Outcomes of cooled radiofrequency ablation of cervical nerves for the treatment of chronic pain.

BACKGROUND: Chronic pain, defined as pain persisting for more than 3-6 months, has a mean one-year prevalence in the United States of 25.8% and is one of the most frequent reasons adults seek medical care. Treatment options include physical therapy, analgesics, anticonvulsants, exercise, and muscle relaxants. Even with conventional treatment modalities, in a subset of patients, pain may persist. Cooled radiofrequency ablation (c-RFA), a minimally invasive therapy, employs thermal energy generated by electrical currents to disrupt the transmission of pain stimuli along nociceptive pathways. This leads to an attenuation of pain impulses, primarily through nerve tissue necrosis. The potential of c-RFA to alleviate chronic pain for patients who struggle to find relief elsewhere accentuates the importance of rigorously investigating its outcomes. This study investigates whether patients receiving c-RFA for relief of chronic neck pain caused by cervical facet joint arthropathy experience a reduction in pain scores, the length of this reduction in pain scores, and the magnitude of this reduction in pain. METHODS: This study was a retrospective analysis of data extracted from UW-Health Electronic Medical Health records (EMR), encompassing cervical c-RFA procedures performed from 2015 through 2022. Patient data were obtained, including diagnosis, pre-operative pain score, post-operative pain score, duration of relief, patient age, sex, and BMI. A two-tailed paired t-test was used to statistically analyze the pre-operative and post-operative pain scores, in which a p-value ≤0.05 was considered significant. RESULTS: A total of 450 cervical c-RFA procedures were reviewed, 152 were excluded due to absent pre- or post-op pain scores. 298 were included in the analysis, comprising 203 unique patients: 129 females and 74 males with an average age of 56.03 ± 12.76 and a BMI of 28.76 ± 6.05. Improvement of pain symptoms was reported in 85.23% (n = 263), 6% (n = 19) reported complete pain remission, 8.72% (n = 26) reported no change, and 3.02% (n = 9) reported worsening symptoms. Patients reported an average pre-operative pain score of 6.15 (M = 6.15, SD = 1.55) and an average post-operative pain score of 3.64 (M = 3.64, SD = 2.09) this achieved significance (p < 0.0001). Of the 85.23% (n = 263) charts that noted improvement, there is an average of 48.04% ± 26.53 reduction from their pre-operative pain scores. The average duration of relief lasted 6.67 ± 4.84 months. CONCLUSION: This study supports the potential efficacy of c-RFA as a minimally invasive treatment for chronic neck pain secondary to cervical facet joint arthropathy refractory to conventional treatment measures, demonstrating significant relief for a substantial length of time. Due to chronic pain's detrimental effect on one's quality of life, finding effective treatment options is essential, especially for those refractory to conventional treatments.

Comparison of nylon, vicryl, and fibrin glue for nerve grafting in rats.

OBJECTIVES: For nerve injuries, not amendable to tensionless epineural coaptation of the nerve, autografts are the preferred treatment. Although absorbable sutures are not recommended for nerve repair, there is no evidence that non-absorbable sutures are superior to absorbable sutures. This study aims to assess the effectiveness of non-absorbable monofilament nylon sutures, absorbable monofilament vicryl sutures, and fibrin glue when used for nerve grafting. METHODS: Lewis rats (N = 32) were subjected to a sciatic nerve transection and randomly assigned to a group: graft with Nylon, graft with Vicryl, graft with Fibrin Glue, or no graft. Motor function, sensory function, and thermal pain were assessed during a 12-week recovery period, and immunohistochemistry was used to assess macrophage response. RESULTS: At 12 weeks, the Vicryl and Nylon groups had significantly larger ankle angles at to lift off, which is a measure of motor function, compared to injured controls (p < 0.05). Grafted rats displayed no difference in thermal response but hypersensitivity to mechanical stimuli compared to the uninjured hindlimb. The Nylon, Vicryl, and Fibrin Glue groups all had significantly less atrophy of the gastrocnemius muscle compared to injured controls (p < 0.0001). In the Fibrin Glue group, 3/9 grafts did not incorporate. The Nylon group had significantly less (p = 0.0004) axon growth surrounding the suture holes compared to the Vicryl group. There were no differences in the axon counts, motor neurons, or sensory neurons between all grafted rats. CONCLUSIONS: These results demonstrate that vicryl sutures work just as well as nylon for nerve recovery after injury and grafting.

Gait analysis in swine, sheep, and goats after neurologic injury: a literature review.

Medical research on neurologic ailments requires representative animal models to validate treatments before they are translated to human clinical trials. Rodents are the predominant animal model used in neurological research despite limited anatomic and physiologic similarities to humans. As a result, functional testing designed to assess locomotor recovery after neurologic impairment is well established in rodent models. Comparatively, larger, more clinically relevant models have not been as well studied. To achieve similar locomotor testing standardization in larger animals, the models must be accessible to a wide array of researchers. Non-human primates are the most relevant animal model for translational research, however ethical and financial barriers limit their accessibility. This review focuses on swine, sheep, and goats as large animal alternatives for transitional studies between rodents and non-human primates. The objective of this review is to compare motor testing and data collection methods used in swine, sheep, and goats to encourage testing standardization in these larger animal models. The PubMed database was analyzed by searching combinations of swine, sheep, and goats, neurologic injuries, and functional assessments. Findings were categorized by animal model, data collection method, and assessment design. Swine and sheep were used in the majority of the studies, while only two studies were found using goats. The functional assessments included open pen analysis, treadmill walking, and guided free walking. Data collection methods included subjective behavioral rating scales and objective tools such as pressure-sensitive mats and image-based analysis software. Overall, swine and sheep were well-suited for a variety of assessment designs, with treadmill walking and guided free walking offering the most consistency across multiple trials. Data collection methods varied, but image-based gait analysis software provided the most robust analysis. Future studies should be conducted to standardize functional testing methods after neurologic impairment in large animals.