U.S. patent application number 13/745765 was filed with the patent office on 2013-05-23 for fixation device and multiple-axis joint for a fixation device.
This patent application is currently assigned to AMEI TECHNOLOGIES, INC.. The applicant listed for this patent is AMEI Technologies, Inc.. Invention is credited to Miguel Franco, Michael Thomas, Paul Vasta.
Application Number | 20130131675 13/745765 |
Document ID | / |
Family ID | 43992066 |
Filed Date | 2013-05-23 |
United States Patent
Application |
20130131675 |
Kind Code |
A1 |
Vasta; Paul ; et
al. |
May 23, 2013 |
FIXATION DEVICE AND MULTIPLE-AXIS JOINT FOR A FIXATION DEVICE
Abstract
A fixator system includes an active strut that that can be
gradually or acutely adjusted. Adjustments can be made in six
degrees of freedom. Embodiments of the active strut can provide for
two of the six degrees of freedom being about a first common point
of rotation, and another two of the six degrees of freedom being
about a second common point of rotation. Embodiments of the fixator
can include one or more active struts in combination with one or
more passive struts. The passive struts can be rigidly locked or
can be unlocked so as to be freely and acutely adjustable while
gradual or acute adjustments are made using the one or more active
struts.
Inventors: |
Vasta; Paul; (McKinney,
TX) ; Franco; Miguel; (Addison, TX) ; Thomas;
Michael; (Van Alstyne, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AMEI Technologies, Inc.; |
Wilmington |
DE |
US |
|
|
Assignee: |
AMEI TECHNOLOGIES, INC.
Wilmington
DE
|
Family ID: |
43992066 |
Appl. No.: |
13/745765 |
Filed: |
January 19, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12618498 |
Nov 13, 2009 |
8377060 |
|
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13745765 |
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Current U.S.
Class: |
606/55 |
Current CPC
Class: |
A61B 17/62 20130101;
A61B 17/60 20130101 |
Class at
Publication: |
606/55 |
International
Class: |
A61B 17/60 20060101
A61B017/60 |
Claims
1. A fixator system, comprising: a first fixator base element; a
second fixator base element; a first active strut connected between
the first fixator base element and the second fixator base element;
and a first passive strut connected between the first fixator base
element and the second fixator base element; wherein the first
passive strut is configured to be placed into a passive locked
state such that the first passive strut is non-adjustable and
resists relative positional changes between the first and second
fixator base elements, and placed into an unlocked state such that
the first passive strut freely allows relative positional changes
between the first and second fixator base elements; wherein the
first active strut is configured to be placed into an active locked
state such that the first active strut resists relative positional
changes between the first and second fixator base elements, and
placed into an unlocked state such that the first active strut
freely allows relative positional changes between the first and
second fixator base elements; wherein the first active strut is
configured to allow relative positional changes between the first
and second fixator base elements while maintaining rigidity while
the first active strut is in the active locked state; and wherein
the first active strut is configured to allow adjustment of an
overall length of the first active strut when the first active
strut is in the active locked state.
2. The fixator system of claim 1, further comprising a second
active strut connected between the first fixator base element and
the second fixator base element; wherein the second active strut is
configured to be placed into an active locked state such that the
second active strut resists relative positional changes between the
first and second fixator base elements, and placed into an unlocked
state such that the second active strut freely allows relative
positional changes between the first and second fixator base
elements; wherein the second active strut is configured to allow
relative positional changes between the first and second fixator
base elements while maintaining rigidity while the second active
strut is in the active locked state; and wherein the second active
strut is configured to allow adjustment of an overall length of the
second active strut when the second active strut is in the active
locked state.
3. The fixator system of claim 1, further comprising a second
passive strut connected between the first fixator base element and
the second fixator base element; wherein the second passive strut
is configured to be placed into a passive locked state such that
the second passive strut is non-adjustable and resists relative
positional changes between the first and second fixator base
elements, and placed into an unlocked state such that the second
passive strut freely allows relative positional changes between the
first and second fixator base elements.
4. The fixator system of claim 1, wherein the first active strut
includes a joint comprising a driven element attached to the first
fixator base element, a first drive system that rotates the driven
element about a first axis of rotation, and a second drive system
that rotates the driven element about a second axis of rotation,
wherein the first and second axes intersect at a common point of
rotation of the driven element.
5. The fixator system of claim 1, wherein the first active strut is
configured to be placed into a passive locked state such that the
first active strut is non-adjustable and resists relative
positional changes between the first and second fixator base
elements.
6. A strut for a fixator system, the strut comprising: a first
joint; a second joint; and a central portion connected between the
first and second joints, the central portion being adjustable in at
least two degrees of freedom; wherein the strut is configured to be
placed into an active locked state such that the strut resists
relative positional changes between the first and second joints,
and placed into an unlocked state such that the strut freely allows
relative positional changes between the first and second joints;
wherein the strut is configured to allow for relative positional
changes between the first joint and the second joint while
maintaining rigidity while the strut is in the active locked state;
and wherein the strut is configured to allow for adjustment of an
overall length of the strut when the strut is in the active locked
state.
7. The strut of claim 6, wherein the first joint further comprises:
a first drive system that rotates a first driven element of the
first joint about a first axis of the first joint; and a second
drive system that rotates the first driven element about a second
axis of the first joint; wherein the first and second axes
intersect about a first common point of rotation of the first
driven element.
8. The strut of claim 6, wherein the central portion is lengthwise
adjustable.
9. The strut of claim 6, wherein the strut is configured to be
placed into a passive locked state such that the strut is
non-adjustable and resists relative positional changes between the
first and second joints.
10. A fixator system, comprising: a first fixator base element; a
second fixator base element; a first active strut connected between
the first fixator base element and the second fixator base element;
and a first passive strut connected between the first fixator base
element and the second fixator base element; wherein the first
passive strut is configured to be placed into a passive locked
state such that the first passive strut is non-adjustable and
resists relative positional changes between the first and second
fixator base elements, and placed into an unlocked state such that
the first passive strut freely allows relative positional changes
between the first and second fixator base elements; wherein the
first active strut is configured to be placed into an active locked
state such that the first active strut resists relative positional
changes between the first and second fixator base elements, placed
into a passive locked state such that the first active strut is
non-adjustable and resists relative positional changes between the
first and second fixator base elements, and placed into an unlocked
state such that the first active strut freely allows relative
positional changes between the first and second fixator base
elements; and wherein the first active strut is configured to allow
relative positional changes between the first and second fixator
base elements while maintaining rigidity while the first active
strut is in the active locked state.
11. The fixator system of claim 10, further comprising a second
active strut connected between the first fixator base element and
the second fixator base element; wherein the second active strut is
configured to be placed into an active locked state such that the
second active strut resists relative positional changes between the
first and second fixator base elements, placed into a passive
locked state such that the second active strut is non-adjustable
and resists relative positional changes between the first and
second fixator base elements, and placed into an unlocked state
such that the second active strut freely allows relative positional
changes between the first and second fixator base elements; and
wherein the second active strut is configured to allow relative
positional changes between the first and second fixator base
elements while maintaining rigidity while the second active strut
is in the active locked state.
12. The fixator system of claim 10, further comprising a second
passive strut connected between the first fixator base element and
the second fixator base element; wherein the second passive strut
is configured to be placed into a passive locked state such that
the second passive strut is non-adjustable and resists relative
positional changes between the first and second fixator base
elements, and placed into an unlocked state such that the second
passive strut freely allows relative positional changes between the
first and second fixator base elements.
13. The fixator system of claim 10, wherein the first active strut
includes a joint comprising a driven element attached to the first
fixator base element, a first drive system that rotates the driven
element about a first axis of rotation, and a second drive system
that rotates the driven element about a second axis of rotation,
wherein the first and second axes intersect at a common point of
rotation of the driven element.
14. The fixator system of claim 10, wherein the first active strut
is configured to allow adjustment of an overall length of the first
active strut when the first active strut is in the active locked
state.
15. A strut for a fixator system, the strut comprising: a first
joint; a second joint; and a central portion connected between the
first and second joints, the central portion being adjustable in at
least two degrees of freedom; wherein the strut is configured to be
placed into an active locked state such that the strut resists
relative positional changes between the first and second joints,
placed into a passive locked state such that the strut is
non-adjustable and resists relative positional changes between the
first and second joints, and placed into an unlocked state such
that the strut freely allows relative positional changes between
the first and second joints; and wherein the strut is configured to
allow for relative positional changes between the first joint and
the second joint while maintaining rigidity while the strut is in
the active locked state.
