Method of using flexible surgical instrument

A flexible surgical instrument is provided which is ideal for providing flexibility in surgery performed through a small incision, such as arthroscopic surgery. In one embodiment, the surgical instrument is provided with an outer member having at least one opening in a distal region and a hollow inner member disposed within the outer member for transmitting force applied to the proximal end to move a cutting implement disposed at the distal end. The cutting implement is constructed and adapted to perform a cutting function at the opening in the outer member. The hollow inner member is substantially flexible between its proximal and distal ends. The outer member is provided with a predetermined flexibility and rigidity such that the outer member is provided with sufficient flexibility to be manually bent by a surgeon during and operation, and provided with sufficient rigidity to retain such bend during the continued performance of the operation with the surgical instrument.

BACKGROUND OF THE INVENTION 
This invention relates to a surgical instrument, and in particular to 
flexible arthroscopic surgical instruments. 
Arthroscopic surgical instruments typically include a rigid outer tube 
within which a rigid inner tube is rotated by a motor. A cutting 
implement, such as a blade or abrading burr, is disposed on the distal end 
of the inner tube. Tissue or bone is exposed to the cutting implement 
through an opening in the distal end of the outer tube, and tissue or bone 
fragments cut by the rotating blade or burr are drawn through the interior 
of the inner tube along with irrigating fluid by the use of suction 
applied at the proximal end of the instrument. Examples of such surgical 
instruments are described in U.S. Pat. Nos. 4,203,444--Bonnell et al.; 
4,274,414--Johnson et al.; and 4,842,578--Johnson et al. 
In some instruments, the cutting implement is a hinged jaw mounted at its 
distal end, and is actuated by hand proximally with the intervening shaft 
being straight and rigid or rigid with a predetermined bend installed at 
the time of manufacturing. 
The aforesaid typical arthroscopic surgical instruments are linear, or in 
other words, straight between their proximal and distal ends. Such linear 
or straight instruments have limitations and disadvantages in many 
surgical operations, as most body parts and cavities of humans and animals 
are not straight, but have curved and/or irregular surfaces. It has been 
recognized that it is sometimes useful for such instruments to be curved 
to facilitate positioning the cutting implement against the tissue, bone 
or cartilage to be cut. Accordingly, more recently, arthroscopic surgical 
instruments have been developed which have a fixed bend or curve placed in 
the rigid outer tube at the time of fabrication of the instrument. 
Examples of such instruments with such fixed bends or curves in the rigid 
outer tube are described in U.S. Pat. Nos. 4,646,738--Trott and 
5,152,744--Krause et al. Both of these patents disclose a rigid outer tube 
with a predetermined bend therein which is placed and fixed in the 
instrument at the time of fabrication of the instrument. At least a 
portion of the inner tube for transmitting torque to the cutting blade is 
made flexible such that it freely rotates within the bend in the outer 
rigid tube. 
SUMMARY OF THE INVENTION 
The present invention provides a greater degree of flexibility in the 
performance of surgical procedures in a body cavity through a small 
incision. This instrument provides the surgeon with greater flexibility 
wherein surgical procedures may be performed more easily and more 
accurately with less discomfort to the patient. This enables the surgeon 
to more quickly and effectively perform the surgery, and enables more 
surgical procedures to be performed more effectively under local 
anesthesia. The instrument provides greater flexibility in any of the 
surgical procedures now commonly performed through a small incision, such 
as laparoscopic surgery, gynecological surgery performed vaginally, 
colonoscopic surgery and particularly arthroscopic surgery where it is 
often necessary for the instrument to be accurately placed in the curved 
spaces between the bones of the joint. 
In accordance with the method and apparatus of the present invention, 
greater flexibility is provided to the surgeon by enabling the surgeon to 
insert the instrument of the present invention into the body cavity, such 
as a joint, and visualize by means of a scope (such as the arthroscope, 
which may or may not be connected to a video display) the nature and 
location of the bend or curve to be placed in the instrument. The surgical 
instrument is provided with markings on the length of the instrument which 
enables the surgeon to note the precise location of the desired bends. The 
surgeon may then remove the instrument, make the necessary bends in the 
instrument and reinsert the instrument into the body cavity, such as the 
joint. 
