[Results of cervical interbody fusion with coral grafts]

We present the long term clinical and radiological results of a retrospective series of 46 cervical interbody fusions using coral grafts performed in 38 patients.

The patients were treated for prolapsed discs (19 cases) or cervical spondylosis (19 cases) with a clinical presentation of either radiculopathy (31 cases) or myelopathy (7 cases). We have done a post-operative clinical analysis of cervicoscapulalgia and radiculo-medullary symptoms and a radiological comparison of the change of the cervical spine angulation, the loss of height and the fusion rate at the graft site.

The early clinical postoperative outcome showed that 10 out of 20 patients with excellent radiculo-medullary results had cervicoscapulalgia and 13 out of 18 patients with partial improvement had cervicoscapulalgia. No poor results according to our classification were noted. The late clinical outcome (average follow-up of 16 months) showed that 15 patients out of 31 had radiculo-medullary degradation and 24 presented with cervicoscapulalgia. Sixteen out of 20 patients had a loss of lordosis (range 6.2 degrees; SD 1.2) and 17 a loss of height (range 11.3%; SD 1.5). After 2 years, 13 out of 20 grafts were still hyperdense compared to the adjacent bone, and 8 had a hypodense peripheral edge.

Coral grafts of this series have not been able to keep a physiological sagittal balance of the cervical spine, which is probably one of the essential factors to prevent postoperative cervicoscapulalgia. In the same way, the loss of height of the fused segments, by narrowing of the intervertabral foramen, may explain some further radiculo-medullary deterioration.