Medium-term result of Elite Plus hip arthroplasty: the second modular evolution of the original Charnley low-friction arthroplasty.

BACKGROUND: The Elite Plus total hip arthroplasty (THA) system was introduced as the second modular evolution of the original Charnley low-friction arthroplasty. However, the results of the Elite Plus THA are currently considered to be inconsistent. The aim of this study was to clarify the medium-term results and the factors affecting the results of Elite Plus THA. METHODS: The results of 97 Elite Plus THAs in 87 patients at 5 years or more postoperatively were reviewed. The patients' mean age was 65 years, and follow-up averaged 8.0 years. The Elite Plus stem was used in all hips, and three designs of socket, Hylamer Ogee in 40 hips, Wroblewski Offset Bore in 38, and Charnley Ogee in 19, were implanted. The survival rates with loosening and revision as endpoints were analyzed. To clarify the risk factors affecting the survival rates, Charnley's functional classification, Bombelli's classification, Crowe's classification, structural bone grafting of the acetabulum, cup design, stem position, and grading of the cement mantle were evaluated. CONCLUSIONS: The results of Elite Plus stem THA were excellent in the medium term. The cup design was a potential confounding factor for acetabular loosening, and the Hylamer Ogee socket was associated with a poor result.

Poor results of the cementless total hip arthroplasty with a nonporous coated acetabular component: AcSys Shearer Cup.

BACKGROUND: This study followed patients for a minimum of 7 years after primary total hip arthroplasty using cementless acetabular components and evaluated their outcomes. METHODS: We followed 73 patients (75 hips), who had undergone total hip arthroplasty with cementless nonporous coated acetabular components (3M AcSys Shearer Cup) for a mean of 9.8 years (range 7-13 years). There were 61 women and 12 men with a mean age of 53 years (range 27-69 years) at surgery. The diagnosis was primary osteoarthritis in 9 hips, osteoarthritis secondary to developmental dysplasia in 58 hips, osteonecrosis of the femoral head in 6 hips, and rheumatoid arthritis in 2 hips. RESULTS: Three cups were revised because of aseptic loosening, and one cup was revised following removal of the prosthesis due to deep infection. Radiographic loosening was observed in 22 hips at the latest follow-up. The survival rate at 10 years was 94.7% with revision as the endpoint and 72% with radiographic loosening as the endpoint. The Merle d'Aubigné and Postel hip score showed significant improvement postoperatively and was maintained well even in cases showing radiographic loosening. CONCLUSIONS: The intermediate radiological results with the AcSys Shearer Cup were unsatisfactory because of the high loosening rate, although the revision rate was low. The nonporous outer surface and the poor fixation mechanism between the metal shell and liner may have contributed to the high failure rate. Regular radiological review is recommended when this cup is used because early loosening is often painless.