THIRD-GENERATION CERAMIC-ON-CERAMIC BEARINGS IN REVISION TOTAL HIP ARTHROPLASTY

Abstract

Total Hip Arthroplasty (THA) has been more frequently performed for relatively young patients with osteonecrosis of the femoral head in Korea. Moreover, squatting and sitting with crossed legs are more common in Asian cultures than in Western cultures. Wear debris generated by conventional metal-on-PE articulations has been giving rise to extensive osteolysis. Due to these characteristics, higher incidence of pelvic osteolysis was observed after THA in Korea. As a result, interest in alternative bearings such as ceramic-on-ceramic bearing has been increased. Furthermore, the patients who require revision THA are still young in Korea. With this point of view, an application of ceramic-on-ceramic bearing throughout revision THA seems to be reasonable. The clinical and radiographical outcomes after revision THA with use of third generation ceramic-on-ceramic bearing in Korean patients were evaluated.

Materials and Methods: We have analyzed 42 hips (37 patients; 17 men and 20 women), in whom revision THAs were performed using cementless cups with ceramic-on-ceramic bearing (Biolox Forte; CeramTec, Plochingen, Germany). They underwent THA at a single institution between February 2000 and December 2004, and were consecutively enrolled in this study. Their mean age was 48.8 years (32 – 59 years), and their mean weight was 61.5 ± 5.8 kg (50 – 72 kg) and BMI was 23.8. The mean interval from primary to revision THA was 9.5 ± 3.2 years (3.3 – 16.1 years). The preoperative diagnoses for primary THA were osteonecrosis of the femoral head in 31 hips, neglected femoral neck fracture in 3, rheumatoid arthritis in 2, degenerative osteoarthritis in 2, pyogenic arthritis in 2, tuberculosis arthritis in 1, and fused hip in 1. Dissociation of PE liner was observed in 21 hips (50%). For acetabular cup revision, Trilogy ceramic acetabular cups (Zimmer, Warsaw, IN) were used in 22 hips, EP-FIT plus cups (Plus Orthopedics, Rotkreuz, Switzerland) in 14 hips, and Duraloc Option Ceramic cups (DePuy, Warsaw, IN) in 6 hips. Stems were revised in all hips. The follow-up protocol included radiographic and clinical evaluations, and the mean duration of follow-up monitoring after revision THA was 5.4 ± 1.7 years (3.2 – 8.0 years). At final follow-up examination, clinical outcomes including Harris Hip Score and complications were assessed. All changes in inclination were documented radiographically. The presence of radiolucent lines, vertical or horizontal migration of acetabular cup (> 2 mm), and osteolysis were also evaluated.

Results: At final follow-up evaluation after revision, the average Harris Hip Score was 91.3. There were no revised hips during follow-up period. In 6 hips (14.3%), minor complications were observed: 3 heterotopic ossifications, 2 dislocations, 1 infection. No revision was necessary for the treatment of these complications. There were no hips with radiolucent lines, vertical or horizontal acetabular cup migration or osteolysis during the follow-up period. In 21 hips with bone graft, incorporation of bone graft was observed radiographically at final follow-up examination.

Conclusions: Our data showed that clinical and radiographical outcomes after revision THA using third generation ceramic-on-ceramic bearing were favorable. Revision THA with the use of ceramic-on-ceramic bearing surfaces can be preferentially considered especially in young patients. Further studies with long-term follow-up data are warranted.