Researchers reported that ceramicised metal on highly crosslinked polyethylene and ceramic on antioxidant highly crosslinked polyethylene were associated with the lowest risk of reoperation following cementless and hybrid total hip arthroplasty (THA) compared with other bearing surfaces in a large observational analysis of UK registry data.
The researchers analyzed data from the UK National Joint Registry linked with Hospital Episode Statistics to evaluate 696,013 primary THAs performed between 2003 and 2020 using cementless acetabular components with either cementless or cemented femoral stems. Linkage with the hospital database enabled identification of surgically treated periprosthetic fractures that did not require implant revision, providing a more comprehensive assessment of reoperation. Patients were followed for a mean of approximately 5 to 10 years depending on bearing combination, with a maximum follow-up of 19.1 years. The primary outcome was reoperation for any reason, while secondary outcomes included revision for aseptic loosening and reoperation for periprosthetic fracture. Analyses accounted for competing risks, including death.
Among all bearing combinations, ceramicised metal on highly crosslinked polyethylene and ceramic on antioxidant highly crosslinked polyethylene demonstrated the lowest cumulative probability of reoperation during follow-up. After adjustment, ceramicised metal on highly crosslinked polyethylene was associated with about a one-third lower adjusted risk of revision for any reason compared with conventional metal-on-polyethylene, followed closely by ceramic on antioxidant highly crosslinked polyethylene.
In analyses restricted to contemporary bearing surfaces, ceramicised metal on highly crosslinked polyethylene remained associated with the lowest risk of reoperation for any reason, followed by ceramic on antioxidant highly crosslinked polyethylene and ceramic on highly crosslinked polyethylene. Younger age, male sex, cementless stem fixation, and femoral head sizes of 28 mm or smaller were associated with a higher risk of revision.
For aseptic loosening, ceramicised metal on highly crosslinked polyethylene was associated with the lowest risk of revision, with ceramic on antioxidant highly crosslinked polyethylene also demonstrating favorable performance. In the analysis of reoperation for periprosthetic fracture, ceramic on antioxidant highly crosslinked polyethylene had the lowest estimated risk, although ceramic-on-ceramic and ceramic on highly crosslinked polyethylene also performed favorably compared with the reference bearing. Older age, larger femoral head size, and cemented stem fixation were associated with a higher risk of reoperation for periprosthetic fracture.
The linkage with Hospital Episode Statistics identified an additional 1,278 surgically treated periprosthetic fracture fixation procedures that were not captured through registry revision data alone, representing approximately 7% of all reoperations in the complete cohort. According to the investigators, incorporating these procedures provided a more complete estimate of reoperation following THA.
The researchers noted several limitations. Because the study was based on observational registry data, residual confounding could not be eliminated, and the findings cannot establish causation. In addition, ceramicised metal on highly crosslinked polyethylene and antioxidant highly crosslinked polyethylene bearings were limited to relatively few manufacturers and implant combinations, which may have influenced the observed associations. Hospital Episode Statistics also captured only National Health Service-funded procedures performed in England, and nonoperatively managed periprosthetic fractures were not included.
Overall, the findings suggest that certain highly crosslinked polyethylene bearing combinations may be associated with lower long-term reoperation rates following cementless and hybrid THA, although the authors emphasized that the observed differences should be interpreted in the context of the study's observational design. "Small absolute risk differences seen in observational registry data should be weighed against other factors including cost, availability, and surgeon familiarity," wrote lead study author Edward T. Davis, FRCS(Tr&Orth), of The Royal Orthopaedic Hospital NHS Foundation Trust, Birmingham, United Kingdom, and colleagues.
Disclosures: The authors reported that disclosure forms are available with the published article.
Source: JBJS Open Access
