U.S. patent application number 13/209326 was filed with the patent office on 2012-02-02 for compression bone staple, apparatus and method of the invention.
This patent application is currently assigned to Dallen Medical, Inc.. Invention is credited to Drew Allen.
Application Number | 20120024937 13/209326 |
Document ID | / |
Family ID | 23154131 |
Filed Date | 2012-02-02 |
United States Patent
Application |
20120024937 |
Kind Code |
A1 |
Allen; Drew |
February 2, 2012 |
COMPRESSION BONE STAPLE, APPARATUS AND METHOD OF THE INVENTION
Abstract
A method and apparatus for interosseous bone fixation uses a
compression staple, generally U-shaped, having a pair of legs with
sharp front ends and proximal ends interconnect by a bridge portion
that is resilient and bowed, the staple having an initial
configuration and capable of a tensioned configuration by spreading
apart the legs by a certain amount causing the curvature of the
bowed bridge to lessen and the legs urged towards each other with
certain compressive spring force. A staple applicator supports and
guides the staple and positions the tensioned staple with its
pointed ends forward, adjacent an ejection port at the front of the
applicator. A powered strike member is mounted for longitudinal
movement and has a front end that will strike the rear of the
tensioned staple with percussive force and eject it in tensioned
configuration from the applicator.
Inventors: |
Allen; Drew; (San Jose,
CA) |
Assignee: |
Dallen Medical, Inc.
San Clemente
CA
|
Family ID: |
23154131 |
Appl. No.: |
13/209326 |
Filed: |
August 12, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10896360 |
Jul 20, 2004 |
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13209326 |
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09985719 |
Nov 6, 2001 |
6783531 |
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10896360 |
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09500060 |
Feb 8, 2000 |
6348054 |
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09985719 |
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09299285 |
Apr 26, 1999 |
6059787 |
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09500060 |
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Current U.S.
Class: |
227/181.1 |
Current CPC
Class: |
A61B 17/1227 20130101;
A61B 17/068 20130101; A61B 17/0682 20130101; A61B 17/0642
20130101 |
Class at
Publication: |
227/181.1 |
International
Class: |
A61B 17/00 20060101
A61B017/00 |
Claims
1. A bone staple applicator for driving one or more bone staples
into bone segments to secure the bone segments across a fracture
site, each bone staple comprising two legs and a substantially flat
bridge portion coupling the two legs to one another, the two legs
and substantially flat bridge portion each having inside surfaces,
the bone staple applicator comprising: an elongate main body having
a proximal end, a distal end, and a longitudinal axis extending
therethrough; a bone staple feeder having a proximal end, a distal
end coupled to the distal end of the elongate main body to define a
bone staple receiving channel, and a longitudinal axis extending
between said proximal and distal ends that is substantially
perpendicular to the longitudinal axis of the elongate main body,
the bone staple feeder being adapted to feed a bone staple into the
bone staple receiving channel, wherein the bone staple feeder
comprises an elongate ramp member and a pusher slidably coupled to
the elongate ramp member, the elongate ramp member being adapted to
slideably engage the substantially flat inside surfaces of the two
legs and substantially flat bridge portion of each bone staple, the
ramp member further being adapted to accommodate a plurality of
bone staples in a side-by-side configuration wherein the two legs
of a first bone staple are adjacent to the two legs of an adjacent
second bone staple; and a staple striker slidably coupled to the
elongate main body and adapted to strike the substantially flat
bridge portion of the bone staple placed in the bone staple
receiving channel with sufficient percussive force to drive the
legs of said bone staple into bone.
2. The bone staple applicator of claim 1, wherein each bone staple
does not any protrusions extending proximally from the
substantially flat bridge portion.
3. The bone staple applicator of claim 1, wherein each bone staple
has a relaxed configuration wherein the two legs of the bone staple
converge toward one another and a tensioned configuration wherein
the two legs of the bone staple are substantially parallel.
4. The bone staple applicator of claim 3, wherein the elongate ramp
member has a proximal end and a distal end, and wherein the
elongate ramp member is shaped to urge a bone staple from the
relaxed configuration to the tensioned configuration as the pusher
advances the bone staple from the proximal end of the elongate ramp
member to the distal end of the elongate ramp member.
5. The bone staple applicator of claim 4, wherein the elongate ramp
member comprises side surfaces adapted to face the inside surfaces
of the two legs of a bone staple.
