Revision of failed below knee amputations. Local debridement with gentamicin collagen.

OBJECTIVE: To describe our results with a new technique of revision of failed below knee amputation stumps using gentamicin impregnated collagen sponge. DESIGN: Open study. SETTING: District hospital. SUBJECTS: 31 patients who underwent below knee amputations between 1988 and 1992, compared with 31 historical controls who were operated on between 1984 and 1988. INTERVENTIONS: Two thirds of the stumps that failed to heal underwent excision of necrotic and devitalised tissue; half had shortening of tibia and fibula and a gentamicin impregnated collagen sponge was left in the wound, which was then closed. MAIN OUTCOME MEASURES: Successful wound healing and rehabilitation. RESULTS: 12 Stumps failed to heal, 8 of which were suitable for local treatment with the gentamicin sponge. All 8 healed satisfactorily, though one required revision of the scar 6 months later. Of the remainder, the stumps were converted to above knee amputations (n = 3) and one was disarticulated at the knee. In the control group 5 of the 7 stumps in which healing failed, were converted to above knee amputations and the other two healed after split skin grafting. CONCLUSION: We think that local treatment with the collagen sponge with gentamicin offers a viable alternative to conversion to above knee amputation for below knee amputation stumps that fail to heal. The treatment should now be subjected to a randomised controlled trial.