Appeal type: Medical necessity
Decision: Overturned

Diagnosis: Status post amputation
Treatment: Knee Prosthesis (L5050, L5618, L5940, 
L5629, L5637, L5668, L5632, L5636, L5910, L8420, L8470)
The insurer denied:  Knee Prosthesis (L5050, L5618, L5940, 
L5629, L5637, L5668, L5632, L5636, L5910, L8420, L8470)
The denial is overturned.

The records indicate that the patient is an adult female with a history that includes diabetes mellitus. Last year, she underwent a left foot amputation. A month later, she underwent a left lower extremity open debridement, Symes amputation (for example (i.e.), ankle 
disarticulation), and secondary closure due to complications related to infection. Nine months ago, she underwent further left ankle debridement and secondary closure. She was provided a 
postoperative fiberglass walking cast with rubber bottom. She had "excellent" subsequent healing without soft tissue breakdown and "good" gait with "good" balance and "very good" weight-bearing capacity at the left residual limb with her walking cast and a walker. The patient was deemed to be a Medicare K3 (ability or potential to ambulate with variable cadence) class ambulator. A definitive Symes prosthesis with total surface bearing socket with replaceable medial window for donning/doffing and a low profile K3 (ability or potential to 
ambulate with variable cadence) class carbon fiber foot was prescribed. The health plan denied coverage of the service under review, indicating that the service is a "custom" prosthetic device with "enhanced features" that was not medically necessary, as the patient's activities of daily living needs could be met with "standard" prosthetic devices. The reason for appeal is that the requested prosthesis is needed to continue advancement of her mobility skills and that any prosthesis with less than the proposed componentry would negatively impact her mobility and function.

The requested prosthesis and add-on codes in question (i.e., L5050, L5981, L5618, L5940, L5629, L5637, L5668, L5632, L5636, L5910, L8420, and L8470) are medically necessary.

The patient has healed sufficiently from her left lower extremity Symes amputation for a definitive prosthetic limb. The proposed prosthesis and add-on codes constitute the most basic prosthesis appropriate for the patient's needs. While her most basic mobility-related activities of daily living can be accomplished on a short-term basis without a prosthesis where she can bear weight on the residual lower extremity, this is not efficient over longer distances, especially in the community, nor is it appropriate long-term due to risk of breakdown. A total surface bearing socket will disperse the pressure over a larger surface area. The medial window adaptation is necessary for donning and doffing due to the bulbous end of the residual limb (which is a natural end result of a Symes ankle disarticulation amputation). The carbon fiber K3 (ability or potential to ambulate with variable cadence) foot is a standard terminal device for this amputation level given the patient's functional abilities for energy efficiency during gait. The ultralight materials are also necessary and appropriate to optimize efficiency, particularly during community mobility. Therefore, the requested health service is medically necessary.