Revisited HyperSelective Neurectomy in upper limb spasticity

Mathilde Gras, Caroline Leclercq - FESSH (Congrès Européen de Chirurgie de la Main)

Copenhague, Danemark

Juin 2018

Objective: Spasticity is characterized by hyperexcitability of the muscle. Several surgical procedures have been described in order to decrease the muscle tone. Since the description of neurotomy by Stoffel in 1912 for the upper limb, this technique has been criticized, especially because of early recurrences. Our encouraging clinical results of hyperselective neurectomy have led us to review the relevant literature and confront it to the results of our recent anatomical studies. In light of those results we propose guidelines for Hyperselective Neurectomies (NHS).

Methods: A Pubmed search using the terms “spasticity” and: “neurotomy”, “hyponeurotisation”, “hyponeurotization” or “neurectomy” was performed. A total of 130 articles were identified. The inclusion criteria were: English and French literature, detailed description of the technique of neurotomy (including length of incision, method of nerve identification, site of neurotomy, amount of section or resection, method of evaluation of the results), and application of the procedure to the upper limb. We performed an anatomical study of the motor branches of the main flexor, adductor and pronator muscles of the upper limb (except for the shoulder), based on 56 cadaver dissections (musculo-cutaneous nerve: 16, median: 20, ulnar: 20) and confronted these results to the different techniques reported in the literature.

Results: A total of 14 studies met the inclusion criteria, representing 425 cases of neurotomy. All authors performed peroperative nerve stimulation. Most of them performed a partial neurectomy (5 to 10 mm in length, and resection of 50 to 80 % of motor fascicles) rather than a neurotomy. All studies report clinical improvement, with decrease of spasticity, after a 26 months follow-up. However the majority of series (9/14 + 5 unknown) involved mainly nonfunctional hands (65 to 100% of the cases), and all were performed in case of failure of all other treatments. Their results were difficult to analyze because of the many different associated surgical procedures and the lack of objective criteria for evaluating spasticity. Our recent cadaver studies have demonstrated the complexity and the great variability of the oral presentation 2017-11-30 22:18:17 GRAS Mathilde A-0821 anatomy of motor branches; the two most striking features were the very distal location of some motor branches along their target muscle in our dissections, which were most likely missed at surgery in some of the reported series, given the length of some of the incisions; and the frequency of multiples motor branches to several muscles with a common origin, which suggest to perform the neurectomy as distally as possible rather than proximally at, or close to the nerve trunk.

Conclusions: Previous articles have reported clinical improvement after neurectomy performed mainly for nonfunctional hands after failure of other treatments. We hypothesize that the results could be improved by treating all motor branches to each muscle, and by performing the partial neurectomy at the point of entry of each motor branch into the target muscle. Following these new guidelines, an ongoing prospective study shows satisfactory and stable midterm results on spasticity and function.