Orthopedic bone staple with polyaxial compression capability

Abstract

A bone fixation device or bone staple includes a crown portion, an engagement portion, and an outer rim generally defined between the crown portion and the engagement portion. The engagement portion includes a plurality of legs extending from the outer rim in a direction away from the crown portion. The plurality of legs are generally radially disposed and evenly spaced apart around the outer rim. The legs are beveled to provide a compressive effect to the bone when the staple is inserted into the bone.

What is claimed is: 
     
         1 . A bone staple comprising:
 a crown portion comprising a generally circular body defining an outer rim; and   a plurality of legs extending from the crown portion and spaced circumferentially about the outer rim, each of the plurality of legs defining an inner surface directed inwardly toward a central axis, a pointed tip, and at least one inwardly-directed and obliquely-inclined bevel extending between the inner surface and the pointed tip;   whereby the inwardly-directed and obliquely-inclined bevels impart a diverging directional force on the plurality of legs upon insertion of the staple into bone to effect compression of the bone between the plurality of legs.   
     
     
         2 . The bone staple of  claim 1 , wherein the inwardly-directed and obliquely-inclined bevels each comprise a pair of angularly offset faceted bevels with an edge defined between the angularly offset faceted bevels. 
     
     
         3 . The bone staple of  claim 1 , wherein each of the plurality of legs further comprises a non-beveled outer surface opposite the inner surface. 
     
     
         4 . The bone staple of  claim 1 , wherein the crown portion comprises a central opening. 
     
     
         5 . The bone staple of  claim 4 , wherein the crown portion comprises at least one peripheral opening spaced from the central opening. 
     
     
         6 . The bone staple of  claim 1 , wherein at least one of the plurality of legs comprises a first length and at least another one of the plurality of legs comprises a different second length. 
     
     
         7 . The bone staple of  claim 6 , wherein the first and second lengths of the legs comprise a ratio L 1 :L 2  of about 2:1. 
     
     
         8 . The bone staple of  claim 6 , wherein the plurality of legs comprises an alternating array of longer and shorter legs. 
     
     
         9 . The bone staple of  claim 1 , wherein the plurality of legs are evenly spaced about the outer rim of the crown portion to effect a symmetric poly-axial compression of the bone between the plurality of legs upon insertion of the staple into bone. 
     
     
         10 . A bone staple comprising:
 a crown portion comprising an outer periphery; and   a plurality of legs extending from the crown portion and spaced about the outer periphery, each of the plurality of legs defining an inwardly directed surface, a pointed tip, and at least one obliquely-inclined bevel extending between the inwardly directed surface and the pointed tip, wherein at least one of the plurality of legs comprises a first length and at least another one of the plurality of legs comprises a different second length;   whereby the obliquely-inclined bevels impart a diverging directional force on the plurality of legs upon insertion of the staple into bone to effect compression of the bone between the plurality of legs.   
     
     
         11 . The bone staple of  claim 10 , wherein the crown portion comprises a generally circular body, and wherein the plurality of legs are spaced circumferentially about the outer periphery. 
     
     
         12 . The bone staple of  claim 10 , wherein the obliquely-inclined bevels each comprise a pair of angularly offset faceted bevels with an edge defined therebetween. 
     
     
         13 . The bone staple of  claim 10 , wherein each of the plurality of legs further comprises a non-beveled outwardly directed surface opposite the inwardly directed surface. 
     
     
         14 . The bone staple of  claim 10 , wherein the crown portion comprises a central opening. 
     
     
         15 . The bone staple of  claim 14 , wherein the crown portion comprises at least one peripheral opening spaced from the central opening. 
     
     
         16 . The bone staple of  claim 10 , wherein the first and second lengths of the legs comprise a ratio L 1 :L 2  of about 2:1. 
     
     
         17 . The bone staple of  claim 10 , wherein the plurality of legs comprises an alternating array of longer and shorter legs. 
     
     
         18 . The bone staple of  claim 10 , wherein the plurality of legs are evenly spaced about the outer periphery of the crown portion to effect a symmetric poly-axial compression of the bone between the plurality of legs upon insertion of the staple into bone. 
     
     
         19 . A bone staple comprising:
 a crown portion comprising a generally circular body defining an outer rim; and   a plurality of legs extending from the crown portion and spaced circumferentially about the outer rim, each of the plurality of legs defining an inner surface, a pointed tip, and at least one bevel extending between the inner surface and the pointed tip, wherein at least one of the plurality of legs comprises a first length and at least another one of the plurality of legs comprises a different second length;   whereby the bevels impart a diverging directional force on the plurality of legs upon insertion of the staple into bone to effect compression of the bone between the plurality of legs.   
     
     
         20 . The bone staple of  claim 19 , wherein the at least one bevel of each of the plurality of legs comprises an inwardly-directed and obliquely-inclined bevel. 
     
     
         21 . The bone staple of  claim 19 , wherein the at least one bevel of each of the plurality of legs comprises a pair of angularly offset faceted bevels with an edge defined therebetween. 
     
     
         22 . The bone staple of  claim 19 , wherein each of the plurality of legs further comprises a non-beveled outer surface opposite the inner surface. 
     
     
         23 . The bone staple of  claim 19 , wherein the crown portion comprises a central opening. 
     
     
         24 . The bone staple of  claim 23 , wherein the crown portion comprises at least one peripheral opening spaced from the central opening. 
     
     
         25 . The bone staple of  claim 19 , wherein the first and second lengths of the legs comprise a ratio L 1 :L 2  of about 2:1. 
     
     
         26 . The bone staple of  claim 19 , wherein the plurality of legs comprises an alternating array of longer and shorter legs. 
     
     
         27 . The bone staple of  claim 19 , wherein the plurality of legs are evenly spaced about the outer rim of the crown portion to effect a symmetric poly-axial compression of the bone between the plurality of legs upon insertion of the staple into bone. 
     
     
         28 . A method of applying compression to a bone substrate, the method comprising:
 providing a bone staple comprising a crown portion and a plurality of legs extending from the crown portion, wherein each of the plurality of legs comprise an inner surface, a pointed tip, and at least one obliquely inclined bevel extending between the inner surface and the pointed tip, wherein at least one of the plurality of legs comprises a first length and at least another one of the plurality of legs comprises a different second length; and   inserting the staple into the bone substrate, whereby the obliquely inclined bevels impart a diverging directional force on the plurality of legs to effect compression of the bone substrate between the plurality of legs.