U.S. patent number 3,850,158 [Application Number 05/377,652] was granted by the patent office on 1974-11-26 for bone biopsy instrument and method.
Invention is credited to Elias George Elias, Youssef George Elias.
United States Patent |
3,850,158 |
Elias , et al. |
November 26, 1974 |
BONE BIOPSY INSTRUMENT AND METHOD
Abstract
A bone biopsy instrument comprising an obturator in the form of
a rod-like member having an enlarged head at one end and a wedge
shaped cutting and scraper blade at its opposite distal end
slidably fitted into a tubular sheath of lesser overall length
formed at its distal end to provide a conical tip converging toward
the distal end to define an annular cutting edge in alignment with
the passage defining wall and provided at its opposite proximal end
with an enlarged head in end butting contact with the head of the
obturator. The length of the tubular sheath is such that the bladed
distal end of the assembled obturator protrudes from the distal end
of the tubular sheath with the annular cutting edge of the tubular
sheath surrounding the base of the wedge shaped cutting and scraper
blade to provide an instrument the composite distal end of which
may enter through a minimal length skin incision to pierce the soft
subcutaneous tissue and dispose the bladed distal end of the
obturator in contact with the underlying bone segment to be
biopsied and permit the tubular sheath to be then advanced relative
to the obturator to contact the bone severing the surrounded soft
subcutaneous tissue and delimit a bone segment of finite diameter
to be removed as a sample for pathological and diagnostic study.
Upon removal of the obturator, the tubular sheath is rotated while
applying a light axial forward pressure to advance the annular
cutting edge into the bone to sever the delimited bone segment, a
helical thread being preferably formed on the conical tip of the
tubular sheath to feed the sheath cutting edge into the bone
structure.
Inventors: |
Elias; Elias George (Buffalo,
NY), Elias; Youssef George (Queens, NY) |
Family
ID: |
23490002 |
Appl.
No.: |
05/377,652 |
Filed: |
July 9, 1973 |
Current U.S.
Class: |
600/567;
606/134 |
Current CPC
Class: |
A61B
10/025 (20130101) |
Current International
Class: |
A61B
10/00 (20060101); A61b 010/00 () |
Field of
Search: |
;128/2B,2R,310 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Howell; Kyle L.
Attorney, Agent or Firm: Strauch, Nolan, Neale, Nies &
Kurz
Claims
What is claimed and desired to be secured by Letters Patent is:
1. A biopsy instrument for securing optimal samples of bone for
pathological and diagnostic studies comprising an elongated,
tubular sheath defining a cylindrical, axial through passage, said
tubular sheath at its proximal end having a head portion and at its
opposite distal end having an external conical wall portion
converging toward the distal end to define with the axial passage
wall an annular cutting edge; and a rod-like obturator slide fitted
into said sheath passage, said obturator at its proximal end having
a head portion engaging the opposed end face of said sheath head
portion and a distal end protruding beyond the distal end of said
sheath and comprising oppositely facing flats extending from said
annular cutting edge and converging toward the distal end of the
obturator to define a diametrically directed wedge shaped
blade.
2. The bone biopsy instrument of claim 1 wherein the conical wall
portion of said tubular sheath is provided with a helical screw
thread the lead end of which is coterminous with said annular
cutting edge and adapted to enter the bone outwardly of said
annular cutting edge when said sheath is advanced relative to said
obturator to initiate entry of said annular cutting edge into the
bone and thereafter, upon rotation of said sheath, to self thread
into the surrounding bone to advance the annular cutting edge into
the bone and sever an annular bone segment of the desired thickness
to be removed.
3. The method of securing an optimal sample of bone from human
beings and animals for use in pathological and diagnostic studies
using an instrument comprising a cylindrical rod-like obturator the
distal end of which is formed to provide a wedge shaped cutting
edge extending diametrically fitted into a cylindrical sheathing
the distal end of which is externally tapered to define an annular
cutting edge encircling the base circle of the wedge shaped
obturator distal end, comprising the steps of making a small skin
incision over the area to be biopsied; entering into the incision
the wedge shaped, cutting blade end of the obturator; advancing the
obturator and sheathing as a unit through said incision until the
tip of said wedge shaped cutting blade engages the bone thereby
cutting through and parting the subcutaneous soft tissue overlying
the bone area to be biopsied to permit entry of the sheathing
distal end; slidingly advancing the sheathing relative to said
obturator to advance the annular cutting edge through the parted
soft tissue subtended by the annular cutting edge thereby severing
the soft tissue within the annular cutting edge; rotating the
obturator to scrape the bone area within the annular cutting edge
and free the severed soft tissue from said bone area; retracting
the obturator from the sheathing; applying axial pressure to the
sheathing while rotating the sheathing to enter the annular cutting
edge into the bone to a desired depth thereby severing the bone
segment within the annular cutting edge from the surrounding bone
structure; applying a rocking movement to the sheathing to free the
severed bone segment from the underlying bone structure; and
retracting the sheathing through the incision with the dislodged
and severed bone segment therein.
