Incidence, Risk Factors, and Outcome of Ceramic-On-Ceramic Bearing Breakage in Total Hip Arthroplasty.

<bold>Background: </bold>Ceramic-on-ceramic bearing breakage is a rare but significant complication of total hip arthroplasty. This study aimed to identify risk factors for breakage and to determine the outcome of different revision options.<bold>Methods: </bold>All ceramic-on-ceramic primary total hip arthroplasty procedures reported to the Australian Joint Replacement Registry from September 1999 to December 2019 were included. Procedures were subdivided into alumina or mixed ceramic (alumina/zirconia). All breakages were identified. The association between ceramic type and head size was assessed. Subsequent revision rates were compared and cause of revision assessed.<bold>Results: </bold>There were 23,534 alumina and 71,144 mixed ceramic procedures. Breakage was the reason for 1st revision in 84 alumina (5.27% of all revisions and 0.36% of procedures) and 56 mixed ceramic procedures (2.46% of all revisions; 0.08% of procedures). Alumina had a higher breakage rate than mixed ceramic (HR 2.50 (95% CI 1.75, 3.59), P < .001), and breakage was higher for 36-38mm head sizes using alumina (HR 2.84 (1.52, 5.31), P = .001). 17.8% of 2nd revisions occur by 3 years, due to dislocation, infection, metal-related pathology, and loosening. A neck adapter sleeve did not reduce 2nd revisions. Numbers were too low to compare revision bearing surface options.<bold>Conclusion: </bold>Ceramic breakage has reduced with mixed ceramics but has a 0.79/1000 incidence at 15-year follow-up. It is unclear what the risk factors are for modern ceramics with increasing head size a risk for alumina only. Risk of 2nd revision is high and occurs early. The optimal revision option is unknown. [ABSTRACT FROM AUTHOR]