Surgery for Degenerative Cervical Myelopathy

What Really Counts?

Oliver Gembruch, MD; Ramazan Jabbarli, MD; Ali Rashidi, MD; Mehdi Chihi, MD; Susann Hetze, MD; Lennart Barthel, MD; Adrian Toplak, MD; Nicolai El Hindy, MD; Ulrich Sure, MD; Philipp Dammann, MD; Neriman Özkan, MD

Disclosures

Spine. 2021;46(5):294-299. 

In This Article

Abstract and Introduction

Abstract

Study Design: Retrospective study (data analysis).

Objective: The purpose of this study was to assess the role of different factors on postoperative outcome of patients with degenerative cervical myelopathy (DCM).

Summary of Background Data: Ongoing degenerative changes of DCM lead to progressive neurological deficits. The optimal timing of surgical treatment is still unclear, especially in patients with mild DCM.

Methods: Patients with DCM treated in our clinic between 2007 and 2016 were retrospectively analyzed. Pre- and postoperative neurological function was assessed by the modified Japanese Orthopaedic Association Score (mJOA Score) at different stages. The minimum clinically important difference (MCID) was used to evaluate the improvement after surgery. The comorbidities were recorded using the Charlson Comorbidity Index (CCI). Possible associations between age, sex, CCI, preoperative symptoms duration, high signal intensity (SI) on T2-weighted magnetic resonance imaging (MRI) with mJOA Score and MCID were analyzed using univariate analysis and multivariate regression models. Additionally, subgroup analysis was performed according to the severity of DCM (mild: mJOA Score ≥15 points; moderate: mJOA Score of 12–14 points; and severe: mJOA Score <12 points).

Results: The mean age of the final cohort (n = 411) was 62.6 years (range: 31–96 years), 36.0% were females. High SI on T2-weighted MRI was detected in 60.3% of the cases. In the multivariate analysis, patients' age (P = 0.005), higher CCI (P = 0.001), and presence of high SI on T2-weighted MRI (P = 0.0005) were associated independently with lower pre- and postoperative mJOA Score and postoperative MCID. Subgroup analysis revealed age and high SI on T2-weighted MRI as predictors of pre- and postoperative mJOA. However, symptom duration did not influence neurological outcome according to the severity of DCM.

Conclusion: Surgery for DCM leads to significant functional improvement. However, better outcome was observed in younger individuals with lower CCI and absence of radiographic myelopathy signs. Therefore, DCM surgery, particularly before occurrence of high SI on MRI, seems to be essential for postoperative functional improvement regardless the above-mentioned confounders.

Level of Evidence: 3

Introduction

Degenerative cervical myelopathy (DCM) is the most common degenerative disease.[1] It is an age-depending, ongoing degeneration caused by progressive stenosis of the cervical canal, leading to the compression of the spinal cord.[2]

Nonspecific neck and shoulder pain, with or without radiculopathy, sensory deficits, numbness and fine motor deficits, ataxic gait, and sphincter dysfunction are examples of the highly variable spectrum of clinical symptoms of DCM.[3] Different clinical features of DCM reflect the complex interaction of mechanical and vascular factors; hence DCM requires various surgical and nonsurgical treatment strategies.[3]

However, only a few accepted guidelines for DCM treatment exist, especially for mild DCM.[4] Surgical decompression is currently the criterion standard for the treatment of moderate and severe DCM.[4] Conservative therapy should only be performed in mild DCM[4,5] because it does not result in recovery of neurological symptoms and the results are significantly less favorable than surgery in cases of moderate and severe DCM.[6]

Over the recent years, the interest of scientific research was focused on the analysis of predictors of neurological outcome after DCM surgery, due to its increasing epidemiologic relevance. Up to date, several factors possibly influence the neurological outcome. Factors such as age, comorbidities, preoperative modified Japanese Orthopaedic Association Score (mJOA Score), smoking status, or duration of symptoms[7–9] were identified. Interestingly, the approach (anterior versus posterior),[10–14] type of surgical treatment (i.e., anterior cervical discectomy and fusion, laminoplasty or laminectomy),[13,15] or the number of operated levels[10,12,13,16] did not influence the neurological outcome.

Nevertheless, surgical timing and the therapy of patients with a high signal intensity (SI) on magnetic resonance imaging (MRI) and mild neurological deficits are still various.

The aim of our study was to analyze the factors influencing preoperative neurological status and postoperative neurological outcome of patients with diagnosed DCM. Furthermore, we assessed outcome predictors with regards to the severity of DCM (mild, moderate, and severe).

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