Editorial Comment: Selected Papers from the 9th International Congress of Arthroplasty Registries

Considering the overall favorable results in terms of implant survival, pain relief, and improved function following hip and knee replacement, is there still a need for arthroplasty registers? My answer is: unquestionably yes.

Continued high-quality care and further improvements in joint replacement require continuous monitoring and outcome assessment using arthroplasty register data. The large sample sizes allow early detection of small but clinically important differences in implant survivorship [⁵], as well as insights into performance of different surgical methods and implant concepts (such as hooded vs. nonhooded liners [¹]), and identification of high-risk patient subgroups [¹³]. It would take years longer to identify these kinds of differences in clinical trials, and because of daunting logistical challenges—the need for unrealistically large numbers and long surveillance periods—many or most of those trials probably would never be performed. Yes, registry research remains essential if we are to keep our patients safe.

Despite the pandemic, the International Society of Arthroplasty Registries (ISAR) has continued its mission of improving outcomes following joint replacement worldwide. To achieve progress, the work within ISAR is organized into subcommittees focusing on different areas of development. Currently, ISAR subcommittees cover benchmarking, patient-reported outcomes measures (PROMs), signal detection (that is, the rapid and early detection of underperforming implants and methods), education, and statistical methodology.

In the Proceedings of the 9^th International Congress of Arthroplasty Registries in this issue of Clinical Orthopaedics and Related Research®, we see a fine example from the PROMs working group, demonstrating how these subcommittees strive to reach development, harmonization, and conformity [²]. For many registries, PROMs have become an integral part of the multidimensional assessment of arthroplasty, but not all registries collect them, and they are not measured consistently across registries. The paper by Bohm et al. [²] identified differences but also some important points of consensus that I think will lead to cross-registry data pooling that can help us answer bigger questions even than can be addressed in the context of a single national registry.

The 9^th International Congress of Arthroplasty Registries, which was also the 1^st Annual Virtual Congress, was hosted by the Australian Orthopaedic Association National Joint Replacement Registry, on November 13^th-15^th 2020. The virtual format, of course, required a more condensed program. Nevertheless, this congress had a record-high attendance with more than 200 delegates. The congress covered developments within recurrent focus areas, in alignment with ISAR’s subcommittees, and showcased many of the benefits and necessity of arthroplasty register work.