Surgical procedures that require the insertion of a bone screw often include the use of a wire, such as a “K-wire”, to deliver the bone screw to a desired point of insertion. The K-wire is attached to a bone at a desired point of screw insertion, and extends out of the incision. The bone screw is typically cannulated, meaning the screw has a longitudinal passage extending through the screw that allows the screw to be passed over the K-wire. A cannulated driver tool is also passed over the K-wire and engaged with the screw head to drive the screw into the bone at the desired insertion point.
K-wires can create complications as the bone screw is driven over the K-wire. For example, the K-wire can be inadvertently advanced beyond the anterior margin of the bone and damage vital organs as the screw is driven into the bone. In addition, the K-wire can kink during advancement of the screw over the K-wire. These problems can occur if the trajectory of the screw is not precisely aligned with the trajectory of the K-wire.
Surgeons have used two strategies to avoid or mitigate inadvertent advancement of the K-wire. In the first strategy, the surgeon inserts the K-wire only partly into the bone to provide a margin of error that allows for some inadvertent advancement of the K-wire into the bone. This strategy is problematic because there is a risk that the K-wire will be pulled out during the procedure. In the second strategy, the surgeon uses lateral fluoroscopy to monitor the K-wire throughout the screw insertion process. If K-wire advancement is observed under lateral fluoroscopy, the surgeon halts the procedure until steps are done to prevent further advancement. This strategy is also problematic because it exposes the patient to excessive radiation. Neither strategy prevents or addresses the problem of kinking. Therefore, known methods for driving bone screws over K-wires are prone to complications and are in need of improvement.
USPTO Backgrounds
USPTO Backgrounds