Total Hip Arthroplasty Using the S-ROM-A Prosthesis for Anatomically Difficult Asian Patients

Abstract EN

Background.

The S-ROM-A prosthesis has been designed for the Asian proximal femur with a small deformed shape and narrow canal.

In this study, the clinical and radiological results using the S-ROM-A prosthesis for Japanese patients with severe deformity due to dysplasia and excessive posterior pelvic tilt were examined.

Methods.

94 hips were followed up for a mean of 55 months, with a mean age at surgery of 61 years.

The primary diagnoses were 94 coxarthritis cases, including 51 dysplasia and 37 primary OA, 1 avascular necrosis, 2 traumatic arthritis, and 3 Perthes disease.

Thirty-one hips had been treated with osteotomy of the hip joints.

Preoperative intramedullary canal shapes were stovepipe in 23 hips, normal in 51 hips, and champagne-flute in 5 hips.

The maximum pelvic inclination angle was 56°.

Results.

The mean JOA score improved from 46 points preoperatively to 80 points at final follow-up.

On radiological evaluation of the fixation of the implants according to the Engh classification, 92 (97%) hips were classified as “bone ingrown fixation.” Conclusion.

In primary THA, using the S-ROM-A prosthesis for Asian patients with proximal femoral deformity, even after osteotomy and with posterior pelvic tilt, provided good short- to midterm results.