Knee Injury-Baseball

Abstract

HISTORY: A 19yo male college baseball pitcher presented for acute onset left medial knee pain after attempting to carry a couch, at which time he twisted the knee into a valgus position and felt a painful pop. He had mild difficulty with weight bearing and swelling. He questioned whether he may have dislocated the kneecap with spontaneous reduction. He denied associated bruising, instability, hip or back pain. He denied prior knee injury. He did report mild chronic groin pain during pitching which was unchanged. PHYSICAL EXAMINATION: There was mild effusion about the left knee, with tenderness at the medial joint line and near the proximal origin of the MCL. There was pain with valgus stress, without clear laxity. Varus stress was non-provocative. Anterior and posterior drawer test were limited secondary to guarding. Lachman's test was equivocal. McMurray's test was positive for pain. Patellar apprehension was positive. Patellar grind was negative. Straight leg test was negative. Distal neurovascular exam was grossly intact. DIFFERENTIAL DIAGNOSIS: Lateral patellar dislocation/subluxation. ACL or MCL sprain/tear. Traumatic medial meniscus tear. Osteochondral lesion of the medial femoral condyle. Muscle or tendon sprain/tear. TEST AND RESULTS: Left knee X-ray was negative for fracture and showed normal alignment. Left knee MRI revealed nonspecific edema throughout the deep soft tissues of the posterior distal thigh and knee, most pronounced along the posteromedial aspect of the distal femoral metaphysis near the insertion of the adductor magnus tendon. Findings were suggestive of acute on chronic partial tearing/avulsion injury of the distal adductor magnus with an adjacent focus of mineralization consistent with underlying calcific tendinosis. The cruciate and collateral ligaments were intact. There were no findings suggestive of transient lateral patellar dislocation. FINAL WORKING DIAGNOSIS: Calcific tendinosis of the adductor magnus tendon, with superimposed traumatic avulsion injury/partial tearing TREATMENT AND OUTCOMES: The patient was allowed to weight bear as tolerated but was instructed to abstain from lower body exercise for 4 weeks. NSAIDs were used for pain relief as needed. He was referred to PT at 4 weeks with a focus on pitching mechanics.