The accuracy of navigated imageless total hip arthroplasty compared to conventional total hip arthroplasty in respect of leg length and hip off-set restoration

Abstract

Abstract Background While previous studies on navigated total hip replacement (nTHA) focused on acetabular component positioning, we compared the results of nTHA with conventional total hip replacement (cTHA) in respect to leg length and hip offset restoration. Methods In a single-center study results radiographic parameters of patients with unilateral THA were included. Data were prospectively collected and then retrospectively analyzed from computer navigation data and radiographs. Analysis concentrated on the discrepancy in leg length (LLD) and hip offset (OSD) between the affected and unaffected hip. The restoration effect was defined as the difference between postoperative and preoperative LLD and OSD values in each group. Results 2332 patients were analyzed. Both nTHA and cTHA were effective in restoring LLD and OSD by reducing the preoperative value significantly (p < 0.001). Regarding LLD restoration, no statistical difference between nTHA and cTHA could be found.OSD restoration nTHA was a slightly more effective than cTHA (-2.06 + 6.00 mm vs.-1.50 + 5.35 mm; p < 0.05). Conclusion Both navigated and conventional THA were successful in restoration of leg length and hip offset, while postoperative offset discrepancy was significantly lower in the navigated group at the cost of longer operation times. If these results are clinically relevant further investigation is needed. Level of evidence: III: retrospective case series study, therapeutic investigation of a treatment.