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time can be reduced as can the donor site morbidity. DePalma reported an acute donor site complication rate of 9% with 36% of the these patients having long term complaints. The complications can include hematoma, infection, and lateral femoral cutaneous nerve neuropraxy. It is therefore beneficial to find a material that can provide a better rate of fusion than autograft with less risk of graft collapse without increased risks of infection or rejection.
AUGMENTATION OF ALLOGRAFT
An demonstrated poor results using demineralized bone matrix (Grafton), and Vandenbent and Oosting demonstrated poor results with methacrylate. Therefore, a study was undertaken to determine the fusion rate and graft collapse using coralline hydroxyapatite augmentation to fibular strut allograft. Interpore 200 coralline hydroxyapatite granules are produced from the conversion of porities coral to the nonimmunogenic osteoconductive matrix of hydroxyapatite. The 200 micron pore size allows for the ingrowth of cortical bone. The coralline hydroxyapatite is not FDA approved for bone substitution in the spine, however, it is FDA approved as a bone void filler. This material was first synthesized by Constantz. Zdeblick (19), tested the cancellous coralline hydroxyapatite as the sole bone substitute in anterior cervical discectomies in the goat model. This preliminary study demonstrated excellent biologic compatibility and early creeping substitution of the implant by host bone.
METHODS
From 1996 to 1997, 48 patients who underwent outpatient anterior cervical microdiscectomy with allograft fibular strut fusion with or without coral chips were retrospectively reviewed. 20 of the operations were performed prior to the release of the Coralline hydroxyapatite chips. The patients were given the choice of allograft versus autograft, as well as the choice to use the coral chips or not. The fibular strut is freeze dried and obtained from the American Red Cross. It was cleaned in 70% ethanol, washed, sonicated, freeze-dried and stored.
PROCEDURE
The patient underwent general endotracheal anesthesia. The patient was placed supine on the operating room table with a roll longitudinally between his shoulders and the head on a donut minimally extended. The left horizontal intended incision from midline to the medial border of the sternocleidomastoid
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