Effect of sagittal plane deformity of the lumbar spine on epidural fibrosis formation after laminectomy: an experimental study in the rat.
METHODS
An animal model of postlaminectomy lumbar column sagittal plane deformity was designed in rats.


OBJECTIVE
To analyze the effect of lumbar column deformity (lordosis and kyphosis) on postlaminectomy epidural fibrosis formation.


BACKGROUND
Incidence of peridural fibrosis formation after lumbar spinal surgery is considerably high. Instability and sagittal plane deformity of the lumbar spine has been implicated (not proven) as the factors for the development of epidural fibrosis. The effect of traction (kyphosis) or relaxation (lordosis) of the lumbar spine on epidural fibrosis formation is not known.


METHODS
L4 laminectomies were performed in 30 rats. Three equal groups were formed. In the control group (group I), only laminectomy was performed. In other groups after laminectomy, lumbar lordosis (group II) and kyphosis (group III) was maintained with steel implants. The scar formation was evaluated both histologically and histomorphometrically on the 12th postoperative week.


RESULTS
Kyphosis developed in group I. The mean amount of peridural scar tissue was significantly more evident in groups I and III than the lordosis group. The extent of adherence to the dura mater and the nerve roots was most apparent in group III.


CONCLUSIONS
Kyphosis and consequent traction of the lumbar spine is one of the causes for increased epidural fibrosis formation after laminectomy. On the contrary, establishment of lordosis and relaxation of the lumbar spine decreased the scar tissue formation in rats.
Department of Orthopaedic Surgery, Pendik Sifa Hospital, Istanbul, Turkey.
Cengiz
C
Cabukoglu
Osman
O
Güven
Yakup
Y
Yildirim
Hasan
H
Kara
Saime Sezgin
SS
Ramadan
D000818:Animals; D001864:Bone Wires / Q000009:adverse effects; D002921:Cicatrix / Q000473:pathology; D004388:Dura Mater / Q000473:pathology; D004824:Epidural Space / Q000473:pathology; D005260:Female; D005355:Fibrosis; D016268:Internal Fixators; D007738:Kyphosis / Q000209:etiology* / Q000473:pathology; D007796:Laminectomy; D008141:Lordosis / Q000209:etiology* / Q000473:pathology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D011183:Postoperative Complications / Q000209:etiology* / Q000473:pathology; D019736:Prostheses and Implants / Q000009:adverse effects; D011859:Radiography; D051381:Rats; D017207:Rats, Sprague-Dawley; D013126:Spinal Nerve Roots / Q000473:pathology; D013314:Stress, Mechanical; D000267:Tissue Adhesions / Q000473:pathology