Wertli MM, Schlapbach JM, Haynes AG, et al. - Researchers investigated the regional variation in hip (HA) and knee arthroplasty (KA) rates. In addition, they determined potential determinants of variation in Switzerland. Using discharge data from all Swiss hospitals during 2013–2016, they conducted a population-based analysis including 69,578 HA and 69,899 KA from 55 hospital service areas. The mean age-/gender-standardized HA rate of 265 (range 179–342) and KA rate of 256 (range 186–378) per 100,000 persons were observed; increase in these rates was noted over time. Observations thereby suggest high HA/KA rates in Switzerland with a modest regional variation; this indicates that the threshold to perform HA/KA may be uniformly low across regions. One third of the variation remained unexplained; this may, at least in part, represent differences in physician beliefs and attitudes towards joint arthroplasty.