Additional Fixations for Sliding Hip Screws in Treating Unstable Pertrochanteric Femoral Fractures (AO Type 31-A2): Short-Term Clinical Results

BACKGROUND: To evaluate the utility of additional fixation methods and to suggest a method of reduction in the treatment of unstable pertrochanteric femur fractures with a sliding hip screw (SHS). METHODS: A retrospective study was performed on thirty patients with unstable pertrochanteric femur fractures, who were operated on with a SHS between September 2004 and September 2009 and were followed up for at least 6 months. The additional fixation devices were as follows; antirotation screw (21 cases), fixation of displaced fractures of the posteromedial bone fragment (cerclage wiring, 21 cases and screw, 2 cases) and trochanter stabilizing plate (27 cases). Clinically, the Palmer's mobility score and Jensen's social function group were used. Radiologically, alignment and displacement were observed. The tip-apex distance (TAD) and sliding of the lag screw were measured, and the position of the lag screw within the femoral head was also examined. RESULTS: The mean age at the time of surgery was 76 years (range, 56 to 89 years) and the average follow-up period was 25 months (range, 6 to 48 months). At the last follow-up, the average mobility and social function score was 6.2 (± 3.5) and 2.3 (± 1.5). Postoperatively, the alignment and displacement indices were adequate in almost all the cases. The mean amount of lag screw sliding and the mean TAD was 5.1 mm (range, 2 to 16 mm) and 6 mm (range, 3 to 11 mm) respectively. The lag screws were located in the center-center zone in 21 cases. The average period to union was 18.7 weeks without any cases of nonunion or malunion. Mechanical failure was noted in one case with breakage of the lag screw and clinical failure was noted in another case with persistent hip pain related to excessive sliding (16 mm). CONCLUSIONS: With additional fixations, the unstable pertrochanteric femur fractures could be well stabilized by SHS until bone union.