Abstract
Ceramic bearing fracture is a rare complication following implantation using modern day ceramic bearing materials. Revision bearing options in such cases is debated, with the choice between ceramic-on-ceramic and ceramic-on-polyethylene bearings. Revision to a hard on soft bearing raises concerns about potential catastrophic wear secondary to a third-body reaction caused by the fractured ceramic particles.
Data was collected retrospectively from the NJR, electronic patient records, revision database and picture archiving and communication system. Templating software was used to determine linear wear between first post-operative radiograph and the latest available follow up. Univariate analysis was used to examine patient demographics and the wear rates for revision of ceramic bearing fractures to ceramic on polyethylene components. The intra and inter-rater reliability of wear measurements was calculated.
There were twelve patients identified as meeting the inclusion criteria. The average age at revision was 62 years (54–72). There were 6 liner and 6 head fractures revised to delta ceramic heads and cross-linked polyethylene acetabular components. The most frequently used head size was 32mm. At mean follow up of 3.8 years (0.5 6.1 years), median 4.4 years, linear wear rate was calculated at 0.08± 0.06 mm/year. Both intra-rater and inter-rater reliability was excellent with ICC scores of 0.99 at all timepoints.
Revision to ceramic on polyethylene (CoP) bearings following ceramic fracture does not cause early catastrophic wear at early follow up. It appears safe to use this hard on soft bearing combination, given that wear rates are comparable to what is expected in a primary hip replacement setting. Longer follow up is required to establish if this trend persists.
