Scott Oral Exam Prep

Question 1

Outline your algorithm for dealing with neuromonitoring changes.

Answer 1

Gain control of the room

Pause case, announce to room

Remove distractions (music, etc)

Summon staff anesthetist, neurophysiologist, nurse.

Anticipate need for imaging.

Systemic/Anesthetic

Optimize MAP, Hb, pH, CO2, Temperature

Discuss potential need for wake up test

Technical

Verify anesthetic agent; presence of paralysis

Check electrodes & connections

Patient positioning

Timing and pattern of signal changes

Surgical

Remove traction, rods, screws

Probe screw holes PRN

Check osteotomy/laminotomy sites for compression

Imaging to confirm implant position

Ongoing

Wake up test if signals not improved

Reassess anesthetic/systemic issues

IV methylprednisolone 30mg/kg first hr, then 5.4 mg/kg/hr for 23 hrs.

MRI or CT myelogram

Consult with a colleague

Consider staging procedure. If spine unstable, remove any concerning screws, leave rods and spine in uncorrected position.

Question 2

List three instances where one need not repair a dural tear.

Outline the postop protocol for a dural tear not repaired.

Answer 2

1. Dura torn but arachnoid membrane intact
2. Non repairable due to minimally invasive technique
3. Anterior/inaccessible location

Bed rest 48 hrs then stand up test.

OK? Then get MRI at 6 mos

Headache? One more day of bed rest.

Consider return to OR for repair if still no better.

Question 3

Outline intraop management of dural tear

Answer 3

RISK FACTORS: Revision surgery, OPLL, surgeon inexperience, connective tissue disorder, older patient

Visualization

Position in reverse Trendelenburg

Lighting/headlight/loupes

Decompress more bone PRN

Suction with cotton pledget

Hemostasis (bipolar; fibrin glue; gelfoam; surgicel)

Repair

Ensure no rootlets extruded

4-0 or 5-0 nylon running closure of dura (watertight)

Fibrin glue sealant

Valsalva to test integrity of repair.

Patch if not repairable (lumbodorsal fascia or fascia lata patch)

Watertight closure in layers.

Consider subfascial drain if valsalva causes leakage

Postop

Antibiotics for duration of drain

Bedrest for 48-72 hrs (Standup test)

Persistent drainage? Get IR or NSx to insert subarachnoid lumbar drain above durotomy. No more than 400 cc per day (clamp if >400cc in 24hrs)

Remove drain at 48 hrs.

Question 4

Differential Diagnosis of bone lesion in children <5

Answer 4

Benign

Osteofibrous dysplasia

Osteomyelitis

LCH

Malignant

Leukemia

Metastatic rhabdomyosarcoma

Metastatic neuroblastoma

Question 5

Differential for bone lesions in patients <30

Answer 5

Benign

LCH, Fibrous dysplasia, osteofibrous dysplasia, osteoid osteoma, osteoblastoma, chondroblastoma, UBC, ABC, NOF, Osteomyelitis

Malignant

Ewing’s, Osteosarcoma, Leukemia

Question 6

Differential for bone lesions in patients >30

Answer 6

Benign

GCT, Brown’s tumour (hyperPTH), Paget’s

Malignant

Mets, Multiple myeloma, Lymphoma, Chondrosarcoma, Chordoma,

Paget’s and postXRT sarcoma

Question 7

List principles of biopsy

Answer 7

Preop:

Have pathologist available

Labs (CBC, plts, INR)

Do in definitive treatment centre

Intraop:

Tourniquet on, don’t inflate

Longitudinal/extensile incision which can be incorporated into definitive resection

Meticulous hemostasis

Avoid creating/dissecting planes

Avoid neurovascular structures

Biopsy through single muscle compartment

Biopsy the soft tissue mass if possible

Bone biopsy - oval window

Send tissue for both frozen AND culture/sensitivity

If using drain, bring out in line w/ incision

Question 8

Differential Diagnosis for multiple bone lesions

List benign/malignant

Answer 8

Benign:

Polyostotic FD, LCH, Multiple enchondromatosis, Multiple exostoses, Brown tumour, Paget’s, multifocal osteomyelitis

Malignant:

Mets, Multiple myeloma, Multifocal osteosarc

Question 9

DDx for lesions in the sacrum

Answer 9

Midline:

Chordoma

Eccentric:

ABC, GCT, Mets, Chondrosarcoma

(Recall: Chordoma is S100 and keratin positive)

Question 10

Investigations for metastatic disease

Answer 10

Prostate PSA

Thyroid U/S

Breast Mammogram

Lung CXR or CT Chest

Kidney CT abdo

MM SPEP/UPEP/Skeletal survey

Lymphoma CT C/A/P

Question 11

Dr Holt mnemonic for diaphyseal lesions Ddx

Answer 11

A: adamatinoma

E: Eosinophilic Granuloma

I: Infection (osteomyelitis)

O: OO or OB

U: Ewing’s

Y: Myeloma, Lymphoma, Fibrous dYsplasia

METS

Question 12

List 4 tumours treated with wide resection alone.

