U.S. patent application number 13/771646 was filed with the patent office on 2016-06-09 for method and apparatus for repairing the mid-foot region via an intramedullary nail.
The applicant listed for this patent is Howmedica Osteonics Corp.. Invention is credited to William H. Simon.
Application Number | 20160157900 13/771646 |
Document ID | / |
Family ID | 31715843 |
Filed Date | 2016-06-09 |
United States Patent
Application |
20160157900 |
Kind Code |
A1 |
Simon; William H. |
June 9, 2016 |
Method and Apparatus for Repairing the Mid-Foot Region Via an
Intramedullary Nail
Abstract
A device, method, and system for treatment or fixation of a
fractured, damaged, or deteriorating bone or bones in a mid-foot
region. The device comprising an implant with both proximal and
distal fastener holes, along with fastener slots in a central
elongated body, for securing the implant to the appropriate osseous
cortical structures of the foot. The method for treatment or
fixation of fractured, damaged, or deteriorating bones in the
medial column of the foot with use of a device such as an
intramedullary nail that attaches to either the talus or first
metatarsal bones to secure the medial cuneiform and navicular bones
in place.
Inventors: |
Simon; William H.; (Virginia
Beach, VA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Howmedica Osteonics Corp. |
Mahwah |
NJ |
US |
|
|
Family ID: |
31715843 |
Appl. No.: |
13/771646 |
Filed: |
February 20, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13596987 |
Aug 28, 2012 |
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13771646 |
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Current U.S.
Class: |
606/62 |
Current CPC
Class: |
A61B 17/7233 20130101;
A61B 17/7241 20130101; A61B 17/7225 20130101; A61B 17/7291
20130101; A61B 17/72 20130101; A61B 2017/681 20130101; A61B 17/846
20130101; A61B 17/8897 20130101; A61B 17/7216 20130101 |
International
Class: |
A61B 17/72 20060101
A61B017/72 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 1, 2003 |
CA |
2495110 |
Mar 7, 2005 |
EP |
03749001.8 |
Claims
1. A device for treatment or fixation of a fractured, damaged or
deteriorating bone or bones in a mid-foot region, said device
having a proximal end, a distal end, and a central elongated body,
said device comprising an attaching means to a bone or bones of a
foot such that said attaching means secures said mid-foot
region.
2. A device as in claim 1, wherein said bone or bones of said
mid-foot comprises: a) a first metatarsal bone, b) a talus bone, c)
a medial cuneiform bone, and d) a navicular bone.
3. A device as in claim 1, wherein said device is an implant which
is inserted into a medullary canal of said first metatarsal bone,
said medial cuneiform bone, said navicular, and said talus
bone.
4. A device as in claim 1, wherein said implant is an
intramedullary nail.
5. A device as in claim 1, wherein said intramedullary nail is
cannulated comprising a round cross-section with said central
elongated body.
6. A device as in claim 1, wherein said intramedullary nail is
adapted with said attaching means by way of a proximal fastener
hole and a distal fastener hole to allow for compression of said
mid-foot region.
7. A device as in claim 1, wherein said attaching means is
accomplished by insertion of at least one fastener in at least one
fastener hole or slot at either said proximal end, said distal end,
or said central body of said implant.
8. A device as in claim 1, wherein said attaching means utilizes at
least one proximal fastener hole and at least one distal fastener
hole which allows for reduction and compression of said mid-foot
region.
9. A device as in claim 1, wherein said fastener is configured and
dimensioned for insertion in at least one said fastener hole,
further comprising a threaded hole for insertion of a screw, said
screw having an optional threaded head portion and a threaded shaft
portion.
10. A method for treating or fixation of a fractured, damaged or
deteriorating bone or bones in a mid-foot region comprising the
steps of: (a) providing an implant sized to span a length from a
patient's first metatarsal bone to a patient's talus bone, said
implant having a proximal end, a distal end, and a central
elongated body, wherein said central elongated body provides
support for said mid-foot region; (b) reaming of a medullary canal
of a first metatarsal bone, a medial cuneiform bone, a navicular
bone, and a talus bone; (c) inserting said implant into said
medullary canal of said first metatarsal, medial cuneiform,
navicular, and talus bones; (d) securing said implant by inserting
at least one fastener through both a fastener hole or slot of said
implant device, and into either said first metatarsal bone, said
medial cuneiform bone, said navicular, or said talus bone.
