Benchmark Data on Aseptic Revision after Knee Replacement

The main advantage of joint registries is their large number of recorded procedures, ideally with very few patient “types” not represented in the database. This is the case with the Australian Orthopaedic Association National Joint Replacement Registry, which includes data on almost 100% of all joint replacements performed in Australia since 2002. In the February 20, 2019 issue of The Journal, Jorgenson et al. analyze almost 6,000 major aseptic total knee arthroplasty (TKA) revisions from a cohort of 478,000 primary TKAs registered between 1999 and 2015. This analysis provides robust benchmark data for patients and surgeons, although it comes too late for the 3% of patients who required such a revision surgery within the 15-year study period.

The authors found that fixed bearings were revised for aseptic reasons at a significantly lower rate than mobile bearings (2.7% vs 4.1%, respectively) and that patients <55 years old had an almost 8-fold higher revision rate compared to patients ≥75 years old ( 7.8% versus 1.0%, respectively). The study also found lower aseptic revision rates with minimally stabilized total knee prostheses compared to posterior-stabilized prostheses, and higher aseptic revision rates with completely cementless fixation relative to either hybrid or fully cemented fixation. These are valuable data for arthroplasty surgeons in terms of selecting implants and surgical techniques and for preoperative counseling of patients—especially younger ones. While many of these findings have been previously reported, these registry-based results add significant strength to published data.

Ideally, data such as these would be controlled for confounding variables such as surgeon experience and additional patient-specific variables such as activity demands and medical comorbidities. Still, these data provide useful prosthesis-specific factors for shared decision making with patients. We look forward to more helpful information from this and other national joint registries and encourage the continued growth of similar registries in other subspecialties.

Marc Swiontkowski, MD
JBJS Editor-in-Chief