Answer 12

Chondrosarcoma

Chordoma

Parosteal Osteosarcoma

Adamantinoma

Question 13

Benefits of gadolinium enhancement of MRI

Answer 13

Abscess will show peripheral enhancement

Can identify cystic/necrotic areas of a tumour

Pattern of enhancement can suggest benign vs malignant lesion

Pattern of enhancement can identify aggressiveness of vascular/lipomatous lesions

Question 14

Outline your follow up plan for Soft Tissue Sarcomas

Answer 14

Visits q 3mos for a year

q 6 mos for 5 years

then yearly until 10 years

Physical exam and CXR at each visit

Question 15

Lesions treated with chemotherapy and wide resection

Answer 15

Osteosarcoma

Periosteal osteosarcoma

Ewing’s Sarcoma

MFH of bone (fibrosarcoma)

Dedifferentiated Chondrosarcoma

Mesenchymal Chondrosarcoma

Rhabdomyosarcoma

Synovial Sarcoma

Question 16

Describe 2 techniques for hip arthrodesis

Answer 16

1. Watson Jones, anterior capsulotomy to denude cartilage, take off vastus lateralis, fix with 150 degree DHS and a few large cancellous screws. Postop spica.
2. Smith Pete (modified). TFL/Sartorius plane. Watch for LFCN. Need to detach sartorius off ASIS and rectus of AIIS. Modification includes elevation of the abdominal muscles off the crest to subperiosteally expose the inner table (elevate iliacus) back to the SI joint. Femoral exposure is done by lifting vastus lateralis off from lateral to medial (to protect innervation). Must tie off ascending LFCA. Anterior capsulotomy (T) to denude cartilage. Insert a single lateral lag screw across the joint into superior acetabulum. Then a 12-14 hole large frag plate precontoured. Plate starts just lateral to SI joint to get good screws in PSIS bone. Contour to pelvic brim and down the femur. Can use compression device.

Position: 20-30 flexion, 0-5 adduction, 0-10 of ER

Costs 30% more energy expenditure

Question 17

3 techniques for knee arthrodesis

Answer 17

Positions is 5-8 of valgus, 0-20 of flexion, and ER to match the other side (check preop).

1. Retrograde/antegrade short nail (ie Wichita)

Benefits of less blood loss, no fem/tib mismatch and less breakage. Standard anterior approach and prep of surfaces. Ream and size tibia first (will be limiting size as tibia is smaller). Lock prox and distal with jig, compression with wrench. Bone graft PRN. Don’t incorporate patella if you plan to revise to TKR later. Zimmer/cast for 6/52. I will WBAT.

2. Long antegrade nail (piriformis start)
3. Dual compression plating. Options are medial/lateral or medial/anterior. Large frag contoured plates. 4 screws above and below.

Question 18

4 ways to assess for normal joint line position in revision TKR

Answer 18

2 finger breadths above tibial tubercle

15mm above fibular head

3cm distal to medial femoral epicondyle

Look for old residual meniscus rim during surgery

**Just get an xray of the other side to compare. Note the height of the joint line above the fibular head**

Question 19

6 intraop considerations for revision TKR

Answer 19

Exposure (and need for snip, turndown, osteotomy etc)

Safe removal of components

Addressing bone loss defects

Fixation of new revision components

Restoration of joint line

Balance of ligaments (and extra constraint PRN)

Question 20

SONK vs secondary osteonecrosis of knee?

Answer 20

SONK

Older patient (>55), usually female

Usually unilateral medial femoral condyle

Tx: Nonop, then UKA or TKA if fails to respond

Spontaneous osteonecrosis

Younger (age <55), usually female, 80% bilateral

Risk factors often present

Pain when going from sit to stand

Tx: Nonop, vs allograft vs arthroplasty

Question 21

DDx for painful THA with positive xray findings

(ie things that can be seen on xray)

Answer 21

Aseptic loosening

Septic loosening

Osteolysis without loosening

Micromotion

HO

Stress shielding

Question 22

DDx for painful THA with negative xray

Answer 22

Reactive synovitis

ALVAL or Pseudotumour

Metal Hypersensitivity

Prosthesis impingement

Iliopsoas irritation

Gluteus medius tear

Nerve injury

GT bursitis

Inguinal hernia

Referred pain (intrapelvic or L spine)

Question 23

What is the Dorr ratio?