6. The bone staple applicator of claim 5, wherein the side surfaces
have a convergent orientation at the proximal end of the elongate
ramp member.
7. The bone staple applicator of claim 5, wherein the side surfaces
have a substantially parallel orientation at the distal end of the
elongate ramp member.
8. The bone staple applicator of claim 3, wherein the elongate ramp
member has a proximal end and a distal end, wherein the distal end
of the elongate ramp member is adapted to maintain a bone staple
fed into the bone staple receiving channel in the tensioned
configuration.
9. The bone staple applicator of claim 1, wherein the pusher is
adapted to advance a second bone staple into the bone staple
receiving channel after a first bone staple has been driven out of
the bone staple receiving channel by the staple striker.
10. The bone staple applicator of claim 8, wherein the bone staple
feeder comprises a spring coupled to the pusher to advance the
pusher.
11. The bone staple applicator of claim 1, wherein the staple
striker is adapted to drive the legs of a bone staple into bone
such that the legs are maintained in a substantially parallel
orientation in the bone.
Description
CROSS-REFERENCE
[0001] This application is a continuation application of U.S. Ser.
No. 10/896,360, filed Jul. 20, 2004, which is a continuation
application of U.S. Ser. No. 09/985,719, filed Nov. 6, 2001, now
U.S. Pat. No. 6,783,531, issued Aug. 31, 2004, which is a
continuation application of U.S. Ser. No. 09/500,060, filed Feb. 8,
2000, now U.S. Pat. No. 6,348,054, issued Feb. 19, 2002, which is a
continuation-in-part application of U.S. Ser. No. 09/299,285, filed
Apr. 26, 1999, now U.S. Pat. No. 6,059,787, issued May 9, 2000,
which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to devices and techniques for
securing bone segments across a fracture site, and more
particularly relates to a bone stapling method and apparatus for
achieving compression between segments.
[0004] 2. Description of the Prior Art
[0005] In treating a bone fracture it is common practice to fasten
one bone segment to the other so as to stabilize and immobilize
them for the duration of the bone consolidation process. Thus there
is the technique of internal fixation or direct mechanical
fastening of the bone segments.
[0006] Traditionally, fixation has been accomplished by variety of
apparatus and techniques, the more common involving the use of
metallic fastening devices such as screws, connector plates
(secured to the bone by screws), pins and clips. These methods
invariably involve the drilling of screw holes in the bone and the
use of related equipment such as drill hole templates.
[0007] Conventional U-shaped clips have also been used, the clip
legs being installed one each in holes in the opposing bone
segments. The rigid structure of such clips, like the other
fixation devices mentioned above, provide rigid immobilization of
the fracture zone. Such devices also served to maintain the
distance between segments, which was found however, among other
things, to hinder compression induced by contractions of skeletal
muscles in some cases, and prevent the establishment of compressive
force between the bone segments which is favorable to bone
consolidation or knitting. In this regard the concept of creating
dynamic compressive force across an osteotomy or bone fracture site
has become well recognized as a technique to promote primary bone
healing, i.e. consolidation that is faster and of better
quality.
[0008] Thus there has evolved a number of fastening devices such as
clips and the like, designed to deliver compression. Accordingly in
U.S. Pat. No. 3,939,294 there is provided a clasp or clip of spring
material having a pair of spaced-apart, inwardly inclined legs
connected by a Z-shaped upper portion. Sloped holes are drilled in
adjoining bone segments and tools are used to manipulate and
install one leg, and then the other leg is pulled toward the other
hole , spreading the Z-shaped elastic portion, and then inserted in
the other hole. Unfortunately this method requires the drilling of
specially sloped holes, involves multiple steps and is
time-consuming, and like the conventional rigid fastening
techniques, requires relatively large surgical opening. Also, the
manual installation of the clip using hemostats and the like is
difficult, requires meticulous skill and handling.
[0009] In U.S. Pat. No. 4,838,254 the legs of a pair of metallic
clips are, inserted in pairs of specially angled bores in
respective opposing bone segments. The exposed tops of the two
installed clips then serve as fastening heads for a spring that is
connected between the clips.
[0010] In U.S. Pat. No. 4,841,960 the disclosed "compression" clip
is essentially a clip with opposing legs that are installed in
pre-drilled holes and features a crimpable web that joins the top
ends of the legs. A crimping tool is used to crimp the web in an
effort to set up compression between the embedded legs.
