Knee Pain That Wasn’t in a Twin Cities Marathon Finisher

Abstract

HISTORY: A 53 yo male marathon runner presented to the medical tent after finishing race complaining of R lat knee & ant distal thigh pain. His R knee “gave out” 30 m from finish line. He hopped on his L leg to finish the race (3 hr 45 min). He had completed several marathons without incident. He trained for 22 wk, but had 6 wk of self-diagnosed R “IT band pain” leading up to the race. He described his pain as starting in the hip & radiating down the thigh to his knee. He did not seek medical attention for this pain. He had no past hx of stress fx, disordered eating, or tobacco use. Takes Vit D & calcium daily & drinks milk regularly. PHYSICAL EXAM:Gait: Unable to bear weight. Inspection: (+) spasm of R quadriceps. No swelling, erythema, ecchymosis or atrophy. Palpation: Tender along groin, greater trochanter, & Gerdy’s tubercle. No effusion of knee or hip joint. Quad tendon-without noticeable defect. Knee non-tender. Active ROM: Unable to actively flex hip or elevate leg. SLR painful. Passive ROM & Strength: Hip & knee - limited by pain, able to fire quad against gravity & slide foot along bed in extension. Ligament Stability: Knee - Varus/valgus testing, ant & post drawer, & Lachman’s firm end points, R Lachman “looser” than L; inferior traction on R lower leg while in knee extension provided “instant pain relief” per patient.Leg Position: After pain relieved, R leg was externally rotated & shortened. DIFFERENTIAL DIAGNOSIS: Femur Fx (Femoral neck, head, or shaft) Quad tendon strain/rupture Patellar tendon rupture ITB rupture ACL sprain/rupture TESTS AND RESULTS: Imaging: Xray Femur: Comminuted fracture of femoral diaphysis with displacement & angulation. CT Scan Femur: Comminuted fx of femoral diaphysis centered proximal to middle-distal 1/3 junction with angulation & displacement. No underlying lytic lesion. R femoral neck synovial herniation pit described as normal variant, but also associated with femoral acetabular impingement. Labs: Testosterone: 726 ng/dl (nrl) Vit D: 38 ng/ml (nrl) FINAL/WORKING DIAGNOSIS: R Comminuted midshaft femur fracture atop a stress fx in marathon finisher TREATMENT AND OUTCOMES: ED transport by private vehicle Orthopedic surgeon determined surgery indicated Surgical procedure - locked intramedullary nail implanted Post Op: WBAT & ROM of hip & knee as tolerated DEXA scan scheduled