Cementless total hip arthroplasty in patients ≤ 25 years: favorable survivorship and clinical outcomes at medium-term follow-up

Abstract Objective This study evaluated the medium-term clinical and radiographic results of cementless total hip arthroplasty (THA) in patients aged 25 years or younger. Methods This retrospective cohort study included 37 patients (49 hips) who underwent cementless THA between 2009 and 2020. The mean patient age at surgery was 21.8 years, and the mean follow-up duration was 10.2 years (range, 4.8-16.2 years). Clinical outcomes were assessed using patient-reported outcome measures (PROMs), including the modified Harris Hip Score (mHHS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the 36-Item Short-Form Health Survey (SF-36). Radiographic evaluations focused on implant positioning, leg length discrepancy (LLD), signs of loosening, bearing surface wear, periprosthetic osteolysis, and heterotopic ossification. Postoperative complications and revision surgeries were also documented. Results All PROMs demonstrated statistically significant improvements postoperatively. The mHHS increased from 44.6 to 88.6. The WOMAC score decreased from 42.9 to 7.5. The SF-36 Physical Component Score improved from 48.5 to 81.2, and the Mental Component Score increased from 56.6 to 82.6. Radiographically, optimal implant positioning was achieved, with a mean acetabular inclination of 40.1° and anteversion of 14.2°. LLD was significantly reduced from 0.9 cm to 0.2 cm. Complications included two dislocations, two cases of transient neuropraxia (in patients diagnosed with developmental dysplasia of the hip), and one periprosthetic joint infection treated with debridement, antibiotics, and implant retention (DAIR) plus acetabular liner exchange; because the liner was exchanged, this procedure was counted as a revision event. Periprosthetic osteolysis was observed in five hips (10.2%), but no cases of progressive osteolysis, loosening, or detectable wear were detected. The 10-year implant survivorship was 98.0%. All improvements exceeded the minimal clinically important difference (MCID) thresholds reported for these instruments. Conclusion In this cohort of young patients (≤25 years) without prior hip infection, cementless THA provided substantial clinical improvement, favorable radiographic outcomes, and high implant survivorship at medium-term follow-up, with a low revision rate.