Study design: This is a prospective study of artificial disk replacement combined with cage fusion for the treatment of multilevel cervical disk herniation.
Objective: To evaluate the clinical outcome of Bryan cervical disk replacement combined with adjacent segment cage fusion in the treatment of patients with multilevel cervical disk herniation. To observe neurological improvement and interpret the radiographic findings.
Summary of background data: It is generally considered that 1-level cervical disk replacement had an excellent intermediate clinical outcome. There was no final conclusion about the disk replacement for the treatment of multilevel cervical disk disease. The negative factors include possible complication, high cost, and contraindication for disk replacement at one of the multisegments. Disk replacement combined with adjacent segment cage fusion may be an option for the treatment of multilevel cervical disk disease for certain patients.
Methods: There were 26 patients with multilevel cervical disk herniation who underwent 1-level disk replacement and adjacent segment cage fusion. Of the patients, there were 17 male and 9 female, aged between 35 and 63 (mean age 47 y). The herniated disk was located at C3-C4, C4-C5 in 1 case, C4-C5, C5-C6 in 11cases, C5-C6, C6-C7 in 7 cases, C4-C5, C6-C7 in 3 cases, and C4-C5, C5-C6, C6-C7 in 4 cases. There were 12 cases with myelopathy and 14 patients with radiculopathy. The stabilization and the range of motion of implanted disk, the fusion of cage, and the displacement of cage were observed on dynamic radiograph postoperatively. The clinical symptoms and the neurological functions were evaluated based on the Japanese Orthopaedic Association Scale score (17 points), neck disability index score, and Odom's Criteria.
Results: All patients underwent 1-level Bryan disk replacement and cage fusion on adjacent segment. The replacement segment and fusion segment were located next to each other among 23 patients. They were not next to each other in 3 cases. The follow-up was 24 to 47 months. Definite stabilization was achieved for all Bryan disks. The average range of motion at replaced level was 9.5 degrees postoperatively. Solid fusion was achieved in all cages. There was no subsidence or displacement of cage. The Japanese Orthopaedic Association Scale score (17 points) rose from 9.2 to 13.5 at final follow-up. The neck disability index was reduced from 40.8 to 28.5 at final follow-up. The clinical success (excellent/good/fair) based on Odom's Criteria were 84.6%.
Conclusions: Definite stabilization and satisfactory mobility were achieved after cervical disk replacement and cage fusion. This provides an effective option for the treatment of multilevel cervical disk herniation. The evaluation of high fusion rate of cage may need to accumulate more clinical cases.