Highly accurate component placement does not improve patient‐reported outcomes after total hip arthroplasty: A computerised tomography‐based study

Purpose To compare total hip arthroplasty (THA) outcomes between those with and without highly accurate component placement relative to the preoperative plan on computerised tomography (CT) criteria. Methods Primary THA patients with preoperative and postoperative CT scans who completed baseline and 1‐year patient‐reported outcomes (PROMs) were included. Patients were allocated to the ‘precise anatomic restoration (PAR)’ group if they met all criteria for component position relative to the preoperative plan: within 5 mm of femoral offset and leg length and within 10 degrees of combined anteversion and inclination of the acetabular cup. Those who did not meet these criteria were allocated to the control group. Outcomes were compared between groups for 1‐year PROMs, including the Oxford hip score (OHS), hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement Score (HOOS JR) and satisfaction. Results Of 125 participants, 70 (56%) were allocated to PAR while 55 (44%) to control. There was no significant difference between groups for 12‐month OHS ( p = 0.438), HOOS JR ( p = 0.630), the proportion achieving PASS for OHS ( p = 0.495), HOOS JR ( p = 0.575) or satisfaction ( p = 0.854). There was no significant correlation between component position error on CT and 12‐month PROMs. Conclusion Highly accurate THA component placement does not translate to superior PROMS, compared to those with small errors in component placement at 1 year after THA. The implications for hip arthroplasty practice are substantial: achieving high levels of technical accuracy through advanced technologies may not consistently translate into measurable improvements in patient outcomes. Level of Evidence Level II.