Seven years from now it is very likely there will not be enough surgeons in the US to perform the estimated 427,500 total hip and 1,046,000 total knee arthroplasties that patients will need, according to study findings presented this week at the American Academy of Orthopedic Surgeons (AAOS) annual meeting in Las Vegas.

The report estimates that in 2016, orthopedic surgeons will be able to perform just 231,071 hip replacements and 287,759 knee replacements, which falls 46 percent and 72 percent short, respectively, of the numbers demanded.

Senior author Dr. Thomas K. Fehring told Reuters Health that in the next decade there will likely be a "perfect storm" for access to joint replacement surgery.

On the demand side, "the baby boomers will be entering the years in which joint replacement is common," noted Fehring, from OrthoCarolina Hip and Knee Center, Charlotte, North Carolina. "We have an obesity epidemic in the United States that will affect the need for joint replacement, as obesity increases the need for joint replacement."

At the same time, he added, surgeon supply is falling. "Because of declining reimbursement, young surgeons are not entering the field. Reimbursement for joint replacement has decreased 60 percent in inflation-adjusted dollars since 1990."

"Unless things change, (these forces) will lead to excessive waiting times for our senior citizens requiring joint replacement. Wait times of 1 to 2 years may ensue, which will be unacceptable to the general public."

To estimate the workforce that will be available in 2016, Fehring's team analyzed data from the AAOS database, which includes information on the number of graduating orthopedic residents, the ages of surgeons with a hip or knee focus, and the average retirement age of surgeons. This information, coupled with census data, was used to generate an economic supply and demand model.

The authors calculate that there will be 5038 orthopedic surgeons who will perform hip and knee replacements in 2016. The supply numbers were calculated by multiplying this workforce by the average number of hip and knee replacements performed each year by either a hip and knee specialist or by a generalist with a hip or knee focus.

As for a solution to the supply-side crisis, Fehring said that "a viable pragmatic option that would maintain access for future arthritis patients would be for the government to allow balance billing. This solution may draw young surgeons into the field of arthroplasty, encourage general orthopedists to share in the increased demand for arthroplasty, and encourage established arthroplasty surgeons to practice longer at their current rate of production."