Evaluation of Navigation-Assisted vs. Conventional Total Hip Arthroplasty → Δ Implant Position Accuracy (± Limb Length Discrepancy) and Functional Outcomes

Abstract

Background: Total hip arthroplasty (THA) is widely performed; however, malposition, limb length discrepancy (LLD), and suboptimal outcomes remain prevalent, prompting comparisons between navigation-assisted and conventional techniques. Objective: This study evaluates navigation-assisted versus conventional THA in terms of implant positioning accuracy, limb length discrepancy, and functional outcomes, assessing radiographic precision, clinical recovery, and patient-reported scores to determine superiority. Methods: A prospective comparative study was conducted in the Department of Orthopedic Surgery, Anwer Khan Modern Medical College, Dhaka, Bangladesh. A total of 106 patients undergoing primary unilateral THA from January– June 2023 was randomized to navigation-assisted (n=53) and conventional (n=53) groups. Radiographic parameters (cup inclination/anteversion, stem alignment, LLD), functional scores (HHS, WOMAC), operative time, complications, and revision rates were analyzed. Results: Navigation-assisted THA demonstrated significantly reduced mean cup inclination deviation (2.3° ±1.2) compared with conventional (5.6° ±2.1; p<0.001). Anteversion accuracy was higher in navigation (3.1° ±1.5 vs. 6.8° ±2.4; p<0.001). Mean postoperative LLD was 2.6 mm ±1.4 in navigation versus 6.9 mm ±3.1 in conventional (relative reduction 62%; p<0.001). Functional outcomes improved, with HHS at 6 months averaging 92.4 ±4.6 in navigation versus 85.7 ±5.8 in conventional (p=0.002). WOMAC scores indicated lower pain/stiffness scores in navigation (12.8 ±3.2 vs. 18.4 ±4.5; p=0.004). Complication rates were lower in navigation (7.5% vs. 17%; relative risk reduction 55%). No early revision occurred in navigation, while two revisions (3.7%) occurred in conventional. Conclusion: Navigation-assisted THA significantly enhances implant positioning accuracy, minimizes LLD, and improves short-term functional recovery compared with conventional methods, suggesting superiority in precision and early outcomes within resource-limited healthcare settings.