Abstract:
A bone plate system for the internal fixation of metacarpal and phalanx fractures of the hand is provided. The plates are structured to permit independent reconfiguration of holes of the plates relative to a longitudinal axis and are configured to orient fasteners to interdigitate with holes displaced along the longitudinal axis. The plates are very thin, and a locking screw with a low profile head design is provided for use therewith.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates broadly to surgical devices and methods for the internal fixation of fractured bones, and more particularly, to bone plates and fasteners. 
     2. State of the Art 
     Metacarpal fractures are the most common fracture affecting the hand, accounting for about 48% of hand injuries and 12% of all types of fractures. Phalangeal fractures account for about 40% of hand injuries and 10% of all fractures. Displaced metacarpal and phalangeal fractures should be treated with open reduction and internal fixation with screws and very small bone plates. 
     Bone plate systems for hand fractures are currently available in the small sizes required for placement on metacarpal and phalangeal bones. For example, the Stryker Profyle Small Bone Plating System is specifically designed for fractures of the metacarpal and phalangeal bones. The system includes a set of small plates in several shapes includes straight, T-shaped, L-shaped, and ladder configuration with parallel rails and rungs extending across the rails connecting the locations of various fixation holes. By way of another example, the Synthes Compact Hand system includes straight, T-shaped, and Y-shaped plates for the fixation of fractures of the hand. The plates in the system can be bent in an attempt to approximate the contour of the bone. In order to bend a plate, a pair of pliers are used on opposing sides of the portion intended to be bent, or two rods are threadably coupled directly into a limited number of round threaded holes in the plate and force is applied to the rods to bend the plate. In either method, the plate is bent off the bone through trial and error. In addition, the plates may be trimmed to length and then subsequently deburred, also while off the bone to permit the cutting pliers proper access to the plate. 
     SUMMARY OF THE INVENTION 
     A bone plate system for the internal fixation of small bones, such as metacarpal and phalangeal bones of the hand, is provided. Each plate includes a straight rail with a longitudinal axis. The rail includes a linear arrangement of ring-shaped screw hole boundaries, with adjacent boundaries interconnected by a web having a width and a thickness. Each boundary defines a screw hole for receiving a screw. Each screw hole may be any one of a locking screw hole, a non-locking screw hole, and an elongated hole. In various embodiments one or more extensions extends non-axially from the rail. The extensions each include one or more screw hole boundaries, each boundary including a screw hole and linearly connected to the rail or another boundary by a web. 
     Preferred shapes for plates of the system, to accommodate the bones of the hand, include a straight plate, a T-shaped plate, a Y-shaped plate, a plate having a Y-shape at one end and a T-shape at its opposite end (a TY-shaped plate), and a ‘web’ plate having one or more extensions, each extension with one screw hole boundary and extending from the location of a hole in the rail of the plate. The arms of the Y-shaped plate and TY-shaped plate form a net or cage along the shaft of a bone for high energy or segmental bone loss applications. This can be accomplished by bringing in the extensions along the bone shaft and leaving them unfilled. In addition, the extensions of the web plate are staggered such that the trajectories of the axes of the holes in the extensions do not intersect the trajectories of the axes of the holes in the rail. 
     The plates are reconfigurable in shape, even while the plate is located on the bone. The plates are preferably provided pre-assembled with guides at any one of, and preferably each of, the threaded holes. Plate shaping tools may be attached to the guides and/or plate while the plate is located on the bone to effect alteration of the plate shape in an effective and precise manner. In addition, the guides can be used to aid drilling holes for fasteners to couple the plate to bone. The tools are designed such that a drill and K-wires can be inserted through the guides while the tools are coupled to the guides. Further, the plate shaping tools at the guides and/or pliers directly on the plate can be used to repeatedly stress a web location and purposefully cause a clean break to alter the size and/or shape of a plate to better accommodate the anatomy. 
     The boundaries of the plates surrounding the screw holes are very thin, and a small locking screw with a low profile head design is provided for use therewith. The locking screw has a socket with a flat bottom recess that optimizes the material thickness between the socket and a lower surface of the head to provide sufficient driver engagement without reducing the torsional strength of the head to shank attachment relative to screws designed for larger plates. 
     Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a straight plate according to the system of the invention. 
         FIG. 2  is a side elevation of the straight plate of  FIG. 1 . 
         FIG. 3  is an isometric view of the straight plate of  FIG. 1 , shown with guides preassembled within the locking screw holes of the plate. 
         FIG. 4  is an isometric view of a guide for use in the system of the invention. 
         FIG. 5  is a side elevation of a T-shaped plate according to the system of the invention. 
         FIG. 6  is an isometric view of the T-shaped plate of  FIG. 5 . 
         FIG. 7  is an end view of the T-shaped plate of  FIG. 5 . 
         FIG. 8  is a view similar to  FIG. 6 , shown with guides pre-assembled within the locking screw holes of the plate. 
         FIG. 9  is a side elevation of a Y-shaped plate according to the system of the invention. 
         FIG. 10  is an isometric view of the Y-shaped plate of  FIG. 9 . 
         FIG. 11  is an end view of the Y-shaped plate of  FIG. 9 . 
         FIG. 12  is a view similar to  FIG. 9 , shown with guides pre-assembled within the locking screw holes of the plate. 
         FIG. 13  is a side elevation of a TY-shaped plate according to the system of the invention. 
         FIG. 14  is an isometric view of the TY-shaped plate of  FIG. 13 . 
         FIG. 15  is a first end view of the TY-shaped plate of  FIG. 13 . 
         FIG. 16  is a second end view of the TY-shaped plate of  FIG. 13 . 
         FIG. 17  is a view similar to  FIG. 13 , shown with guides pre-assembled within the locking screw holes of the plate. 
         FIG. 18  is a side elevation of a web plate according to the system of the invention. 
         FIG. 19  is a plan view of the web plate of  FIG. 18 . 
         FIG. 20  is an isometric view of the web plate of  FIG. 18 . 
         FIG. 21  is an end view of the web plate of  FIG. 18 . 
         FIG. 22  is a plan view of an alternate web plate, shown with guides pre-assembled within the locking screw holes of the plate. 
         FIG. 23  is a side elevation of a bending tool for manipulating a plate via the guides preassembled to the plate. 
         FIG. 24  is a side elevation of the tool of  FIG. 23 , shown rotated 90° relative thereto. 
         FIG. 25  illustrates a method of assembling a T-shaped plate to bone with the tools of  FIG. 23 . 
         FIG. 26  illustrates a method a assembling a web plate to bone with the tools of  FIG. 23 . 
         FIG. 27  is a top view of the method of  FIG. 26 . 
         FIG. 28  illustrates the web plate shaped to the bone. 
         FIG. 29  is a perspective view of a locking screw according to the invention. 
         FIG. 30  is a broken section view of the locking screw of  FIG. 29 . 
         FIG. 31  is a perspective view of a non-locking screw according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A bone plate system for the internal fixation of small bones, such as metacarpal and phalangeal bones of the hand, is provided and includes bone plates  10  ( FIGS. 1 through 3 ),  110  ( FIGS. 5 through 8 ),  210  ( FIGS. 9 through 12 ),  310  ( FIGS. 13 through 17 ), and  410  ( FIGS. 18 through 22 ). 
     Referring to  FIGS. 1 through 3 , bone plate  10  is a plate with a straight rail  12  defining a longitudinal axis A of the plate. The rail  12  includes a linear arrangement of ring-shaped screw hole boundaries  14 , with adjacent boundaries interconnected by respective webs  16 . The webs  16  each have a length L of 1.77, a width W of 3.05 mm, and a thickness T is 1.24 mm. The webs  16  have a lower surface  26  which is recessed relative to the lower bone contacting surfaces  28  of adjacent boundaries. Each boundary  14  defines a screw hole  18   a ,  18   b  for receiving a screw. The screw holes are either locking screw holes  18   a  or elongated non-locking screw holes  18   b . Locking screw holes  18   a  having internal threads  20  for engaging the threads at the head of a locking screw  620  ( FIG. 29 ) or for receiving a guide  30  ( FIG. 4 ), as discussed in more detailed below. The center-center distance C for adjacent locking screw holes is 7.42 mm. Screw holes  18   b  are dynamic compression plate (DCP) holes each with a respective upper recess  22  for receiving the convex lower surface of a non-locking multidirectional screw  640  ( FIG. 31 ), as also discussed below. The locking and DCP screw holes  18   a ,  18   b  may be symmetrically or asymmetrically arranged along the length of the rail. An embodiment of the plate  10  has a length of 90 mm which is ideal for placement on the metacarpal bones. 
