U.S. patent application number 12/009694 was filed with the patent office on 2008-05-22 for bone fixture apparatus and jig.
This patent application is currently assigned to Grampian Health Board. Invention is credited to Alan Johnstone.
Application Number | 20080119854 12/009694 |
Document ID | / |
Family ID | 9907884 |
Filed Date | 2008-05-22 |
United States Patent
Application |
20080119854 |
Kind Code |
A1 |
Johnstone; Alan |
May 22, 2008 |
Bone fixture apparatus and jig
Abstract
A bone fixture apparatus has an elongate fixture device intended
to be inserted in a metaphysical region of a long bone. The device
is inserted generally transversely of the direction of the
medullary cavity in the bone. The fixture device includes an
aperture extending laterally thereof and intended to accommodate an
intramedullary nail inserted longitudinally therethrough into the
cavity. The fixture device is further formed with an axial aperture
intended to receive a securing element capable of insertion therein
to firmly engage said nail with the fixture device. Also disclosed
is a jig arrangement for locating, relative to a long bone, the
bone fixture apparatus.
Inventors: |
Johnstone; Alan; (Aberdeen,
GB) |
Correspondence
Address: |
LERNER, DAVID, LITTENBERG,;KRUMHOLZ & MENTLIK
600 SOUTH AVENUE WEST
WESTFIELD
NJ
07090
US
|
Assignee: |
Grampian Health Board
Aberdeen
GB
|
Family ID: |
9907884 |
Appl. No.: |
12/009694 |
Filed: |
January 22, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10470507 |
Dec 30, 2003 |
7347861 |
|
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PCT/GB02/00423 |
Jan 31, 2002 |
|
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12009694 |
Jan 22, 2008 |
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Current U.S.
Class: |
606/64 ; 606/62;
606/87 |
Current CPC
Class: |
A61B 17/725 20130101;
A61B 17/7233 20130101; A61B 17/72 20130101; A61B 17/1725 20130101;
A61B 17/1717 20130101; A61B 17/744 20130101; A61B 2017/00902
20130101 |
Class at
Publication: |
606/064 ;
606/062; 606/087 |
International
Class: |
A61B 17/58 20060101
A61B017/58 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 31, 2001 |
GB |
0102488.4 |
Claims
1. A bone fixture apparatus for application to a metaphyseal region
of a long bone, the apparatus comprising an elongate fixture device
intended to be inserted, in said region, generally transversely of
the direction of the medullary cavity in said bone; wherein the
fixture device includes an intramedullary device-receiving aperture
extending laterally thereof and intended to accommodate an
intramedullary device inserted longitudinally therethrough into
said cavity, wherein said fixture device comprises first and second
components intended to be inserted coaxially into the bone from
opposite directions and adapted to interfit within the bone.
2. Apparatus according to claim 1 wherein the first and second
components are hollow and cylindrical.
3. Apparatus according to claim 2, wherein the first and second
components are of different diameter.
4. Apparatus according to claim 2, wherein the intramedullary
device-receiving aperture is provided in at least one of the first
and second components.
5. Apparatus according to claim 1, wherein the fixture device also
has an axial aperture, intended to receive a securing element
capable of insertion therein to firmly engage the said
intramedullary device with the fixture device.
6. Apparatus according to claim 5 wherein the axial aperture is
formed in at least one of the first and second components.
7. Apparatus according to claim 5 wherein said axial aperture is
screw-threaded and said securing element comprises a grub
screw.
8. A jig for inserting a bone fixture apparatus for a permanent
intramedullary device into a bone, the jig comprising: an elongate
insert comprising a temporary intramedullary portion and an
extension portion, which in use, is located outside of the
medullary cavity, in axial alignment with the temporary
intramedullary portion; and a hollow sleeve member having a bore to
enable the hollow sleeve member to be inserted over said extension
portion, the hollow sleeve member also bearing a guide portion
adapted to extend to at least one side of the bone in use, the
guide portion having at least one guide aperture that defines a
fixture apparatus insertion axis; wherein the extension portion has
a non-circular cross-section and wherein the bore of the hollow
sleeve member has a corresponding non-circular cross-section so
that, when the extension portion is located in the bore of the
hollow sleeve member, relative rotation of the extension portion
and the sleeve member is prevented.
