KNEE EVALUATIONSKNEE EVALUATIONS

Quick FactsQuick Facts

Patellofemoral Joint Patellofemoral Joint (PFJ)(PFJ)

Variations in PFJ Variations in PFJ loading during OKC loading during OKC and CKC activitiesand CKC activities

PFJ loading increases:PFJ loading increases:– with increased flexion with increased flexion

in CKCin CKC– with increased with increased

extension in OKCextension in OKC

PFJ LoadingPFJ Loading Walking Walking

– 0.3 x body weight0.3 x body weight Ascending StairsAscending Stairs

– 2.5 x body weight2.5 x body weight Descending StairsDescending Stairs

– 3.5 x body weight3.5 x body weight SquattingSquatting

– 7 x body weight7 x body weight

HistoryHistory MOI -MOI -

– Position of lower extremity at time of injury Position of lower extremity at time of injury (?foot planted, (?foot planted, knee extended)knee extended)

Previous historyPrevious history Pain (levels, types, descriptors)Pain (levels, types, descriptors) Unusual sounds/sensations “pop, clicking, Unusual sounds/sensations “pop, clicking,

snapping”snapping” Chronic vs. acuteChronic vs. acute Location of pain “inside the knee”Location of pain “inside the knee” SurfaceSurface ShoesShoes Type of activity at time of injury Type of activity at time of injury Painful to walk up/down stairs; any clicking, catchingPainful to walk up/down stairs; any clicking, catching Did it swell immediately, slowly?Did it swell immediately, slowly? Is the swelling located in the knee or in a pocket?Is the swelling located in the knee or in a pocket?

ObservationObservation

Bilateral comparison Bilateral comparison Gait (limp, walking on toes, do they not Gait (limp, walking on toes, do they not

want to extend knee, do they keep the want to extend knee, do they keep the knee stiff)knee stiff)

Swelling (girth measurements)Swelling (girth measurements) DiscolorationDiscoloration Deformity (squinting patellae, “Frog-eyed” Deformity (squinting patellae, “Frog-eyed”

patellae, Patella alta, Patella baja)patellae, Patella alta, Patella baja) Genu valgum, genu varum, recurvatumGenu valgum, genu varum, recurvatum Musculature – defined/mushy Musculature – defined/mushy

Q-angleQ-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.

Q-angleQ-angle

Knee in extensionKnee in extension– Normal males: 13 degreesNormal males: 13 degrees– Normal females: 18 degrees Normal females: 18 degrees

Knee in 90 degrees flexionKnee in 90 degrees flexion– Both genders: 8 degreesBoth genders: 8 degrees

Structural AlignmentStructural Alignment

Genu Varum (Bowlegged)Genu Varum (Bowlegged) Genu Valgum (knock kneed)Genu Valgum (knock kneed)

Boney PalpationBoney Palpation

TibiaTibia– Tibial tuberosityTibial tuberosity– Tibial Condyles (medial + Tibial Condyles (medial +

lateral)lateral) FibulaFibula

– HeadHead Medial joint lineMedial joint line Medial collateral ligamentMedial collateral ligament Lateral joint lineLateral joint line Lateral Collateral LigamentLateral Collateral Ligament ““Windows”Windows” Medial & Lateral Femoral Medial & Lateral Femoral

EpicondylesEpicondyles

Pes AnserinePes Anserine HamstringsHamstrings

– Semitendinosus tendonSemitendinosus tendon– SemimebranosusSemimebranosus– Biceps femoris tendonBiceps femoris tendon

Quadriceps muscle groupQuadriceps muscle group– Rectus FemorisRectus Femoris– Vastus LateralisVastus Lateralis– Vastus IntermediusVastus Intermedius– Vastus Medialis ObliqueVastus Medialis Oblique

Biceps femoris tendonBiceps femoris tendon Iliotibial bandIliotibial band Popliteal fossaPopliteal fossa Gastrocnemius headsGastrocnemius heads Patella Patella Patellar tendonPatellar tendon

Boney PalpationBoney Palpation

TibiaTibia– Tibial tuberosityTibial tuberosity– Tibial Condyles (medial + lateral)Tibial Condyles (medial + lateral)

