Journal of Pain Research (Jan 2022)
Experimental Rat Model of Bony Defects in the Facet Joint Maintained with Bone Wax for the Study of Spinal Pain
Abstract
Jinyoung Oh,1,* Daehyun Jo,2,* Kicheol Park,3 Posoon Kang,4 Youngsup Shin5 1Department of Anesthesiology and Pain Medicine, Kyungpook National University Chilgok Hospital, School of Medicine, Kyungpook National University, Daegu, Republic of Korea; 2Jodaehyun Pain Center, Jeonju, Republic of Korea; 3Clinical Research Institute, Daejeon St. Mary’s Hospital, The Catholic University of Korea, Daejeon, Republic of Korea; 4Department of Anesthesiology and Pain Medicine, Konynang University Hospital, Daejeon, Republic of Korea; 5Department of Anesthesiology and Pain Medicine, Chungnam National University College of Medicine, Daejeon, Republic of Korea*These authors contributed equally to this workCorrespondence: Youngsup ShinDepartment of Anesthesiology and Pain Medicine, Chungnam National University College of Medicine, 282, Munhwa-ro, Junggu, Daejon, 35015, Republic of Korea, Tel +82-42-280-7840, Fax +82-42-280-7968, Email [email protected]: Studies using experimental rat models for low back pain due to facet-joint defects are scarce. This study used a novel experimental rat model to determine whether bony defects induced by facetectomy could be maintained by bone wax, thus mimicking spondylolysis, and to analyze the effect of the facetectomy on rat behavior.Patients and Methods: Twelve 10-week-old male Wistar rats weighing 300– 350 g were divided into group A (n = 6) that underwent unilateral facetectomy of the right L5-6 facet joint and group B (n = 6) that additionally applied water-soluble bone wax at the facetectomy site. The difference in the left and right stride length, detected by the footprint test, and change in the left and right facet joint area were compared before and 4 weeks after the experiment.Results: Even though the difference between the left and right stride lengths of groups A and B was not statistically significant, in contrast to group A, group B showed a shorter stride length on the right side (p = 0.22 and 0.46, in group A and group B, respectively). The right facet joint area, where the facetectomy was performed, was significantly smaller in group B 4 weeks after surgery, but not in group A (p = 0.50 and < 0.01, in group A and group B, respectively).Conclusion: Based on the results, we concluded that the bony defects, induced by facetectomy at the L5-6 facet joint, were maintained with bone wax. This study will provide an experimental model for bony defects in the facet joint.Keywords: facet-joint defect, bone wax, Masson’s trichrome stain, footprint test, spondylolysis, rat