[0011] U.S. Pat. No. 4,852,558 also requires manual installation of
separate legs in pre-drilled holes, the tops of the install legs
then being interconnected with a ratchet mechanism which must be
operated to draw the legs together. This design appears inherently
limited regarding adjustability and maintenance of constant
pressure. In U.S. Pat. No. 5,660,188 the two legs of a clip must
also be installed in pre-drilled holes. The clip has a bridge of
two side-by-side crimpable elements, and the jaws of a crimping
tool must be used on the embedded clip to deformingly spread apart
these elements, causing the legs to draw to each other. The
foregoing techniques involving crimpable clips all appear to be
imprecise in setting up suitable compressive' forces, require hole
drilling and related problems, and do not lend themselves to
minimizing the size of the surgical opening.
[0012] In view of the limitations of the afore-mentioned methods,
stapling has been looked to as a potentially quick and effective
way for fastening bone segments, and as a way to produce
compression. Thus in U.S. Pat. Nos. 5,053,038 and 5,662,655
"compression" staples are applied to the bone by a powered stapler.
These staples have legs shaped with beveled ends and/or have
divergent legs that will be forced apart from each other during
implantation, which flexes springy upper parts of the legs thereby
tending to set up compression. Unfortunately there is concern for
trauma to the bone due to driving of the compound-shaped legs into
the bone mass, and there is little apparent precision in
establishing the desired compressive forces.
[0013] In view of the foregoing it is a general object of the
present invention to provide an improved method and for
interosseous fastening.
[0014] A more particular object is to provide quick and simple, yet
effective method for fastening bone segments with compressive force
between opposing bone ends.
[0015] Another object to provide such a method that minimizes the
size of the required surgical opening and associated trauma.
[0016] A further object to provide a method of bone stapling that
minimizes trauma to the bone tissue during implantation of the
staple legs.
[0017] Yet another object is to provide a method for stapling that
maximizes the capability of establishing a dynamic compression
level that is optimal for enhanced osseous healing.
[0018] A still further object is to provide simple, effective bone
fixation technique that is relatively easy to learn and
practice.
[0019] Another object is to provide for compression fixation in
applications where other techniques would not work or would not
deliver compression. For example, conventional fastening techniques
for handling a "Jones" fracture, i.e. one that is transverse to the
longitudinal extent of the bone segment, is difficult to address
using conventional fastening techniques, however the present
invention is particularly suitable to provide fastening for such
fractures.
[0020] Still another object is to provide stapling apparatus and
method in which there is enhanced selection capability regarding
the level of the compressive forces to be imparted.
[0021] There are a number of advantages in exterior bone fixation
techniques, where surgical incisions are not required and fasteners
are applied through the skin; and thus it is yet another object of
the invention to provide a bone stapling method that lends itself
well to exterior bone fixation.
[0022] These and other objects of the present invention are
achievable by way of the present invention of a bone stapling
method and apparatus that uses a generally U-shaped staple having
pair of spaced apart legs with sharp free ends and proximal ends
interconnected by bridge that has at least one resilient curved
portion, whereby spreading apart of the parallel legs lessens the
curvature of the curved portions which brings the staple to a
tensioned configuration in which one leg is resiliently urged
towards the other. In a preferred embodiment it is seen that the
bridge portion comprises a single bowed spring element, the
curvature of which lies in a plane normal to the axes of the staple
legs.
[0023] The novel fastening method involves first positioning the
fractured ends of a first and a second bone segment in proximate,
face-to-face relationship. The next step involves spreading apart
the staple legs by a certain amount and holding the staple in the
resultant tensioned configuration. The extent to which the staple
legs are separated can be varied in one preferred embodiment of the
invention, the induced compressive forces between the legs being
proportional to the amount of displacement of the legs as the bowed
portion is moved through range of motion in which elastic behavior
is exhibited. In this regard it should be evident that herein lies
one of the advantages of the present invention, i.e. the capability
of selecting the optimal compressive force for an application by
spreading apart the staple legs by a predetermined amount.
[0024] Next, as the staple is held in its tensioned configuration,
it is positioned with it sharp ends forward and aligned
respectively with surfaces of one bone segments and the other.
