Image classification of idiopathic spinal cord herniation based on symptom severity and surgical outcome: a multicenter study.
OBJECTIVE
The purpose of this study was to provide the first evidence for image classification of idiopathic spinal cord herniation (ISCH) in a multicenter study.


METHODS
Twelve patients who underwent surgery for ISCH were identified, and preoperative symptoms, severity of paralysis and myelopathy, disease duration, plain radiographs, MR imaging and CT myelography findings, surgical procedure, intraoperative findings, data from spinal cord monitoring, and postoperative recovery were investigated in these patients. Findings on sagittal MR imaging and CT myelography were classified into 3 types: a kink type (Type K), a discontinuous type (Type D), and a protrusion type (Type P). Using axial images, the location of the hiatus was classified as either central (Type C) or lateral (Type L), and the laterality of the herniated spinal cord was classified based on correspondence (same; Type S) or noncorrespondence (opposite; Type O) with the hiatus location. A bone defect at the ISCH site and the laterality of the defect were also noted.


RESULTS
Patients with Type P herniation had a good postoperative recovery, and those with a Type C location had significant severe preoperative lower-extremity paralysis and a significantly poor postoperative recovery. Patients with a bone defect had a significantly severe preoperative myelopathy, but showed no difference in postoperative recovery.


CONCLUSIONS
The authors' results showed that a Type C classification and a bone defect have strong relationships with severity of symptoms and surgical outcome and are important imaging and clinical features for ISCH. These findings may allow surgeons to determine the severity of preoperative symptoms and the probable surgical outcome from imaging.
Imagama
Shiro
S
Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan. imagama@med.nagoya-u.ac.jp
Matsuyama
Yukihiro
Y
Sakai
Yoshihito
Y
Nakamura
Hiroshi
H
Katayama
Yoshito
Y
Ito
Zenya
Z
Wakao
Norimitsu
N
Sato
Koji
K
Kamiya
Mitsuhiro
M
Kato
Fumihiko
F
Yukawa
Yasutsugu
Y
Miura
Yasushi
Y
Yoshihara
Hisatake
H
Suzuki
Kazuhiro
K
Ando
Kei
K
Hirano
Kenichi
K
Tauchi
Ryoji
R
Muramoto
Akio
A
Ishiguro
Naoki
N
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008591:Meningomyelocele / Q000150:complications* / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020886:Somatosensory Disorders / Q000175:diagnosis / Q000209:etiology / Q000628:therapy; D013118:Spinal Cord Diseases / Q000150:complications* / Q000473:pathology* / Q000601:surgery; D013904:Thoracic Vertebrae; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome