Electrodiagnostic evidence of nerve regeneration in patients with diabetic Charcot foot treated with proximal tibial cortex transverse distraction.

Objectives: The aim of this study was to investigate whether proximal tibial cortex transverse distraction (PTCTD) could result in nerve regeneration in diabetic Charcot foot via electromyography (EMG).

Patients and methods: Between March 2015 and June 2021, a total of six patients (4 males, 2 females; mean age: 58.8±15.5 years; range, 32 to 75 years) with diabetic Charcot foot treated with PTCTD were retrospectively analyzed. Electromyography was performed preoperatively and six months postoperatively to evaluate nerve regeneration. Healing time, wound area and limb salvage rates were also recorded.

Results: The mean time to wound healing in all patients was 155.17±19.13 (range, 135 to 189) days. The mean wound area was 4.44±2.58 (range, 2.52 to 9.52) cm². No cases of low limb amputation occurred, with a limb salvage rate of 100%. The EMG revealed spontaneous potentials and decreased recruitment in all patients preoperatively. Motor unit potentials were found only in some of the tested muscles. At the final follow-up, the extensor digitorum brevis in four patients (67.7%) had a simple recruitment phase. Three patients (50%) and four patients (67.7%) had increased compound muscle action potential (CMAP) amplitudes in muscles innervated by the nervus peroneus communis and tibial nerve, respectively. In one patient (16.7%), the CMAP was found only at the peroneal head segment of the nervus peroneus communis, but not at the distal end.

Conclusion: Our results indicate that nerve regeneration can be confirmed by EMG after PTCTD in patients with diabetic Charcot foot. However, further multi-center, large-scale, long-term prospective studies are needed to draw more reliable conclusions on this subject.