11. The method of claim 10, wherein additional steps comprise: a)
preceding the step of providing said implant, further comprising a
taking of at least one x-ray picture for determining said sized
span of said implant, wherein said taking of said x-ray picture is
optional; b) following the step of providing said implant,
dislocating of a patient's phalanges bone or bones from said first
metatarsal bone; c) following the step of dislocating of said
phalanges bone, performing an arthrotomy of said first metatarsal;
d) following the step of performing said arthrotomy, removing a
plug of bone from a patient's head of said first metatarsal bone,
using a tubular chisel system, wherein removing said plug of bone
is optional; e) following of either the step of performing said
arthrotomy or the step of removing said plug of bone, accomplishing
closed reduction of said bone or bones of said mid-foot region,
wherein said reduction may be limited to said medial cuneiform and
said navicular bones; f) following the step of accomplishing said
closed reduction, inserting a guide-wire through said medullary
canal of said first metatarsal medial cuneiform, navicular, and
talus bones, wherein said guide-wire may be a smooth guide-wire or
a ball tip guide-wire, said ball tip guide wire may used for
removing a reaming device; g) following the step of inserting of
either said guide-wires, the step of said reaming of said medullary
canal, wherein said reaming performed over either of said
guide-wires; h) following the step of said reaming, inserting of
said smooth guide-wire; i) following the step of inserting of said
smooth guide-wire, attaching of said implant to a jig apparatus
with an outrigger prior to the step of inserting of said implant
into said medullary canal; j) further comprising the step of
securing said implant, securing of said proximal end is
accomplished by inserting at least one said fastener through said
fastener hole or slot of said implant into said first metatarsal
bone; k) following the step of securing said proximal end,
compressing of said bone or bones in said mid-foot region, wherein
said compressing is optional; l) following either the step of
compressing or the step of securing said proximal end, and further
comprising the step of securing said implant, securing of said
distal end is accomplished by inserting at least one said fastener
through said fastener hole or slot of said implant into said first
metatarsal, wherein said securing of said distal end is optional;
m) following the step of securing said distal end, replacing of
said plug of bone is performed only if said step of removing of
said plug of bone was performed; n) following either the step of
replacement of said plug or the step of securing said distal end,
relocation of said phalanges to said first metatarsal is performed,
followed by suturing of all incision sites.
12. The method of claim 10, wherein performing steps (e)-(h) may be
accomplished under fluoroscopy.
13. The method of claim 10, wherein said step of insertion of said
implant is performed under fluoroscopy, over said smooth
guide-wire.
14. The method of claim 10, wherein the step of securing said
implant by inserting at least one fastener may be placed
percutaneously.
15. The method of claim 10, wherein the step of compression may be
accomplished by using an in-line compression sleeve implant.
16. The method of claim 10, wherein the step of compression may be
accomplished by determining the amount of compression applied with
use of a depth gauge, said depth gauge may be a part of either said
jig apparatus or said implant, wherein said depth gauge measures an
amount of travel of said implant back up said medullary canal
towards a point of insertion of said implant.
17. The method as in anyone of claim 10, wherein said implant is an
intramedullary nail.
18. A system for treating deteriorating bones in a mid-foot region
comprising: a) A device for treatment or fixation of a fractured,
damaged or deteriorating bone or bones in a mid-foot region, said
device having a proximal end, a distal end, and a central elongated
body, said device comprising an attaching means to a bone or bones
of a foot such that said attaching means secures said midfoot
region. b) A method for treating or fixation of a fractured,
damaged or deteriorating bone or bones in a mid-foot region
comprising the steps of: c) providing an implant sized to span a
length from a patient's first metatarsal bone to a patient's talus
bone, said implant having a proximal end, a distal end, and a
central elongated body, wherein said central elongated provides
support for said mid-foot region; d) reaming of a medullary canal
of a first metatarsal bone, a medial cuneiform bone, a navicular
bone, and a talus bone; e) inserting said implant into said
medullary canal of said first metatarsal, medial cuneiform,
navicular, and talus bones; f) securing said implant by inserting
at least one fastener through both a fastener hole or slot of said
implant device, and into either said first metatarsal bone, said
medial cuneiform bone, said navicular, or said talus bone.
