the invention provides a bioabsorbable screw , suitable for use in orthopaedic surgery , and having cavities disposed on the surface of the shaft . in particularly preferred embodiments of the invention , grating means are provided , and the screw shaft may be hollow , to assist eves biodegradation of the screw . the use of low melting point polymers further allows the screw to be melted in - vivo , producing increased fixation strength .