BIOABSORBABLE RODS AND PINS FOR FIXATION OF METACARPOPHALANGEAL ARTHRODESIS OF THE THUMB

We report results on the use of bioabsorbable pins and intramedullary rods made of high-molecular-weight polylactic acid in both experimenta l and clinical conditions. In the experimental study, bioabsorbable ro ds were implanted in rabbit femora. Histologic assessment on nondecalc ified bone showed that resorption of the material began at 4 months af ter implantation and gradually fragmented over a period of 3 years. In 12 patients 13 metacarpophalangeal joints of the thumb were arthrodes ed by using one bioabsorbable intramedullary rod with one or two obliq ue pins. All joints fused within 6 to 8 weeks. During that period ther e was no sign of inflammation, and there were no nonunions. Postoperat ive magnetic resonance imaging assessment was done in all rabbits and eight patients. This modality is a useful tool in postoperative evalua tion of the position and shape of the rod but is not sufficiently sens itive to assess the presence of local inflammation and the rate of res orption of the rods.