     Referring generally to  FIGS. 1 ,  3  and  4 , the threaded locking screw holes  18   a  are each preferably preassembled with a guide  30 . The guide  30  has a cylindrical upper body  30   a , a threaded lower portion  30   b  for engaging locking screw holes  18   a , a circumferential lip  30   b  between the upper and lower portions  30   a ,  30   b  that seats on the upper plate surface of a screw hole boundary  14 , a bore  30   d  and a driver engagement structure  30   e , e.g., inner corners. As described in co-owned US Pub. Nos. 20060149250A1, 20060161158A1, 20070233111A1, which are hereby incorporated by reference herein in their entireties, and discussed further herein below, the guides  30  and associated tools  500  (also discussed below with respect to  FIGS. 23 through 27 ) facilitate (i) bending the plate while the plate is positioned on the bone, (ii) directing a drill through the threaded holes along the fixed axis of the helical thread without necessitating assembly of a separate drill guide during the surgical procedure, and (iii) repeated stressing of the plate along the web between adjacent guides to cause controlled removal of a portion of the plate. In view of point (iii), plate  10  and all plates of the system, can be readily shortened in length or otherwise modified in shape to accommodate a particular bone fracture, bone feature, or individual patient anatomy. 
     Referring to  FIGS. 5 through 8 , bone plate  110  is generally T-shaped, comprising a straight rail  112 , substantially similar to rail  12 , and a transverse portion  114  at one end of the rail. The rail  112  includes a linear arrangement of ring-shaped screw hole boundaries  118  defining screw holes, described below, with adjacent boundaries connected by respective webs  122 . The webs  122  of the rail  112  each have a length L 1  of 1.77 mm, a width W 1  of 3.05 mm, and a thickness T 1  of 1.24 mm. The transverse portion  114  includes two oppositely-directed extensions  124   a ,  124   b  at one end of the rail. The extensions  124   a ,  124   b  also include screw hole boundaries  126 , with adjacent boundaries connected by respective webs  128 . Webs  128  each have a length L 2  of 1.48 mm, a width W 2  of 2.16 mm, and a thickness T 2  of 1.4 mm. The larger dimensions of the webs  122  of the rail  112  relative to the webs  128  of the extensions  124   a ,  124   b  provide a rail with increased torsional stiffness relative to the extensions. This allows the extensions  124   a ,  124   b  to be relatively easily shaped to the bone (as described below) without inadvertently imparting a twist to the straight rail  112 . As a result, the surgeon can more freely manipulate the extensions in bending without concern for deformation of the rail. The lower bone contacting surfaces  132  of the boundaries along the extensions  124   a ,  124   b  are preferably arranged along a 120°±20° curve (transverse to the longitudinal axis A) at a radius of 13.3 mm to conform to the shape of the bone on which the plate is seated. 
     An embodiment of the T-shaped plate  110  has an overall length of 73.8 mm, a transverse dimension Dt from the side of one extension to the side of the other extension of 27.6 mm, and a vertical dimension Dv defined between the rail at the center of the extensions and the ends of the extensions of 10.5 mm. In the embodiment shown, the rail  112  includes ten threaded locking screw holes  120   a , and one non-locking oblong (DCP) screw hole  120   b  for dynamic compression of a fracture during fastener insertion through the hole. The DCP screw hole  120   b  is positioned with seven locking screw holes  120   a  on side and three locking screw holes  120   a  on the other side thereof. The extensions  124   a ,  124   b  each include two locking screw holes  120   a . The T-shaped plate  110  is sized and shaped for metacarpal fractures. As shown in  FIG. 8 , the threaded locking screw holes  120   a  of the plate are preferably pre-assembled with guides  30 . 
