The V-sling: a modified medial intermuscular septal sling for anterior transposition of the ulnar nerve

Subcutaneous Anterior Transposition With Modified Procedures to Prevent Recurrence Associated With the Transposed Ulnar Nerve

Subcutaneous anterior transposition of the ulnar nerve is a common surgical treatment for cubital tunnel syndrome. However, there are surgical failures associated with the new compressive sites at the edge of flexor carpi ulnaris (FCU) and resubluxation posterior to the medial epicondyle of the transposed nerve. To reduce the muscle volume at the edge of FCU, we approach the ulnar nerve by dividing the muscle belly of the FCU humeral heads. This procedure can reduce repeated traction forces on the transposed nerve at the edge of the FCU. To keep the transposed ulnar nerve anteriorly, we use a fat flap including the membranous superficial fascia. This flap can softly stabilize the ulnar nerve and act as a pliable cover to prevent perineural scarring or further constriction around the flap. Ninety-three elbows in 90 patients who had undergone this procedure for cubital tunnel syndrome were evaluated. According to Messina's criteria, the numbers of patients showing excellent, good, fair, and poor recovery were 41 (44%), 47 (51%), 5 (5%), and 0 (0%), respectively. Most patients experience resolution of symptoms and good functional outcomes. None of the patients suffered recurrence, infection, or nerve injury.

Anterior transposition and positioning via helix sling method in cubital tunnel syndrome: An open-label, retrospective trial of maximum 5-year follow-up

Background

Ulnar nerve transposition is used for cubital tunnel syndrome (CuTS) with nerve instability. The aim is to report a modified technique for ulnar nerve transposition using medial intermuscular septum and Osborne's ligament as a double-strand helix sling to recreate a sliding channel for the ulnar nerve and the functional outcomes at follow-ups.

Methods

Twenty-five patients with persistent CuTS underwent nerve release and subcutaneous transposition from January 2017 to January 2022 in our institute. Among them, 9 patients were excluded due to incomplete medical records, lack of follow-up history, or bilateral limb numbness. The medial intermuscular septum with one end attached was excised to rebuild a tension-free double-strand helix sling by anchoring at the residue of Osborne's ligament. The modified Mc-Gowan classification was applied to evaluate the disease severity preoperatively. The quick disability of arm and shoulder and hand (quickDASH) questionnaire and visual analogue scale (VAS) scores were used to evaluate pre- and postoperative symptoms. Ultrasound imaging was utilized for nerve structure evaluation before surgery and at follow-ups.

Results

Sixteen out of twenty-five patients received follow-ups postoperatively (ranging from 9 to 69 months, 36 months in average). No findings indicated subluxation of ulnar nerve or recompression by ultrasound imaging examination. According to quickDASH and VAS scores and physical examination, 14 out of 16 patients showed postoperative improvement in symptoms and function at final follow-ups.

Interpretation

In this modified technique, the medial intermuscular septum and Osborne's ligament can create tension-free helix sling for stable and smooth sliding and preventing subluxation after nerve transposition, which is highly effective and safe for CuTS treatment.

Imaging of the post-operative medial elbow in the overhead thrower: common and abnormal findings after ulnar collateral ligament reconstruction and ulnar nerve transposition

Ulnar collateral ligament (UCL) reconstruction is now being performed more commonly and on younger patients than in prior decades. As a result, radiologists will increasingly be asked to evaluate elbow imaging of patients presenting with pain who have had UCL reconstruction. It is essential for radiologists to understand the normal and abnormal imaging appearances after UCL reconstruction and ulnar nerve transposition, which is also commonly performed in overhead-throwing athletes. Doing so will allow radiologists to provide accurate interpretations that appropriately guide patient management.

Treatment of the ulnar nerve for overhead throwing athletes undergoing ulnar collateral ligament reconstruction

Ulnar nerve (UN) injuries are a common complaint amongst overhead athletes. The UN is strained during periods of extreme valgus stress at the elbow, especially in the late-cocking and early acceleration phases of throwing. Although early ulnar collateral ligament (UCL) reconstruction techniques frequently included routine submuscular UN transposition, this is becoming less common with more modern techniques. We review the recent literature on the sites of UN compression, techniques to evaluate the UN nerve, and treatment of UN pathology in the overhead athlete. We also discuss our preferred techniques for selective decompression and anterior transposition of the UN when indicated. More recent studies support the use of UN transpositions only when there are specific preoperative symptoms. Athletes with isolated ulnar neuropathy are increasingly being treated with subcutaneous anterior transposition of the nerve rather than submuscular transposition. When ulnar neuropathy occurs with UCL insufficiency, adoption of the muscle-splitting approach for UCL reconstructions, as well as using a subcutaneous UN transposition have led to fewer postoperative complications and improved outcomes. Prudent handling of the UN in addition to appropriate surgical technique can lead to a high percentage of athletes who return to competitive sports following surgery for ulnar neuropathy.

Use of a pedicled adipose flap as a sling for anterior subcutaneous transposition of the ulnar nerve

In patients with primary cubital tunnel syndrome, we hypothesize that using a vascularized adipose sling to secure the ulnar nerve during anterior subcutaneous transposition will lead to improved patient outcomes. The adipose flap is designed to surround the ulnar nerve with a pliable, vascularized fat envelope, mimicking the natural fatty environment of peripheral nerves. This technique may offer advantages in securing the anteriorly transposed ulnar nerve and reducing instances of postoperative perineural scarring. Patients experience good functional outcomes; most experience resolution of symptoms.

Submuscular versus subcutaneous anterior ulnar nerve transposition: a rat histologic study

PURPOSE

The 2 most common methods of ulnar nerve anterior transposition are submuscular and subcutaneous. Controversy exists as to which technique yields superior results. The purpose of this study was to examine the histologic differences between the 2 methods in a rat model.

METHODS

Twenty forelimbs in 10 adult Sprague-Dawley rats had bilateral ulnar nerve transpositions; one side with the submuscular method, and the other side with the subcutaneous method. Animals were killed 6 weeks after the index surgery and the forelimbs were examined for histologic evidence of the health of the axons and perineural scar formation.

RESULTS

Nerve health was assessed using a 4-part classification in which 4 = normal nerve, 3 = abnormal axons in one-third cross-sectional area (CSA), 2 = abnormal axons in two-thirds CSA, and 1 = abnormal axons in 100% CSA. Perineural scar formation was assessed using a 3-part classification in which 3 = scar completely encasing nerve, 2 = scar formation partially surrounding nerve, and 1 = no scar. The submuscular method displayed healthier ulnar nerve axons. In addition, the submuscular method displayed less perineural scar tissue.

CONCLUSIONS

On this basis of this rat model, the submuscular method of ulnar nerve anterior transposition displayed histologically healthier axons and less perineural scar tissue when compared to the subcutaneous method.