4. The method of claim 3 wherein the tapered distal end of the
cylindrical sheathing is provided with a helical thread and the
axial pressure is applied momentarily to the sheathing to initiate
entry of the thread into the surrounding bone structure and
thereafter rotation of the sheathing is continued to effect
threaded self feeding of the annular cutting edge through the bone
to minimize splintering of the bone and bone sample as the annular
cutter completes its bone cutting action.
5. The steps of obtaining an optimal bone biopsy sample comprising
the steps of making a line incision of finite length through the
skin layer into the subcutaneous soft tissue; piercing the
subcutaneous soft tissue to a depth inward to the bone along the
full length of the incision while spreading the pierced tissue
defining the sides of the incision by a wedging action to form an
inverted truncated opening defining at the entrance of the incision
a circle the diameter of which equals the original incision length;
severing the subcutaneous soft tissue subjacently related to said
circle to the bone in a circular area to form a cylindrical opening
having a diameter equal to said circular area; removing the severed
soft tissue from the bone by a rotating scraping action; cutting
through the bone by a rotating cutting action to smoothly sever in
situ a bone disc biopsy sample of said finite diameter; breaking
the bone disc sample loose from the subjacent bone structure; and
retracting the intact bone disc sample from the incision.
Description
BACKGROUND OF THE INVENTION
The present invention relates to biopsy instruments and more
particularly to a method and apparatus for securing an optimal bone
sample or specimen from human beings or animals for pathological
examination and experimental purposes in making studies for
diagnostic purposes. At the present time, such samples or specimens
are only obtainable by use of needle type instruments which obtain
very tiny and unsatisfactory samples or by major surgical
procedures under general anesthesia which are time consuming,
subject the human patient or animal to considerable discomfort and
often objectionable trauma, and the obtaining of large samples,
much more than are actually needed. In the present invention, a
skin incision of minimal size is made over the area to be biopsied
and the instrument of the present invention dimensioned to enter
through the minimal size incision is employed to sever and remove
an adequate yet minimal sized sample or specimen. The instrument is
intended to be used under local anesthesia or during a surgical
procedure. Its use results in only slight discomfort of the human
patient or animal, objectionable trauma is avoided, and an optimal
sample or specimen is obtained.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a bone
biopsy instrument which is operative through a minimal length skin
incision over the bone area to be biopsied to remove an optimal
size bone sample or specimen or disk-like configuration for
pathological and diagnostic study.
A further object of the present invention resides in the provision
of a simple two part bone biopsy instrument made up of a rod-like
obturator and a tubular outer sheath adapted for unitary entry
through a small skin incision wherein the obturator distal end, in
the form of a diametrically directed, wedge-like, scraping tip,
protrudes axially beyond the distal end of the tubular sheath the
outer wall of which converges axially to form a conical tip
defining an annular cutting edge at the juncture of the base of the
wedge-like scraping tip and the main body of the obturator adapting
the tubular sheath, after contact of the bone by the obturator
scraping tip, to be moved axially relatively to the obturator into
contact with the bone to thereby cut through the soft tissue within
the annular cutting edge freeing the severed tissue to be scraped
free by rotation of the obturator, which is then removed by axial
retraction of the obturator, freeing the sheath to be advanced by
rotation into the bone to sever a disk-like bone sample or specimen
of predetermined optimal size.
Another object of the present invention resides in providing the
conical tip of the sheath of the biopsy instrument of the preceding
object with a helical thread extending from its tip to its base
whereby upon rotation of the sheath the thread will engage in the
bone structure surrounding the annular cutting edge to effect an
axial self feeding of the annular cutting edge into the bone
structure thereby diminishing the stresses on the bone sample
severed during rotation of the tubular sheath to provide a
disc-like sample or specimen of optimal size and thickness.
