U.S. patent number 3,719,186 [Application Number 05/136,345] was granted by the patent office on 1973-03-06 for surgical instrument for placement of bone pins and holes therefor.
This patent grant is currently assigned to University of Alabama in Birmingham. Invention is credited to James J. Merig, Jr..
United States Patent |
3,719,186 |
Merig, Jr. |
March 6, 1973 |
SURGICAL INSTRUMENT FOR PLACEMENT OF BONE PINS AND HOLES
THEREFOR
Abstract
A surgical instrument for placement of bone pins and holes
therefor having an outer cannula telescopically receiving an inner
cannula which in turn telescopically receives a stylus. The outer
cannula has symmetrically separable components and one end thereof
engages a bone in which a hole is drilled. A tool is detachably
connected to the outer cannula for retaining the outer cannula
assembly. An inner cannula terminates inwardly of said one end of
the outer cannula and a stylus extends to a point adjacent said one
end of the outer cannula.
Inventors: |
Merig, Jr.; James J.
(Birmingham, AL) |
Assignee: |
University of Alabama in
Birmingham (Birmingham, AL)
|
Family
ID: |
22472435 |
Appl.
No.: |
05/136,345 |
Filed: |
April 22, 1971 |
Current U.S.
Class: |
606/80; 606/916;
606/179 |
Current CPC
Class: |
A61B
17/1739 (20130101); A61B 2090/08021 (20160201); A61B
2017/1651 (20130101); A61B 2217/005 (20130101); Y10S
606/916 (20130101); A61B 2217/007 (20130101) |
Current International
Class: |
A61B
17/16 (20060101); A61B 17/17 (20060101); A61B
19/00 (20060101); A61b 017/16 (); A61b
017/18 () |
Field of
Search: |
;128/305,310,347,348,349R,35R,83,92EB |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
549,999 |
|
Dec 1942 |
|
GB |
|
1,213,369 |
|
Oct 1959 |
|
FR |
|
Primary Examiner: Pace; Channing L.
Claims
What I claim is:
1. A surgical instrument for use in the placement of bone pins and
drilled holes therefor;
a. an outer cannula having separable components with one end of
said outer cannula being adapted to be maintained in engagement
with a bone in which a hole is to be drilled,
b. a tool engagable with said separable components of said outer
cannula holding said components together in assembled position
while said tool is in one position relative to said components and
releasing said components upon movement of said tool to another
position,
c. an inner cannula telescoping into said outer cannula with one
end of said inner cannula terminating inwardly of said one end of
said outer cannula, and
d. a stylus telescoping into said inner cannula and extending to a
point adjacent said one end of said outer cannula restraining the
entrapment of soft tissue in said outer cannula.
2. A surgical instrument as defined in claim 1 in which said one
end of said outer cannula is serrated.
3. A surgical instrument as defined in claim 1 in which the end of
said stylus adjacent said one end of said outer cannula is
tapered.
4. A surgical instrument as defined in claim 1 in which the end of
said outer cannula opposite said one end is enlarged and said inner
cannula has an enlarged end portion fitting said one enlarged end
of said outer cannula.
5. A surgical instrument as defined in claim 4 in which said
enlarged end portions of said outer and inner cannulae are
concentric, cylindrical members which communicate with reduced
diameter, concentric, cylindrical portions, respectively, of said
cannulae.
6. A surgical instrument as defined in claim 5 in which said stylus
is provided with an outer surface which corresponds to and slidably
engages a portion of the inner surface of said inner cannula.
7. A surgical instrument as defined in claim 6 in which said
enlarged end portion of said inner cannula extends axially
outwardly of said outer cannula and the adjacent end of said stylus
extends axially outwardly of said inner cannula.
8. A surgical instrument as defined in claim 1 in which said outer
cannula is divided longitudinally into separate, matching sections
with outwardly opening locking grooves in said sections and said
tool is provided with contact surfaces along the edges of an
outwardly opening recess therein which engage said locking grooves
with a sliding fit to retain said sections in assembled
position.
9. A surgical instrument as defined in claim 8 in which each
locking groove is provided with an inner surface which flares
outwardly toward said one end of said outer cannula and said
contact surfaces on said tool correspond to and slidably engage the
adjacent inner surfaces of said locking groove.
10. A surgical instrument as defined in claim 8 in which said tool
is provided with an elongated handle which projects outwardly of
said outer cannula and supports said outer cannula while said outer
cannula is in assembled position.
