Appropriateness Criteria for Total Knee Arthroplasty: Additional Comments and Considerations.

Appropriateness classification for total knee arthroplasty (TKA) has received substantial attention recently, and Katz and colleagues published an Orthopaedic Forum on the topic in The Journal of Bone & Joint Surgery in February 2017. Classifications of appropriateness are particularly important given the rapid rise in use of TKA and a variety of third-party payer approaches designed to control health-care costs. We respond to some of the concerns addressed by Katz and colleagues, and elaborate on what we believe are some important issues related to both older and newer appropriateness criteria for TKA.