Tibial Nerve Repair in a Dog Model: Effect of Local and Systemic Administration of Erythropoietin.

Purpose: This study aimed to assess the effectiveness of erythropoietin (EPO) as a novel treatment for peripheral nerve injury after surgical repair of an induced tibial nerve injury in dogs.

Methods: Mongrel dogs (n = 27) were randomly divided into three equal groups. A complete tibial nerve injury was induced and repaired directly by stay sutures and the local application of 1 mL fibrin glue (control group). In the "systemic" group, 20,000 IU of EPO were given subcutaneously immediately after surgery and on the first and second days after surgery. In the "local" group, EPO was mixed with fibrin glue at 1,000 IU/mL. Lameness score, compound muscle action potential of the tibial nerve, and serum biochemical and histopathological examinations were performed to evaluate the treated dogs over the study period (12 weeks).

Results: EPO significantly improved the lameness score and compound muscle action potential in both the systemic and local groups. After 12 weeks, systemic and local groups showed earlier improvement in lameness, reaching scores of -1 and 0, respectively, in comparison with the control group, which did not reach a score of -1. The histological study revealed a normal architecture of the nerve bundles within connective tissue. The axons were aligned in a regular pattern, whereas the control group had disrupted and degenerated nerve axons with large gaps in between.

Conclusions: EPO has an accelerating healing effect after tibial nerve surgical repair. Local EPO mimics systemic EPO treatment without systemic adverse effects. These findings indicated that EPO has a potential role in tibial nerve recovery and nerve regeneration.

Clinical Relevance: The findings of the present experimental study supported the beneficial effects of systemic and local EPO when combined with peripheral nerve surgical repair, potentially improving functional outcomes and enhancing faster recovery.