Description
The invention described herein was made in part in the course of,
or under, a grant from the U.S. Public Health Service, Department
of Health, Education and Welfare.
BACKGROUND OF THE INVENTION
This invention relates to a surgical instrument and more
particularly to an instrument for the placement of bone pins and
holes therefor, such as where external pin fixation techniques are
employed.
Heretofore in the art to which my invention relates, difficulties
have been encountered in drilling holes into bones at precise
locations without damage to surrounding soft tissues. Also,
difficulties have been encountered in the insertion of the pin or
screw into the drilled hole without damage to the surrounding soft
tissue. Furthermore, visualization of pre-placed bur holes is
difficult, thus requiring tactile manipulation of the pin into the
bur hole. With prior art methods, the surrounding soft tissue is
often contaminated with debris due to the difficulty in drilling
the hole at the proper location and the difficulty in manipulating
the pin whereby it enters the drilled hole. This is especially true
in view of the fact that relatively large incisions are often
required in the external soft tissue in order to position the drill
bur and the bone pin.
BRIEF SUMMARY OF THE INVENTION
In accordance with my invention, I provide an instrument for the
placement of bone pins and holes therefor wherein an inner cannula
serves as a guide for the placement of the bur hole in the bone and
an outer cannula serves as a guide for the placement of the bone
pin within the hole. A stylus telescopes into the inner cannula to
prevent entrapment of soft tissue when directing the apparatus to a
bone. The outer cannula is divided longitudinally of its length to
provide symmetrically separable sections which are held in
assembled position by a tool which is detachably connected to the
outer cannula and also serves as a handle member for the outer
cannula and the components carried thereby whereby the bone pins
may be placed at selected inclinations.
A surgical instrument embodying features of my invention is
illustrated in the accompanying drawing, forming a part of this
application, in which:
FIG. 1 is a side elevational view, partly broken away and in
section, showing the instrument assembled;
FIG. 2 is a sectional view taken generally along the line 2--2 of
FIG. 1;
FIG. 3 is a view taken along line 3--3 of FIG. 1, drawn to a
smaller scale; and
FIG. 4 is a side elevational view showing the outer cannula with
the sections thereof in assembled position.
Referring now to the drawing for a better understanding of my
invention, I show an outer cannula 10 having, when assembled, a
cylindrical end portion 11 which is formed integrally with a
reduced diameter cylindrical portion 12. As shown in FIG. 4, the
outer cannula 10 is divided along a centrally disposed line 13 to
provide symmetrical and identical halves or sections at each side
of the line 13 which are separable from each other.
To retain the separate halves or sections of the outer cannula in
assembled relationship to each other, as shown in FIG. 1, I provide
an outwardly opening locking groove 14 in the lower portion of the
outer cannula 10 which corresponds to and slidably engagescontact
surfaces 16 which define the sides of an outwardly opening slot 17
in an elongated handle 18. Preferably, the handle 18 is relatively
flat whereby it requires a minimum of space to manipulate the tool.
Accordingly, the recesses 14 are of a dove-tail shape which receive
corresponding, inclined surfaces 16 defined along the sides of the
U-shaped slot 17 in the handle 18. The handle 18 thus serves as a
wrench to hold the outer cannula at selected inclinations and at
the same time retains the separate halves of the outer cannula in
assembled relation until the tool is separated from the outer
cannula.
As shown in FIGS. 1 and 4, the end of the outer cannula opposite
the enlarged diameter end 11 is serrated as at 19 to facilitate
stabilization of the apparatus on the cortical bone and prevent
movement of the apparatus while placing and drilling the bur hole
and during the installation of the bone pin. The enlarged diameter
portion of the outer cannula defines a cup-like receptacle 21 which
is adapted to receive a conventional type wrench for seating the
bone pin in a manner well understood in the art to which my
invention relates.
Telescoping into the outer cannula 10 is an inner cannula 22 having
an enlarged diameter portion 23 which slidably engages the inner
surface of the cup-like receptacle 21 of the outer cannula 10. The
enlarged diameter, cylindrical portion 23 of the inner cannula 22
is formed integrally with a reduced diameter cylindrical portion 24
which terminates inwardly of the end of the cylindrical member 12
carrying the serrations 19. Preferably, the cylindrical, reduced
diameter portion 24 of the inner cannula 22 terminates
approximately five millimeters inwardly of the end of the outer
cannula 10 carrying the serrations 19 to provide a space for
receiving water for coolant while the bur is in motion. This space
also allows the serrations 19 of the outer cannula 10 to engage the
cortical bone without difficulty and also prevents contact of the
cutting edge of the bur with the adjacent inner surface of the
inner cannula 22. The inner cannula 22 thus serves as a guide for
the bur drill for placement of the bur hole in the bone. The inner
surface of the enlarged diameter portion 23 of the inner cannula 22
defines a cup-like receptacle 26 which will accommodate
conventional bur-shafts and conventional hand pieces.
