U.S. patent application number 13/712282 was filed with the patent office on 2013-06-13 for devices and methods for bone fixation using axial implants.
This patent application is currently assigned to Extremity Medical, LLC. The applicant listed for this patent is Extremity Medical, LLC. Invention is credited to Sammarco James Vincent.
Application Number | 20130150903 13/712282 |
Document ID | / |
Family ID | 48572701 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130150903 |
Kind Code |
A1 |
Vincent; Sammarco James |
June 13, 2013 |
DEVICES AND METHODS FOR BONE FIXATION USING AXIAL IMPLANTS
Abstract
The invention comprises a method for fixating bones in the foot
by aligning the bones in their desired position, inserting a screw
in the aligned bones, inserting at least one transverse element
near the head or tip of the screw, and tightening the screw to
compress the bones. The screw comprises a shaft having first and
second ends with spirally wound screw threads beginning near the
first end and extending along the shaft. Advantageously, the screw
is cannulated and screw threads are formed on an interior surface
of the cannulation. Illustratively, the transverse elements may be
staples, open-ended washers, or open-ended nuts. Reduction
instruments and drill guides used in the invention are also
disclosed.
Inventors: |
Vincent; Sammarco James;
(Cincinnati, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Extremity Medical, LLC; |
Parsippany |
NJ |
US |
|
|
Assignee: |
Extremity Medical, LLC
Parsippany
NJ
|
Family ID: |
48572701 |
Appl. No.: |
13/712282 |
Filed: |
December 12, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61569464 |
Dec 12, 2011 |
|
|
|
Current U.S.
Class: |
606/301 ; 606/79;
606/96 |
Current CPC
Class: |
A61B 17/7225 20130101;
A61B 17/86 20130101; A61B 17/8625 20130101; A61B 2017/681 20130101;
A61B 17/8875 20130101; A61B 17/8605 20130101; A61B 17/1725
20130101; A61B 17/864 20130101; A61B 17/8635 20130101; A61B 17/7291
20130101; A61B 17/151 20130101; A61B 17/1657 20130101; A61B 17/7241
20130101; A61B 17/8897 20130101; A61B 17/1697 20130101; A61B
17/7233 20130101; A61B 17/1775 20161101; A61B 2017/564
20130101 |
Class at
Publication: |
606/301 ; 606/96;
606/79 |
International
Class: |
A61B 17/86 20060101
A61B017/86; A61B 17/16 20060101 A61B017/16; A61B 17/17 20060101
A61B017/17 |
Claims
1. A method for compressing bones comprising: aligning the bones in
a desired configuration, inserting a screw into a borehole in the
aligned bones, inserting a first transverse element adjacent the
screw at a first position, and tightening the screw to compress the
bones.
2. The method of claim 1 wherein the step of inserting a first
transverse element adjacent the screw at a first position comprises
the steps of: drilling first and second holes on opposite sides of
the screw at the first position, and inserting the first transverse
element into the first and second holes.
3. The method of claim 1 further comprising the step of inserting a
second transverse element adjacent the screw at a second
position.
4. The method of claim 3 wherein the steps of inserting a first
transverse element adjacent the screw at a first position and
inserting a second transverse element adjacent the screw at a
second position comprise the steps of: drilling first and second
holes on opposite sides of the screw at the first position,
drilling third and fourth holes on opposite sides of the screw at
the second position; inserting the first transverse element into
the first and second holes, and inserting the second transverse
element into the third and fourth holes.
5. The method of claim 1 wherein the screw is cannulated and the
step of inserting the screw into the borehole comprises: mounting
the screw on a guide wire in the borehole, and inserting the screw
into the borehole on the guide wire.
6. The method of claim 1 wherein the bones that are compressed are
in a human foot.
7. The method of claim 1 wherein the first transverse element is a
staple, open washer or open nut.
8. The method of claim 1 wherein the screw has threads at one end
and the first transverse element engages the threads when it is
inserted adjacent the screw.
9. A method for compressing bones comprising: aligning the bones in
a desired configuration, forming a borehole on the aligned bones,
inserting a screw into the borehole, attaching a guide element to
the screw in the borehole, using the guide element to drill first
and second holes on opposite sides of the screw at a first
position, inserting a first transverse element into the first and
second holes, and tightening the screw to compress the bones.
