CMM-311: Knee Replacement/Arthroplasty

CMM‑311 covers partial (medial/lateral/patellofemoral) and total knee arthroplasty, revision arthroplasty, and isolated polyethylene liner exchange when patients have function‑limiting knee pain (≥3 months, ≥6 months if BMI>40), loss of function, severe degenerative disease documented by Kellgren‑Lawrence Grade IV or Modified Outerbridge Grade IV (or equivalent arthroscopic/radiographic findings), and failure of provider‑directed non‑surgical management (or documented reason non‑surgical care is inappropriate); partial UKA additionally requires intact/stable ligaments (especially ACL) and knee arc of motion >90°, with specific criteria for revision and IPE. Exclusions include active local/systemic infection, inadequate bone stock, severe deformity or ligament insufficiency, Charcot joint and other listed absolute/relative contraindications, and coverage decisions require documentation of symptom duration, prior conservative therapies (or rationale), imaging findings, BMI and relevant exam/imaging details.