10-year results after primary total hip arthroplasty for severe dysplastic hip osteoarthritis with far proximal cup position.

INTRODUCTION

This study presents clinical und functional long-term outcomes up to 10 years after primary total hip arthroplasty (THA) without concomitant surgical intervention and a far proximal cup positioning.

METHODS

33 patients (44 hips) underwent primary THA for severe dysplastic hip osteoarthritis with a far proximal cup position. Hips were divided into two groups: Group A (n = 27) with cups positioned at 55-65 mm and Group B (n = 17) with cups positioned > 65 mm from the interteardrop line. Functional outcomes were assessed at 114 ± 15 months postoperatively using LEFS, HHS, HOOS, and Tegner Activity Score. Patient satisfaction and leg length difference were also evaluated. Statistical analysis employed the Mann-Whitney U test (p < 0.05 significance level).

RESULTS

The study found no significant differences in the two groups in terms of functional results, as measured by HOOS (89.1 ± 12.1 vs. 89.0 ± 8.3; p = 0.5145), LEFS (66.7 ± 13.1 vs. 68.7 ± 11.5; p = 0.5544), and HHS (95.1 ± 7.4 vs. 94.9 ± 4.4; p = 0.2707). Both groups showed very good functional results. The Tegner Activity Score significantly improved in both groups from preoperative to final follow-up (A: 2.1 ± 1.4 to 4.0 ± 0.7; p = 0.0002; B: 1.8 ± 1.1 to 3.9 ± 1.1; p = 0.0009). There were no significant differences found when comparing the pre- and postoperative leg length differences (p = 0.5793). No complications including dislocation events, impingement or neurological complications were observed. Furthermore, no patient required revision surgery.

CONCLUSION

Primary total hip arthroplasty with far proximal, non-anatomic socket positions is a safe and effective treatment option with excellent functional long-term results in severe dysplastic hip osteoarthritis.