RAND study examines health benefits, economic value of advanced transfemoral prostheses

Soeren Mattke

Soeren Mattke


LAS VEGAS — Microprocessor-controlled knees were associated with improved physical function and reduction in falls and osteoarthritis, and met standard criteria in value for money when compared with non-microprocessor-controlled knees, according to research presented here at the American Orthotic & Prosthetic Association World Congress.

Soeren Mattke, MD, MPH, DSc, senior scientist and managing director for RAND Health Advisory Services and professor at Pardee RAND Graduate School, gave a presentation titled, “RAND study: Economic value of advanced transfemoral prosthetics.”

“Advanced prosthetics allow for better mobility, but payers have recently started questioning their value for money,” Mattke told O&P News. “We simulated the differential clinical outcomes and cost of microprocessor-controlled knees (MPKs) compared to non-microprocessor-controlled knees (NMPKs).”

As there was no direct evidence between MPKs and NMPKs, the researchers conducted a simulation study, Mattke said. The researchers conducted a literature review of clinical and economic impacts of prosthetics knees and conducted technical expert panel meetings. After completing input parameters, the researchers implemented a simulation model during a 10-year time period for unilateral transfemoral amputees with Medicare functional classification levels of 3 or 4. The objective of the study was to estimate incremental cost of MPKs compared to NMPKs per quality-adjusted life year.

“This initial attempt to quantify the health and economic impact of MPKs shows promising results,” Mattke said in his presentation.

“Rarely ever do advance technologies save money; that’s extremely uncommon,” he said. “In these comparative effectiveness studies, we are typically not looking for ‘Does the technology save money?’ We are looking for evidence that the incremental cost of the technology is in line with what we spend on other things.”

The results included improvements in health and quality of life, and incremental cost in line with other covered technologies.

Despite some gaps in the study evidence, the researchers were able to quantify two important benefits, according to Mattke. These were that patients with MPKs had a lower risk for falls than the patients with NMPKs and that translated to avoidance of medical care and indirect costs. There was some evidence that the better gait with MPKs translated to patients having a lower risk for developing osteoarthritis in the contralateral leg, he said.

According to an accompanying press release from the American Orthotic & Prosthetic Association, the RAND study showed 26% of patients who received prosthetic limbs with MPKs will fall per year compared with 82% of patients who received non-MPK limbs.

There was “robust” evidence that there was an almost 80% relative risk reduction in falls with both minor injuries and major injuries with MPKs, which translates into lower mortality, Matkke said.

The full study reported that for every 10,000 people, MPKs result in 82 few major injurious falls and 62 few minor falls, which translates to 11 lives saved. Researchers also found that for every 10,000 people, there were 1,630 fewer incidences of osteoarthritis as a result of MPKs.

“Compared to NMPK, MPK is associated with sizeable improvement in physical function and reductions in incidences of falls and osteoarthritis,” Mattke told O&P News. “The incremental cost per quality-adjusted life year gained for MPK is $11,606, which meets standard criteria for value for money and is well within the range of other covered medical technologies.” – Bruce Thiel



Mattke S. RAND study: economic value of advanced transfemoral prosthetics. Presented at: American Orthotic & Prosthetic Association World Congress; Sept. 6-9, 2017; Las Vegas.




Disclosures: The study was sponsored by the American Orthotic & Prosthetic Association (AOPA) and conducted by RAND Health, a division of the RAND Corporation. Mattke reports being employed as a senior scientist and managing director, RAND Health Advisory Services. The researchers note the material contained in the report is the responsibility of the research team and does not necessarily reflect policy positions of AOPA.

Leave a Reply

Your email address will not be published.