Preliminary Experiences with Interbody Titanium Cage(RABEA(TM)) Fusion in Patients with Degenerative Cervical Disease

OBJECTIVE: The purpose of this study is to evaluate the safety and efficacy of cervical interbody fusion with implantable titanium cage(RABEA(TM)). The authors retrospectively analysis the result of application of cervical hollow cage(RABEA(TM)) without bone graft to the patients of degenerative cervical disease. METHODS: 78 patients with radiculopathy with or without myelopathy due to degenerative cervical diseases were underwent anterior cervical discectomy and interbody fusion with titanium cages(RABEA(TM)) which were not filled with autogenous bone from June 1999 to December 2002. Among them, 33 patients could be followed-up for at least 6 months. Mean follow-up period was 13.3 months(ranged 6-30 months). RESULTS: Good or excellent results were found in approximately 82.0%. Preoperatively, the mean height of the disc space was 4.27mm(range 3~6mm), and at 1 day postoperatively it was 7.87mm(range 7~9mm). The mean height of the disc space after 1 year was 6.07mm(range 1~8mm). Due to subsidence of cage, 7 patients showed decrease of disc space height to preoperative disc space height. Among them, 1 patients showed poor results. A solid fusion was achieved in all patients. In this context, causes of subsidence are represented by osteoporosis and degree of cage recess. CONCLUSION: Titanium cages appear safe and effective in the treatment of degenerative cervical disease. But subsidence of cage, so far limited in number, appeared to be important risk factor for recurrence of the symptoms.

Anterior Cervical Bisegmental Interbody Fusion with Titanium Cage(RABEA) in Degenerative Cervical Disease: Comparative Analysis with Monosegmental Interbody Fusion

OBJECTIVE: It is not uncommon to perform anterior discectomy for two adjacent disc levels in degenerative cervical disease due to diagnostic problems. The purpose of this study is to assess the effectiveness of titanium cage(RABEA) applied to two-level cervical degenerative disc disease, which is compared with the result of fusion with the same cage for one-level disc disease. METHODS: Between January 1999 and March 2003, 52 patients with degenerative cervical disease underwent anterior discectomy and interbody fusion with titanium cage(RABEA). Among them, 23 patients could be followed-up for more than 1 year. Ten patients received interbody fusion at one disc level(Group A), and 13 patients at two adjacent disc levels(Group B). Clinical outcome, fusion rate, disc space height and change of lordotic angle were analyzed in both groups. RESULTS: Clinical outcome according to Odom's criteria was excellent and good in 9(90%) of Group A and 11(84.6%) of Group B. The bone fusion rate of Group B was slightly lower than that of Group A. The height of disc space was well maintained until 1 year postoperatively in both groups. The change of the cervical lordotic angle has no significant difference between the two groups. CONCLUSION: Interbody fusion with titanium cage(RABEA) for two-level degenerative cervical disease may be an acceptable treatment modality due to relatively good clinical outcome despite slightly low fusion rate.

Clinical Application and Surgical Results of Hollow Cage(RABEA(TM)) without Bone Graft in the One-Segment Cervical Spinal Interbody Fusion

OBJECTIVE: The authors report a result of application of cervical hollow cage(RABEA(TM)) without bone graft to the patients of one-level cervical spondylosis or acute cervical disc herniation to fill and stabilize a vacant space following anterior decompression. METHODS: Twenty-one patients from May 1999 to April 2001 had been taken procedure with cervical hollow cage system following anterior decompression and there had been no additional bone graft or screw fixation or fusion. Pain relief and clinical outcome were evaluated, and the intervertebral disc height and segmental angle for radiological assessment were examined. All patient were followed up for 12 months at least. RESULTS: The result was excellent in 14 cases(66.7%), good in 6 cases(28.6%) and poor in 1 case(4.8%). In the lateral projection, the mean of preoperative disc height and segmental angle were significantly improved after surgery and maintained during follow-up periods. No abnormal displacement were recorded at dynamic flexion and extension lateral X-ray and no cage rotation or retropulsion was noted in follow-up periods. Three patients(14.3%) was observed to subside of disc height on the postoperative periods and only one of their patients was dissatisfied with surgery. CONCLUSION: Cervical hollow cage is simple to perform and reduces the operation time. Besides clinical improvement, it improves mechanical stability and radiological profile as the physiologic level. The cervical hollow cage might be an alternative to traditional cervical interbody fusion with bone graft.