“The Wayward Screw”: A Rare Case Report of Intrapelvic Migration of a Cephalomedullary Lag Screw

Introduction: Intrapelvic migration of cephalomedullary screws is an exceptionally rare but potentially life-threatening complication of internal fixation of intertrochanteric femur fractures. When displaced implants lie near major vascular structures, the clinical concerns rise significantly. This case highlights the importance of early recognition, detailed imaging, and multidisciplinary surgical coordination in managing this high-risk scenario. Case Report: An 85-year-old male underwent short cephalomedullary nail fixation for a left intertrochanteric femur fracture. After a subsequent fall in a respite facility, investigations revealed superomedial migration of the lag screw into the pelvic cavity. Computed tomography angiography showed the screw tip lying within 2  cm of the iliac bifurcation, without evidence of hemorrhage or visceral injury. A multidisciplinary team, including orthopedic, vascular, and general surgeons, recommended operative retrieval. An initial exploratory laparotomy was aborted due to intraoperative bleeding risk. Definitive removal was achieved safely via a second laparotomy 2 weeks later, with an uneventful post-operative course. Discussion: This case highlights a rare but dangerous complication. Unlike more routine cases of implant failure managed through direct hip revision alone, the intrapelvic trajectory and vascular proximity in this case required intra-abdominal retrieval. High-resolution imaging was critical in defining anatomy and risk, and the collaborative surgical approach ensured a successful outcome. Conclusion: Superomedial migration of cephalomedullary screws can pose an imminent danger due to their proximity to critical pelvic structures. When standard revision techniques are not feasible, multidisciplinary surgical planning, guided by advanced imaging, becomes essential to avoid catastrophic outcomes. Keywords: Intertrochanteric fracture, intrapelvic screw migration, cephalomedullary nail, laparotomy, orthopedic implant complication, case report.