Anterior Decompression and Interbody Fusion With BAK/C for Cervical Disc Degenerative Disorders

Study Design: A retrospective clinical study of 64 patients who underwent anterior cervical discectomy and fusion (ACDF) with BAK/C for disc degenerative disorders. Objective: To evaluate the long-term outcome of BAK/C in the treatment of cervical disc degenerative disorders. Summary of Background Data: ACDF has been demonstrated to be effective in the treatment of cervical disc degenerative disorders. BAK/C, a kind of thread cage widely used for interbody fusion in the lumbar spine, was used in the cervical spine to avoid the donor site complications of traditional autologous bone graft. Methods: Sixty-four patients with cervical disc degenerative disorders underwent ACDF with BAK/C technique in our institution between September 1997 and December 2000. All the patients were followed up for at least 6 years. The changes of segmental stability, bone fusion, cervical lordosis, and intervertebral height on radiographs were evaluated in detail immediately after operation, at 6 and 12 months postoperatively, and yearly thereafter. The clinical outcome of neurologic improvement and pain relief was also investigated. Results: Solid fusion was achieved at 1 year postoperatively in all patients, and the segmental stability was maintained during the whole follow-up. The cervical lordosis and intervertebral height were well restored immediately after operation, and gradually lost during the follow-up. Especially, the anterior height of intervertebral space decreased significantly after 1 year, when compared with the anterior height immediately after operation. BAK/C subsidence was observed in 9 patients, including 5 with 1-level fusion, 1 with 2-separated-level fusion, and 3 with 2-adjacent-level fusion, according to the standard of loss of intervertebral height more than 3 mm. BAK/C fusion was generally effective in the treatment of cervical disc degenerative disorders, according to the evaluation of neurologic improvement and pain relief. However, neck pain tended to reoccur in the patients with cage subsidence, and 2 of them even needed revision surgery because of the recurrence of myelopathy and progressive neck pain. Conclusions: Although BAK/C technique was generally effective and safe in the treatment of cervical disc degenerative disorders, the pitfalls of cage design resulted in the disability of maintenance of cervical lordosis and intervertebral height in the long-term follow-up. Cage subsidence, which tended to develop in the patients with 2-level fusion, was possibly responsible for the recurrence of neck pain.