Finally the positioned staple, while maintained in its tensioned
configuration, is driven into the bone by percussive force, such
quick application being provided by a conventional air-powered
striker of a stapler according to the present invention, or by a
manually stuck staple applicator according to the invention. The
embedded staple legs will cause the opposing bone faces to be
pressed into each other with a predetermined amount of force.
[0025] Such stapling method lends itself advantageously to a staple
with a relatively narrow profile, wherein apparatus according to
the present invention include a staple applicator having within its
housing means for supporting the staple and guiding its movement
with legs pointed ends forwardly disposed, and adapted to receive
the staple in its initial un-tensioned configuration engaging its
legs and spreading them apart by certain amount and holding the
staple in its tensioned configuration adjacent the front end of the
housing, for ejection therefrom. One embodiment, of several, uses
opposing first and second grooves for engaging the staple legs and
means for adjustably moving one groove from the other. Another
embodiment employs grooves that diverge to spread the staple legs
as a staple is advanced there-along. Ejection means mounted for
longitudinal movement in the housing has a front end adapted to
strike the rear of the tensioned staple with percussive force which
is provided by air power or electrical power in preferred
embodiments.
[0026] The invention also includes a staple applicator that is
adapted for being manually driven.
[0027] Another related bone stapling method for compressively
securing adjoining bone segments uses a resilient metallic staple
that has legs with an initial convergent configuration with respect
to each other, and the legs are resiliently extendible into
parallel relationship, in which configuration a predetermined
amount of spring force will urge the legs towards their initial
convergent orientation. This method includes holding the normally
convergent staple in its legs-parallel configuration, positioning
the so-tensioned staple with its sharp ends aligned respectively
with adjacent bone surfaces; and then driving and embedding the
legs of the tensioned staple in the bone segments and releasing the
embedded staple, whereby the bone segments are joined, and opposing
surfaces of the bone segments are caused to be pressed into
engagement with each other with a certain amount of compressive
force.
[0028] An applicator or tool for such a staple includes
staple-engaging means on the front end of the applicator body.
Opposing jaws support the staple in a pointed-ends forward position
against lateral and rearward movement, and engage inside surfaces
of the convergent legs, the jaws being adapted for adjustable
movement apart to cause the legs to rotate to a generally parallel
orientation. Thus supported on the front end of the tool, the
staple can be aligned with the bone segments, and the rear end of
the tool stuck with a percussive force to cause the staple legs to
be embedded into the bone segments.
[0029] Another applicator according to the present invention has a
trigger-controlled air-powered staple-driving mechanism, and has a
staple feeding mechanism including ramp means that is shaped to
receive and support a staple in its initial configuration on one
end of said ramp means, the configuration of the ramp means
gradually changing to a shape that will hold the staple with its
legs generally parallel with each other. Thus the staple can be
slidably pushed along the ramp means in a lateral direction, i.e.
normal to the plane in which the staple legs and bridge portion
lie, to bring it to a terminal position along the ramp means, in
which position the rear of the tensioned staple can be struck by
the front end of a powered striker.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is perspective view of a preferred embodiment of a
compression staple according to the present invention;
[0031] FIG. 2 is top plan view of the embodiment of the staple of
FIG. 1;
[0032] FIG. 3 is a rear end elevational view of the staple of FIG.
1;
[0033] FIG. 4 is a perspective view of variant of a staple
according to the present invention;
[0034] FIG. 5 is an elevational view of staple applicator according
to the present invention, with parts broken away for the sake of
clarity;
[0035] FIG. 6 is a partial, perspective enlarged view of the front
end of the staple applicator of FIG. 5;
[0036] FIG. 7 is a sectional view taken long the line 7-7 of FIG.
6;
[0037] FIG. 8 is sectional view taken long the line 8-8 of FIG.
6;
[0038] FIG. 9 is an enlarged, partial perspective view of the front
portion of a variant of a staple applicator according to the
present invention;
[0039] FIG. 10 is an enlarged, partial perspective view of the
front portion of another variant of a staple applicator according
to the present invention;
[0040] FIG. 11 is a top plan view of a manually powered stapler
according to the present invention;
[0041] FIG. 12 is a partial, enlarged perspective view of the front
portion of the staple applicator of FIG. 11;
[0042] FIG. 13 is a sectional view taken along the line 13-13 of
FIG. 12;
[0043] FIG. 14 is a perspective view of another variant of a
compressive staple according to the present invention, wherein the
staple legs have a convergent orientation with respect to each
other;
[0044] FIG. 15 is a side elevational view of the staple of FIG.
