RESUMO
Objective: To evaluate the influence of the shell angle of cervical artificial disc on long-term effectiveness of cervical artificial disc replacement (CADR). Methods: The clinical data of 71 patients who were treated with single-level CADR with Bryan prosthesis between December 2003 and December 2007 and followed up more than 10 years, were retrospectively analyzed. There were 44 males and 27 females with an age of 26-69 years (mean, 45.9 years). According to the shell angle of the cervical artificial disc which was measured on the postoperative lateral X-ray film, the patients were divided into kyphotic group (shell angle was negative) and non-kyphotic group. The following evaluation indexes before operation and at last follow-up were compared between 2 groups. Radiographic indexes included the range of motion (ROM) of cervical spine, the ROM of operated level, Cobb angle of operated level (the negative value indicated that the segmental kyphosis occurred at operated level), paravertebral ossification (PO) grades (grades 3 and 4 were high grade PO). Clinical indexes included Japanese Orthopaedic Association (JOA) score, neck disability index (NDI), and overall effectiveness evaluation (Odom criteria). Results: There were 24 patients in kyphotic group and 47 patients in non-kyphotic group. There was no significant difference in baseline data including gender, age, and operated level between 2 groups ( P>0.05). All the patients in 2 groups were followed up 121-165 months (mean, 128 months). There was no significant difference in preoperative ROM of cervical spine and ROM of operated level between 2 groups ( P>0.05); but the preoperative Cobb angle of operated level in kyphosis group was significantly lower than that in non-kyphotic group ( t=2.636, P=0.013). There was no significant difference in ROM of cervical spine at last follow-up between 2 groups ( t=1.393, P=0.168), however, the ROM and the Cobb angle of operated level in kyphotic group were significantly lower than those in non-kyphotic group ( P0.05). Conclusion: The shell angle of cervical artificial disc may lead to a decrease in the postoperative segmental ROM, and an increased occurrence of segmental kyphosis and high incidence of PO.
RESUMO
Objective: To evaluate the long-term efficacy and influencing factors of cervical artificial disc replacement (CADR) for patients with cervical spondylotic radiculopathy (CSR). Methods: 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 (ROM0.05). Except that the loss of ROM (ROM0.05). The results of clinical evaluation indexes showed that the NDI was significantly improved in both groups ( P0.05). The excellent and good rate of overall efficacy reached 100% in both groups. Conclusion: 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.