     Turning now to  FIGS. 9 through 12 , bone plate  210  is a Y-shaped plated, having a straight rail  212 , and two extensions  216   a ,  216   b  branched off one end of the rail. The rail  212  is substantially similar to rail  112 , with webs  222  having the same web dimensions as  122 , but rail  212  may be of different length and may include a different number of screw hole boundaries  218 , and have a different number of threaded screw holes and DCP holes. The extensions  216   a ,  216   b  have webs  226  with the same dimensional properties as the extensions of the T-shaped plate. The extensions  216   a ,  216   b  include respective first portions  234   a ,  234   b  angled relative to each other, and second portions  236   a ,  236   b  parallel to each other. The first portions  234   a ,  234   b  are preferably angled relative to each other in the plane of the rail  212  at an angle α, wherein α=60°±10°. The relatively angled first portions  234   a ,  234   b  provide relief to a tendon attachment point. The parallel second portions  236   a ,  236   b  extend alongside the bone to saddle or buttress the condyles of either the head or base of the long bones of the hand or foot, e.g., metacarpals, phalanges and metatarsals. The parallel second portions  236   a ,  236   b  also permit placement of screw hole boundaries laterally on either side of tendon attachments located on the dorsal side of the head or base of the long bones of the hand or foot. The lower bone contacting surfaces  238   a ,  238   b  of the boundaries of the extensions  216   a ,  216   b  are preferably arranged along a 60°±5° curve (transverse to the longitudinal axis A) at a radius of 15.2 mm. In one embodiment, the plate  210  has an overall length of 71.9 mm, a transverse dimension Dt from the side of one extension to the side of the other extension of 19.5 mm, and a vertical dimension Dv defined between the rail at the center of the extensions and the ends of the extensions of 4.5 mm. In the embodiment shown, the extensions  216   a ,  216   b  each include three screw hole boundaries  218 , with the first portions  234   a ,  234   b  defined from respective first and second screw hole boundaries, and the second portions  236   a ,  236   b  defined from respective second to third screw hole boundaries to engage the condyles of the bone. As shown in  FIG. 12 , the threaded holes of the plate are preferably pre-assembled with guides  30 . 
     Referring now to  FIGS. 13 through 17 , bone plate  310  has a straight rail  312 , a transverse portion defined by two opposing extensions  314   a ,  314   b  at one end forming a T-shape, and two extensions  316   a ,  316   b  in a Y-shape configuration at its opposite end; plate  310  is referred to as a TY-shaped plate. 
     In the embodiment shown, the T-shape portion is generally similar to T-shape plate  110 , but is distinguished by each extension  314   a ,  314   b  having a single screw hole boundary, each with a locking screw hole  320   a  on each side of the rail  312 . The transverse dimension Dt 1  from the side of one extension  314   a  to the side of the other extension  314   b  is 19.5 mm, and the overall vertical dimension Dv 1  defined between the rail  312  at the center of the extensions and the ends of the extensions of 4.7 mm. The lower bone contacting surfaces  338  of the boundaries of the extensions  314   a ,  314   b  are preferably arranged along a 60°±5° curve (transverse to the longitudinal axis A) at a radius of 13.9 mm. 
     The Y-shaped portion is generally similar to Y-shaped plate  210 , but is distinguished by each extension  316 ,  316   b  having four screw hole boundaries, each with a threaded screw hole  320   a , with three screw holes in each of the parallel second portions  322   a ,  322   b . The transverse dimension Dt 2  from the side of one extension  322   a  to the side of the other extension  322   b  is 19.5 mm, and the overall vertical dimension Dv 2  between the rail  312  at the center of the extensions  316   a ,  316   b  and the ends of the extensions is 4.5 mm. The lower bone contacting surfaces  340  of the boundaries of the extensions are also preferably arranged along a 60°±5° curve (transverse to the longitudinal axis A) at a radius of 15.2 mm. 