Telescoping into the reduced diameter, cylindrical portion 24 of
the inner cannula 22 is a central, solid stylus 27 which extends to
a position adjacent the serrations 19 on the outer cannula 10.
Preferably, the stylus extends to a position slightly outwardly of
the serrations 19 on the outer cannula to prevent the entrapment of
soft tissue in the outer cannula 10 when directing the apparatus to
a bone. As shown in FIG. 1, the portion of the stylus 27 within the
confines of the cup-like receptacle 26 is enlarged in diameter to
provide an annular shoulder 28 which limits movement of the stylus
inwardly of the inner cannula 22.
From the foregoing description, the operation of my improved
surgical instrument will be readily understood. A small incision is
made through the skin and subcutaneous tissue over the proposed
bone-pin site. The dimension of the incision should be
approximately the same as the outer diameter of the cylindrical
portion 12 of the outer cannula 10. A blunt dissection is performed
to periosteum. With the incision thus made, the apparatus is
directed to the bone with the stylus 27 in place and the outer
cannula held in assembled position by the tool 18. When bony
contact is established, the stylus 27 is removed and the serrations
19 of the outer cannula 10 are stabilized in the cortical bone. The
bore of the inner cannula 22 is filled with sterile water for
cooling purposes. The shaft of the bur drill is then inserted
through the inner cannula 22 and following bony contact of the
cutting portion of the bur drill, a hole is drilled in the bone
through one or both cortices. Since the lower end of the
cylindrical portion 24 of the inner cannula 22 is spaced from the
adjacent end of the outer cannula carrying the serrations 19,
sufficient room is provided for rotation of the cutting aspect of
the drill bur without engaging the inner surface of the cylindrical
portion 24.
After the hole is drilled, the inner cannula 22 is removed and
water is aspirated into and from the outer cannula to remove water
and any possible debris. Preferably, sterile water irrigations are
employed. The pin or screw, not shown, is then inserted into the
cylindrical portion 12 of the outer cannula 10 whereby the pin
automatically moves into the proper alignment with the opening
drilled in the bone. With the bone pin in engagement with the bur
hole, the pin is rotated by conventional means to completely or
partially secure the pin to the bone with the outer cannula still
in place. The large diameter cup-like receptacle 21 in the outer
cannula 10 permits insertion of a suitable tool into the outer
cannula for rotation of the bone pin or screw. After the bone pin
or screw has been anchored to the bone, the tool 18 is disengaged
from the grooved surface 14 of the outer cannula 10, thus
permitting separation of the outer cannula in two parts along the
separation line 13. With the two sections of the outer cannula 10
thus separated, the outer cannula is removed from the soft tissue
with the bone pin or screw remaining in place. The bone pin or
screw is then completely secured in the bone if it was only
partially secured prior to removal of the outer cannula.
From the foregoing, it will be seen that I have devised an improved
surgical instrument for use in the placement of bone pins and
drilled holes therefor. By providing means for guiding the shaft of
the bur drill and the bone pin into proper engagement with the bone
and preventing movement of the bur drill during the drilling
operation, there is no damage to surrounding soft tissues since the
bur drill and bone pin are manipulated within the confines of the
apparatus. Also, surrounding soft tissue is not contaminated with
debris due to the fact that debris is contained within the bore of
the outer cannula 10 and any possible debris within the outer
cannula is irrigated and aspirated prior to placement of the bone
pin. Also, the entire procedure for placement of the bone pin is
performed without the necessity of visualization of the pre-placed
bur hole for tactile manipulation of the pin in the bur hole.
Furthermore, my improved apparatus requires a minimal external soft
tissue incision to obtain bony contact and placement of the bone
pin and at the same time the apparatus is easily manuvered for
placement of the bone pins at various inclinations. Furthermore, my
improved instrument is simple of construction, economical of
manufacture, durable and may be subjected to conventional methods
of sterilization or may be disposable.
While I have shown my invention in but one form, it will be obvious
to those skilled in the art that it is not so limited, but is
susceptible of various other changes and modifications without
departing from the spirit thereof.
* * * * *