Hip pain in an adolescent after injury while playing football

A 15 year old boy presented to the emergency department with left hip pain that first occurred while playing football. The exact mechanism of injury was unclear, but he thought that he may have “kicked the ground rather than the ball.” He was unable to continue playing because of pain on weight bearing, and he was forced to limp from the field with assistance. He arrived at hospital after a couple of hours. His developmental progress and medical history were normal, with no previous hip problems reported. On examination he was constitutionally well. Tenderness of the left hemipelvis was noted on palpation. He was reluctant to perform any active movement of the hip or bear his weight, and he was unable to perform a straight leg raise. Passive movements (including rotation) caused generalised tenderness, with passive hip extension causing the most discomfort. Examinations of both his back and left knee were unremarkable. Anterioposterior radiography of the pelvis was performed (fig 1⇓). Fig 1 Anterioposterior radiograph of the pelvis in a 15 year old boy ### 1 Given the history, what is the differential diagnosis? #### Short answer A simple muscular strain is the most likely diagnosis given the history. Hip dislocation, slipped capital femoral epiphysis, pelvic and femoral fractures, and infection are all potentially serious causes of pelvic pain in adolescents. Neoplastic and rheumatological disorders also merit consideration. #### Long answer All types of fracture pattern could present in this manner—growth plate injuries, apophyseal avulsion fractures, non-physeal fractures, pathological fractures, femoral neck fractures, and stress fractures. Dislocation of the hip is unlikely given the relatively innocuous mechanism of injury. Non-physeal injuries, such as femoral neck fracture, are usually caused by …