International Rates of Patellar Resurfacing in Primary Total Knee Arthroplasty, 2004-2014.

BACKGROUND: Patella resurfacing is performed in >80% of primary total knee arthroplasties (TKAs) in the United States, yet far fewer patellae are resurfaced internationally. Recent registry data have begun to question the long-held belief that patellar resurfacing yields lower revision rates. Multiple current meta-analyses have not shown a difference in patient satisfaction, anterior knee pain, or knee society scores based on patellar resurfacing.
METHODS: We sought to determine how the rates of patellar resurfacing have changed over the past 10 years worldwide (2004-2014). Data were abstracted from the annual reports of 7 national joint registries, literature review, or via direct correspondence with registry administrators.
RESULTS: Average rates of patellar resurfacing from 2004 to 2014 ranged from 4% (Norway) to 82% (United States). The largest decrease in resurfacing rates was in Sweden (15%-2%), whereas the biggest increase was in Australia (44%-59%). In 2010, only 48,367 of 137,813 (35%) primary TKAs from all registries outside the United States were resurfaced. Meta-analyses have demonstrated no difference in anterior knee pain or satisfaction scores but do consistently report increased revision rates for unresurfaced patellae. Recent Swedish registry data, however, showed a reverse trend toward higher revision rates after resurfacing.
CONCLUSION: Despite recent registry data and meta-analyses demonstrating equivalent outcomes among resurfaced and unresurfaced patellae in primary TKA, worldwide trends in patellar resurfacing have changed little over the past decade. Most countries outside the United States continue to resurface a much smaller proportion of patellae.