Your Average Left Knee Pain With A Rare Incidental Finding

HISTORY: 39 y/o F w/ a PMHx of obesity presents with left knee pain. Three months prior, she tripped and twisted her left knee. Since then, she describes a left aching, anterior, generalized knee pain. Pain occurs intermittently and severity has fluctuated over time. Walking worsens the pain. OTC pain medications and rest provides relief. She’s been ambulatory since the injury. Denies tingling/numbness, mechanical symptoms, or instability. PHYSICAL EXAM: L lower extremity: Inspection: No erytheman; Palpation: Trace suprapatellar effusion, TTP over patella and medial/lateral joint lines; ROM: Full; Strength: 5/5 throughout; Sensation: Intact; Special tests: Negative (+) apprehension test, stable Varus and Valgus test at 0 and 30 degrees of flexion, (+) McMurray Test, (-) Lachman's Test DIFFERENTIAL DIAGNOSES: (1) Meniscal injury, (2) OA flare, (3) Chondromalacia patella, (4) Ligamentous injury, (5) Crystalline arthropathy TEST AND RESULTS: B/L knee x-ray AP Lateral: Multiple sessile and pedunculated osteochondromas arising from the distal femur and proximal tibia and fibula bilaterally. FINAL DIAGNOSIS: Meniscal tear w/ an incidental finding of Multiple Hereditary Exostoses TREATMENT AND OUTCOMES: Advised her to treat conservatively and provided her a script for physical therapy. Patient followed up with an orthopedic surgeon 1 month later. At this point, her knee pain improved. She was once again reassured that pain was not likely due to the multiple osteochondromas, but instead likely from an intra-articular injury. She was advised that it is unlikely for lesions to grow into something more aggressive because she already reached skeletal maturity. She was instructed to follow up as needed, however asked to return to clinic if she develops constant aching pain not relieved with OTC pain medication, persistent pain despite rest, and nighttime pain. She was given a referral to genetics for further evaluation since there was no known family history of this condition.