Continuous Passive Motion (CPM) Machines

Aetna covers CPM machines as an adjunct to ongoing physical therapy for post‑operative rehab after total knee arthroplasty (including revisions), for surgical release of arthrofibrosis/adhesive capsulitis, following manipulation under anesthesia of joints, and to promote cartilage healing during the non‑weight‑bearing phase after abrasion/microfracture or autologous chondrocyte transplantation, but finds use for other indications or beyond recommended durations unsupported. To be medically necessary CPM must start within 2 days of surgery, is typically used 7–10 days (up to 21 days on individual consideration), must stop once the patient begins active PT or weight‑bearing, and sheepskin pads are integral to the device and not separately reimbursable.

"Aetna considers CPM machines experimental, investigational, or unproven for rehabilitation following back surgery."