The Benefits of a Muscle-Sparing Below Knee Amputation in the Elderly Population

It is well accepted that good muscle coverage of the bones at the end of a below knee amputation (BKA) stump is preferable, for both weight bearing and protection against prosthesis failure. Elderly patients often have atrophy of the leg musculature secondary to age-related physiological changes and decreased use. These patients often have poor coverage and bulk in their stumps after the standard BKA. We propose a selective muscle-sparing approach to these patients, utilizing selective removal of muscle bundles with regard to their blood supply and fascial planes. The surgical method technique along with outcomes of patients undergoing the procedure is presented here.

A retrospective chart review was performed to identify patients who had undergone a muscle-sparing BKA from March 2008 to October 2017 by a single surgeon. Estimated blood loss, operative time, and perioperative and postoperative complications were assessed.

Forty-six patients greater than 60 years of age underwent muscle-sparing BKA procedures. Complete healing was seen in 30 (65%) patients, while 7 (15%) were lost to follow-up and 9 (20%) required conversion to an above knee amputation (AKA). Intraoperative outcomes in our series were notable for an average estimated blood loss (EBL) of 84.3 ml, lower than the traditional BKA (average EBL 150-500 ml), with comparable operative times averaging 131 minutes and as short as 85 minutes (skin incision to dressing). No patients in the cohort required postoperative blood transfusions (day 0-4), significantly less than the reported 3-7 ml/kg body weight blood requirements in similar patient populations.

The muscle-sparing BKA technique should be considered in elderly patients, where the normally bulky posterior calf muscle mass is lacking. The selective removal of muscle bundles with regard to their blood supply leaves maximum coverage of the bone with decreased potential hematoma formation and blood loss.