19. A system as in claim 18 wherein additional steps comprise: a)
preceding the step of providing said implant, further comprising a
taking of at least one x-ray picture for determining said sized
span of said implant, wherein said taking of said x-ray picture is
optional; b) following the step of providing said implant,
dislocating of a patient's phalanges bone or bones from said first
metatarsal bone; c) following the step of dislocating of said
phalanges bone, performing an arthrotomy of said first metatarsal
is performed; d) following the step of performing said arthrotomy,
removing a plug of bone from a patient's head of said first
metatarsal bone, using a tubular chisel system, wherein removing
said plug of bone is optional; e) following of either the step of
performing said arthrotomy or the step of removing said plug of
bone, accomplishing closed reduction of said bone or bones of said
mid-foot region, wherein said reduction may be limited to said
medial cuneiform and said navicular bones; f) following the step of
accomplishing said closed reduction, inserting a guide-wire through
said medullary canal of said first metatarsal, medial cuneiform,
navicular, and talus bones, wherein said guide-wire may be a smooth
guide-wire or a ball tip guide-wire, said ball tip guide wire may
used for removing a reaming device; g) following the step of
inserting of either said guide-wires, the step of said reaming of
said medullary canal, wherein said reaming performed over either of
said guide-wires; h) following the step of said reaming, inserting
of said smooth guide-wire; i) following the step of inserting of
said smooth guide-wire, attaching of said implant to a jig
apparatus with an outrigger prior to the step of inserting of said
implant into said medullary canal; j) further comprising the step
of securing said implant, securing of said proximal end is implant
into said first metatarsal bone; k) following the step of securing
said proximal end, compressing of said bone or bones in said
mid-foot region, wherein said compressing is optional; l) following
either the step of compressing or the step of securing said
proximal end, and further comprising the step of securing said
implant, securing of said distal end is accomplished by inserting
at least one said fastener through said fastener hole or slot of
said implant into said first metatarsal, wherein said securing of
said distal end is optional; m) following the step of securing said
distal end, replacing of said plug of bone is performed only if
said step of removing of said plug of bone was performed; n)
following either the step of replacement of said plug or the step
of securing said distal end, relocation of said phalanges to said
first metatarsal is performed, followed by suturing of all incision
sites.
20. A system as in claim 18, comprising a medical procedure which
may require an overnight hospital or medical facility stay, or
comprising an out-patient procedure.
Description
PRIORITY
[0001] Applicant hereby claim priority under all rights to which
they are entitled per 35 USC 120 based upon the U.S. Application
No. 60/402,380 for this Patent Cooperation Treaty (PCT) patent
application (USPTO receiving office) filed at the United States
Patent and Trademark Office on Aug. 10, 2002. This application also
takes priority from PCT/US2003/024185 entitled, "Method and
Apparatus for Repairing the Mid-Foot Region Via an Intramedullary
Nail", filed on Aug. 1, 2003 and its corresponding US National
Stage application under 35 USC 371, Ser. No. 10/525,544 of the same
title and filed Jan. 28, 2005. Priority is also claimed to the
corresponding continuation application Ser. No. 13/593,987 of the
same title filed on Aug. 24, 2012. The entire contents of the above
referenced applications are also herewith incorporated by
reference, in their entirety, in the present application.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The field of the present invention relates to a method and
apparatus for repairing damaged, deteriorating, or fractured bones
in the mid-foot region. More particularly, the present invention
relates to both a method and device for treating the bones in the
medial column of a human foot that are effected by Diabetic Charcot
mid-foot collapse, LisFranc injuries, and the like.
[0004] 2. Description of Related Art
[0005] The utilization of implants, such as intramedullary nails,
rods, and screws is well known in the art, specifically in the
treatment of long or large bone fractures. Implants are those
devices which may be inserted into any foreign body, with
intramedullary nails being the most common type of implant.
Intramedullary nails have been limited in their application to long
or large bones and such use has been widely known for long or large
bones of the upper extremities (humerus, radius, ulna) and lower
extremities (femur, tibia, fibula). Use of intramedullary nails
allows physicians to secure fractured bones, maintain a desired
length, and prohibit rotary motion while the bone heals and has
time to rehabilitate. Intramedullary nails are also used for the
fusion of bones.
[0006] Intramedullary nails are adapted for insertion into the
medullary canal of a bone or bones, which may be reamed or left
unreamed. Reaming is achieved by drilling out the medullary canal
of the fractured or deteriorating bone, where the nail is inserted
to stabilize and position the bone for healing. A cannulated reamer
diameter generally runs in size from 7 mm and 18 mm, at increments
of 0.5 mm. A medullary canal is generally reamed at 0.5 mm larger
than the diameter of the nail to be inserted, so the bone is not
damaged when the nail is inserted. Such reamers are well known by
those with skill in the art.
[0007] Much of the prior art implant and intramedullary nail
systems comprise intramedullary nails having fastener holes at both
the proximal and distal ends for the insertion of fasteners, or
locking screws. Fasteners include all attaching means by which an
implant may be attached to bone. Such fasteners are inserted
through a fastener hole or slot, also described as transfixation
holes and screw holes. The use of locking screws is optional
depending upon the severity of the bone damage. An intramedullary
nail implanted with at least one fastener or locking screw both
proximally and distally completely locks the nail in place (also
known as static locking). Static locking neutralizes rotational
stresses while preventing shortening of the limb. An intramedullary
nail implanted with only one locking screw either proximally and
distally, partially locks the nail (also known as dynamic locking).
Dynamic locking neutralizes rotational stresses on one side of the
fracture site while permitting axial loading. To surgically promote
fusion of bone segments together, some means of static locking is
required. Such holes and screws may also be adapted for the central
portion of the nail or implant.
