Claw vs hammer vs mallet
Claw: MTP extension
Hammer: PIP flexion
Mallet: DIP flexion
Important HX questions for knee injuries?
Onset of pain
Location of pain
Injury-associated events (catching/locking, pop etc)
What are the degrees of immediate dysfunction
Unable to ambulate
Antalgic gait
Continued to participate (sports)
Knee anterior structures
Tibial tubercle Infrapatellar tendon Quad insertion Patellar facets Crepitus
Posterior knee structures
Meniscus
Popliteal fossa
Hamstring tendons
Medial knee structures?
MCL Meniscus Pes anserine Tibial plateau Femoral condyle
Lateral knee structures?
LCL Meniscus Gerdy’s tubercle Tibia plateau Femoral condyle
posterior lateral corner of knee injury involves what structures?
Lateral collateral ligament
Popliteus tendon
Popliteofibular ligament
Lateral gastrocnemius
Theatre sign?
Prolonged sitting causes patella pain.
Knee is in relaxed flexed position, the patella will ride on one side of the knee and it will cause pain.
Noncontact injury with “pop” is probably?
ACL tear
Contact injury with “pop” is probably?
MCL, LCL tear
Meniscus tear
Fracture
Acute effusion (<12hrs) is probably?
ACL tear PCL tear Fracture Knee dislocation Patellar dislocation
Lateral blow to the knee is probably?
MCL tear
Medial blow to the knee is probably?
LCL tear
Knee “gave out” or “buckled” is probably?
ACL tear
Patellar dislocation
Fall onto flexed knee is probably?
PCL tear
Joint injuries and their likelihood of hemarthrosis?
ACL: 65-70% Meniscus: 12.5-50% Fracture: 1-20% Patellar dislocation: 11-20% W/ osteochondral lesion: 5% PCL: 1-5%
Genu varum vs genu valgum?
Varum: knees out
Valgum: knees in (gum)
Diagnostic studies you should get on pts with genu varum and ganu valgum?
Leg length radiographs and hip radiographs
The deformity may be in the hip or legs not the knee
Q angle?
ASIS-patella and the plane of the tibial tuberosity (hip form affects the femoral to tibial angle)
What is normal Q angle?
Male: 15%
Female: 20%
Special tests for knee?
Lachman test Apley compression test Anterior drawer test Lateral pivot shift test McMurray test
Slide 19 has pics
Patellofemoral stability test?
Slide patella back and forth
Normal
- patellar slide: 25-50%
- patellar tilt: 15*
Just compare the knees to look for difference
Slide 20
What MOI causes patellar dislocation?
Direct trauma
Rotation over planted foot (softball swing)
Sudden cutting movement
Prior injury
What radiography should be ordered for knees, why?
x ray: because its everything
MRI: r/o associated injuries
Valgus stress test?
MCL
Pull ankle laterally and push knee medically, look for laxity in MCL
at 0* no laxity
At 30* some laxity
Slide 24
MCL tears and rupture prognosis?
Proximal ruptures: heal quickly but are stiff
Complete ruptures: can displace joint
Entire ligament: persistent laxity after non-operative tx
Varus stress test?
LCL
Pulling ankle medial and pushing knee lateral
Slide 26
Lachman test?
ACL
Stablize thigh and pull leg toward you (w 30* flexion) and laxity = badness
Slide 27
Pivot shift test?
ACL
Push knee up and medial looking for laxity
Slide 28
“A lachman is as good as?”
“An MRI”
Anterior drawer test?
ACL
“These suck”
Lachman test sensitive and specificity? (ACL)
Sensitivity: 87%
Specific: 93%
Anterior drawer test sensitive and specificity? (ACL)
Sensitive: 48%
Specific: 93%
Pivot shift test sensitive and specificity? (ACL)
Sensitive: 61%
Specific: 97%
Joint line tenderness sensitive and specific? (Meniscus)
Sensitive: 76%
Specific: 95%
Thessaly test sensitive and specific? (Meniscus)
Sensitivity: 90ish
Specific: 95%
McMurray test sensitive and specific? (Meniscus)
Sensitivity: 52%
Specific 97%
Positive McMurrays test?
Pain or pop
Slide 33
Thessaly test
Pt stands in one foot while holding you for balance. They rotate internal and external.