16. The strut of claim 15, wherein the first joint further
comprises: a first drive system that rotates a first driven element
of the first joint about a first axis of the first joint; and a
second drive system that rotates the first driven element about a
second axis of the first joint; wherein the first and second axes
intersect about a first common point of rotation of the first
driven element.
17. The strut of claim 15, wherein the central portion is
lengthwise adjustable.
18. The strut of claim 15, wherein the strut is configured to allow
for adjustment of an overall length of the strut when the strut is
in the active locked state.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of U.S. application Ser.
No. 12/618,498, which was filed on Nov. 13, 2009 and is
incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates in general to medical device
technology, and more specifically to external fixation devices and
to drive systems that allow precise control for positioning and
locking such fixation devices.
BACKGROUND
[0003] Without limiting the scope of the present disclosure, its
background is described in connection with external fixation
devices. Generally, external fixation devices are commonly used on
both the upper and lower limbs for both adults and children in a
variety of surgical procedures including limb lengthening,
deformity correction and treatment of fractures, mal-unions,
non-unions and bone defects.
[0004] One common external fixation device is known as the Ilizarov
Apparatus. The Ilizarov external fixation procedure involves a
rigid framework consisting of several rings or arches that are
placed externally around the limb and attached to injured (e.g.,
due to fracture) or surgically separated (e.g., for limb
lengthening and deformity correction) bone segments using special
bone fasteners (wires and pins) inserted into the bone segment and
connected to the related section of the external rigid framework.
The opposite rings of the rigid framework are connected by either
threaded or telescopic connection rods or by assembled uni-planar
or multi-planar angular hinges, which allow the surgeon to adjust
the relative position of the rings to each other longitudinally or
angularly over a period of time. This allows new bone to gradually
form in the gap between bone segments created by this distraction
technique. Once the desired position of bone segments is achieved
over the course of time (e.g., 2-6 weeks), the external apparatus
is stabilized into a fixed position and left on the bone segments
until the fracture is healed or newly formed bone is completely or
substantially mineralized, which could take up to an additional 3-6
months, depending on the nature of pathology and degree of
deformity.
[0005] Another common external fixation device is a Taylor Spatial
Frame as described in U.S. Pat. Nos. 6,030,386, 5,891,143, and
5,776,132. The Taylor Spatial Frame is a hexapod type of device
based on a Stewart platform but shares many components and features
of the Ilizarov apparatus. The Taylor Spatial Frame consists of two
external fixator rings attached to bone segments by wires or half
pins and connected together by six struts that may be lengthened or
shortened as necessary. Adjustment of strut lengths allows
manipulation of the bone segments in 6 axes (e.g.,
lengthening/shortening, external/internal rotation,
anterior/posterior horizontal translation, medial/lateral
horizontal translation, anterior/posterior angular translation, and
medial/lateral angular translation) to correct linear, angular and
rotational deformities simultaneously.
[0006] The fixation device would usually be placed on the affected
patient by medical personnel in such a way as to align the affected
body part during the healing process, holding the affected body
part in the proper position for treatment. Since applications of
such devices can include a wide variety of deformities, body sites,
and surgical implementations, there is a need for fixation devices
that can initially be acutely adjusted in order to accommodate such
variabilities and subsequently maintain the affected body part in
one desirable position. Moreover, a typical treatment regimen
requires frequent adjustments to be performed by the patient and/or
during repeated visits to medical professionals so that the
fixation device could be periodically and gradually adjusted,
providing the desired orientation to the affected body part and
setting the proper amount of stretching and support for healing.
Accordingly, there is also a need for fixation devices that allow
for gradual adjustments after the fractured body part is
substantially maintained in one position.
[0007] Thus, there is a need for an improved fixation device that
will allow medical professionals to make effective, calibrated
adjustments to the positioning of the injured body part.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For a more complete understanding of the features and
advantages of the present disclosure, reference is now made to the
detailed description along with the accompanying figures and in
which:
[0009] FIG. 1 is a perspective view of an external fixator ring
system according to one embodiment of the present disclosure that
includes an active strut in combination with a plurality of passive
struts;
[0010] FIG. 2 is a perspective view of a fixator assembly according
to one embodiment of the present disclosure;
[0011] FIG. 3A is a perspective view of a first embodiment of a
multiple-axis joint according to the present disclosure;
[0012] FIG. 3B is a cross-sectional view of a portion of the first
embodiment of the multiple-axis joint taken along section lines
3B-3B shown in FIG. 3A;
[0013] FIG. 3C is a cross-sectional view of a portion of the first
embodiment of the multiple-axis joint taken along section lines
3C-3C shown in FIG. 3B;
[0014] FIG. 3D is a top view of a portion of the first embodiment
of the multiple-axis joint shown in FIG. 3B;
[0015] FIG. 4A is a perspective view of a second embodiment of a
multiple-axis joint according to the present disclosure;
[0016] FIG. 4B is a partially-sectioned view of a portion of the
joint shown in FIG. 4A;
[0017] FIG. 5A is a perspective view of a third embodiment of a
multiple-axis joint according to the present disclosure;
[0018] FIG. 5B is a view of an internal joint of the third
embodiment of the multiple-axis joint shown in FIG. 5A;
[0019] FIG. 5C is a partially-sectioned view of the internal joint
shown in FIG. 5B;
[0020] FIG. 6A is a perspective view of a fourth embodiment of a
multiple-axis joint according to the present disclosure;
[0021] FIG. 6B is a top view of a portion of the joint shown in
FIG. 6A;
[0022] FIG. 7 is a view of an internal joint of the fourth
embodiment of the multiple-axis joint shown in FIG. 6;
[0023] FIG. 8 is a perspective view of a fifth embodiment of a
multiple-axis joint according to the present disclosure;
[0024] FIG. 9 is a view of an internal joint of the fifth
embodiment of the multiple-axis joint shown in FIG. 8;
[0025] FIG. 10A is a perspective view of a sixth embodiment of a
multiple-axis joint according to the present disclosure;
[0026] FIG. 10B is a view of a gear assembly and acute adjustment
assembly of the sixth embodiment of the multiple-axis joint shown
in FIG. 10A;
[0027] FIG. 11 is a view of an alternative gear assembly and acute
adjustment assembly of the sixth embodiment of the multiple-axis
joint shown in FIGS. 10A and 10B;
[0028] FIG. 12 is a perspective view of a first alternative
embodiment of an external fixator ring system according to the
present disclosure that includes a plurality of active struts;
[0029] FIG. 13 is a perspective view of a second alternative
embodiment of an external fixator ring system according to the
present disclosure that includes a plurality of active struts in
combination with a plurality of passive struts;
[0030] FIG. 14A is a perspective view of an embodiment of a passive
support strut that can be used with external fixator ring systems
of the present disclosure;
[0031] FIG. 14B is a perspective view of internal elements of the
passive support strut shown in FIG. 14A;
[0032] FIG. 14C is an partially-sectioned view of elements of the
passive support strut shown in FIG. 14B; and
[0033] FIG. 15 is a perspective view of another embodiment of a
passive support strut that can be used with external fixator ring
systems of the present disclosure.
DETAILED DESCRIPTION
[0034] While the making and using of various embodiments of the
multiple-axis joint according to the present disclosure are
discussed in detail below, it should be appreciated that the
present application provides many applicable inventive concepts
that can be embodied in a wide variety of specific contexts.
Without limiting the scope of the present disclosure, the
multiple-axis joint is described in connection with external
fixation devices. However, the multiple-axis joint can be used with
other devices. The specific embodiments discussed herein are merely
illustrative of specific ways to make and use the multiple-axis
joint disclosed herein and do not delimit the scope of the
application, and their usage does not delimit the application,
except as outlined in the claims.
[0035] FIG. 1 is a perspective view of an external fixator ring
system 100. The fixator ring system 100 includes a first fixator
ring 102a and a second fixator ring 102b, which serve as examples
of fixator base elements. The fixator rings 102a and 102b both
include a plurality of strut mounting positions 104. The fixator
rings 102a and 102b are connected by a plurality of connection
struts 106, 108, and 110, which are attached to the fixator rings
102a and 102b at the strut mounting positions 104.
