Novel method for ensuring leg length in total hip arthroplasty

Despite the overwhelming clinical success of total hip arthroplasty, complications such as leg-length discrepancy can be a significant cause of functional impairment and patient dissatisfaction. Multiple intraoperative techniques are available for measuring femoral limb length; however, many require additional invasive hardware and those that do not are less accurate at measuring limb length. This article introduces a novel, noninvasive intraoperative technique that quickly and accurately measures limb length and prevents postoperative leg-length discrepancy.The authors' method relies on the accurate reproduction of a line perpendicular to the femoral axis near the proximal aspect of the greater trochanter intraoperatively and during preoperative planning and requires minor modifications to the instrumentation used. A narrow slot for the placement of a guide plate was machined into a standard trial head 37° from the axis of the neck for use with a high offset 127° Secur-Fit PLUS stem and 42° from the axis of the neck for use with a standard offset 132° Secur-Fit stem (Stryker Orthopaedics, Kalamazoo, Michigan). Once a broach is securely seated, a trial neck, slotted trial head, and guide plate are assembled and the distance from the guide plate to the proximal tip of the greater trochanter is compared with the preoperative planning measurements to assess the stem position.A retrospective radiographic analysis of 31 consecutive primary total hip arthroplasty using this technique showed the mean postoperative leg-length discrepancy to be 2.18±6.08 mm. This method is an additional tool for the arthroplasty surgeon's armamentarium to ensure accurate leg-length restoration.