Knee Pain in a 7th Grade Runningback

Abstract

AUTHORS: Michael J. Bradburn, E. Ray Stewart, E. Lyle Cain AFFILIATION: The University of Alabama, Tuscaloosa, AL, Andrews Sports Medicine and Orthopaedic Center, Birmingham, AL TITLE: Knee pain in a 7th Grade Runningback CASE HISTORY: Patient is a 13-year-old male 7th grade runningback who sustained a left knee injury at practice. He reported running the football and dragging a defender who was holding onto the patients left leg. He felt a pop in his knee and reported immediate swelling. He was evaluated later that night at the Varsity football game and was referred to the sports medicine office in Tuscaloosa for evaluation. PHYSICAL EXAM: Inspection: non-weight bearing left lower extremity, assistance with crutches Mild ecchymosis, severe effusion, maximal tenderness: lateral joint line, medial patellar, moderate swelling Tests: left knee: negative Lachman’s, guarded medial and lateral McMurray’s. Negative valgus and varus stress, negative anterior and posterior drawer Range of motion left knee: painful active and passive range of motion, 45 degrees of flexion active and passive, 0 degrees extension active and passive Positive patellar apprehension on left Lower extremity strength is normal Lower extremity neurovascular exam is normal DIFFERENTIAL DIAGNOSIS #1: patellar subluxation #2: femoral condyle fracture #3: lateral collateral ligament sprain #4: lateral meniscus tear #5: femoral / tibial bone contusion TESTS AND RESULTS: X-ray Knee 4 views Left: avulsion fracture of lateral femoral condyle – minimally displaced MRI Left knee without contrast: popliteus tendon rupture with retraction. Edema surrounding ACL FINAL / WORKING DIAGNOSIS: Left popliteus tendon femoral avulsion DISCUSSION: Isolated popliteus tendon rupture is a rarely reported finding in the literature. The vast majority of popliteus tendon ruptures occur in combination with other ligamentous injuries specifically in the posterolateral structures of the knee. Generally, reported cases are treated non-operatively with a high rate of return to play at previous level. OUTCOME: Patient was evaluated by an orthopedic surgeon at Andrews Sports Medicine and Orthopaedic Center in Birmingham, AL and underwent arthroscopic left popliteus tendon repair RETURN TO ACTIVITY AND FOLLOW UP: After surgery the patient followed an ACL rehabilitation protocol, weight bearing as tolerated in a controlled motion brace, locked in extension for two weeks and began physical therapy after his initial post-operative appointment two weeks after surgery. At his 2-week post-operative appointment he could wean off crutches and weight bear as tolerated with his knee brace locked in extension. Physical therapy following ACL rehab protocol was initiated for the next 4 weeks, allowing for range of motion exercises out of the brace. After six weeks total he was released to return to full activities.