Historically, diabetic neuropathy is progressive and irreversible. A predictable outcome of this neuropathy is ulceration in one of six diabetics, occurring at a rate of 2.3% per year of diabetic neuropathy. Historically, one of six patients with ulceration will have an amputation. In 1998, there were 88,000 amputations in diabetics. Since 1992, four independent published studies have documented that sensation can be restored to the feet of diabetics by decompression of the posterior tibial nerve. Those studies did not use ulceration and/or amputation as the primary outcome parameters.

The present study evaluated 49 diabetics who had a unilateral decompression of the four medial ankle tunnels (posterior tibial nerve and its branches). The contralateral foot was not decompressed. The glycemic control was therefore the same for both feet. Outcomes were assessed by both a questionnaire and telephone call follow-up.

Data were analyzed using SPSS 9.0 for Windows software. An unfavorable outcome was defined as an amputation or the development of an ulcer. Fisher's exact test was used to test the null hypothesis that the proportions with an unfavorable outcome in the population were the same; that is, that operated extremities were equally likely to develop unfavorable outcomes as non-operated extremities.

At a mean of 4.5 years after surgical decompression, there were no ulcerations and no amputations to the foot that had surgery, while there were 2 amputations and 7 ulcerations (9 different patients) in the contralateral (control) foot. This difference is significant at the p < .002 level.

The results of this study suggest that decompression of the four medial ankle tunnels in the diabetic with symptomatic neuropathy can change the natural history of diabetic neuropathy in terms of ulceration and ampuation.