Accordingly, in accordance with the present invention, the surgical 
instrument is constructed for insertion into the body for cutting, wherein 
it includes an outer member having at least one opening in a distal 
region. The surgical instrument includes a hollow inner member disposed 
within the outer member for transmitting force applied to a proximal end 
to move a cutting implement disposed at the distal end. The cutting 
implement is constructed and adapted to perform a cutting function at the 
opening in the outer member. The hollow inner member is flexible between 
its proximal and distal ends, and the outer member is provided with a 
predetermined flexibility and rigidity such that the outer member is 
provided with sufficient flexibility to be manually bent by a surgeon 
during the operation, and provided with sufficient rigidity to retain such 
bend during the continued performance of the operation with the surgical 
instrument. 
The method includes the steps of the surgeon inserting the instrument into 
the body, noting the location of the desired bends by observing the 
indicia on the outer surface of the outer member, retracting the 
instrument, performing the bends at the desired location and reinserting 
the instrument for the continued performance of the surgery.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings in detail, wherein like numerals indicate 
like elements, there is shown in FIG. 1 a flexible surgical instrument 10 
in accordance with the present invention. The surgical instrument 10 is 
intended and adapted to be utilized with a hand-held motor unit which is 
controlled by a foot pedal or other similar switching device which is well 
known in the field of arthroscopic surgery. For example, a motor and a 
foot pedal of one suitable type is shown and described in U.S. Pat. No. 
4,705,308--Sjostrom et al. The surgical instrument 10 is utilized in 
surgical procedures such as those which utilize surgical incisions at a 
joint for a fluid source, a scope connected to a camera and a hand-held 
motorized unit with a vacuum source, as illustrated and described 
generally in U.S. Pat. Nos. 4,203,444--Bonnell et al. and 
5,152,744--Krause et al. Although a video scope connected to a monitor for 
use as a video display is generally presently preferred, it is understood 
that the present invention may be utilized with any type of a scope or 
viewing device. 
The present invention provides the improvement wherein the entire length or 
substantially the entire length of the portion of the instrument 12 which 
may be inserted into the body for cutting is provided with a predetermined 
flexibility and rigidity such that its shape may be adjusted during the 
surgical procedure by the surgeon with the length 12 retaining this shape, 
curvature or bend for as long as is desired during the surgical procedure. 
The portion of the instrument 11, to the right of flexible length 12 in 
FIG. 1, is adapted to be inserted in or otherwise installed in a hand-held 
motorized handpiece which has a suction connection of one type 
conventionally available today. It is understood that the structure of 
portion 11 may be varied to be received in other types of hand-held 
motorized units. 
The flexible length 12 is comprised of an outer member or outer tube 14 and 
a hollow inner member or inner tube 16. The inner member 16 is hollow to 
enable the passage of fluid and tissue that has been cut to be withdrawn 
from the cutting area by suction or a partial vacuum. As used herein, the 
term "tissue" is understood to mean broadly all components of the body 
made up of cells and intercellular material, including not only soft 
tissue but also cartilage and bone. 
Outer member 14 may be constructed of any suitable material which provides 
sufficient flexibility and rigidity such that outer member 14 may be bent 
manually by the surgeon during the surgical procedure, and with sufficient 
rigidity such that the bend placed in outer member 14 is retained during 
the surgical procedure for so long as desired, with sufficient rigidity to 
maintain its shape and withstand the forces normally applied to it during 
such surgical procedures. Outer tube or outer member 14 may be constructed 
of a titanium alloy or a suitable plastic having memory. Outer member 14 
may be ribbed or recessed similar to that shown in FIG. 10, or may be a 
bellows structure similar to that shown FIG. 11. 
The inner member 16 may be constructed of any suitable material which 
provides sufficient flexibility to enable it to freely rotate within outer 
member 14, while having sufficient strength to transmit the forces from 
the proximal end 18 to the distal end 20. Inner member 16 must have 
flexibility along its length coextensive with the flexibility in outer 
member 14. Preferably, outer member 14 is flexible along its entire length 
or substantially its entire length, and accordingly, in a preferred 
embodiment, inner member 16 would be flexible along its entire length. 
Inner member 16 may be constructed of any suitable flexible material, such 
as a flexible plastic, or may be constructed of structures such as those 
illustrated for a portion of the inner tubular member in U.S. Pat. Nos. 
