Safety of Surgical Decompression for Cervical Myelopathy Shown

Treating (and relieving) spinal cord compression with surgery has long-term benefits for patients, a large clinical trial has proven.

“Surgical decompression for cervical spondylotic myelopathy (CSM) is highly effective and safe,” said Michael G. Fehlings, M.D., Ph.D, FRCS, professor of neurosurgery and director of the University of Toronto Neuroscience Program. “The duration of clinical symptoms has an adverse impact on outcomes, and hence earlier diagnosis and referral is important.”

CSM is the most common cause of spinal cause dysfunction around the world. The condition mostly affects older adults, as the natural aging process results in degenerative changes in the cervical spine that can compress the spinal cord. Such compression can lead to muscle weakness, impaired walking and hand control, spasticity and bladder control problems and significant neck and arm pain.

While the condition is treatable by surgery, doctors have never been sure whether an operation can produce a long-term sustained benefit. To answer this question, Fehlings and his colleagues in the AOSpine North America Clinical Research Network enrolled 280 patients with clinically symptomatic CSM in a multi-center, controlled, cohort clinical trial. Forty percent of the patients were women and 26 percent were smokers. The patients‘ average age was 56 and the average number of spinal levels operated on was 3.8.

The researchers used the modified Japanese Orthopaedic Association (mJOA) score, the Nurick score, the SF-36 and the Neck Disability Index to measure outcomes. Patients underwent anterior (n=169), posterior (n=97) or circumferential (n=14) decompression/reconstruction surgery, according to Fehlings. All patients completed one year of follow-up, and 183 patients have completed two years of follow-up.

Improvements in generic and patient-specific outcomes were significant at one year, with results maintained at two years, according to the clinical trial results. From baseline to two years, the mJOA scores rose 3.02 points, the Nurick Score improved by 1.64 points, the Neck Disability Index climbed 11.06 points, the SF-36 physical component summary score increased by 5.7 points and the SF-36 mental component summary score rose by 4.89 points.

Fehlings was not surprised by the trial’s overall results. However, he was confounded by two outcomes: that surgery was effective in patients with mild cases of CSM (those who had an mJOA score of 15 or higher); and that symptom duration had an obvious effect on treatment outcomes.

“Sixmonths appears to be a significant cut-point,” Fehlings said Oct. 7 during the presentation of his findings at the North American Spine Society’s 25th Annual Meeting in Orland, Fla. “Patients with less than six months of symptoms do better; however, even patients with chronic symptoms improve with surgery.”