Knee Pain and the Knee Exam

February 21, 2013Kate Lupton, MD

History

• Joint(s) involved• Functional limitations• ?Trauma/Injury -> Mechanism• Acute onset vs. slowly progressive• Prior problems with area• Systemic signs and symptoms

Principles of the MSK Exam

• Good exposure (clothing removed, in gown)

• LOOK• FEEL• MOVE• SPECIAL TESTS

LOOK

LOOK

• Alignment/Posture – – “Ankles together” – look at knees (genu valgus/varus)– “Ankles shoulder width apart” – look at arches (pes

planus/cavus, tibial torsion)– “Turn around” – look at heel alignment, back of knees

– heel valgus/varus, Baker’s cyst

• Gait – heel/toe walk, squat• Knee – “SEADS” = swelling, erythema, atrophy,

deformity, scars

LOOK

FEEL

• Find point maximal tenderness• ?Reproduce sx• Effusion – patellar ballotment• Patella – check mobility, tenderness under

lateral, medial, inferior facets. Apprehension – knee flexed to 20°, laterally deviate patella. If involuntary quad contraction -> positive sign

• Joint line – palpate MCL, LCL, meniscal cyst• Posterior knee – muscle insertions, Baker cyst

FEEL

FEEL

Patellar Ballotment• Flex knee• Hand on supra-patellar

pouch, push down toward patella

• Push down perpendicularly on center of patella

• If effusion – patella floats and “bounces” back when pushed

FEEL

Joint line palpation• slightly flex knee• Run fingers up tibia, will

“drop” into joint line• Can flex/extend to

confirm• Feel along medial and

lateral joint lines

MOVE

• Active and passive flexion/extension• ROM – flex to 130-150°, extend 0-15°• Hyperflexion, hyperextension• Crepitus – hand over patella while

flexing/extending• Resisted active flexion/extension• Neurovascular exam – motor, sensory, reflexes,

cap refill, pulses• Hip/back screen – log roll leg, straight leg raise

MOVE

SPECIAL TESTS

• Menisci – joint line tenderness, hyperflexion/extension, McMurray

• Ligaments – Lachman, drop Lachman, anterior/posterior drawer, posterior sag, valgus/varus stress

SPECIAL TESTS

SPECIAL TESTS - Menisci

Joint line palpation• slightly flex knee• Run fingers up tibia, will

“drop” into joint line• Can flex/extend to

confirm• Feel along medial and

lateral joint lines

SPECIAL TESTS - MenisciMcMurray’s – medial

meniscus• Opposite hand grasps knee

w/ fingers on medial JL (L hand grasps R knee)

• Same hand grasps heel (R hand grasps R heel), flex knee past 90°

• Turn ankle so foot and knee point outward (heel toward compartment tested)

• Slowly extend knee to 90°, if positive test, feel palpable thud. Pain localizing to JL is also positive sign

• Sens 29%, spec 95%

SPECIAL TESTS - MenisciMcMurray’s – lateral meniscus• Opposite hand grasps knee

w/ fingers on medial JL (L hand grasps R knee)

• Same hand grasps heel (R hand grasps R heel), flex knee

• Turn ankle so foot and knee point inward (heel toward compartment tested)

• Slowly extend knee to 90°, if positive feel palpable thud. Pain localizing to JL is also positive sign

• Sens 29%, spec 95%

SPECIAL TESTS - Ligaments

Medial Collateral Ligament • Flex knee to 20-30°• One hand on inner

calf/ankle• Push inward (valgus

stress) on lateral knee while applying outward stress with hand on calf/ankle

• Positive test = joint laxity

SPECIAL TESTS - Ligaments

Lateral Collateral Ligament • Flex knee to 20-30°• One hand on outer

calf/ankle• Push outward (varus

stress) on medial knee while applying inward stress with hand on calf/ankle

• Positive test = joint laxity

SPECIAL TESTS - LigamentsLachman’s (ACL)• patient supine, knee at 20-

30° flexion• Fix femur with one hand, lift

tibia forward with other hand (force perpendicular to plane of tibia)

• Slight external rotation of foot

• Anterior force should be applied near posteromedial aspect of proximal tibia

• Positive if tibia subluxes anteriorly and concavity of patellar tendon becomes convex

• Sens 82%, spec 97%

SPECIAL TESTS - LigamentsDrop Lachman (ACL)• Better for big legs/small

hands• Patient lies with leg

abducted off side of table, flexed 25°

• Stabilize foot between examiner’s legs

• Hold femur on table with one hand

• Use opposite hand to anteriorly sublux tibia

• More sensitive than Lachman as less hamstring recruitment

SPECIAL TESTS - Ligaments

Posterior Sag (PCL)• Patient lies supine, hip

flexed to 45° and knees to 90°

• Positive if absence of tibial tubercle prominence due to posterior shift of tibia

SPECIAL TESTS - Ligaments

Posterior Drawer (PCL)• Patient supine with knee

bent to 90°• Sit on foot, grasp below

knee with both hands, thumbs on anterior tibial tuberosity

• Push backward – if intact PCL, feel distinct endpoint

• If PCL disrupted, tibia feels unrestrained in posterior translocation

SPECIAL TESTS – patellofemoral pain and chondromalacia

• Slightly flex knee• Push down on patella

with both thumbs – pain if chondromalacia

• Hold patella in place with hand, direct patient to contract quadriceps, forcing inferior surface of patella onto femur – elicits pain if chondromalacia

Many thanks to:

Anthony Luke, MD – UCSFCharlie Goldberg, MD – UCSD