     The webs  322  of the rail  312  each have a length of 1.77 mm, a width of 3.05 mm, and a thickness of 1.24 mm. The webs of the extensions each have a length of 1.48 mm, a width W 2  of 2.16 mm, and a thickness of 1.4 mm. Thus, the webs of the rail are stiffer than the webs of the extensions. The plate  310  has an overall length of 55.5 mm. The TY-shaped plate is preferably sized and shaped to conform to the bone for metacarpal fractures. As shown in  FIG. 17 , the locking screw holes in the plate are preferably pre-assembled with guides  30 . 
     Turning now to  FIGS. 18 through 22 , bone plate  410  includes a straight rail  412  with screw hole boundaries  418 , and a plurality of extensions  424  extending from the screw hole boundaries at each side of the rail. The extensions  424  each include a single screw hole boundary  418 . The webs  422  of the rail  412  each have a length L 1  of 1.77 mm, a width W 1  of 3.05 mm, and a thickness of 1.24 mm. Webs  428  of each extension have a length L 2  of 1.48 mm, a width W 2  of 2.16 mm, and a thickness of 1.4 mm. In one embodiment of the plate  410 , the terminal boundaries of the rail are each provided with two extensions in (opposing) Y-shaped configurations  432   a ,  432   b , and a relatively longitudinally central boundary is provided with two extensions  424   a ,  424   b  in a diagonally opposed relationship. The remaining boundaries include only a single web at an oblique angle relative to the longitudinal axis A. In the embodiment shown in  FIGS. 18 through 21 , along a first side of the plate four adjacent extensions  424  are in a parallel relationship, non-orthogonally angled relative to the longitudinal axis A in the plane of the rail at an angle β, wherein β=60°, and three adjacent extensions are in a parallel relationship, at an opposite angle −β relative to the longitudinal axis A. Along a second side of the plate, three adjacent extensions are in a parallel relationship, non-orthogonally angled at β in the plane of the rail relative to the longitudinal axis A, and three adjacent extensions are in a parallel relationship at an opposite angle −β relative to the longitudinal axis A. 
     Referring to  FIG. 21 , the transverse dimension Dt from the side of an extension on one side of the rail to an extension on the other side of the rail is 17.4 mm, and the overall vertical dimension Dv between the rail at the center of the extensions and the ends of the extensions of 4.5 mm. The lower bone contacting surfaces  440  of the boundaries of the extensions are also preferably arranged along a 60°±5° curve (transverse to the longitudinal axis A) at a radius of 11 mm. As seen best in  FIGS. 19 and 20 , the arrangement of the extensions  424  relative to the rail  412  provides a staggered arrangement of threaded screw holes  420  such that the fixed angle trajectory of the axes of the holes in the extensions  424  do not intersect the trajectories of the axes of the threaded screw holes in the rail  412 . The plate  410 , referred to as a web plate is both laterally and longitudinally asymmetrical, with higher plate hole density at the ends of the plate and along one side of the plate. The asymmetrical shape of the web plate allows a surgeon to select to which side of the straight rail (left or right) a larger concentration of screw hole boundaries will be provided on the bone by rotating the plate about an axis normal to the top surface of the plate. ( FIG. 22  shows a similar plate oriented to provide a higher concentration of plate holes along an opposite side relative to the plate in  FIG. 19 ). The web plate  410  also provides a net or cage along the bone shaft for high energy or segmental bone loss application. This can be accomplished by bringing the extensions in along the bone and leaving them unfilled with bone graft. The web plate  410  is preferably sized and shaped to conform to the bone for metacarpal fractures, and is designed to maintain the length of a bone even where there is extensive bone loss due to injury. The plate of  FIGS. 18 through 21  has a length of 79 mm. As shown in  FIG. 22 , the plate may have a shorter rail with fewer screw hole boundaries and thus a shorter length. Similarly, the plate may have a longer rail with more screw hole boundaries and thus a longer length. As also seen in  FIG. 22 , the locking screw holes in the web plate  410  are preferably pre-assembled with guides  30 . 
