External bone fixation system
View Patent ↗An external fixation assembly for bone fusion or separation is disclosed. The assembly includes a fracture fusion tube, with a bracket slidably engaged thereon. The assembly further includes a collet clamp connected to the bracket, with a ball collet rotatably seated within the clamp, the ball collet having an aperture for receiving a bone bin therethrough and perforations for a compression engagement with a bone pin. The assembly uses a single screw for threadably engaging the ball collet, the clamp and the bracket such that the position of the bone pin, ball collet and bracket are all fixed.
1. An external bone fixation system for attaching to multiple bone pins, the system comprising:
a fracture fusion tube having at least one of a recess or a detent disposed along a length of the fracture fusion tube; and
multiple bracket/clamp assemblies removably attached to the fracture fusion tube, wherein each of the bracket/clamp assemblies comprises:
a bracket slideably attached to the fracture fusion tube, the bracket having a structure that includes a threaded bracket support aperture and a bracket throughbore;
a pin collet clamp fixed to, and independently rotatable relative to, the bracket, the pin collet clamp including a threaded clamp support aperture and a clamp throughbore;
a sleeve disposed in the clamp throughbore;
a ball collet rotatably disposed within the sleeve, and defining an aperture for receiving one of the multiple bone pins therethrough, the direction of the aperture being independently adjustable across multiple planes relative to the bracket and the pin collet clamp; and
a single screw for threadably engaging the pin collet clamp and the bracket via the clamp support aperture and the bracket support aperture
wherein tightening the single screw within the clamp support aperture and the bracket support aperture simultaneously tightens the bracket in its attachment to the fracture fusion tube, tightens the bracket and clamp together so that they cannot rotate relative to one another, and compresses the clamp throughbore, which thus crushes the ball collet, thus preventing the ball collet from rotating within the sleeve and tightening an attachment of the aperture of the ball collet over the one bone pin, and
wherein the at least one recess or detent is disposed along the fracture fusion tube between at least two of the multiple bracket/clamp assemblies, and wherein the at least one recess or detent prevents the bracket/clamp assemblies from sliding past the at least one recess or detent along the fracture fusion tube.
2. The system of claim 1 , wherein the sleeve comprises a separate piece inserted into the clamp throughbore of the pin collet clamp.
3. The system of claim 1 , wherein the pin collet clamp comprises a first surface feature on a side of the pin collet clamp, and wherein the bracket comprises a second surface feature on a side of the bracket, wherein the first surface feature and the second feature are configured to mate with one another when the side of the pin collet clamp and the side of the bracket are brought together by tightening the single screw.
4. The system of claim 1 , wherein the fracture fusion tube is cylindrical.
5. The system of claim 1 , wherein the fraction fusion tube has a constant outside diameter, except at the at least one recess or detent.
6. The system of claim 1 , wherein the ball collet comprises:
a first pair of cuts extending from a first opening of the ball collet aperture over an outer surface of the ball collet toward a second opening of the ball collet aperture; and
a second pair of cuts extending from the second opening of the ball collet aperture over the outer surface of the ball collet toward the first opening of the ball collet aperture,
wherein each of the first and second pairs of cuts extends along approximately 90 percent of a length of the outer surface, and
wherein the cuts are configured to allow the ball collet to collapse when squeezed within the clamp throughbore of the pin collet clamp.