Positive test will get popping and clicking
Conducted with foot at 5* them 20* flexion with the foot flat
Slide 32
Posterior sag test?f
PCL
Knee at 90* and the tibia is not a straight line
Slide 35/36
Dial test?
PCL
Symmetric: normal
Asymmetric: abnormal
Pt lying prone and feet should mirror each other when knee is flexed at 30*
Slide 37
What is noble’s test?
(ITB)
Palpate lateral femoral condyle
Flex and extend knee
Pos: pain at site of palpation
Ottawa knee rules?
When to order an x ray
Age >55 or <18 Unable to walk TTP on patella TTP on fibular head Unable to flex 90*
How accurate is the ottawa knee criteria?
100% sensitive
Reduced radiographs by 49%
What to look for on lateral images of knee?
Patella alta/baja
Patellar poles
Fat pads/bursa
Evaluate avulsion fx
What is patella alta/baja?
Patella Alta: high riding patella
Patella baja: low riding patella
Not affect knee mobility
What is Sunrise imaging?
Patella rising over knee like the sun over the mountains
Sunrise imaging assesses?
patellofemoral joint
Patellar tilt
Lateralization
Depth of trochlear groove
What is a pellegrini stiega?
Avulsion fx of MCL on femur
What should you look for in the joint space between femur and tibial heads?
Discoid meniscus:
- Squaring
- Widening
- Cupping
How common are ACL ruptures?
200,000 ACL rupture per yr in the US
1 in 3500 people
Should i fix acl ruptures?
Yes:
Reconstruction is demonstrated to reduce sequelae of chordal and meniscal injury.
Who is more likely to get ACL rupture? Why?
Females > males Wider pelvis (wide Q) Greater flexibility Less muscle development Hypoplastic vastus medialis oblique Narrow femoral notch Genu valgum External tibial torsion
ACL bundles?
2 of them
AM: tight in flexion
PL: tight in extension
What is the primary stabilizer of the knee against anterior translation?
The ACL
What tends to cause acl rupture?
Rotational (twisting)
Hyperextension force
Usually noncontact injuries
What is the knee terrible traid?
Concomitant injuries:
- Meniscal tear
- Medial collateral ligament
- ACL rupture
Why is blood in the joint bad?
Blood is an irritant
What is a risk (uncommon) with disruption of multiple ligaments of the knee?
Popliteal artery
It is a limb threatening emergency
Clinical presentation for ACL rupture?
Instability immediately
1/3 hear a pop
Unable to continue training
Immediate effusion
What causes joint effusion with acl rupture?
Edges of the torn ligament bleeds into the joint (hemarthrois)
ACL rupture PE?
Decreased ROM
Effusion-hemarthrosis (immediate)
Instability tests
+/- MCL and meniscus test
What instability tests are positive with ACL rupture?
Lachman (most accurate)
Pivot shift
Anterior drawer
Do they need an MRI? (ACL)
No
Clinical exam is as good as MRI
What is good about and MRI? (ACL)
It is sensitive and specific
Shows concomitant injuries
What are kissing lesions?
ACL tear MRI finding:
-Anterior lat femoral condyle
- Posterior lat tibial plateau
Touch on MRI
Initial tx for ACL rupture?
RICE
Early ROM and PT
ROM brace is used
What is the key for ACL rupture management?
Early ROM exercises
Full ext/flexion as soon as swelling permits
What will surgery not fix for ACL ruptures?
The risk of OA
CI for surgical repair of ACL rupture?
Age >40 Stiffness Response to non-operative therapy Advanced arthritis Compliance issues
What can you hope for with ACL nonoperative tx?
ROM of at least 0-120
Strength: quadriceps and hamstring w/in 90%
Surgical options for ACL rupture?
Patella tendon autograft
Hamstring autograft
Allograft
Patella tendon autograft info?
Most popular (NLF uses it)
Stable: late rupture is rare
Anterior knee pain is common
Hamstring autograft info?
MC in low intensity athletes
No anterior knee pain
Strength/stiffness is based on fixation method
Allograft information?
50% strength of autograft
Used to augment or when donor tissue sucks
Expensive
What is the risk of nonsurgical tx for ACL rupture?
Recurrent instability
Meniscal tears
Degnerative joint disease
ACL surgery adverse outcomes?
Arthrofibrosis (scarring)
Numbness lateral to incision
Why do pts get numbness following ACL repair?