10. The method of claim 9 further comprising the steps of: using
the guide element to drill third and fourth holes on opposite sides
of the screw at a second position, and inserting a second
transverse element into the third and fourth holes.
11. The method of claim 9 further comprising the step of using the
guide element at the first and/or second position to guide an
osteotome in cutting bone around the screw.
12. The method of claim 9 wherein the screw is cannulated and the
step of inserting the screw into the borehole comprises: mounting
the screw on a guide wire in the borehole, and inserting the screw
into the borehole on the guide wire.
13. The method of claim 9 wherein the bones that are compressed are
in a human foot.
14. The method of claim 9 wherein the first and second transverse
elements are staples, open washers or open nuts.
15. The method of claim 9 wherein the screw has threads at one end
and the first transverse element engages the threads when it is
inserted adjacent the screw.
16. A screw assembly comprising: a shaft having first and second
ends, threads on the shaft near the first end, a head on the shaft
at the second end, a first transverse element that engages the
threads on the shaft.
17. The screw assembly of claim 16 further comprising a second
transverse element that engages the shaft at a second position.
18. The screw assembly of claim 16 wherein the first and second
transverse elements are staples, open washers or open nuts.
19. The screw assembly of claim 16 wherein the shaft is
cannulated.
20. The screw assembly of claim 16 wherein the cannulated shaft has
an interior surface that is threaded.
21. A guide element for drilling holes adjacent a screw comprising:
a first element for mounting on the longitudinal axis of the screw,
a second element enclosing first and second holes, the second
element being located in the guide element such that when the first
element is mounted on the axis of the screw, the first and second
holes are located at a position such as to guide a drill to make
holes on opposite sides of the screw at a first desired position
along the axis of the screw, and a third element enclosing at least
third and fourth holes, the third element being located in the
guide element such that when the first element is mounted on the
axis of the screw, the third and fourth holes are located at a
position such as to guide a drill to makes holes on opposite sides
of the screw at a second desired position along the axis of the
screw.
22. The guide element of claim 21 further comprising a slot between
at least one of the first and second holes and the third and fourth
holes that is large enough to guide an osteotome.
23. The guide element of claim 21 further comprising a first slot
between the first and second holes and a second slot between the
third and fourth holes, each slot being large enough to guide an
osteotome.
24. The guide element of claim 21 wherein the third element is
mounted in the second element so that it can be moved in a
direction substantially parallel to the longitudinal axis of the
screw.
25. A reduction instrument for use in positioning a guide wire in
bone comprising: a handle with a central bore, and a shaft mounted
on the handle, the shaft having a cutting tip at an end remote from
the handle and a central bore that extends from the handle to the
cutting tip and is aligned with the bore in the handle, the central
bore of the handle and tip having an inside diameter sufficient to
pass a guide wire.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of provisional application
Ser. No. 61/569,464, filed Dec. 12, 2011, the entire contents of
which are incorporated herein by reference.
BACKGROUND
[0002] This invention relates to the field of orthopedic implant
devices. A typical application is as an intramedullary fixation
assembly used for the fixation of bones and the correction of
deformities in the foot.
[0003] Orthopedic implant devices such as intramedullary nails,
plates, rods and screws are often used to repair or reconstruct
bones and joints affected by deformity and disease such as Charcot
arthopathy caused by diabetes in some patients. Charcot arthopathy
(or Charcot foot) is a destructive process affecting many regions
including joints of the foot and ankle in diabetics. Charcot
arthopathy can affect any joint in the body but is often seen in
the foot. In the foot, the Charcot process typically affects the
tarsal and metatarsal bones and the tarsometatarsal and intertarsal
joints which causes the foot to lose its arch. This causes
fragmentation, dislocation and fractures that eventually progress
to deformity, instability and bony prominences. Foot ulcers may
develop which often lead to deep infection and sometimes
amputation.
[0004] FIG. 1 depicts a human foot 100 afflicted with Charcot
arthopathy. Phalanges 110, the first metatarsal 120, medial
cuneiform 130, navicular 140, and talus 150 bones are depicted in
foot 100. The deformity in the foot will be apparent.
