A Bone Clip That Pushes Against Its Own Screws Sharing the Squeeze Across a Fusion Site

This application covers a fixation system for holding two pieces of bone together while they heal, built from a springy metal clip and at least one screw placed at an angle to the clip’s legs. It was filed by Crossroads Extremity Systems, LLC and names Michael Campbell, Daniel Sayger and Michael Hollis as inventors. It is a divisional of Australian application 2021233809. The title and abstract describe a general “small bone fixation” family, and the claims narrow that to a clip with no screw holes in its bridge, a screw that sits clear of the bridge, and the guides used to drill for them.

The Problem

Bones that have to knit together, whether after a fracture, a cut made to correct alignment, or a deliberate arthrodesis that fuses a joint, heal better when the two surfaces are held under some steady pressure. The background puts it plainly: tiny movements at the gap between the pieces slow healing, and compressing the pieces together reduces those movements.

The specification is aimed at small bones, and the abstract names the foot and hand. A small bone leaves little room for hardware. The description notes that the amount of cortical bone available for a compression screw at the break line can be very limited, and that a clip whose legs end in soft cancellous bone can lose some of its grip if that spongy bone gives way under the force from the legs. A clip alone squeezes, but it squeezes through the weakest part of the bone.

What This Invention Does

Claim 1 is a bone fixation system for implanting across a break or across a joint between two bones. It has two parts. The first is an elongate implant, which in the dependent claims is a screw. The second is a clip with a first leg, a second leg and a bridge joining them at one end. When the clip is deformed, the bridge flexes elastically and the free ends of the legs move apart. Released, the legs spring back toward each other. One leg goes in on each side of the break.

The claim then pins down what makes this version different. The clip is “devoid of screw holes that extend through the bridge”. That sets it apart from a staple plate, where screws pass through the bridge itself. Here the screw goes in beside the clip, on one side of the break, entirely spaced from the bridge at a location between the legs, and the first leg contacts the screw.

Claim 19 states the same idea as a construct of a bone screw and a clip. The bridge and legs define a plane, the screw is oriented at an angle to that plane, and one leg touches the screw so that the leg urges the screw toward the other leg. The mechanism the description gives is that the squeeze from the legs, which end in cancellous bone, is passed to the angled screws. Those screws are long enough for bicortical purchase, meaning they grip the hard outer shell of the bone on both faces. The description says this transfers the fixation force from the clip legs to the stronger cortical bone and preserves the compression the clip provides.

The rest of the claims cover the instruments. Claim 9 is a drill guide with one pair of locating holes for the clip legs and a second, closer-spaced pair for the screws or guide wires, on opposite sides of the break. Claim 14 is a two-part surgical guide system, a clip drill guide with a cannula on each side of the break plus an implant guide with positioning holes. Claim 18 makes the implant guide arc shaped, with holes at varying angles.

The specification contains no test results. There are no cadaver, bench or clinical figures, so the claimed benefits (stronger fixation, faster recovery) are stated as aims rather than measured. The numbers it does give are small: the screw may sit anywhere from touching the leg to about a 2 mm gap away from it.

Key Features

• A clip with no holes in the bridge. The bridge is a plain elastic link between two legs. Screws are not driven through it, so the screw position is chosen separately from the clip position.
• Legs that finish in cancellous bone. Claim 2 sets the leg length so the free ends end in the spongy interior of the bone, where the legs can spring toward each other and compress the break.
• Screws at an angle to the clip. In claim 5 the bridge and legs define a plane and the screws are driven along a direction offset from it. The screws and legs cross when viewed from the side, which is how the load is handed across.
• Bicortical screws. Claim 3 specifies a screw long enough to achieve bicortical purchase. Claims 6 to 8 allow fully threaded or partly threaded screws, and non-cannulated screws.
• Materials left open. The description lists titanium, stainless steel, PEEK and nitinol for the clip, and says shape memory material may be used. Teeth on the inside faces of the legs are described as improving grip and pull-out resistance.
• Guides for repeatable placement. The drill guide and implant guide set the spacing between the clip holes and the screw holes, and are designed to guide drilling or wire placement without crossing the break line.

Who Is Behind It

The applicant is Crossroads Extremity Systems, LLC, a Memphis, Tennessee company founded in 2014 by three medical device engineers to make sterile-packed implants and instruments for foot and ankle surgery. Orthopedics This Week reported in February 2022 that the company had been sold to DePuy Synthes, a Johnson & Johnson company, with terms not disclosed, and listed a staple compression plate among its products. Its private equity backer Healthpoint Capital, which invested in May 2019, records the February 2022 sale on its portfolio page. The application still names Crossroads Extremity Systems, LLC as the applicant, and this specification does not say who owns the family today.

On priority, the specification states one source: a paragraph at the head of the body says the application claims the benefit of U.S. Provisional Application No. 62/987,299, filed 9 March 2020. The title page records the application as a divisional of Australian application 2021233809. The specification itself does not say whether 2021233809 entered Australia from an international application, and this article does not go beyond what the document states.

Why It Matters

Staples that squeeze and screws that hold are both established ways of fusing small bones, and each has a known weakness. A staple relies on the grip of its legs in soft bone. A single screw gives rigid hold but little continuous squeeze unless it is a compression screw, and there may be no room for one. This claim joins the two by making the screws a backstop for the clip, so the clip’s spring force keeps working through harder bone.

The choice to leave out holes in the bridge also has a practical effect. The surgeon can place screws wherever the bone is best, not where a plate puts the holes, and the guides in claims 9 and 14 turn that freedom into a repeatable drilling pattern. Whether the combination performs better than existing staple plates is not shown in this document, so the case for it rests on the mechanism described.

Related Concepts

• Internal fixation – the general surgical approach of holding bone pieces together with implants placed inside the body.
• Bone screw – the angled screw that takes the clip’s load in the claimed system.
• Shape-memory alloy – the class of metals, including nitinol, that the description suggests for a clip that springs back after being opened.
• Bone healing – the biological process that steady compression across a gap is meant to support.
• Nitinol – the nickel titanium alloy named as a possible clip material.
• Osteotomy – the deliberate cut in a bone, one of the cases where two bone portions must be fixed together.

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AU 2026202274 was published in the Australian Official Journal of Patents on 9 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.