EP-4736793-A2 - CONTOURED BONE PLATE WITH LOCKING SCREW FOR BONE COMPRESSION, PARTICULARLY ACROSS A TARSOMETATARSAL JOINT

Abstract

A method of applying a bone plate across a tarsometatarsal joint or two different portions of a metatarsal may involve positioning a bone plate across a separation between two bone portions. The bone plate can have at least two fixation holes and a bend between the holes. A locking screw can be inserted through one or both holes that has a head thread and a shaft thread, where the shaft thread has a pitch greater than a pitch of the head thread. The locking screw can be screwed into an underlying bone portion until the bend in the bone plate is deformed.

Inventors

• DAYTON, PAUL
• HATCH, DANIEL
• MAY, JASON
• SCANLAN, Sean
• FERGUSON, JOE

Assignees

• Treace Medical Concepts, Inc.

Dates

Publication Date

20260506

Application Date

20220117

Claims (15)

1. An orthopedic fixation system comprising: a bone plate comprising a distal region defining one or more fixation holes, a proximal region defining one or more fixation holes, and an intermediate region between the distal region and the proximal region devoid of fixation holes, the intermediate region comprising a bend; and a locking screw having a head with a head thread and a shaft with a shaft thread, the locking screw having a compression ratio greater than 1.0; wherein the locking screw is configured to be inserted through one of the one or more fixation holes of the distal region and into a first bone portion underlying the distal region and/or one of the one or more fixation holes of the proximal region and into a second bone portion underlying the proximal region, the head thread of the locking screw being configured to engage with threading defined by a fixation hole into which the locking screw is configured to be inserted; and the compression ratio is effective to cause the bone plate to deform the bend.
2. The system of claim 1, wherein the first bone portion and the second bone portion are two different bones separated by a joint between the two different bones.
3. The system of either of claims 2 or 3, wherein at least one of the first bone portion and the second bone portion comprises is a metatarsal.
4. The system of claim 1, wherein the first bone portion and the second bone portion are two portions of a same bone.
5. The system of claim 4, wherein the first bone portion and the second bone portion are two portions of a metatarsal separated by a cut between the two portions.
6. The system of any one of claims 1 to 5, wherein the compression ratio is greater than 1.5, such as greater than 1.7, greater than 1.9, greater than 2.1, or greater than 2.3.
7. The system of any one of the foregoing claims, wherein the bone plate defines a thickness ranging from 1.0 mm to 2 mm.
8. The system of any one of claims 1 to 7, wherein: the locking screw comprises a first locking screw and further comprising a second locking screw; the second locking screw has a head with a head thread and a shaft with a shaft thread, the second locking screw having a compression ratio greater than 1.0; the first locking screw is configured to be inserted through one of the one or more fixation holes of the distal region and into the first bone portion underlying the distal region; and the second locking screw is configured to be inserted through one of the one or more fixation holes of the proximal region and into the second bone portion underlying the proximal region.
9. The system of claim 8, wherein the compression ratio of the second locking screw is greater than 1.5.
10. The system of any one of claims 1 to 7, further comprising at least one other screw configured to be inserted through the one or more fixation holes of the distal region and/or one of the one or more fixation holes of the proximal region not receiving the locking screw, wherein the at least one other screw comprises a non-locking screw and/or another locking screw exhibiting a compression ratio less than that of the locking screw.
11. The system of any one of claims 1 to 10, wherein the distal region has only one fixation hole and the proximal region has only one fixation hole.
12. The system of claim 11, wherein the one fixation hole of the distal region and the one fixation hole of the proximal region are co-axial with each other along a longitudinal axis of the bone plate.
13. The system of any one of claims 1 to 12, wherein the bend is defined by a radius of curvature offsetting the intermediate portion of the bone plate between the one or more fixation holes of the distal region and the one or more holes of the proximal region in a single dimension.
14. The system of any one of claims 1 to 13, wherein the locking screw has a length within a range from 8 mm to 18 mm.
15. The system of any one of claims 1 to 14, wherein the bone plate and the locking screw are included within a sterile container as part of a kit.

Description

RELATED MATTERS This application claims the benefit of US Provisional Patent Application No. 63/138,726, filed January 18, 2021, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD This disclosure relates to bone plates and methods for fixating bones using a bone plate, including compressing opposed bone ends together using a bone plate. BACKGROUND Bones, such as the bones of a foot, may be anatomically misaligned. In certain circumstances, surgical intervention is required to correctly align the bones to reduce patient discomfort and improve patient quality of life. Surgical intervention may involve cutting one or more of the misaligned bones and then physically realigning the bones into an anatomically corrected position. A bone plate or multiple bone plates may be used to hold the bones in the anatomically corrected position, helping to prevent the bones from shifting back to their misaligned position. SUMMARY In general, this disclosure is directed to bone plates and screws, systems incorporating bone plates and screws, and methods of using bone plates. In some examples, bone plate systems and techniques are described to facilitate compression (e.g., angular compression) between opposed ends of two bone portions to which a bone plate is attached, which may be different portions of the same bone or two different bones separated by a joint. The force generated by the plating system may be asymmetrically distributed across the faces of the bone ends being pressed together, e.g., such that there is a greater force on a side of the bone ends opposite the plate than on a side of the bone ends closer to the plate. This may help facilitate angular correction of the bone portions relative to each other and/or promote healing (e.g., fusion) between the bone portions in a corrective orientation. In some implementations, a bone plate includes an elongated body having a length greater than a maximum width and thickness. For example, the bone plate may have a length sized to span a tarsometatarsal joint separating a metatarsal from an opposed cuneiform. The bone plate may include a bend that displaces a portion of the bone plate positionable over the joint between the two bone portions away from the joint. As a result, the bone plate may include a first end contacting one bone portion and a second end contacting the second bone portion, with an intermediate portion between the two ends displaced off of one or both bone portions and/or the joint between the two bone portions. To secure the bone plate to the bone portions, the bone plate can include multiple fixation holes extending through the bone plate, including at least one fixation hole positionable over the first bone portion and at least one additional fixation hole positionable over the second bone portion. One or more of these fixation holes may include threading partially or fully encircling the fixation hole to facilitate engagement with threading on the head of a locking screw insertable through the fixation hole and into an underlying bone. To both secure the locking plate to an underlying bone portion and achieve compression between the ends of the two bone portions being secured together with the bone plate according to some examples, at least one locking screw may be used that is configured to both interlock with the bone plate and deform the bone plate when driven beyond its initially engaged position in the bone plate. For example, as an arch in the bone plate is physically deformed toward a flattened or unbent profile (e.g., resulting in a residual arch of smaller height after deformation), an underside of the plate may be placed in tension and a topside of the plate placed in compression. As a result, a moment force may be applied that has an asymmetrically distributed magnitude across the end faces of the bones being compressed. When used, the locking screw may be configured to interlock with the bone plate and deform the bone plate by controlling the compression ratio of the locking screw. The compression ratio of the bone screw may be controlled by adjusting the pitch of the threading on the head of the screw relative to the pitch of the threading on the shaft of the screw and/or by controlling the lead of the head relative to the lead of the shaft. Traditional bone plate systems utilize one of two different types of screws: compression screws or locking screws. Compression screws are screws that have a threaded shaft but do not have a threaded head. In use, a compression screw can be driven until the head of the screw contacts the bone plate and then further driven into the bone to compress the bone plate. By contrast, locking screws have both a threaded head and a threaded shaft. However, locking screws are generally designed to be screwed until the threaded head is interlocked with the counter threading on the bone plate without causing any compression on the bone plate. In accordance with some examples of the p