A further object of the present invention resides in the provision
of a method of securing an optimal bone sample or specimen from
human beings or animals for pathological and diagnostic studies
while minimizing the resulting discomfort and trauma normally
experienced in present day major surgical procedures employed to
obtain adequate size samples or specimens.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects will appear from the following description and
appended claims when read in conjunction with the accompanying
drawings wherein:
FIG. 1 is a side elevational view of an assembled bone biopsy
instrument constructed in accord with the present invention;
FIG. 2 is a top plan view of the assembled bone biopsy instrument
of FIG. 1;
FIG. 3 is a longitudinal sectional view of the tubular outer sheath
of the bone biopsy instrument illustrated in FIG. 1;
FIG. 4 is a side elevational view of the rod-like obturator and
scraping member of the bone biopsy instrument illustrated in FIG. 1
as viewed from the right side of FIG. 1; and
FIG. 5 is a fragmental sectional view on an enlarged scale
illustrating the relative positions of the distal ends of the
tubular sheath and obturator and scraping member of the bone biopsy
instrument of FIG. 1 after the instrument has been entered through
the skin incision and subcutaneous tissues to a position to effect
scraping of the surface of the bone sample or specimen to be
obtained and subsequent removal of the obturator and rotation of
the tubular sheath to sever the bone sample from the remainder of
the bone structure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With continued reference to the drawings where the same reference
numerals are employed throughout the several views to indicate the
same parts, numeral 10 designates generally the bone biopsy
instrument of the present invention. Referring for the moment to
FIGS. 1 and 2, instrument 10 is illustrated in its fully assembled
relation as held by the surgeon for inserting it through the skin
incision 11 (FIG. 5). As will be clear from the dot-dash
illustration of FIG. 1, instrument 10 is held by the surgeon with
his thumb 12 in end butted engagement with the enlarged head 13 at
one end of the obturator 14 (FIG. 4) and his index finger 15 and
middle finger 16 engaged beneath the plate-like head 17 at the
adjacently related end of tubular sheath 18 (FIG. 3). In this
assembled relation, the inner annular shoulder 19 of head 13 (FIG.
4) will be firmly engaged with the opposed upper surface 21 (FIG.
3) of head 17 defining the upper end of the through passage 22
(FIGS. 1 to 3) of tubular sheath 18. The opposite distal end 23 of
obturator 14, as will be clear from FIG. 1, will protrude beyond
the conical distal end 24 of tubular sheath 18. When held in this
manner, the two part biopsy instrument 10 is ready for use as will
be presently described.
In order to perform its intended function, the two parts of bone
biopsy instrument 10 should be constructed to reasonably close
tolerances to assure proper entry through a small skin incision 11
located over the bone area to be biopsied and the distal ends 23
and 24 should be constructed to accomplish their respective
obturating and scraping and cutting and self threading functions.
For purposes of illustration and guidance, the parts of a bone
biopsy instrument 10 for use on adult human beings should
preferably to constructed of stainless steel heat treated, polished
and pacivated to the following dimensions:
Tubular Sheath Overall Length 37/8 inches .+-. .010 Outer diameter
5/16 inch Wall thickness 5/64 inch Obturator and Scraping Member
Overall length 41/2 inches Outer diameter 5/32 inch
The distal end 24 of tubular sheath 18 is threaded externally as
indicated at 25 (FIGS. 1, 3 and 5) to provide a self cutting thread
adapted to thread into the bone structure surrounding the bone
sample or specimen to be obtained and formed to provide an annular
cutting edge 26 (FIG. 3) aligned with the inner wall of through
passage 22. While this may be accomplished in any suitable manner,
the following procedure is suggested to properly establish the
initial cutting edge of the thread. A brass slug is press fitted
into a tubular steel blank having the aforesaid dimensions to
provide an axial protrusion of three/sixteenths of an inch and
provided with a lathe tailstock centering aperture true to the
machined surfaces of the blank. The opposite end of the tubular
blank is apertured to receive in centering relation the lathe head
stock center. The blank with the slug insert in place is mounted in
a lathe fitted with a tool bit designed to cut a buttress thread
and the lathe set to cut 20 threads per inch along a 7.degree.
tapering path. The tool bit is advanced into the brass slug at a
point to begin the resulting 30.degree. angle of the buttress
thread at a distance of 0.158 to 0.160 inches from the free end of
the brass slug to assure that the root of the thread pass
uninterruptedly from the brass slug to the steel tube. Threading is
continued until the tool bit passes from the tubular sheath leaving
a conical threaded distal end 24 terminating at its smaller free
end in annular cutting edge 26. The opposite end of tubular sheath
18 is then completed by press fitting the generally rectangular
enlarged head 17 of heat treated, polished and pacivated stainless
steel thereon.
