Recurrence of ulnar tunnel syndrome: Long-term clinical and functional results of surgical management using revision neurolysis and subcutaneous anterior transposition

Revision surgery for recurrent ulnar nerve compression following failed subcutaneous transposition

BACKGROUND

Recurrent ulnar nerve compression after primary anterior subcutaneous transposition is relatively rare, and revision surgery is challenging. This study retrospectively evaluated the clinical outcomes of revision anterior subcutaneous transposition for recurrent ulnar nerve compression.

METHODS

Eight patients who underwent revision anterior subcutaneous transposition for recurrent ulnar nerve compression were enrolled in this study. The outcomes were based on preoperative and postoperative symptoms, physical examination findings, and electromyographic evaluation.

RESULTS

Ulnar nerve enlargement was preoperatively found in all patients with a mean cross sectional area of 0.15 cm2 (range, 0.14-0.18 cm2). Intraoperative findings showed that recurrent compression occurred in three areas, including the medial intermuscular septum (n = 5), the medial epicondyle (n = 6) and nerve entrance to forearm fascia (n = 1). Post-operation, significant improvements were observed in ring/little finger numbness (from severe to mild, p = 0.031), grip strength (from 48.00% to 80.38% of the intact side, p < 0.001) and McGowan grade (from Grade III to Grade I, p = 0.049). Postoperative electromyography test also showed significant improvement in motor nerve conduction at elbow (velocity, 23.30 ± 9.598 vs. 35.30 ± 9.367, p = 0.012; amplitude, 3.40 ± 3.703 vs. 5.65 ± 2.056, p = 0.007) and sensory nerve conduction at wrist (velocity, 27.04 ± 22.450 vs. 36.45 ± 18.099, p = 0.139; amplitude, 1.44 ± 1.600 vs. 4.00 ± 2.642, p = 0.011). Seven of the eight patients reported satisfaction with the postoperative results.

CONCLUSIONS

Revision anterior subcutaneous transposition was an effective treatment for recurrent ulnar nerve compression from prior failed procedures.

The Unpredictable Ulnar Nerve-Ulnar Nerve Entrapment from Anatomical, Pathophysiological, and Biopsychosocial Aspects

Peripheral nerves consist of delicate structures, including a rich microvascular system, that protect and nourish axons and associated Schwann cells. Nerves are sensitive to internal and external trauma, such as compression and stretching. Ulnar nerve entrapment, the second most prevalent nerve entrapment disorder after carpal tunnel syndrome, appears frequently at the elbow. Although often idiopathic, known risk factors, including obesity, smoking, diabetes, and vibration exposure, occur. It exists in all adult ages (mean age 40-50 years), but seldom affects individuals in their adolescence or younger. The patient population is heterogeneous with great co-morbidity, including other nerve entrapment disorders. Typical early symptoms are paresthesia and numbness in the ulnar fingers, followed by decreased sensory function and muscle weakness. Pre- and postoperative neuropathic pain is relatively common, independent of other symptom severity, with a risk for serious consequences. A multimodal treatment strategy is necessary. Mild to moderate symptoms are usually treated conservatively, while surgery is an option when conservative treatment fails or in severe cases. The decision to perform surgery might be difficult, and the outcome is unpredictable with the risk of complications. There is no consensus on the choice of surgical method, but simple decompression is relatively effective with a lower complication rate than transposition.