A total knee replacement (TKR) is a common way to stop the pain and loss of motion from arthritis or other conditions affecting the knee. Occasionally problems occur, and the leg has to be removed or amputated. The loss of limb isn't always related to the TKR. Other problems such as tumors or poor circulation are sometimes at fault.

How often does this happen? Until recently the answer to this question was unknown. Doctors at the Mayo Clinic read the charts of over 18,000 patients from the last 30 years. They report that 0.36 percent of the patients receiving a new knee joint later had the leg amputated above the knee.

The amputations were done an average of eight years after the knee replacement procedure. For some patients, removing the leg had to be done as early as eight days afterward. For another patient, it wasn't until almost 24 years later.

Most of the amputations (nearly 65 percent) were for causes other than the TKR. Only 25 of the 18,443 patients had the amputation for reasons directly linked to the TKR.

When a TKR fails, the doctor can usually revise the implant in a second operation. But when chronic infection sets in or severe bone loss occurs, the leg may have to be removed. Amputation is always a last resort. And the results of this large study show that amputation after TKR doesn't happen very often.

Reference:

Rafael J. Sierra, MD, et al. Above-the-Knee Amputation after a Total Knee Replacement. In The Journal of Bone and Joint Surgery. June 2003. Vol. 85-A. No. 6. Pp. 1000-10004.'