Quick attachment clamp for external fixation systems

Patent metadata

Field	Value
Publication number	US-2020367935-A1
Application number	US-201816969824-A
Country	US
Kind code	A1
Filing date	Dec 20, 2018
Priority date	Feb 16, 2018
Publication date	Nov 26, 2020
Grant date	—

Abstract

Clamp (1) for an external fixator, preferably of the quick attachment type, comprising: a plurality of attachments (2; 3) for blocking bars and/or bone screws; a connector (5), provided with an at least partially threaded stem (50), which passes through and connects in series said plurality of attachments (2; 3); at least one first attachment (2) comprising two arms (20; 21), connected by a C-shaped flexible bridge (22); said stem (50) passing through said first attachment (2) in an intermediate position between said flexible bridge (22) and the opposite free ends of said arms (20; 21); wherein, at the free ends, said arms (20; 21) define a screw housing seat (23) for a bone screw, said screw housing seat being selectively configurable, varying the deformation of the flexible bridge (22), to clamp bone screws having different diameter.

First claim

1 . Clamp ( 1 ) for an external fixator ( 100 ), comprising: a plurality of attachments ( 2 ; 3 ; 4 ) for locking bars ( 101 ) and/or bone screws ( 102 ); a connector ( 5 ) provided with an at least partially threaded stem ( 50 ), which passes through and connects in series said plurality of attachments ( 2 ; 3 ; 4 ); at least one first attachment ( 2 ) of said plurality of attachments ( 2 ; 3 ; 4 ) comprising two arms ( 20 ; 21 ), connected by a C-shaped flexible bridge ( 22 ); said stem ( 50 ) passing through said first attachment ( 2 ) in an intermediate position between said flexible bridge ( 22 ) and the opposite free ends of said arms ( 20 ; 21 ) characterized in that, at the free ends, said arms ( 20 ; 21 ) define a screw housing seat ( 23 ) for a bone screw ( 102 ), said screw housing seat ( 23 ) being selectively configurable, varying the deformation of the flexible bridge ( 22 ), to clamp bone screws ( 102 ) having different diameter.

2 . Clamp ( 1 ) according to claim 1 , wherein said screw housing seat ( 23 ) allows at least the clamping of bone screws ( 102 ) with diameters of 4 mm, 5 mm and 6 mm.

3 . Clamp ( 1 ) according to one of the preceding claims, wherein at least one of said arms ( 20 ; 21 ) of the first attachment ( 2 ) has an enlarged hole ( 24 ) substantially wider with respect to the stem ( 50 ) that passes through it, so that it does not interfere with said stem as the deformation of the flexible bridge ( 22 ) varies, at least in the range which corresponds to the desired variability for the diameter of the bone screws ( 102 ) that can be clamped within said housing seat ( 23 ).

4 . Clamp ( 1 ) according to claim 3 , wherein the arm of the first attachment ( 2 ) that has the enlarged hole ( 24 ) is an inner arm ( 20 ) with respect to the overall structure of the clamp ( 1 ), namely it is the arm juxtaposed to a second attachment ( 3 ).

5 . Clamp ( 1 ) according to claim 4 , wherein the external arm ( 21 ) of said first attachment ( 2 ) has a passage hole ( 25 ) for said stem ( 50 ); said connector ( 5 ) comprises a head ( 51 ) integral with the stem ( 50 ) and joined thereto with a concave surface ( 52 ); said external arm ( 21 ) provides, at the outlet of said passage hole ( 25 ), for a convex seat ( 28 ) adapted to contactingly match said concave surface ( 52 ) even when the external arm ( 21 ) is bent with respect to a condition of perpendicularity to the stem ( 50 ).

6 . Clamp ( 1 ) according to one of the preceding claims, wherein said screw housing seat ( 23 ) is defined by specular V-shaped profiles, which are facing and opposite one another, of respective jaws ( 27 a ; 27 b ) integral with the free ends of the arms ( 20 ; 21 ) of the first attachment ( 2 ).

7 . Clamp ( 1 ) according to one of the preceding claims, wherein said first attachment ( 2 ) also provides for a bar housing seat ( 26 ) for a bar ( 101 ) of the external fixator ( 100 ).

8 . Clamp ( 1 ) according to claim 7 , wherein said bar housing seat ( 26 ) is defined by an inner profile, substantially shaped as an arc of a circle, of the flexible bridge ( 22 ) of the first attachment ( 2 ), said arc of a circle subtending an angle greater than 180°.

9 . Clamp ( 1 ) according to one of the preceding claims, wherein said connector ( 5 ) provides, at an end of the stem ( 50 ), for a coupling profile ( 53 ) for a tightening tool and a tightening knob ( 54 ), with a diameter substantially greater with respect to said coupling profile ( 52 ), for the manual tightening of the connector ( 5 ).

10 . Clamp ( 1 ) according to claim 9 , wherein said tightening knob ( 54 ) has means to facilitate the manual gripping thereof, such as knurling or surface coating.

11 . Clamp ( 1 ) according to one of the preceding claims, further comprising a second attachment ( 3 ) provided with a bar housing seat ( 36 ) or a third attachment ( 4 ) provided with one or more screw housing seats ( 42 ; 43 ).

Assignees

• Orthofix Srl

Inventors

• Venturini Daniele
• Zandona Enrico
• Dal Zovo Chiara

Classifications

• A61B17/6466 Primary

  with pin-clamps movable along a solid connecting rod · CPC title

• A61B17/6475 Primary

  the connecting rod being threaded · CPC title