LAUSR

Introduction Pelvic avulsion fractures are almost exclusively caused by strong contractions or elongations of the attached muscles during sports participation in young adolescents. These fractures mostly occur when muscle strength increases and ossific nuclei have yet to fuse at pelvic tuberosities (1,2). Apophyseal avulsion fractures in the general population are rare but among adolescent elite athletes with pain in the pelvic area, the overall prevalence can be as high as 16.4% (3). Most patients can be treated conservatively and can return to sport within 6 wk to 6 months after avulsion (1,2). The complication rate across all pelvic avulsion fractures is around 17% where possible complications include nonunion, malunion, persistent pain, functional impairment, and impingement (1). These complications can sometimes necessitate surgical correction (1,4). Multiple locations and muscle groups in the pelvic region can be involved. Recent literature shows the anterior inferior iliac spine (AIIS) to be the foremost prevalent avulsion site representing 33.1% of pelvic avulsion fractures. However, ischial tuberosity (IT) and anterior superior iliac spine avulsions follow closely with 29.6% and 27.8%, respectively (1). Bilateral or sequential avulsion fractures have been shown to occur for the IT and theAIIS (3,5).Moreover, the occurrence of reinjuries is mentioned in an article by Schuett et al. (2). They report that patients with an AIIS avulsion fracture are 4.47 times more likely to have future hip pain and that half of the patients with future hip pain had a distinct reinjury. However, no further elaboration on these cases was presented. No structured report of recurrent AIIS avulsion exists to date. We present a case of recurrent AIIS avulsion following radiographically proven consolidation 1 year after initial trauma.