Long-Term Patient-Reported Outcomes After Release of the Ulnar Nerve in Guyon's Canal

There are no large studies describing patient-reported outcomes after ulnar tunnel release (UTR). The aims of this study are to describe the causes of ulnar tunnel syndrome (UTS), the incidence of UTR, and identify factors associated with long-term patient-reported outcomes after UTR.

We reviewed the medical charts of 76 adult patients who had an UTR for UTS at 1 of 5 academic medical centers between January 1, 2003 and January 1, 2017. Of these patients, 30 completed a follow-up questionnaire including the PROMIS Upper Extremity (PROMIS-UE), Numerical Rating Scale for Pain Intensity (NRS Pain), the Global Rating Scale of Change, and a custom questionnaire about satisfaction and current UTS-specific symptoms.

Approximately 3% of the patients who underwent a decompression surgery of the ulnar nerve at one of our centers between 2003 and 2017 had a UTR. The most frequent described cause of compression was ganglion cyst (16%). The 30 patients who completed the follow-up survey had a mean ± SD PROMIS-UE score of 46.0 ± 12 and a median (interquartile range) NRS Pain score of 0.5 (0-4). Twenty-five patients (83%) described themselves improved compared to before UTR. Bivariate analysis showed that patients who had a preoperative electromyography and nerve conduction velocity study (EMG/NCV) positive for UTS had a higher mean ± SD PROMIS-UE score compared to patients who had a negative EMG/NCV for UTS, respectively 48 ± 12 versus 37 ± 7.6, P = .04.

Diagnosis of UTS is challenging and made with substantial variation among surgeons. We observed that most patients improve after UTR, but patients with a negative EMG/NCV have a lower PROMIS Upper Extremity score at long-term follow-up.