[Long-term efficacy of cervical artificial disc replacement for cervical degenerative diseases]

Objective: To evaluate the long-term efficacy of cervical artificial disc replacement for patients with cervical disc herniation and degenerative cervical canal stenosis. Methods: Total of sixty-eight patients underwent single-level Bryan artificial disc replacement in Beijing Jishuitan Hospital from December 2003 to December 2007 with a minimum 10-year follow-up were retrospectively analyzed. There were 43 males and 25 females with a mean age of (46±8) years. According to preoperative CT and MRI, the patients were divided into two groups: 27 patients in cervical disc herniation group and 41 patients in degenerative cervical canal stenosis group. The evaluation indexes before surgery and at last follow-up were compared between two groups. The clinical indexes included Japanese Orthopaedic Association (JOA) score, neck disability index (NDI) and Odom's grade; and the radiological indexes included the global and segmental range of motion (ROM), Cobb's angle at operated level. The continuous variable data were analyzed by independent sample t test. Results: In cervical disc herniation group, the improvement rate of JOA score was 83%±22%, NDI% decreased by 14%±9%, and Odom's grade was excellent in 17 patients, good in 10 patients. In degenerative cervical canal stenosis group, the improvement rate of JOA was 68%±34%, NDI% decreased by 11%±7%, and Odom's grade was excellent in 19 patients, good in 18 patients, fair in 4 patients. The segmental ROM was 10°±4° and 7°±6° in cervical disc herniation and degenerative cervical canal stenosis group at last follow-up (t=2.284, P=0.026). The global ROM was 50°±9° and 44°±14° in cervical disc herniation and degenerative cervical canal stenosis group at last follow-up (t=2.112, P=0.038). Conclusions: Cervical artificial disc replacement has a favorable long-term efficacy in treating cervical degenerative diseases. The postoperative global and segmental ROM in patients with cervical disc herniation are better than those in patients with degenerative cervical canal stenosis.