SCREW AND DRIVER

摘要

2026781 9008510 PCTABS00001 A screw (20) and driver (50) combination designed so that the screw (20) is releasably axially couplable with the driver (50) and so that the screw (20) is positively rotatably engageable with the driver (50). The screw (20) comprises an axial bore (26) of circular cross section and a counterbore (28) of polygonal cross section. The driver (50) comprises a radially-compressible front portion (66) sized to engage the axial bore (26) of the screw with a minor spring interference fit and an intermediate portion (56) sized to positively rotatably engage the counterbore (28) of the screw (20). The screw (120) and driver (150) may be adapted for use with a guide wire insertion system by providing axial bores (125, 185) extending through the entire lengths of the screw (20) and driver (50). The driver (250) may include a mechanical expansion assembly (297) for causing said front portion to expand radially.