Bone Screw System

Abstract

A set of screws sized and configured for fixing a Jones fracture in a fifth metatarsal bone of a patient by preserving a bone thread path. Each screw has a low profile head on a trailing end, a thread portion on a leading portion, and a smooth shank portion between the head portion and the thread portion. A first screw has a thread major diameter of between about 4.4-4.6 mm, a second screw a thread major diameter of between about 5.4-5.6 mm, and a third screw a thread major diameter of between about 6.4-6.6 mm. The thread portion of all the screws in the set has a set of identical thread profile characteristics comprising a pitch, a leading edge angle, a trailing edge angle, a leading edge radius, a trailing edge radius, and a land. Each screw size is provided in various preferred lengths.

1 . A set of screws sized and configured for fixing a Jones fracture in a fifth metatarsal bone of a patient, comprising:
 a set of screws, each said screw having a low profile head on a trailing end, a thread portion on a leading portion, and a smooth shank portion between the head portion and the thread portion,   a first screw of said set of screws having a thread major diameter of between about 4.4 mm to about 4.6 mm,   a second screw of said set of screws having a thread major diameter of between about 5.4 mm to about 5.6 mm,   a third screw of said set of screws having a thread major diameter of between about 6.4 mm to about 6.6 mm, and   said thread portion of all said screws in said set of screws having a set of identical thread profile characteristics, said set of identical thread profile characteristics comprising a pitch, a leading edge angle, a trailing edge angle, a leading edge radius, a trailing edge radius, and a land.   
   
   
       2 . The set of screws of  claim 1 , wherein said first screw has a thread major diameter of about 4.5 mm, said second screw has a thread major diameter of about 5.5 mm, and said third screw has a thread major diameter of about 6.5 mm. 
   
   
       3 . The set of screws of  claim 2 , wherein said first screw has a shank diameter of 3.2 mm, and a thread minor diameter of 3.2 mm,
 said second screw has a shank diameter of 3.5 mm and a thread minor diameter of 3.5 mm, and   said third screw has a shank diameter of 3.8 mm and a thread minor diameter of 3.8 mm.   
   
   
       4 . The set of screws of  claim 1 , wherein said identical thread profile characteristics comprises said pitch is between about 2 to about 2.5 mm; said leading edge angle is between about 60 to about 70 degrees; said trailing edge angle is between about 90 to about 100 degrees; said leading edge radius is about 0.8 mm; said trailing edge radius is about 0.3 mm; and said land is about 0.18 mm. 
   
   
       5 . The set of screws of  claim 4 , wherein said pitch is about 2.2 mm, said leading edge angle is about 65 degrees, and said trailing edge angle is about 95 degrees. 
   
   
       6 . The set of screws of  claim 4 , wherein said leading edge of said thread has a surface that is substantially flat except in a region of said leading edge radius, and said trailing edge of said thread has a surface that is substantially flat except in a region of said trailing edge radius. 
   
   
       7 . The set of screws of  claim 1 , wherein said thread of said screws is a sharp cancellous thread form. 
   
   
       8 . The set of screws of  claim 7 , wherein said sharp cancellous thread form is an HB type bone screw thread under ASTM F543-02 and ISO 5835 standards. 
   
   
       9 . The set of screws of  claim 1 , wherein each of said first, second and third screws is provided in a plurality of screw lengths for use in fixing fractures in a variety of fifth metatarsal bones, said screw lengths being 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm and 70 mm. 
   
   
       10 . The set of screws of  claim 9 , wherein each said thread portion has a thread portion length of between about 12.7 mm to about 25.4 mm. 
   
   
       11 . The set of screws of  claim 10 , wherein said thread portion length is about 14 mm for each said screw having a screw length of 40 mm,
 said thread portion length is about 15.7 mm for each said screw having a screw length of 45 mm,   said thread portion length is about 15.5 mm for each said screw having a screw length of 50 mm,   said thread portion length is about 19.3 mm for each said screw having a screw length of 55 mm,   said thread portion length is about 21.1 mm for each said screw having a screw length of 60 mm,   said thread portion length is about 22.9 mm for each said screw having a screw length of 65 mm, and   said thread portion length is about 24.6 mm for each said screw having a screw length of 70 mm.   
   
   
       12 . The set of screws of  claim 1 , wherein said low-profile head of each said screw has a generally hemi-spherical configuration, with a generally flat trailing end and a generally spherical leading edge. 
   
   
       13 . The set of screws of  claim 12 , wherein a radius of said spherical leading edge substantially matches a radius of said low profile head and originates along a lengthwise axis of said screw between about 0 mm to about 0.76 mm from said trailing end of said head. 
   
   
       14 . The set of screws of  claim 12 , wherein said low-profile head has an outer diameter of between about 7.0 mm to about 9.0 mm. 
   
   
       15 . The set of screws of  claim 14 , wherein said low-profile head of said first screw has an outer diameter of about 7.2 mm and a leading edge radius of about 3.4 mm,
 said low-profile head of said second screw has an outer diameter of about 7.4 mm and a leading edge radius of about 3.7 mm, and   said low-profile head of said third screw has an outer diameter of about 8.1 mm and a leading edge radius of about 4.1 mm.   
   
   
       16 . The set of screws of  claim 1 , wherein a trailing end of said thread has reverse cutting flutes configured for use in cutting bone during removal of the screw, to thereby assist with removal of said screws from the patient after bone in-growth has occurred. 
   
   
       17 . The set of screws of  claim 1 , wherein at least one of said screws consists of surgical grade stainless steel and is solid. 
   
   
       18 . The set of screws of  claim 1 , wherein at least one of said screws consists of titanium and is solid. 
   
   
       19 - 37 . (canceled)