[Long-term clinical efficacy of cervical artificial disc replacement for cervical spondylotic radiculopathy]

To evaluate the long-term efficacy and influencing factors of cervical artificial disc replacement (CADR) for patients with cervical spondylotic radiculopathy (CSR).

The data of 29 CSR patients who underwent Bryan artificial disc replacement between December 2003 and December 2007 and followed up more than 10 years were retrospectively analysed. There were 16 males and 13 females with an average age of 54.1 years (range, 40-70 years). The disease duration was 2-144 months (mean, 19.2 months). CT and MRI were performed before operation to identify the compression segments (C _{3, 4} in 2 cases, C _{4, 5} in 6 cases, C _{5, 6} in 18 cases, C _{6, 7} in 3 cases) and the compression factors. According to the compression factor, the patients were divided into 2 groups: 14 patients with cervical disc herniation were in the group A and 15 patients combined with osteophyte were in the group B. There was no significant difference in gender, age, disease duration, and compressed level between 2 groups ( P>0.05). The radiographic and clinical evaluation indexes were recorded before operation and at last follow-up. The radiographic evaluation indexes included the global cervical and segmental range of motion (ROM), loss of ROM (ROM<3°) at last follow-up, Cobb angle and incidence of local kyphosis, paravertebral ossification (PO) grading. The clinical evaluation indexes included neck disability index (NDI) and overall efficacy (Odom's score).

All patients were followed up 121-153 months (mean, 130 months). The results of radiographic evaluation indexes showed that within group comparison, except that the Cobb angle of the operated level was significantly decreased ( P<0.05) in both 2 groups, there was no significant difference in global cervical ROM and segmental ROM between preoperation and last follow-up ( P>0.05). Except that the loss of ROM (ROM<3°) at last follow-up and high-grade PO at last follow-up in group B were significantly higher than those in group A ( P<0.05), there was no significant difference in other radiographic evaluation indexes between 2 groups ( P>0.05). The results of clinical evaluation indexes showed that the NDI was significantly improved in both groups ( P<0.05) at last follow-up. There was no significant difference in the NDI at preoperation and at last follow-up, the decline of NDI at last follow-up, and the overall efficacy evaluated by Odom's score between 2 groups ( P>0.05). The excellent and good rate of overall efficacy reached 100% in both groups.

CADR has satisfied long-term efficacy in treating CSR. The maintenance of segmental mobility was better in patients with disc herniation than in patients with disc herniation and osteophyte.