Knee PROM, MMTs, Special Tests and Differential Dx

knee PROM flexion normal range

0-150°

knee flexion end-feel

soft due to muscle bulk OR firm due to tightness/capsular tension

knee extension end-feel

firm due to muscle tension, posterior joint capsule, or ligaments

knee ext/flex PROM axis

lateral epicondyle

knee ext/flex PROM stable arm

midline femur (greater trochanter)

knee ext/flex PROM moveable arm

midline fibula (lateral malleolus)

valgus stress test

tests for integrity of MCL

valgus stress test positive sign

empty end-feel; increased joint glide relative to opposite side; sx reproduction; abnormal 6-10mm, severely abnormal >10mm

valgus stress anatomical rationale

test places a stretch on MCL, which would reproduce sx (pain and/or instability) in the presence of a sprain

varus stress test

tests integrity of LCL

varus stress test positive sign

excessive varus movement, pain; abnormal 6-10mm, severely abnormal >10mm

varus stress anatomical rationale

test places a stretch on LCL, which would reproduce sx (pain and/or instability) in the presence of a sprain

lachman test

tests for integrity of ACL

lachman test positive sign

increased laxity or increased translation w lack of firm end-feel

lachman anatomical rationale

test places a stretch on ACL, which would reproduce sx (pain and/or instability) in the presence of a sprain; preferred test

anterior drawer test

tests for integrity of ACL (ligament laxity and quality of end-feel)

anterior drawer positive sign

greater anterior tibial displacement on affected side compared to uninvolved

anterior drawer anatomical rationale

test places stretch on ACL, which would reproduce sx (pain and/or instability) in the presence of a sprain; a lot of false negatives because HS guard tibia

posterior sag sign

tests for integrity of PCL

posterior sag sign positive sign

if tibial tuberosity is lower on one side compared to the other

posterior sag sign anatomical rationale

in the presence of a PCL tear, the tibial plateau would be translated posterior. this test is important to check prior to testing for an ACL injury to avoid a false positive

posterior drawer test

tests for integrity of PCL

posterior drawer positive sign

posterior displacement of tibia> 6mm

posterior drawer anatomical rationale

test places a stretch on PCL which would reproduce sx (pain and/or instability) in the presence of a sprain

ligament laxity tests for rotary instability (2-plane)

pivot shift test (lateral pivot shift test)

pivot shift test

tests for anterior-lateral instability

pivot shift test positive sign

increased tibial translation and ligamentous laxity, clunk or shift present, pain

pivot shift anatomical rationale

in the presence of antero-lateral instability (tear of ACL and LCL), the starting test position causes a subluxation of tibia on femur; going through the test motion results in a relocation ("shift") of tibia as fibers of ITB pull posteriorly on tibia

mcmurray test

tests for injury of medial or lateral meniscus

mcmurray test positive sign

clicking, thud, locking sensation, reproduction of pain

mcmurray anatomical rationale

test motion attempts to "catch" a tear in the meniscus between the joint surfaces of the tibial plateau and femoral condyle (add an axial compression too)

thessaly test

tests for injury of medial or lateral meniscus

thessaly positive sign

discomfort, sense of locking or catching per medial or lateral joint line

thessaly anatomical rationale

test places a compressive force between femoral condyles and tibial plateau, followed by a rotational force that attempts to "catch" a tear of the meniscus

hughston plica test

tests for abnormal medial plica

hughston plica positive sign

pain or palpable clicking

hughston plica anatomical rationale

test compresses plica between posterior surface of patella and medial femoral condyle, which reproduces comparable sign in presence of inflammation/irritation

eccentric step test

tests for patellofemoral pain syndrome

eccentric step positive sign

reports knee pain during test and poor quad control during step down

eccentric step anatomical rationale

test requires strong eccentric contraction of quads, which increases the compressive forces at the patellofemoral joint, reproducing pain

fairbank's (patellar) apprehension test

tests for excessive lateral tracking of patella or patellar tendon

fairbank's positive sign

observe for apprehension or pain; if pt tries to kick leg into extension to resist lateral force you apply

fairbank's anatomical rationale

test attempts to glide patella laterally which causes pt apprehension and reflexive quad contraction in the presence of joint instability/subluxation

noble compression test

tests for ITB syndrome

noble compression positive sign

if pt c/o severe pain over lateral epicondyle at around 30° and same pain during aggravating activities

noble compression anatomical rationale

compression of an inflamed ITB against the lateral femoral condyle reproduces pain as ITB rolls over lateral femoral condyle (changing tension in anterior and posterior fibers) at approximately 30° of flexion

modified stroke test

tests for knee joint effusion

modified stroke test positive sign

grade stroke test form 0-3+

grading for modified stroke test

0: no fluid produced at medial knee joint on down stroke
1+: small wave on medial side of downstroke
2+: effusion returns to medial side of after upstroke
3+: unable to move effusion from medial side when doing medial sided strokes

