Results of the femur fractures treated with the new selfdynamisable internal fixator (SIF)

PURPOSE: As axial dynamisation is a recognised method, many authors using interlocking femoral nail perform an additional small operation two months after the primary operation in order to remove one screw so as to provide axial dynamisation. According to the literature, dynamisation happens in about 15–25% of cases, but it cannot be predicted which patient or fracture will need dynamisation. The aim of this study is to present a new selfdynamisable implant and a minimally invasive method for the internal fixation of different femoral fractures. MATERIALS AND METHODS: The study was conducted between 2000 and 2008 and included 849 patients with 871 fractures receiving the selfdynamisable internal fixator (SIF) for proximal, diaphyseal and distal femur fractures. RESULTS: The average operative time was 44 min (23–119 min) and the average fluoroscopy time was 12 s (6–92 s), while the average blood loss was 90 ml (60–250 ml) when a minimally invasive technique was used. None of the patients developed complications during the intra-operative period. Complete follow-up was available in 726 patients with 738 fractures. The healing time was 3.9 months (3–9 months). Healing was achieved in 99.1% of patients. Superficial infection developed in seven fixations (0.9%), while deep infection developed in four patients (0.5%). Screw-breaking occurred within 6–18 weeks in 19 fixations (2.6%). Cut-out phenomenon happened in 24 cases. Spontaneous axial dynamisation was observed in 71 (23.8%) out of 738 fractures, being 5 mm on average (2–12 mm). CONCLUSION: The SIF is an effective method for the treatment of femoral fractures. This method is particularly valuable in the treatment of comminuted fractures with regard to minimally invasive surgery. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00068-011-0157-7) contains supplementary material, which is available to authorized users.