CPT Code 27447: Total Knee Arthroplasty

The CPT code for total knee arthroplasty is 27447. This code represents the surgical replacement of the entire knee joint with a prosthetic implant, typically performed to relieve pain and restore function in patients with severe arthritis or joint degeneration.

CPT 27447 refers to total knee arthroplasty, where all three compartments of the knee—medial, lateral, and patellofemoral—are replaced. In contrast, CPT 27446 is used for unicompartmental (partial) knee arthroplasty, which replaces only one compartment of the knee, usually the medial or lateral side.

No, CPT 27447 is not inpatient-only. While total knee arthroplasty has traditionally been performed in inpatient settings, many payers—including Medicare—now allow it in outpatient settings when the patient meets clinical and safety criteria. Surgical setting should be based on medical necessity and payer guidelines.

‍