exam 1

medial condyle

• larger

• projects more distally

screw home mechanism

medial condyle is longer and forces tibia to rotate outward as leg moves into full extension

lateral condyle

• smaller

• projects more anteriorly

which condyle serves as the main contact surface to stabilize patella

lateral

which ligmanents are extrasynovial

cruciates

which way does the patella naturally want to move

laterally

at the proximal tibfib joint, what is convex and what is concave

• fibular head: concave

• tibia: convex?

ACL

• guides normal motion

• restrains anterior translation of tibia

• restrains IR/ER of tibia

PCL

• guides normal motion

• restrains posterior translation of tibia

• restrains valgus stress

what positions make the antereomedial and posterolateral fiber bundles of ACL most taut

anteromedial: flexion, valgus, IR

posterolateral: full extension/valgus

what positions make the antereolateral and postermedial fiber bundles of PCL most taut

• anterolateral: flexion

• posteromedial: extension

what factors contribute to noncontact ACL injury

• strong activation of quads over moderately flexed or nearly extended knee

• valgus collapse

• excessive ER

MCL

• restrict valgus

  • superficial: small degrees of flexion

  • deep fibers: full extension

• restricts anterior translation of tibia

LCL

restricts varus, tibial ER, and extension

which is more mobile

LCL

what makes up the arcuate ligamentous complex

• LCL

• biceps fem

• ITB

• popliteus tendon

what position is MCL most likely to be injured in

• extension

• valgus load and planted foot exacerbates injury even more

anterolateral ligmanet (ALL)

resists anterior tibial translation and IR

what ligaments help support the posterior joint capsule

• posterior oblique

• oblique popliteal

arcuate popliteal ligament

stabilizes against hyperextension and excessive ER

medial patellofemoral ligament (MPFL)

restrains lateral subluxation as knee approaches extension

medial meniscus

• semi-lunar or c-shaped

• thicker and larger

• less mobile

lateral meniscus

• circular or o-shaped

• smaller, thinner

• MORE MOBILE

what ligament improves lateral meniscus mobility

ligament of humphry and wrisberg

lateral retinaculum

• deep to ITB

• blends with LCL to form conjoint tendon on head of fibula

• STRONGER AND THICKER

medial retinaculum

blends with MPFL

what happens when you lock the knee

• OKC: ER of tibia

• CKC: IR of femur

what happens when you unlock the knee

• OKC: IR of tibia

• CKC: ER of femur

what is the closed packed positions

full knee extension

which movement does the capsular pattern favor

flexion

patella alta

• patella high in groove

• can lead to instability

patella baja

patella sits low in groove

what q angle is abnormal and what does it lead to

• > or equal to 20

• increases lateral patellar forces

superior forces of PFJ

quads via quad tendon

lateral forces of PFJ

• lateral retinaculum

• VL

• ITB

• stronger compared to medial forces

medial forces of PFJ

• medial retinaculum

• VM

inferior forces of PFJ

patellar tendon

what is the #1 cause of PFJ dysfunction

• maltracking

• train and track analogy

ottawa knee rule

• criteria to determine who gets x ray

• age > 55

• isolated patellar tenderness

• tenderness to fibular head

• inability to flex to 90°

• instability to WB immediately after injury and in ER

symptoms of ACL tears

• femoral IR, knee ER, w or w/o valgus force/hyperextension

• audible pop → knee “giving away”

• hemarthrosis + swelling

• WB instability

• can’t continue participation

segond fx

small avulsion fx of lateral tibia condyle just below joint line

what tests to use for ACL tears

• lachman (gold standard)

• anterior drawer

• pivot shift

coper

asymptomatically resume all pre-injury activities for at least 1 yr w/o surgery

potential coper

• identified via screening

• good potential to cope non-operatively

non-coper

can’t return to high-level athletics due to continued giving away episodes

adapter

chooses to reduce activity levels to avoid instability

classification criteria of copers

• Knee Outcome Survey ADL Scale: ≥80% 

• Global rating of knee function: ≥60% 

• Episodes of "giving way": ≤1 

• Timed 6-meter hop: ≥80% (compared to uninvolved side)

• MUST MEET ALL CRITERIA

classification criteria of noncopers

• Competitive athletes seeking the "best possible knee." 

• Associated meniscus or collateral ligament injuries.

• Large amount of anterior translation during laxity testing.

