Physicians and federal investigators are concerned about a dramatic surge in Medicare spending for artificial feet for beneficiaries.

While the number of diabetes-related lower limb amputations is falling, Medicare spending on artificial feet grew 60% in the last few years, according to an Associated Press investigation. Medicare paid $94 million for artificial feet in 2010.

A report by the Health and Human Services Office of the Inspector General last year found that improper billing practices for these types of prostheses were widespread. A Medicare spokesman told the AP that the Centers for Medicare & Medicaid saved $867,000 in the past year by cracking down on artificial limb fraud.

Rehabilitation advocacy groups contend that anyone who needs prosthetic limbs following an amputation is entitled to them. But rehab physicians question whether these types of devices should be given to people whose mobility is already seriously impaired by other conditions.

An AP analysis of data from Avalare Health found that the spike in Medicare spending is related to “a shift in the types of prosthetics being given to Medicare beneficiaries, from ones that cost several hundred dollars to more sophisticated types that run in the low thousands.”