Surgical Nerve Decompression for the Treatment of Painful Diabetic Neuropathy of the Foot: A Level 1 Pragmatic Randomized Controlled Trial

SLR - October 2018 - Ryan Bangart

Reference: Best TJ, Best CA, Best AA, Fera LA. Surgical Nerve Decompression for the Treatment of Painful Diabetic Neuropathy of the Foot: A Level 1 Pragmatic Randomized Controlled Trial. Diabetes Res Clin Pract. 2018 Aug 3. pii: S0168-8227(18)30041-X.

Scientific Literature Review

Reviewed By: Ryan Bangart, DPM
Residency Program: Maricopa Medical Center, Phoenix, AZ

Podiatric Relevance: Does surgical decompression of peripheral nerves improve symptoms of diabetic peripheral neuropathy? In those for whom conservative methods have failed, is surgical decompression an option with positive, consistent results? As foot and ankle surgeons, these are questions we may be asking ourselves when treating diabetic peripheral neuropathy, especially when conservative treatment fails.

Methods:
12 patients in study group, 10 in control group.  
Inclusion Criteria: Participants with >5 points on 10-point McGill Pain Questionnaire, total neuropathy score >2, A1C of <8.0 percent. NCV/EMG confirmed peripheral neuropathy in both groups.  
Excluded Criteria: Nondiabetic sources of neuropathy, ankle edema, venous stasis, morbid obesity and vulnerable populations.  

Surgical group underwent decompression of common peroneal, tibial and deep peroneal nerves. Control group with conservative care by PCP. Follow-up visits at three, six and 12 months using McGill Pain Questionnaire, NeuroQol score, total neuropathy score, two-point discrimination, one- and two-point static pressure threshold tests. Primary outcome measures were change in McGill Pain Questionnaire and by NeuroQol pain score. Secondary measurements included improvement in total neuropathy score, NeuroQol quality of life score, improvement in tactile sensation and change in NCV at study end.

Results: Surgical group showed great improvement in primary and secondary outcome measures over control group at the three-month and six-month follow-up. However, 12 months after surgery, primary and secondary outcome measures listed above were not shown to be statistically significant. Despite the data, the intervention group was three times more likely to rate their pain as “better” compared to unchanged or worse.

Conclusions: As the rate of diabetes in population increases, so too will resulting peripheral neuropathy. Common visits to podiatry include the complaint of burning or tingling feet. This can affect patient’s sleep, exercise and quality of life. Patients are often frustrated by the lack of functional treatments that decrease or resolve pain. Data from this article showed that patients showed improvement from surgical nerve release for the first six months. It is unclear as to why the results diminished over time. Perhaps future studies to look at the effectiveness of combining peripheral nerve decompression with adjunctive therapies, such as nutraceuticals or amniotic membrane modalities, would provide longer lasting improvement. Further secondary outcomes with longer results could look at associated reduction in diabetic ulcers or amputations. The authors state that a limitation of the study was the inability to truly measure neuropathic pain, as this is a primarily subjective pain. Development of a new method of quantifying neuropathic pain would lead to results that are more reliable in data analysis.