Acetabular reconstruction with a threaded prosthesis for failed total hip arthroplasty.

The MEC-Ring threaded acetabular component was used in 35 patients for revision of failed cemented hip arthroplasties, and 32 have been observed for two to four years (mean, 2.5 years). With only a short-term follow-up period, 44% of patients have already required revision for failure of the MEC-Ring acetabular component. Patients with especially poor acetabular bone stock that had had structural bone graft had a significantly higher rate of failure. The authors developed a technique of supine oblique roentgenograms that allowed better visualization of the component-bone interface. Eighty-six percent of patients had radiolucencies, and 67% of these were progressive. The presence of progressive radiolucencies, component migration, or both was associated with a higher failure rate. Progressive radiolucencies were also associated with a worse pain score in patients whose arthroplasties have not failed. The MEC-Ring threaded component is not recommended for revision hip arthroplasty, especially in cases with poor acetabular bone stock.