Critical factors in cut-out complication after Gamma Nail treatment of proximal femoral fractures.

BACKGROUND: The most common mechanical failure in the internal fixation of trochanteric hip fractures is the cut-out of the sliding screw through the femoral head. Several factors that influence this complication have been suggested, but there is no consensus as to the relative importance of each factor. The purpose of this study was to analyse the cut-out complication with respect to the following variables: patients' age, fracture type, fracture reduction, implant positioning and implant design. METHODS: 3066 consecutive patients were treated for trochanteric fractures with Gamma Nails between 1990 and 2002 at the Centre de Traumatologie et de l'Orthopedie (CTO), Strasbourg, France. Cut-out complications were identified by reviewing all available case notes and radiographs. Subsequently, the data were analysed by a single reviewer (AJB) with focus on the studied factors. RESULTS: Seventy-one cut-out complications were found (2.3%) of the 3066 trochanteric fractures. Cut-out failure associated with avascular head necrosis, pathologic fracture, deep infection or secondary to prior failure of other implants were excluded from the study (14 cases). The remaining 57 cases (1.85%, median age 82.6, 79% females) were believed to have a biomechanical explanation for the cut-out failure. 41 patients had a basicervical or complex fracture type. A majority of cut-outs (43 hips, 75%) had a combination of the critical factors studied; non-anatomical reduction, non-optimal lag screw position and the characteristic fracture pattern found. CONCLUSIONS: The primary cut-out rate of 1.85% was low compared with the literature. A typical cut-out complication in our study is represented by an unstable fracture involving the trochanteric and cervical regions or the combination of both, non-anatomical reduction and non-optimal screw position. Surgeons confronted with proximal femoral fractures should carefully scrutinize preoperative radiographs to assess the primary fracture geometry and fracture classification. To reduce the risk of a cut-out it is important to achieve both anatomical reduction and optimal lag screw position as these are the only two factors that can be controlled by the surgeon.

3066 consecutive Gamma Nails. 12 years experience at a single centre.

BACKGROUND: Fixation of trochanteric hip fractures using the Gamma Nail has been performed since 1988 and is today well established and wide-spread. However, a number of reports have raised serious concerns about the implant's complication rate. The main focus has been the increased risk of a subsequent femoral shaft fracture and some authors have argued against its use despite other obvious advantages, when this implant is employed. Through access to a uniquely large patient data base available, which is available for analysis of trochanteric fractures; we have been able to evaluate the performance of the Gamma Nail over a twelve year period. METHODS: 3066 consecutive patients were treated for trochanteric fractures using Gamma Nails between 1990 and 2002 at the Centre de Traumatologie et de l'Orthopedie (CTO), Strasbourg, France. These patients were retrospectively analysed. Information on epidemiological data, intra- and postoperative complications and patients' outcome was retrieved from patient notes. All available radiographs were assessed by a single reviewer (AJB). RESULTS: The results showed a low complication rate with the use of the Gamma Nail. There were 137 (4.5%) intraoperative fracture-related complications. Moreover 189 (6.2%) complications were detected postoperatively and during follow-up. Cut-out of the lag screw from the femoral head was the most frequent mechanical complication (57 patients, 1.85%), whereas a postoperative femoral shaft fracture occurred in 19 patients (0.6%). Other complications, such as infection, delayed healing/non-union, avascular femoral head necrosis and distal locking problems occurred in 113 patients (3.7%). CONCLUSIONS: The use of the Gamma Nail in trochanteric hip fractures is a safe method with a low complication rate. In particular, a low rate of femoral shaft fractures was reported. The low complication rate reported in this series can probably be explained by strict adherence to a proper surgical technique.