9. A jig according to claim 8, wherein the guide aperture extends
transversely with respect to the axis of the elongate insert and is
intended to guide a drilling means for drilling in said bone a bore
to accommodate the bone fixture device.
10. A jig according to claim 9, also including sleevings of
differing dimensions for insertion in said at least one guide
aperture to accommodate drilling means of different diameters.
11. A jig according to claim 8, wherein the guide portion extends
to both sides of the bone in use, and is formed with a pair of
guide apertures extending transversely with respect to the axis of
the elongate insert, one guide aperture being provided on each side
of the bone; wherein the jig also includes a respective securing
sleeve for accommodation within each guide aperture; and whereby,
once the securing sleeves are inserted within the guide apertures,
the securing sleeves engage the bone thereby maintaining reduction
of the fracture.
12. A jig arrangement according to claim 8, further comprising a
cap member adapted to secure said sleeve member to said extension
portion.
13. A jig according to claim 8 wherein at least one of said
extension portion and said sleeve member is radiolucent.
14. A jig according to claim 8, wherein the extension portion has a
square cross-section and wherein the bore of the hollow sleeve
member also has a square cross-section.
15. A jig according to claim 8, wherein the temporary
intramedullary portion is a distinct component from the extension
portion, the temporary intramedullary portion being releasably
attachable to an end of the extension portion.
16. A jig according to claim 15, wherein the attachment end of the
extension portion has a shoulder that is adapted to engage with an
external bone surface when the extension portion is attached to the
temporary intramedullary portion and when the temporary
intramedullary portion is inserted into the medullary cavity of the
bone.
17. A jig according to claim 15, wherein the permanent
intramedullary device is releasably attachable to an end of the
extension portion.
18. A method of fixing a permanent intramedullary device to a long
bone, the method including the steps of: inserting an elongate
insert into the medullary cavity, the elongate insert including an
extension portion which remains outside of the medullary cavity;
inserting a hollow sleeve member over the extension portion, with
the extension portion being located in a bore of the hollow sleeve
member, wherein the extension portion and the bore of the hollow
sleeve member both have non-circular cross-sections such that
relative rotation is prevented; using the hollow sleeve member to
define a fixture apparatus insertion axis; withdrawing the elongate
insert from the intramedullary cavity; inserting a bone fixture
apparatus into the bone along the fixture apparatus insertion axis;
and inserting a permanent intramedullary device into the medullary
cavity and fixing the permanent intramedullary device to the bone
fixture apparatus, the permanent intramedullary device being
retained within an aperture of the bone fixture apparatus.
19. A method as claimed in claim 18, including the further step of
securing a cap on the hollow sleeve member, to limit relative axial
movement between the elongate insert and the hollow sleeve
member.
20. A method as claimed in claim 18, wherein the elongate insert
comprises a temporary intramedullary portion, which is releasably
attachable to the extension portion, and wherein the step of
inserting the permanent intramedullary device includes attaching
the permanent intramedullary device to the extension portion, and
using the extension portion to aid the insertion of the permanent
intramedullary device into the bone.
21. A method of fixing an intramedullary device to a long bone,
including the steps of: inserting a first component of a fixture
device in a direction lateral to the medullary cavity of the bone;
inserting a second component of a fixture device into the bone in
an opposite, lateral direction; inserting an intramedullary device
longitudinally into the medullary cavity of the bone and
interfitting the first and second components of the fixture device
together, to secure the intramedullary device to the fixture
device.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/470,507, filed on Dec. 30, 2003, the disclosure of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to bone fixture apparatus for use in
stabilizing fractures at or near the metaphyses of long bones, and
to jigs for use in connection therewith or separately.
[0003] Techniques based upon the use of intramedullary nails are
well established for stabilising fractures in long bones, and such
techniques are valuable in many respects, in particular because
they require minimal surgery adjacent the bone to be treated. Their
usefulness, however, is mainly restricted to the treatment of
fractures located intermediate the metaphyseal regions, and in
which there is little fracture damage running longitudinally of the
bone.
[0004] This invention aims, inter alia, to render intramedullary
nail technology suitable for use in the treatment of fractures at
or near metaphyseal regions of long bones.