[0005] Early treatment for Charcot foot includes the use of
therapeutic footwear, immobilization of the foot, and/or
non-weightbearing treatment. Surgical treatments include orthopedic
fixation devices that fixate the bones in order to fuse them into a
stable mass. These orthopedic implant devices realign bone segments
and hold them together in compression until healing occurs,
resulting in a stable mass.
[0006] Infection and complications are a major concern in these
procedures. Wound closure is technically demanding for the surgeon,
and devices that add surface prominence such as plates or exposed
screws, add to the difficulty by requiring greater tissue tension
during incision reapproximation. This increases the risk of
post-operative wound infections and dehiscence that may ultimately
result in limb amputation.
[0007] There is therefore a need for improvements in intramedullary
fixation assembly and methods of use that overcome some or all of
the previously described drawbacks of prior art fixation assemblies
and processes.
SUMMARY
[0008] The present invention is improved devices and methods for
bone fixation.
[0009] The improved devices include a screw for use in fixating the
bones and the combination of the screw with at least one transverse
element for use in compressing the bones. In a preferred
embodiment, the screw comprises a shaft having first and second
ends with spirally wound screw threads beginning near the first end
and extending along the shaft. Advantageously the screw is
cannulated and screw threads are formed on an interior surface of
the cannulation.
[0010] When the screw is implanted in a patient's foot, at least
one transverse element is secured to the screw near its first or
second end. By way of example but not limitation, the transverse
elements may be staples, open-ended washers, or open-ended nuts.
The screw is then tightened causing the bones along the screw to be
compressed.
[0011] Broadly, the methods of the invention comprise aligning the
bones in their desired position, inserting a screw in the aligned
bones, inserting at least one transverse element near the head or
tip of the screw, and tightening the screw. Further details of the
process are set forth below
[0012] Instruments are also disclosed for use in practicing the
invention. These include reduction instruments for use in aligning
the bones and a drill guide for drilling holes adjacent the screw
where one or more transverse elements may be inserted.
[0013] Numerous variations may be practiced in the preferred
embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other objects and advantages of the present
invention will be apparent to those of ordinary skill in the art in
view of the following detailed description in which:
[0015] FIG. 1 depicts a human foot afflicted with Charcot
arthopathy;
[0016] FIG. 2 is a cross-section of an illustrative embodiment of a
screw of the present invention;
[0017] FIG. 3 is a flow chart depicting illustrative steps of an
embodiment of the invention;
[0018] FIG. 4 depicts a reduction instrument used in the practice
of the invention;
[0019] FIGS. 5, 6, 8-11, and 15 depict details of certain of the
steps of FIG. 3;
[0020] FIG. 7 depicts a drill guide used in the practice of the
invention; and
[0021] FIGS. 12-14 depict several transverse elements that may be
used in the practice of the invention.
DETAILED DESCRIPTION
[0022] FIG. 2 is a cross-section of an illustrative embodiment of a
screw 200 that may be used in the practice of the invention. Screw
200 has an elongated shaft 210 having first and second ends 220,
225 and a longitudinal axis A-A extending along the shaft.
Preferably, the shaft is cannulated having a bore 230 that extends
from first end 220 to second end 225. On an exterior portion of the
shaft near the first end 220 are spirally wound threads 240 that
begin at approximately the first end 220 of the shaft. There may be
a head 250 on the shaft at its second end 225. The diameter of the
head may be wider than the diameter of the shaft. Alternatively,
the head may be set off from the remainder of the shaft by a recess
that circumscribes the shaft such as shown at 252 in FIG. 6. The
invention may also be practiced using a screw in which there are
threads at the second end of the screw in place of a head.
[0023] The head of the shaft includes a recess 255 open to the end
of the shaft that is shaped to receive an instrument such as a
screw driver or wrench in driving engagement. For example, by way
of illustration but not limitation, the recess may be hexagonal in
shape so as to receive a hexagonally shaped wrench similar to an
Allen wrench or the like; or the recess may be slotted so as to
receive the slotted blade of a screw driver. Alternatively, there
may be no recess in the head; and the head may be shaped, for
example, in a hexagon, to receive an instrument such as a socket
wrench or the like.