[0036] Strut 106 is an active strut, whereas struts 108 and 110 are
passive struts. All of the struts 106, 108, and 110 are preferably
capable of being locked into a rigid state such that the rings 102a
and 102b are fixed relative to each other, and unlocked into a free
state such that acute adjustments can be made to the relative
positions of the rings 102a and 102b. Such acute adjustments are
desirable at certain times, for example during the initial
placement of the fixator ring system 100 onto an injured limb. The
passive struts 108 and 110 are limited to being either locked into
a passive locked state, which is a non-adjustable rigid state, or
being unlocked into a freely adjustable state. The active strut 106
is capable of being locked into an active locked state, which is a
rigid and adjustable state, or being unlocked into a freely
adjustable state. In some embodiments, the active strut 106 can
further be locked into a passive locked state so that it is even
locked from being adjustable. Thus, the active strut 106 differs
from the passive struts 108 and 110 in that the active strut 106 is
configured for an active locked state wherein the active strut 106
is capable of being controllably articulated for making fine or
gradual adjustments to the relative positions of the rings 102a and
102b with little or no loss in rigidity while such adjustments are
made. Such fine or gradual adjustments between the rings 102a and
102b are desirable after the initial placement of the fixator ring
system 100, for example as part of a treatment plan for an injured
limb that might require periodic gradual adjustments. Thus, the
fixator ring system 100 disclosed herein includes a combination of
active and passive struts 106, 108, and 110. While the fixator ring
system 100 includes one active strut 106 and two passive struts 108
and 110, alternative embodiments, including those described herein,
can include more than one active strut and more or fewer than two
passive struts.
[0037] The first fixator ring 102a includes a top surface 112 and
an opposing bottom surface (not shown). The top surface 112
includes numerous holes 116 that extend through the top surface 112
to the bottom surface (not shown). The holes 116 may be used for
attachment of wire and half-pin fixation elements (bolts), threaded
or telescopic connection rods, plates, posts or other device
connection elements to the first fixator ring 102a. In some
embodiments, the outer side surface 120 of the first fixator ring
102a can include numerous threaded apertures (not shown) that
provide additional attachment points for struts or other connection
elements (not shown). The second fixator ring 102b can be identical
or similar to the first fixator ring 102a.
[0038] Although the shape of the fixator rings 102a and 102b as
shown FIG. 1 is substantially circular, the shape of the fixator
rings 102a and 102b can vary to accommodate the physical contour of
various body parts to which the fixation system 100 would be
attached. For example, the fixator rings 102a and 102b can be
fixator base elements that are configured to have an oval shape,
D-shape, U-shape, C-shape, a polygon, or other irregular shapes. In
some exemplary embodiments, an elliptical fixator ring (not shown)
may be particularly advantageous. The insertion of pins or wires
into a patient's limb can cause the surrounding tissue to swell
unevenly, and in such a case, an elliptical fixator ring can
accommodate the uneven swelling better than a circular ring can.
The fixator rings 102a and 102b may be fixator base elements that
form a complete ring (full ring) or a segment or portion of a ring
(e.g., half ring, 1/3 ring, 1/4 ring, 3/8 ring, 5/8 ring, 2/3 ring,
3/4 ring, and other) that is either used alone or joined with other
segments or portions of the ring to form a fixator ring (not
shown). The fixator rings 102a and 102b may be fixator base
elements that are constructed of any material that provides the
structural rigidity necessary for fixation such as metal, alloy,
carbon fiber, plastic, ceramic and so forth. Moreover, the material
comprising the rings 102a and 102b may be radiotranslucent.
[0039] The strut 106 is an active strut that is adjustable in six
degrees of freedom. The strut 106 includes a first joint 122 and a
second joint 124 connected by a center portion 126. The first joint
122 includes a first driven element 128 that connects to one of the
strut mounting positions 104 of the first fixator ring 102a. The
second joint 124 includes a second driven element 130 that connects
to one of the strut mounting positions 104 of the second fixator
ring 102a. As discussed in greater detail below, the driven
elements 128 and 130 can each be articulated in two degrees of
freedom. For example, depending on the embodiment, the driven
element 128 can be angularly and/or rotationally repositioned
relative to the center portion 126 of the strut 106 and/or the
driven element 130 can be angularly and/or rotationally
repositioned relative to the center portion 126 of the strut 106.
The center portion 126 can also be lengthwise adjustable and/or
translationally and/or rotationally adjustable relative to one or
both of the first and second joints 122 and 124. Such embodiments
can allow for multiple degrees of freedom in repositioning the
first fixator ring 102a relative to the second fixator ring
102b.
[0040] FIG. 2 is a perspective view of a fixator assembly 200. The
fixator assembly 200 can be used as the strut 106 of the fixator
ring system 100, or can be used as a monolateral fixator. The
fixator assembly 200 includes the first joint 122 and the second
joint 124 as described above. The first and second joints 122 and
124 are connected by the center portion 126. The first joint 122
includes the driven element 128 that can be configured for
connection to another fixator base element, such as the fixator
ring 102a or 102b, or another type of fixator base element. As
discussed in greater detail below, the driven element 128 can be
angularly and/or rotationally repositioned relative to the center
portion 126 of the fixator assembly 200, as illustrated by arrows A
and B.
[0041] The fixator assembly 200 can include various other
adjustable elements in order to allow for six degrees of freedom.
For example, the fixator assembly 200 can include internal worm
gears at adjustment position 202 for allowing adjustments to be
made in directions indicated by arrows C and D; rack and pinion
gears at adjustment position 204 for allowing adjustments to be
made in directions indicated by arrow E; and rotational gearing at
adjustment position 206 for allowing adjustments to be made in
directions indicated by arrow F. The adjustable elements used to
provide for adjustments in directions indicated by arrows C, D, E,
and F can be selected from among a variety of know adjustment
systems.
[0042] As described in greater detail below, a technician can lock
the first joint 122 in a locked state where the driven element 128
is not free to move relative to other portions of the joint or
fixator assembly 200. The technician can unlock the first joint 122
or otherwise place the first joint into an unlocked state for acute
adjustments of the fixator assembly. In some embodiments, the first
joint 122 can also be placed into a gradual-adjustment state for
finer, more controlled movement and correction over time. The joint
122 can be manipulated either by hand or by a wrench on either one
or multiple faces of the joint housing. Combining the two joint 122
with a strut body such as the center portion 126 and the second
joint 124 can effectively allow for movement of two bone segments,
fixator base elements, or other elements through six degrees of
freedom.
[0043] The joint used as the first joint 122, and also as the
second joint 124 in some embodiments, can be selected from the
various embodiments of multiple-axis joints described in the
present disclosure. Embodiments of the joint 122 can include a
captured joint that can be driven in two degrees of freedom in
order to achieve angulations and/or rotations about a single point
in space. Embodiments can include a ball, which can be an at least
partially spherically-shaped element, which may be hollow or solid,
and which may have flat regions, projections, depressions, elements
that extend therefrom and/or regions that are threaded, slotted,
and/or otherwise provided with asperities. Embodiments of the joint
122 can include such a ball or nested ball/cylinder assembly that
is securely captured in a housing such that a driven element can be
oriented within a conical envelope protruding outward from the
center of rotation. The ball or ball/cylinder assembly can be
directly acted on by a driving mechanism (various exemplary forms
detailed herein) that can be either automated or manually operated
in order to achieve rotation and/or angulation of the ball itself.
This joint can be used as part of an external fixator in order to
move a fixator base element, bone segment, or other attachment
through these degrees of freedom accurately.
[0044] Thus, the fixator assembly 200 constitutes an example of a
single strut that can used in a monolateral configuration with
attachments connected to each end thereof that could connect to a
fixation element, such as a half-pin. First, fixation elements are
inserted and attached to bone segments. Second, the fixator
assembly 200 is unlocked and each end can include a driven element
128 that is attached to the appropriate fixation element and acute
adjustment would be made, if necessary. Third, the fixator assembly
200 would be locked to hold the bone segments in place. Next,
gradual adjustments could be made over time by unlocking the
assembly 200, adjusting the driven elements 128, and then once
again locking the assembly 200. This gradual adjustment over time
could move two bone segments relative to each other in all six
degrees of freedom.
[0045] FIGS. 3A through 3D show a first embodiment of a
multiple-axis joint, generally designated as multiple-axis joint
300. FIG. 3A shows a perspective view of the joint 300. The joint
300 includes a ball joint 302 captured within a housing 304. The
ball joint 302 includes a ball 306, which serves as an example of a
spherically-shaped element. FIG. 3B shows a cross-sectional view of
the ball 306 taken along section lines 3B-3B shown in FIG. 3A. FIG.
3C shows a cross-sectional view of the ball 306 taken along section
lines 3C-3C shown in FIG. 3B. FIG. 3D shows a top view of the ball
306, illustrating the axes of rotation.
[0046] The ball 306 includes two sets of gear teeth 308 and 310.
The gear teeth 308 and 310 are cut into the ball 306, for example
in a radial or circumferential configuration, and extend in
respective directions that are 90 degrees from one another. A first
gear 312 is mated with the first set of gear teeth 308. A second
gear 314 is mated with the second set of gear teeth 310. A driven
element 316 is rigidly attached to the ball 306 and extends out of
the housing 304 through a slot 318. Rotation of the first gear 312
will rotate the ball 306 within the housing 304. Rotation of the
second gear 314 will angulate the ball 306 within the housing
304.
