LEG LENGTH DISCREPANCY FOLLOWING TOTAL HIP ARTHROPLASTY – CAN WE AVOID IT?

Abstract

Introduction: Leg length discrepancy (LLD) following total hip arthroplasty (THA) can lead to disappointed patients, increased dislocation, increased wear and suboptimal function. It is one of the commonest reasons for litigation following THA in the United States. The purpose of this study was to radiologically and functionally assess the efficacy of a simple technique for intra-operative leg length assessment during THA via a posterior approach.

Materials & Methods: This technique was undertaken in 50 consecutive THAs. The pre-and 3 month postoperative LLD was measured on standing AP pelvis radiographs. The results were compared with 50 THAs performed by the same surgeons without using the technique. Pre-and post-operative OHS and UCLA scores were recorded in both groups.

Results: In the control group the mean pre- and postoperative LLD was 9.38 mm and 7.75mm respectively. In the new technique group the mean pre-operative LLD was 11.37 and the post-operative LLD was 1.70mm. The final LLD was significantly less in the new technique group (p< 0.001). Fifteen patients in the control group and three patients in the new technique group had post–operative lengthening. Oxford Hip and UCLA score improvement in new technique group was greater than in the control group (p< 0.05).

Discussion: The technique we introduced to assess leg length intra-operatively has shown to be safe, reliable and accurate. We have nonetheless demonstrated much greater accuracy at providing equal leg lengths and improved functional outcome using this new technique.