U.S. patent number 3,807,394 [Application Number 05/277,569] was granted by the patent office on 1974-04-30 for fracture fixing device.
This patent grant is currently assigned to National Research Development Corporation. Invention is credited to Christopher George Attenborough.
United States Patent |
3,807,394 |
Attenborough |
April 30, 1974 |
FRACTURE FIXING DEVICE
Abstract
Orthopaedic fracture fixation is effected by use of a tube with
a spring extending through the tube bore and held under tension by
terminal means which secure the device relative to a bone. The
device can lie across the surface of a bone to bridge a fracture in
the manner of a staple by using terminal members in the form of
pins, screws or the like, and the spring tension can then serve to
assist reduction of the fracture. Alternatively, the device can
pass through the bone with terminal members held against opposite
parts of the bone surface. In this case, the device may be one of a
set used in threaded or other connection with an additional
intramedullary nail or bone plate. Various mechanisms can be used
for the terminal connections.
Inventors: |
Attenborough; Christopher
George (Winchelsea, EN) |
Assignee: |
National Research Development
Corporation (London, EN)
|
Family
ID: |
10406938 |
Appl.
No.: |
05/277,569 |
Filed: |
August 3, 1972 |
Foreign Application Priority Data
|
|
|
|
|
Aug 19, 1971 [GB] |
|
|
38989/71 |
|
Current U.S.
Class: |
606/60; 606/75;
606/71; 606/98 |
Current CPC
Class: |
A61B
17/7225 (20130101); A61B 17/68 (20130101); A61B
2017/0648 (20130101); A61B 17/0642 (20130101) |
Current International
Class: |
A61B
17/68 (20060101); A61B 17/72 (20060101); A61B
17/064 (20060101); A61f 005/04 () |
Field of
Search: |
;128/92B,92R,92BC,92A,92D,92C,92BA,92BB,83,84,87 ;32/4 ;85/49 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Yasko; J.
Attorney, Agent or Firm: Cushman, Darby & Cushman
Claims
I claim:
1. An orthopaedic fracture fixing device comprising a tube, an
elongate spring member located under tension along the bore of said
tube, and a pair of terminal means connected with respective ends
of said spring member, said terminal means extending externally of
the tube laterally relative to the longitudinal direction of said
tube across the ends of the tube for securing said spring member
relative to a bone and holding said spring member, under tension,
against relaxation into said tube.
2. A device according to claim 1 wherein said terminal means each
comprise a pin adapted for fixation in said bone by penetration
thereinto, which component is deployed laterally relative said
spring member, and said tube is slotted in a longitudinal sense
from at least one end thereof to slidably receive said
component.
3. A device according to claim 1 wherein said terminal means each
comprise a discrete first terminal member connected with the
respective end of said spring member, and a discrete second
terminal member, separably interconnected with said first terminal
member.
4. A device according to claim 3 wherein said first terminal member
is of apertured form, and said second terminal member is formed
with two apertures, and said terminal means each further comprise a
length of wire of which an intermediate portion passes through said
first terminal member, and the free end portions of said wire pass
respectively through said two apertures, to connect said terminal
members by twisting said wire free end portions.
5. A device according to claim 3 wherein each of said first and
second terminal members is of apertured form, the aperture of said
second terminal member receiving the apertured part of said first
terminal member therethrough, and each of said terminal means
further comprising a locking pin passing through said apertured
part.
6. A device according to claim 3 wherein said second terminal
member is of apertured form, and said first terminal member is
passed at least partly through said second terminal member and
thereafter rotated about said longitudinal direction to extend
across said second terminal member.
7. A device according to claim 3 wherein the external surface of
said tube is threaded at least part way along the length thereof;
an additional fracture fixing member internally threaded for screw
connection with said threaded external surface.
