Comparison of Bony Fusion Between the Hollow Cage Group and the Cage with Bone Substitutes Group in One-level Cervical Spinal Disorders

ABSTRACT

OBJECTIVE: The aim of this study was to assess the clinical outcomes and bone fusion rates after insertion of hollow cages or cages with bone substitutes for treatment of disc protrusion in the cervical spine. METHODS: We performed a retrospective review of 93 patients who had undergone cage-assisted anterior cervical spine fusion. Patients were treated with hollow cages (N=52) or with cages with bone substitutes (N=41). Initial and follow up radiologic data were analyzed using Vavruch bone fusion criteria. RESULTS: Clinical outcomes including preoperative and postoperative pain and functional scores were not significantly different between the two patient groups. The over-all fusion rates differed between the two groups: patients treated with hollow cages demonstrated an average fusion rate of 84.6%, while patients treated with cages with bone substitutes demonstrated an average fusion rate of 87.8%, but these differences were not significant 24 months after surgery. At 18 months after surgery, the fusion rates of patients treated with cages with bone substitutes were significantly different from those of patients treated with hollow cages. Among patients who received bone substitutes, patients who received DBM exhibited better fusion outcomes than patients treated with other bone materials after 18 months of follow-up. CONCLUSION: Patients who are surgically treated with anterior cervical spine fusion for disc protrusion using cages with bone substitutes may achieve earlier fusion than patients treated with hollow cages, although both groups show similar final fusion rates.