title: Novel biomechanical quantification methodology for lumbar intraforaminal spinal nerve adhesion in a laminectomy and disc injury rat model.
abstract: Spinal nerve fibrosis following injury or surgical intervention may play an important role in the pathophysiology of chronic back pain. In this current study, we demonstrate the role of biomechanical quantification of lumbar intraforaminal spinal nerve adhesion and tethering in the analysis of the post-laminectomy condition and describe a direct methodology to make this measurement. Twenty age-matched Sprague-Dawley male rats were divided into operative and non-operative (control) groups. Operative animals underwent a bilateral L5-L6 laminectomy with right-side L5-6 disc injury, a post-laminectomy pain model previously published by this lab. At eight weeks, animals were sacrificed and the strength of adhesion of the L5 intraforaminal spinal nerve to surrounding structures was quantified using a novel biomechanical methodology. Operative animals were found to have a significantly greater load to displace the intact right L5 spinal nerve through the intervertebral foramen when compared to control animals. The findings show that the post-laminectomy condition creates quantifiable fibrosis of the spinal nerve to surrounding structures and supports the conclusion that this fibrosis may play a role in the post-laminectomy pain syndrome.
authors: Department of Orthopaedic Surgery, Veterans Affairs Medical Center and University of California, San Diego, CA, USA. vkulkarni@ucsd.edu
authors: Vedant A
authors: VA
authors: Kulkarni
authors: Jennifer B
authors: JB
authors: Massie
authors: Florian
authors: F
authors: Zauner
authors: Mark
authors: M
authors: Murphy
authors: Wayne H
authors: WH
authors: Akeson
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000379:methods; D002420:Cauda Equina / Q000293:injuries / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D004388:Dura Mater / Q000473:pathology / Q000503:physiopathology; D005355:Fibrosis / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D005727:Ganglia, Spinal / Q000473:pathology / Q000503:physiopathology; D007403:Intervertebral Disc / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D007405:Intervertebral Disc Displacement / Q000150:complications / Q000503:physiopathology / Q000601:surgery; D007796:Laminectomy / Q000009:adverse effects*; D017116:Low Back Pain / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008954:Models, Biological; D017288:Pain Threshold / Q000502:physiology; D010149:Postoperative Pain / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D011843:Radiculopathy / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013126:Spinal Nerve Roots / Q000293:injuries / Q000473:pathology / Q000503:physiopathology; D013127:Spinal Nerves / Q000293:injuries / Q000473:pathology / Q000503:physiopathology*; D013130:Spinal Stenosis / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D000267:Tissue Adhesions / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*