SUMMARY OF THE INVENTION
[0005] According to the invention from one aspect, there is
provided a bone fixture apparatus for application to a metaphyseal
region of a long bone, the apparatus comprising an elongate fixture
device intended to be inserted, in the region, generally
transversely of the direction of the medullary cavity in said bone;
wherein the fixture device includes an aperture extending laterally
thereof and intended to accommodate an intramedullary nail inserted
longitudinally therethrough into said cavity, and wherein said
fixture device is further formed with an axial aperture intended to
receive a securing element capable of insertion therein to firmly
engage the said nail with the fixture means.
[0006] The fixture device may conveniently comprise a bolt-like,
screw-like or nail-like member intended for insertion into a
pre-drilled passage in the bone and to engage with cancellous bone
to provide a secure fixture which assists in stabilizing a fracture
and provides a rigid mount for the intramedullary nail.
[0007] In one preferred embodiment of the invention, the fixture
device comprises a bolt-like member including first and second
hollow, cylindrical components of different diameter inserted
coaxially into the bone from opposite directions and adapted to
interfit, within the bone, in any convenient manner so as to be
capable of asserting stabilising forces laterally of the long bone
under treatment.
[0008] In this embodiment, either or both of the hollow,
cylindrical components of the bolt-like member may be formed with
an nail-receiving aperture, extending transversely of the cylinder
axes and intended to accommodate an intramedullary nail inserted
therethrough into the medullary cavity of the bone. Moreover, one
or both of the cylindrical components is formed with an axially
extending aperture, preferably screw-threaded, into which a locking
device, such as a grub screw, may be inserted and tightened against
an intramedullary nail, disposed in said nail-receiving aperture,
to securely fix the nail to the bolt-like fixture means.
[0009] In another preferred embodiment, the fixture device
comprises a screw-like member, inserted from only one side of the
bone but otherwise with generally the same disposition, with
respect to the bone, as the bolt-like device described previously.
In this embodiment, it is essential for the screw-like component to
engage, with its screw-threaded distal end, into cancellous bone in
order to provide a firm fixture base. As with the previous
embodiment, the screw-like member is formed with a nail-receiving
aperture, extending transversely of its longitudinal axis, through
which an intramedullary nail can be inserted. The nail can be
firmly secured to the screw-like member, as before, by means of a
locking device, such as a grub screw, inserted into a suitable bore
running axially of the screw-like member.
[0010] In yet another preferred embodiment of the invention, the
fixture device comprises a finned nail-like member, the finned, and
sharpened distal end of which is intended to be embedded, by
conventional means, in cancellous bone. The remaining features of
the nail-like member are similar to those of the screw-like
member.
[0011] Another object of the invention is to provide jig
arrangements which, inter alia, are capable of accurately locating
incision and boring positions required as a precursor to the
insertion, into the bone, of the bone fixture apparatus of the
first aspect of the invention.
[0012] In accordance with this object of the invention there is
provided a jig arrangement for locating a bone fixture apparatus
relative to a long bone, the jig arrangement comprising an elongate
rod member with an intramedullary probe releasably attached to an
end thereof and in axial alignment therewith; the rod member being
provided, in the vicinity of its attachment to said probe, with a
shoulder intended to engage with an external bone surface when the
probe is inserted into the medullary cavity of the bone; said rod
member then acting as a core guide for a hollow sleeve member, also
forming part of said jig arrangement, intended to be inserted over
said rod member and bearing a guide portion at least partially
encircling said bone and formed with at least one aperture
extending transversely with respect to the axes of the rod member
and the probe and intended to guide a drilling means for drilling
in said bone a bore to accommodate a component of the bone fixture
apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order that the invention may be clearly understood and
readily carried into effect, certain embodiments thereof will now
be described, by way of example only, with reference to the
accompanying drawings, of which:--
[0014] FIG. 1 shows, in cross-section, a bone fixture apparatus in
accordance with a first embodiment of the invention;
[0015] FIG. 2 shows, in cross-section, a bone fixture apparatus in
accordance with a second embodiment of the invention;
[0016] FIG. 3 shows, in cross-section, a bone fixture apparatus in
accordance with a third embodiment of the invention;
[0017] FIGS. 4(a) and 4(b) show respective side views, relatively
displaced by 90 degrees, of an intramedullary probe used in
conjunction with jig arrangements according to certain embodiments
of the second aspect of the invention;
[0018] FIGS. 5, 6 and 7 show respective views of a jig arrangement
for use with the first embodiment of a bone fixture apparatus, in
accordance with the invention, described with reference to FIG. 1;
and
[0019] FIGS. 8, 9 and 10 show respective views of a jig arrangement
for use with the second and third embodiments of a bone fixture
apparatus, in accordance with the invention, described with
reference to FIGS. 2 and 3.