[0024] Optionally, numerous other refinements may be made in the
construction of the screw. For example, the screw may be reinforced
at points where forces are concentrated during use of the screw
such as the point 242 where exterior screw threads 240 end. The
threads may also be tapered at point 242. Spirally wound threads
may also be formed on an interior surface 232 of the bore 230. Such
threads can facilitate extraction of the screw if that becomes
desirable. The screw may also be treated by various processes to
increase its strength.
[0025] FIG. 3 is a flow chart depicting illustrative steps of an
embodiment of the invention used to treat Charcot arthopathy. It
will be understood that the flow chart is only illustrative, that
the order of execution of some steps may vary, and that some steps
may not need to be used in the treatment of a particular patient in
accordance with the invention. Initially, an incision is made in
the foot at step 310 to expose the metatarsal. Illustratively, the
incision is a doral Lis Franc incision. Next, the foot is
"gunstocked" at step 315. The bones of the foot, typically the
metatarsal, cuneiform, navicular and talus are then aligned at step
315 in the desired final position using a guide wire (e.g., a
K-wire) to secure the bones in the desired alignment.
[0026] Illustratively, the guide wire is inserted into the bones
using a reduction instrument such as instrument 400 of FIG. 4A.
Instrument 400 comprises a hollow sleeve 410 mounted on a handle
420. Sleeve 410 has a cutting tip 430 on the end of the sleeve
remote from the handle. A bore 435 extends through sleeve 410 and
handle 420 having an inside diameter that is large enough to allow
passage of a guide wire 440.
[0027] The diameter of guide wire 440 that may be used in the
practice of the invention can vary considerably depending on the
patient and the surgeon's preferences. Illustratively, the diameter
is in the range of approximately 1.0 to 4.0 millimeters (mm).
Different sleeve lengths may be used in the practice of the
invention depending on the size of the bones that are to be
aligned. Advantageously, instrument 400 is used with guide wire 440
sticking through tip 430, which allows guide wire 440 to be seated
and unseated in the bone. Advantageously, the other end of guide
wire 440 is keyed in handle 420 so that it can be easily maneuvered
by the handle.
[0028] After the bones are aligned on the guide wire as described
above, instrument 400 is removed from the guide wire. Returning to
the flow chart of FIG. 3, a drill bit is then mounted on the guide
wire; and a borehole is drilled at step 325 through one or more of
the aligned bones. This step is illustrated in FIG. 5 which depicts
drill bit 510 on guide wire 440 boring a hole in the aligned bones,
in this example, the first metatarsal, the medial cuneiform, the
navicular, and the talus bones of a left foot. The drill is then
removed; and a cannulated screw such as screw 200 of FIG. 2 is
mounted on the guide wire at step 330. Screw 200 is then screwed
into the borehole at step 335 using a screw driver 600 as shown in
FIG. 6.
[0029] A drill guide is then mounted on the screw at step 345. The
drill guide is used at step 350 to guide a drill bit in forming
first and second holes on opposite sides of the screw at a first
position that typically is just below the head of the screw. In
forming these holes, the drill bit breaks the cortex of the bone on
either side of the screw at the first position. The drill guide is
also used at step 355 to guide an osteotome that cuts the cortex of
the bone between the first and second holes at the first position.
Next, an element of the drill guide is positioned at a second
position above the threaded portion of the screw at step 360. This
element is then used at step 365 to form at least one pair of third
and fourth holes on opposite sides of the screw at the second
position. Again, the drill bit breaks the cortex of the bone on
either side of the screw in the second position. This element is
also used at step 370 to guide an osteotome that cuts the cortex of
the bone between the third and fourth holes at the second position.
The drill guide is then withdrawn at step 375.
