• Glen Liau Zi Qiang, Sherry Liu Jiani, Wing Moon Raymond Lam, Jiayi Weng, Lucius Ho Kang Hua, Louise Kok, Syeda Fabeha Husain, Ling Liu, Sanjay Khanna, and Hee Kit Wong.
• University Spine Centre, University Orthopaedics, Hand and Reconstructive Microsurgery Cluster, National University Hospital System, Singapore, Singapore.
• Spine. 2023 Sep 15; 48 (18): 132613341326-1334.

Study DesignThis is a basic science, animal research study.ObjectiveThis study aims to explore, in rodent models, the effectiveness of systemic nonsteroidal anti-inflammatory drugs in reducing recombinant human bone morphogenetic protein-2 (rhBMP-2) induced neuroinflammation.Summary Of Background DatarhBMP-2 is increasingly used to augment fusion in lumbar interbody fusion surgeries, although it can cause complications including postoperative radiculitis.Materials And MethodsEighteen 8-week-old Sprague-Dawley rats underwent Hargreaves testing to measure the baseline thermal withdrawal threshold before undergoing surgical intervention. The L5 nerve root was exposed and wrapped with an Absorbable Collagen Sponge containing rhBMP-2. Rats were randomized into 3 groups: (1) Low dose (LD), (2) high dose (HD) diclofenac sodium, and (3) saline, receiving daily injection treatment. Hargreaves testing was performed postoperatively on days 5 and 7. Seroma volumes were measured by aspiration and the nerve root was then harvested for hematoxylin and eosin, immunohistochemistry, Luxol Fast Blue staining, and real-time quantitative polymerase chain reaction. The Student t test was used to evaluate the statistical significance among groups.ResultsThe intervention groups showed reduced seroma volume, and a general reduction of inflammatory markers (MMP12, MAPK6, GFAP, CD68, and IL18) compared with controls, with the reduction in MMP12 being statistically significant ( P = 0.02). Hematoxylin and eosin and immunohistochemistry of the nerve roots showed the highest macrophage density in the saline controls and the lowest in the HD group. Luxol Fast Blue staining showed the greatest extent of demyelination in the LD and saline groups. Lastly, Hargreaves testing, a functional measure of neuroinflammation, of the HD group demonstrated a minimal change in thermal withdrawal latency. In contrast, the thermal withdrawal latency of the LD and saline groups showed a statistically significant decrease of 35.2% and 28.0%, respectively ( P < 0.05).ConclusionThis is the first proof-of-concept study indicating that diclofenac sodium is effective in alleviating rhBMP-2-induced neuroinflammation. This can potentially impact the clinical management of rhBMP-2-induced radiculitis. It also presents a viable rodent model for evaluating the effectiveness of analgesics in reducing rhBMP-2-induced inflammation.Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.

32 keywords...

hide…