64 patients with diabetes mellitus and a neuropathic plantar ulcer were randomized to immobilization in a total-contact cast alone or in combination with percutaneous Achilles tendon lengthening to determine the effects on ulcer recurrence. The mean follow-up period was 2.1 years. In the first 7 months of follow-up, significantly more patients in the total-contact group had an ulcer recurrence compared to the Achilles lengthening group. This trend continued through 2 years. All ulcers healed in the Achilles tendon lengthening group, and the risk for ulcer recurrence was 75% less at seven months and 52% less at two years than that in the total-contact cast group.