14;
[0045] FIG. 16 is a top plan view of a staple applicator according
to the present invention;
[0046] FIG. 17 is an enlarged, partial perspective view of the
front end of the applicator of FIG. 16;
[0047] FIG. 18 is an enlarged partial, side elevational, partially
sectional view illustrating the mounting of a staple on the front
end of the staple applicator of FIG. 16;
[0048] FIG. 19 is a view similar to FIG. 18 showing a staple
supported with legs parallel;
[0049] FIG. 20 is a perspective view of a convergent-legged staple
that is adapted to be fed to a powered staple applicator;
[0050] FIG. 21 is a rear elevational view of the staple of FIG.
20;
[0051] FIG. 22 is a side elevational view of another powered
applicator according to the invention;
[0052] FIG. 23 is a perspective illustration showing means for
feeding staples to the staple-driving means of the powered staple
applicator shown in FIG. 22;
[0053] FIG. 24 is a partial, enlarged , partial sectional side view
of staple-delivering ramp member of the applicator shown in FIG.
22;
[0054] FIG. 25 is a schematic illustration of the staple-striking
region of the staple feeding means of FIG. 23;
[0055] FIG. 26 is a perspective view of another variant of another
compression staple similar to the staple of FIG. 1, and adapted for
use with a staple-feeding magazine or cartridge;
[0056] FIG. 27 is a front end elevational view of the staple of
FIG. 26; and
[0057] FIG. 28 is a partial sectional perspective view, with parts
broken away for the sake of clarity, illustrating a magazine or
cartridge for feeding the staple of FIG. 26 to a powered staple
applicator.
DETAILED DESCRIPTION OF THE INVENTION
[0058] Referring now the drawings, FIGS. 1-3 show that a preferred
embodiment of a compression staple 11 according to the present
invention has a pair of legs 13 with sharp front ends 15 and a
bridge 17 that interconnects the rear end, portions of legs 13.
Staple 11 is fabricated of a surgical grade, bio-compatible metal,
such as stainless steel, titanium alloy or other suitable alloy.
Bridge 17 functions not only to hold legs 13 in approximate
parallel relationship, but is selected to act as a spring by the
flexing of its bow when the legs are spread apart as illustrated by
the broken line image of FIGS. 2 and 3. This imparts an inward
reacting force between the legs proportional to the degree of their
displacement. It will be appreciated that the dimensions, gauge and
curvature of bridge 17 are selected such that it can be flexed to a
tensioned state that will deliver the compression requirements of
the bone fixation to which staple 11 is to be applied.
[0059] It is preferred that the opposing inside surfaces of legs 13
are provided with serrations or barbs 19. In this regard it is
noted that, inasmuch as the insides of legs 13 will be pressed
against bone mass when they are embedded in a manner to be
described, the size of such serrations or barbs can be
advantageously minimized, which minimizes trauma to the bone tissue
during their implantation.
[0060] It will be evident that there can be several variations of
compression staples according to the principles of the invention.
For example, staple legs can have various cross sectional
configurations, including diamond-shaped, square, triangular and
rectangular. FIG. 4 shows a variant 23 of a staple according to the
present invention, having legs 25. It is formed from metal rod
having suitable strength and spring properties. It is also
contemplated under the invention that the curvature of the bridge
can take other forms than the single bow shown, and would include,
among others a generally V-shape and a shape with double 90 degree
bends.
[0061] FIG. 5 shows an air-powered staple applicator 29 for
applying staple 11, and it includes main body 31, a conventional
air piston assembly 33 within body 31, air supply line 35 and a
pistol grip and trigger assembly 37 for holding the stapler and for
controlling the air-powered operation of the staple head 41, to be
described hereinafter.
[0062] As FIG. 6 illustrates, the staple head 41 features an
adjustable staple mount 43 that includes lower head 45 which is a
forward extension of body 31, and upper head 47. A pair of parallel
guide rods 51, affixed to lower head 45 and extending upwardly
therefrom, slidably engage twin bores 53 in the upper head 47 so as
to guide the upper head in vertical motion relative to the lower
head 45. A screw jack assembly drives the upper head and includes
thrust screw 55 that engages the threaded bore 57 in lower head 45.
