Cross pin fixator for bone fragments and use thereof

Abstract

The present application relates to a cross pin fixator device comprising a plate member with spherical cavities that are open to the front and to the back of the plate, collapsible pin holder members having a central channel for insertion of a bone pin, the collapsible pin holder member being press-fit into the spherical cavities, and bone pins individually inserted into the central channel of a pin holder. The application also relates to a method for treating a fracture of the proximal humerus using the proximal humerus cross pin fixator and to a kit for treating a fracture of a bone.

1 . A cross pin fixator device comprising:
 a plate member having a plurality of spherical cavities that are open to the front and to the back of the plate;   a plurality of collapsible pin holder members having a central channel for insertion of a bone pin, wherein each collapsible pin holder member is press-fit into one of the spherical cavities, wherein at least one of the plurality of collapsible pin holders is configured to freely rotate inside a spherical cavity; and   threaded holes in the plate comprising set screws that contact the collapsible pin holder members from the side and immobilize or deform the pin holder members in the cavities.   
     
     
         2 . The cross pin fixator device of  claim 1 , wherein the device is a proximal humerus cross pin fixator. 
     
     
         3 . The cross pin fixator device of  claim 1 , wherein the pin holders are retained in the plate by ridges in the plate. 
     
     
         4 . The cross pin fixator device of  claim 1 , wherein the plate is constituted of a lightweight material. 
     
     
         5 . The cross pin fixator device of  claim 4 , wherein the lightweight material is selected from the group consisting of aluminum, aluminum alloy, titanium, titanium alloy and a fiber reinforced polymeric material. 
     
     
         6 . The cross pin fixator device of  claim 5 , wherein the polymeric material is selected from the group consisting of PPS (polyphenylene sulfide), PEEK (polyetherether ketone), Ultrapek (polyether ketone ether ketone), epoxy, polyester, polyamide, and vinyl ester. 
     
     
         7 . The cross pin fixator device of  claim 5 , wherein the fiber is selected from the group consisting of carbon fibers, glass fibers, metal fibers, synthetic fibers, and mixtures thereof. 
     
     
         8 . The cross pin fixator device of  claim 5 , wherein the fiber reinforced polymeric material comprises carbon-fiber reinforced plastic. 
     
     
         9 . The cross pin fixator device of  claim 1 , wherein the plate is constituted of a high strength material. 
     
     
         10 . The cross pin fixator device of  claim 9 , wherein the high strength material is mineral reinforced plastic. 
     
     
         11 . The cross pin fixator device of  claim 10 , wherein the mineral is selected from the group consisting of talc, silica, silicon carbide, zirconia and alumina. 
     
     
         12 . The cross pin fixator device of  claim 9 , wherein the high strength material is a ceramic material. 
     
     
         13 . The cross pin fixator device of  claim 12 , wherein the ceramic material is selected from the group consisting of alumina, zirconia, and silicon carbide. 
     
     
         14 . The cross pin fixator device of  claim 9 , wherein the high strength material is steel or steel alloys. 
     
     
         15 - 17 . (canceled) 
     
     
         18 . A method for treating a fracture of a proximal humerus in a patient comprising:
 inserting one end of each of a plurality of bone pins through the fracture site, wherein the bone pins traverse the site of the bone fracture in a multi-angle and multi-planar configuration so as to secure fractured bone segments against rotation and axial movement, and   inserting the opposite end of each of the plurality of bone pins through a collapsible pin holder member of a proximal humerus cross pin fixator having a central channel for insertion of a bone pin, wherein each collapsible pin holder member is press-fit into a spherical cavity of a plate member of the proximal humerus cross pin fixator and wherein at least one of the plurality of collapsible pin holders is configured to freely rotate inside a spherical cavity.   
     
     
         19 . The method of  claim 18 , wherein each bone pin is a Kirschner wire. 
     
     
         20 . The method of  claim 18 , further comprising immobilizing or deforming a collapsible pin holder by tightening a set screw inserted into a threaded hole in the plate member of the proximal humerus cross pin fixator. 
     
     
         21 . A kit for the treatment of a fracture of a bone, comprising:
 the cross pin fixator device of  claim 1 , and   a plurality of bone pins.   
     
     
         22 . The kit of  claim 21 , wherein the bone pins are Kirschner wires.