It has been demonstrated in four independent reports from 1992 to 2000 that decompression of peripheral nerves in diabetics can restore sensation and relieve pain in patients with symptomatic neuropathy. Two of these studies required patients to have a positive Tinel sign over the tibial nerve in the tarsal tunnel as an indication for surgery, while two of the studies did not. There have been no reports of being able to restore sensation to the feet of patients with neuropathy of unknown etiology.

The purpose of the present study was to evaluate prospectively, beginning in 1997, the results of surgery to decompress the tibial nerve and its branches based upon the presence or absence of a positive Tinel sign at the tarsal tunnel in patients with symptomatic neuropathy due to diabetes of unknown etiology (26). Outcome was determined at a minimum of one year follow-up, ending in January of 2001. Outcome was dichotomized into either good-excellent or failure-poor, permitting analysis for sensitivity and specificity.

For patients with diabetic neuropathy, the presence of a Positive Tinel sign prior to surgery gave a sensitivity of 88%, a specificity of 50% and a positive predictive value of 88% in identifying patients who would have a good to excellent outcome. For patients with neuropathy of unknown etiology, the presence of a Positive Tinel sign prior to surgery gave a sensitivity of 95%, a specificity of 56%, and a positive predictive value of 93% in identifying patients who would have a good to excellent outcome.