FIG. 7 best illustrates the screw jack assembly and shows turn knob
59 that has a socket for receiving a tool such as an Allen wrench
for rotating the knob 59. FIGS. 6 and 7 also show a longitudinally
extending groove 65 on the lower head 45 and a corresponding
parallel groove 63 on the movable upper head 47, these grooves
being shaped to cradle the opposing sides of staple legs 13, and
the knob can be operated to set the spacing between grooves to
allow staple 11, in its initial un-tensioned configuration, to be
mounted thereon as illustrated.
[0063] In a preferred embodiment, vertically extending gradations
are provided at 67 on a forward surface of body 31, adjacent the
movable rear end of upper head 45, so as to gauge the displacement
of the staple legs when the invention is operated in a manner to be
described below.
[0064] As FIGS. 6 and 7 and 8 also show, staple applicator 29
includes mechanism for driving a staple forwardly from the staple
head 41, and includes longitudinally extending striker member 69
that is slidably mounted to grooves 71 and 73 for longitudinal
movement, and the rear portion (not shown), is connected to the air
piston assembly , and spring means (not shown) will hold the
striker in an initial rearward position as illustrated in FIG. 6.
Striker member 69 has front surface 75 that is adapted, as best
shown in FIG. 7, to impact the rear legs of the staple bridge 17
when the striker member 69 is propelled to its forward position
shown by the phantom lines in FIG. 6.
[0065] In the operation of staple applicator 29 for osteosynthesis,
a staple 11 is mounted to the staple mount 43 which is operated to
bring the staple to the desired tensioned configuration. Then bone
segments are brought together by manual or mechanical manipulation
as close as possible and aligned with each other. The stapler head
41 can then be positioned with its legs straddling the fracture
line, and sharp ends 15 adjacent the surfaces of the bone segments.
The stapler trigger can then be operated to cause the striker to
drive the legs of the tensioned staple into the bone segments.
[0066] There is a variant of a staple applicator according to the
invention that is identical to the embodiment of FIGS. 6 and 7,
except that it has a striker member 69a is designed to engage the
rear ends of staple legs 13 instead of the rear edge of the staple
bridge 17. Thus the sectional view of FIG. 9 shows ends 79 and 80
that are adapted to strike respectively the upper and lower rear
ends of staple legs 13, of a staple 11 supported in tensioned
configuration. It is contemplated under the invention that
`strikers like striker 69a, with differently spaced ends 79 and 80
can be provided so that different sized staples can be
accommodated.
[0067] FIG. 10 shows the forward portion 81 of another variant of a
power stapler applicator according to the present invention, having
a main body 82, an upper staple guide 83 and lower staple guide 85.
Opposing forward portions 87 of the guides are separated by a
distance allowing it to hold staple 11 in tensioned configuration,
and the rearward portions 89 will hold the staple in its initial
configuration. The open-sided portions 91 allow a staple to be
loaded by hand unto the staple guides. When the staple is pushed
forwardly by hand from portion 89 to portion 87, the divergent
portions 93 will cause the spreading apart of the staple legs, and
thus a tensioned staple is positioned for ejection.
[0068] A striker member 95 has upper and lower edges 97 and 99
slidably engaged in slots 101 and 103 so as to mount the striker
member for longitudinal movement. The striker front ends 105 and
107 will align with and abut the rear ends of a tensioned
staple.
[0069] FIGS. 11, 12 and 13 show a variant 113 of the invention,
whereby percussive force is delivered by hand using a suitable
mallet. Here the body 115 has a rear portion 117 designed for being
struck by a mallet, and staple holder 119 at its front end. FIGS.
12 and 13 show how the holder 119 includes lower portion 121 that
has staple leg-receiving groove 129, and an adjustable upper part
135 with groove 137. FIG. 12 best shows how a dove-tail portion 141
of part 135 fits in a complementary slot for guiding vertical
movement of part 135. Front surfaces 145 and 147 respectively of
parts 121 and 135 are adapted to abut the rear ends of a staple
mounted in grooves 137 and 129. A screw 153 for driving the part
135 has threads 157 that engage a threaded bore 159 in the movable
part 135, and the knob 163 can be engaged by a suitable tool to
rotate the screw 153.
