A Simple Device to Determine Ante-Version During Femoral Prosthesis Insertion in Total Hip Replacement

Abstract

Introduction: Good outcomes in Total Hip Replacement (THR) depend upon correct component alignment. This is influenced by the surgeon’s capacity to recreate a geometrically normal and biomechanically stable hip joint. Mal-positioining of components can lead to various complications and the surgeons have to make vital decisions intra-operatively based on their experience. Materials and Methods: This study describes a simple instrument to aid alignment of femoral stem insertion and hence achieve the normal range of ante-version between 10 º-20 º. Experiments performed on a saw bone model by twenty orthopaedic surgeons, each making six attempts to insert a prosthesis demonstrated improved positioning when compared to unaided insertion. Results: The mean average femoral stem ante-version unaided was 18.3 º (range, 4.9 º to 36.6 º). Device aided ante-version was 14.4 º (range, 9.8 º to 18.9 º) (p<0.001). We also report the practicality of the use of the device which was assessed by use on cadavers. Conclusion: Precise assessment of stem ante-version can be achieved in non-navigated THR if such a device is available intra-operatively.