Archives of Orthopaedic and Trauma Surgery - 2026-04-17 - Journal Article
Minimum 10-year outcomes of cementless total hip arthroplasty using a 32-mm femoral head with CT-based navigation: a comparative study with manual technique.
Tone S, Naito Y, Kobayashi G, Sudo A, Hasegawa M
Topics
Key Takeaway
CT-based navigation achieved 100% cup placement within Lewinnek's safe zone versus 49% with manual technique, yet 10-year implant survival was equivalent (98.2% vs. 100%) and HHS improvement did not exceed the MCID.
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Summary
This study compared CT-based navigation versus manual technique for cementless THA using 32-mm femoral heads, evaluating cup positioning accuracy and minimum 10-year clinical and survivorship outcomes. Navigation achieved 100% placement within Lewinnek's safe zone versus 49% for manual technique (p<0.001), and produced statistically higher Merle d'Aubigné-Postel (16.8 vs. 16.1) and HHS (90.3 vs. 85.0) scores, though neither difference exceeded the MCID. Ten-year Kaplan-Meier survival was 98.2% (navigation) versus 100% (manual), with no significant difference.
Key Limitation
The small sample size (n=111) provides insufficient statistical power to detect meaningful differences in low-frequency endpoints such as dislocation, revision for instability, or bearing surface wear at 10 years.
Original Abstract
INTRODUCTION
Computed tomography ( CT)-based navigation improves the accuracy of component placement in total hip arthroplasty (THA). To date, evidence of its long-term clinical impact is limited. This study aimed to compare minimum 10-year outcomes of cementless THA performed using CT-based navigation and a manual technique with a 32-mm femoral head.
MATERIALS AND METHODS
This study included a minimum follow-up of 10 years. The CT-based group included 58 hips and the manual group included 53 hips. Postoperative cup orientation was assessed using CT. Clinical outcomes were evaluated using the Merle d’Aubigné and Postel score, Harris Hip Score (HHS), and Forgotten Joint Score-12 (FJS-12). Kaplan–Meier analysis was used to estimate the 10-year implant survival with revision for any reason as the endpoint.
RESULTS
The CT-based group achieved a significantly higher cup placement accuracy (100% within Lewinnek’s safe zone versus 49% in the manual group, p < 0.001). At the final follow-up, the CT-based group showed higher Merle d’Aubigné and Postel total score (16.8 vs. 16.1, p = 0.035) and HHS (90.3 vs. 85.0, p = 0.015), although the difference in HHS did not exceed the minimal clinically important difference. The FJS-12 scores did not differ significantly (71.1 vs. 62.2, p = 0.051). Ten-year survival rates were 98.2% in the CT-based group and 100% in the manual group (n.s.).
CONCLUSIONS
CT-based navigation improved cup placement accuracy and produced modest improvements in some clinical scores; however, long-term implant survival and clinically meaningful benefits were not superior to those of manual THA.