DETAILED DESCRIPTION
[0020] Referring to FIG. 1, there is shown a bone fixture apparatus
in accordance with a first embodiment of the invention, as applied
to a metaphyseal region of a long bone 1. The apparatus of this
embodiment comprises an elongate fixture device, indicated at 2,
intended to be inserted generally transversely of the direction of
the medullary cavity of the bone 1. The fixture device 2 includes
an aperture 3 extending laterally thereof and intended to
accommodate an intramedullary nail 4 inserted longitudinally
therethrough into the medullary cavity 5 of the bone 1, and the
fixture device 2 is further formed with an axial aperture 6
intended to receive a securing element 7 capable of insertion
therein to firmly engage the nail 4 with the fixture means 2.
[0021] The fixture device in this embodiment comprises a bolt-like,
member 8 intended for insertion into a pre-drilled-passage 9 in the
bone 1 and to engage with cancellous bone to provide a secure
fixture which assists in stabilising a fracture and provides a
rigid mount for the intramedullary nail 4.
[0022] In particular, in this first embodiment of the invention,
the bolt-like member 8, constituting the fixture device 2, includes
first and second hollow, cylindrical components 8a, 8b of different
diameter inserted coaxially into the bone 1 from opposite
directions and adapted to interfit, within the bone, so as to be
capable of asserting stabilising forces laterally of the long bone
under treatment. In this example, the components 8a and 8b interfit
by screw fitments, the larger diameter component 8a being formed
with a screw-threaded bore 10 which engages with an external screw
thread 11 formed on the outer surface of the smaller diameter
component 8b; the screw threading being provided at least in the
vicinity of the distal end of the component 8b.
[0023] As an alternative to the use of screw threading for the
interfitting between components 8a and 8b, any suitable alternative
arrangement can be used, such as bayonet fixtures or splined
fixtures, bearing in mind that it is desired that the fixture
device 2 shall provide sufficient force, directed laterally of the
bone 1, to stabilise a fracture in the vicinity of the metaphyseal
region thereof.
[0024] Either or both of the hollow, cylindrical components 8a, 8b
of the bolt-like member may contain the nail-receiving aperture 3,
extending transversely of the axes of the cylindrical components
and intended to accommodate an intramedullary nail 4 inserted
therethrough into the medullary cavity of the bone. In this
example, the larger diameter component 8a is formed with a lateral
throughbore 12 which constitutes the nail receiving aperture 3 in
its entirety.
[0025] Moreover, one or both of the cylindrical components 8a, 8b
is formed with a screw-threaded, axially extending aperture 13,
constituting the axial aperture 6, into which securing elements,
such as grub screws 7a, 7b, may be inserted and tightened against
the intramedullary nail 4, when disposed in the nail-receiving
aperture 12, to securely fix the nail 4 to the bolt-like fixture
means 8.
[0026] In some circumstances, depending upon factors such as the
nature of the fracture, the state of health of the bone itself and
the diameter of the components of the fixture means 8, it can be
advantageous to employ, between the bone 1 on the one hand, and the
heads 14 of one or both of the component parts 8a and 8b of the
fixture means 8 on the other hand, washer-type plates 15 to perform
a load-spreading function.
[0027] The heads 14 may be integrally formed with the respective
components 8a, 8b, or they may be separately formed and screwed
into the threaded bores 13 after the grub screws 7a, 7b have been
fitted therein. If this construction is adopted, however, the
proximal end of the bore 13 of one or both components 8a, 8b should
be suitably keyed so that the components can be relatively
manipulated to permit their interfitment as described above.
[0028] Referring now to FIG. 2, there is shown a second embodiment
of the invention, in which the fixture device 2 comprises a
screw-like member 16, for example a lag screw, inserted from only
one side of the bone but otherwise with generally the same
disposition, with respect to the bone, as the bolt-like device 8
described with reference to FIG. 1. In this embodiment, it is
essential for the screw-like component 16 to engage, with its
screw-threaded distal end 17, into cancellous bone 18 in order to
provide a firm fixture base. As with the embodiment of the
invention described with reference to FIG. 1, the screw-like member
16 is formed with a nail-receiving aperture 3, extending
transversely of its longitudinal axis, through which an
intramedullary nail 4 can be inserted. The nail 4 can be firmly
secured to the screw-like member 16, as described with reference to
FIG. 1, by means of a locking device, such as a grub screw 7,
inserted into a suitable bore 6 running axially of the screw-like
member 16.