[0070] In using tool 113 the sharp ends of a tensioned staple 11
can advantageously be precisely positioned on the target spots on
the bone segments, then the tool end 117 struck with a mallet to
implant the staple.
[0071] Referring now to FIGS. 14 and 15 there is shown in FIG. 14
another compressive staple 161 according to the invention that is
fabricated of a suitable resilient metal, and features legs 163 and
165 that converge with respect to each other, and interconnect by a
bridge 167. Staple 161 can also be made of a suitable resilient
non-metallic bio-absorbable material.
[0072] FIG. 15 best shows how legs 163 and 165 each converge at a
pre-selected angle .phi. with respect to parallel positions that
the legs can be resiliently urged in a manner to be described
hereinafter. It should be apparent that the material properties of
the selected resilient material, the degree of convergence, and the
dimensions and form of the staple will be selected by those with
ordinary skill in the pertinent art so as to establish a certain
force by which the parallel legs are urged to their convergent
positions.
[0073] FIG. 16 shows one preferred embodiment of a bone-staple
applicator 171 having a main body 173 with a rear end 175 adapted
for being impacted by a force delivering instrument like a mallet.
The front end 177 is designed to mount a staple 161 in its initial
configuration and then move it to, and hold it in, a configuration
where its legs are parallel. Thus it is seen in FIG. 17 that front
end 177 has an upper jaw 181 that can be adjustably spaced from to
a lower jaw 183 using drive-screw mechanism similar to that used
for the screw-driven spreadable parts 135 and 121 previously
described above and shown in FIGS. 12 and 13. FIG. 17 shows how the
upper jaw 181, and lower jaw 183 are shaped to mount a staple 161,
the slots 187 and 189 in the respective jaws being sized to receive
the staple bridge 167. A recessed portion 191 in the top of the jaw
181 is for supporting and stabilizing rearward portions of the
upper staple leg 163, and there is a similarly recessed portion on
the under-surface of the lower jaw 183 (not shown) for supporting
the rearward part 196 of lower staple leg 165. The recessed portion
191 has a shelf 193 for engaging lower surfaces of leg 163, and
opposing edges 195 can hold the staple against lateral movement
while the ledge 197 is adapted to abut the rear edge of the staple
leg.
[0074] FIG. 18 best shows how an untensioned staple 161 is first
mounted within the grasp of the opposing recessed portions of the
jaws 181 and 183, and it is noted how surfaces 193 and 194 engage
inner surfaces 211 and 213 of opposing legs 163 and 165. It should
be appreciated how the screw mechanism 217 can be operated to move
apart the opposing jaws, causing the opposing legs to be pushed
into parallel relationship, as illustrated in FIG. 19. When a
staple 161 is thusly mounted on the applicator tool 171, it can be
used much the same as the previously described device 113, to apply
a tensioned staple 161 to adjoining bone segments. Note that the
jaw surfaces 193 and 194 can be appropriately sloped to ensure that
the legs will be pushed into parallelism.
[0075] FIGS. 20 and 21 show another embodiment of a compression
staple according to the present invention, i.e. the staple 261
which is particularly adapted for application by a powered
applicator, for example an electrically powered or an air-powered
staple applicator such as applicator 271 shown in FIG. 22, to be
described. Like the previously described staple 161, the staple 261
is fabricated of a suitable resilient metal using conventional
metal-working techniques. The staple legs 263 and 265 extend from
the bridge portion 267 and converge at a predetermined angle. It is
noted how legs 263 and 265 are wider than the bridge portion 267.
The inside surfaces of the staple bridge and legs are adapted to
slidably engage staple-feeding ramp structure, to be described.
Furthermore, FIG. 21 best shows how this staple structure provides
to one side of the bridge 267, opposing inside surfaces 270 and 274
respectively of legs 263 and 265, which can be advantageously
engaged for slidable forward movement of the staple along parallel
guide surfaces in the powered staple applicator 271, in a manner to
be described.
[0076] The trigger-controlled applicator 271, shown in FIG. 22,
except for its forward end, is similar to the above-described
applicator 29, and includes a piston assembly 275. FIG. 23
illustrates how at the forward end of the applicator 271, there is
mounted a staple feeder 273 designed to supply and position staples
for engagement by the front end 279 of a striker 281 that is
connected to the piston assembly 275.
