Touch pressure and sensory density after tarsal tunnel release in diabetic neuropathy

BackgroundLimited quantitative information is available about the improvement of protective sensation after tarsal tunnel release in patients with diabetic peripheral neuropathy.MethodsProspective, non-blinded, non-randomized case series of 10 feet in 8 diabetic patients and 24 feet in 22 non-diabetic patients who had tarsal tunnel release. Preoperative and postoperative (average, 8–9 months) anatomic, quantitative sensory testing was done with touch pressure 1-point threshold (Semmes–Weinstein monofilaments) and 2-point discrimination.ResultsThere was marked, significant postoperative improvement of mean touch pressure 1-point threshold, compared with preoperative values, for medial calcaneal, medial plantar, and lateral plantar nerves in both non-diabetic and diabetic patients. There was minimal improvement in 2-point discrimination only for the medial calcaneal nerve in non-diabetic, but not in diabetic, patients.ConclusionsNerve entrapment at the tarsal tunnel is an important component of diabetic peripheral neuropathy. Tarsal tunnel decompression may improve sensory impairment and restore protective sensation.