| 摘要 |
A screwdriver used during surgery for re-joining two pieces of a fractured bone in cooperation with a connector plate adapted to be secured to a first one of the two bone pieces. The connector plate has at least one screw-threaded bore with its axis being directed at a second of thed bone pieces through a pre-drilled portion of the first bone piece. A screw has a screw-shaped inner end for, as the screw is driven with forceful rotation, initially biting into the bone upon passing through the bore of the connector plate and out of the pre-drilled portion of the first bone piece, such screw having an outer end adapted to be engaged with the screwdriver. A sleeve of a shorter length than the screw is axially movable and rotatable on the screw, such sleeve having an outer end provided with a screw thread corresponding to the screw thread in the bore of the connector plate for threaded engagement therewith. The screwdriver includes a first shaft unit arranged to have its inner end engage the screw to move the screw axially and to rotate the screw. A second shaft unit is axially movable and rotatable relative to the first shaft unit and is arranged to have its inner end rotate the sleeve. Axial movement of the first shaft unit moves the screw engaged therewith outward relative to the sleeve so that the outer end of the screw passes through the sleeve and into the second shaft unit to a position therein such that the inner end of the screw protrudes inwardly from the inner end of the sleeve by a length such that the threaded outer end of the sleeve can be threadedly engaged with the bore of the connector plate before the screw is driven to have the inner end of the screw initially bite into the bone beyond the pre-drilled portion.
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