Medial migration of lag screw with intrapelvic dislocation in gamma nailing--a unique problem? A report of 2 cases.

Within the last decade, intramedullary nailing systems have gained popularity in the treatment of unstable fractures of the trochanteric region with good clinical results. However, these implants are not free of complications. Commonly reported treatment failures include implant cutout through the femoral neck, stress-derived femur fractures at the distal end of the nail, and secondary rotational displacement and varus deformity of the femoral neck and head. Only few reports exist on primary medial migration of the lag screw after treatment with intramedullary implants. We report on a rarely described complication in 2 patients who underwent osteosynthesis with a Gamma 3 nail (Stryker, Mahwah, NJ). Both patients presented with implant failures due to primary medial migration of the lag screw. Complete separation of the implant occurred, and the lag screw penetrated through the acetabulum into the pelvis. The patient's histories and course of treatment are reported. The literature on this topic is discussed.