8. A fracture fixing assembly comprising a plurality of devices
according to claim 3 in each of which the respective tube is
externally threaded over an intermediate portion thereof, and an
elongate intramedullary member having a plurality of threaded
lateral bores therethrough individually receiving said devices in
screw connection.
9. A fracture fixing assembly comprising a plurality of devices
according to claim 3 and at least one elongate bone plate
constituting said second terminal in common for one set of
corresponding ends of said devices.
10. A fracture fixing assembly comprising a plurality of devices
according to claim 7 in each of which said threading extends over
an end portion of the respective tube, and an elongate bone plate
having a plurality of threaded lateral bores therethrough to
individually receive said devices in screw connection.
11. An orthopaedic fracture fixing device, comprising:
a rigid tube having a longitudinal bore;
a coil spring received in and extending along said bore;
a first terminal means extending laterally externally of the tube
adjacent one end of the tube;
first means connecting one end of the spring to said first terminal
means;
a second terminal means extending laterally externally of the tube
adjacent the other end of the tube;
second means connecting the other end of the spring to the second
terminal means, the length of the spring relative to the tube being
such that the second terminal means is pulled against the other end
of the tube by the spring and maintains the spring in tension;
interdigitable protrusion and recess means on said second terminal
means and said tube other end, arranged to not interdigitate until
the tube is rotated about its longitudinal axis to a predetermined
disposition relative to the second terminal means whereupon the
tension on said spring means pulls the protrusion and recess means
into interdigitation, thus moving the second terminal means toward
the first terminal means;
the length of the spring relative to the tube being such that the
spring remains tensioned when said protrusion and recess means are
interdigitated;
whereby the first and second terminal means may be connected to a
bone on opposite sides of a fracture thereof with the protrusion
and recess means not interdigitated, and the tube rotated relative
to the second terminal means to interdigitate the protrusion and
recess means, thus permitting the spring to shorten, drawing the
first and second terminal means together and thus reducing the
fracture.
Description
This invention concerns fracture fixing devices and more
particularly such devices for orthopaedic use in fixing bone
fractures.
More generally the invention provides a fracture fixing device
comprising a tube, an elongate spring member dimensioned to pass
longitudinally into the bore of said tube, and terminal means for
connection to the ends of said spring member to extend laterally
relative thereto and afford fixation for the device in connection
with a bone while holding said spring member under tension in said
tube.
Development of the invention in fact commenced with one form
thereof which is suited to use from outside a bone and which acts
in a generally similar manner to a staple in that it can bridge a
fracture in the bone and be secured to mutually fractured portions
of the bone. The added advantage of the invention is that the
spring is used in this application of the invention to apply force
acting to reduce the fracture.
More particularly in this first form of the invention, the terminal
means each comprise a pin, screw or equivalent component which is
deployed laterally relative to the spring member longitudinal axis
to act as the arms of a staple, and at least one end of the tube is
slotted to receive the pin. In practice, the device is assembled
with the pins held against the tube ends by the spring under
tension, but without either pin received in a slot. The device can
then be used to bridge a fracture, which may already be partly
reduced, by suitably fixing the pins. After this fixing, the tube
can be rotated to seat the relevant pin or pins in an associated
slot, whereat the spring tension acts to reduce the fracture, or
enhance an existing reduction.
It will be appreciated that there need be only one slot at one end
of the tube, but there can be slots at both ends and/or more than
one slot at either end. Also, it may be desirable to notch the
tube, at least at a slotted end, to form a seat for the respective
pin and reduce the possibility of undesirable rotation of the pin
into a slot during fixation or preliminary handling of the device.
Naturally such notching should not be such as to render rotation of
the tube relative to the pin too difficult when it is in fact
required.
Also, while terminal means involving simple pins will be useful for
many purposes, it may, as indicated above, be appropriate to
provide other forms of device. For example, bone screws passing
through an apertured spring terminal member which is itself
received in a tube slot rather than the screw may be preferable in
some circumstances.
