U.S. patent application number 10/992746 was filed with the patent office on 2006-05-25 for minimally invasive facet joint hemi-arthroplasty.
This patent application is currently assigned to Orthopedic Development Corporation. Invention is credited to David Ari Petersen.
Application Number | 20060111780 10/992746 |
Document ID | / |
Family ID | 36461925 |
Filed Date | 2006-05-25 |
United States Patent
Application |
20060111780 |
Kind Code |
A1 |
Petersen; David Ari |
May 25, 2006 |
Minimally invasive facet joint hemi-arthroplasty
Abstract
A minimally invasive facet joint hemi-arthroplasty method using
a unique metallic overlay, instrumentation and surgical protocol to
resurface the superior facet of the inferior vertebrae limited to
the facet joints located on the lumbar spine, Occiput-C1 through
L5-S1. Using related new instrumentation and a surgical protocol
invented to prepare the joint, a metallic overlay is mechanically
crimped in place without the use of cement or pedicle screws.
Permanent fixation occurs when bone in-grows onto a rough, porous
surface on the inside of the implant. This hemi-arthroplasty method
resurfaces half of the facet joint to provide for smooth, pain free
joint articulation in deteriorated or diseased spinal facet joints
without the need for major surgery or rehabilitation at
considerably less risk to the patient. This procedure may also be
used to prophylactically resurface the joint to minimize or
eliminate future deterioration caused by the additional stress to
facet joints from disc replacements or instrumented vertebral
fusion. Instrumentation includes a newly invented planer, director
probe with slap-hammer, vertebral separator, osteotome, broach,
crimper and facet joint prosthetic implant for use in surgically
resurfacing facet joints located from Occiput-C1 through L5-S1
using a minimally invasive outpatient facet joint hemi-arthroplasty
method developed specifically for that purpose.
Inventors: |
Petersen; David Ari; (Indian
Rocks Beach, FL) |
Correspondence
Address: |
Herbert W. Larson;Larson & Larson, P.A.
11199-69th Street North
Largo
FL
33773
US
|
Assignee: |
Orthopedic Development
Corporation
Clearwater
FL
|
Family ID: |
36461925 |
Appl. No.: |
10/992746 |
Filed: |
November 22, 2004 |
Current U.S.
Class: |
623/17.11 |
Current CPC
Class: |
A61F 2/4405 20130101;
A61F 2310/00029 20130101; A61F 2002/30884 20130101; A61F 2002/30841
20130101; A61F 2002/4635 20130101 |
Class at
Publication: |
623/017.11 |
International
Class: |
A61F 2/44 20060101
A61F002/44 |
Claims
1. A metallic overlay constructed of cobalt-chrome or any other
biocompatible metal or metallic alloy presenting a smooth, polished
surface on its outside allowing for virtually frictionless joint
articulation and rough or porous construction on its inside that is
amenable to natural bone in growth to provide a permanent fixation.
Said inlay is generally shaped to fit the natural contour of the
facet joint and sized to fit any or all of the forty-eight facet
joints located vertebral segments Occuput-C1 through L5-S1.
2. The Device of claim 1 has a porous inner surface made of the
same material as the device.
3. The Device of claim 1 has a porous inner surface made of a
different material as the device.
4. The Device of claim 1 wherein said component contains one or
more fins on its inner portion to provide lateral fixation.
5. The Device of claim 1 wherein said component contains one or
more teeth that may be crimped into the cortical bone to prevent
migration of the Device.
