Acetabular Migration of Lag Screw of Intramedullary Nail Used as Treatment for Intertrochanteric Fracture. Case Study

Most trochanteric fractures of the femur are classified as low-energy fractures as they are seen in people with decreased mechanical properties of bone tissue. The treatment is assumed to provide biomechanical fixation with the possibility of dynamization between bony fragments to stimulate the biological processes of bone union. The aim of the study was to analyze a complication presenting as migration of the cervical screw of an intra-medullary nail towards the hip joint acetabulum and present the therapeutic management of this complication. The case report concerned a 74-year-old patient with an AO/OTA type 31 A2.2 fracture of the trochanteric massif of the right femur treated with the Gamma3 intramedullary nail. An assessment of changes over time of the radiological appearances on A-P images after the surgery showed migration of the cervical screw towards the acetabulum and displacement of the major trochanter fracture. Extensive destruction of the acetabular fossa made biologic restorative treatment impossible. A total hip joint prosthesis with a modular stem and MDM articulation was implan-ted and the trochanter was fixed with a "hook" plate with a "cable system". The postoperative course was uneventful. Failure to perform axial radiographs in the preoperative and postoperative period made it impossible to objectively determine the type of fracture and the quality of screw insertion into the femoral neck, and assessment limited to A-P images turned out to be deceptive. The wandering of the screw towards the acetabulum led to extensive destruction of the acetabular fossa. The decision to stop biological treatment, which, if properly performed, stimulates bone union, and perform the mechanical procedure of endoprosthesoplasty was fully prognostically justified. The early and late postoperative course was not complicated.