[0008] Several nails exist with fasteners or locking screws that
are much longer in shape, described as lag screws, jigs, or nail
heads, which further prevent the rotation of separated bones. Other
nails have spacers to absorb stress associated with repetitive,
natural impact. All such devices are focused on securing bone
fragments during the process of fracture healing. Other methods for
attaching the nail to the bone including the use of longitudinal
pins, or the use of cement injected through a cannula in a nail to
secure one end to the nail.
[0009] Various types of implants and intramedullary nails exist in
the prior art, each composed of different materials and having
different shapes with various degrees of functionality. Many nails
are formed from either a slid rod metal or a more flexible sheet
metal. Several nails have been proposed which form a rod material
containing a central longitudinal bore disposed throughout
(cannulated). Many nails have a number of longitudinal grooves cut
along the rod (known as fluting), which allow for more rapid
revascularization within the bone. Accordingly, nails made of
various material and those having a differing array of shapes
already exist and may be easily manufactured. A study of the
geometrical properties of different nails is discussed in the
article "Geometrical Properties and Torsional Fatigue Life of a
Tibial Interlocking Intramedullary Nail Segment" Journal of
Orthapedic Trauma, Vol. 12, No. 1, pp 8-15, and is incorporated
herein. Also, different tibial nails were compared in the article
"Biomechanical Study of Nine Different Tibia Locking Nails" Journal
of Orthapedic Trauma, Vol. 10, No. I, pp 37-44, which is also
incorporated herein.
[0010] Recently, implants and intramedullary nails are being
fabricated using bioactive, biocompatible, and bioabsorbable
material. Such nails are made from bioabsorbable polymers,
copolymers, or polymer alloys that are self-reinforced containing
ceramic particles or some type of reinforcement fibers. These
implants and nails, as well as others, can also be made to be
porous. The knowledge exists today to create human replica bones,
grown in animals utilizing human gene technology, for ultimate use
in humans, and such material may be a viable supplement for
standard intramedullary nails of today. Such techniques should also
be considered as an appropriate part of the present invention.
[0011] While there is much in the art regarding implants and
intramedullary nails, there was no prior art found dealing directly
with implants or intramedullary nails for the mid-foot region, or
medial column of a human foot. Such a nail may likely have any or
all of the similar properties, features, and characteristics of the
above mentioned nails, but would have to be much smaller in length
and thickness (for axial support) to accommodate the smaller bones
of the mid-foot region. The prior art referring to intramedullary
nails, for the most part, refers to nails which are used in much
larger bones. Such art includes:
[0012] WO 00/72767 AI. The application describes an intramedullary
nail for insertion within an intramedullary canal of a long bone
and fixing a fracture in the long bone.
[0013] The nail comprises an elongate member with longitudinal
axis, proximal and distal end, both of which have fastener
receiving areas of at least one hole.
[0014] U.S. Pat. No. 6,406,477. The patent describes an
intramedullary nail with a lag screw for connecting a bone portion
separated from the femur, by fracture, to the main portion of the
bone where such nail is capable of extending through both portions
where a lag screw secures the nail.
[0015] WO 02/34107 A2. The Application describes an internal
fixation device which utilizes a shaft within a sleeve wherein the
shaft is movable within the sleeve along aligned slots.
[0016] U.S. Pat. No. 6,270,499 B1. The patent describes an
intramedullary nail where the proximal end has at least one bore
which extends transversely to the central axis of the nail for
receiving at a stable angle a bone fastener.
[0017] U.S. Pat. No. 6,406,498 BI. The patent describes a device,
such as an intramedullary nail or the like, which is fabricated
using bioactive, biocompatible, and/or bioabsorbable material.
[0018] U.S. Patent Application No. US 2002/0029041 AI. The
application describing an intramedullary nail formed with opposing
dynamization windows and spacers of nonmetal material positioned
within the windows to absorb stress transmitted through a fracture
site.
[0019] U.S. Pat. No. 6,120,504. The patent describes an
intramedullary nail with a longitudinal centerline extending
between a proximal and distal end. The invention is directed to be
interchangeably used in either a right or left limb, and to thus
reduce the number of nail that must be inventoried at hospitals and
other places utilizing intramedullary nails.
[0020] U.S. Pat. No. 4,705,027. The patent describes an
intramedullary nail having a slot at the tip of the nail for
engaging within the slot, a bolt previously inserted into the
bone.
[0021] U.S. Pat. No. 5,658,287. The patent describes a locked
intramedullary nail suitable for treating fractures of the
femur.
[0022] U.S. Pat. No. 5,034,013. The patent describes an
intramedullary nail having a tubular elongated body with grooves
along the elongated body to allow for improved revascularization
about the nail.
