Abstract: Objective To compare the difference of mid-term outcomes of femoral head prostheses with different diameter for total hip arthroplasty. Methods Retrospective analysis of 42 patients who underwent total hip arthroplasty for end-stage hip disease from March 2010 to September 2013 was conducted. Among them, 21 cases adopted 36 mm large-diameter ceramic femoral head prosthesis(large diameter group), and 21 cases adopted 32 mm small-diameter ceramic femoral head prosthesis(small diameter group). All the patients were followed up for more than 5 years, and differences in efficacy were assessed by Harris hip score and X-ray. Results The mean postoperative follow-up time was(69.71±4.03) months.Up to the last follow-up, the Harris hip score of all patients was significantly higher than that before surgery(84.48±9.06 vs 40.21±9.05, P<0.001), and the Harris hip score of the large diameter group was significantly higher than that of the small diameter group(89.38±9.36 vs 79.57±5.51, P<0.001). The final follow-up X-ray showed that the prosthesis position of all patients was good, and no dislocation of prosthesis was observed in both groups. Conclusion The mid-term outcome of the large-diameter femoral head prosthesis is satisfactory, and the postoperative joint mobility was improved better than that of the small-diameter prosthesis.

Key words: Diameter, Femoral head prosthesis, Total hip arthroplasty