[Comparing loss of anterior column height and cervical Cobb angle with three different types of anterior cervical discectomy and fusion].
OBJECTIVE
To compare the loss of anterior column height and cervical Cobb angle with three different types of anterior cervical discectomy and fusion (ACDF).


METHODS
A prospective randomized study was performed on 60 patients who had undergone ACDF with the autologous iliac crest graft (group A, n=20), the autogenous bone and the anterior cervical locking plates (group B, n=20), and Syncage-C filled with the local autograft reamings (group C, n=20) from January 1998 to January 2003. The patients diagnosed as having cervical radiculopathy (RP) and cervical spondylotic myelopathy (CSM) were indicated for ACDF. Of the patients, 41 were male and 19 female with a mean age of 57 years (range, 36-68) and their average course of disease was 6.2 months (range, 1-36). There were 36 one-level and 24 two-level fusions from C(3,4) to C7, T1. Radiological measurements were performed on the cervical radiographs taken before operation, 7 days and 3 months after operation, and on the last day of the follow-up; then, the height and Cobb angle of the fused segment, functional restoration, and clinical outcome were evaluated in the three groups.


RESULTS
The follow-up of more than 2 years (range, 2-7) showed that the average loss of anterior column height and Cobb angle of the fused segments in groups A and B, which had not preserved the endplate, had a greater increase than that in group C, which had preserved the endplate. Of the patients, 12 had autograft collapse, 3 autograft displacement, and 10 postural abnormality between the fused segments, most of which happened in groups A and B. The fusion rate was 93.3% (56 cases) according the strict arthrodesis criteria; their excellent and good rate in the functional assessment was 83.3% (RP 90.4%, CSM 79.5%); the overall satisfactory (excellent and good) rates in groups A, B and C were 75%, 85% and 90%, respectively.


CONCLUSIONS
To increase the resistance to graft subsidence, which is a major reason for narrowness of the fused segments, and to maintain normal cervical curvature, we should improve our skills of bone grafting performance, preserve the endplate, carefully evaluate the degree of osteoporosis before operation, and use anterior cervical locking plate and/or fusion with Syncage-C when necessary.
Tan
Junming
J
Department of Orthopaedics, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, PR China.
Ye
Xiaojian
X
Yuan
Wen
W