Answer 23

Dorr calcar to canal ratio. Used to determine whether uncemented femoral component is appropriate.

Measure canal width at midpoint of LT, then 10cm distal.

A: <0.5

B: 0.5-0.75

C: >0.75 (AKA stovepipe)

Question 24

How to identify the anatomic hip centre?

Answer 24

Ranawat’s Triangle

Measure pelvic height (horizontal lines at top and bottom of pelvis)

Draw vertical line thru a point “A” 5mm LATERAL (yes) to the intersection of Kohler’s and Shenton’s lines.

Draw another perpendicular line above “A” 20% of pelvic height. The length of this line should also be 20% of pelvic height.

Connect the triangle. Hip centre is the middle of the hypoteneuse.

Question 25

Issues to mention for DDH arthroplasty.

Answer 25

_Acetabulum_ Soft bone; restore hip centre; smaller component; try for \>50% host coverage; alternate bearing surface _Femur_ Smaller canal, modular components for version; don't over lengthen; posterior GT location

Question 26

Equipment to ask for in DDH hip case

Answer 26

Smaller components (DDH components) Modularity Alternate bearing surfaces Intraop xray Structural allograft or augments Consider TM shell or cluster shell for screws Fixation for subtroch osteotomy (cables)

Question 27

Describe interval for Ludloff approach

Answer 27

Superficial Between gracilis and adductor longus (both supplied by anterior division of obturator nerve) Deep Between adductor brevis (anterior division of obturator nerve) and adductor magnus (dual innervation by posterior division of obturator and tibial nerve)

Question 28

Pros/Cons of different bearing surfaces. Metal on Poly Ceramic on ceramic Metal on Metal

Answer 28

_MoP_ Lowest cost, long track record, most options Highest risk of particle induced osteolysis, higher wear rate _CoC_ Lowest wear rate, inert particles High cost, risk squeaking, risk of fracture (brittle), fewer options for size _MoM_ Low wear rate, large head size allows for inc ROM Metal debris/reaction/sensitivity, bad for CRF/child bearing females, higher cost.

Question 29

Arthroplasty issues specific to Paget's disease

Answer 29

_Preop_: Treat with bisphosphonate first Anesthesia: high output cardiac failure Make sure to rule out Paget sarcoma ``` _Intraop_: Blood loss (be prepared) ``` Deformity (may need osteotomy, cemented fixation) Protrusio (in situ neck cut, medial bone graft) _Postop_: HO prophylaxis

Question 30

Structures at risk with acetabular screw placement (by quadrant)

Answer 30

_Posterosuperior_ (max screw length 45mm) Sup gluteal nerve/artery Sciatic _Posteroinferior_ (max screw length 20mm) Inf gluteal nerve/artery, internal pudendal artery _Anterosuperior_ External iliac vessels _Anteroinferior_ Obturator vessels

Question 31

Zones of loosening THA

Answer 31

_Acetabulum_ Charnley zones (1: sup 1/3; 2: middle 1/3; 3: inferior 1/3) _Stem_ Gruen zones AP 1-7 (1 is GT, 4 is tip, 7 is LT) Lateral 8-14 (8 is anterosup, 14 is posterosup)

Question 32

Stuff to request for revision hip

Answer 32

_Acetabulum_ Cement, cancellous graft, structural graft, TM shell, cluster shell, explant, intraop xray, curets, reamers, have cage and constrained liner nearby PRN _Stem_ Osteotomes (rigid and flexible), flexible reamers, curets, trephine reamers, revision stem, modularity, cables/grip plate, strut graft, bearing surface of choice, high speed burr

Question 33

Outline technique of foot fasciotomies

Answer 33

Medial incision 6cm incision below MM heading to base of 1st MT. stay 3cm above the sole. Open medial compartment (abd hall), calcaneal cmpt (quadratus plantae - beware lateral plantar Baxter's neurovasc bundle), superficial cmpt (FDB), adductor cmpt, and lateral cmpt (FDMB and AbDB). Dorsal incisions (2) 1. Over 2nd MT - open 1st and 2nd interosseous compartments 2. Over 4th MT - open 3rd and 4th interosseous compartments.

