Abstract:

BACKGROUND: Anterior cervical discectomy and fusion is a classic surgical procedure for the treatment of cervical spondylosis. At present, we can use a Zero-P interbody fusion fixture and a traditional cervical anterior plate plus cage as an internal fixation material. The Zero-P has less postoperative esophageal interference and lower incidence of postoperative dysphagia compared with traditional anterior cervical plate fixation. Besides, the Zero-P could avoid the risk of excessively long or poorly placed plate injury to adjacent segmental intervertebral discs.

OBJECTIVE: To compare the safety and effectiveness between two-level anterior cervical discectomy and fusion using Zero-P and using traditional anterior cervical plate plus cage.

METHODS: Clinical data of sixty patients who underwent two-level anterior cervical discectomy and fusion in the Chengdu Third People’s Hospital from May 2016 to May 2018 were retrospectively analyzed. The patients were divided into Zero-P group (Zero-P fusion, n=30) and plate group (anterior cervical plate fixation combined with cage implantation, n=30). All patients in the two groups had informed consent to the treatment plan. This study was approved by the hospital ethics committee. The Japanese orthopedic association score, neck disability index score and Bazaz swallowing function score were used to evaluate the clinical efficacy. Cervical X-ray and cervical CT scans were performed to assess cervical curvature, observe bone graft fusion, and implant displacement, loosening and breakage.

RESULTS AND CONCLUSION: (1) All surgeries were successfully completed in 60 patients. The wounds healed in stage I after operation. There were no serious complications such as nerve injury, esophageal fistula, and cerebrospinal fluid leakage. (2) During the follow-up, there was no significant difference in neck disability index, Japanese orthopedic association score and bone graft fusion rates between the two groups (P > 0.05). (3) The incidence and severity of dysphagia in the Zero-P group were lower than those in the plate group at various time points after operation (all P < 0.05). (4) The overall curvature and operative segments curvature were better in the plate group than in the Zero-P group 6 months after surgery and in final follow-up (P < 0.05). (5) Two-level anterior cervical discectomy and fusion using Zero-P is a safe and effective operative method. The operation time, bleeding volume, number of fluoroscopy and postoperative dysphagia incidence were better than the traditional anterior cervical plate plus cage fixation system, but it is not as good as the traditional anterior cervical plate plus cage system in the curvature of the cervical spine. Zero-P is not recommended for patients with obvious abnormal cervical curvature before operation. 

Key words: Zero-P interbody fusion fixture, Zero-P, cervical spondylosis, anterior cervical plate, internal fixation, postoperative dysphagia