Elsevier

World Neurosurgery

Volume 110, February 2018, Pages e362-e366
World Neurosurgery

Original Article
Posterior Cervical Laminectomy Results in Better Radiographic Decompression of Spinal Cord Compared with Anterior Cervical Discectomy and Fusion

https://doi.org/10.1016/j.wneu.2017.11.017Get rights and content

Background

Cervical spondylitic myelopathy is a degenerative condition resulting from chronic spinal cord compression and a leading cause of nontraumatic spinal cord dysfunction. The chief surgical goal in the management of cervical spondylitic myelopathy is adequate spinal cord decompression with or without fusion to slow or prevent further neurologic decline. We conducted a radiographic analysis of canal parameters preoperatively and postoperatively for patients undergoing either anterior or posterior cervical decompression.

Methods

Preoperative and postoperative radiographic analysis was performed using midsagittal and axial magnetic resonance imaging at the level of the disc space for 37 patients who underwent anterior or posterior cervical decompression. Statistical comparisons between anterior and posterior groups were performed using independent t test and Mann-Whitney U test where appropriate.

Results

Both postoperative anteroposterior canal diameter and posterior cerebrospinal fluid (CSF) space were greater in patients undergoing posterior decompression (P = 0.011 and P < 0.001, respectively), although postoperative anterior CSF space was comparable between both groups. Both anterior and posterior approaches to decompression resulted in a statistically significant improvement in anteroposterior diameter, anterior CSF space, and posterior CSF space (P < 0.001). Posterior decompression yielded significantly greater change in anteroposterior diameter and posterior CSF space compared with the anterior approach (P < 0.001).

Conclusions

In this quantitative radiographic study, we found that although both posterior cervical laminectomy and anterior cervical discectomy yielded significant decompression, laminectomy yielded a greater degree of decompression of the posterior CSF space.

Introduction

Cervical spondylitic myelopathy (CSM) is a degenerative condition resulting from chronic spinal cord compression and is a leading cause of nontraumatic spinal cord dysfunction.1 Patient presentation can vary from mild hyperreflexia to progressive weakness and gait dysfunction, and minor trauma can lead to devastating neurologic injury. If left untreated, 20%–60% of patients experience neurologic decline.2 Pathophysiologically, chronic compression of the spinal cord leads to vascular endothelial dysfunction and disruption of the blood–spinal cord barrier, resulting in neuroinflammation, hypoxia, and cell death. Spinal canal diameter is a major risk factor for developing symptomatic CSM,3, 4 and spinal canal parameters, such as sagittal diameter and cerebrospinal fluid (CSF) space for cord, have been shown to be significant predictors of spinal cord injury after mild trauma.5, 6

Although nonoperative management for symptomatic patients is generally not recommended,7 there is significant clinical equipoise within the literature regarding optimal surgical management.8, 9, 10 The chief surgical goal in the management of CSM is adequate spinal cord decompression with or without fusion to slow or prevent further neurologic decline. The 2 primary surgical strategies consist of 1) anterior decompression, via discectomy and/or corpectomy, and fusion and 2) posterior cervical decompression, via laminectomy with or without fusion or laminoplasty. Few large, prospective studies have directly compared anterior and posterior approaches,8 and pooled analyses have demonstrated conflicting results.10, 11, 12, 13 Moreover, although a number of studies have compared postoperative alignment between these 2 approaches,14, 15 few studies have assessed the degree of spinal cord decompression achieved by anterior versus posterior strategies. Given the importance of the degree of spinal cord compression in not only the development of CSM but also the risk of associated spinal cord injury with mild trauma, we conducted a radiographic analysis of canal parameters preoperatively and postoperatively for patients undergoing either anterior or posterior cervical decompression.

Section snippets

Materials and Methods

Patients undergoing surgical management of CSM from January 1, 2012, to March 1, 2017, in the University of Pennsylvania Health System were enrolled in this study. Patients <18 years of age, patients with isolated radiculopathy without cord compression, and patients who had combined approaches were excluded from the study. Patients who had both preoperative and postoperative magnetic resonance imaging (MRI) for any reason were investigated. Patient baseline and clinical variables were collected

Results

Over the study period, 37 patients were identified who underwent surgical treatment for CSM and who had both preoperative and postoperative MRI studies that were available for analysis. Of these patients, 22 underwent anterior cervical discectomy and fusion, and 16 underwent posterior cervical laminectomy with or without fusion. Baseline variables are listed in Table 1. Mean age for anterior and posterior groups was 55.3 years and 65.5 years, respectively (P = 0.008). Average time between

Discussion

In this quantitative radiographic study, we found that both posterior and anterior approaches to the treatment of CSM resulted in significant spinal cord decompression as assessed by AP diameter, anterior CSF space, and posterior CSF space. However, posterior laminectomy resulted in a significantly greater improvement in overall AP diameter and posterior CSF space. This result suggests that posterior laminectomy may be preferable to anterior cervical discectomy when spinal cord compression has

Conclusions

In this quantitative radiographic study, we found that although both posterior cervical laminectomy and anterior cervical discectomy yielded significant decompression, laminectomy yielded a greater degree of decompression of the posterior CSF space. This finding has important implications for choice of surgery in patients with a significant element of dorsal cord compression from ligamentous hypertrophy. Larger, prospective studies are needed to validate these findings and correlate with

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    Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

    Matthew Piazza and Brendan J. McShane contributed equally to this work and are considered co-first authors.

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