Skew flap versus long posterior flap on below-knee amputation in patients with peripheral vascular disease

Abstract

Background/Aim: Below-knee amputation (BK) is the most proximal amputation that is still associated with a good rehabilitation procedure. All variations of the transtibi al amputation are designed to provide adequate distal end padding and produce a cylindrical stump that can be readily suitable for prosthesis. The aim of this study is to compare the skew flap and the long posterior flap below-knee amputation in patients with peripheral vascular disease in terms of stump healing, wound infection, reamputation rate, and mobility with a prosthetic limb as outcome measures. Patients and methods: Fifty patients with chronic atherosclerotic occlusive disease of the lower extremity and critical ischemia (intractable rest pain, ulcer or gangrene) for whom no other treatment options remained and in whom below-knee amputation is indicated are included in the study. Patients were randomized into two groups. Group 1 underwent Skew Flap BKA; Group 2 underwent long posterior flap BKA. The two groups will be compared in terms of stump healing, wound infection, prosthesis fitting rate, and mobility with a prosthetic limb. Statistical analysis by Chi-square and t-test was used to compare two groups as regard quantitative variables in parametric data (SD<25% mean). Results: Regarding the early post-operative outcomes in terms of death in the 30 days post­ operative period, incidence of cardiac events within 30 days post-operatively, primary healing after 7 days, wound discharge after 7 days, incidence of minor edge necrosis after 7 days, major flap necrosis after 7 days, revision of stump & post-operative stay period. Comparing the 2 tested groups using the Chi square showed no significant statistical differences between both of them. Regarding the late outcome results including the survival within 6 months, among the 25 patients of group 1, 20 patients survived till 6 months postoperatively (80% survival rate), while among the 25 patients of group 2, 18 patients survived till 6 months postoperatively (72% survival rate). Regarding prosthesis fitted within 6 months, among the 20 patients of group 1, 5 patients used the below knee prosthesis (25%), while among the 18 patients in group 2, 3 patients used the prosthesis (18.18%). Regarding the mobility status of patients with 6 months post-operative: among the 20 patients of group 1, among 20 patients of group 1, 3 patients were immobile (16.67%), 12 patients were dependent (60%), and 5 patients were independent (25%). While among the 18 patients of group 2: 2 patients were immobile (11.11%), 13 patients were dependent (72.22%) and 3 patients were independent (16.67%). By comparing the two groups regarding the mobility status within 6 months post-operative, there was no significant statistical difference using Chi square. Conclusion: The skew flap technique is considered the routine procedure for below knee amputation in many centers around the world. We conclude that the skew flap is just as effective as the long posterior flap. Skew flap is especially useful when below knee amputation is indicated and the posterior skin is inadequate to construct a long posterior flap.