The tube will normally be rigid, but this is not essential since it
will be appreciated that the tube need only have sufficient
longitudinal rigidity to maintain the terminal means at its ends
against the spring tension acting therebetween.
Further development of the invention has led to a second form
thereof which may be closely similar to the first form, but differs
in that it will be employed normally as an ancillary to secure or
enhance the stability of primary device such as an intramedullary
nail or a bone plate. In this case the device of the invention is
used from within the bone in the place of a bone plate screw, say,
where the bone is thin, porous or otherwise of too poor quality for
adequate conventional fixation, or in connection with an
intramedullary nail, say, where the medullary canal geometry is
subject to too great a variation to rely on the conventional
frictional stabilisation, as in the lower third of the femur.
In this form of the invention the terminal means can each comprise
an apertured first terminal member connected with one end of the
spring, and a second terminal member for disposition transverse to
the spring longitudinal axis and connection to the first terminal
member by a wire or other coupling member. In addition, the tube
may be externally threaded at least part way along its length, or
otherwise adapted in association with the primary device for
connection therewith.
For example, the tube may be externally threaded along a central
portion for screw connection with an intramedullary nail to extend
laterally therefrom through a bone. In this case the nail is
stabilized by connecting the first terminal members of the spring
second terminal members of plate or button-like form located on the
outer bone surface. Such connections can be made by wire passed
through the aperture of the first terminal member and also through
or round the second terminal member, and then twisted; by passing
the first terminal member through the second terminal member, and
then passing a locking pin through the aperture of the former
member; or in any other convenient manner.
It will be appreciated that this mode of securement is particularly
appropriate when the quality of the relevant bone is poor since the
forces to which the securement is subjected are spread across the
bone surface.
In another example, the device of the element may be connected
towards one end thereof with a bone plate, in which case the bone
plate can serve as part of the terminal means, i.e. the second
terminal member, for one end of the spring.
In any event, the above and other possible variations within the
more general scope of the invention will be better appreciated
following consideration of exemplary embodiments thereof as
illustrated in the accompanying drawings, in which:
FIG. 1 illustrates an embodiment of the invention in side
elevation,
FIG. 2 illustrates the embodiment of FIG. 1 in longitudinal
section,
FIG. 3 illustrates a modification of the embodiment of FIGS. 1 and
2,
FIG. 4 diagrammatically illustrates another embodiment of the
invention in association with an intramedullary nail, and
FIG. 5 similarly illustrates a modification of the embodiment of
FIG. 4 in association with a bone plate.
The embodiment of FIGS. 1 and 2 comprises a rigid circular
cylindrical tube 1, having at one end a pair of diametrically
opposed notches 2 and a longitudinal slot 3 located at a
circumferentially central position between the notches. A helical
spring 4 extends through the tube, but is shorter than the tube
when unstressed. Terminal means for the ends of the spring 4 are
provided by respective integral L-shaped components 5. In each
component 5, one arm 6 of the L-shaping is screw-threaded for
connection in the associated end of the spring, while the other arm
7 is tapered towards its free end to serve as a pin extending
radially across and beyond the relevant end of the tube.
The embodiment is shown ready for use, with the relevant pin seated
in one of the notches 2 and the other pin aligned therewith, and
the spring is of such length relative to the tube that the spring
must be extended under tension to achieve the illustrated
disposition of parts. After fixation in this disposition with the
pins secured in respectively different parts of a fractured bone
and the tube bridging the fracture, rotation of the tube causes the
notch-seated pin to pass into the slot 3 whereat the spring pulls
the pins closer together and so reduces the fracture. Naturally,
the spring tension is sufficiently high that, even when relaxed by
the closing movement of the pins, the reduced tension is still
useful.
