Porcine submucosal extracellular matrix wrapping of the ulnar nerve in revision cubital tunnel surgery

The wrapping technique aims to protect the nerve when the nerve bed is compromised or more commonly to prevent the recurrence of scar tethering following neurolysis. A wrap provides a physical barrier to scar and helps restore the paraneurial gliding layer. This study aimed to evaluate the results of the AxoGuard® nerve protector, a porcine-derived submucosal extracellular matrix (PECM), used as an adjunct in persistent or recurrent cubital tunnel syndrome (CuTS). This retrospective cohort study evaluated patients diagnosed, between 2012 and 2020, with neuropathic pain who underwent revision surgery. Patients were categorised into Group A (revision surgery only) and Group B (revision surgery and adjunctive PECM nerve wrapping). Disease severity was scored at the baseline and six months post-operatively using the McGowan classification. A linear regression model was used to assess the effect of wrapping the ulnar nerve on the clinical outcome at six months. Fifty-nine nerves were treated; among them, adjunctive PECM wrapping was used in 32 nerves. Disease severity at baseline was similar between the groups. After adjusting for differences in baseline characteristics, participants in Group B improved with a significant difference of 0.43 McGowan points over Group A (95% CI (0.01-0.86), p = 0.049). There were no implant-related complications. Group B improved with excellent or good outcomes in 84.4% patients at the final follow-up. Persistent or recurrent CuTS were associated with neuropathic pain and significant nerve scar tether. The use of PECM appears to lead to improved clinical symptoms, possibly by reducing adhesions and encouraging physiological glide. LEVEL OF EVIDENCE: Level III evidence.