible complications associated with Halo gravity traction in kids?

Answer 475

1. Pin-site infection and loosening
   
   • Proper pin placement: four anteriorly (1 cm superior to lateral eye brow) and four posteriorly (1 cm superior and posterior to the pinnae) with 2 cm of space between the halo ring and the head
2. Nerve palsies (CN VI most commonly and due to traction – loss of lateral gaze)
   
   • Treat by reducing traction until they resolve, then gradually increase again
   • All resolve
3. Brachial plexus palsy
4. Skull penetration
5. SMA syndrome
6. Odontoid AVN

Question 476

What are the 3 time points when xrays should be done when treating a child with halo gravity traction?

Answer 476

• • Pre-initiation of treatment
    
    • At 50% body weight of traction
    • Immediately pre-operatively

Question 477

What are 2 alternative treatments to halo gravity traction in a peds patient with a stiff large curve?

Answer 477

1. Halo-femoral traction:
   
   • Requires bedrest until surgery (whereas HGT can be used with wheelchairs for mobility) – increased risk of complications
   • Otherwise, same principles and complications as HGT
   • May be helpful intraoperatively when there’s a significant pelvic obliquity
2. Temporary internal distraction:
   
   • Consider when HGT is contraindicated
   • Sublaminar or subpedicle hooks proximally, supralaminar hooks or pedicle screws distally at the two most proximal and distal levels that will be used for the definitive fusion and intraoperative distraction
   • Timing: 1 week (no benefit after that)

Question 478

How do you do an anterior release for a large stiff peds scoliosis? and what are 5 complications?

Answer 478

• Apex is approached from the convex side and the ALL, discs and endplates are excised (250^O) arc of release
• Can place bone graft in the disc spaces for fusion
• Complications:
  
  1. Increased surgical time/blood loss
  2. Pneumonia
  3. Prolonged intubation
  4. Coagulopathy
  5. Hypotension requiring vasopressors

Question 479

What have studies shown when comparing posterior only vs ANterior + posterior fusion for peds patients with large stiff curves?

Answer 479

• Multiple recent studies show no difference vs. posterior-only approach since pedicle screws are much stronger than previously-used fixation methods and can achieve huge amounts of correction

Question 480

8 physiologic changes in a pregnant patient

Answer 480

1. Increased SI/PS distance
2. Increased blood volume
3. Increased WBC and RBC mass
4. Increased minute ventilation
5. Decreased Functional residual lung volume
6. Decrease BP
7. Decreased GI motility
8. Decreased esoph sphincter competency

Question 481

Which trimester of pregnancy has the worst degree of transient osteoporosis?

Answer 481

• Transient osteoporosis occurs during pregnancy, especially during third trimester when much of the calcification of the fetus is happening 

  
  • If not taking supplemental calcium, increased risk of fractures. 

  • osteoporosis resolves on its own a few months post partum 


Question 482

What additional blood work do you need to draw during ATLS for a pregnant patient?

Answer 482

• Always need to draw bHCG if female 

  
  • if concern for fetal-maternal hemorrhage need to test blood for Rh antigen (+ or -

Other considerations:

• spine board inclined 15degrees to left to reduce IVC compression
• Fetal heart rate monitoring

Question 483

Factors associated with adverse fetal outcomes in trauma of a pregnant patient (5)

Answer 483

1. high ISS
2. low GCS
3. Low hgb level
4. development of DIC
5. Length of hospital stay

Question 484

What is the max cumulative radiation dose afforded to a fetus?

Answer 484

Max cummulative dose to a fetus is 5rad (50 mGy)

Question 485

3 categories of adverse effects of irradiation in fetuses

Answer 485

1. Teratogenesis (fetal malformation resulting in CNS changes; mental retardation, microcephaly. Linear relationship with radiation dose.)
2. Carcinogenesis (Induced malignancy)
3. Mutagenesis (alteration of germline genes)

***Weeks 3-15 are greatest risk for teratogenesis**

Question 486

What period of fetal development are fetuses at greatest risk fo teratogens is from radiation?

Answer 486

***Weeks 3-15 are greatest risk for teratogenesis**

Question 487

Which anticoagulant is safe to use in a pregnant patient?

Answer 487

LMWH has replaced UFH – does not cross the placenta, do not require monitoring, have better schedule, and less risk of osteoporosis

Other facts:

• Pregnant patients have 5X DVT risk due to hypercoagulable state.
• Use ICDs

Question 488

Should you CT a pregnant trauma patient?

Answer 488

• Higher dose but “CT should not be withheld if it is indicated clincially”
  
  • Important for uterine rupture, placental separation, fractures

Limit slice width and number of cuts as possible

Question 489

Techniques to decrease intraoperative radiation exposure of pregnant patients.