FibulaFibula– HeadHead

Medial & Lateral Femoral EpicondylesMedial & Lateral Femoral Epicondyles PatellaPatella

Surface AnatomySurface Anatomy

Patella (A) Patella (A) Femur (B)Femur (B) Tibia (C,E – Tibia (C,E –

tuberosity)tuberosity) Joint Line (D)Joint Line (D) Fibula (F)Fibula (F)

Boney AnatomyBoney Anatomy

Bony AnatomyBony Anatomy– Lower LegLower Leg

TibiaTibia– Bears most of the Bears most of the

weightweight

FibulaFibula– Attachment place for Attachment place for

muscles & ligamentsmuscles & ligaments

– Upper LegUpper Leg FemurFemur

– PatellaPatella

PatellaPatella

Sesamoid boneSesamoid bone Imbedded in quadriceps & patella Imbedded in quadriceps & patella

tendontendon Serves similar to a pulley for Serves similar to a pulley for

improving angle of pull (results in improving angle of pull (results in greater mechanical advantage in greater mechanical advantage in knee extension)knee extension)

Tendons + LigamentsTendons + Ligaments Medial joint lineMedial joint line Medial collateral ligamentMedial collateral ligament Lateral joint lineLateral joint line Lateral Collateral LigamentLateral Collateral Ligament ““Windows”Windows” Pes AnserinePes Anserine

– Semitendinosus tendonSemitendinosus tendon– Gracilis tendonGracilis tendon– Sartorius tendonSartorius tendon

Semimebranosus tendonSemimebranosus tendon Biceps femoris tendonBiceps femoris tendon Quadriceps TendonQuadriceps Tendon Biceps femoris tendonBiceps femoris tendon Iliotibial bandIliotibial band Patellar tendonPatellar tendon

Internal Knee AnatomyInternal Knee Anatomy

Internal Knee AnatomyInternal Knee Anatomy

Medial Medial MeniscusMeniscus

Lateral Lateral MeniscusMeniscus

Anterior Anterior Cruciate Cruciate LigamentLigament

Posterior Posterior Cruciate Cruciate LigamentLigament

Articular Articular CartilageCartilage

MenisciMenisci

Bursae & Fat Pad of the Bursae & Fat Pad of the KneeKnee

Cruciate Ligament Cruciate Ligament MovementMovement

Anatomy – Soft TissueAnatomy – Soft Tissue

Quadriceps – Quadriceps – – Rectus femorisRectus femoris– Vastus lateralisVastus lateralis– Vastus intermediusVastus intermedius– Vastus medialis Vastus medialis

oblique oblique Hamstrings – Hamstrings –

– Biceps femorisBiceps femoris– SemitendinosusSemitendinosus– SemimembranosusSemimembranosus

PopliteusPopliteus– Popliteal fossaPopliteal fossa

Gastrocnemius + Gastrocnemius + SoleusSoleus

Tibialis AnteriorTibialis Anterior

MusclesMuscles

Quick FactsQuick Facts

Tibiofemoral Joint (TFJ)Tibiofemoral Joint (TFJ) Normal ROMNormal ROM

– Flexion 135-140 degreesFlexion 135-140 degrees– Extension 0 degreesExtension 0 degrees

Closed Pack PositionClosed Pack Position– Full extension with ERFull extension with ER

Loose Packed PositionLoose Packed Position– 25 degrees of flexion25 degrees of flexion

Knee MovementsKnee Movements

Screw Home MechanismScrew Home Mechanism

Locking mechanism as the knee nears its final extension degreesLocking mechanism as the knee nears its final extension degrees– Automatic rotation of the tibia externally (approx. 10 degrees) during the last Automatic rotation of the tibia externally (approx. 10 degrees) during the last

20 degrees of knee extension20 degrees of knee extension

Femoral condyles are a different sizeFemoral condyles are a different size– Medial has larger surface areaMedial has larger surface area

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

ACL & PCL are rotary guidesACL & PCL are rotary guides

Forms a close-packed position for the knee jointForms a close-packed position for the knee joint