[0029] It will be appreciated that the proximal end 19 of the
screw-like member 16 is suitably keyed to permit the member 16 to
be engaged, in any convenient, known manner, with the cancellous
bone 18, using conventional tools. As described previously, a
load-spreading washer-type plate 15 can be used against the bone
surface, being held in place by means of a cap member 20
screw-fitted into the bore 6.
[0030] Referring now to FIG. 3, a third embodiment of the invention
will be described, in which the fixture device 2 comprises a
finned, nail-like member 21, the finned, and sharpened distal end
22 of which is intended to be embedded, by conventional means, in
cancellous bone 18. The remaining features of the nail-like member
21 are similar to those of the screw-like member 16 described with
reference to FIG. 2, and will thus not be further described
herein.
[0031] In order to accurately locate the fixture device 2 of any of
the foregoing embodiments of the invention in relation to the bone
to which they are to be affixed, it is preferable to utilise a jig
arrangement of the kind to be described with reference to the
following FIGS. 4 to 10.
[0032] A common element of the preferred jig arrangements now to be
described is the use of a preliminary intramedullary device 23,
which will hereinafter be referred to as a probe since it is
intended to enter, temporarily and for alignment purposes, into the
intramedullary cavity. The probe 23 is withdrawn from the cavity
once the necessary alignment procedures have been completed and the
holes necessary to accommodate the fixture device have been
drilled, and is later to be replaced by the intramedullary nail 4.
The probe 23 is shown (inter alia) in FIGS. 4a and 4b, which are
side views from orthogonal directions, and it will be seen that it
comprises an elongate rod, slotted from its distal end 24 through
most of its length. At the proximal end 25 of the probe 23 is an
axially disposed bore hole 26 which is screw threaded, or otherwise
provided for interfitment with the remaining components of the jig
arrangement.
[0033] Referring now to FIGS. 5, 6 and 7, which show a jig
arrangement for use in connection with the embodiment of the
invention described with reference to FIG. 1, a first component of
the jig comprises an elongate rod member 27 with the probe 23
releasably attached to its distal end, in axial alignment with the
rod member 27, by means of a screw 28 protruding axially from the
end of the rod member 27 and engaging in the screw-threaded bore 26
formed in the proximal end of probe 23. The rod member 27 is
preferably of squared cross-section, and is provided, in the
vicinity of its attachment to the probe 23, with a shoulder 27a
intended to engage with an external surface of the bone 1 when the
probe 23 is inserted into the medullary cavity 5 of the bone 1. The
rod member 27 acts as a core guide for a second component of the
jig arrangement, which comprises a hollow sleeve member 29 intended
to be inserted coaxially over the rod member 27.
[0034] The sleeve member 29 bears a guide portion 30 configured and
positioned so as to extend to either side of the bone 1 and formed
with a pair of apertures 31 and 32 extending transversely with
respect to the axes of the rod member 27 and the probe 23, and
intended to guide a drilling means (not shown) of conventional kind
used for drilling, in said bone, the bore-like passage 9 (see FIG.
1) to accommodate the bone fixture device 8 of the bone fixture
apparatus 2. In this example, the guide portion 30 is of yoke-like
form, containing a pair of limbs extending to either side of the
bone. In alternative constructions, the guide portion 30 may be of
arcuate form, and dimensioned to encircle or partially encircle the
subject bone area.
[0035] A third jig component, comprising a cap member 33, is used
to retain the jig components 27 and 29 in stable and fixed
inter-relationship during the jigging operation. The cap member 33
may be screw-fitted or otherwise securable to the proximal end of
rod member 27 so as to hold the sleeve member 29 in place.
[0036] At least the major components of the jig arrangement, such
as the rod member 27, the sleeve member 29, the probe 23 and
possibly also the cap member 33, are preferably radiolucent so that
radiographic techniques can be applied where necessary to permit
positioning and alignment of critical features and components to be
checked.
