Is the outlook for the vascular amputee improved by striving to preserve the knee?

A trend to amputate below knee (BK) began in the late 1960's when the disadvantages of above knee (AK) amputation were recognised. In this study, the outcome of 189 consecutive patients who had major lower extremity amputations between 1978-1982 was compared to earlier reports from the same institution. Their cumulative survival of 52% at three years, was similar to the cumulative survival of 116 amputees whose surgery was done in 1966-1971. The risk of losing the second limb, almost 10% per year, was also similar to the earlier experience of 1966-1971. In 1964 one BK amputation was performed for every six above the knee. By 1980 this ratio had reversed to three BK for each AK amputation. When a ratio of BK:AK amputation greater than 2:1 was achieved in our patient population, using clinical criteria as the sole guide to amputation levels, one in four failed. The eventual ratio of healed BK to AK amputation achieved was little better than unity. A trend to below knee amputation was not associated with improvement of long term survival after lower extremity amputation for advanced arterial disease. These results indicate a need for better care of the vascular amputee and for a test to compliment clinical selection of amputation levels.