Managing Spondylotic Cervical Myeloradiculopathy Using Oblique Cervical Corpectomy
Authors: Elbadrawi A. Mohamed 
Published: May 2014

Introduction

The technique of oblique cervical corpectomy describes preservation of significant portion of the anterior and lateral aspects of the vertebral body.1 In 1999, Ozer et al described a technique and called it “open window corpectomy” which is designed to remove a minimal amount of bone and achieve satisfactory decompression; with the use of a high-speed drill under surgical microscope, only the dorsal surface of the vertebral body is removed after appropriate microdiscectomies. This leaves the anterior and the lateral portions of the vertebral body intact.2 This corpectomy did not affect the stability of the cervical spine and requires no stabilization procedure. Karalar et al conducted an in vitro biomechanical analysis of cervical multilevel oblique corpectomy in sheep and concluded that the procedure does not result in instability of the spine.3 This technique provides a wide anterolateral decompression of the spinal canal and foramen at single or multiple levels, kyphotic change is not a contraindication as long as vertebral stability is preserved, no need for bone grafting and/or fixation, and excellent exposure through lateral approach which is desirable in cases of recurrence after previous anterior surgery.4

Materials and Methods

The current study was conducted as a randomized prospective study in a series of 38 patients who underwent treatment for cervical myeloradiculopathy by the oblique cervical corpectomy. It was held between January 2005 and February 2008. Inclusion criteria were; clinically evident cervical myeloradiculopathy, CT scan and /or MRI with single or multiple level canal stenosis mainly as anterolateral compression. Dynamic X-rays were done; if any instability or anterolisthesis >2?mm between any two contiguous vertebral bodies, patient is excluded from the study. Patients had to meet at least two of the inclusion criteria. These criteria are similar to inclusion criteria enumerated in a study made by Salvatore et al.4 Patients were presented by myelopathic changes; these changes were evident by clinical findings including upper motor changes, radiologic finding as cord signal changes in MRI and dimensional changes in CT scans. Radiculopathy was present in all patients in the form of radicular sensory, motor or reflexes alteration. Patients were subjected to evaluation by Nurick score to get an overall functional evaluation of the difficulty of ambulation and walking. The severity of myelopathy was graded by functional assessment score proposed by the Japanese Orthopedic Association (JOAS), and the postoperative recovery was evaluated by the formula suggested by Hirabayashi et al: Post-op score − pre-op score ÷ 17 (full score) − pre-op score × 1005 Both local symptoms (pain, stiffness, and axial symptoms) and radicular pain were evaluated using the 10 points Visual Analog Scale (VAS). Radiological evaluation included preoperative and postoperative plain radiographs of the cervical spine anteroposterior (AP), lateral and dynamic views. The canal dimensions are evaluated by MRI and CT scan. After exposure the intervertebral discs above and below the desired vertebral body are partially excised. The part of disc corresponding to the planned corpectomy is removed laterally to the uncinate process and posteriorly till exposing the disc-posterior osteophyte complex. Uncinate process and posterior disc-osteophyte complex were left and removed later after corpectomy is done to develop enough working space for the excision of both structures. Using a high speed drill, oblique corpectomy is done. The vertebral body is drilled in an oblique fashion from the lateral side toward the opposite posterolateral corner (Fig.). The posterior longitudinal ligament must be opened and as much as possible removed to ensure optimal cord decompression.

Results

The mean operative time was 182 ± 23.3 (SD) minutes. Mean intraoperative blood loss was 321.3 ± 102.1(SD) ml. There is a statistically significant improvement in the JOAS; mean JOA score improved from 7.94 ± 2.28 (SD) points preoperatively to 14.38 ±1.62 (SD) points at follow-up ( p < 0.05). The recovery rate was 71.08%. The preoperative incidence of significant axial symptoms was ( n = 3 out of 38 patients) and increased by the end of follow up to 5/38 ( p < 0.05). The mean preoperative VAS for axial symptoms was 2.1± 1.2(SD) while the mean postoperative VAS by the end of follow-up was 2.3 ± 1.1 SD ( p > 0.05). Mean preoperative VAS for radicular symptoms was 7.1 ± 1 SD and improved to mean postoperative VAS of 4.2 ± 1.2 SD ( p < 0.05).

Conclusion

Oblique cervical corpectomy is a valid safe technique for the management of multisegmental cervical spondylosis that permits early patient mobilization with no postoperative instrumentation. Disclosure of Interest None declared References Wada E, Suzuki S, Kanazawa A, Matsuoka T, Miyamoto S, Yonenobu K. Subtotal corpectomy versus laminoplasty for multilevel cervical spondylotic myelopathy: a long-term follow-up study over 10 years. Spine 2001;26(13):1443-1447, discussion 1448 Ozer AF, Oktenoğlu BT, Sarioğlu AC. A new surgical technique: open-window corpectomy in the treatment of ossification of the posterior longitudinal ligament and advanced cervical spondylosis: technical note. Neurosurgery 1999;45(6):1481-1485, discussion 1485–1486 Karalar T, Unal F, Güzey FK, Kiris T, Bozdag E, Sünbüloglu E. Biomechanical analysis of cervical multilevel oblique corpectomy: an in vitro study in sheep. Acta Neurochir (Wien) 2004;146(8):813–818 Chibbaro S, Mirone G, Makiese O, George B. Multilevel oblique corpectomy without fusion in managing cervical myelopathy: long-term outcome and stability evaluation in 268 patients. J Neurosurg Spine 2009;10(5):458–465 Hirabayashi K, Miyakawa J, Satomi K, Maruyama T, Wakano K. Operative results and postoperative progression of ossification among patients with ossification of cervical posterior longitudinal ligament. Spine 1981;6(4):354–364