[0030] The drill guide is shown as guide 700 in FIG. 7 and its use
is depicted in FIGS. 8-11. Guide 700 comprises a screw mount 710
that is screwed or clamped onto screw 200 so that it is aligned
with the longitudinal axis A-A of screw 200. The guide further
comprises a bracket 720 that is mounted on the screw mount 710 and
an extension arm 730 that is mounted on bracket 720 so that the arm
extends parallel to the longitudinal axis of screw 200. Bracket 720
encloses first and second holes 722, 724 and a slot 726 that
extends between the first and second holes. Extension arm 730
encloses several sets of third and fourth holes 732, 734 and a slot
736 that extends between the third and fourth holes. The first and
second holes are located in bracket 720 at a position such that
when bracket 720 is securely mounted on screw 200, the holes are on
opposite sides of the screw at the first position on the screw.
Extension arm 730 can be positioned so that the third and fourth
holes are on opposite sides of the screw at the second position on
the screw. The several sets of holes 732, 734 and slot 736 make it
possible to locate several transverse elements at the second
position. A ruler on the extension arm allows the surgeon to locate
the second position with precision.
[0031] FIG. 8 depicts screw mount 710 and bracket 720 mounted on
screw 200. FIG. 9 depicts depicts the use of hole 722 to guide a
drill bit 922 in drilling a hole into the cortex adjacent screw 200
in the first position; and FIG. 10 depicts the use of slot 726 to
guide an osteotome 1026 in breaking a hole in the cortex around
screw 200 at the first position. FIG. 11 depicts screw mount 710,
bracket 720 and extension arm 730 cooperating to locate the sets of
third and fourth holes 732, 734 and slot 736 at a second position
on the screw.
[0032] Returning to the flow chart of FIG. 3, at step 380, the two
ends of a staple, an open washer, an open nut or the like are
inserted into the first and second holes at the first position; and
the two ends of one or more staples, open washers, open nuts or the
like are inserted into the third and fourth holes at the second
position. The staples, washers, nuts as the case may be are then
driven at step 385 into their final position in the cortex so that
they engage the screw at the first position near the head and
engage the screw threads at the second position.
[0033] FIG. 12 depicts the profile of an open washer or open nut
1200. FIG. 13 depicts the profile of an open washer or open nut
1300 in position around screw 200. FIG. 14 depicts a staple 1400 in
position around screw 200. In each case, each washer or nut 1200,
1300 and each staple 1400 has two spaced-apart ends 1210, 1212;
1310, 1312; 1410, 1412 joined by a middle portion 1214, 1314, 1414,
respectively. The middle portion may be straight as in the case of
a conventional staple or rounded to varying degrees thereby
approximating the curvature of the exterior of the screw. For
convenience, the various elements such as staples, open washers,
open nuts and the like that may be used in the practice of the
invention will be referred to as transverse elements.
[0034] A screw driver is then used at step 390 to turn the screw so
as to bring closer together the transverse elements at the first
and second position, thereby compressing the bones between these
positions. This is illustrated in FIG. 15 which depicts a screw
driver 1500 being used to turn screw 200 to move staples 1510 and
1520 closer together. When this step is completed, the screw driver
is then removed and the incision is closed at step 395.
[0035] As will be apparent to those skilled in the art, numerous
variations may be practiced within the spirit and scope of the
present invention. For example, a variety of different tools--screw
drivers, wrenches, reduction instruments and drill guides--may be
used in the practice of the invention. Screws of different sizes
and different shapes may be used. Likewise different transverse
elements may be used. There may also be variation in the procedure
used to implant the screw and transverse elements in the foot. For
example, certain steps can be skipped or combined with other steps
and certain steps can be performed in a different order. In some
procedures it may not be necessary to insert transverse elements at
both the first and second positions. For example, it may be
possible to develop sufficient compression between the head of the
screw and one or more transverse elements located on the screw
threads that a transverse element near the head of the screw is not
needed. Alternatively, it may be possible to develop sufficient
compression between the screw threads and a transverse element
mounted near the screw head that one or more transverse elements
mounted on the screw threads are not needed. When transverse
elements are used at both the first and second positions, the holes
can be drilled at the second position before they are drilled at
the first position; or it may not be necessary to drill the holes
at one or both positions because it may be possible to insert the
transverse elements at the appropriate positions around the screw
using other devices. Similarly, it may not be necessary to use the
osteotome at one or both positions.
* * * * *