Objective To evaluate the early outcome of anterior cervical discectomy and fusion (ACDF) using a Zero-profile implant system (Zero-P) for interbody fusion in the treatment of cervical spondylosis. Methods Between March 2010 and June 2011, 25 patients with cervical spondylosis underwent ACDF with Zero-P. There were 13 males and 12 females with an average age of 44.2 years (range, 26-67 years), including 14 cases of nerve root cervical spondylosis, 6 cases of spinal cervical spondylosis, and 5 cases of mixed cervical spondylosis. The disease duration was 3-120 months (median, 25 months). Single segment was involved in 20 cases, 2 segments in 4 cases, and 3 segments in 1 case. A total of 31 Zero-P were implanted (3 at C3, 4, 8 at C4, 5, 12 at C5, 6, and 8 at C6, 7). Primary cervical operation was performed in 23 cases and re-operation in 2 cases. Before and after operation, the height of intervertebral space and the cervical Cobb angle were measured; clinical outcome was evaluated using visual analogue scale (VAS) score for pain in the neck and upper limb, and Japanese Orthopaedic Association (JOA) score for myelopathy; and intervertebral fusion and the incidence of dysphagia were also observed. Results All incisions healed by first intention. All the patients were followed up 12-16 months (mean, 13.9 months). Interbody bone fusion was obtained, and the fusion time was 2.7-6.0 months (mean, 3.8 months). Three patients had dysphagia after operation; symptom disappeared at 1 week and 3 months after operation in 2 cases and 1 case, respectively. No fixation loosening, subsidence, or breakage occurred. The height of intervertebral space was significantly improved (P lt; 0.05) from (4.5 ± 0.5) mm at preoperation to (6.0 ± 0.7) mm at 1 week and (5.7 ± 0.6) mm at 12 months after operation; the cervical Cobb angle was significantly improved (P lt; 0.05) from (11.9 ± 6.1)° at preoperation to (21.2 ± 4.1)° at 1 week and (20.2 ± 3.7)° at 12 months after operation; and there was no significant difference between at 1 week and 12 months after operation (P gt; 0.05). The VAS score was significantly reduced (P lt; 0.05) from 7.1 ± 0.8 at preoperation to 1.9 ± 0.8 at 3 months and 1.0 ± 0.5 at 12 months after operation; the JOA score was significantly increased (P lt; 0.05) from 9.6 ± 1.3 at preoperation to 13.5 ± 1.0 at 3 months and 14.9 ± 1.0 at 12 months after operation; and there was significant difference between at 3 months and at 12 months after operation (P lt; 0.05). Conclusion The early outcome of ACDF using a Zero-P in the treatment of cervical spondylosis is satisfactory and reliable, and it can restore and maintain the cervical alignment and disc height, and disc has low incidence of postoperative dysphagia.
Objective To investigate the early effectiveness of Zero-profile interbody fusion system (Zero-P) in the treatment of cervical disc protrusion. Methods Between October 2010 and June 2012, 25 patients with cervical disc protrusion underwent anterior cervical discectomy and fusion (ACDF) using the Zero-P system. There were 15 males and 10 females, aged from 35 to 68 years (mean, 49 years). The disease duration was 3-26 months (mean, 10.5 months). Single segment was involved in all cases (2 cases in C3, 4, 5 cases in C4, 5, 11 cases in C5, 6, and 7 cases in C6, 7). The operation time and blood loss were recorded and analyzed. The visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, and neck disability index (NDI) were used to assess pain and nerve function improvement; the cervical Cobb angle was measured on the X-ray films before and after operation; according to Pitzen’s criteria, intervertebral fusion was evaluated. Results The operation was successful in 25 patients, with no severe complication. The average blood loss was 42.6 mL (range, 20-120 mL). The average operation time was 63.6 minutes (range, 45-90 minutes). Primary healing of incision was obtained in all cases; no injury of spinal cord and nerve root, cerebrospinal leakage, or deep infection occurred. The patients were followed up 6-23 months (mean, 14.5 months). No Cage subsidence and loosening, breaking, or pulling-out were observed. The symptoms and curvature of the cervical spine were obviously improved in all patients after operation. The VAS score, JOA score, NDI, and the cervical Cobb angle at 3 months and last follow-up showed significant differences when compared with preoperative ones (P lt; 0.05), but no significant difference was found between at 3 months and at last follow-up (P gt; 0.05). The interbody fusion was achieved in each operated segment of all patients according to Pitzen’s criteria. Conclusion The early effectiveness of ACDF with Zero-P system is satisfactory in treatment of cervical disc protrusion because it has the advantages of short operation time, less bleeding, good stability and restoration of the cervical alignment.