[0023] U.S. Pat. No. 5,766,174. The patent describes an
intramedullary nail with an arcuate terminus tip, transverse holes
for receiving fixation screws, and suture holes for the attachment
of tissue.
[0024] U.S. Pat. No. 5,336,225. The patent describes device for
reducing fractures, comprising a threaded screw.
[0025] U.S. Pat. No. 6,123,708. The patent describes a nail for
axial insertion into a bone for support comprising a central bore
through the nail body and a plurality of transverse holes
throughout.
[0026] U.S. Pat. No. 5,814,047. The patent describes an
intramedullary nail fixation apparatus having a plurality of
equiangularly spaced piercing points.
[0027] U.S. Pat. No. 5,855,579. The patent describes a modular
intramedullary nail having an open ended longitudinal bore, with
connectable ends for elongating the nail.
[0028] E.P. 1 095626 AI. The patent describes a radial
intramedullary nail.
[0029] U.S. Pat. No. 5,620,445. The patent describes a modular
intramedullary nail with proximate, distal, and central
components.
[0030] There is no known prior art relative to the use of
intramedullary nails in the treatment of mid-foot bones or more
specifically, treating the bones of the medial column. Most of the
prior art describing the use of intramedullary nails is limited to
methods for repairing large bones including, but not limited to the
humerus, radius, ulna, femur, tibia, and fibula. Such art
includes:
[0031] U.S. Pat. No. 6,019,761. The patent describes an
intramedullary nail for implanting within a patient's long bone,
and a method of use.
[0032] U.S. Pat. No. 5,201,735. The patent describes an apparatus
such as a bone implant and method for implanting a bone implant or
intramedullary rod for fixing a fracture of a bone.
[0033] U.S. Pat. No. 5,935,127. The patent describes a method for
treating a fracture in a long bone by utilizing either a plate or
intramedullary nail that spans the length of the bone.
[0034] U.S. Pat. No. 5,919,193. The patent describes a method for
surgically correcting malformations in digits of a finger or toe by
way of a one piece bone screw.
[0035] U.S. Pat. No. 4,976,712. The patent describes a method and
apparatus for treating fractured bones by way of a bone screw.
[0036] The prior art relative to current treatments of mid-foot
deformities, particularly those analogous to this type of
treatment, are limited to:
[0037] "Charcot Ankle Fusion with a Retrograde Locked
Intramedullary Nail" Foot & Ankle International, Vol. 18, No.
11, November 1997. This article focuses primarily on ankle fusion
with a locked intramedullary nail, but specifies mid-foot deformity
treatment to be limited to patient education, local foot-care,
accommodative shoe gear, custom foot orthoses, and surgical
correction.
[0038] Additional articles of significance include; "Surgical
Reconstruction of the Diabetic Foot: A salvage approach for
mid-foot collapse" Foot Ankle Int., Early, J. S. and Hansen, S. T.,
17:325-330, 1996 and "Arthrodesis as an Early Alternative to
Nonoperative Management of Charcot Arthopathy of the Diabetic
Foot", The Journal of Bone and Joint Surgery, Inc., S. R. Simon Et
AI., Vol. 82-A, No. 7, July 2000.
[0039] "The Lateral Column Lengthening and Medial Column
Stabilization Procedures" Clinical Orthopedics and Related
Research, T. D. Chi Et al., No. 303, August 1999. Is an article
that is the closest related study of surgical repair procedures to
the present invention; however, it describes the use of multiple
screws to secure the bones within the mid-foot which produced
severely limited results.
SUMMARY OF THE INVENTION
[0040] The present invention is directed to a device and method for
treating and fixation of deteriorating, damaged, or fractured bones
in the mid-foot region (navicular, medial cuneiform, intermediate
cuneiform, lateral cuneiform and cuboid bones). More specifically,
the present invention relates to the treatment and fixation of
certain bones in the medial column (specifically, the medial
cuneiform and navicular bones) of a human foot. Such bones are not
considered long or large in the traditional sense as are those
specified above. An apparatus, such as an implant, or more
specifically an intramedullary nail, is inserted through and
attached to both the first metatarsal and talus bones to secure the
medial cuneiform and navicular bones in place. This procedure also
is expected stabilize all the bones in the mid-foot region. After
appropriate reduction and compression, such a method and device
would ultimately allow for fusion of the bones. In accordance with
the present invention, one device used to achieve the above
described method is a cannulated intramedullary nail that is round
in cross-section, having an elongated body with a proximal head
portion, intermediate portion, and distal tapered end portion. The
proximal head portion has one or more transverse holes, ideally
three, with an intermediate portion having one or more transverse
slots, ideally two, and a distal portion having one of more
transverse holes, ideally two. Such transverse fastener holes or
slots are used for insertion of fasteners (including interlocking
cortical screws or transfixation screws), which ideally may be
attached to the first metatarsal and talus bones to secure the nail
in place. Slots are adapted for the central portion of the nail for
the insertion of fasteners into either the navicular or medial
cuneiform, depending upon the condition of either of the two
bones.
