Comparable Early Functional Recovery Between Robotics-Assisted Superior Transverse Atraumatic Reconstruction (STAR) Total Hip Arthroplasty and the Direct Anterior Approach: A Six-Month Propensity-Matched Study

Purpose: There is limited literature on the functional outcomes of robotics-assisted (RA) superior transverse atraumatic reconstruction approach (STAR) in total hip arthroplasty (THA). This study compares the early functional outcomes, patient satisfaction, expectation fulfilment and complication rates between STAR RA-THA and direct anterior approach (DAA) RA-THA. Methods: We retrospectively analyzed all primary RA-THA performed between January 2022 and December 2024 at a high-volume tertiary centre. Patients undergoing either the DAA or STAR THA with available 6-month outcomes were included. There was a total of 123 patients (74 DAA and 49 STAR). Propensity score matching was used to account for baseline differences, generating 49 matched pairs based on age, sex, body mass index (BMI), and American Society of Anesthesiologists (ASA) grade. Postoperative patient-reported outcome measures (PROMs) and the proportion achieving minimum clinically important difference (MCID) were compared between groups. PROMs included were the Oxford Hip Score (OHS), Western Ontario and McMaster University Arthritic Index (WOMAC), Short-Form 36 Health Survey (SF-36) subscale, patient satisfaction score and expectation fulfilment score. Results: The DAA group demonstrated significantly better postoperative day one (POD1) ambulation distance (p = 0.00390). No differences in PROMs, MCID, patient satisfaction and expectation fulfilment scores were noted at last follow-up. The RA-DAA group had a higher incidence of meralgia paresthetica (p = 0.00260). Conclusions: The STAR RA-THA demonstrated early functional recovery comparable to DAA RA-THA. Although POD1 ambulation distance was greater in the DAA group, at six months, both approaches had similar functional outcomes, patient satisfaction and low complication rates.