Medial Knee Pain - Recreational Swimmer

Abstract

HISTORY: A 42-year-old male physician and recreational swimmer presented with right knee pain. He had presented with right knee pain 1 year earlier after he slipped carrying a box, fell, and hyperflexed his knee. At that time he had minimal swelling, VMO pain, and was limited by pain with walking, squatting, or sitting with his knees bent. He complained of instability of the knee and tenderness to the medial joint line. MRI at that time revealed medial meniscus tear. He underwent arthroscopy for partial medial menisectomy of the posterior horn. Afterwards, his joint line pain resolved, but he continued to have pain localized to the VMO region with numbness and burning. Symptoms were constant, aching, and worsened by whip-kick motion with breast stroke, standing, knee bending, biking, and resting a portable computer on this area. He noted no skin rash, mottling, or temperature change. PHYSICAL EXAM Right knee with full ROM. Quad atrophy, including right VMO being slightly smaller than left. No palpable mass. No tenderness at VMO quadriceps or patellar tendon insertion, but tender over the VMO 1 inch from the insertion. Normal lower extremity reflexes. Decreased sensation along the medial knee from the joint line up to 10 cm proximal. Positive Tinel's sign at the adductor canal. Positive saphenous nerve stretch test. Lower extremity strength is 5/5 and equal. Plica band not palpable. No tenderness of the medial patellafemoral ligament, medial joint line, medial femoral condyle, or patella. Negative grind, Clark's sign, and lateral apprehension. Negative McMurray's. Lachman's and posterior drawer were normal. Varus and valgus stress were normal. Normal posterior tibialis pulse. Normal skin color and temperature. Arthroscope portal scars present, but not near the location of symptoms. DIFFERENTIAL DIAGNOSIS VMO tendinosis, saphenous nerve entrapment soft tissue or bone tumor (osteochondroma) lumbar radiculopathy (L3/L4) TESTS AND RESULTS Previous MRI knee – medial meniscus tear Knee Radiographs, 4 view – normal MRI thigh – normal FINAL WORKING DIAGNOSIS Saphenous Nerve Entrapment TREATMENT AND OUTCOMES Traditional PT and Augmented Soft Tissue Molibization 50% improvement, still restricted in activity of daily living. Steriod Injection at the Adductor Canal Marked immediate relief of symptoms, but minimal long-term improvement. Surgical consultation Neurontin/NSAIDS for conservative management. Some benefit, but patient elected saphenous nerve decompression. Operative findings included an area of serous fluid and pale area of nerve consistent with compression at the adductor canal. After the adductor canal was released his symptoms resolved.