[0047] Depending on the embodiment, the first and second gears 312
and 314 can be rotated, directly or indirectly, by the technician
in order to adjust the position of the driven element 316. In some
embodiments, the gears 312 and 314 can be connected, directly or
indirectly, to respective knobs, handles, or the like that can be
used by the technician for adjusting the position of the driven
element 316. In some embodiments, the gears 312 and 314 can be
configured to be drivable, directly or indirectly, by a removable
tool such as a hex key, screwdriver, or other tool that a
technician can use in order to adjust the position of the driven
element 316. For example, each of the gears 312 and 314 can include
a slot or the like, and the housing 300 can include an access hole
through which a tool can be inserted and mated with the gears 312
and 314 so that the technician can rotate the gears 312 and 314,
and thereby adjust the position of the driven element 316. In some
embodiments, each of the gears 312 and 314 can be attached to a
respective drive shaft that extends from the gear 312, 314 and can
be rotated either directly or using a removable tool such that
rotation of the drive shafts adjusts the position of the driven
element 316. Still further embodiments can include any desired
configuration for allowing a technician to perform an action that
causes rotation of selected gears 312 and 314 so that the
technician can adjust the position of the driven element 316.
[0048] The first gear 312 can be rotated for driving the ball 306
such that the driven element 316 is rotationally articulated about
a first axis of rotation 320 in directions indicated by arrows 322.
As the first gear 312 is rotated, the ball 306 rotates and the gear
teeth 310 slide within the gear teeth of the second gear 314,
thereby allowing rotation of the driven element 316 independently
of angulation of the driven element 316. The second gear 314 can be
rotated for rotating the ball 306 about a second axis of rotation
326 such that the driven element 316 is angularly articulated,
angulating the first axis of rotation 320, thereby moving the
driven element in directions indicated by arrows 324. As the second
gear 314 is rotated, the ball 306 rotates and the gear teeth 308
slide within the gear teeth of the first gear 312, thereby allowing
angulation of the driven element 316 independently of rotation of
the driven element 316. As shown in FIG. 3D, the first and second
axes 320 and 326 extend through the center of the ball 306. The
first axis of rotation 320 extends through the center of the ball
306 in a direction that is at least substantially perpendicular to
the second axis of rotation 326. The first and second axes of
rotation 320 and 326 intersect at a common rotation point about
which the driven element 316 can be driven in two directions or
degrees of freedom. The common rotation point is preferably at, or
substantially near, the center of the ball 306, thus allowing the
driven element 316 to be intuitively adjusted in two degrees of
freedom that intersect at a common point of rotation that is at or
substantially near the center of the ball 306. Note that the first
set of gear teeth 308 on top of ball 306 are not shown in FIG. 3D
so that the first and second axes of rotation 320 and 326 can be
more clearly shown.
[0049] In some embodiments, the gears 312 and 314 can be
repositioned relative to the ball 306 so as to be in contact with
the ball 306 in a first position as shown in FIG. 3A, and to be out
of contact with the ball 306 in a second position. For example, in
some embodiments, the gears 312 and 314 can be slid or otherwise
moved in and out of contact with the ball 306. When the gears 312
and 314 are in contact with the ball 306, the gears 312 and 314 act
as a break to prevent movement of the ball 306 unless one or both
of the gears 312 and 314 are rotating to drive the ball 306. Thus,
when the gears 312 and 314 are in contact with the ball 306, the
gears 312 and 314 act to effectively lock the joint 300. However,
once the gears 312 and 314 are moved out of contact with the ball
306 such that the first gear 312 is no longer mated with the first
set of gear teeth 308 and the second gear 314 is no longer mated
with the second set of gear teeth 310, the ball 306 can freely
move, thus allowing for acute adjustments of the position of the
driven element 316.
[0050] FIGS. 4A and 4B show a second embodiment of a multiple-axis
joint, generally designated as multiple-axis joint 400. FIG. 4A
shows a perspective view of the joint 400. The joint 400 can be
similar to joint 300, but includes a self-finding arm mechanism 402
in place of one of the gears and sets of gear teeth of joint 300.
In alternative embodiments, the self-finding arm mechanism 402 can
be in addition to the use the gears and sets of gear teeth of joint
300 discussed above.
[0051] The joint 400 can include a housing, such as housing 304;
however, the housing is not shown in FIG. 4 for purposes of
clarity. The joint 400 includes a ball joint 402. The ball joint
402 includes a ball 406, which serves as an example of a
spherically-shaped element. The ball 406 includes a set of gear
teeth 410. The gear teeth 410 are cut into the ball 406, for
example in a radial or circumferential configuration. A gear 414 is
mated with the set of gear teeth 410.
[0052] The joint 400 incorporates the usage of the gear 414 to
angulate the ball 406 and the arm mechanism 402 to rotate the ball
406. The arm mechanism 402 includes an arm 420 that acts within a
slot 422 in the top of the ball 406. FIG. 4B shows a
partially-sectioned view illustrating a view of the arm 420 within
the slot 422. Rotation of the arm 420 rotates the ball about the
first axis of rotation 320 as shown in FIG. 3D, whereas the gear
414 rotates the ball about the second axis of rotation 326 as shown
in FIG. 3D. The arm 420 includes a first arm section 420a and a
second arm section 420b connected by a joint 424. The joint 424 can
incorporate a universal joint, a ball and socket, or other
mechanism to allow for the arm 420 to rotate the ball 406 about the
first axis of rotation 320. A driven element 426 is rigidly
attached to the ball 406 and extends out of the housing (not
shown).
[0053] Thus, the ball 406 can include the same first and second
axes of rotation 320 and 326 as shown in FIG. 3D in connection with
ball 306. When the arm 420 is rotated, the gear teeth 410 in the
bottom of the ball 406 can slide within the gear 414, allowing
rotation of the ball 406 about the first axis of rotation 320
independently of angulation of the driven element 406. When the
gear 414 is rotated, the joint 424 in the arm mechanism 402 can
pivot as the ball 406 is rotated about the second axis of rotation
326, allowing angulation of the driven element 406 independently of
rotation of the driven element 406.
[0054] In some embodiments, the gear 414 and arm mechanism 402 can
be repositioned relative to the ball 406 so as to be in contact
with the ball 406 in a first position as shown in FIG. 4, and to be
out of contact with the ball 406 in a second position. For example,
in some embodiments, the gear 414 and arm mechanism 402 can be
moved in and out of contact with the ball 406. When the gear 414
and arm mechanism 402 are in contact with the ball 406, the gear
414 and arm mechanism 402 act as a break to prevent movement of the
ball 406 unless one or both of the gear 414 and arm mechanism 402
are driving rotation of the ball 306. Thus, when the gear 414 and
arm mechanism 402 are in contact with the ball 406, the gear 414
and arm mechanism 402 act to effectively lock the joint 400.
However, once the gear 414 and arm mechanism 402 are moved out of
contact with the ball 406 such that the arm mechanism 402 is no
longer mated with the slot 422 and the gear 414 is no longer mated
with the set of gear teeth 410, the ball 406 can freely move, thus
allowing for acute adjustments of the position of the driven
element 406.
[0055] FIGS. 5A through 5C show a third embodiment of a
multiple-axis joint, generally designated as multiple-axis joint
500. FIG. 5A shows a perspective view of the joint 500. The joint
500 can be similar to joint 300, but incorporates an internal joint
502 placed at the center of a ball joint 506 to perform rotation in
place of one of the gears and sets of gear teeth of joint 300. FIG.
5B shows a view of the internal joint 502, and FIG. 5C shows a
partially-sectioned view of the internal joint 502.
[0056] The joint 500 includes a housing 504, and a ball joint 506
captured within the housing 504. The ball joint 506 includes a ball
508, which serves as an example of a spherically-shaped element.
The ball 508 includes a set of gear teeth 510. The gear teeth 510
are cut into the ball 508, for example in a radial or
circumferential configuration. A gear 514 is mated with the set of
gear teeth 510. The joint 500 incorporates the use of the gear 514
to angulate the ball 508 and the internal joint 502 to rotate the
ball 508.
