Aims. In 2015, we published the results of our ceramic-on-metal (CoM) total hip arthroplasties (THAs) performed between October 2007 and July 2009 with a mean follow-up of 34 months (23 to 45) and a revision rate of 3.1%. The aim of this paper is to present the longer-term outcomes. Methods. A total of 264 patients were reviewed at a mean of 5.8 years (4.6 to 7.2) and 10.1 years (9.2 to 10.6) to determine revision rate, pain, outcome scores, radiological analysis, and blood ion levels. Those who were unwilling or unable to travel were contacted by telephone. Results. The all-cause revision rate at six years was 3.1% (eight THAs), increasing to 8.8% (18 THAs) at ten years. Of these, there were four and then seven bearing-related revisions at six and ten years, respectively. There was a statistically significant deterioration in the visual analogue scale pain score and Oxford Hip Score (OHS) between six and ten years. There were 18 CoM THAs in 17 patients who had a cobalt or chromium level over 4 ppb and ten CoM THAs in nine patients who had a cobalt or chromium level higher than 7 ppb with a statistically significant increase in chromium levels only between the two timepoints. Overall, 84 stems (39.1%) had significant radiolucent lines at ten years compared to 65 (25.5%) at six years. Conclusion. When compared to the original review, there has been a significant deterioration in pain score, OHS, radiograph appearance, and, most critically, survival has fallen to 91.2%, which does not meet the Orthopaedic Data Evaluation Panel (ODEP) 10 A* 95% threshold. Although this bearing is no longer on the market, 2.5% were bearing-related revisions, which have relevance to the discussion around modular dual-mobility implants that have a similar metal interface

Aims. In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component. Methods. Between 2012 and 2020, across two centres, 94 patients underwent revision of Birmingham MoM hip arthroplasties or resurfacings. Mean age was 65.5 years (33 to 87). In 53 patients (56.4%), the acetabular component was retained and dual-mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). Patients underwent follow-up of minimum two-years (mean 4.6 (2.1 to 8.5) years). Results. In the DM group, two (3.8%) patients underwent further surgery: one (1.9%) for dislocation and one (1.9%) for infection. In the AR group, four (9.8%) underwent further procedures: two (4.9%) for loosening of the acetabular component and two (4.9%) following dislocations. There were no other dislocations in either group. In the DM group, operating time (68.4 vs 101.5 mins, p < 0.001), postoperative drop in haemoglobin (16.6 vs 27.8 g/L, p < 0.001), and length of stay (1.8 vs 2.4 days, p < 0.001) were significantly lower. There was a significant reduction in serum metal ions postoperatively in both groups (p < 0.001), although there was no difference between groups for this reduction (p = 0.674 (cobalt); p = 0.186 (chromium)). Conclusion. In selected patients with Birmingham MoM hips, where the acetabular component is well-fixed and in a satisfactory position with no surface damage, the metal head can be exchanged for polyethylene ADM/MDM bearings with retention of the acetabular prosthesis. This presents significant benefits, with a shorter procedure and a lower risk of complications. Cite this article: Bone Jt Open 2024;5(6):514–523