DISTRACTOR MECHANISM FOR EXTERNAL FIXATION DEVICE

摘要

A distraction apparatus (100a-100d, 200, 300) for an external fixation device used to rigidly immobilize bone fragments during bone lengthening and angular deformity correction includes distractor mechanisms (102, 202) and pivotal spacers (204, 304) for connecting frame members (106, 108) of an external fixator, and wire and pin fasteners (112a-112c). The interconnected distractor mechanisms (102, 202), pivotable spacers (204, 304) and frame members (106, 108) form a rigid structure with rigidity which is maintained during adjustment of the distraction. For linear distraction, the distraction mechanism is one of a single screw assembly (102b) or one of three-type of telescoping screw assemblies (102a, 102c, 102d). For angular distraction, the distraction mechanism includes an angular distractor (202) with a rotatable knob (218) and pivotable spacers (204, 304) which are connected to the frame members (106, 108). For wire and pin fixation to the frame members (106, 108), the fastener assembly includes a fixation bolt (112a-112c) with either a transverse asymmetrical shank bore (113e), or a transversely slotted (115e) bolt head.