[0057] The internal joint 502 can be controlled by a control arm
520 that connects to a universal joint, a ball and socket joint, a
torque shaft/wire, or other mechanism suitable for rotating the
driven element 526. For example, as shown in FIGS. 5B and 5C, the
internal joint 502 can include an inner ball 530 and an outer ball
532, which serve as examples of spherically-shaped elements. Note
that the ball 508 is not shown in FIG. 5C so that the internal
joint 502 can be more clearly shown. The outer ball 532 is rigidly
connected to the control arm 520, and the inner ball 530 is rigidly
connected to the driven element 526. The outer ball 532 includes a
pin 534 that extends through the inner ball 530. The pin 534 acts
on the inner ball 532 such that the inner ball 532 rotates about
the longitudinal axis of the driven element 526, corresponding to
the first axis 320 shown in FIG. 3D, when the control arm 520 is
rotated. In some embodiments, the inner ball 532 can be fixed
relative to the ball 508 such that the ball 508 also rotates as the
control arm 520, inner ball 530, and driven element 526 are
rotated. In such embodiments, the driven element 526 can be
attached to the ball 508 instead of to the inner ball 530 as shown
in FIG. 5C, and the inner ball 530 can be fixed to the ball 508. In
other embodiments, the inner ball 530 and driven element 526 can be
free to rotate relative to the ball 508. In such embodiments, the
driven element 526 can be fixed to the inner ball 530 as shown in
FIG. 5C and pass through a hole through the ball 508.
[0058] The ball 506 can include the same first and second axes of
rotation 320 and 326 as shown in FIG. 3D in connection with ball
306. When the control arm 520 is rotated, the gear teeth 510 in the
bottom of the ball 506 can slide within the teeth of gear 514,
allowing rotation of the ball 508 about the first axis of rotation
320 independently of angulation of the driven element 526. When the
gear 514 is rotated, the gear 514 drives the ball 506 to rotate
about the second axis of rotation 326, allowing angulation of the
driven element 526 independently of rotation of the driven element
526. When the gear 514 is rotated, the internal joint 502 can pivot
about pin 534, allowing angulation independently of rotation.
[0059] FIGS. 6A, 6B, and 7 show a fourth embodiment of a
multiple-axis joint, generally designated as multiple-axis joint
600. FIG. 6A shows a perspective view of the joint 600. The joint
600 incorporates a ball joint 602 that includes an outer ball 604
and a driven element 606. Outer ball 604 serves as an example of a
spherically-shaped element. FIG. 6B shows a top view of the outer
ball 604, illustrating the axes of rotation 620 and 626 about which
joint 600 can drive the driven element 606. The driven element 606
extends in a more generally vertical direction compared to the
driven elements 316, 426, and 526 of the first through third
embodiment joints 300, 400, and 500, respectively, which extend in
a generally horizontal direction in a manner similar to the driven
element 128 used with fixators 100 and 200 shown in FIGS. 1 and 2,
respectively. This generally vertical orientation provides
increased strength in tension and compression as compared to the
more horizontal arrangement of the first through third embodiment
joints 300, 400, and 500.
[0060] In the fourth embodiment, rotation of the ball joint 602
causes angulations of the driven element 606 in two degrees of
freedom. Thus, unlike the first through third embodiments that
include a first axis of rotation 320 that is coaxial with the
driven element, the fourth embodiment joint 600 includes first and
second axes of rotation 620 and 626 that are perpendicular to each
other and to the longitudinal axis of the driven element 612. The
first and second axes of rotation 620 and 626 intersect at a common
rotation point about which the driven element 606 can be driven in
two directions or degrees of freedom. The common rotation point is
preferably at, or substantially near, the center of the outer ball
604, thus allowing the driven element 606 to be intuitively
adjusted in two degrees of freedom that intersect at a common point
of rotation that is preferably at or substantially near the center
of the outer ball 604.
[0061] The ball joint 602 is captured within a housing 608. FIG. 7
shows the ball joint 602 without the housing 608 and other elements
of the joint 600, and also shows portions of the ball joint 602
located within the outer ball 604. The ball joint 602 includes an
inner ball 610 disposed concentrically within, and free to move
relative to, the outer ball 604. The inner ball 610 serves as an
example of a spherically-shaped element. The outer ball 604 can be
driven to rotate in order to angulate the driven element 606 about
the first rotational axis 620, while the inner ball 610 can be
driven to rotate independently of the outer ball 604 for angulating
the driven element 606 about the second rotational axis 626.
[0062] A first drive arm 612 is attached to the inner ball 610 such
that the inner ball 610 rotates as the first drive arm 612 rotates
about the longitudinal axis of the first drive arm 612, which
corresponds to the second rotational axis 626. The driven element
606 is attached to the inner ball 610 and extends through the outer
ball 604 through a slot 604a in the outer ball 604. The slot 604a
defines a range of motion of the driven element 606 when driven by
the first drive arm 612. The first drive arm 612 is pivotally
attached to the inner ball 610, such that the first drive arm 612
is free to pivot relative to the inner ball 610 as indicated by
arrow 614. As shown in FIG. 6, the first drive arm 612 can be
driven by a first gear assembly 616. In alternative embodiments,
the first gear assembly 616 can be replaced by a belt drive, a
chain and sprocket drive, a torque shaft, a cable drive, or other
such mechanisms.
[0063] A second drive arm 620 is rigidly attached to the outer ball
604 such that the outer ball 604 rotates as the second drive arm
620 rotates about the longitudinal axis of the second drive arm
612, which corresponds to the first rotational axis 620. The outer
ball 604 can be driven by a second gear assembly 618. As shown in
FIG. 6, the second drive arm 620 can be driven by a second gear
assembly 616. In alternative embodiments, the second gear assembly
618 can be replaced by a belt drive, a chain and sprocket drive, a
torque shaft, a cable drive, or other such mechanisms.
[0064] FIGS. 8 and 9 show a fifth embodiment of a multiple-axis
joint, generally designated as multiple-axis joint 700. FIG. 8
shows a perspective view of the joint 700. The joint 700 includes a
cylinder 702 captured within a housing 704. FIG. 9 shows a
partially sectioned view of the cylinder 702, illustrating a ball
joint 706 disposed within the cylinder 702.
[0065] The ball joint 706 includes a ball 708, which serves as an
example of a spherically-shaped element, rigidly attached to a
driven element 710. The joint 700 incorporates the ball joint 706
such that the driven element 710 extends in a generally vertical
direction, similar to the fourth embodiment joint 600. The ball
joint 706 also includes a first drive arm 712. The first drive arm
712 is attached to the ball 708 such that the ball 708 rotates as
the first drive arm 712 rotates about the longitudinal axis of the
first drive arm 712. The first drive arm 712 is pivotally attached
to the ball 708, such that the first drive arm 712 is free to pivot
relative to the ball 708 as indicated by arrow 714. The driven
element 710 is attached to the ball 708 and extends through the
cylinder 702 through a slot 702a in the cylinder 702. The slot 702a
defines a range of motion of the driven element 710 when driven by
the first drive arm 712.
[0066] The rotational axis of joint 700 are like those of the
fourth embodiment joint 600 shown in FIG. 6B. Thus, the joint 700
includes first and second axes of rotation 620 and 626 that are
perpendicular to each other and to the longitudinal axis of the
driven element 710. The first and second axes of rotation 620 and
626 intersect at, or substantially near, the center of the cylinder
702, thus allowing the driven element 710 to be intuitively
adjusted in two degrees of freedom that intersect at or
substantially near the center of the cylinder 702. The ball 708 is
disposed within, and free to move relative to, the cylinder 702.
The cylinder 702 can be driven to rotate in order to angulate the
driven element 710 about the first axis of rotation 620, while the
ball 708 can be driven to rotate independently of the cylinder 702
for angulating the driven element 710 about the second axis of
rotation 626.
[0067] The first drive arm 712 is rigidly attached to the ball 708
and can be driven by a first gear assembly 716. The first gear
assembly 716 includes a first gear 718 that is rigidly attached to
the first drive arm 712 such that the first drive arm 712 rotates
with the first gear 718. The first gear assembly 716 also includes
a first rack member 720. The first rack member 720 is a
cylindrically cut rack having at least one threaded end 722. In
addition, or alternatively, the first rack member 720 can have a
second threaded end (not shown). The threaded end 722 mates with
similar threads within the housing 704 such that rotation of the
first rack member 720 about its longitudinal axis causes the first
rack member 720 to move translationally along its longitudinal
axis. The first rack member 720 can travel translationally and be
rotated at the same time, allowing gear teeth of the first gear 718
to slide along the cylindrical cuts of the first rack member 720 as
the first rack member 720 travels, thereby causing the first gear
718 to rotate. Rotation of the first gear 718 rotates the first
drive arm 712, which in turn rotates the ball 708, which results in
angulation of the driven element 710 about the second axis of
rotation 626. In alternative embodiments, the first gear assembly
716 can be replaced by a belt drive, a chain and sprocket drive, a
torque shaft, a cable drive, or other such mechanisms. When the
first rack member 720 is not being rotated, the threaded end 722
acts as a braking/holding mechanism with the threads providing the
braking force in the direction parallel to the longitudinal axis of
the first rack member 720. Thus, when the first rack member 720 is
not being rotated, the first rack member 720 acts to lock the first
gear 718 so that the first gear 718 cannot rotate, thereby
preventing the ball 708 from angulating the driven element 710. In
alternative embodiments, the rack member 720 can be cut at an angle
rather than cut cylindrically, for example the rack member 720 can
be a worm or include a worm portion, and in such embodiments the
gear 718 can be a worm gear.
