Medium-term outcomes of uncemented total hip arthroplasty in patients younger than 25 years old: A retrospective research

Abstract

Abstract Objective: To evaluate the medium-term outcomes of uncemented total hip arthroplasty in patients ≤ 25 years. Methods: A retrospective research was performed on patients ≤ 25 who received uncemented total hip arthroplasty at the Department of Orthopedics of the 940th Hospital of Joint Logistic Support Force of Chinese People’s Liberation Army from January 2009 to December 2018. The clinical evaluation was measured with modified Harris Hip Score, Western Ontario & McMaster Universities Osteoarthritis Index, and Short-Form 36. Postoperative complications (such as infection, revision, dislocation, and incisional healing issues) were recorded. Using pelvic anteroposterior, hip anteroposterior and lateral X-rays, the radiographic outcome was evaluated, including the position of the implants, loosening, bearing-surface wear, osteolysis, and heterotopic ossification. Loosening of the acetabular or femoral component or revision for any reason was defined as failure. Results: At a follow-up of 8.3±2.4 years (range, 3.8 to 12 years), the preoperative modified Harris hip score was 43.5±12.9 (range, 18 to 62) and increased to 88.3 ± 8.8 (range, 72 to 97), and the preoperative postoperative Western Ontario & McMaster Universities Osteoarthritis Index score improved from 43.6±8.4 (range, 33.1 to 62.3) to 11.5 ± 6.8 (range, 2.5 to 25.8). The Physical Component score-SF-36 improved from 48.5 ± 8.6 (range, 36.4 to 61.3) to 81.2 ± 10.3 (range, 60.3 to 97.5), while the Mental Component score-SF-36 increased from 56.6±12.5 (range, 39.4 to 78.6) to 82.6 ± 12.9 (range, 54.7 to 97). The latest X-ray revealed that the position of the implants did not change substantially since the postoperative image. The abduction angle of acetabular cup was 41.8° ± 6.7° (range, 31° to 57°),the anteversion angle of acetabular cup was 18.2° ± 3.6° (range, 9.5° to 25.7°), and the filling ratio was 90.1% ± 3% (range, 85.2%-95.3%). The preoperative leg length discrepancy was 1.8 cm ± 0.8 cm (range, 1 cm to 5 cm) and reduced to 1.4 cm ± 0.5 cm (range, 0.5 cm to 2.5 cm). No considerable loosening, bearing-surface wear, osteolysis, or heterotopic ossification was observed. At the latest follow-up, the overall survival rate of the 49 hips was 98%. Conclusion: For patients with end-stage hip disease under 25 years old, uncemented THA exhibit excellent outcomes, with a high survival rate and fewer complications at medium-term follow-up.