In the modification illustrated by FIG. 3 for the above embodiment,
the terminal means 5 is replaced by a two-part terminal comprising
separate first and second members 8 and 10. The first member 8 is
in the form of an apertured plate 11 with a screw 12 extending from
its edge in the plane of the plate, while the second member 10 is a
bone screw dimensioned to pass through the aperture of the plate 11
with the screw head seating in or against the plate. The screw of
the first member connects with one end of the spring as in the
original embodiment, and the plate engages radially across the
relevant end of the tube, in the notch or slot, to hold the spring
under tension in similar manner to the previously proposed pin.
Securement to the bone is, of course, effected by the bone screw in
place of the pin.
The further embodiment of FIG. 4 is similar to that of FIG. 3 and
corresponding reference numerals are used where appropriate.
However, the terminal means for the spring differ in that the
second member is not a bone screw but a disc 12 having two
apertures 13 therein towards its center so that this member is, for
practical purposes, like a button. In fact the member in question
is used like a button in that the tube of the device is passed
laterally through a bored passage in a bone, and the spring is
tensioned between its ends by threading a wire w through the
aperture of the first terminal component, passing the free ends of
the wire through the respective apertures of the disc with the disc
located over the adjacent end of the bored passage, and then
tightening and twisting the wire to secure the resultant terminal
connection. This mode of fixation is useful, as noted above, when
the relevant bone is of poor quality for more conventional fixation
techniques and the wire securement can conveniently be effected by
use of the apparatus described in co-pending Great Britain Patent
Application No. 38988/71.
The device of FIG. 4, as so far described, can be used in its own
right for fixing an oblique fracture since it will serve to hold
the fractured parts together in a lateral sense under the spring
tension, while resisting movement in the longitudinal sense of the
bone by virtue of the rigidity of the tube around the spring. In
this last connection, it is to be noted that the tube will not
engage the second members of the terminal means, but there need be
no significant movement between these members and the main body of
the device if the main body terminates closely adjacent the bone
surface areas in which the bored passage emerges.
However, the situations in which the device of FIG. 4 may be used
alone are more likely to be those in which use is normally made of
an elongate fracture fixing member, such as an intramedullary nail
or a bone plate, to provide rigidity along the longitudinal
direction of the bone against lateral movement in a fracture.
Accordingly, the device of FIG. 4 is shown in association with an
intramedullary nail.
For this last purpose the nail, denoted at 14 is provided with a
plurality of lateral threaded bores 15 which are spaced apart in
uniform and parallel manner along the length of the nail, and each
bore 15 can be associated with the device so far described when
provided with a threaded portion 16 around the central part of its
tube. Briefly, to achieve this arrangement, the nail is located
along the relevant medullary canal, the bone is bored laterally to
form passages communicating with the canal in locations
corresponding to the bores of the nail, the tubes of the associated
devices are passed into the bores in the bone for screw connection
with the nail, and the devices are secured by way of their springs
and terminal means as described above. Naturally, not all of the
bores of the nail need be necessarily used in association with the
fixation devices, but a regular sequence of bores is provided in
the nail to allow selection to suit different circumstances.
For completeness in FIG. 4, an associated jig 17 is shown whereby
the lateral bores can be made in the bone to correspond with the
bores in the nail which are to be employed for fixation. This jig
comprises a primary elongate member 18 having a first end portion
20, formed with a sequence of lateral bores 21 corresponding to
those of the nail, and a second end portion 22 extending from the
first and formed with two spaced lateral bores 23 parallel to the
bores 21. The bores 21 are extended on opposite sides of the
portion 20 by tubular members 24, and at least one of the bores 21
nearer the free end of portion 20 communicates with an orthogonal
threaded bore 25 which receives a screw 26. The jig comprises a
secondary elongate member 27 similar to portion 22 of the primary
member in overall geometry and the provision of two lateral bores
28. The secondary member is connectable with the primary member in
parallel disposition by two tie rods 30 which pass at their
opposite ends through corresponding ones of the bores 23 and 28,
the tie rod ends being threaded for securement by nuts 31.