Infrapatellar branch of saphenous nerve is compressed
Often spontaneously resolves
What is the PCL?
Posterior cruciate ligament
Critical ligament in the knee and serves as the primary restraint to posterior translation of the tibia relative to the femur
Anatomically where is the PCL found?
Originates on the medial intercondylar wall of the femur, runs obliquely behind the anterior cruciate ligament and inserts on the posterior aspect of the tibia below the joint line
What is the MC cause of PCL injury?
Direct blow to the tibia such as dashboard injury in MVA
Why are PCL injuries often missed?
If you have an isolated PCL injury you can usually function at a near-normal level
Injury patterns that suggest PCL rupture?
Dashboard inj
Fall onto flexed knee w foot in plantar flexion
Hyperextension of knee
Hyperextension strong enough to rupture ACL and PCL
PE for PCL rupture?
Effusion Posterior drawer test Posterior sag sinn False positive lachman test ACL and PCL injury
Radiographic studies for PCL?
MRI = useful for PCL and concomitant injuries to surrounding tissue
Adverse outcomes of PCL rupture?
Limb threatening vascular injury (dislocated knee)
Permanent perineal or tibial injury and sever knee instability can occur
Recurrent instability, subsequent tears and OA
What is the basis of PCL injury tx?
Initial: resolve swelling and restore ROM
After: strengthening exercises
Braces: for contact sports after return to sports
What is the purpose of the medial and lateral collateral ligaments?
They are outside the joint and stabilize the knee against valgus and vargus stress
What is the MOI for collateral ligament injury?
MC: Valgus force w/out rotation
“Clipping” injury
Less Common: pure vargus force to the knee
What other things are commonly injured with collateral ligament injuries?
Popliteus tendon Popliteofibular ligament Peroneal nerve (extreme case) Biceps femoris tendon (extreme case)
Can pts usually walk with collateral ligament injury?
Usually can ambulate and sometimes even return to play
Swelling for collateral ligaments?
Sometimes localized ecchymosis after 24-48hrs
PE findings with collateral ligaments?
TTP along joint line
Pain +/- instability with valgus (MCL) or varus (LCL) stress
Compare the sides
Swelling is often associated w collateral ligament injuries but what if its large effusion?
Often indicates associated intra-articular injury
tenderness in MCL injury?
Tender along entire course from:
Medial femoral condyle to broad tibial insertion
Just distal to the pes anserinus
Tenderness with LCL?
Tender anywhere along the course from lateral femoral epicondyle to its insertion on fibular head
Best position to palpate MCL?
Slight flexion
Best position to palpate LCL?
Figure 4 position
Laxity in full extension for collateral ligaments indicates?
More extensive injury to the anterior and posterior crucial ligaments plus posterior capsule rather than to just the MCL or LCL
Collateral ligament grades?
Measure of joint space opening:
Grade I: <5mm: interstitial tear
Grade II: 6-9mm: partial tear
Grade III: >10: complete tear
Are x rays good for collateral ligaments?
Ap and lat are usually negative however:
May reveal an avulsion fx
When should you order an MRI?
When multilligament injury is suspected with gross laxity stress at 0 degrees
Why are collateral ligament injuries usually treated nonsurgically?
They are extra-articular and have good blood supply so they can heal on their own
Tx for isolated grade I and II collateral ligament injury?
Supportive:
- RICE
- Crutches
- NSAIDS
ROM exercises early
Hinged brace
Grade III MCL injury tx?
Proximal and w/in midsubstance can be treated nonsurgically w hinged brace
Why should long term immobilization be avoided with collateral ligaments (or anything really)?
Stiffness tends to develop
How long will collateral ligament injuries be in a brace?
3-4 months
Who gets surgery (collateral ligament)?
Isolated grade III LCL injury usually involving posterolateral capsular complex and popliteus tendon
How are avulsions usually treated?
Usually repaired and need to be done w/in 7 days of injury
What is the big concern with collateral ligaments post healing?
Recurrence of injury is common especially for first 6 months
What collateral ligaments get to go to ortho?
Hemarthrosis
Significant effusion
Instability
Grade III
What needs to be done with posterior lateral corner injuries?
Consult w/in 72hrs
Give 100%
110% is impossible, only idiots recommend that
- ron swanson