Objective: Traumatic amputations and postamputation pain are common. Various surgical techniques have been explored to prevent and treat neuromas. Despite multiple methods for management of the nerve stumps in amputations, there is no operative gold standard. A new technique, regenerative peripheral nerve interface (RPNI), has been described with excellent early outcomes. This technique uses a muscle or skin graft for treatment of, or prophylaxis against, neuroma development. There have been no randomized, controlled trials demonstrating the superiority of RPNI compared to traditional surgical techniques. We hypothesize the RPNI construct will be superior in preventing neuroma development, neuroma tenderness, and hyperalgesia than the control or traditional methods. Methods: We employed a rat model of nerve amputation. One of three treatment groups were randomly assigned to each rat hindlimb: a positive control group in which the nerve was transected and sewn directly into the overlying skin, a traditional group where the nerve was transected and implanted into the biceps femoris muscle, and the experimental group where a muscle RPNI construct was created. Behavioral analysis was performed assessing mechanical hyperalgesia, tactile hyperalgesia, and neuroma tenderness on a weekly basis. After eight weeks of recovery, the rats were euthanized and the nerve sent for histologic analysis. Statistical analysis was done with 2-way repeated measures ANOVA and a logistic regression with MedCalc software. Results: There were no statistically significant differences in any of the treatment groups in mechanical hyperalgesia, tactile hyperalgesia, neuroma tenderness, or weight change. There were significant changes in these metrics over the course of the study, but no difference in these changes between the treatment groups. Excised transected nerve and nerve targets from the experimental animals showed minimal differences in neuroma formation. Each RPNI remained viable and vascularized. Conclusion: This study did not demonstrate any significant differences between the treatment groups. Burying a transected peripheral nerve into muscle as well as wrapping the nerve with an RPNI construct are both suitable options for prevention of neuroma development. The behavioral analysis did not show any significant differences between the positive control group and the experimental groups. This may be explained by the panniculus carnosus, a dermal muscular layer found in rats. It is a distinct muscular layer that could explain why the rate of neuroma formation in the positive control group did not have 100% permeance, as originally hypothesized. This layer may have acted as a second implantation into muscle group, rather than a positive control. Additionally, an eight-week recovery period may have been insufficient to detect behavioral differences amongst the groups. Further research should be done to analyze systemic inflammatory changes as well as analyze how different constructs could be used to wrap around a nerve stump without causing additional donor site morbidity. Corresponding author: Elizabeth Lucich, [email protected]