Comparison of the effects of subcutaneous anterior transposition and in situ decompression on the histologic and electrophysiologic properties of the ulnar nerve: an experimental study in a rabbit model

Angiosomes of the Ulnar Nerve at the Elbow: A Cadaver Trial Using Contrast-Enhanced Ultrasound

Three major arteries supplying the ulnar nerve in the cubital tunnel are commonly known. However, their vascular territories (angiosomes) have not been described yet. Contrast-enhanced ultrasound was used to identify the angiosomes of posterior ulnar recurrent artery, inferior ulnar collateral artery and superior ulnar collateral artery in 20 fresh, non-frozen human body donors. The arteries were cannulated, and physiologic blood flow was simulated. Contrast agent was applied in each vessel in a randomized sequence, and the length of the contrast-enhancing ulnar nerve segment was measured by a radiologist blinded to the sequence. The angiosome of the posterior ulnar recurrent artery overlaps both other angiosomes. It fully covers the cubital tunnel in 63.6% of specimens. In addition, collateral flow via nerve and muscle branches of the arterial anastomotic network around the elbow (rete articulare cubiti) partly maintains the intra-neural blood flow in the absence of a vascular pedicle. The posterior ulnar recurrent artery is the dominant nutrient vessel of the ulnar nerve in the cubital tunnel. A potential watershed zone exists proximal to the Osborne ligament. Knowledge of these angiosomes may advance surgery of the ulnar nerve in the cubital tunnel.

Cubital tunnel syndrome: a surgical modification to in situ decompression to improve results

BACKGROUND

The gold standard for surgical treatment of cubital tunnel syndrome is in situ decompression. However, this procedure does not come without complications. Subluxation of the ulnar nerve and ulnar nerve neuritis from adhesion formation remain 2 potential complications after this procedure. It has been shown in the literature that young, active, male patients are most likely to have these complications postoperatively. We have developed a modification to in situ decompression by developing a fascial turnover flap and using a porcine submucosa extracellular matrix (Axogen) to help reduce both ulnar nerve subluxation and adhesion formation postoperatively.

METHODS

Thirteen patients underwent cubital tunnel surgery by the highlighted technique to prevent postoperative ulnar nerve subluxation and adhesion formation. Patient outcomes including elbow range of motion, functional status, paresthesia, and grip strength were recorded.

RESULTS

Of the 13 patients, 10 had excellent results, 1 had a good result, and 2 required revision with anterior transposition of the nerve. The mean Mayo Elbow Performance Score of the 11 patients not needing revision was 92.7.

CONCLUSION

The described surgical technique provides surgeons with the ability to directly decompress the ulnar nerve while decreasing postoperative complications such as instability and adhesion formation.

Nerve injuries about the elbow in the athlete

The athlete's elbow is a remarkable example of motion, strength, and durability. The stress placed on the elbow during sport, including the throwing motion, may lead to soft-tissue ligamentous and nerve injury. The thrower's elbow illustrates one example of possible nerve injury about the elbow in sport, related to chronic repetitive tensile and compressive stresses to the ulnar nerve associated with elbow flexion and valgus position. Besides the throwing athlete, nerve injury from high-energy direct-impact forces may also damage nerves around the elbow in contact sports. Detailed history and physical examination can often make the diagnosis of most upper extremity neuropathies. The clinician must be aware of the possibility of isolated or combined nerve injury as far proximal as the cervical nerve roots, through the brachial plexus, to the peripheral nerve terminal branches. Electrodiagnostic studies are occasionally beneficial for diagnosis with certain nerves. Nonoperative management is often successful in most elbow and upper extremity neuropathies. If conservative treatment fails, then surgical treatment should address all potentially offending structures. In the presence of medial laxity and concurrent ulnar neuritis, the medial ulnar collateral ligament warrants surgical treatment, in addition to transposition of the ulnar nerve. The morbidity of open surgical decompression of nerves in and around the elbow is potentially career threatening in the throwing athlete. This mandates an assessment of the adequacy of the nonsurgical treatment and a thorough preoperative discussion of the risks and benefits of surgery.

[Cubital tunnel syndrome: a retrospective review of 55 subcutaneous transpositions with minimum 3-year follow-up]

The surgical management of the cubital tunnel syndrome has no strict rules to follow. Surgical treatments are various, but none of them has been shown to be superior to the others. This retrospective study presents the clinical results in 73 patients who underwent an anterior subcutaneous transposition of the ulnar nerve, between January 2000 and January 2010, with a minimum 3-year follow-up. Fifty-five patients were assessed with an average follow-up of 65.7 months. McGowan grading system as modified by Goldberg was used to analyse clinical results, preoperatively and at follow-up. The DASH score was used to assess physical function. The average preoperative evolution of symptoms was 16.7 months, and mean period to resolution was 4.7 months. The grade in McGowan grading system as modified by Goldberg significatively improved at follow-up (P=0.0002). Only five patients kept paresthesia. The mean postoperative DASH score was 7.27/100. The satisfaction rate was 96%, and all the patients except one returned back to their occupation. There was neither infection nor complex regional pain syndrome. The anterior subcutaneous transposition leads to very good clinical results, satisfaction and physical function. It is an effective surgical method, without complication in our study, which gives long-term results.