     As discussed above, each of the plates is preferably pre-assembled with guides  30 . Referring to  FIGS. 23 and 24 , plate bending tools  500  (one such tool is shown, however the tools are generally used in pairs) may be attached to the guides and/or plate while the plate is located on or off the bone to effect alteration of the plate shape in an effective and precise manner. Each bending tool  500  includes a first end  552 , a second end  554 , and an L-shaped handle  556  extending therebetween. The first end  552  defines a longitudinal axis A 1 , the second end defines a longitudinal axis A 2 , and axes A 1  and A 2  are orthogonal relative to each other. The only distinction between the two tools of a pair of tools is that the handles  556  of a pair extend in opposite directions relative to each other. 
     Referring to  FIGS. 23 ,  24  and  25 , the first end  552  defines a socket  560  sized to closely receive the tip  30   a  of a guide  30 , and means for rotationally fixing the first end  552  relative to a portion of the bone plate, such as the webs  122 ,  128  of T-shaped plate  110 , although the tools work the same with any of the plates. In a preferred embodiment, the means for rotationally fixing the first end relative to the bone plate are two feet  562 ,  564  that straddle the webs  122 ,  128  of the plate  110 . The two feet  562 ,  564  include curved inner surfaces  566  that seat about the radiused screw hole boundaries  118 ,  126  of the plate to quickly and easily align the tool  500  on a plate. The feet  562 ,  564  each have a toe end  574  for abutting the web, e.g.,  122 , at a fulcrum location, and a heel end  576  for applying force to a screw hole boundary  118 . Then, rotation of the second end  554  of the handle  556  relative to the plate  110  imparts a force to the plate that effects bending of the plate in the plane of the plate about the fulcrum. The second end  554  of the tool defines a bore  580  with a central longitudinal axis A B  oriented an oblique angle relative to the longitudinal axis A 2  of the second end  554 . The angle φ between A 2  and A B  is 160°±15°. The bore  580  is sized in diameter to be closely received over the tip  30   a  of the guide  30 . The bore  580  preferably includes an enlarged lower portion  582  for receiving the shoulder portion  30   c  of the guide  30  so that the tool can seat flush on the upper surface of the plate. The bore  30   d  of the guide  30  is also sized to receive a drill guide  600  (for drilling a screw hole through the guide) and a K-wire  610  (for temporary fixation of the plate through the guide). 
     Referring to  FIGS. 26 and 27 , a web plate  410  is shown with guides  30  preassembled thereto. The web plate  410  has been shortened from an initial length through the use of the tools. That is, tools  500  have been coupled to guides  30  on either side of the web  422   a  which is to be a new terminus of the plate, and the tools are operated to repeatedly reverse bend the plate at the web  422   a  in the longitudinal direction until the plate separates at the web to reduce the length of the plate and provide a new plate terminus  450 . Such ability to remove and method of removing a portion of a plate applies to all plates of the system and all portions of the plates, including any extension thereof, or portions of extensions thereof. 
     The plate  410  is provisionally coupled to a small long bone such as a phalangeal bone  612  (or metacarpal bone) with screws  620  inserted through an end locking screw hole  420   a  and the locking screw hole  420   b  of the new terminus  450  thereof and into the bone  612 . 
     The extensions  424  of the plate  410  are shaped to the bone  612  with the tools  500 . The bores  580  of respective tools  500  are positioned over the bodies  30   a  of the guides  30  and appropriate relative force is applied to re-orient the screw hole boundaries  418  as necessary to (i) seat the bone contacting surface of the plate close to the underlying bone and/or (ii) orient the locking screw hole axes such that locking screws inserted through the locking screw holes will be oriented in a desired direction so as to engage desired bone and bone fragments without interference with other locking screws. With the bending tools  500  coupled to the guides and plate in the described manner, the plate  410  may be bent along any web in concave and convex directions (longitudinally) and rotationally along an axis of any web (in torsion). The screw hole boundary of each extension can be oriented independently of all other screw hole boundaries. Once a web has been bent to orient a screw hole boundary  418 , a K-wire may be inserted through the bores of the tool  500  and guide  40  to temporarily fix the location of the boundary (and overcome any springback in the plate)(as shown in  FIG. 25 ), or a hole may be drilled through the bores of the tool  500  and guide  30  with drill  600  for receiving a locking screw. The bore  580  of the tool  500  is sized so that the tool may be withdrawn from over the K-wire, guide and/or drill, while leaving such components in place relative to the plate. Once the hole is drilled, the guide  30  may be removed and a locking screw  620  may be inserted.  FIG. 28  illustrates the plate  410  fully shaped over the bone  612  and fragments, with guides removed. It should be appreciated that additional locking screws  620  may be inserted through the plate  410  and into the bone throughout the plate shaping procedure. 
