关键词: 植入物, 脊柱植入物, 颈椎病, 椎间融合器, Zero-P, 内固定, 椎体高度, 椎体稳定性, 异位骨化

Abstract:

BACKGROUND: Anterior interbody fusion has been used to treat cervical degenerative diseases for more than 50 years, but the standardization of its technique remains controversial. The major disadvantages of alone use of interbody fusion cage are instant poor stability and fusion subsidence. The main disadvantages of interbody fusion with anterior titanium plate are dysphagia in the plate region and heterotopic ossification around the operated intervertebral disc side.
OBJECTIVE: To compare clinical and radiological efficacies of new implant Zero-P and traditional fusion with titanium plate for treatment of nerve root cervical spondylosis.  
METHODS: We retrospectively analyzed clinical data of 56 patients with nerve root type cervical spondylosis undergoing anterior cervical decompression and fusion fixation. They were divided into two groups according to fixation scheme. Zero-P group contained 25 patients with 31 segments. Traditional group (traditional intervertebral fusion device + locking titanium plate) contained 31 patients with 40 segments. There were no significant differences in age, gender and operated regions between above two groups. Cervical dysfunction index, the incidence of dysphagia, Cobb C angle, Cobb S angle, vertebral height, vertebral stability and heterotopic ossification degree were compared between the two groups.
RESULTS AND CONCLUSION: Cervical dysfunction index was significantly lower at 24 months after fixation than before fixation in both groups (P < 0.05). Patient’s symptoms were obviously improved after fixation. One patient affected dysphagia in early stage after fixation in the Zero-P group. Symptoms disappeared during 24-month follow-up. Two patients experienced dysphagia in the traditional group after fixation. No significant difference in the incidence of dysphagia was detected between the two groups (P > 0.05). No significant differences in Cobb C angle and vertebral height of surgical segment were detectable before and after fixation in the two groups (P > 0.05). Cobb S angle apparently increased in the Zero-P group from pre-fixation to post-fixation (i.e., surgical procedures). The maximum appeared in the first rechecking after fixation. In the traditional group, Cobb S angle slowly increased from pre-fixation to 6 weeks post-fixation, and peaked at 6 weeks post-fixation. Solid bony fusion was visible in the fusion segment in all cases of the Zero-P group, but solid body fusion was found in 30 cases of the traditional group, with a stable rate of 97%. In 24-month follow-up, the incidence of heterotopic ossification was 25% in the Zero-P group, but 44% in the traditional group. The rate of heterotopic ossification was significantly lower in the Zero-P group than that in the traditional group at 24 months after fixation (P < 0.05). These data suggested that compared with traditional pegboard system, Zero-P implant for treatment of nerve root cervical spondylosis has a certain advantage, and deserves to be used in the clinic.

Key words: cervical vertebrae, internal fixators, deglutition disorders, follow-up studies