抄録
Objective: Previously, total hip arthroplasty (THA) for elderly patients suffering from osteoporosis and patients with rheumatoid arthritis (RA) has been done using cement to provide ridged primary fixation. Recently, however, the implants for cementless THA have advanced remarkably. Several authors have reported satisfactory results for cementless THA carried out in elderly patients and patients with RA whose bone qualities were considered to be poor. In this study, we attempt to demonstrate, using short-term results, the efficacy and safety of cementless THA carried out with the S-ROM system in elderly patients older than 70 years of age.
Methods: Between January 2006 and December 2007, 184 cementless THAs were performed using the S-ROM system at our institution. Cases in which simultaneous bilateral THA and revision THA were performed were excluded from this study, leaving 134 THAs in 134 patients. Among these 134 patients, 44 were older than 70 years of age, and 26 were followed up for a minimum of 24 months. The average age of these 26 patients (4 men and 22 women) at the time of surgery was 75.4 years. Initial diagnosis was osteoarthritis in 25 hips and rheumatoid arthritis in 1 hip, and the mean follow-up period was 31.2 months. We evaluated the clinical results (in terms of JOA score) and the radiographical findings.
Results: The mean JOA score was 41.7 preoperatively and 91.8 at the final follow-up. In all 26 patients, the S-ROM stem was biologically fixed by bone ingrowth fixation regardless of the canal flair index. In seven patients, femoral component subsidence of more than 2 mm was found, but there were no differences in clinical outcomes. In three patients, femoral fracture at the site of implantation occurred when press fitting, necessitating rigid fastening at the fracture site by circumferential wiring with nonabsorbable suture. Thus, postoperative treatment could be managed by a clinical approach in the same way as for the other patients.
Conclusion: In this study, we demonstrated satisfactory short-term results of cementless THA using the S-ROM system for patients whose bone quality was considered to be poor.
