ABSTRACT
Objective To evaluate the effects of allograft fusion cage(AFC) on anterior cervical interbody fusion. Methods AFCs were implanted in 61 degenerative cervical intervertebral spaces of 39 cases, who needed anterior cervical interbody fusion from September 1995 to December 1999. 31 cases were diagnosed as cervical spondylolysis， 2 cases as acute protrusion of cervical intervertebral disc and 6 cases as fracture and dislocation of cervical spine. The clinical effects and complications were observed, and the postoperative presentations of X－ ray examination of cervical spine were also evaluated. Results Thirty- nine cases were followed up with a mean period of 28.6 months. No neurologic complications appeared, and no AFCs shifted or dislocated. The clinical effects were satisfactory. 61 intervertebral spaces were confirmed to be solid fused completely by constant X－ ray examination at 3.9 months in average after operation. There were no collapse or angular deformities in 59 spaces of them,the other 2 spaces lost a little height because of removal of external fixation too early. Conclusion The implantation of AFC was simple, stable, less injury with similar intervertebral osseous fusion rate compared to the conventional anterior cervical interbody fusion. Forthermore, the implantation of AFC does not need auto iliac crest graft or the use of metal fixations. Some complications caused by implanting auto iliac crest and metal fixations can be avoided.
ABSTRACT
Objective\ To evaluate the immediate effects and strength of allograft fusion cage(AFC) used for reconstructing stability of cervical spine. Methods\ Discs of C 5 and C 6 were resected on 8 fresh human cervical spine specimens, and autogenous iliac bone grafts(AIBG), and AFCs were implanted into the intervertebral spaces respectively. Compression test, pull out test and segmental motion measurement were studied.Results\ Comparing with intact and AIBG groups, the range of motions of C5-6 in AFC group were decreased in all directions except for extension; with (502?114) N compressive load,the vertebrae in AFC group were broken while the AFC were intact, but the AIBG were broken at (135?42) N load; with 300 N drawing load,no loosening was found between AFCs and vertebra, but it was found between AIBG and vertebra at 60 N load. Conclusion\ AFC could provide enough support,anti slide ability and could remain or increase the height of intervertebral spaces. It completely meets clinical and biomechanical requirements.