Question 34

Algorithm for adult flat foot

Answer 34

1. Immobilize vs tenosynovectomy 2A: FDL to navicular, medial calc slide, possibly TAL 2B: Same with evans calc lateral lengthening \*\* Forefoot supinated? If medial column stable do Cotton osteotomy (dorsal opening wedge of medial cuneiform). If medial column lax to 1st TMT fusion 3: (Subtalar OA) Do triple fusion (or double fusion nowadays, TN and ST fusion) with TAL 4: Valgus ankle with talar tilt. If correctable can do double fusion with deltoid reconstruction and TAL. If rigid, do TTC fusion (and TN fusion if affected)

Question 35

Algorithm for cavovarus foot

Answer 35

Flexible Plantar fascia release, 1st ray DF osteotomy, TAL, Peroneus longus to brevis transfer Rigid Above plus calcaneal osteotomy. Either lateralizing slide or Dwyer lateral closing wedge (If severe can do Triple Fusion)

Question 36

Malalignment cutoffs for selecting ankle arthroplasty?

Answer 36

20 of varus 10 of valgus

Question 37

Simple AP and lateral radiographic evaluation of angular deformity may not correctly define the exact plane of angular deformity. When angular deformity is present on both the AP and lateral, the true plane lies somewhere in between, and the magnitude is greater than that seen on either the AP or lateral. List a simplified techique of finding the true plane of angular deformity.

Answer 37

Using fluoro, rotate the limb until you find the plane where no angular deformity is present. Your plane of maximal deformity will be perpendicular to this fluoroscopic plane. Take xrays in this orthogonal plane to define the true magnitude of the deformity.

Question 38

What do growth recovery lines (Harris lines) tell you?

Answer 38

Lines parallel to the physis indicate normal growth. Lines will converge towards a problem area of the physis.

Question 39

Pearls for resection of physeal bridge/bar

Answer 39

Direct approach for peripheral vs metaphyseal window/wedge/osteotomy for central Excise the periosteum at approach site. Don't remove more periosteum than is necessary. Don't disrupt the perichondral ring. High speed burr to resect the bony bridge, plenty of irrigation & suction. Resect a couple millimeters of the metaphysis and epiphysis on either side of the bridge. Visualize normal white (bluish) physis around the entire defect, can use a dental mirror. Interposition material (either fat of PMMA). Can suture the fat graft thru drill holes to prevent migration. DON'T close the periosteum around the defect (can cause peripheral bridge re-formation)

Question 40

Indications for surgical management of physeal bar

Answer 40

Less than or equal to 50% of physeal area involved 2 yrs or 2cm growth remaining. \*\*Except\*\* Distal radius arrest - consider treating if \>2mm growth remains because risk of overloading the distal ulna.

Question 41

Anterolateral bowing algorithm

Answer 41

_Bowing without fracture_ Pre-walking: Educate parents Post-walking: KAFO brace until maturity or until # McFarland procedure: Fibular allograft "bypass" strut inserted into concavity of tibia. Rarely done. _Fracture treatment_ In young kids can still treat in KAFO Treat pseudarthrosis with _aggressive_ takedown, tibial shortening, crest bone grafting and IM fixation (no minimum age!). Consider BMP2. Spica 6-8 weeks then long leg cast for 1-2 more mos Principles are to protect the whole bone. Female end across talus/calcaneus under age 5. Across talus only from ages 5-8. K wire to protect the fibula. Other options: Ultrasound stimulation, ipsilateral vascularized fibula. Last resort: Syme's amputation (tibial pseudarthrosis stabilized by prosthetic socket) _Risks_: Refracture (need to exchange for longer rod until maturity) Ankle valgus (tx with medial physeal stapling) LLD (prevent by arresting contralateral leg)

Question 42

Outline forequarter amputation

Answer 42

Anterior incision starts 2cm lateral to SC joint. Superior limb over the AC joint, inferior limb beneath axillary hair. Posterior limb behind shoulder. _Anterior work_ Release clavicular head of pec major. Osteotomize clavicle lateral to SCM insertion. Release muscles off clavicle. Double ligate and divide subclavian vessels and plexus (traction). Release Pec major and Lat Dorsi off the humerus. Release muscles off coracoid process. _Posterior work_ Release skin flap off AC joint, acromion and superficial surface of scapula. Release musculature off scapula (trapezius, omohyoid, levator, rhomboids, serratus). Arm is now free. Suture pec, lats, traps, serratus over the chest wall. Trim skin flaps. Close over a drain.

Question 43

Outline posterior flap external hemipelvectomy.