[0041] One object of the present invention is to provide an implant
or intramedullary nail for the treatment and fixation of those
bones within the mid-foot that are subject to damage,
deterioration, or fracture that may result from diabetes related
diseases, including but not limited to, Charcot foot. More than 16
million Americans have diabetes, of which approximately 54,000
patients underwent lower extremity amputations in 1990. The
five-year mortality rate for diabetics has been reported as high as
70%. Approximately 800,000 Americans develop diabetes annually. The
cost of caring for diabetes now exceeds $137 billion per year, or
approximately 30% of the annual Medicare budget. Diabetic
neuropathy ultimately results in deterioration of the bones in the
foot. Such deterioration of those bones in the mid-foot region
leads to the collapse of the foot, fracture of those bones, or
both. The prevalence of Diabetic Charcot joints has been reported
to be from 0.08% to 7.5%. The average age of onset is approximately
57 years with the majority of patients in their sixth and seventh
decades. The average duration of diabetes with a diagnosis of
Charcot arthropathy is 15 years, with 80% of the patents being
diabetic for more than 10 years. Bilateral Charcot arthropathy has
been reported between 5.9% to 39.9%. Incidence of Diabetic Charcot
arthropathy appears equally among men and women.
[0042] Diabetic foot treatment to date has been limited to
amputation, special casts or shoes which alleviate the deformity,
and surgical intervention to strengthen the foot. An article
describing an overview of diabetic foot problems is "Diabetic
Neuropathic Osteoarthropathy: The Charcot Fool" Chapter 16 of The
High Risk Foot in Diabetes Mellitus, edited by R. G. Frykberg,
.COPYRGT. Churchhill Livingstone Inc., 1991, and is incorporated
herein. Amputation of the opposite extremity is frequently
indicated within one to five years of the primary amputation.
Surgical intervention has been restricted to the use of screws and
plates since most bones in the foot are quite small. Methods used
to repair larger bones with devices such as intramedullary nails
have not been utilized in this area until now.
[0043] The medial column of the foot is comprised of six osseous
components (distal phalanx, proximal phalanx, first metatarsal,
medial cuneiform, navicular, and talus). The longitudinal arch of
the foot is maintained by these bone segments and their supporting
ligaments, tendons, and surrounding musculature. Additional support
comes from the transverse arch and the interlocking of the osseous
components. The medial column of the foot is the most commonly
affected in the diabetic by sympathectomy-induced hyperemia
associated with repetitive minor trauma resulting in mid-foot
dislocations and/or fractures known as Diabetic Charcot
deformities.
[0044] Treatment of foot and ankle Charcot deformities currently
consists of nonsurgical (non-contact casting, orthotic bracing, and
shoe gear) and surgical stabilization (k-wires, screw/plate
fixation, and external fixators). Recently, implant and
intramedullary nail fixation has been utilized to stabilize the
ankle/subtalar joint complex. Present treatment for medical
column/mid-foot deformities requires extensive surgical exposure
with appropriate internal screw/plate fixation devices. One
advantage of using an implant or intramedullary nail for treatment
and fixation of these bones, is the limited surgical exposure that
is required with only several small incisions, as opposed to the
more invasive exposure resulting from opening the entire foot for
insertion of several internal screws and plate devices. Also, the
successes of screw and plate fixation is minimal at best.
[0045] Although prior art nails have found varying degrees of
success in the treatment of long bone fractures and hind-foot
arthrodesis, there remains a need in the field for an
intramedullary nail specific for fixation of the medial column of
the foot. This device will substantially reduce, if not eliminate
many of the present complications encountered with Diabetic Charcot
foot reconstruction. Such a device would provide fixation and
stabilization of the Diabetic Charcot foot preventing future
mid-foot collapse and ultimate limb loss. An intramedullary medial
column nail and method of utilization would provide stabilization
to the medial column of the foot, eliminating excessive operating
time, anesthesia exposure, implant failure, long hospital stays,
and reduce overall medical cost leading to early rehabilitation and
ultimately limb salvage.
[0046] The present invention specifically relates to the fusion,
and eventual rejuvenation of the bones in the mid-foot region which
deteriorate because of diabetic neuropathy. The method comprises
insertion of an implant or intramedullary nail through the medial
cuneiform and navicular bones, which are most susceptible to
deterioration, and securing the nail with locking screws to the
stable first metatarsal and talus bones. This is one method for
securing, fusing, and repairing the medial cuneiform and navicular
bones and represents one embodiment of the present invention.