[0037] In operation, and assuming that a longitudinal metaphyseal
fracture exists, it is to be expected that most surgeons will
prefer to reduce and hold the major metaphyseal fracture fragments
by percutaneous means prior to gaining access to the medullary
canal of the long bone in conventional manner. At this stage, the
surgeon may prefer to use a guide wire prior to reaming the
intramedullary canal to accommodate the correct diameter of probe
(such as 23) or alternatively ream the canal by hand. This done, a
probe 23 of appropriate length and diameter is attached to the rod
member 27 of the jig arrangement and inserted into the medullary
canal until the shoulder 27a abuts the end of the bone. Once in
place, the sleeve member 29 is slotted over the rod member 27 and
the cap member 33 screwed or otherwise fixed into place, ensuring
that the three components 27, 29 and 33 are locked together as one,
providing optimal placement of metaphyseal and diaphyseal
implants.
[0038] Short incisions, down to bone, are made over the medial and
lateral metaphyseal cortices, and the overlying soft tissue parted
using a periosteal elevator. Securing sleeves 34 and 35
respectively are screwed into position within the bore-aligning
apertures 31 and 32 formed in the guide portion 30 of the sleeve
member 29 to lie on the outer aspect of the medial and lateral
cortices of the metaphyseal fragments and thereby maintain
reduction of the fracture. Once the jig components are all secured
in place, it is possible to accurately estimate the length of the
bolt components 8a and 8b (see FIG. 1) required to achieve fixation
due to the inclusion, on the outer aspect of the securing sleeves
34 and 35 respectively, of measuring gauges 36 and 37 which can be
read as to their displacement relative to the outer rims of the
apertures 31 and 32 respectively.
[0039] Guide drill sleeves 38, 39 permitting the surgeon to
accurately place a guide wire across the metaphys are inserted
respectively into the apertures 31 and 32 and, after checking the
position using an image intensifier, the probe 23 is removed and
the appropriate diameter of drill inserted taking into account the
sizes of the bolt components 8a and 8b and of the intramedullary
nail 4 to be used.
[0040] After drilling the bone to the correct diameters,
appropriately dimensioned hollow, cylindrical half-bolt components
8a and 8b are inserted, and the smaller (8b) screwed into the
larger (8a) taking care to maintain correct alignment, especially
of the latter. Washer-type plates 15 may be required in some
circumstances to improve the hold on the bone, thereby improving
compression of vertical fractures through the metaphys. After the
bolt components are in place, the intramedullary nail 4 is attached
to the rod-like jig member 27 in place of the probe 23, and
inserted until the shoulder 27a of member 27 again rests against
the bone. Once correctly aligned (as checked if necessary with an
image intensifier) the grub screws 7a, 7b are tightened until the
nail 4 is securely held in the nail-retaining aperture 3 of the
bolt-like fixture means 8.
[0041] FIGS. 8, 9 and 10 show a jig arrangement suitable for use
with the bone fixture apparatus described with reference to FIGS. 2
and 3. This arrangement also makes use of a probe 23 as described
with reference to FIG. 4.
[0042] The principles of operation and application to the bone of
the jig arrangement shown in FIGS. 8 to 10 are similar to those
explained above in relation to the arrangement of FIGS. 5 to 7, and
thus further detailed explanation will not be given except insofar
as it relates to differences in the subject construction and/or
procedure.
[0043] The sleeve member 29 performs the same function as its
counterpart in the arrangement described with reference to FIGS. 5
to 7, but its associated guide member 30' differs from the member
30 described previously in extending only to one side of the bone
and being formed with only one drill-guiding aperture 31'.
[0044] Once the jig assembly, including a probe 23 as before, has
been fixed in place, as described previously, and the positions
checked by means of an image intensifier, additional K-wires 40 to
43 are inserted so as to straddle the probe 23. The probe 23 can
then be removed, and the appropriate diameter drill inserted
through guide aperture 31'; the diameter being selected so as to
take into account the intended size of the metaphyseal implant and
of the intramedullary device itself.
[0045] Sleeves of varying diameters inserted into the guide
apertures 31, 32 (FIGS. 5 to 7) and 31' (FIGS. 8 to 10) can
usefully be employed to adapt the apertures to accurately
accommodate drills and other tools of differing diameters.
* * * * *