Answer 489

• Shield fetus at all times (from all directions)
• Use surgical technique to minimize femoral/pelvic xrays
  
  • Limit preop imaging
  • MRI
  • Careful preop planning

Question 490

Intraop considerations in pregnant patients (3)

Answer 490

• Left lateral decubitus (or if on spine precautions, wedge under patient, tilt the bed)
• MAP > 65 for placental flow
• For Bogdan: If it’s a left calc, non op! They all do miserably anyways.
• Plating often has less fluoro than nails/perc plating so keep those options in mind

Question 491

Indications for surgical management of pelvic #s (5) in pregnant patients

Answer 491

1. Open pubic symphysis rupture secondary to severe vaginal tearing
2. Diastasis of the symphysis of >3cm
3. Substantial malreduction of the pelvis
4. Diastasis with pelvic binder in place
5. Displacement of one or both of the SI joints

Question 492

How soon after a pelvic ring injury can a pregnant patient deliver vaginally?

Answer 492

• Depends on if fractures have healed – 6-8weeks, then can still do vag
• If concerned, displaced, c section should be considered.

Question 493

How much retroversion is there of the native proximal humerus?

Answer 493

Mean Retroversion 18-25deg, range 5 ante to 60 retro

Question 494

In which direction is the Humeral canal offset from the centre of the humeral head?

Answer 494

The humeral head COR is Offset from the canal medially by 5-11mm, and posteriorly 1-5mm

Question 495

Technical things to avoid when sizing TSA components

Answer 495

• Important to reproduce for cuff
• Excessive thickness can overtension the cuff, increase contact pressures, and lose ROM.
• Insufficient thickness can result in undertensioning and weakness of the cuff, excess translation of the HH, prosthesis instability, glenoid failure.

Overstuffing = decreased translation and decreased ROM à leads to increased glenoid stress, accelerated glenoid loosening, RC failure

Question 496

Which is better, press fit of cemented humeral stems in TSA?

Answer 496

• Same axial micromotion
• Rotational micromotion - Press fit > cement

Question 497

Benefits of cemented humerus in shoulder arthroplasty (4)

Disadvantages (2)

Answer 497

1. Benefits:

• Overcome mismatch of implant fit
• Smaller implant so less stress shielding
• Decreased intraop #
• Don’t rely on in/on-growth if compromised bone

1. Disadvantages:
   
   1. Longer OR time
   2. Difficult revision

Question 498

Benefits of short stemmed/stemmless humeral head implants in TSA

Answer 498

• Advantages:
  
  • Lower risk of PeriP #
  • Preserve PH bone stock

Question 499

How does rTSA change the centre of rotation of the shoulder?

Answer 499

Moves it medially and inferiorly

Question 500

In TSA, what happens if you:

A) increase retroversion?

B) Increase anteversion?

Answer 500

• Inc Retroversion – inc ER, dec IR
• Inc Anteversion – Dec ER, inc posterior notching
• Retroversion of 20-40deg best restores functional ROM

Question 501

Indications for deinnervation of the wrist (3)

Answer 501

• Skeletally mature (no upper age limit)
• Chronic wrist pain (>6mos)
• Refractory to non-surgical management

Question 502

Contraindications to wrist deinnervation.

absolute (4)

relative (5)

Answer 502

• Absolute:
  
  • Active infection
  • Cognitive impairment
  • Poor compliance
  • Acute/chronic conditions that can be managed nonoperatively
• Relative:
  
  • Diffuse arthritis
  • Unrealistic patient expectations
  • Severe instability
  • Posttraumatic incongruity
  • Patient desire for more definitive procedure (ie arthrodesis)

Question 503

What is deinnervated in a Wrist deinnervation?

Answer 503

• Complete/Total
  
  • Up to 10 articular nerve branches
• Partial denervation
  
  • AIN and PIN
  • AIN alone
  • PIN alone – deterioration over time

Question 504

Where is teh AIN located at the wrist?

Answer 504

• between IOM and deep head of PQ
• usually is ulnar to PIN and radial to anterior interosseous artery

Other facts

• 2-3x size of PIN
• Final motor branch (to PQ) branches off approx 2cm prox of the ulnar head
• Resect 1cm segment of the AIN distal to the last motor branch

Question 505

What is a good prognostic factor for outcomes of wrist deinnervation?

Answer 505

• High negative predictive value if no pain relief with analgesic block, i.e. denervation may not be effective
• Pain relief post injection carries a good prognosis

Question 506

Complications of wrist deinnervation

Answer 506

• Sensory disturbance due to retraction
• Tinel sign (May persist up to 6 mos)

Question 507

WHat are the landmarks and technique for doing an anterior GH injection?

Answer 507

• Palpate the coracoid, soft spot is superior and lateral to this which is the rotator cuff interval - this is the ideal location for needle insertion.
• when you insert the needle and hit bone, gently rotate the arm to see if there is movement. If no movement, then you are on glenoid so move laterally. If you feel movement, then move medially
• when you are in the joint, stop rotating and inject