Hyperselective neurectomy in the treatment of elbow and wrist spasticity: an anatomical study and incision design

Abstract

Objective

Hyperselective neurectomy is used to treat spastic arm paralysis. The aim of the study was to analyze the nerve branching patterns of elbow and wrist flexors/pronator to inform hyperselective neurectomy approached.

Methods

Eighteen upper extremities of fresh cadaver specimen were dissected. The number of motor branches from the musculocutaneous nerve to biceps brachii and brachialis, median nerve to pronator teres, flexor carpi radialis and ulnar nerve to flexor carpi ulnaris were counted. The origin site of each primary motor branch was documented.

Results

Either biceps or brachialis was innervated by one or two primary motor branches. Pronator teres was innervated by one to three motor trunks and the pattern for flexor carpi radialis was a common trunk with other branches. The origin of the biceps and brachialis nerve trunk was located approximately 30% to 60% of the length of the arm. The median nerve branched to pronator teres and flexor carpi radialis at the region about 34mm (SD 18.8mm) above and 50mm (SD 14.9mm) below the medial epicondyle. Flexor carpi ulnaris was innervated by one to three motor trunks and the mean distance from the medial epicondyle to the origin of flexor carpi ulnaris nerve on ulnar nerve was 18.7 mm (SD 6.5mm).

Conclusion

Primary motor branches to elbow flexors, wrist flexors and pronators were various, while the regions of their origins were relatively settled. It was recommended the incisions be designed according to the location of the primary motor trunks.

Keywords:

• Hyperselective neurectomy
• spasticity
• upper extremity
• branching pattern
• incision

Ethical approval

The authors confirm that the principles outlined in the Declaration of Helsinki were followed throughout this study.

Disclosure statement

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by National Natural Science Foundation of China [81801941, 81525009, 81830063]; Shanghai Municipal Clinical Medical Center Project [2017ZZ01006]; Program of Shanghai Municipal Commission of Health and Family Planning [20164Y0018]; Fudan University-SIBET Medical Engineering Joint Fund [YG2017-012].