Fixer for pedicle screw mountings uses single tool to insert and clamp screw in mounting via tool-receiving screws and overall lockscrew for positive fit.

摘要

The screws (18,19) clamping the mounting (1) to connector (2) and pedicle screw (3) each have a receiver for a positively inserted turning tool as used to screw the pedicle screw (3) into its receiver (12). These receivers (12) form internal polygons suited to the tool and the head (5) of the pedicle screw (3) issuing from the vertebra enters a bore (13) of suitable diameter within the main mounting (1). The pedicle screw is held in thus by a lockscrew (18) thrusting onto the pedicle screw (3) collar (6). Where it strikes the collar, the head (5) expands in cone shape so the bore (13) makes a fit with this. The screw (3) head (5) has an inside thread for the male lockscrew (18) whose protruding end shoulder seats onto the shoulder (14) of the bore (16).