Dx and Tx of Common Knee Injuries

What is patellar tendinopathy? Common sports?

AKA Jumper's knee. Pain, dysfunctiom, cellular change of patellar tendon. Common in basketball, volleyball, high jumping

3 stages of continuum of tendon pathology

1) Reactive tendinopathy

2) Tendon dysrepair

3) Degenerative tendinopathy

T or F, Patellar tendinopathy can purely be diagnosed via imaging

False, you can have a good tendon on imaging but still have signs and sx

Patellar tendinopathy diagnosis

Pain at inferior pole patella oR mid substance of patellar tendon

Pain with knee extensor load

MRI or ultrasound indicating degeneration

Tx for patellar tendinopathy

Temporarily reduce load, use heavy strength training to load tendon, gradually reintegrate sports activity

What does tendon loading accomplish?

- Decrease pain

- Increase strength

- Increase load tolerance/endurance

Patellar tendon loading should be initiated with....Give an example

isometrics (EX: Heavy knee extension hold, 4 sets 30-45 sec)

T or F, if a patient feels mild to moderate pain or discomfort during isotonic loading, we should cease exercise

False, slight discomfort is ok

ACL Primary and secondary restraint

P: Ant. translation of tibia on femur

S: IR of tibia on femur

S: Varus/valgus

Why is the anterior drawer less sensitive for acl tear Dx?

Due to guarding of hamstrings

_______ are at higher risk for ACL injury than males. List some reasons why...

females due to...

- Wider hips/Q angle

- Decreased muscular strength

- Increase quad dominance

- Increased laxity

- Decreased trunk/hip/knee flexion angles during sports

Associated injuries with ACL tear

Bone bruising of lateral joint surfaces

Meniscal tears

Additional ligaments

Unhappy triad knee

ACL, MCL, medial meniscus

T or F, research says combined injuries to ACL, MCL and LAT meniscus are more common

true

Instability vs laxity

Instability is a subjective complaint whereas laxity is a measurable objective finding

Graft choices for ACL reconstruction

Autograft: Bone-tendon-bone patellar tendon

Hamstring graft (semiten, gracilis)

Allograft (cadaver) (Good for older or less active pts)

A patient comes in after ACL reconstruction and the surgeon used a bone-tendon-bone patellar tendon graft. He is complaining of pain and discomfort at his anterior knee during exercise. What should we do?

If its not an intolerable pain, we continue with rehab. It is common to have anterior knee pain with BTB graft

What is graft ligamentization?

Process by which tendon graft changes to resemble ligament. Involves...

Change in vascularization

Cell change in orientation

Change in collagen alignment from irregular to parallel fibers

What is arthrogenic muscle inhibition?

Ongoing inhibition of musculature surrounding an injured joint

True or false, ACL is a proprioceptive organ

true, it has mechanoreceptors

Muscles weakened after ACL reconstruction

quads

Main goal of early phase ACL rehab (0-6 weeks)

Manage pain/swelling

Regain full ext

Quads re-ed

T or F, we should be cranking the knee into flexion to gain flexion ROM after ACL reconstruction

false, flexion normally gained naturally.

T or F, ACL reconstruction has WB restriction

false

Why is there restriction in knee flexion after ACL reconstruction?

Not muscular, due to neurological tone

Components of ACL rehab middle phase (around 6.5 weeks)

Should be reaching full ROM, progress to heavier strength training, key is to achieve heavy load without provoking inflammatory response

*QUAD STRENGTH IS MAIN PRIORITY**

Why is Quad strength important after ACL reconstruction?

Correlate to self reported function, decrease reinjury rate, decrease risk of post traumatic OA

T or F, research states that OKC exercise such as loaded knee extension is ok for ACL rehab

true

ACL Rehab late phase components

aggressive strengthening and NM control training. Reintegration of dynamic activity such as reactive agility or cutting

When does jogging usually start after acl rehab? What about if there was a meniscus injury with it?

3.5 months, add one month if there was a concurrent mensicus repair

Quad strength to run...

1.7x BW, and >75% Contralat limb

Timeline for acl return to sport

9-12 months

Function requirements post acl reconstruction for return to sport

Full ROM, no pain/effusion

Quad strength 90% of non-op side, hop test 90% compared to non op side, no apprehension with specific mvmnt

returning to sport prior to 9 months was associated with a ____ fold increased rate of second ACL injury

7

______ meniscus resists anterior translation while the _______ meniscus resists rotation

medial resist ant. translation

lat. resist rotation

Describe the zones of the menisci

Outer zone: Red zone, good healing potential

Inner zone: white zone, poor healing potential

Middle zone: Pink zone, semi vascular, some healing potential

Meniscus injury diagnosis tests and and sign

thessaly, mcmurray, hyperflexion + rotation test

Joint line tenderness

Meniscal Composite Score

Need 3 or more to call it a meniscus injury

1) Pain w max flexion

2) Pain w/ forced hyperext

3) Joint line tender

4) Pain or audible click in McMurray

5) History of catch or lock

Indication for surgical repair vs menisectomy

Surg repair: Young, tear in location with good healing potential, acute vs degen.

Menisectomy: Tear in area with poor healing, true mechanical lock

ROM restrictions for meniscus repair

ROM restriction for 4-6 weeks

0-90 degree flexion

Locked in extension brace while WB

Return to sport 4-6 months

T or F. Meniscectomies have heavy precautions with slow return to sport

false, minimal precaution, quicker return to sport

Important strengthening principles after meniscus injury post op rehab

Quads, glute/hip, NM control

MCL primary and secondary restraint

P: Valgus stress

P: ER of tibia

S: Ant. translation

What type of treatment is standard care for isolated MCL injury?

non-op

PCL primary and secondary restraint

P: Post. translation of tibia on femur

P: Hyperext

S: ER of tibia

S: Varus and valgus force

3 tests for PCL

Post. drawer, Post. sag sign, Active quad drawer test

Consequences of PCL insufficiency

Pain, instability with activity, PF Sx

PCL insufficiency has a high likelihood of developing...

medial compartment DJD

PCL Tx crucial components

Quad strength

Avoid deep squat or deep knee flexion with strengthening

Avoid early OKC due to shearing

LCL primary and secondary restraint

P: Varus stress

P: IR of tibia

S: Ant. translation of tibia on femur

Is LCL tear usually a contact or non-contact injury?

Contact

LCL injury treatment components

Early protection, avoid early varus stress, strengthen quads, glutes, core

Structures implicated in posterolateral corner

LCL

Popliteus

Popliteofibular lig

Arcuate lig

Fabellofib lig

Lateral joint capsule

Bicep femoris, IT band, lateral head gastroc

MOI for posterolateral corner injury

Hyperext + Varus

Posterolateral directed force on flexed knee

Extreme tibial ER

Dial test positive at 30 vs 90

30: Post. Lat corner

90: Post. Lat. corner and PCL

Posterolateral corner has a ____ week window to perform surgery before outcomes decline. What nerve can be harmed?

2 week window, it is an emergency, needs rapid dx and tx. Peroneal nerve (common fib)