KNEE EVALUATION

KNEE EVALUATIONS

The Knee JointKnee joint proper (tibiofemoral joint)TibiaFibulaFemurPatella

Patellofemoral jointFemoral condyles articulate with tibial plateaus

The Knee JointExtends to 180Hyperextension normalFlexes to 140With knee flexed 30 or >internal rotation 30 occursexternal rotation 45 occursThe PatellaSesamoid boneImbedded in quadriceps & patella tendonServes similar to a pulley for improving angle of pull (results in greater mechanical advantage in knee extension)

Surface Anatomy

Patella (A) Femur (B)Tibia (C,E tuberosity)Joint Line (D)Fibula (F)Gerdys TubercleInternal Knee Anatomy

Internal Knee Anatomy

Menisci

Bursae & Fat Pad of the Knee

Housemaids knee

Anatomy Soft TissueQuadriceps Rectus femorisVastus lateralisVastus intermediusVastus medialis (& oblique - VMO)Hamstrings Biceps femorisInserts primarily on fibula headSemitendinosusSemimembranosusInserts posteromedially on medial tibial condylePopliteal fossa

MusclesGracilis, Sartorius &SemitendinosusCommon attachmentPes Anscerine

Iliotibial BandGastrocnemius heads lateral & medial

Knee Movements

Screw Home MechanismLocking mechanism as the knee nears its final extension degreesAutomatic rotation of the tibia externally (approx. 10 degrees) during the last 20 degrees of knee extension

Femoral condyles are a different sizeMedial has larger surface area

The tibia glides anteriorly on the femur. As knee extends, the lateral femoral condyle expends its articular distance. The medial articulation continues to glide, resulting in external rotation of the tibia utilizing the lateral meniscus as the pivot point.

ACL & PCL are rotary guides

Forms a close-packed position for the knee jointHistoryMOI -Position of lower extremity at time of injury (?foot planted, knee extended)Previous historyPain (levels, types, descriptors)Unusual sounds/sensations pop, clicking, snappingChronic vs. acuteLocation of pain inside the kneeSurfaceShoesType of activity at time of injury Painful to walk up/down stairs; any clicking, catchingDid it swell immediately, slowly?Is the swelling located in the knee or in a pocket?

ObservationBilateral comparison Gait (limp, walking on toes, do they not want to extend knee, do they keep the knee stiff)Swelling (girth measurements)DiscolorationDeformity (squinting patellae, Frog-eyed patellae, Patella alta, Patella baja)Genu valgum, genu varum, recurvatumMusculature defined/mushy Q-angle

The quadriceps angle (Q-angle) is the angle formed between a line drawn through the tibial tuberosity and the center of the patella and another line drawn from the anterior superior iliac spine (ASIS) of the pelvis through the center of the patella.

PalpationTibia tibial plateau, tibial tuberosity, Gerdys TubercleFibula headMedial joint lineMedial collateral ligamentLateral joint lineLateral collateral ligamentWindowsMedial & Lateral femoral condyles & epicondylesPes anserine tendonSemitendinosus tendonPatella inferior polePatellar tendonQuadriceps muscle groupBiceps femoris tendonIliotibial bandPopliteal fossaGastrocnemius heads

Stress/Special TestsOn-field vs. Off-field evalCheck for fractures, blood, deformities, neurologicalValgus Stress Test MCLVarus Stress Test - LCLLachmans ACLAnterior Drawer ACLMcMurrays - meniscusAnterior Drawer Test(+) Test is increased anterior tibial translation over 6 mm(+) test indicates: ACL (anteromedial bundle)posterior lateral capsuleposterior medial capsuleMCL (deep fibers)ITBArcuate complexFalse (-) if only ACL is tornFalse (-) if there is swelling or hamstring spasmFalse (+) if there is a posterior sag sign present

Lachmans TestBest acute ACL testBest on field test(+) test is a mushy or empty end-feelFalse (-) if tibia is IR or femur is not properly stabilized

Posterior Drawer TestTests for posterior instabilityMake sure that there is no anterior translation prior to performing test(+) Test indicates:PCLArcuate ComplexPossibly ACL ???

Rubenstein, et al 1994 found posterior drawer test 90% sensitive for PCL injury (versus 58% for Quadriceps Active Test & 26% for Reverse Pivot Shift Test). Clinical exam on whole was 96% effective in detecting PCL dysfunctionGodfreys TestTests for posterior cruciate ligament damage (+) test is a posterior displacement of the tibial tuberosity

Valgus Stress TestAssesses medial instabilityMust be tested in 0 and 30(+) Test in 0MCL (superficial and deep)Posterior oblique ligamentPosterior medial capsuleACL/PCL(+) Test in 30MCL (superficial)Posterior oblique ligamentPCLPosterior medial capsuleGrading Sprains

McClure et al 1989 found poor intertester reliability on valgus stress test at 0 and 30 degrees using 3 PT to evaluate 50 patients26Miller et al 1998 used MRI to evaluate 65 patients with Grade III MCL sprains & found 45% also suffered bone bruising or microfracture. Bone injury with Grade III MCL is 50% as common as with Grade III ACL.Varus Stress TestAssesses lateral instabilityMust be tested in 0 and 20/30 flexion(+) Test in 0LCLPosterior Lateral CapsuleArcuate ComplexPCL/ACL(+) Test in 30LCLPosterior lateral capsuleArcuate complexGrading Sprains

Apleys Distraction TestTests for meniscal or ligamentous lesions(+) test is pain that is eliminated (meniscal injury), or pain that is increased (ligamentous)

Apleys Compression TestTests for meniscal lesions(+) test is increased pain during compression which may increase with rotation in either direction

Stress/Special TestsCheck for swellingSweep Test, Ballotable PatellaCheck ROM Elys TestCheck integrity of ligaments & joint stabilityValgus, Varus, Lachmans, Anterior/Posterior Drawer, Godfreys 90-90 Test, Posterior Sag Test, Crossover Test, Slocum Drawer Test, External Rotation Test, Pivot ShiftCheck integrity of meniscusMcMurrays, Apleys Compression/Distraction, Duck Walk, Bounce home Check integrity of patellaPatellar Apprehension, Q Angle, Clarkes Sign, Patellar glide, tilt, rotationCheck integrity of Iliotibial BandObers Test, Nobles Compression Test

Now What?? Crutches? Referral? RICE

Osgood-Schlatters Disease