[Changes in the pronosupination caused by resection of the radius head and prosthetic replacement. Anatomical study...

To improve the contribution of the radio ulnaris superior joint to the unrolling of pronation supination motion, we have set an anatomical and functional study with 20 cadaveric forearms. The first part concerned measures of the radial head diameters, which confirm its constant ovality, nevertheless unsufficient to create a "cam effect" likely to permit the passage of tuberositas radii over the ulna. The second part was supposed to evaluate the modifications of the pronation supination amplitude with fixed ulna, following radial head resection and prosthetic replacement. This study permitted to obtain relatively equivalent graphs in these circumstances; the prosthetic group realises the most important average range of motion, and graphics with the most approximating isocentrical arc of circles aspect. As a conclusion, no experimental argument seemed sufficient for us, to make a better choice between radial head resection and prosthetic replacement.