HCPCS Level II code L1845 describes a prefabricated knee orthosis, double upright, thigh and calf, with adjustable flexion and extension joint (unicentric or polycentric) and medial-lateral and rotation control, customized by trimming, bending, molding, assembling, or other adjustment to fit a specific patient; the service represents provision and patient-specific customization of an orthotic device used for knee stabilization and joint control, typically classified as durable medical equipment and provided in an outpatient clinic, orthotics/prosthetics supplier, or hospital outpatient setting.