[0068] A second drive arm 732 is rigidly attached to the cylinder
702 can be driven by a second gear assembly 736. The second gear
assembly 736 includes a second gear 738 that is rigidly attached to
the second drive arm 732 such that the second drive arm 732 rotates
with the second gear 738. The second gear assembly 736 also
includes a second rack member 740. The second rack member 740 is a
cylindrically cut rack having at least one threaded end 742. In
addition, or alternatively, the second rack member 740 can have a
second threaded end 744. The threaded end 742 and/or 744 mates with
similar threads within the housing 704 such that rotation of the
second rack member 740 about its longitudinal axis causes the
second rack member 740 to move translationally along its
longitudinal axis. The second rack member 740 can travel
translationally and be rotated at the same time, allowing gear
teeth of the second gear 738 to slide along the cylindrical cuts of
the second rack member 740 as the second rack member 740 travels,
thereby causing the second gear 738 to rotate. Rotation of the
second gear 738 rotates the second drive arm 732, which in turn
rotates the cylinder 702, which results in angulation of the driven
element 710 about the first axis of rotation 620. In alternative
embodiments, the second gear assembly 736 can be replaced by a belt
drive, a chain and sprocket drive, a torque shaft, a cable drive,
or other such mechanisms. When the second rack member 740 is not
being rotated, the threaded end 742 acts as a braking/holding
mechanism with the threads providing the braking force in the
direction parallel to the longitudinal axis of the second rack
member 740. Thus, when the second rack member 740 is not being
rotated, the second rack member 740 acts to lock the second gear
738 so that the second gear 738 cannot rotate, thereby preventing
the cylinder 702 from angulating the driven element 710. In
alternative embodiments, the rack member 740 can be cut at an angle
rather than cut cylindrically, for example the rack member 740 can
be a worm or include a worm portion, and in such embodiments the
gear 738 can be a worm gear.
[0069] FIGS. 10A and 10B show a sixth embodiment of a multiple-axis
joint, generally designated as multiple-axis joint 800. FIG. 10A
shows a perspective view of the joint 800. The joint 800 can be
substantially the same as joint 700, except for differences in the
gear assemblies discussed below. The joint 800 includes a housing
704 as shown in FIG. 8. The joint 800 also includes a cylinder 702
and a ball joint 706 as shown in FIG. 9 and described in connection
with joint 700. Elements of the joint 800 that can be the same or
substantially the same as corresponding elements of joint 700 have
retained the same element numbers, and the description of those
like-numbered elements in connection with joint 700 applies equally
to joint 800.
[0070] The joint 800 includes a first drive arm 712 rigidly
attached to the ball 708 and a second drive arm 732 rigidly
attached to the cylinder 702 as shown in FIGS. 8 and 9. A first
gear assembly 802 includes a first gear 718 that is rigidly
attached to the first drive arm 712. A second gear assembly 804 and
a second gear 738 is rigidly attached to the second drive arm 732.
The first and second gears 718 and 738 can angulate the driven
element 710 as described above in connection with joint 700 about
first and second rotational axes 620 and 626.
[0071] FIG. 10B shows an enlarged block diagram of the second gear
assembly 804, as well as a portion of first gear assembly 802. The
first and second gear assemblies 802 and 804 both allow for acute
and finer or more gradual adjustments. The first and second gear
assemblies 802 and 804 can be substantially the same; thus, the
following description of the second gear assembly 804 applies
equally to the first gear assembly 802.
[0072] The second gear assembly 804 includes a rack member 806
supported by a lead screw 808. The lead screw 808 can be rotated
for fine/gradual adjustment of the driven element 710. Rotation of
the lead screw 808 as indicated by arrow 810 causes the rack member
806 to translate along the lead screw 808 as indicated by arrow
812. The direction in which the rack member 806 travels relative to
the rotation direction of the lead screw 808 will depend on the
selected threading direction of the lead screw 808, which can vary
for different embodiments. As the rack member 806 travels
translationally along the lead screw 808, the rack member 806
engages with gear teeth of the second gear 738 causing the second
gear 738 to rotate as indicated by arrow 814.
[0073] The second gear assembly 804 also includes a first acute
adjustment block 816. The block 816 is part of an acute adjustment
assembly 818 that also includes an acute adjustment block 820 of
the first gear assembly 802. The acute adjustment assembly 818
includes a lock member 822. As shown in FIG. 10A, the adjustment
blocks 816 and 820 include teeth that can mate with teeth of the
lock member 822. As indicated in FIG. 10B, the lock member 822 can
be pulled away from the adjustment blocks 816 and 820 in order to
unlock the acute adjustment assembly 818. The lock member 822 can
be pushed against the adjustment blocks 816 and 820 (position shown
in FIG. 10A) in order to lock the acute adjustment assembly 818.
Thus, the lock member 822 can be pulled away from the adjustment
blocks 816 and 820 in order to unlock the acute adjustment assembly
818 and make acute adjustments to the driven element 710. While the
lock member 822 is pulled away from the adjustment blocks 816 and
820, the adjustment blocks 816 and 820 can travel translationally,
and independently of each other, in the directions indicated by
arrows 824 and 826. The lead screw 808 is fixed relative to the
adjustment block 816 such that the lead screw 808 translates with
the adjustment block 816. The threads of the lead screw 808 carry
the rack member 806 such that, if the lead screw is not rotating,
the rack member 806 translates in directions 812 with the lead
screw 808 and the adjustment block 816. As the rack member 806
travels translationally with the lead screw 808 and adjustment
block 816, the rack member 806 engages with gear teeth of the
second gear 738 causing the second gear 738 to rotate as indicated
by arrow 814. This allows for a more acute adjustment of the driven
element 710 about the first rotational axis 620 as compared to more
gradual adjustments that can be made as described above by rotating
the lead screw 810.
[0074] As mentioned above, the first gear assembly 802 can be
identical or substantially the same as the second gear assembly
804. Thus, the driven element 710 can be acutely and gradually
adjusted about the second rotational axis 626 via the first gear
718, first drive arm 712, and ball joint 706 using the first gear
assembly 802 and acute adjustment assembly 818 in the same manner
as describe above in connection with the second gear assembly
804.
[0075] The locking member 822 simultaneously engages and locks both
of the adjustment blocks 816 and 820 when pushed in (direction into
the page as indicated by direction 830 in FIG. 10B), and
simultaneously disengages and unlocks both of the adjustment blocks
816 and 820 when pulled out (direction into the page as indicated
by direction 832 in FIG. 10B). Thus, when the locking member 822 is
moved to the unlocking position, the driven element 710 can be
acutely adjusted along both the first and second rotational axes
620 and 626. In alternative embodiments, separate locking members
822 can be provided for each of the adjustment blocks 816 and 820.
Such an embodiment allows for acute adjustment of only one of the
rotational axes 620 and 626 at a time by unlocking only a selected
one of the two locking members 822, or simultaneous acute
adjustments by unlocking both of the locking members 822.
[0076] FIG. 11 shows an alternative second gear assembly 804a that
can be used with the joint 800. The first gear assembly 802 can be
similarly modified. The gear assembly 804a also allows for acute
and finer or more gradual adjustments.
[0077] The second gear assembly 804a includes the rack member 806
supported by an alternative lead screw 808a. The lead screw 808a
includes a helically threaded portion 850 that supports the rack
member 806. The lead screw 808a also includes a cylindrically cut
portion 852. The lead screw 808a can be rotated for fine/gradual
adjustment of the driven element 710. Rotation of the lead screw
808a as indicated by arrow 810 in FIG. 10B causes the rack member
806 to translate along the lead screw 808a as indicated by arrow
812 in FIG. 10B. The direction in which the rack member 806 travels
relative to the rotation direction of the lead screw 808a will
depend on the selected threading direction of the threaded portion
850 of the lead screw 808a, which can vary for different
embodiments. As the rack member 806 travels translationally along
the lead screw 808a, the rack member 806 engages with gear teeth of
the second gear 738 causing the second gear 738 to rotate as
indicated by arrow 814 in FIG. 10B.
