CMM-311: Knee Replacement/Arthroplasty

Covers partial (unicompartmental), total, and revision knee arthroplasty and isolated polyethylene liner exchange when patients have function‑limiting knee pain (≥3 months; ≥6 months if BMI>40), loss of function, failure of provider‑directed non‑surgical care, and supporting imaging/arthroscopy (e.g., Kellgren‑Lawrence Grade IV or Modified Outerbridge Grade IV or AVN) plus procedure‑specific criteria (e.g., intact/stable ligaments and >90° ROM for unicompartmental; revision indications such as aseptic loosening, infection, periprosthetic fracture, implant/component failure, instability, malalignment, or stiffness; IPE for progressive osteolysis with well‑fixed implants, catastrophic polyethylene failure, or early infection <4 weeks). Not covered when contraindications exist (e.g., active local/systemic infection, inadequate bone stock, severe fixed deformity—partial: flexion contracture >15°, varus >15°, valgus >20°; total: >30° fixed deformity—significant uncorrectable ligament insufficiency, inflammatory arthropathy, Charcot joint, severe uncontrolled comorbidities or immunocompromise); documentation must record symptom duration, imaging/arthroscopy grades, prior conservative treatments (or why not appropriate), implant position/fixation, and timing/details for revisions/IPE.