Rare intrapelvic migration of a sliding hip screw after hip fracture fixation.

Sliding hip screws (SHSs) are commonly used for the operative treatment of extracapsular neck of femur fractures. We report 2 rare cases of intrapelvic migration of an SHS, resultant of non-unions, threatening regional major vessels. Only a handful of such cases have previously been reported in the literature. We provide an up-to-date review of the literature, propose rationale for how a lag screw may migrate, and suggest how this complication can be prevented.