Knee Pain and the Knee Exam February 21

Knee Pain and the Knee Exam February 21, 2013 Kate 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, Mc. Murray • 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 - Menisci Mc. Murray’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 - Menisci Mc. Murray’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 - Ligaments Lachman’s (ACL) • patient supine, knee at 2030° 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 - Ligaments Drop 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 – UCSF Charlie Goldberg, MD – UCSD