• Failed conservative rehabilitation (frequent giving way).

coper clinical presentations

• Confirmed ACL insufficiency via MRI or KT 2000

• No/mild knee effusion

• Full active knee ROM w/o pain

• Quad strength ≥70%

• No knee pain

• Ability to hop on one knee

noncoper presetations

• Repairable meniscus tear with ACL insufficiency 

• Full thickness chondral defect

• Concomitant ligament laxity, LE & back injuries

• Unable to hop

• Bilateral knee involvement 

phase 1 goals for post op & non op rehab

• REGAIN FULL EXTENSION!!!!

• reduce swelling and inflammation

phase 2 goals for non op rehab

dynamic stabilization

phase 3 goals for non op rehab

neuromuscular activity

phase 4 for post op & non op rehab

make it harder

post op week 1 knee flex target

90

post op week 2 knee flex target

105-115

post op week 3 knee flex target

115-125

post op week 4 knee flex target

> 125

what range can you move for active knee extension during weeks 2-3 (OKC)

40-90°

what range can you moe for active knee flexion during weeks 2-3

40-100°

which graft has a higher chance of ailing

allografts

ppl who get surgery are more or less likely to receive follow up surgeries

less

PCL is more likely to be injured due to

hyperflexion

special tests for PCL

• posterior sag sign

• posterior drawer

• godfreys

• reverse lachmans

grade i PCL

• 0-5 mm posterior translation 

• Medial tibial plateau remains anterior to medial femoral condyle

grade ii PCL

• 5-10 mm posterior translation 

• Medial tibial plateau rests flush w/ medial femoral condyle

grade iii PCL

• > 10 mm posterior translation 

• Tibial plateau posterior to condyle

PLC injury presentation

• non-contact hyperextension & ER twist

• patellofemoral directed blow to anteromedial proximal tibia

• high-energy blow to flexed thigh

PLC special tests

• varus testing at 0 and 30°

• dial rotation test

• hughston’s

• reverse pivot shift

PFPS presentation

• behind or around patella

• anterior knee pain (often bilat)

• increased pain w/ stair climbing and squats (deep flexion)

jumper’s knee presentation

• patella tendon pain

• hx of repetitive overuse of jumping and/or running

SLJ syndrome presentation

skeletally immature pt

osgood-schlatter presentation

• active, skeletally immature pt

• hx of squatting, jumping sports

• TRACTION INJURY!!!!

DJD/OA presentation

• insidious, gradualy onset

• stiffness in AM with prolonged static positions

OCD presentation

• vague insidious onset

• clicking, popping, or locking

MCL tear presentation

• forced valgus injury

• medial knee pain

• pain with sleeping on side

meniscus tear presentation

• pain with twisting, deep knee flexion

• knee locking

acute patellar dislocation/subluxation presentation

knee felt like it shifted

acute patellar dislocation/subluxation symptoms/findings

• TTP at medial retinaculum/MPFL

• + apprehension test

• x ray shows patella subluxated or osteochondral fx

PFPS clinical findings

• TTP at patellar facets

• crepitus and pain

jumper’s knee symptoms/findings

TTP to patella tendon

SLJ syndrome symptoms/findings

• TTP to patellar inferior pole

• x ray shows changes at inferior pole

• palpable bump at inferior pole

osgood-schaltter symptoms/findings

TTP to a prominent tibial tubercle

DJD/OA symptoms/findings

• TTP at joint line

• x ray shows joint line narrowing

• osteophytes

• deformity (advanced)

• effusion (variable)

OCD symptoms/findings

• mild effusion

• x ray shows fibrillations and lesions

• MRI may show vascular changes

MCL tear symptoms/findings

• TTP at MCL

• increased genu valgum

• local effusion

• + valgus stress test

meniscus tear symptoms/findings

• TEAM J

• lack of knee ext with larger tears

patella arthrokinematics during flex and ext

• flexion: glides inferior

• extension: glides superior

OKC knee ext arthrokinematics

anterior glide of tibia on femur

OKC knee flex arthrokinematics

posterior glide of tibia on femur

CKC knee ext arthrokinematics

femur glides posterior on tibia

CKC knee flex arthrokinematics

femur glides anterior on tibia

which pole of the patella is the only one to articulates with femur

inferior

what makes up the unhappy triad

• ACL

• MCL

• MM

MCL grade i injury

• + palpatory tenderness

• normal valgus laxity

MCL grade ii injury

• increased valgus laxity @ 20-20°

• soft end feel

MCL grade iii injury

• greatest valgus laxity @ 0 and 20-30°

• soft end feel

LCL injury signs and symptoms

• knee swelling

• stiffness of knee joint that causes locking of the knee

• pain/soreness on outside of knee

• instability of knee joint

what creates a higher risk of menisci degeneration

stair climbing

what position increases the risk for knee OA

kneeling