6. The Device if claim 1 wherein said component is constructed of a
non-metallic, non-degradable biocompatible material presenting the
same durability as its metallic version.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM
LISTING COMPACT DISK APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] The present invention relates generally to minimally
invasive spine surgery and, more particularly, a unique pre-made,
pre-shaped metallic implant implanted using an arthroscopic type
portal or classic open surgical method to achieve a spinal facet
joint hemi-arthroplasty to resurface any or all of the forty-eight
superior facets of the inferior Occiput-C1 through L5-S1 vertebrae
The use of pre-shaped metallic overlay for facet joint resurfacing
of diseased, painful, deteriorated or overstressed joints offers
three distinct advantages over larger prosthetic implants, which
are presently used in facet arthroplasty procedures: (1) using a
thin metallic overlay allows for minimally invasive insertion that
is safer, less traumatic and requires far less recovery time
compared to a prosthetic; (2) the overlay does not require the use
of cements, pedicle screws or other fixation methods that can work
their way loose over time; and, (3) the implant has two fins to
provide lateral stability and two teeth to provide temporary
fixation and a rough or porous inner surface amenable to bone in
growth providing permanent natural fixation. The implant also has a
polished outside that allows for smooth, natural, pain free
articulation of the joint.
[0005] The implant and method are specifically designed for use in
an arthroscopic type portal for stand-alone procedures and may also
be used in classic open surgery. This implant provides a unique,
stronger and superior resurfacing and may be used for, but not
limited to: (1) an adjunct to instrumented vertebral fusion when
implanted in the two facet joints immediately above and below the
two joints adjoining the instrumentation thereby eliminating the
risk of collateral post-operative facet joint pain resulting from
additional stress placed on facet joints, (2) when used to
resurface adjoining facet joints directly above and below a disk
replacement by eliminating the risk of collateral post-operative
facet joint pain resulting from additional stress placed on facet
joints by the disk replacement, and, (3) as a stand-alone treatment
for diseased, painful or deteriorated facet joints.
BRIEF SUMMARY OF THE INVENTION
[0006] The invention accomplishes its goal of resurfacing a
painful, diseased or deteriorated spinal facet joints by providing
a method, resurfacing implant and instrumentation to replace the
joint surface with a small metal on bone overlay. The overlay,
constructed of cobalt chrome or such other biocompatible metal or
metallic alloy appropriate for joint hemi-arthroplasties, is one
size for adults and one size for children, similarly sized for
different facet joints or groups of joints in the spine and are
attached to the joint using a straightforward process without the
need for screws or cements and with the aid of custom designed
instruments. The facet joint may be accessed using an arthroscopic
type portal eliminating the need for open surgery, hospitalization
and long recovery periods. The procedure may also be performed as
an adjunct other procedures such as instrumented fusion and disc
replacement in a traditional open surgery. Because the side that
attaches to bone is porous, the bone heals onto it, permanently
fixing it into place. A uniquely designed set of blades and teeth
provides temporary fixation to the joint and prevents migration. A
unique crimping system allows the implant to be fixed into place,
holding it firmly until bone in growth is complete. The side making
contact with the joint is highly polished providing a smooth,
virtually frictionless surface that undergoes virtually no wear and
tear. The inside is rough or porous providing an amenable surface
for bone in growth.
[0007] According to one broad aspect of the invention, the system
comprises a surgical technique, uniquely designed instrumentation
and a unique metallic prosthetic overlay. The metallic overlay is
generally shaped to the natural contour of the bone it resurfaces
and is highly polished on the outside to provide frictionless
articulation of the joint and rough or porous on the inside to
promote and provide a surface to allow the natural bone to grow
into the overlay, providing a permanent fixation. In the interim
between implantation and bone in-growth, the overlay is
mechanically crimped into place using two teeth opposed to each
other and one to two blades on the inside of the implant that bite
into the bone to prevent lateral migration. The overlay is further
held into place by the natural pressure of the inferior and
superior sides of the joint as they come together in their natural
position.