Special TestsSpecial Tests Myotomes and DermatomesMyotomes and Dermatomes Valgus Stress testValgus Stress test Varus Stress TestVarus Stress Test Tinel TestTinel Test Apley Apley McMurrayMcMurray Anterior DrawerAnterior Drawer LachmansLachmans Posterior DrawerPosterior Drawer Godfrey’s 90/90Godfrey’s 90/90 Posterior SagPosterior Sag Patellar Apprehension TestPatellar Apprehension Test Clark’s SignClark’s Sign

Stress/Special TestsStress/Special Tests

Check for swellingCheck for swelling Check ROM Check ROM Check integrity of ligaments & Check integrity of ligaments &

joint stabilityjoint stability– Valgus, Varus, Lachman’s, Anterior/Posterior Valgus, Varus, Lachman’s, Anterior/Posterior

Drawer, Godfrey’s 90-90 Test/Posterior Sag Test, Drawer, Godfrey’s 90-90 Test/Posterior Sag Test,

Check integrity of meniscusCheck integrity of meniscus– McMurray’s, Apley’s Compression/Distraction, Duck McMurray’s, Apley’s Compression/Distraction, Duck

Walk, Walk,

Check integrity of patellaCheck integrity of patella– Patellar Apprehension,Patellar Apprehension, Q Angle, Clarke’s Sign, Q Angle, Clarke’s Sign,

Special TestsSpecial Tests

Anatomy of the ACLAnatomy of the ACL

3 strands3 strands Anterior medial tibia Anterior medial tibia

to posterior lateral to posterior lateral femurfemur

Prevent anterior Prevent anterior tibial displacement tibial displacement on femuron femur

Secondarily, Secondarily, prevents prevents hyperextension, hyperextension, varus & valgus varus & valgus stressesstresses

Biomechanics of the ACLBiomechanics of the ACL Most injuries occur in Most injuries occur in

Closed Kinetic ChainClosed Kinetic Chain Least stress on ACL Least stress on ACL

between 30-60 between 30-60 degrees of flexiondegrees of flexion

Anteromedial bundle Anteromedial bundle tight in flexion & tight in flexion & extensionextension

Posterior lateral Posterior lateral bundle tight only in bundle tight only in extensionextension

ACL TearsACL Tears

Most common mechanismsMost common mechanisms– Contact:Contact:

CKC with foot ER w/ valgus stressCKC with foot ER w/ valgus stress HyperextensionHyperextension direct hit on the posterior tibiadirect hit on the posterior tibia

– Non-Contact: Non-Contact: Most commonMost common Due to sudden decelerationDue to sudden deceleration Sudden landing, cutting, or Sudden landing, cutting, or

pivotingpivoting

Patient will c/o “buckling” or Patient will c/o “buckling” or “giving away”, typically will hear “giving away”, typically will hear and/or feel a “pop”and/or feel a “pop”

Diagnostic ImagingDiagnostic Imaging

Why perform an MRI after ACL injury?

Anterior LachmansAnterior Lachmans Position:Position:

– SupineSupine– Knee flexed to 20 – 30 Knee flexed to 20 – 30

degreesdegrees– Proximal hand on Femur Proximal hand on Femur

above the patella, distal above the patella, distal hand on Tibia just below hand on Tibia just below Tibial TuberosityTibial Tuberosity

Action:Action:– Apply anterior force to the Apply anterior force to the

tibia with the distal hand tibia with the distal hand while stabilizing the femur while stabilizing the femur with the proxmial handwith the proxmial hand

Positive Findings:Positive Findings:– Anterior Cruciate Ligament Anterior Cruciate Ligament

SprainSprain Joint opening upJoint opening up

Anterior DrawerAnterior Drawer Position:Position:

– Hip flexed to 45Hip flexed to 45oo; knee ; knee flexed @ 90flexed @ 90oo

– Foot on table in neutralFoot on table in neutral– Examiner sits on foot w/ B Examiner sits on foot w/ B

hands behind the subject’s hands behind the subject’s proximal tibia and thumbs proximal tibia and thumbs on the tibial plateauon the tibial plateau