Answer 43

Position semi-supine with roll under side of trunk to prop up the patient. _Anterior_ Incise along crest and along inguinal region to the symphysis. Sharply release abdominal musculature the whole way from PSIS to ASIS and on to symphysis. Protect spermatic cord/round ligament. Develop retroperitoneal approach back to the SI joint. Double ligate common iliac vessels. Ligate femoral nerve. Divide psoas muscle above the pelvis. _Perineal_ Assistant abducts and flexes the leg. Continue incision from symphysis along the ischium. Disarticulate the symphysis. Protect bladder and urethra with malleable retractor. Develop ischiorectal space. _Posterior_ (may need to place patient in lateral position) Skin incision continues laterally along gluteal crease and then heads anteriorly and superiorly to the ASIS. Elevate the full thickness flap back to the SI joint. Carefully divide pelvic floor muscles off hemipelvis from ischium back to SI joint. Ligate sciatic nerve. Assistant holds the leg in abduction and flexion. Disarticulate SI joint. Close over drains. \*\*\* Can also do modified version where G Max left as part of flap. Osteotomize the ilium lateral to GMax origin \*\*\*

Question 44

Outline hip disarticulation

Answer 44

1. Apex of incision starts at 2cm medial to ASIS. Continue medially & distally through medial perineum and 2cm distal to ischial tuberosity, then 2cm distal to gluteal crease. Go posteriorly and laterally around leg then head back towards ASIS passing about 2cm anterior to GT. 2. Will have to ligate the saphenous vein, superficial epigastric and multiple external pudendal vessels. Expose the femoral triangle. Double ligate the femoral artery then vein. Traction then ligate the femoral nerve. 3. Release sartorius off ASIS then iliopsoas off LT. 4. Gracilis, adductors and pectineus released off of pelvis. Must ID and ligate obturator vessels and nerve bifurcating around adductor brevis. Release obturator externus from the femur (leave attached to pelvis!) 5. Hyperabduct the leg. Release hamstrings off the ischial tuberosity. Capsulotomy and cut the ligamentum teres. 6. Adduct the leg. Divide Gmax and TFL in line with skin incision. Release Gmax, abductors and short external rotators off femur. Dissect sciatic, traction and divide to allow it to retract into pelvis. 7. Sew gluteus medius and obturator externus over the acetabulum to reduce bony prominence. Approximate iliopsoas to quadratus femoris to reduce dead space. 8. Sew gluteal fascia to the inguinal ligament and the pubis. Interrupted skin closure with drain inserted deep to gluteal fascia. Compressive dressing for 3-5 days.

Question 45

Open approach to TFCC repair (type 1B)

Answer 45

Incision b/w 5th and 6th compartments L shaped DRUJ capsulotomy (protect dorsal radiocarpal ligament) Transverse ulnocarpal capsulotomy. Debride fovea Small K wire to make drill holes in dorsal ulnar neck exiting into fovea. 2-0 suture to repair TFCC to fovea, tie over ulnar neck. 6 weeks LAC then 2 more SAC. Recall classification: 1A central tear, 1B ulnar avulsion, 1C distal avulsion off carpus, 1D avulsion off radius

Question 46

Chronic DRUJ instability

Answer 46

Adams procedure ## Footnote Dorsal incision between 5/6. L shaped DRUJ capsulotomy. Volar-ulnar approach for retrieval. 3.5 mm drill hole in distal radius, 5mm from both lunate facet and sigmoid notch. 3.5mm drill hole in ulnar neck into fovea. Palmaris graft thru radius, into fovea, out the neck and around radial neck. Tie off and suture in reduced DRUJ position. Can add sigmoid notch osteoplasty PRN. Long arm immobilization for 6 weeks then short-arm for 2 more weeks.

Question 47

Considerations when choosing an ulnar shortening procedure

Answer 47

Goals: Neutral or -1mm ulnar variance _Wafer_ Maximum amount 4mm of shortening permitted. Avoids risk of nonunion. Must avoid damaging dorsal DRUJ ligaments and foveal TFCC attachment. Early ROM permitted. _Ulnar Shortening Osteotomy_ Preserves articular cartilage of ulnar head. No need to expose the DRUJ or ulnocarpal joint. Can generate joint mismatch/contact pressure at sigmoid notch. Must evaluate shape/inclination of DRUJ preoperatively. (Reverse oblique notch shape is risky for increasing contact pressure with ulnar shortening osteotomy).

Question 48

Ulnar shortening osteotomy

Answer 48

Subcutaneous ulnar approach, protect dorsal sensory branch of ulnar nerve. (Less plate irritation with dorsal placement.) Apply 7 hole small frag plate with distal end of plate 2cm from DRUJ. Insert distal 2 screws in neutral position. Loosen screws and swing plate over. Make oblique 45deg osteotomy. 2nd parallel cut (remember kerf of blade). Reduce proximal ulna, clamp under compression. Screw proximal screws under compression mode then insert a compression lag screw across osteotomy site. Closure. 2 weeks splinting then ROM. NWB until healed.

