Bone positioning guide

What is this patent about?

’558 is related to the field of orthopedic surgery and bone realignment, specifically focusing on instruments and techniques for correcting anatomical misalignments in the foot. The background context involves the complexity of manually realigning bones, such as the first metatarsal during a bunion correction or Lapidus procedure, where maintaining precise positioning across multiple planes while fixating the joint is traditionally difficult and prone to inconsistent results.

The underlying idea behind ’558 is to provide a mechanical advantage for multi-planar bone realignment through a specialized guide that applies controlled compression between two different bones. By anchoring one side of the device to a stable anatomical reference—such as the second or third metatarsal—and the other to the misaligned bone, the tool allows a surgeon to precisely reduce the intermetatarsal angle. The inventive insight lies in using a movable shaft and bone engagement member to not only translate the bone but also facilitate rotation, ensuring the deformity is corrected in the transverse, sagittal, and frontal planes simultaneously.

The claims of ’558 focus on a method for correcting a bunion deformity using a bone positioning guide that utilizes a fixation wire to secure the device to the bone being moved. Specifically, the independent claim describes a process where a bone engagement member is placed against the medial side of the first metatarsal, and a wire is driven through a cannulation in that member directly into the bone. This creates a stable mechanical link that allows the mechanism to move the first metatarsal in at least the transverse plane to close the intermetatarsal angle when the engagement member and the tip are urged toward one another.

In practice, the invention works by creating a temporary bridge across the metatarsals. The surgeon positions the tip of the main body against the lateral side of a stable metatarsal and the engagement member against the first metatarsal. By actuating a knob or handle, the threaded shaft advances, pushing the first metatarsal toward the stable reference. Because the engagement member is rotatably coupled to the shaft and pinned to the bone via the K-wire, the device can hold the bone in a corrected, supinated position, allowing the surgeon to perform bone preparation and permanent fixation without the bone slipping back into its deformed state.

This approach differs from prior solutions by moving away from purely manual manipulation or simple two-dimensional clamping. The integration of a cannulated engagement member ensures that the force applied by the guide is directly coupled to the bone's orientation, preventing the tool from sliding along the bone surface during compression. Furthermore, by providing a stable, hands-free hold of the realigned anatomy, the system allows for more accurate bone cuts and better compression across the fusion site, addressing the three-dimensional nature of the deformity rather than just the visible lateral deviation.