[0078] The second gear assembly 804a also includes an alternative
acute adjustment assembly 818a that includes a lock member 854 and
the cylindrically cut portion 852 of the lead screw 808a. The lock
member 854 can be controlled to engage or disengage the cylindrical
cuts of the cylindrically cut portion 852 of the lead screw 808a.
The lock member 854 includes teeth that can mate with the
cylindrical cuts of the cylindrically cut portion 852 of the lead
screw 808a. The lock member 854 can be pulled away from the
cylindrically cut portion 852 of the lead screw 808a in order to
unlock the acute adjustment assembly 818a and thereby allow for
acute adjustments of the second gear assembly 804a. The lock member
854 can be moved to engage the cylindrically cut portion 852 of the
lead screw 808a (position shown in FIG. 11) in order to lock the
acute adjustment assembly 818a. Thus, the lock member 854 can be
pulled away from the cylindrically cut portion 852 of the lead
screw 808a in order to unlock the acute adjustment assembly 818a
and make acute adjustments to the driven element 710. While the
lock member 854 is pulled away from the cylindrically cut portion
852 of the lead screw 808a, the lead screw 808a can travel
translationally in the directions indicated by arrow 856. The
threaded portion 850 of the lead screw 808a carry the rack member
806 such that, if the lead screw 808a is not rotating, the rack
member 806 translates in directions 856 with the lead screw 808a.
As the rack member 806 travels translationally with the lead screw
808a, the rack member 806 engages with gear teeth of the second
gear 738 causing the second gear 738 to rotate as indicated by
arrow 814 in FIG. 10B. This allows for a more acute adjustment of
the driven element 710 about the first rotational axis 620 as
compared to more gradual adjustments that can be made as described
above by rotating the lead screw 810.
[0079] As mentioned above, an alternative first gear assembly 802
can be identical or substantially the same as the alternative
second gear assembly 804a. Thus, the driven element 710 can be
acutely and gradually adjusted about the second rotational axis 626
via the first gear 718, first drive arm 712, and ball joint 706
using the first gear assembly 802 and acute adjustment assembly
818a in the same manner as describe above in connection with the
second gear assembly 804a.
[0080] Still further embodiments of multiple-axis joints include
embodiments that combine various elements of the first through
sixth embodiment joints 300, 400, 500, 600, 700, and 800. For
example, the joints 300, 400, and 500 can be modified to include
one or more gear assemblies, such as gear assemblies 616, 618, 716,
736, 802, and 804, and/or acute adjustment assemblies, such as
acute adjustment assembly 818. More specifically, any of the gear
assemblies 616, 618, 716, 736, 802, and 804 can be used to drive
any of the gears 312, 314, 414, and 514. The gear assemblies 616,
618, 716, 736, 802, and 804 constitute examples of drive systems
that can be driven manually, by way of a handle, knob, removable
tool, key, or any other implement suitable for allowing a person to
make manual adjustments for driving the driven element (such as
driven element 316, 426, 526, 606, or 710) in a desired
direction.
[0081] Any of the multiple-axis joints 300, 400, 500, 600, 700, and
800 and variations thereof can be used as the first joint 122
and/or the second joint 124 of the fixator ring system 100 or the
fixator assembly 200. Still further embodiments of fixator ring
systems that can include any of the multiple-axis joints described
herein are described below in connection with FIGS. 12-14.
[0082] FIG. 12 shows a perspective view of a first alternative
embodiment of an external fixator ring system, generally designated
as external fixator ring system 900. The fixator ring system 900
includes a first fixator ring 902a and a second fixator ring 902b,
which serve as examples of fixator base elements. The fixator rings
902a and 902b both include a plurality of strut mounting positions
904. The fixator rings 902a and 902b are connected by a pair of
connection struts 906 and 908. In this embodiment, both of the
struts 906 and 908 are active struts. While two active struts 906
and 908 are shown, alternative embodiments can include more or
fewer active struts.
[0083] The first fixator ring 902a includes a top surface 912 and
an opposing bottom surface (not shown). The top surface 912
includes numerous holes 916 that extend through the top surface 912
to the bottom surface (not shown). The holes 916 may be used for
attachment of wire and half pin fixation elements (bolts), threaded
or telescopic connection rods, plates, posts or other device
connection elements to the first fixator ring 902a. The outer side
surface 920 of the first fixator ring 902a can include numerous
threaded apertures (not shown) that provide additional attachment
points for struts or other connection elements (not shown). The
second fixator ring 902b can be identical or similar to the first
fixator ring 902a.
[0084] Although the shape of the fixator rings 902a and 902b as
shown FIG. 12 is substantially circular, the shape of the fixator
rings 902a and 902b can vary to accommodate the physical contour of
various body parts to which the fixation system 900 would be
attached. For example, the fixator rings 902a and 902b can be
fixator base elements configured to have an oval shape, D-shape,
U-shape, C-shape, a polygon, or other irregular shapes. In some
exemplary embodiments, an elliptical fixator ring (not shown) may
be particularly advantageous. The insertion of pins or wires into a
patient's limb can cause the surrounding tissue to swell unevenly,
and in such a case, an elliptical fixator ring can accommodate the
uneven swelling better than a circular ring can. The fixator rings
902a and 902b may be fixator base elements that form a complete
ring (full ring) or a segment or portion of a ring (e.g., half
ring, 1/3 ring, 1/4 ring, 3/8 ring, 5/8 ring, 2/3 ring, 3/4 ring,
and other) that is either used alone or joined with other segments
or portions of the ring to form a fixator ring (not shown). The
fixator rings 902a and 902b may be fixator base elements
constructed of any material that provides the structural rigidity
necessary for fixation such as metal, alloy, carbon fiber, plastic,
ceramic and so forth.
[0085] The strut 906 includes a first joint 922 and a second joint
924 connected by a center portion 926. The first joint 922 and
second joint 924 are embodiments of multiple axis joints, such as
the fourth, fifth, or sixth embodiment joints 600, 700, and 800,
that include a generally vertical driven element. The first joint
922 includes a first driven element 928 that connects to one of the
strut mounting positions 904 of the first fixator ring 902a. As
discussed herein, the driven element 928 can be angularly and/or
rotationally repositioned relative to the center portion 926 of the
strut 906. The second joint 924 includes a second driven element
930 that connects to one of the strut mounting positions 904 of the
second fixator ring 902b. As discussed herein, the driven element
930 can be angularly and/or rotationally repositioned relative to
the center portion 926 of the strut 906. The connection strut 908
also includes first and second joints 922 and 924 and can be
identical to the first connection strut 906.
[0086] The joints 922 and 924 of the struts 906 and 908 can be
manipulated, for example by hand or using a tool such as a wrench,
to angulate and/or rotate (depending on the joint) the driven
elements 928 and 930. For example, the joints 922 and 924 can
include set screws or the like on the housings thereof for allowing
insertion of a wrench, screwdriver, or other such tool so that the
user can drive the gears/gear assemblies (such as gears 312, 314,
414, and 514 and/or gear assemblies 616, 618, 716, 736, 802, and
804) and thereby reposition the driven elements 928 and 930.
[0087] The center portion 926 can be a strut body such as center
portion 126 of the fixator assembly 200 shown in FIG. 2, which
includes various adjustable elements in order to allow for six
degrees of freedom. Combining two of the multiple-axis joints
described herein with such a strut body can allow for effectively
moving two bone segments, fixator base elements, or other elements
through all six degrees of freedom.
[0088] Two struts such as struts 906 and 908 can thus be used with
rings 902a and 902b in order to move two bone segments relative to
one another. First, the rings 902a would be attached to bone
segments with fixation elements such as half pins or k-wires.
Second, the struts 906 and 908 would be unlocked and attached to
the rings 902a and 902b with an angular separation preferably of
greater than 90 degrees and an acute adjustment would be made, if
necessary. Third, the struts 906 and 908 would be locked into an
active-locked state so as to hold the bone segments in place. Next,
gradual adjustment could be made over time by adjusting the driven
elements 928 and 930 of the struts 906 and 908 while the struts 906
and 908 are in active-locked states. This gradual adjustment over
time could move two bone segments relative to each other in all six
degrees of freedom.
[0089] FIG. 13 shows a perspective view of a second alternative
embodiment of an external fixator ring system, generally designated
as external fixator ring system 1100. The fixator ring system 1100
includes a first fixator ring 1102a and a second fixator ring
1102b, which serve as examples of fixator base elements. The
fixator rings 1102a and 1102b both include a plurality of strut
mounting positions 1104. The fixator rings 1102a and 1102b are
connected by a pair of active struts 906 and 908, which can be
identical to the active struts 906 and 908 described above, wherein
like elements of active struts 906 and 908 have retained like
element numbers. The fixator rings 1102a and 1102b are also
connected by a pair of passive struts 1130 and 1132, which can be
the same as, or similar to, passive struts 108 and 110.