[0047] The present invention utilizes an intramedullary medial
column nail fixation apparatus ideally being cylindrical and
cannulated, and made from either titanium, a bioabsorbable
material, human or animal bone, or equivalent. The nail ideally
would have a number of proximal and distal fastener holes
(transfixation or interlocking holes) for securing the IM medial
column nail to the appropriate osseous cortical structures of the
foot. An important feature of the present invention of the IM nail
is its ability to function as an internal load-sharing device along
the medial column of the foot. The nail acts as an internal
splintage while the bones are mending, and is used to bring into
alignment microfractures that may exist. The proximal portion of
the nail may have a tapered tip to aid in insertion, and at least
one fastener hole (ideally two) for the insertion of fasteners to
fixate the neck of the talus to the implant or nail. The
intermediate portion ideally has two slots to accommodate for any
bone loss of the navicular and medial cuneiform, and to allow for
the possible insertion of a fastener if the bones are healthy
enough. The distal portion has at least one fastener hole (ideally
three) for the insertion of fasteners to fixate the nail to the
first metatarsal.
[0048] The present invention may also make use of a specialized
thin walled tubular chisel system for removal of first metatarsal
head articular cartilage for nail insertion. 30 This maintains the
integrity of the first metatarsal head by removing only an
appropriate sized plug of bone according to the diameter of nail
being used. The plug of articular cartilage and underlying bone can
then be replaced and fixated after insertion of the nail. Such a
chisel system may be similar to one that has been used in
osteochonral autograph transfer.
[0049] In addition, another embodiment of the present invention
calls for the use of a compression system that incorporates a depth
gauge device which may be used to determine the amount of
compression achieved. This device would eliminate the need for
guessing or "feeling" the correct amount of compression required. A
depth gauge would exist either on the implant or jig apparatus with
a ruler type measuring means for gauging the amount of travel in
the nail back up the intramedullary canal towards the phalanges.
Compression could then be determined to a specified length of
travel of the nail back up the canal during compression.
BRIEF DESCRIPTION OF DRAWINGS
[0050] FIG. 1 is a top down skeletal outline of a right human foot
with an implant located within.
[0051] FIG. 2 is a side skeletal outline of a left human foot with
an implant located within.
[0052] FIG. 3 is an x-ray picture taken following an experimental
procedure to insert an implant into a patient's foot.
DETAILED DESCRIPTION OF EMBODIMENTS
[0053] The following description will explain the embodiments of
the invention, beginning with a device used for treating
deteriorating or damaged bones in the medial column of a human
foot, and concluding with the method for treating deteriorating or
damaged bones in the medial column of a human foot. Both the first
and second figures are skeletal outlines of a human foot, depicting
the device therein and the resulting orientation of the bones by
using the method specified below.
[0054] FIG. 1 is a top down view of a right human foot, depicting
the bones therein and an implant or intramedullary nail 10 running
through the mid-foot region. The implant or intramedullary nail 10
runs through the medullary canal of first metatarsal 7, medial
cuneiform 3, navicular 2, and talus bone 1. The talus bone 1 makes
up the lower part 20 of the ankle joint where the proximal end 11
of the implant or intramedullary nail 10 is attached with at least
one fastener (or locking screw, with two depicted in FIGS. 1, 14
& 15). Next to the talus bone, opposite the rest of the ankle
bones, are the tarsal bones which include the navicular 2, medial
cuneiform 3, intermediate cuneiform 4, lateral cuneiform 5, and
cuboid bones 6.
[0055] The medial cuneiform 3 and navicular 2 bones are those most
affected by the Diabetic Charcot foot disorder, which causes
deterioration and possible collapse as a result of the mechanics
behind the foot and the amount of weight they are responsible for.
These are the bones that the present invention focuses on fixation
and stabilizing for rejuvenation, and insertion of an implant or
intramedullary nail 10 through them as an embodiment of the
invention. If either of the two bones are stable enough to support
a locking screw, the nail is designed to have holes for that
purpose, a first fastener hole 16 for the navicular bone 2 and a
second fastener hole 17 for the medial cuneiform 3. These two
fastener holes transverse the axial central axis (central elongated
body) 13 of the nail. Finally, the first metatarsal 7 is the bone
that makes up the big toe in the human foot, where the distal end
12 of the intramedullary nail 10 is attached by way of at least one
fastener (or locking screw, with three depicted in FIGS. 1,20, 19,
& 18).
[0056] FIG. 2 is a side view of a left human foot, depicting the
bones therein and an implant or intramedullary nail 10 running
through the mid-foot region. Again, the implant or intramedullary
nail 10 runs through the medullary canal of first metatarsal 7,
medial cuneiform 3, navicular 2, and talus bone 1. This figure
shows the phalanges bones (8 & 9) which are joined to the first
metatarsal 7, at which the joint must be dislocated downward (as
will be discussed below) prior to insertion of the intramedullary
nail 10. Again, the nail's proximate end 11 is inserted up into the
talus bone 1 far enough so that at least one proximal fastener
holes (14 & 15 depicted) are within the bone.
