[Absorbable osteosynthesis: experimental and clinical approach in surgery of the hand]

Given the advances in the field of high molecular-weight polylactides, it is now possible to obtain biomaterials of great strength with a resorption rate that ranges from a few months to several years. Experimental evaluation of the biomaterials was done in rabbits with implantation of intramedullary rods after fracture of the knee. The results of histological studies and assessment, using MR imaging, indicated good compatibility of the intramedullary rods. Applications for human clinical practice centered on metacarpophalangeal arthrodesis of the thumb performed for rheumatoid polyarthritis and intractable sprains of the metacarpophalangeal. Operations were performed on 52 patients with a rate of consolidation of 96%. No synovitis-like reactions were observed concurrent with massive release of the biomaterial. As a first step, this type of osteosynthesis could be applied to the upper extremity where stresses are relatively minimal. Eventually, screws of reduced diameter could be developed for the treatment of articular and unstable fractures of the metacarpophalangeals. There are already 3.5 mm-screws that can be used for malleolar fixation at the level of the lower extremity. Because of the wide variety of biomaterials that are currently available, it is important to be familiar with their composition, so that patients will be spared certain complications linked to resorption, especially inflammatory reactions. The biomaterials presented here belong to a class of biomaterials that have demonstrated good compatibility. At the present time, the cost of biodegradable materials remains high but it is important to emphasize the social and economic consequences of their use, since there is no need for a secondary procedure to remove them.