Comparative Analysis of Implant Effectiveness in Maintaining the Stability of the Reverse Obliquity Hip Fracture

The reverse obliquity hip fracture is an unstable intertrochanteric fracture. The existing treatments of the reverse obliquity hip fracture have a high failure rate leading to re-operation. The objective of this study was to design an experimental setup to systematically evaluate and quantitatively document the effectiveness of various fixation devices used to treat the reverse obliquity hip fracture. The fixation devices tested and analyzed were 1) the 135 Degree Dynamic Hip Screw with a Trochanteric Stabilizing Plate (DHS/TSP)®, 2) the 95 Degree Condylar Hip Screw (CHS)®, and 3) the Recon Nail®. These devices were implanted in composite sawbone specimens with material properties close to that of human bone. All devices were tested under identical cyclic loading conditions. Based on a quantitative stability analysis, the 95 Degree CHS® showed the most promise for treatment of non-comminuted reverse obliquity hip fractures. The Recon nail® caused the bone to fracture at areas of high stress concentration and the 135 Degree DHS/TSP® was associated with high values of stress shielding. In this paper, the experimental set-up will be presented, the generated data will be discussed, and the performance of each fixation device will be analyzed.