[0008] The system includes any number of instruments allowing
preparation of the joint and the implant to be placed using a
minimally invasive surgical arthroscopic technique to access to the
joint that include a director probe to determine the correct facet
joint angle, a separator to assist with separation of the vertebrae
to improve access to the joint, an osteotome to make a small cut in
the bone to prepare the surface for the implant, a broach to
prepare the bone to match the implant shape, an impactor to impact
the implant into place and a crimp to fix the implant to prevent
migration prior to healing and a unique implant. By way of example
only, the director may include a planer blade or rasp to remove any
bone spurs or overgrowth and to flatten the facet joint surface in
preparation for implant placement.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING
[0009] Many advantages of the present invention will be apparent to
those skilled in the art with a reading of this specification in
conjunction with the attached drawings, wherein like reference
numerals are applied to like elements and wherein:
[0010] FIG. 1 represents an inside view of the implant showing the
teeth and blades used for temporary fixation.
[0011] FIG. 2 represents a properly completed procedure and the
resultant facet resurfacing using the device.
DETAILED DESCRIPTION OF THE INVENTION
[0012] In the United States alone, about 10% of the entire
population will suffer from back pain sometime in the next 12
months. More people will contract back pain in the next year than
any other injury or disease except the common cold and flu. About
one third will not recover and have to live with persistent,
disabling symptoms. The number is cumulative year after year.
[0013] One of the root causes of back pain, particularly persistent
and disabling back pain, are facet joints, small joints located
behind adjacent vertebrae in the spine that allow for spinal
motion.
[0014] Present surgical solutions available for the millions of
people with facet joint dysfunctions are complex, invasive,
high-risk operations requiring pedicle screws for fixation and
significant reduction or elimination of natural joints and
replacement with prosthetic apparatus such as those described in
U.S. Pat. Nos. 6,610,091, 6,579,319, 6,565,605, 6,132,464,
6,113,637 and U.S. Patent Application 2003/0028250. In general, the
present art requires prolonged recovery times, from 6 to 24 months,
and offers uncertain outcomes. High risk equates to frequent
litigation, which forces non-surgical symptomatic treatment while
the disease or consequences of injury progressively worsen.
[0015] With the advent of new, safer and less invasive surgical
techniques and technology, the growth of spine surgery now outpaces
every other orthopedic surgery segment. Its growth is further
fueled by an enormous demand.
Facet Joint Hemi-Arthroplasty solves these problems in two
ways:
[0016] 1. It can be a minimally invasive, low risk, fast (about 20
minutes per joint in an outpatient setting compared to about three
hours in a hospital followed by a three day stay), and has a
recovery time measured in a few weeks (compared to 6 to 24 months);
and, [0017] 2. It promises a high success rate, does not preclude
other surgical options, and is non-limiting and permanent.
[0018] The present invention is directed at overcoming, or at least
improving upon, the disadvantages of the prior art by achieving the
following: [0019] Reversal of the risk/benefit ratio of present
procedures versus the invention; [0020] A stand-alone minimally
invasive procedure versus major open surgery; [0021] It can also be
employed as an adjunct to major open surgery in concert with long
fusion and with disc replacement surgery to strengthen adjacent
facet joints. [0022] Outpatient versus inpatient surgery (about 20
minutes per joint versus hours); [0023] Reduced morbidity; [0024]
Reduced blood loss; [0025] Reduced time under anesthesia; [0026]
Reduced risk; [0027] Recovery time dramatically reduced; [0028]
Minimal scarring that decreases the risk of failed back syndrome
and improves revision surgery outcome; [0029] Reduced risk of post
operative infection by significantly reducing operating room time
and soft tissue destruction; [0030] Prolonging the functional life
of long segment fusions and disc replacement. [0031] No preclusion
of other surgical or non-invasive treatment options; and, [0032]
Projected high success rate by utilizing accepted procedures
facilitated through a new arthroscopic technique and resurfacing
implant.
[0033] It is anticipated that the availability of this method,
instrumentation and implant will increase the number of surgeries
performed because they offer the first safe outpatient surgical
solution to a predominant cause of joint pain. The inventor also
expects that virtually all patients receiving this procedure will
be able to walk the same day as surgery and be fully functional
within a few weeks. Present surgical solutions require
hospitalization of about three days and six to twenty-four months'
recovery.
