Early and Long Term Outcomes Following Long Posterior Flap vs. Skew Flap for Below Knee Amputations

Abstract

Objective: To compare outcomes between long posterior flap (LPF) and skew flap (SF) amputation over a 13 year period.

Methods: This was a retrospective observational cohort study. Consecutive patients undergoing a LPF or SF below knee amputation (BKA) over a 13 year period at one hospital were identified. Both techniques were performed regularly, depending on tissue loss and surgeon preference. The primary outcome was surgical revision of any kind. Secondary outcomes included revision to above knee amputation (AKA), length of hospital stay (LOS), and mortality. A smaller cohort of patients who were alive and unilateral below knee amputees were contacted to ascertain prosthetic use and functional status.

Results: In total, 242 BKAs were performed in 212 patients (125 LPF and 117 SF; median follow up 25.8 months). Outcomes for the two groups were equivalent for surgical revision of any kind (27 LPF vs. 31 SF; p = .37), revision to an AKA (18 LPF vs. 14 SF; p = .58), LOS (29 days for LPF vs. 28 days for SF; p = .83), and median survival (23.9 months for LPF vs. 28.8 months for SF; p = .89). Multivariable analysis found amputation type had no effect on any outcome. Functional scores from a smaller cohort of 40 unilateral amputees who were contactable demonstrated improved outcomes with the LPF vs. the SF (p = .038).

Conclusion: Both techniques appear equivalent for rates of surgical residual limb failure. Functional outcomes may be better with the LPF.

Keywords: Below knee amputation; Long posterior flap; Skew flap.