Burgess et al. prospectively measured segmental transcutaneous oxygen tension (tcPO2) at multiple limb levels in 37 dysvascular patients undergoing below-knee amputation. The study asked whether preoperative tcPO2 at the proposed amputation site could predict wound healing — and what threshold reliably separated healers from failures.
Before this paper, amputation level selection depended entirely on subjective clinical signs — skin color, capillary refill, hair growth, bleeding at incision. None of which provided a reliable quantitative threshold. Doppler ischemic ratios were proposed as an objective alternative, but failed in patients with calcified arteries and no detectable pulse, a common scenario in end-stage peripheral vascular disease.
This paper established 40 mmHg as the first objective, non-invasive, quantitative threshold for below-knee amputation level selection. When you see a dysvascular patient with tcPO2 ≥40 mmHg below the knee, proceed with BKA confidently. When tcPO2 is zero, plan for above-knee amputation from the start. Revision is inevitable.
For the intermediate range (>0 to <40 mmHg), the data support attempting BKA in most patients, but counsel them that local revision or proximal conversion remains possible. And that new arterial events, not the measurement itself, drove the failures in this cohort.
This work is foundational to modern amputation surgery: it validated tcPO2 as the preferred objective tool in patients where Doppler fails, and the 40 mmHg threshold remains embedded in amputation planning guidelines decades later.
Burgess et al. prospectively measured segmental transcutaneous oxygen tension (tcPO2) at multiple limb levels in 37 dysvascular patients undergoing below-knee amputation. The study asked whether preoperative tcPO2 at the proposed amputation site could predict wound healing — and what threshold reliably separated healers from failures.
Before this paper, amputation level selection depended entirely on subjective clinical signs — skin color, capillary refill, hair growth, bleeding at incision. None of which provided a reliable quantitative threshold. Doppler ischemic ratios were proposed as an objective alternative, but failed in patients with calcified arteries and no detectable pulse, a common scenario in end-stage peripheral vascular disease.
This paper established 40 mmHg as the first objective, non-invasive, quantitative threshold for below-knee amputation level selection. When you see a dysvascular patient with tcPO2 ≥40 mmHg below the knee, proceed with BKA confidently. When tcPO2 is zero, plan for above-knee amputation from the start. Revision is inevitable.
For the intermediate range (>0 to <40 mmHg), the data support attempting BKA in most patients, but counsel them that local revision or proximal conversion remains possible. And that new arterial events, not the measurement itself, drove the failures in this cohort.
This work is foundational to modern amputation surgery: it validated tcPO2 as the preferred objective tool in patients where Doppler fails, and the 40 mmHg threshold remains embedded in amputation planning guidelines decades later.