Abstract
Introduction
The American Joint Replacement Registry (AJRR) was created to capture total hip (THA) and total knee arthroplasty (TKA) procedural data in order to conduct implant-specific survivorship analyses, produce risk-adjusted patient outcome data, and provide hospitals and surgeons with quality benchmarks. The purpose of this study is to compare early reports from the AJRR to other national registries to identify similarities and differences in surgeon practice and potential topics for future analysis.
Methods
Hip arthroplasty data were extracted from the annual reports from the AJRR and other national registries including: the Australian registry; the New Zealand registry; the United Kingdom, Wales, and Isle of Man registry; the Norwegian registry; and the Swedish registry from 2014 to 2016. Data regarding femoral and acetabular fixation, bearing surface type, femoral head size, the use of dual mobility articulation bearings, hip resurfacing utilization, and THA revision burden were evaluated. Revision burden is defined as the ratio of implant revisions to the total number of arthroplasties performed in a given time period. Registry characteristics and patient demographic data were recorded across all registries. The results were compared between the various registries and reported using descriptive statistics.
Results
In 2016, the AJRR captured data from approximately 28% of all arthroplasty procedures performed in the United States, compared to 95–98% amongst the other registries that were evaluated. Total hip arthroplasty patients in the AJRR were similar to the other registries, with a mean age of 66.6 years for primary THA compared to a range of 67.0–69.0 years amongst the other registries. The operative diagnoses varied for primary THA between the registries. Osteoarthritis was the most common diagnosis but it represented 93% of patients in the UK and Wales registry,
79% in the AJRR and 76.5% in the Norwegian registry. THA practices in the AJRR revealed much higher usage of cementless femoral and acetabular components (93%). In comparison, the other registries reported variable rates of usage of cementless femoral and acetabular fixation including: Australian registry (63.4%); United Kingdom and Wales (38.5%); New Zealand registry (39.1%) and the Swedish registry (21.8%). In the AJRR ceramic heads (52.8%) and 36mm heads (60.2%) were most frequently used; in all other registries metal heads (52.7–69.4%) and 32mm heads (37.0–72.7%) were the most popular. Dual mobility articulations were infrequently reported by the other registries but accounted for 8% of primary THAs and 28% of revision THAs in the AJRR. In 2016 the THA revision burden was 8.6% in the AJRR compared to 8.2 – 13.8% in the other registries.
Conclusion
The present study offers an early comparison of data reported by the AJRR and other national registries and identifies several differences in THA practice patterns between the United States and other countries. As the AJRR continues to grow, future studies should focus on understanding why international differences in total joint arthroplasty practice trends exist and differences in outcomes associated with these practices.
