Is There Still a Place for Threaded Spherical Acetabular Components in Modern Arthroplasty? Observations Based on an Average 14-Year Follow-Up

TL;DR

This study shows that threaded spherical acetabular components in hip replacement surgery provide good long-term results, especially for complex cases like dysplastic hips.

Contribution

The study provides long-term clinical and radiographic outcomes of cementless THA using spherical screw-in acetabular components over an average of 14 years.

Findings

58.7% of hips achieved excellent MAP scores at final follow-up.

VAS pain scores improved significantly from 7.1 to 1.8.

Implant survival rates were 98.3% at five years and 94.0% at ten years.

Abstract

Background: Total hip arthroplasty (THA) remains the standard treatment for advanced osteoarthritis, including for complex deformities. Innovations such as spherical screw-in acetabular components aim to enhance fixation and long-term outcomes. This study evaluated the long-term clinical and radiographic outcomes of cementless THA using such implants. Methods: A retrospective analysis was conducted on 277 patients (293 hips) who underwent THA with a screw-in acetabular cup (Aesculap/BBraun SC, Tuttlingen, Germany) and Antega femoral stem between 2005 and 2024. Patients were evaluated using the modified Merle d’Aubigné and Postel (MAP) score, Visual Analog Scale (VAS), and radiographic classifications, with implant survival assessed via Kaplan–Meier analysis. Results: The mean follow-up was 13.8 years. At the final follow-up, 58.7% of hips achieved excellent MAP scores, and mean VAS pain scores improved from 7.1 to 1.8 (p < 0.05). Implant positioning was within the Lewinnek safe zone in 77.1% of cases. Revision was required in 6.1% of hips, mostly due to aseptic loosening. The five- and ten-year survival rates were 98.3% and 94.0%, respectively. Conclusions: Spherical screw-in acetabular cups provide durable fixation and satisfactory long-term outcomes in THA, particularly for dysplastic hips, supporting their continued use with careful surgical techniques.

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