Long-term results of short stem total hip arthroplasty in patients with osteonecrosis of the femoral head.

INTRODUCTION

Short stem total hip arthroplasty (THA) is an alternative to conventional stem, designed to facilitate minimal-invasive surgery, physiological loading and preserve bone stock. However, there is insufficient evidence of the long-term outcomes in patients with osteonecrosis of the femoral head (ONFH). This study aims to analyze the clinical and radiographic results with a minimum follow-up of 10 years. Furthermore, the survival rate of the short stem was calculated.

MATERIALS AND METHODS

There were 81 patients (101 hips) with the mean age of 45 years (range, 21 to 68) in this study. The Harris Hip Scores (HHS) and Forgotten Joint Scores (FJS) were recorded to evaluate the clinical results. The appearance of osteointegration and radiolucent line were reviewed. The mean follow-up period was 129.3 months (range, 120-154).

RESULTS

At the latest follow-up, the mean HHS and FJS were 96.9 ± 5.7 (range, 69-100) and 95 ± 7 (range, 75-100) points respectively. The radiographic changes around the stem showed osteointegration mainly in the proximal part, zones 1 (94.1%), 2 (84.2%), 6 (99%) and 7 (92.1%). One stem underwent revision due to periprosthetic fracture, using conventional stem with plate and screws. Survivorship of the stem with the endpoint for any reason was 99.01% (95% confidence interval [CI], 93.18-99.86%) and for aseptic loosening was 100% at 10 years.

CONCLUSION

Short stem showed promising long-term clinical outcomes in patients with ONFH. The radiographic results demonstrated physiological proximal load transfer.