[0034] Aside from the obvious positive clinical outcome, the
significant favorable financial impact on disability, worker's
compensation and health care insurers is considerable.
[0035] Spinal facet implant units are calculated per joint. Each
patient has two joints per spinal segment and six segments (T12 to
L1 through L5-S1) in the lumbar spine, or twelve lumbar, fourteen
cervical and twenty-eight thoracic joints. Each surgery is likely
to involve multiple joints, with a probable average of 4 per
patient.
[0036] The invention accomplishes its goal of reducing, preventing
or eliminating spinal facet joint pain by providing a method,
resurfacing implant and instrumentation to replace the joint
surface with a small metal on bone overlay. The overlay,
constructed of cobalt chrome, a material previously approved by the
FDA for other joint hemi-arthroplasty, or such other metallic
construction as may be safely used, is one size for adults and one
size for children, may be similarly sized for different joints and
is attached to the joint using a straightforward process without
the need for screws or cements with the aid of custom designed
instruments. The joint may be accessed using an arthroscopic type
portal eliminating the need for open surgery, hospitalization and
long recovery periods (unless the procedure is performed as an
adjunct other procedures such as instrumented fusion and disc
replacement in a traditional open surgery). Because the side that
attaches to bone is porous, the bone heals onto it, permanently
fixing it into place. A uniquely designed set of blades and teeth
prepares the joint and a unique crimping system allows the implant
to be fixed into place, holding it firmly until bone in growth is
complete. The side making contact with the joint is highly polished
providing a smooth, virtually frictionless surface that undergoes
virtually no wear and tear. The resurfacing implant is a securely
fixed porous hemi-arthroplasty of the facet joints of the
spine.
[0037] According to one broad aspect of the invention, the system
comprises a surgical technique, uniquely designed instrumentation
and a unique metallic prosthetic overlay. The metallic overlay is
generally shaped to the natural contour of the bone it resurfaces
and is highly polished on the outside to provide frictionless
articulation of the joint and rough and porous on the inside to
promote and provide a surface to allow the natural bone to grow
into the overlay, providing a permanent fixation. In the interim
between implantation and bone in-growth, the overlay is
mechanically crimped into place using two teeth opposed to each
other that bite into the bone and to prevent migration. The overlay
is further held into place by the natural pressure of the inferior
and superior sides of the joint as they come together in their
natural position.
[0038] The system includes any number of instruments allowing
preparation of the joint and the implant to be placed using a
minimally invasive surgical arthroscopic technique to access to the
joint that include a director probe to determine the correct facet
joint angle, a separator to assist with separation of the vertebrae
to improve access to the joint, an osteotome to make a small cut in
the bone to prepare the surface for the implant, a broach to
prepare the bone to match the implant shape, an impactor to impact
the implant into place and a crimp to fix the implant to prevent
migration prior to healing and a unique implant. By way of example
only, the director may include a planer blade or rasp to remove any
bone spurs or overgrowth and to flatten the facet joint surface in
preparation for implant placement.
[0039] FIG. 1 illustrates the device, which is variably sized to
accommodate different spinal facet joints. Its outer surface (1) is
highly polished to create a virtually frictionless surface and
designed to face the superior facet. The device itself is implanted
into the inferior facet. The inner surface (2), facing the inferior
facet, is rough or porous providing an amenable surface for bone in
growth. The inner blades (3), which rest into the bone in
pre-prepared slots, prevent lateral movement. The teeth (4) are
crimped into the joint to provide additional fixation and to
prevent migration.
[0040] FIG. 2 illustrates the device in situ with the polished side
(5) facing the superior facet (1) and the rough or porous side (6)
facing the inferior facet (2). The polished side (5) creates a
direct metal to bone contact, effecting a durable resurfacing.
Crimped teeth (3) provide additional fixation and prevent migration
while blades (4) provide lateral fixation. The natural pressure
provided by the joint adds to the stability of the implant allowing
for unrestricted, natural motion (7).
* * * * *