Bone positioning and preparing guide systems and methods

What is this patent about?

’873 is related to the field of orthopedic surgery and, more specifically, to instruments and techniques for correcting anatomical misalignments in the foot. The background context involves the surgical treatment of bunion deformities, where the first metatarsal has deviated from its proper orientation relative to the second metatarsal and the medial cuneiform, often requiring complex multi-planar realignment and joint fusion to restore function and alleviate pain.

The underlying idea behind ’873 is that a bunion deformity is a three-dimensional problem that is best addressed by a coordinated mechanical correction rather than isolated bone cuts. The invention recognizes that by applying a controlled force between the first metatarsal and a stable reference point—such as the second metatarsal—a surgeon can simultaneously reduce the intermetatarsal angle and correct the axial rotation of the bone. This approach ensures that the sesamoid bones are returned to their proper weight-bearing position under the metatarsal head while aligning the joint surfaces for successful fusion.

The claims of ’873 focus on a specific surgical workflow for bunion correction that prioritizes the preparation of bone ends before the final realignment. The method involves preparing the facing ends of the first metatarsal and the medial cuneiform at the tarsal-metatarsal joint to create receptive surfaces for fusion. Following this preparation, a bone positioning guide is employed to move the first metatarsal in at least two planes—specifically the frontal and transverse planes—to establish the final corrected position of the bone.

In practice, the system utilizes a C-shaped guide body that bridges the metatarsals, using a threaded actuator to urge a concave bone engagement member toward a stabilized tip. This mechanical advantage allows the surgeon to precisely dial in the correction, rotating the first metatarsal about its long axis while pushing it laterally to close the gap between the first and second metatarsals. A joint spacer and a specialized preparation guide may be used to ensure that the bone cuts are perfectly parallel and properly spaced, facilitating a tight, congruent fit when the joint is compressed for permanent fixation.

This invention differs from prior approaches by integrating the realignment and preparation phases into a repeatable, instrument-guided process that accounts for frontal plane rotation. Traditional methods often relied on freehand bone cuts or simple two-dimensional shifting, which could fail to address the rotational component of the deformity. By using the second metatarsal as a stable anchor for the positioning guide and providing a dedicated guide for parallel bone preparation, the ’873 patent provides a more predictable way to achieve three-dimensional anatomical alignment and stable tarsal-metatarsal fusion.