Abstract:

Background

Cubital tunnel syndrome is one of the most common peripheral nerve entrapment diseases， which is often caused by an inflammatory reaction of repeated friction of the ulnar nerve at the cubital canal， leading to clinical syndrome.In the stage of severe cubital tunnel syndrome， the aseptic inflammatory reaction caused by friction and ischemia of the ulnar nerve leads to the thickening of the epineural membrane and pathological progression such as inter-fascicular scar and fibrotic tissue hyperplasia， which leads to further compression of nerve fiber tissue， formation of permanent scar tissue，and further reduction of local nerve sheath fluid and nerve blood supply.It leads to Waller's degeneration of myelinated nerve fibers， which has serious consequences for the recovery of nerve function.Failure to receive timely treatment will lead to patients' hypoaesthesia， muscle atrophy， and even joint contracture， and surgical intervention can improve clinical effects.At present， releasing local nerves trapped by anatomical structures is one of the surgical methods used to treat elbow tunnel syndrome.There are many discussions on the anterior ulnar nerve release， and various surgical methods have advantages and focus.Some surgical methods have been eliminated due to unsatisfactory efficacy.The protection of accompanying vessels during the anatomic dissociation of the ulnar nerve has not been discussed in detail.However， anatomical studies on accompanying vessels of the ulnar nerve in the elbow have made it clear that the ulnar nerve has three blood vessels supplying to the cubital canal， and the accompanying vessels of the ulnar nerve can move forward together with the ulnar nerve to the ulnar nerve sulci， with no tension in the previa vessels.This study mainly focused on the main blood supply of the ulnar nerve near the cubital canal， including the small branches of the inferior collateral ulnar artery and the recurrent ulnar artery entering the fascia around the ulnar nerve and the outer membrane of the ulnar nerve， and finally reaching the nutrition of the ulnar nerve.With this focus， the ulnar nerve preposition operation with the inferior collateral ulnar artery of the elbow and the fascia around the ulnar nerve was designed to treat severe cubital tunnel syndrome.

Objective

To investigate the operative methods and clinical effects of ulnar nerve preposition with the ulnar inferior collateral artery and the fascia around the ulnar nerve and ulnar nerve preposition with ulnar inferior collateral artery in treating severe cubital tunnel syndrome.

Methods

From October 2022 to September 2024， 30 patients with severe cubital tunnel syndrome admitted to our hospital were randomly divided into two groups， which were divided into the ulnar nerve preposition group with the ulnar inferior collateral artery of the elbow and the peripheral fascia of the ulnar nerve by different surgical methods and the ulnar nerve preposition group with the ulnar inferior collateral artery of the elbow.The elbow joint was fixed at 90-120°flexion by plaster or brace after surgery.The braking time was 3 weeks.Michelin alleviated the nerve edema， and a mecobalamine tablet was used for nerve nutrition.Outcome measures： According to the functional evaluation criteria of the upper limb，the postoperative autonomous sensation of the hand， the muscle strength of the internal muscle of the hand，the discernibility of two points in the abdomen of the little finger， and the electromyography nerve conduction velocity of the elbow were compared between the two groups.

Results

The 30 patients were followed for 6 to 24 months （mean 13.2 months）.The superior rate of ulnar nerve preposition with inferior ulnar artery and fascia around the ulnar nerve （study group） was 86.67%.The excellent and good rate of ulnar nerve preposition with the inferior ulnar artery of the elbow （control group） was 73.33%.There was no significant difference between the two groups in the changes of ulnar nerve conduction velocity， hand autonomic sensation， and two-point discernible sense of the distal finger of the little finger before and after surgery（P＞0.05）.However， the relief rate of postoperative hand numbness， pain， and other symptoms， as well as the surgical satisfaction of patients， significantly increased.

Conclusion

The ulnar nerve preposition with the inferior ulnar artery of the elbow and the fascia around the ulnar nerve can more completely protect the blood supply of the local ulnar nerve of the elbow， which is a reliable surgical treatment for severe cubital tunnel syndrome and obtain better therapeutic effect and patient satisfaction.

Key words: Severe cubital tunnel syndrome, Ulnar collateral artery, Ulnar nerve anterior surgery, Ulnar nerve fascia around the elbow