ANTERIOR OSTEOSYNTHESIS OF THE CERVICAL-S PINE WITH BIORESORBABLE SCREWS AND PLATES OF PHUSILINES - PRELIMINARY-RESULTS IN 5 CASES

The authors have designed a biocompatible and bioresorbable plate (1) in Phusilines for anterior cervical interbody stabilization. Phusilin es are polymer of alpha hydroxyacid (poly lactic acid), and their in vivo degradation (in lactic acid and via the Krebs circle, in water an d carbon dioxyd), is complete within 18 months. Screws are available i n the same material. Phusilines are radiotransparent and do not inter fer with MRI. The size and shape of the plate have been determined wit h three dimensional computed tomography, their thickness and their mol ecular weight and chemical structure have been determined to obtain th e best compromise in mechanical properties and time of resorption. Bio mechanical studies have been performed in cadaver, and have showed a g ood quality of the osteosynthesis. Five patients with anterior cervica l disco-ligamentar instability were operated on according the french l aw of bioethic (Huriet Law). In these five cases the operation was per formed via antero lateral approach, and it consisted in a interbody xe nograft with Surgibone (2) and interbody osteosynthesis with a plate a nd four screws of 16 mm of lenght and 4 mm of diameter. Clinical and r adiological examinations were realised during 18 months. In all cases, clinical results in rachialgia and neurological signs were excellent, in four case the tolerance was excellent, in a case inflammatory phen omens were observed the 8th and the 14th month succesfully treated wit h non steroid anti-inflammatories. Anatomical results were excellent i n two cases, good in two cases and incomplete in one case. Reasons of these incomplete results are discussed. These preliminary results are sufficent to continue these implantations.