Ipsilateral third amputation following lower extremity index amputation for diabetic foot infection

Abstract

Background

Lower extremity amputations (LEA) are serious complications of the infected diabetic foot. Subsequent amputations are underreported and the occurrence of an ipsilateral second re-amputation (third amputation) is unknown.

Methods

This is a retrospective study of a continuous series of patients admitted for LEA due to diabetic foot complications, with a minimum of 2 years of follow-up after the first re-amputation. A total of 111 patients comprising 149 index amputation; 97 and 52 cases in the minor and major type groups, respectively. The primary outcomes were the observed frequencies of first and second re-amputations with comparative analysis based on amputation type. Logistic regression analysis was used to look for independent risk factors.

Results

Out of 149 index LEA cases, 111 cases (74.5%) had no re-amputation. First re-amputation frequencies were 25.5%, 35%, and 7.7% for the whole sample, minor, and major groups, respectively. Second re-amputation frequencies were 34.2%, 31.6%, and 2.6% for the whole sample, minor, and major groups, respectively. Infection re-occurrence was the cause in 89.5% and 100% of cases for first and second re-amputation. Out of the 13 second re-amputation cases in the minor group, 30.7% were minor and 69.3% were major amputations. The mean time for the first re-amputation was 5.4 ± 9.4 months and that for the second re-amputation was 9.5 ± 7.1 months (p = .04). For the first re-amputation, independent risk factors were smoking (p = .04) and creatinine level (p = .02) outcome. For the second re-amputation outcome, male sex was the only independent variable (p = .03).

Conclusion

This study demonstrated that a second re-amputation, mostly major, was needed in more than one-third among first re-amputation cases. Second re-amputation could be a relevant major endpoint outcome in this frail population.