Indications for and outcomes of major lower limb amputations at a tertiary-referral centre in Australia

Major amputations are classically associated with significant morbidity and mortality. With the increasing prevalence of risk factors for amputation, namely, diabetes and peripheral arterial disease, we sought to identify the major indications for lower limb amputation in an Australian cohort. A secondary aim was to assess the outcomes, namely, mortality, of amputees over the previous decade.

This study assessed all patients undergoing major lower limb amputations between 2012 and 2020. Variables analysed included comorbidities, indication for amputation, in-hospital complications and mortality, duration of hospital stay, and out-patient mortality.

317 amputations were performed on 269 patients. 55% of amputations were below knee, 45% above knee, with one through-knee amputation. Indications included ischaemia (55.2%), infection (30.6%), malignancy (6.9%), trauma (4.4%), and chronic pain or instability (2.5%). In-patient mortality rate was 7.6%, with mortality rates of 21.5% at one year, and 70.1% at 10 years. Post-operative complications occurred in 43% of amputations. Rural, regional, and remote (RRR) patients did not suffer disproportionately from major amputations, however, were more likely to require amputations for ischaemia. Patients undergoing amputation for infective causes demonstrated lower mid-term mortality rates compared to those undergoing amputations for ischaemia (56.1 vs 60.4% at 5 years, p = 0.007).

Major amputations continue to be associated with significant morbidity and mortality, both in the short and long term. Patients undergoing amputations for ischaemic causes demonstrate poorer outcomes than their infective counterparts, with outcomes being even worse in RRR populations. Prevention of amputations via intense management of comorbidities would benefit both patients and the healthcare system.