The secondary member 27 differs in the provision of a longitudinal
bore 32 therethrough and a pin 33 extending parallel thereto from
the end of the secondary member nearer to the first end portion 20
of the primary member. This bore and pin respectively co-operate
with correspondingly disposed stopped bores 34 and 35 in one end of
the nail, the bore 34 being threaded.
In use of this jig, an initial lateral bore is made in the bone to
communicate with the medullary canal, and the nail is passed into
the canal, with the end of the nail having the stopped bores 34 and
35 outermost relative to the entry point, until one of the
innermost lateral bores of the nail is aligned with the initial
bore in the bone. Then a rod 36 with a threaded end 37 is passed
into the bone bore to screw into the aligned bore of the nail,
while the other end of the rod 36 is passed into the corresponding
bore 21 of the primary member 18. Additionally, the secondary
member 27 is abutted against the outermost end of the nail with the
pin 33 located in the stopped bore 35, the longitudinal bore 32 of
the secondary member is aligned with the stopped bore 34 of the
nail, and a screw 38 is passed through the bore 32 to engage bore
34. Then the primary and secondary members are connected by the tie
rods 30, and the rod 36 secured by the screw 26, the tie rods
secured by the nuts 31, and the secondary member secured with the
nail by the screw 38, to provide a rigid ladder-like arrangement of
the jig and nail. The bores 21 of the jig primary member are then
fixed in alignment with the bores 15 of the nail, and the former
serve as guides for drilling lateral bores in the bone to
communicate with the nail and receive fixation devices.
In addition to providing enhanced securement in the presence of
poor bone, the fixation is enhanced, as noted earlier, for a nail
used in canal regions which do not normally offer adequate
frictional engagement. The more particular nail form and associated
fixation devices of FIG. 4 have been developed with the last
advantage in mind for use in the lower third of the femur, and the
nail is shaped for accommodation in this region with access from
the knee but without requiring the otherwise necessary, but not
necessarily successful, use of a nail of such length as to extend
along a major part of the femur. Also it will be appreciated that
the jig can be connected with the nail from either side.
The difficulty of fixation in poor bone is more likely to become
apparent in connection with bone plates, which are normally fixed
with screws, and FIG. 5 illustrates a modification of the fixation
device of FIG. 4 in association with such a plate. The principal
modification of the device is the provision of external threading
40 at one end of the tube of the device, rather than the center,
for screw connection with threaded bores 41 in a bone plate 42.
Also, while the terminal means for the fixation device spring can
be as shown in FIG. 4, differently modified means are shown at the
two ends of the device in FIG. 5 to further illustrate the
possibility of variation within the more general scope of the
invention.
At the end of the device for connection with the bone plate, the
terminal means comprise a first member 8 of apertured plate form as
in FIG. 3, while the bone plate serves as the second member. More
particularly, the aperture of the bone plate has a radial slot
extension 43 through which the first member plate can pass and be
locked by rotation in the manner of a turn-buckle.
At the other end, the device again employs a terminal device
comprising a first member 8 of apertured plate form, but instead of
association with a double-apertured button for connection by wire,
the second member comprises a disc 44 with a slot 45 through which
the member 8 can pass to be locked by a pin 46 threaded through its
aperture.
Clearly, both ends of the tube of the fixation device of FIG. 5 can
be threaded for association with respective bone plates on opposite
sides of the bone. Also, it will be apparent that screw connection
of the fixation device and plate is not essential, since the plate
can simply serve as an integrated second terminal means member for
a plurality of fixation devices.
While the invention has been more particularly described with
reference to a number of specific embodiments thereof, it has been
made very clear that it is susceptible to wide variation in its
superficially simple form. These variations will suit different
practical applications in orthopaedic fracture fixing, but exhibit
a common characteristic of providing tension by way of a spring
extending between fixation points, while the spring is stiffened
laterally by an encompassing tube.
* * * * *