     While the above plates have dimensions particularly suitable for metacarpal application, the shapes, structures, and benefits or such plate are equally applicable to treatment of fractures of smaller long bones such as the phalanges. However, it is anticipated that the plates will be scaled down in size (with appropriately scaled dimensions for plate holes, rail webs, extension webs, lengths, etc.) for use on such smaller bones. An appropriate scaling for phalangeal application would be plates seventy percent of the size of the plates described above for metacarpal use. 
     Turning now to  FIGS. 29 and 30 , a locking screw  620  is provided specifically for use with thin scaled-down plates (approximately 1 mm thick) such as for treating phalangeal fractures. The locking screw  620  is preferably made from cobalt chrome alloy. The locking screw  620  includes a head  622  and shaft  624 . The head has machine threads  625  that extend about 1.0±0.1 mm of vertical distance of the head. The head  622  also has a non-circular socket  626  with a flat bottom recess  628  that optimizes the material thickness T m  between the socket  626  and a lower surface  630  of the head. The minimum material thickness T m  is preferably 0.4±0.1 mm, and allows a socket  626  with sufficient driver engagement without reducing the torsional strength of the head to shaft attachment relative to screws for designed for larger plates. The above features provide a screw with a low profile head design but the strength of a larger screw. The shaft  624  preferably has bone engaging threads  632 , but may optionally be smooth. The thin low profile of both the plate and the locking screw minimizes soft tissue irritation. 
     Referring to  FIG. 31 , a non-locking multidirectional screw  640  is also provided for use in the non-locking holes of the plates of the system. The screw  640  is preferably made from titanium alloy. Screw  640  has a non-threaded head  642 , preferably with a rounded lower surface  644 , and a threaded shaft  646 . Each of the locking and non-locking screws  620 ,  640  may be provided in various lengths. In addition, all the holes of the various plates may be locking, non-locking, or in a different locking/non-locking arrangement than described above to receive the screws  620 ,  640 . 
     The plates of the system are uniquely shaped for fixation of most types of metacarpal/phalanx fractures. The straight plate  10 , T-shaped plate  110 , Y-shaped plate  210 , TY-shaped plate  310 , and web plate  410  provide all the shapes required for fixation of all fractures in such small bones, and as a kit or system provide options for small long bone fixation that is not available in any other kit or system. Such shapes are each highly configurable through the shaping procedure described herein so as to adaptable to individual patients and the unique circumstances of a given fracture. Further, by changing the length of the various plates (through reverse bending), the functional structural aspects of the individual plates remains. In addition, given the high symmetry in certain individual plates (each of the straight plate, T-shaped plate, Y-shaped plate, and TY-shaped plate are laterally symmetrical), they are adapted for both left and right hand use. Moreover, the asymmetry of the web plate permits the surgeon to concentrate fasteners to one side of bone, if required. Each of the plates of the present system may be formed from any one of numerous materials known in the art, including stainless steel, titanium, and titanium alloy such as Ti-6Al-4V. 
     There have been described and illustrated herein embodiments of a system for treating small bone fractures, including bones of the metacarpals and phalanges, and individual plates therefor. In addition, methods of customizing the plates to various bones are described. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. By way of example, various dimensions of the plates sized for metacarpal application are provided, as well as a scaling factor for plates for smaller bones. While preferred dimensions for plates for such application are provided, it is appreciated that variations in dimension (e.g., ±ten percent) are permissible provided such variations do not cause the extensions to have a higher torsional stiffness than the rail in the respective plates. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.