Introduction - Avulsion fracture of the anterior superior iliac spine (ASIS) is rare and occurring mainly among young teenagers during sports activities. We report a case of avulsion fracture of the ASIS during a school’s Sports Day.
Case Report – MH, a 15 year old male, presented to the Emergency Department (ED) complaining of right hip pain after winning the 100m sprint race. As soon as he crossed the finishing line, MH felt a popping sensation over his right hip and fell to the ground in pain. On arrival to the ED, MH was alert, in pain and unable to walk. He was placed supine on a trolley and managed in the semi critical area. He was hemodynamically stable with the pain score of 8/10. IV Ketorolac was administered for acute pain relief. Physical examination revealed localised tenderness over anterior aspect of the right pelvic region, with no swelling or deformity over the right hip joint. There was no limb length discrepancy of the right leg compared to the left. Active movements of right hip joint was restricted due to pain. Neurovascular examination was unremarkable; sensation was intact and the right leg was well perfused. Plain radiographs of the pelvis and right hip revealed avulsion fracture of the right ASIS. He was referred to Orthopaedics team and was planned for bedrest, adequate analgesia, and non-weight bearing ambulation. He was discharged home and reviewed in the outpatient clinic.
Discussion & Conclusion – Avulsion fracture of the ASIS is caused by forceful muscle contraction on a weaker and immature apophyseal cartilage in adolescence. During running activity, the sartorius muscle pulls the ASIS anteroinferiorly during maximum flexion of hip and extension of knee risking the avulsion of the pelvic apophyses. Although rarely encountered, avulsion fracture of the ASIS should always be suspected among athletic adolescents complaining of sudden localised hip pain with reduced range of movements.
avulsion fracture, anterior superior iliac spine