Anterior cervical discectomy and fusion for noncontiguous cervical spondylotic myelopathy

Noncontiguous cervical spondylotic myelopathy (CSM) is a special degenerative disease because of the intermediate normal level or levels between supra and infraabnormal levels. Some controversy exists over the optimal procedure for two noncontiguous levels of CSM. The study was to evaluate the outcomes of the anterior cervical discectomy and fusion (ACDF) with zero-profile devices for two noncontiguous levels of CSM.

17 consecutive patients with two noncontiguous levels of CSM operated between December 2009 and August 2012 were included in the study. There were 12 men and 5 women with a mean age of 60.7 years (range 45-75 years). Involved disc levels were C3/4 and C5/6 in 11 patients and C4/5 and C6/7 in six patients. Preoperative plain radiographs, computed tomography (CT) with 3-D reconstruction and magnetic resonance imaging (MRI) of the cervical spine were taken in all patients. All radiographs were independently evaluated by 2 spine surgeons and 1 radiologist. The outcomes were assessed by the average operative time, blood loss, Japanese Orthopedic Association (JOA) score, improvement rate, neck dysfunction index (NDI), swallowing quality of life (SWAL-QOL) score, the cervical lordosis and complications.

The mean followup was 48.59 months (range 24-56 months). The average operative time and blood loss was 105.29 min and 136.47 ml, respectively. The preoperative JOA score was 8.35, which significantly increased to 13.7 at the final followup (P < 0.01). The NDI score was significantly decreased from preoperative 13.06 to postoperative 3.35 (P < 0.01). The operation also provided a significant increase in the cervical lordosis (P < 0.01) from preoperative 10.17° to postoperative 17.06°. The fusion rate was 94.1% at 6 months postoperatively, and 100% at 12 months after surgery. The mean SWAL-QOL score decreased from preoperative 68.06 to immediate postoperatively 65.65 and then increased to 67.65 at final followup. There was a statistically significant difference between preoperative and immediate postoperatively values (P < 0.05), but none between preoperative and at final followup (P > 0.05). Cerebrospinal fluid leak, dysphagia and radiological adjacent segment degeneration occurred in one patient, respectively.

The ACDF with zero-profile devices is generally effective and safe in treating two noncontiguous levels of CSM.