Screw with variable diameter cannulation and driver

摘要

A bone screw driving system includes a screw having a head and a shaft extending from the head. The screw includes a stepped opening extending in the shaft that includes a first portion and a second portion having a greater cross-sectional dimension than the first portion. The bone screw driving system further includes a screw driver having a driver shaft that defines a tip configured to engage the screw head. The driver further includes a pin extending from the tip and sized to fit within the opening. The pin includes an abutment movable to a locked configuration in the second portion of the opening, wherein the abutment defines a cross-sectional dimension greater than that of the first portion of the opening.

主权项

1. A bone fixation screw extending along a longitudinal axis, the bone fixation screw comprising:
a screw head defining a slot configured to engage a driver, the slot defining a slot cross-sectional dimension in a direction transverse to the longitudinal axis, the screw head further defining a proximal end of the bone fixation screw; and a threaded shaft that defines a distal screw tip that is distal to the screw head, the distal screw tip defining a distal end of the bone fixation screw; and the bone fixation screw defining an opening extending longitudinally through the screw head and at least into the threaded shaft, wherein the slot extends from the proximal end and opens directly into a first portion of the opening having a first cross-sectional dimension in a direction transverse to the longitudinal axis, a second portion of the opening having a second cross-sectional dimension in a direction transverse to the longitudinal axis is disposed distal of the first portion, and a transition portion tapers radially outward from the first portion to the second portion, wherein the threaded shaft completely encircles the transition portion along a direction parallel to the longitudinal axis, and wherein the second cross-sectional dimension is greater than the first cross-sectional dimension, and the slot cross-sectional dimension is greater than the first cross-sectional dimension, the second portion is sized to receive a driver abutment that is inserted distally through the first portion into the second portion, and the first cross-sectional dimension is less than a cross-sectional dimension of the driver abutment when the driver abutment is disposed in the second portion.