The obturator 14 is preferably formed by grinding distal end 23 to
form a wedge shape tip defined by oppositely facing flats 31 (FIG.
1) inclined relative to a diametrical plane at 30.degree. and press
fitting a knurled knob-like member of heat treated and pacivated
stainless steel on the opposite end to form enlarged head 13. To
insure a permanent connection between sheath 18 and its enlarged
head 17 and the rod-like obturator and its knob-like head 13, the
receiving passages of each are preferably chamfered at their outer
ends to provide an annular recess which is filled with a suitable
solder, preferably silver solder 32 to minimize corrosion. Such a
solder employed with the heat treated, polished and pacivated
stainless steel of sheath 18 and obturator 14 assures an instrument
which will withstand repeated sterilization and long useful
life.
In practice, the biopsy instrument of this invention is intended to
be used either under local anesthesia to obtain a bone sample or
specimen or during a surgical procedure to obtain such a sample or
specimen. In either case, the method of use consists in making a
minimal length skin incision over the bone area to be biopsied
sufficient only to permit the assembled tool, held as shown in FIG.
1, to be inserted into the incision with the protruding flats 31 of
the wedge shaped tip of the obturator extending lengthwise of the
incision. As a result of this initial insertion, the sharp tips
defined by flats 31 advances vertically through the soft
subcutaneous tissue underlying the sking incision while the flats
press the sidewall tissues and skin outwardly, particularly at and
near the skin surface, clearing a path for subsequent entry of the
cutting tip 26 of the surrounding sheath 18. Upon contact of the
very tip of obturator 14 with the bone segment to be removed, the
fingers 15 and 16 are removed from beneath enlarged head 17 and the
head 17 is grasped by the surgeon's other hand and sheath 18 is
advanced inwardly of the incision guided by the stationary
obturator 14 to pass cutting edge 26 through the minimal area of
subcutaneous tissue in its path into contact with the bone as
illustrated in FIG. 3. This initial inward movement of sheath 18
severs the minimal area of subcutaneous tissue lying within the
confines of the five-thirty seconds inch diameter circle defined by
cutting edge 26 from the surrounding tissue freeing the severed
subcutaneous tissue for removal from the bone sample to be
obtained. Removal of the severed subcutaneous tissue is effected by
lightly pressing cutting edge 26 against the bone and rotating
obturator 14 to scrape the bone area within cutting edge 26 of
sheath 18 to free the severed tissue. After the scraping action is
completed, obturator 14 is removed by retracting it through the
axial passage 22 of sheath 18 which is held lightly in contact with
the bone.
Upon removal of obturator 14, the surgeon grasps head 17 of sheath
18 and applies a slightly greater axial inward pressure to sheath
18 while bodily rotating sheath 18. This rotation under slightly
greater axial pressure causes cutting edge 26 and the leading
cutting point of helical thread 25 to enter the bone structure
initiating severance of the bone along a circular path defined by
cutting edge 26 and entry of thread 25 into the bone structure
radially outward of cutting edge 26. Upon continued rotation of
sheath 18 with only slight inward axial pressure, thread 25 will
self feed itself into the surrounding bone structure advancing
cutting edge 26 deeper into the bone with minimal contact of thread
25 with the surrounding tissue of the incision sidewalls distended
by its engagement with the base of conical tip 24. When sheath 18
has been advanced sufficiently into the bone, a determination
readily made by the skilled surgeon predicated on the number of
revolutions of head 17, the severed disclike bone sample or
specimen is freed from the underlying bone structure by a circular
or criss-cross motion of sheath 18. When thus freed, the disc-like
bone sample or specimen lodged within the distal end 24 of sheath
18 is removed intact by reverse rotation of sheath 18 to thread it
outwardly of the surrounding bone structure and then withdrawing
sheath 18 through the incision.
Cleansing of the wound made by the incision and removal of the bone
sample or specimen is then effected in well known manner and, if
necessary, suturing of the incision is effected to assure proper
healing of the wound.
The invention may be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
present embodiment is therefore to be considered in all respects as
illustrative and not restrictive, the scope of the invention being
indicated by the appended claims rather than by the foregoing
description, and all changes which come within the meaning and
range of equivalency of the claims are therefore intended to be
embraced therein.
* * * * *