Action:Action:– Apply anterior force to the Apply anterior force to the

proximal tibia, feeling the proximal tibia, feeling the hamstrings for tightnesshamstrings for tightness

Positive FindingsPositive Findings– Anterior Tibial DisplacementAnterior Tibial Displacement– Anterior Cruciate Ligament Anterior Cruciate Ligament

SprainSprain

PCL BiomechanicsPCL Biomechanics

Functions:Functions:– Primary stabilizer of the Primary stabilizer of the

knee against posterior knee against posterior movement of the tibia movement of the tibia on the femuron the femur

– Prevents flexion, Prevents flexion, extension, and extension, and hyperextensionhyperextension

Taut at 30 degrees of Taut at 30 degrees of flexionflexion– posterior lateral fibers posterior lateral fibers

loose in early flexionloose in early flexion

Posterior Cruciate Posterior Cruciate LigamentLigament

Two bundlesTwo bundles– Anterolateral, taut in flexionAnterolateral, taut in flexion– Posteromedial, taut in extensionPosteromedial, taut in extension

Orientation prevents posterior Orientation prevents posterior motion of tibiamotion of tibia

PCL larger & stronger than ACLPCL larger & stronger than ACL– CSA 120-150% largerCSA 120-150% larger– CSA AL 2x PMCSA AL 2x PM

Consider associated role of Consider associated role of posterolateral complex when posterolateral complex when discussing PCLdiscussing PCL– LCLLCL– Popliteus ComplexPopliteus Complex– Arcuate LigamentArcuate Ligament– Posterior Lateral CapsulePosterior Lateral Capsule

PCL InjuriesPCL Injuries

Very rare in athletics, Very rare in athletics, usually due to MVAusually due to MVA– Due to hyperextension, Due to hyperextension,

hyper-flexion, or the tibia hyper-flexion, or the tibia being forced posteriorly on being forced posteriorly on the femurthe femur

– Only 33% related to sportsOnly 33% related to sports Isolated PCL Injuries Isolated PCL Injuries

unusualunusual– Assess other ligamentsAssess other ligaments

Avulsion InjuriesAvulsion Injuries Mid-Substance TearsMid-Substance Tears

Posterior Drawer TestPosterior Drawer Test Position:Position:

– Hip flexed to 45Hip flexed to 45oo; knee ; knee flexed @ 90flexed @ 90oo

– Foot on table in neutralFoot on table in neutral– Examiner sits on foot w/ B Examiner sits on foot w/ B

hands behind the subject’s hands behind the subject’s proximal tibia and thumbs proximal tibia and thumbs on the tibial plateauon the tibial plateau

Action:Action:– Apply posterior force to Apply posterior force to

the proximal tibiathe proximal tibia Positive FindingsPositive Findings

– Posterior Tibial Posterior Tibial DisplacementDisplacement

– Posterior Cruciate Posterior Cruciate Ligament SprainLigament Sprain

Godfrey’s 90/90TestGodfrey’s 90/90Test

Position:Position:– Hip flexed to 90Hip flexed to 90oo; knee ; knee

flexed @ 90flexed @ 90oo

– Examiner holds onto Examiner holds onto both heelsboth heels

Action:Action:– Look for posterior Look for posterior

translation of the tibiatranslation of the tibia Positive FindingsPositive Findings

– Displacement of the Displacement of the TibiaTibia

– Posterior Cruciate Posterior Cruciate Ligament SprainLigament Sprain

Posterior Sag TestPosterior Sag Test

Position:Position:– Lie on table Knee flexed to Lie on table Knee flexed to

9090oo; Hip flexion 45; Hip flexion 45oo

Action:Action:– Subject actively flexes Subject actively flexes

Quads while hip remains in Quads while hip remains in 4545oo

– Look for a posterior Look for a posterior translation of the Tibia in translation of the Tibia in relation to the Femurrelation to the Femur

Positive findings:Positive findings:– Posterior Cruciate Posterior Cruciate

Ligament SprainLigament Sprain

MCL BiomechanicsMCL Biomechanics Primary role is to Primary role is to

prevent against a prevent against a valgus force and valgus force and external rotation of external rotation of the tibiathe tibia