Question 49

Ulnar stabilization after Darrach

Answer 49

Breen-Jupiter technique ## Footnote Proximally based strip of ECU Distally based strip of FCU Thru drill holes/canal

Question 50

Degenerative DRUJ Considerations when selecting procedures.

Answer 50

_Hemiresection-interposition (Bower's)_ Relatively contraindicated in ulnar positive patients and patients with ulnar carpal drift. Beware using in younger patients as can result in radioulnar convergence and ulnar carpal drift. _Sauve-Kapandji_ Retains support for carpus. Potential for instability of stump, regeneration of resected 1cm segment of bone. Should interpose pronator quadratus and use strip of FCU for tenodesis. _Darrach_ Better for lower demand. Retains ulnar styloid and it's attachments. Should combine with ECU/FCU stabilization.

Question 51

Options for failed distal ulna resection

Answer 51

Can get radioulnar impingment or ulnar stump instability. ## Footnote _Options:_ Breen/Jupiter stabilization Ulnar head arthroplasty Interposition with pronator quadratus. Creation of one-bone forearm

Question 52

Scapholunate injury stages

Answer 52

_Stages_ 1. Partial tear (usually palmar and membranous part). Treat with physio or do scope and SL perc pinning. 2. Complete tear, repairable 3. Complete tear, irreparable, reduced (dynamic instability) 4. Complete tear, irreparable, subluxed but _reducible_ scaphoid (static instability) 5. Complete tear, irreparable, subluxed and irreducible scaphoid 6. Stage 5 with cartilage degeneration

Question 53

Describe the ligament preserving capsulotomy for dorsal wrist exposure

Answer 53

The incision starts at the tip of the radial styloid and progresses medially along the dorsal rim of the radius until approximately the center of the lunate fossa, where it takes a distal-oblique course following the fibers of the dorsal radial triquetrum ligament until its distal insertion onto the dorsal ridge of the triquetrum. Another incision is made at the level of the STT joint and progresses medially, splitting the fibers of the dorsal intercarpal ligament until its medial insertion onto the dorsum of the triquetrum

Question 54

Modified Brunelli (for stages 3 and 4) Must be irreparable and reducible

Answer 54

Dorsal approach. Fibre splitting capsulotomy. Check reducibility of SL articulation with traction or joystick pins. Dorsal transverse trough in lunate with burr or rongeur, suture anchor in trough. Drill hole thru long axis of scaphoid. Harvest 3-4mm wide distally base strip of FCR about 8cm long. Bring volar to dorsal thru the scaphoid. Bring tendon thru pulley of dorsal radio-triquetral ligament. Tension everything and insert SL and SC pins. Tie suture anchor in lunate, tie loop of tendon to itself.

Question 55

Therapy for osteoarticular TB

Answer 55

Isoniazid Rifampin Pyrazinamide Ethambutol

Question 56

Technique for midline lateral Lumbar discectomy (Paracentral disc)

Answer 56

1. Usual preop stuff, IV abx, xray to landmark, display preop xrays in the room. 2. Prone position Wilson frame, belly hanging free. 3. Midline incision 3-4cm. Incise midline fascia paramedian to the interspinous ligament. Subperiosteal dissection to expose posterior aspect of lamina and facet joint. Don't violate facet capsule. Need to see intralaminar space as well as half of cranial and caudal laminae. 4. \*\*\*Kocher on the SP and get another xray now\*\*\* 5. Use Kerrison to remove inferior edge of cranial laminae and strip the ligamentum flavum. 6. Identify thecal sac. Bipolar cautery for venous plexus. Identify exiting nerve root and dissect any adhesions. 7. Retract thecal sac/nerve root medially and remove disc fragment. May incise PLL to enter disc space and remove any loose fragments to prevent recurrence. May need to explore laterally in foramen or inferiorly in the root axilla. Add some topical steroid. Closure.

