Fractures of the thigh bone (femur) just below the hip joint capsule (extracapsular hip fractures) may be surgically fixed using a variety of implants. One particular type of implant is the sliding hip screw, which consists of a screw that is inserted into the upper part of the (femur) to bridge (fix) the fracture. This screw can move within a metal barrel connected to a plate that is screwed to the outside of the femur. Implants of this sort of design are called 'extramedullary'. Intramedullary implants are nails inserted from the top of the femur into the inner cavity of the femur bone ('the medulla') and held in place with screws. This review compared these two types of implants in predominantly older populations.
The main results were for the comparisons of various types of intramedullary nails with the sliding hip screw. Twenty-two trials, involving 3749 participants, tested the Gamma nail. Five trials, involving 623 participants, tested the intramedullary hip screw (IMHS). Three trials, involving 394 participants, tested the proximal femoral nail. Other trials involved newer varieties of intramedullary nails. Most older trials showed a tendency for the nails to be associated with an increased risk of fracture of the thigh bone both during and after the operation. More recent trials testing newer varieties of nails seemed to avoid this specific problem to some extent. The review found that using intramedullary nails resulted in one extra reoperation in every 50 people. Mortality and, where data were available, other long-term outcomes were similar between the implants.
The review concluded that current evidence supports the continued use of the sliding hip screw for fixing the more common types of extracapsular hip fractures. This may not be the case for some of the more recently developed designs of intramedullary nails or for specific fracture types, but further research is required to confirm this.