Throughout Full Range Throughout Full Range of Motion:of Motion:– Both fibers are taut in Both fibers are taut in

full extensionfull extension– Anterior fibers are taut Anterior fibers are taut

in flexionin flexion– Posterior fibers are taut Posterior fibers are taut

in mid rangein mid range

MCL SprainsMCL Sprains

Typically due to valgus forces in CKCTypically due to valgus forces in CKC– Foot typically in neutral or externally rotatedFoot typically in neutral or externally rotated

Most frequently injured ligament in the kneeMost frequently injured ligament in the knee Usually no joint effusion unless deep portion Usually no joint effusion unless deep portion

affected since primarily located outside the joint affected since primarily located outside the joint capsulecapsule

Valgus Stress TestValgus Stress Test Position:Position:

– Knee @ 0Knee @ 0o o and knee @ 30and knee @ 30oo

– Proximal hand on Lateral Proximal hand on Lateral joint linejoint line

– Distal hand on the lower Distal hand on the lower legleg

Action:Action:– Apply medial force to Apply medial force to

lateral joint line; and lateral joint line; and lateral force to distal tibialateral force to distal tibia

Positive FindingsPositive Findings– Medial Collateral Ligament Medial Collateral Ligament

SprainSprain

LCL BiomechanicsLCL Biomechanics Primary role is to Primary role is to

protect from varus protect from varus forces and external forces and external rotation of the tibia, rotation of the tibia, assists in 2assists in 2° restraint ° restraint for anterior and for anterior and posterior tibial posterior tibial translationtranslation

Throughout Range of Throughout Range of motion:motion:– Is taut during extensionIs taut during extension– Loose during flexion Loose during flexion

Especially after 30Especially after 30° of ° of flexionflexion

LCL SprainsLCL Sprains

Typically due to varus forces, especially in CKC position Typically due to varus forces, especially in CKC position with leg adducted and tibia internally rotatedwith leg adducted and tibia internally rotated

Usually occur during contact sportsUsually occur during contact sports Typically has limited joint effusion since it is located Typically has limited joint effusion since it is located

outside of the joint capsuleoutside of the joint capsule

Varus Stress TestVarus Stress Test Position:Position:

– Knee @ 0Knee @ 0o o and knee @ 30and knee @ 30oo

– Medial hand on Medial Medial hand on Medial joint linejoint line

Action:Action:– Apply lateral force to Apply lateral force to

medial joint line; and medial joint line; and medial force to distal tibiamedial force to distal tibia

Positive FindingsPositive Findings– Lateral Collateral Lateral Collateral

Ligament SprainLigament Sprain

Meniscal FunctionsMeniscal Functions Deepens the articulation Deepens the articulation

and fills the gaps that and fills the gaps that normally occur during the normally occur during the knee’s articulationknee’s articulation

Primary FunctionsPrimary Functions– Load distributionLoad distribution– Joint StabilityJoint Stability– Shock AbsorptionShock Absorption

Secondary FunctionsSecondary Functions– Joint LubricationJoint Lubrication– Articular Cartilage NutritionArticular Cartilage Nutrition– Proprioceptive FeedbackProprioceptive Feedback

Mechanism of InjuryMechanism of Injury

TraumaTrauma– CompressionCompression– Rotational ForceRotational Force– Valgus ForceValgus Force– Usually Combination of Usually Combination of

ForcesForces Degenerative ChangesDegenerative Changes

– Greater than 30 years oldGreater than 30 years old– No PMHX requiredNo PMHX required– Often due to MOI that Often due to MOI that

“seemed harmless” at time“seemed harmless” at time

Noyes, 2002 states 60% of meniscal injuries associated with ACL injury

ApleyApley CompressionCompression

– Position:Position: ProneProne Knee flexed to 90Knee flexed to 90oo ; ;

foot dorsiflexedfoot dorsiflexed– Action:Action:

Stabilize the femur Stabilize the femur with examiner’s kneewith examiner’s knee

Push down on Push down on ankle/lower leg and ankle/lower leg and rotaterotate

– Positive findings:Positive findings: Pain = Meniscus Pain = Meniscus No Pain = Ligament No Pain = Ligament

involvementinvolvement

DistractionDistraction– Position:Position:

ProneProne Knee flexed to 90Knee flexed to 90oo ; ;

foot dorsiflexedfoot dorsiflexed– Action:Action:

Stabilize the femur Stabilize the femur with examiner’s kneewith examiner’s knee

Pull up on ankle/lower Pull up on ankle/lower leg and rotateleg and rotate

– Positive findings:Positive findings: No pain = Meniscus No pain = Meniscus Pain = Ligament Pain = Ligament

involvementinvolvement

McMurrayMcMurray Position:Position:

– SupineSupine– Examiner’s standing with distal hand grasping the Examiner’s standing with distal hand grasping the

subject’s heel; proximal hand on subject’s knee with subject’s heel; proximal hand on subject’s knee with fingers palpating the medial and lateral joint linesfingers palpating the medial and lateral joint lines

Action:Action:– Knee fully flexed, externally rotate the tibia and Knee fully flexed, externally rotate the tibia and

introduce a valgus force and extend the kneeintroduce a valgus force and extend the knee Medial MeniscusMedial Meniscus

– Repeat with internal rotation of the tibia and Varus force.Repeat with internal rotation of the tibia and Varus force. Lateral MeniscusLateral Meniscus

Positive Findings:Positive Findings:– ““Clicking” indicates a Meniscal TearClicking” indicates a Meniscal Tear

Medial side = medial meniscusMedial side = medial meniscus Lateral side = lateral meniscusLateral side = lateral meniscus

Unhappy TriadUnhappy Triad

MCL, ACL, Medial MCL, ACL, Medial MeniscusMeniscus

Typically due to a valgus Typically due to a valgus force with the foot plantedforce with the foot planted

PFJ BiomechanicsPFJ Biomechanics During extension, During extension,

patella glides craniallypatella glides cranially During flexion, patella During flexion, patella

glides caudallyglides caudally Patellar compressionPatellar compression

– OKC greatest at end OKC greatest at end range (final 30 degrees)range (final 30 degrees)

– increases in CKC after increases in CKC after 30 degrees of flexion30 degrees of flexion

Patellofemoral Pain Patellofemoral Pain SyndromeSyndrome

General term to describe General term to describe anterior knee painanterior knee pain

Caused by a variety of factors:Caused by a variety of factors: Signs & Symptoms:Signs & Symptoms:

– Poorly localized PainPoorly localized Pain– Little to no swellingLittle to no swelling– Pt. Tenderness under lateral patellaPt. Tenderness under lateral patella– Insidious onsetInsidious onset

Clark’s Sign (Patellar Grind Clark’s Sign (Patellar Grind Test)Test)

Position:Position:– Patient is lying supine w/ knee extendedPatient is lying supine w/ knee extended– Examiner places the web space of the thumb on the Examiner places the web space of the thumb on the

superior border of the patellasuperior border of the patella Action:Action:

– Subject contracts the Quads while the examiner Subject contracts the Quads while the examiner applies downward and inferior pressure to the applies downward and inferior pressure to the patellapatella

Positive Finding:Positive Finding:– Pain with movement of patella or inability to Pain with movement of patella or inability to

complete testcomplete test– Chondromalacia patella or patellar femoral Chondromalacia patella or patellar femoral

syndromesyndrome

Patellar Apprehensive TestPatellar Apprehensive Test

Position:Position:– Patient is supine and relaxedPatient is supine and relaxed

Action:Action:– Examiner grabs patella and pushes it in all 4 Examiner grabs patella and pushes it in all 4

waysways Superior / InferiorSuperior / Inferior Lateral / MedialLateral / Medial

Positive Findings:Positive Findings:– Patient ApprehensionPatient Apprehension– Excessive Movement in one directionExcessive Movement in one direction– Dislocating PatellaDislocating Patella

Osgood-Schlatter’s DiseaseOsgood-Schlatter’s Disease

Housemaid’s kneeHousemaid’s knee