Question 57

Techinique for transmuscular far lateral discectomy

Answer 57

1. Preop IV abx, xray in the room, display preop films. 2. Prone position Wilson frame on Jackson table, belly hanging free to reduce venous congestion. 3. Check level with flat plate. 4. Incision 3-4 cm long, about 3-6cm from midline. 5. Incise fascia, bluntly separate multifidus and longissimus. Expose isthmus, TP above and below, facet joint. 6. Detach intertransverse ligament 7. Burr/kerrison to remove crescent of bone from superior isthmus and inferior aspect of cranial TP. Kerrison away the lateral ligamentum flavum. 8. Visualize and protect the nerve root and DRG. Resect disk fragments (usually medial and inferior to the nerve root). Can incise disk space to do limited discectomy. 9. Closure

Question 58

Technique for standard laminectomy (for central disc, or cauda equina syndrome)

Answer 58

Standard preop stuff, abx, have xray available, foley, display preop films, etc. Prone positioning in Wilson frame on jackson table. Position arms carefully prominences padded. 1. Landmark with xray. Midline incision. Cautery down to fascia. Open fascia just off midline on either side of SP. Subperiosteal dissection to expose dorsal side of lamina and facets. Avoid opening facet capsule if not doing a fusion. 2. CENTRAL DECOMPRESSION Leksell to partially remove half of cranial/caudal SPs and interspinous ligament. Use kerrison/burr to take down inferior half of the cranial lamina. Ligamentum attaching on undersurface. Kerrison to remove ligamentum flavum from cranial to caudal. Kerrison to remove superior half of caudal lamina. \*\*\*Make sure to achieve plane between LF and thecal sac before rongeuring the LF. This to avoid a dural tear\*\*\* 3. LATERAL DECOMPRESSION For safety, identify the pedicle. Use Kerrison to undercut the medial aspect of the facet. (no more than 50% of the facet to avoid destabilization). Don't violate the pars (to avoid destabilization). Examine exiting nerve root and may need to decompress the pedicle above or below. Examine for extruded disk.

Question 59

Gallie wiring technique

Answer 59

Skin incised from EOP to C45 level Careful subperiosteal dissection of C1 arch and C2 SP/lamina Decorticate under arch and above C2 SP/Lamina. Need to notch undersurface of C2 SP with burr. Wire looped anterior to C1 arch, loop brought inferior to the C2 SP. Tuck in the crest cortical graft. Free ends of wire crossed over graft and tied to secure.

Question 60

C1 C2 fixation pearls

Answer 60

_C1 lateral mass screw_ Start point at the lateral mass underneath where the arch meets the lateral mass. Protect C2 root. Aim slightly medial and superior (\<10degrees). Can check lateral fluoro to gauge the amount of sagittal angulation. Want UNIcortical purchase. Can use penfield 4 to palpate medially to ensure no breach. _C2 screws_ **Pars**: Inferior start point, midpoint of the C2/3 facet joint. 10-15degree medial angulation. Lateral fluoro to check sagittal angulation. Usually 12mm screw **Pedicle**: Superior start point (in line with top of C2 lamina). More lateral start than pars screw, aim about 20-25deg medial. Slight upward sagittal trajectory but not as much as a pars screw. Usually 20-24 mm screw. _Transarticular_ Inferior start in C2 but a bit more medial than pars screw. No med/lat angulation. Use lateral fluoro to gauge the sagittal angulation but aiming at the anterior tubercle of C1. Usually 40mm length. In picture, purple is transarticular, green is pedicle and blue is pars.

Question 61

Odontoid screw technique

Answer 61

Usually R side, transverse incision at C5 level. Dissect medial to SCM and the Carotid sheath, lateral to trachea and esophagus. Reach the prevertebral fascia at C5, dissect upwards. Identify C2-3 disc space on xray. May need partial discectomy midline to expose anteroinferior start point on C2. Drill K wire under biplanar fluoro into the fracture. Measure screw length and insert cannulated, partially threaded screw. Verify position on biplanar fluoro.

Question 62

Name of pins used in anterior C spine approach to provide distraction

Answer 62

Caspar pins Should plug these pins holes with bone wax afterwards.

Question 63

Unique preoperative considerations in spinal surgery

Answer 63

_Anterior C spine_ Carotid atherosclerotic workup _Thoracotomy_ Angio to identifiy Artery of Adamkiewicz

Question 64

Most common motor palsy after cervical spine surgery? How to prevent?

Answer 64

C5 palsy Do a concurrent C5 foraminotomy.

Question 65

Cervical laminectomy technique

Answer 65

Burr a longitudinal trough at the lamino-facet junction bilaterally. Burr down to the inner cortex. Use Kerrison to complete the trough. Grasp the cephalad and caudad SPs with kocher's to lift the en bloc laminae off. Carefully dissect the dura off first!

