Introduction: Successful treatment of hip fractures during the first operative episode is paramount in minimizing patient morbidity and socio-economic costs. Peri-trochanteric hip fractures are a subtype of unstable intertrochanteric hip fractures which experience an increased rate of fixation failure. Although current literature suggests that successful surgical treatment of peri-trochanteric fractures is dependent on fracture pattern, quality of fracture reduction, implant choice and implant position, there is no agreement either to the relative importance of each or their inter-relationship. Consequently, the overall aim of this thesis was to assess the predictors of fixation failure and their relationship to each other in the treatment of peri-trochanteric fractures. Methods: A retrospective review of 796 patients with peri-trochanteric fractures treated at a tertiary referral trauma centre between 2008 and 2012 was undertaken. Analysis of pre-operative, intra-operative and post-operative radiographs was performed using Centricity PACS. Analysis of potential confounding factors included age, gender, fracture classification, reduction quality, Cleveland zone, tip-apex distance, implant type (DHS versus short Gamma nail versus long Gamma nail), and fixation points in Gamma nails, specifically the lateral cortex, greater trochanter, and fit of the nail in the intramedullary canal at its narrowest point. Results: Unstable fractures had a 7.6 (OR 3.0-19.6) times increased risk of fixation failure (p 20 mm incurred a 2.2 (OR 1.7-2.73) increased risk of failure (p<0.001), it was not powerful enough to mitigate against fixation failure in the event of poor fracture reduction (p<0.004). Nail fit was noted to be a predictor of fixation failure, with a 10.3 (OR 8.1-28.4) times increased risk of failure if the nail filled < 70% of the intramedullary canal (p<0.001). There was no significant difference in choice of implant or increased rate of failure when using a DHS or Gamma nail except in reverse oblique type factures. Fixation points of the lateral cortex and greater trochanter were not associated with successful osteosynthesis. Discussion: Unstable fracture type, poor fracture reduction, non optimal cephalomedullary screw positioning, and inadequate fit of IM recon nails in the intramedullary canal were predictors of fixation failure. These factors are closely interrelated: unstable fractures may be difficult to reduce which in turn leads to difficulty in achieving correct positioning of implants. A poorly reduced fracture will not be mitigated from fixation failure by correct positing of implants. Treatment of peri-trochanteric fractures should therefore be aimed at obtaining a high quality of fracture reduction prior to ensuring optimal lag screw position and intramedullary nail fit to maximize the success rate of osteosynthesis
