Retrospective multicenter case-controlled study.
The objective of this study was to quantitatively examine imaging findings of idiopathic spinal cord herniation (ISCH) and determine the relationship between the image findings and the severity of pre- and postoperative neurological symptoms.
Many radiographic types of ISCH have been identified with regard to the location of the hernial opening or amount of herniated spinal cord. However, few previous studies have investigated the relationship between radiographic findings and the severity of neurological symptoms.
Of 30,469 patients who underwent spinal surgery at 7 hospitals, 18 patients who underwent surgery for ISCH were identified. Their preoperative neurological severity, disease duration, magnetic resonance imaging findings, computed tomography myelography findings, surgical findings, and postoperative improvements were retrospectively examined. The spinal cord kink angle and minimum cord occupancy rate within the dural tube were measured. In addition, herniation was classified according to the location of the hiatus as either central (type C) or lateral (type L) type.
A negative correlation was found between the spinal cord kink angle and the minimum cord occupancy rate. Patient age was significantly higher in the severe paralysis group than in the mild paralysis group. In addition, the number of patients with type C herniation and the kink angle were significantly higher in the severe paralysis group. The number of patients with type L herniation was higher in the significant recovery group than in the mild recovery group; however, the difference was not significant.
Patients with a large spinal cord kink angle had a smaller spinal cord occupancy rate within the dural tube, and this resulted in severe preoperative conditions. Type C ISCH cases had a severe preoperative neurological deficit and poor postoperative neurological recovery, and the spinal cord in such cases might be damaged irreversibly.
Level of Evidence: 4
∗Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
†Department of Orthopedic Surgery, Konan Kosei Hospital, Aichi, Japan
‡Department of Orthopedic Surgery, Chubu Rosai Hospital, Nagoya, Japan
§Department of Orthopedic Surgery, Nagoya Daini Red Cross Hospital, Nagoya, Japan
¶Department of Orthopedic Surgery, Aichi Medical University, Aichi, Japan
||Department of Orthopedic Surgery, Toyohashi Municipal Hospital, Aichi, Japan
∗∗Department of Orthopedic Surgery, Hamamatsu Medical University, Shizuoka, Japan.
Address correspondence and reprint requests to Shiro Imagama, MD, PhD, Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan, 65 Tsurumai, Showa-ku, Nagoya, Aichi 466-8560, Japan; E-mail: firstname.lastname@example.org
Received 25 August, 2017
Accepted 16 October, 2017
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work.
Relevant financial activities outside the submitted work: consultancy.