Below-Knee Amputation Failure and Poor Functional Outcomes Are Higher Than Predicted in Contemporary Practice

Abstract

Despite a perceived functional bias toward knee salvage at the time of major amputation, most patients failed to postoperatively ambulate. Those with decreased TcPO2 levels (<40 mm Hg) have a 2-fold higher risk of AKA conversion or death, while nearly one-fourth of all BKA patients will succumb to the same fate irrespective of TcPO2. This suggests that many BKA patients in the endovascular era fail to derive the perceived benefit of knee salvage at the time of their index amputation. These findings highlight the need for careful patient selection and for a shared decision-making model in this frail population.

Predicting reamputation risk in patients undergoing lower extremity amputation due to the complications of peripheral artery disease and/or diabetes

“…Amputation‐level decision‐making in the context of diabetes and peripheral artery disease (PAD) is extremely challenging. The preservation of mobility and its impact on quality of life are key considerations. The goal of preserving mobility has led to a focus on attempting the most distal amputation procedure possible: preserving the knee joint by performing a transtibial (TT) rather than a transfemoral (TF) amputation, or by attempting a limb salvage transmetatarsal (TM) amputation rather than a major amputation.…”

“…The preservation of mobility and its impact on quality of life are key considerations. The goal of preserving mobility has led to a focus on attempting the most distal amputation procedure possible: preserving the knee joint by performing a transtibial (TT) rather than a transfemoral (TF) amputation, or by attempting a limb salvage transmetatarsal (TM) amputation rather than a major amputation. The importance of preserving extremity length by performing more distal amputations, especially at the TM level, has been questioned because of the associated risk of healing failure and the uncertainty about potential mobility advantages.…”

“…The goal of preserving mobility has led to a focus on attempting the most distal amputation procedure possible: preserving the knee joint by performing a transtibial (TT) rather than a transfemoral (TF) amputation, or by attempting a limb salvage transmetatarsal (TM) amputation rather than a major amputation. The importance of preserving extremity length by performing more distal amputations, especially at the TM level, has been questioned because of the associated risk of healing failure and the uncertainty about potential mobility advantages. Failure of primary healing results in the need for additional reamputation surgery and/or prolonged wound care with restricted ambulation which may adversely affect future mobility and increase the risk of death.…”

The Role of Lower Extremity Amputation in Chronic Limb-Threatening Ischemia

“…70 A separate study found that 25% of BKAs ultimately required conversion to an AKA. 71 Functional outcomes following major amputation are largely dependent on preoperative comorbidities and functional status. Younger, ambulatory patients with fewer comorbidities can generally be expected to have functional outcomes similar to those with successful revascularization.…”

Resting TcPO2 levels decrease during liner wear in persons with a transtibial amputation

“…This permits noninvasive evaluation of microcirculation in a local region through analysis of TcPO2 [14][15][16]. TcPO2 is commonly used as a predictor for wound healing potential in ulcer cases or for the determination of adequate amputation levels [17][18][19][20][21][22][23][24][25]. For example, a TcPO2 value of <40 mmHg has been associated with poor healing outcomes in persons with a transtibial amputation and a two-fold higher risk in requiring conversion to a transfemoral amputation [20].…”