[0077] FIG. 23 shows that the feeder 273 includes a housing 285
that is attached to a sidewall of the applicator and which supports
a ramp member 287 that has a distal end 289 that is shaped to
receive staples 261. The walls 291, 292 and 293 are shaped so as to
be slidably embraced by a number of staples 261 in their relaxed,
legs-convergent configurations. FIG. 24 also illustrates the ramp
member 287 and shows how the ramp walls 291 and 292 vary from a
convergent orientation at one ramp end to a generally parallel one
at the opposite ramp end 294. FIG. 23 also illustrates that within
the feeder housing 285 there is a spring-powered pusher 295,
connected to a suitable conventional spring (not shown) for urging
the pusher 295 against the rear side edges of a staple 261 mounted
on the ramp member 287. Thus it can be appreciated how a staple
261, or several side-by-side staples 261, can be slidably pushed
towards the end 294 of the ramp member.
[0078] The enlarged view of FIG. 25 shows how the innermost end of
the ramp member 287 has an end 299 that is spaced from a guiding
surface 301 of applicator wall 304. Surfaces 301 and the opposing
upper and lower surfaces 303 and 305 form a channel as FIG. 24
shows, for receiving the striker 281. FIG. 25 shows in broken lines
a tensioned staple 261 in position for being driven by the striker
281. Note that the bridge member 267 is spaced within the
above-mentioned channel, clear of the end of the ramp member 287,
the staple being supported by virtue of the staple leg surfaces 270
and 274 (FIG. 21) engaging the ramp member. Thus the striker front
end 279 is aligned with the rear end of staple bridge portion
267.
[0079] In operation of applicator 271 it is supported with its
front end in close proximity to the relevant bone segments, and
with the pointed ends of the staple appropriately aligned
therewith. Pulling the trigger will cause the striker end 279 to
impact the staple bridge and propel the staple forwardly as the
staple legs are held generally parallel by sliding engagement with
the generally parallel surfaces of the ramp member 287 during
ejection.
[0080] The striker will have a stroke sufficient to cause the legs,
in their parallel configuration, to be embedded in the bone tissue.
The striker will return to its initial position rearward of the
ramp member. Then spring force will cause another staple to be
positioned in the ejection channel.
[0081] Although FIGS. 22 and 23 show the feeder 273 connected
adjacent the front end 260 of the applicator, it should be
appreciated that in some cases it is desirable that the feeder 273
attaches to the applicator 271 at a location spaced a greater
distance to the rear of the front 260. In such cases the ramp walls
291 and 292 in the region of wall 301 are elongated forwardly as
necessary to provide guide surfaces for the staple, and the stroke
of the striker 281 is increased accordingly.
[0082] FIGS. 26 and 27 illustrate yet another variant 361 of the
compression staple 11 described above (FIG. 1), and has generally
parallel legs 363 and 365 and resilient bridge 367. This
configuration provides opposing surfaces 370 and 374, best shown in
FIG. 27, that are adapted to engage parallel guide surfaces when
the staple 361 is propelled from a powered staple applicator 371;
to be described. In FIG. 27 the tensioned configuration of staple
361 in shown in broken lines.
[0083] FIG. 28 shows a feeder 373 which is constructed similarly to
the above-described feeder 273, except that the ramp member 387 is
adapted to handle the staple 361. Thus the ramp walls 391 and 392
provide parallel surfaces for engaging inside surfaces of the
staple legs and the wall 393 slidably abuts the wall 393.
[0084] The distal end of the ramp 387 receives staples 361 in their
untensioned condition, and the walls 391 and 392 gradually diverge
from each other such that at the other end 395 of the ramp, a
staple 361 will be supported in a legs-parallel tensioned
configuration. A spring-powered pusher 399 is adapted to urge a
number of nested staples 361 towards the end 395 of the ramp.
[0085] The ramp end 395 is spaced a predetermined distance from the
guide surface 401 and provides surfaces that engage the opposing
surfaces 370 and 374 of staple 361. Thus the rear of a tensioned
staple can be struck by the striker 397 and ejected from the
applicator.
[0086] While particular embodiments of the invention have been
described, it should be understood that the invention is not
limited thereto, and includes other variants and modifications that
will readily occur to those persons of ordinary skill in the art,
given the benefit of this disclosure. Thus it is intended that the
invention be given its full scope and breath as defined in the
claims which follow.
* * * * *