Aims The latest generation of CT guided robotic-arm assistance in THA incorporates pose-aware planning and intraoperative virtual range of motion (vROM) simulation, enabling dynamic, functional component positioning based on each patient's spinopelvic profile. This study aimed to determine whether these new features provide additional advantages over the previous robotic platform and conventional CT-planned THA in terms of accuracy and early patient-reported outcomes. Methods This prospective cohort emulated the protocol of our previously published randomized controlled trial comparing conventional THA with an earlier generation of the robotic-arm assisted THA platform. Forty-five consecutive patients underwent primary THA using the latest robotic software (4.0 platform) between 2023 and 2024, adhering to identical eligibility criteria, imaging and follow-up schedules. Outcomes were compared with 30 conventional and 30 earlier-generation robotic cases (3.0 platform) from the prior trial. The primary endpoint was the Forgotten Joint Score (FJS-12) at one year, powered to detect the minimal clinically important difference (8 points; SD 14; α = 0.05, β = 0.20). Secondary endpoints included component positioning, accuracy of restoring the centre of rotation (COR), combined offset, leg length, and outlier rates. Inverse probability of treatment weighting was applied to adjust for covariate imbalance. Results Mean absolute errors in horizontal and vertical COR were 1.3 mm and 0.9 mm, respectively- comparable to 3.0 platform and significantly more accurate than conventional THA (p 5 mm deviation of the COR) were lower with the 4.0 software (11%) than 3.0 (17%) and conventional (43%) (p = 0.003). The mean FJS-12 was 88.2 ± 7.6 for 4.0 platform, versus 85 ± 8.8 for 3.0 and 83 ± 9.6 for conventional (one-way ANOVA, p = 0.009). Other PROMs (OHS, WOMAC, HOOS) and quality of life was comparable across groups. Conclusion Functionally enabled robotic-arm assisted THA achieved comparable precision to earlier robotic softwares and a clinically meaningful improvement in FJS-12 compared with conventional techniques. These findings suggest that shifting from geometric to functional planning may offer incremental benefits; long-term studies are warranted to determine whether these benefits translate into sustained clinical and implant-survival gains.
Fares S Haddad (Thu,) studied this question.