Knee Injuries

uniplanar

instability in one cardinal plane

occur to only one structure

rotational injuries

abnormal tibial rotation

named based on direction of Sx of tibia on femur

multiple structures are injured

feeling of “giving way”

MCL layers

deep: attaches to medial meniscus

superficial: attaches 7-10 cm below joint line

MCL in motion

extension: both layers tight

midrange: anterior fibers tight

full flexion: posterior fibers tight

MCL

protect against valgus force

limits ER of tibia

anterior translation of femur

MCL sprain

MOI: valgus force, foot planted increased severity, 25 ext increased severity

S/S: pain, swelling/discoloration, limping

special test: ant/post drawer, McMurray’s

treatment: RICE, compression foot to thigh

LCL

O: lateral femoral condyle

I: proximal fibular head

function: restrains varus, resisits IR and ER tibia on femur

LCL sprain

MOI: blow to medial knee

Special test: varus, valgus, ant/post drawer, lachman’s

Tx: start like MCL

ACL Sprain

MOI: anterior translation of tibia on femur, posterior translation of femur on tibia, hyperextension of knee, rotational force

risk factors: poor muscular strength, poor coordination, shoe and/or surface, biomechanics (pes cavus, anterverted hips), joint laxity, limb alignment (q angle, genu recurvatum), narrow intercondylar notch, smaller ACL

presentation: sidelying clutching flexed knee, non weight bearing, extreme pain

on field knee eval

limited time

be confident

calm patient

assess pulses, boney involvement, ligamentous integrity, ability to bear weight

special tests: femoral and pedal pulses, MFT, lachman’s and anterior drawer, posterior drawer

ACL post acute presentation

general effusion

feels like a bone filled with jelly (ballotable test)

distal quad definition swallowed by effusion

pay attention to suprapatellar region

complain of tightness, giving way

ACL and PCL injury management

RICE

Stim for pain control

knee immobilizer and compressionette

crutches

refer

ACL grading system

partial thickness tear OR

mid-substance tear (anteromedial bundle)

complete tear

partially torn ACL

biomechanically dysfunctional

prone to additional injury/increasing laxity of uninjured fibers

unstable knee

early onset degenerative arthritis

ACL Pre-hab

full ROM

strengthen quads, hams, calf

prepare pt: explain importance of rehab, explain surgical procedure

surgery graft options

1. middle 1/3 patellar tendon graft (bony blocks allow for interface screw placement into tibial femoral tunnel

2. semitendinosus graft

3. allograft

initial ACL rehab

start 1 day post op

RICE for pain

Quad sets (muscle re-education)

straight leg raises

ankle pumps

heel slides

patellar mobilization

wound care

PCL injury

less common in sports

MOI: posterior translation of tibia on femur, car accident, falling on flexed knee, hyperextension

posterior dynamic stabilizers: popliteus, soleus, hamstrings, arcuate ligament

Special Test: posterior sag, posterior drawer, godfrey 90/90, quad active contraction

PCL treatment

based on:

uniplanar vs rotary injury

functional ability

point in the season

will be braced

PCL rehab

manage acute

strengthen hams, gastroc, quads

limit unnecessary pounding or cutting (water therapy, or elliptical)

long term: mechanical changes in function and structure of ACL, meniscal involvement

degenerative changes

rotary instabilities

biplanar rotation of tibia off the femur

posterolateral is the most common

AMRI

MOI: excessive valgus force , force at posterolateral corner

damaged structures: ACL, MCL, medial meniscus, posterior oblique lig.

special tests: anterior drawer, solcum

ALRI

MOI: excessive varus force, force at posteromedial corner

damaged structures: ACL, LCL, posterior lateral capsule, arcuate ligament complex, IT band

special tests: anterior drawer, solcum, pivot shift

PMRI

MOI: excessive varus force, force at posteromedial corner

damaged structures: PCL, MCL posterior oblique ligament, perhaps posteromedial capsule

special tests: posterior drawer, hughston

PLRI

MOI: excessive varus force, force at anteromedial corner (often seen with knee dislocations)

damaged structures: ACL, PCL, LCL, arcuate ligament complex

special tests: posterior drawer, hughston, external recurvatum test

posterior oblique ligament

commonly damaged in AMRI and RMRI

arcuate ligament complex and posterolateral compartment

commonly injured in ALRI and PLRI

1. arcuate lig.

2. lateral head of gastroc

3. popliteus

4. popliteofibular lig.

5. LCL

6. IT band and biceps femoris

role of meniscus

limited blood supply

cushion btw tibia and femur

protect articular cartilage

deepen the bowl btw tibia and femur

feedback for joint position

medial meniscal tear

bucket handle tear :mechanical extension block “giving way”

large flap tear: results in clicking/popping

radial (longitudinal) tear: often seen in vascular zone, less likely to require surgery

lateral meniscal injury

often seen with chronic overuse

not as much concern about chondral changes

osteochondral dissecans

long term, chronic changes to articular surface

• side of defect

• depth of defect (used to grade severity of damage)

can result in floating bodies

• pain with AROM

• can be removed with surgery

• “joint mice”

OCD grading

1. generalized soreness

2. articular cartilage softens

3. affected area starts to collapse

4. affected area starts to flake off underlying bone

5. loose body forms

OCD treatment

conservative: rehab, remove from aggravating activities

invasive: salvage articular cartilage, drill holes in fibrous tissue, affix with screws, rest/rehab

plica

synovial remnant from fetal stage

most commonly seen at medial infrapatellar region

wide band of fibers with no real purpose

thick, feels like cords under the skin

medial patellar plica

originate at medial joint wall superior to patella

pass distally near femoral condyle

insert close to prepatellar fat pad

Osgood Schlatter’s disease

common in adolescent males

rapid growth spurt

apophysis fracture secondary to rapid bone growth

excessive bone growth at tibial tuberosity

S/S: pain after activity, pain after bumping knee

Tx: Ice, NSAIDs, quad stretching, surgery to shave off tibial tuberosity

larsen johannson disease

seen at 10-15 yrs old

occurs at inferior proximal pole of patella at insertion of patellar tendon

MOI and treatment the same as osgood schlatter

tibial periostitis

inflammation of middle two thirds of tibia

linked to muscle/tendon/periosteal irritation

MOI: overexercising, poor shoe choice, often confused as shin splints

treatment: RICE, NSAIDs

IT band friction syndrome

chronic use

friction btw IT band and lateral femoral condyle

secondary to bursitis