Question 66

Posterior cervical foraminotomy technique

Answer 66

3mm burr to decompress the lamina above and below the nerve root. Lateral extent is the medial 1/3 of the facet joint. Use kerrison to remove the ligamentum flavum medially. Picture shows decompressed nerve root

Question 67

Magerl technique for subaxial lateral mass screws

Answer 67

_Start point_ 1 mm medial to centre of LM 1-2 mm cephalad to centre of LM _Direction_ Aim 25 degrees laterally Aim 30 degrees superiorly (or parallel with superior articular facet on lateral xray)

Question 68

Pros and Cons of anterior vs posterior treatment after cervical dislocation

Answer 68

_Anterior approach_ Pro: Good fusion rate, can do direct neural decompression, maintains lordosis better, lower infection rate. Con: Approach related complications, fails in context of vertebral body fractures. _Posterior approach_ Pro: Rigid stable construct, familiar, can directly reduce dislocated posterior structures. Con: Prone position, higher rate of infection, risk of delayed kyphosis, higher postop pain.

Question 69

Prognosis for spinal cord injuries From Pahuta's notes

Answer 69

_Complete tetraplegia_ May recover 1 level. If 0/5 at 1 week, 50% chance of gaining 3/5 at 1yr. If 1 or 2/5 at 1 week, 100% chance of 3/5 at 1yr. If 0/5 at 1 month, 1% chance of 3/5 at 1 yr. If 1 or 2/5 at 1 month, 95% chance of 3/5 at 1yr. _Incomplete tetraplegia_ 50-75% chance of an ASIA C recovering to D or E 25% chance of ASIA B recovering to D or E _Complete Paraplegia_ T8 and above, expect no LE recovery T9-T11, 15% will gain 3/5 in L2 or L3 by 1 year T12 or below, 55% will regain LE function _Incomplete Paraplegia_ 80% will gain 3/5 in L2 or L3 by 1 year Most recovery in first 3 mos

Question 70

Technique for high grade spondylolisthesis List your indications for reduction of spondylolisthesis

Answer 70

_Indications_: Progressive high grade slip, high slip angle, bad sagittal balance _Posterior approach_ Instrumentation of L4, L5, S1 and Iliac screws. Laminectomy of L5, with decompression of L5 and S1 nerve roots L5-S1 disc removed; Sacral dome partially removed Fix rods distally, then proximally which reduces the spine by pulling L4 and L5 screws to the rod. Facilitate with extension moment of L4/5 screws and flexion moment at S1/Iliac screws. Must visualize the L5 and S1 nerve roots during/after reduction.

Question 71

Outline SLIC classification

Answer 71

_Morphology_ Compression 1 Burst 2 Distraction 3 Rotation/Translation 4 _Discoligamentous Complex_ Intact 0 Indeterminate 1 Disrupted 2 _Neurologic Injury_ Intact 0 Root 1 Complete 2 Incomplete 3 (+1 for continuous cord compression) 3 nonop 4 consider operative 5 operative

Question 72

Outline TLICS classification

Answer 72

_Morphology_ Compression 1 Burst 2 **Translation/Rotation 3** **Flexion/Distraction 4** _Posterior ligamentous complex_ Intact 0 Indeterminate **2** Disrupted **3** _Neurologic Injury_ Intact 0 Root 1 Complete 2 Incomplete 3 **Cauda Equina 3** 3 nonop 4 consider op 5 op Items in **bold** are where TLICS differs from SLIC

Question 73

Thoracic Pedicle screw landmarks for start Lumbar pedicle screw landmarks for start

Answer 73

Thoracic Midpoint of facet joint in line with superior edge of TP Lumbar Midpoint of facet joint in line with middle of TP

Question 74

Oral exam spiel for SCI

Answer 74

_Neurogenic Shock_: Pressors and maintenance fluids (after initial resusc) Consider swan ganz for CVP monitor Trendelenburg PRN _ICU_: Cardiopulmonary monitoring Maintain MAP over 85mmHg for 7 days MAP = (2\*Diastolic + Systolic)/3 _Other:_ DVT, Foley, Bowel protocol, GI ulcer prophylaxis, Skin checks/repositioning, nutrition NO steroids

Question 75

Outline treatment of congenital vertical talus

Answer 75

4-6 weeks of weekly serial casting in PF, inversion and forefoot adduction. OR: check meary's angle. If \<30 can do perc TN pinning, bury pin. If not, open medial approach to reduce joint. May require TN or medial subtalar capsulectomy to reduce. Pin TN joint. If open reduction required, transfer Tib Ant to dorsal talar neck with suture fixation as checkrein to loss of TN reduction Check PF. If \<25 lengthen EDC, TA and per brevis Perc achilles tenotomy AFTER TN joint pinned