Patent ID: 7578836

Claim:
A system for repairing a tissue injury in a patient, the system comprising a screw having: a root having a proximal end and a distal section having a narrowing cross section toward a distal end; a thread atop the root along at least a portion thereof between the proximal end and the distal end, the thread having a helical pitch having a substantially constant value along a leading section extending proximal of the distal end and having a variable value along a trailing section extending proximal of the leading section, wherein the helical pitch decreases along the trailing section to the proximal end of the root, the thread further having a leading face facing the distal end, the leading face making a first angle with a helical axis having a directionality pointing from the proximal to the distal end, the first angle decreasing from a first oblique angle adjacent the distal end to a second oblique angle adjacent the proximal end, the second oblique angle smaller than the first oblique angle; and an axial bore at least partially therethrough generally along a helical axis proceeding from the proximal end and into the root, the bore having a noncircular cross-sectional shape; and an elongated driving device having: a distal end having means for mating with the bore; a proximal end having means for being rotationally driven; and a noncircular cross-sectional shape along a distal section adjacent the distal end, the distal section dimensioned for entry into the bore and to permit relative axial sliding and rotational coupling movement therebetween.