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 – Gait – heel/toe walk, squat “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 - Menisci McMurray’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 McMurray’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 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 - 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