[Borderline amputations in diabetics--open questions and critical evaluation]

Minor amputations are frequently performed in neuroischemic or neuropathic lesions of the diabetic foot. In German-speaking countries, the term "Grenzzonenamputation" was created to describe the combination of minor amputation exactly in the border zone to vital tissues, necrosectomy and débridement. For early and optimal rehabilitation, as much vital tissue as possible should be conserved, especially the skeletal structures of the foot. "Grenzzonenamputationen" are of utmost importance for the prevention of ascending infections, and they reduce the duration of clinical and outpatient treatment. "Grenzzonenamputationen" should be performed only by experienced surgeons and if the arterial perfusion is sufficient. They should be as tissue-sparing as possible, and structured interdisciplinary postoperative care is mandatory. Controversial opinions exist with respect to the use of tourniquets, conservation or resection of cartilage and sesamoids, open amputation or primary closure of the wound, interdigital spacer function of toes, aseptic proximal transection of tendons, postoperative wound care, and antibiotic therapy. In view of these controversies, the most important distal minor amputations are described and discussed, with special regard to the habitual surgical way of thinking.