ligament injuries hx

well-localized area of pain (w area of injury); ACL injuries pain is more diffuse; rapid onset of swelling (<2 hr); deep continuous pain (increases when lig is stretched); with effusion, throbbing pain increases w WB + movement

chronic= joint instability (instead of more pain)

ligament injuries tests and measures

joint swelling; AROM and PROM limited; resisted tests strong and painfree; special tests will be (+), but acute injuries may be (-)

meniscal tears hx

MOI: rotation on flexed knee or hyper-flexion of knee when WB' "giving way" feeling; knee may lock (can't extend past 20-30° flexion); swelling is minimal or delayed

meniscal tears tests and measures

AROM and PROM limited; functional tests (squatting) w full flexion are limited; springy end feel; resisted tests strong and painfree; tenderness w palpation along joint line; (+) McMurray and Thessaly

chronic: weakness in quads/HS due to decreased use

patellofemoral pain syndrome (PFPS) general info

most common conditions at knee; adolescent women; associated with abnormal patellar tracking, abnormal knee joint mechanics

PFPS hx

insidious onset of anterior knee pain; bilat, exacerbated by activities that increase patellofemoral joint reaction forces (descending stairs, squatting, running) and prolonged knee flexion

PFPS tests and measures

biomechanical changes (increased Q angle, patella alta, pes planus, femoral anteversion); knee AROM and PROM WNL; functional tests (squatting and stairs) eccentric hip/quad control will reproduce sx; resisted tests may cause p! at 90°; glute med weakness; (+) eccentric step test; flexibility of quads, HS, ITB limited

patellar tendonitis/tendinosis (Jumper's knee) hx

insidious onset, h/o repeated jumping or running

patellar tendonitis/tendinosis (Jumper's knee) tests and measures

ROM WNL, p! reproduced w functional tests w jumping/landing; p! w resisted knee extensors, normal strength; tender w palpation along patellar tendon

iliotibial band friction syndrome (ITBFS)

when knee is fully extended, the band lies anterior to knee joint axis and when knee is flexed past 30°, the band rolls posterior to knee joint axis possibly resulting in an irritation of structures around ITB (bursa)

IT impingement syndrome

(ITB doesn't roll over lateral femoral condyle) different fibers of ITB are more taut during knee motions; repeated compression of lateral fat pad resulting from excessive femoral adduction/IR

ITBFS or IT impingement syndrome hx

overuse injury, insidious onset of lateral knee pain; aggravated by activities requiring repeated knee flex/ext (biking, hill climbing)

ITBFS or IT impingement syndrome tests and measures

posture may reveal increased hip adduction/IR and excessive genu valgus; weak glute med; pain over ITB; (+) ober's, (+) Noble's, (+) trendelenberg

OA (DJD) hx

insidious onset; c/o pain and morning stiffness throughout joint (diffuse pain); difficulty w ADLs (squatting, stairs, rising from seated)

OA tests and measures

varus deformity at knee; limited AROM and PROM and strength due to pain and disuse; tenderness over joint lines; audible and palpable crepitus is present

causes of OA

- metabolic syndrome
- lipid abnormalities
- obesity-related inflammation
- increased weight
- wear + tear
- injury
- cumulative force
- uric acid

pes anserinus bursitis hx

insidious onset of medial knee pain due to repetitive stress (long distance running)

pes anserinus bursitis tests and measures

tenderness w palpation distal to medial joint line

plica

extension of synovial membrane (found in some people, not everyone); medial plica causes sx

3 plica bands

suprapatellar, medial and infrapatellar

medial plica

originates along medial aspect of knee and courses obliquely toward and inserts into synovium covering the medial infrapatellar fat pad

plica hx

may be insidious or post-trauma; pain is intermittent and increases with activity and descending stairs; c/o locking or catching sensation

plica tests and measures

limited ROM and weakness due to pain and disuse; medial joint line may be tender to palpate

pediatric conditions

osgood-schlatter disease and sinding-larson-johanssen syndrome

osgood-schlatter disease

skeletally immature athletes due to repetitive stress to patellar tendon attachment; pain + tenderness at tibial tuberosity, aggravated by running and kicking motions; prominent tibial tuberosity

sinding-larsen-johanssen syndrome

similar to osgood-schlatter, but sx are located at inferior pole of patella

nerve roots that refer to knee

L2 and L3

L3

anterior medial aspect of knee (hip pathology may refer to this area of knee)

S1-S2

innervates posterior knee (may refer down posterior leg into foot)

osteosarcoma

found in end of long bones; teens, young adults, males

osteosarcoma signs + sx

pain and swelling in affected bone; night pain; lump; fx w/out trauma