CHAPTER 5 Incidence of Partial Knee Arthroplasty
A Growing Phenomenon?
Introduction
While the number of patients with symptomatic osteoarthritis has continued to grow significantly, it appears that the percentage of patients in which the osteoarthritis is confined to predominantly one compartment (and thus amenable to partial knee replacement) has remained relatively constant, and has been estimated at 30%. This chapter reports the incidence of partial knee arthroplasty (PKA) in all countries that have an existing registry. For the United States, which does not have a registry, we have estimated the incidence of unicondylar arthroplasty by indirect methods, using implant sales data from the major manufacturers.1 We have estimated market share by utilizing commercial databases that track market share.2