External fixation strut

Patent metadata

Field	Value
Publication number	US-12491009-B2
Application number	US-202318311081-A
Country	US
Kind code	B2
Filing date	May 2, 2023
Priority date	Mar 23, 2020
Publication date	Dec 9, 2025
Grant date	Dec 9, 2025

Abstract

The present disclosure relates to external fixation struts and systems utilizing the external fixation struts. The struts include an elongated body comprising a first and a second hollow tubular shaft and include opposite connectors respectively coupled to an end portion of the first or the second shaft and each including a ball and socket joint. One shaft may have an internal diameter that is slightly larger than the external diameter than the other shaft to host internally the other shaft in a slidably and telescopic manner. A clamp element may provide a fast gripping action stopping the telescopic sliding of one shaft inside the other shaft. Each ball and socket joint connector may be structured to allow an angular movement of the corresponding connector with a spherical angle up to at least 90°.

First claim

What is claimed is:

1 . An improved external fixation strut comprising:
an elongated body comprising a first hollow tubular shaft and a second hollow tubular shaft; opposite connectors respectively coupled to an end portion of the first shaft and the second shaft and each including a ball and socket joint; one shaft having an internal diameter that is slightly larger than the external diameter of the other shaft to host internally the other shaft in a slidably and telescopic manner; said first and second shafts of the strut being realized by a synthetic radiolucent plastic material; a clamp element provided in proximity of overlapping ends of the first and second shafts for providing a fast gripping action stopping the telescopic sliding of one shaft inside the other shaft; and a manually operated fixation element acting on the clamp element for exerting said fast gripping action; wherein each ball and socket joint connector is structured to allow an angular movement of the corresponding connector with a spherical angle up to at least 90°; the ball and socket joint comprising a socket having at least one radial slot extending from an opening edge of the socket toward a base region thereof, the at least one radial slot being configured to locally enable tilting of the connector up to an angle corresponding to the extension of the radial slot, only one of said at least one radial slots being configured to enable tilting of the connector from alignment with the strut to an angle of at least 90° relative thereto.

2 . The improved external fixation strut of claim 1 comprising:
a sleeve provided around a central portion of the strut where the first and second shafts overlap;
wherein said clamp element is a clamp band and said fixation element is a clamping bolt, the clamp element being around said sleeve and including opposite and facing gripping portions at least one of them having a central threaded hole receiving a threaded shaft of the clamping bolt.

3 . The improved external fixation strut of claim 2 , wherein said clamping bolt has a head coupled to a removable manual butterfly wrench.

4 . The improved external fixation strut of claim 2 , wherein said sleeve is structured with a first sleeve portion having an internal diameter corresponding substantially to the external diameter of the first shaft and a second sleeve portion having an internal diameter corresponding substantially to the external diameter of the second shaft; said clamp band being around said second sleeve portion.

5 . The improved external fixation strut of claim 1 , wherein a dynamization mechanism is associated to one of said opposite connectors, the ball and socket joint of said connector comprising a ball joint, the dynamization mechanism including a first stage associated to one end of a shaft and comprising said ball joint supported by a base portion, a screwed mechanism regulating the projection of the base portion against an internal elastic element and a final stage including a female connector.

6 . The improved external fixation strut of claim 5 , wherein said projecting base portion is axially and slidably coupled to a support element fixed to the shaft end and has an external threaded portion engaged by an adjustment ring abutting against the support element against the elastic action of said internal elastic element.

7 . The improved external fixation strut of claim 6 , wherein said internal elastic element is a spring, the improved external fixation strut comprising an inner shaft fixed at one end to the support element and having a longitudinal slot at the other end, a transversal pin fixed to the base portion and slidable in said longitudinal slot and said spring wrapped around the inner shaft between a fixed end of the inner shaft and the transversal pin.

8 . The improved external fixation strut of claim 7 , wherein said dynamization mechanism includes radiolucent components.

9 . The improved external fixation strut of claim 7 , wherein said final stage is mechanically coupled to the ball joint of the first stage by a rod having one end screwed into the ball joint and an opposite end provided with a female element of the female connector.

10 . The improved external fixation strut of claim 9 , wherein said rod is slidable inside the final stage against the elastic action of a spring-loaded mechanism incorporated in the final stage around the rod.

11 . The improved external fixation strut of claim 1 , wherein one of said opposite connectors is a female connector, wherein a dynamization mechanism for an independent rapid and gradual fine dynamization adjustment in length of the strut is associated to the female connector and includes radiolucent components.

12 . A fixation system including at least a first fixation ring and at least one of a second fixation ring or a fixation arch, the first fixation ring being connected to the at least one of the second fixation ring or the fixation arch by at least two fixation struts wherein said fixation struts comprise:
an elongated body comprising a first hollow tubular shaft and a second hollow tubular shaft; and opposite connectors respectively coupled to an end portion of the first shaft and the second shaft and each including a ball and socket joint, the connectors being fixed to the first and second fixation rings or the fixation arch, each ball and socket joint defining a junction element; one shaft having an internal diameter that is slightly larger than the external diameter of the other shaft to host internally the other shaft in a slidably and telescopic manner; said ball and socket joints allowing an angular movement of the corresponding strut with a spherical angle up to at least 90° for folding the fixation system for packaging and transportation purposes; wherein the fixation system is transitionable between: an operative position, in which the junction elements are substantially straight and the fixation struts are substantially orthogonal to the planes of the fixation rings or arch; and a folded position, in which the junction elements are bent by approximately 90°, resulting in a flattened configuration wherein the fixation struts are substantially parallel to the fixation rings or arch.

13 . The fixation system of claim 12 , wherein a dynamization mechanism including radiolucent components is associated to one of said opposite connectors, the ball and socket joint of said connector comprising a ball joint, the dynamization mechanism including a first stage associated to one end of a shaft and comprising said ball joint supported by a base portion, a screwed mechanism regulating the projection of the base portion against an internal elastic element and a final stage including a female connector.

14 . The fixation system of claim 13 , wherein said projecting base portion is axially and slidably coupled to a support element fixed to the shaft end and has an external threaded portion engaged by an adjustment ring abutting against the support element against the elastic action of said internal elastic element.

15 . The fixation system of claim 12 , comprising:
a sleeve provided around a central portion of the strut where the first and second shaft overlaps; a clamp element provided in proximity of overlapping ends of the first and second shafts for providing a fast gripping action stopping the telescopic sliding of one shaft inside the other shaft; and a manually operated fixation element acting on the clamp element for exerting said fast gripping action; wherein said clamp element is a clamp band and said fixation element is a clamping bolt, said

Assignees

• Orthofix Srl
• Texas Scottish Rite Hospital For Children

Inventors

• Venturini Daniele
• Ottoboni Andrea
• Milano Gianluca
• Ross Jr John D
• Standefer Karen D
• Samchukov Mikhail L
• Cherkashin Alexander M

Classifications

• A61B17/62 Primary

  Ring frames, i.e. devices extending around the bones to be positioned ({A61B17/6433} , A61B17/66 take precedence) · CPC title

• A61B17/66

  {Alignment}, compression or distraction mechanisms · CPC title

• A61B17/6416

  with non-continuous, e.g. hinged, pin-clamp connecting element (A61B17/6425, A61B17/6441 take precedence) · CPC title

• A61B2017/0092

  for X-rays · CPC title

• A61B17/6491

  allowing small-scale motion of bone ends · CPC title