[0057] The nail 10, being one embodiment of the present invention,
must be sized (length and diameter) so that it extends far enough
into the talus bone 1 to clear at least one fastener hole, and
include fastener holes for the proper attachment of fasteners
(locking screws) in the remaining bones, at least one fastener hole
(with three depicted in the FIGS. 20,19, & 18) for attaching
and locking the nail to the first metatarsal 7, and optionally, a
first fastener hole 16 for the navicular bone 2 and a second
fastener hole 17 for the medial cuneiform 3.
[0058] A second embodiment of the present invention is the method
by which a device (such as an intramedullary nail as depicted in
FIG. 1 & FIG. 2) may be used and inserted into and through the
mid-foot region to support damaged or deteriorating bones therein.
The first step would consist of the taking of x-ray pictures of the
unhealthy foot to determine the extent of the injury, and the size
(length and diameter) of the device or implant (herein,
intramedullary nail 10, as depicted in FIG. 1 & FIG. 2) needed
for insertion. Second, dislocation of the phalanges 8 which are
attached to the first metatarsal must be done to expose the head of
the first metatarsal. Third, an arthrotomy of the first metatarsal
7 is done. Fourth, as an optional embodiment of the present
invention, a tubular chisel system may be used to remove a plug of
bone and cartilage from the underlying head of the first metatarsal
(which can then be re-plugged after insertion of the nail to more
rapidly promote healing and not leave a gap in the head of the bone
as one skilled in the art would recognize). Fifth, closed reduction
is performed on the bones in the mid-foot region which may be
sagging or close to collapse as a result of deterioration or
fracture. Sixth, a guide-wire is inserted through the medullary
canal of first metatarsal 7, medial cuneiform 3, navicular 2, all
the way into the talus 1 with use of fluoroscopy to maintain
correct alignment of the foot. The first guide-wire may have a ball
tip on the end to make sure the flexible reamer may be easily
removed if it breaks. The seventh step consists of reaming over the
guide-wire with the ball tip all the way into the talus 1. The
reaming is done under fluoroscopy so that the correct depth into
the talus 1 may be achieved. Reaming should be done at 0.5 mm
diameter larger than the nail to be inserted. The eighth step
consists of placing the appropriate sized nail into a jig apparatus
with outrigger, and then inserting the nail into the first
metatarsal 7, by running over a smooth guide-wire. The nail is
centered into the medullary canal beginning with the first
metatarsal 7, and then through the medial cuneiform 3, navicular 2,
and talus 1 bones respectively. Ninth, at least one fastener (or
locking screw, with two depicted in FIGS. 1, 14 & 15) is placed
percutaneously into the proximal fastener hole of the nail, and
into the talus bone. This procedure only requires a small stab
incision, that which one "skilled in the art" would appreciate. The
tenth step, is an optional step of compression that may be achieved
with a nail of the type having a trocar and sleeve mechanism known
in the art, or the like. A further embodiment of the present
invention could include a depth gauge device which may be used to
determine the amount of compression achieved, that which is
determined by the width of the bone. This device would eliminate
the need for guessing the correct amount of compression required,
since the amount of compression could then be determined to a
specific length of travel of the nail back up the canal. An in-line
compression sleeve may be one means used to afford compression upon
the bones in the mid-foot region. After adequate compression is
achieved (that which would be known by those skilled in the art),
the eleventh step involves insertion of at least one fastener (or
locking screw, with three depicted in FIGS. 1,20, 19, & 18)
into the distal fastener hole(s) and also into the first
metatarsal. The same process of percutaneously inserting the
fasteners as noted above for the proximal end can be replicated
here. Fasteners may be optionally included in slots 16 for the
navicular bone 2 and 17 for the medial cuneiform 3, depending upon
the condition of either of these two bones. The twelfth step
consists of removing the jig and replacing the plug of bone
previously removed (if such step was utilized). The joint is then
reduced (relocated) and the joint capsule is repaired and the sites
are all sutured.
[0059] FIG. 3 is an x-ray picture taken following an experimental
procedure to insert an implant into a patient's foot with two
fasteners at both the proximal and distal ends. The procedure,
performed in March of 2000, is being followed-up to determine the
effectiveness of the newly adapted treatment. This is the only
procedure to date ever performed of its kind. Such a procedure is
an embodiment of the present invention.
[0060] The implant was a small intramedullary (Smith & Nephew)
nail intended for insertion in a longer bone. The fasteners were
locking screws inserted into the transfixation holes and also into
the talus and first metatarsal bones. Such a device is an
embodiment of the present invention.
* * * * *