[0090] The first fixator ring 1102a includes an outer side surface
1112a and an opposing inner side surface 1112b. Numerous holes 1116
that extend through the outer side surface 1112a to the inner side
surface 1112b. The holes 1116 may be used for attachment of
threaded or telescopic connection rods 1130 and 1132 between the
first and second fixator rings 1102a and 1102b. The holes 1116 may
also be used for attachment of wire and half pin fixation elements
(bolts), additional threaded or telescopic connection rods, plates,
posts or other device connection elements to the first fixator ring
1102a. The second fixator ring 1102b can be identical or similar to
the first fixator ring 1102a.
[0091] Although the shape of the fixator rings 1102a and 1102b as
shown FIG. 13 is substantially circular, the shape of the fixator
rings 1102a and 1102b can vary to accommodate the physical contour
of various body parts to which the fixation system 1100 would be
attached. For example, the fixator rings 1102a and 1102b can be
fixator base elements configured to have an oval shape, D-shape,
U-shape, C-shape, a polygon, or other irregular shapes. In some
exemplary embodiments, an elliptical fixator ring (not shown) may
be particularly advantageous. The insertion of pins or wires into a
patient's limb can cause the surrounding tissue to swell unevenly,
and in such a case, an elliptical fixator ring can accommodate the
uneven swelling better than a circular ring can. The fixator rings
1102a and 1102b may be fixator base elements that form a complete
ring (full ring) or a segment or portion of a ring (e.g., half
ring, 1/3 ring, 1/4 ring, 3/8 ring, 5/8 ring, 2/3 ring, 3/4 ring,
and other) that is either used alone or joined with other segments
or portions of the ring to form a fixator ring (not shown). The
fixator rings 1102a and 1102b may be fixator base elements
constructed of any material that provides the structural rigidity
necessary for fixation such as metal, alloy, carbon fiber, plastic,
ceramic and so forth.
[0092] The strut 906 includes a first joint 922 and a second joint
924 connected by a center portion 926. The first joint 922 and
second joint 924 are embodiments of multiple axis joints, such as
the fourth, fifth, or sixth embodiment joints 600, 700, and 800,
that include a generally vertical driven element. The first joint
922 includes a first driven element 928 that connects to one of the
holes 916 of the first fixator ring 902a. As discussed herein, the
driven element 928 can be angularly and/or rotationally
repositioned relative to the center portion 926 of the strut 906.
The second joint 924 includes a second driven element 930 that
connects to one of the holes 916 of the second fixator ring 902b.
As discussed herein, the driven element 930 can be angularly and/or
rotationally repositioned relative to the center portion 926 of the
strut 906. The connection strut 908 also includes first and second
joints 922 and 924 and can be identical to the first connection
strut 906.
[0093] The joints 922 and 924 of the struts 906 and 908 can be
manipulated, for example by hand or using a tool such as a wrench,
to angulate and/or rotate (depending on the joint) the driven
elements 928 and 930. For example, the joints 922 and 924 can
include set screws or the like on the housings thereof for allowing
insertion of a wrench, screwdriver, or other such tool so that the
user can drive the gears/gear assemblies (such as gears 312, 314,
414, and 514 and/or gear assemblies 616, 618, 716, 736, 802, and
804) and thereby reposition the driven elements 928 and 930.
[0094] The center portion 926 can be a strut body such as center
portion 126 of the fixator assembly 200 shown in FIG. 2, which
includes various adjustable elements in order to allow for six
degrees of freedom. Combining two of the multiple-axis joints
described herein with such a strut body can allow for effectively
moving two bone segments, fixator base elements, or other elements
through all six degrees of freedom.
[0095] The two struts 906 and 908 can thus be used with a set of
rings 1102a and 1102b in order to move two bone segments relative
to one another. First, the rings 1102a and 1102b would be attached
to the bone segments with fixation elements such as half pins or
k-wires. Second, the two struts 906 and 908 would be unlocked and
attached to the rings 1102a and 1102b with an angular separation
preferably greater than 90 degrees and an acute adjustment would be
made, if necessary. Third, the struts 906 and 908 would be locked
to hold the bone segments in place. Fourth, the passive struts 1130
and 1132 would be attached between the two rings 1102a and 1102b
for additional support against tissue and other forces. Next,
gradual adjustments could be made by unlocking the passive struts
1130 and 1132, adjusting the driven elements 928 and 930 of the
active struts 906 and 908, and then once again locking the passive
struts 1130 and 1132. This gradual adjustment over time could move
two bone segments relative to each other in all six degrees of
freedom. The passive struts 1130 and 1132 are removable such that
during x-rays or other scenarios when increased access or
visibility is necessary the passive struts 1130 and 1132 can be
removed, and the active struts 906 and 908 are sufficient for
rigidly maintaining the relative positions of the rings 1102a and
1102b.
[0096] FIGS. 14A through 14C show an embodiment of a passive
support strut 1200 that can be used as passive struts 108 and 110
in FIG. 1, and passive struts 1132 and/or 1130 in FIG. 13. The
passive support strut 1200 includes multiple joint members 1202
that are nested within one another, as shown in FIG. 14C, between a
pair of attachment studs 1208a and 1208b. The attachment studs
1208a and 1208b can be used to attach the passive support strut
1200 to fixator base elements or other devices. For example, the
attachment studs can be threaded studs that can pass through a hole
in a fixator ring and secured in place using a threaded nut.
Alternatively, the attachment studs can be configured pass through
a hole in a fixator ring and secured in place using a cotter pin.
Still further embodiments can use any desirable type of attachment
configuration.
[0097] The joint members 1202 can rotate in all three orthogonal
degrees of freedom relative to each other in order to change length
and direction and to follow fixator base elements as they are
driven in all six degrees of freedom by one or more active struts.
The passive support strut 1200 can be locked into a rigid state
such that the rings 102a and 102b are fixed relative to each other,
and unlocked into a free state such that acute adjustments can be
made to the relative positions of the rings 102a and 102b. As shown
in FIGS. 14B, the attachment studs 1208a and 1208b are each
connected to a central locking element 1206 by a connection element
1210 that passes through channels 1212 of the joint members 1202.
The connection element 1210 can be a cable, cord, string, wire, or
the like. The central locking element 1206 is disposed within a
central support member 1204. Rotation of the central locking
element 1206 can wind or unwind the connection element 1210,
thereby increasing or decreasing the compression on the joint
members 1202 between the central support member 1204 and the
attachment studs 1208a and 1208b. The locking element 1206 can be a
spool, cam, or other suitable device. The joint members 1202 can be
compressed together by operation of the locking element 1206 on the
connection element 1210 such that friction between the joint
elements 1202 prohibits relative movement between the joint
elements 1202. The passive stud 1200 can thus be locked. The
passive stud 1200 can be unlocked by operating the locking element
1206 in order to reduce the compression between the attachment
studs 1208a, 1208b and the central support member 1204. In some
embodiments, the central locking element 1206 can include slots,
grooves, detents, or the like for preventing the central locking
element 1206 from rotating due to the compressive forces of the
connection element 1210 while the passive support strut 1200 is
locked. In some embodiments, the central locking element 1206 can
include a handle, lever, or other such element for allowing a
technician to lock/unlock the passive support strut 1200. In some
embodiments, the central locking element 1210 can include a slot,
key, or otherwise be configured to be operated by a removable
tool.
[0098] FIG. 15 shows an alternative embodiment of a support strut
1300 that can be used in place of passive struts 108 and 110 in
FIG. 1, and passive struts 1132 and/or 1130 in FIG. 13. The support
strut 1300 includes first and second joints 1302a and 1302b
attached to opposing ends of a central portion 1304. In some
embodiments, the central portion 1304 can be lengthwise adjustable.
The first and second joints 1302a and 1302b can be attached to a
hole in a fixator ring and secured in place using a threaded screw,
bolt, combination of a nut and bolt, or any other desired
attachment means. The first and second joints 1302a and 1302b can
include any desired type of joint that allows for rotation in three
degrees of freedom, including heim joints, universal joints, ball
joints, or other joints.
[0099] All of the compositions and/or methods disclosed and claimed
herein can be made and executed without undue experimentation in
light of the present disclosure. While the compositions and methods
of this invention have been described in terms of preferred
embodiments, it will be apparent to those of skill in the art that
variations may be applied to the compositions and/or methods and in
the steps or in the sequence of steps of the method described
herein without departing from the concept, spirit and scope of the
invention. All such similar substitutes and modifications apparent
to those skilled in the art are deemed to be within the spirit,
scope and concept of the invention as defined by the appended
claims.
* * * * *