4,646,738--Trott and 5,152,744--Krause et al. 
A cutting implement 22 is disposed at the distal end 20 attached to hollow 
inner member 16 as illustrated in FIG. 2 by any suitable connection. As 
shown therein, the cutting implement 22 and inner member 16 may be 
form-fitted and adhesively bonded together at 17. 
Referring now to FIG. 4, there is shown an insertable flexible length 12 of 
an instrument with markings or indicia on its outer surface. The markings 
shown in FIG. 4 are the numerals 1 through 13. These may be arbitrarily 
placed on the instrument, or they may represent centimeters of length or 
other units of measurement. Further, the indicia may be any suitable 
indicia, including letters or other arbitrary symbols or markings of any 
type. Markings on the outer surface of outer member 14 are utilized to 
enable a surgeon to view and identify at what point along the length of 
insertable instrument the bend should be placed. 
As illustrated in FIG. 4, 12 represents a straight insertable length before 
bending, 12a represents the insertable length wherein a bend has been 
placed at approximately the location marked between the indicia 5 and 6. 
In a similar manner, the insertable length 12b illustrates the bend at the 
location between 5 and 6, and a more rounded bend located approximately at 
the 10-11 marking. It is understood that bends may be placed at any 
location along the length 12 as so desired by the surgeon. 
Multiple bends of any type or location may be placed in the length of the 
insertable instrument 12. For example, as illustrated in FIG. 1, there are 
bends at 24, 25 and 26. 
FIG. 5 illustrates two types of prior art instruments being utilized to 
perform a cutting function at an arcuatly shaped bone 28. Instrument 30 is 
a rigid straight instrument which presents problems, and instrument 32 
represents a rigid instrument with a fixed curve, such as that illustrated 
in U.S. Pat. No. 5,152,744, which again places limitations on the surgical 
procedure due to the fact that it has a single fixed curve which cannot be 
adjusted during the surgical procedure. 
Referring now to FIG. 6, there is shown an instrument utilized in 
accordance with the present invention wherein the outer member 12 may be 
shaped during the surgical procedure to go around the curved bone 28. 
FIG. 7 illustrates an implement in accordance with the present invention 
wherein the instrument may have two oppositely directed curves to enable 
it to be inserted through a single incision to reach various locations. In 
FIG. 7, there is a curve at 30 in one direction and a curve in the 
opposite direction at 32. The curves are of different radii of curvature. 
The present invention provides ultimate flexibility in shaping or curving 
the length of instrument 12 to that as desired during the surgical 
operation. The joints, bones and body cavities of different people are 
different. Accordingly, no one preset curvature is ideal for all 
operations on all people and animals. FIG. 7 also illustrates in dotted 
outline form wherein the instrument may be removed and rotated to access 
the other side of bone 28 or, alternatively, the instrument may be 
reshaped. 
Referring now to FIGS. 8 and 8A, there is shown a manually operable 
instrument 40 provided with a flexible length of insertable instrument 42. 
The outer member or outer tube 44 is provided with a sufficient degree of 
flexibility between its proximal end 48 and its distal end 50 to enable it 
to be manually bent or shaped by a surgeon during an operation, and with 
sufficient rigidity to retain such bend during the continued performance 
of the operation. As may be seen best in FIG. 8A, within outer member 44 
is an inner member 46 which may be a rod which provides the transmission 
of force between the handles 52 and the cutting implement 54. The inner 
member 46 may also be a solid or hollow flexible inner member which may 
transmit the force to cutting implement 54 by rotation. 
As illustrated in FIG. 8, instrument 40 is provided with a bend at 56. A 
second bend is shown in dotted outline form at 58. Any suitable bend may 
be provided to the instrument shown in FIG. 8. As may be seen in FIG. 8A, 
the outer surface of outer member 44 may be provided with indicia, such as 
the letters 45 illustrated in FIG. 8A, or any other suitable markings 
which may be utilized to aid in viewing the desired location of bends via 
the scope. The indicia, as stated above, may be numerals or line markings 
which may or may not be graduated. 
Referring now to FIG. 9, there is shown another embodiment of a manually 
operable instrument 60. Instrument 60 is provided with a length of 
insertable element 62 which has sufficient flexibility and rigidity such 
that element 62 may be manually bent by the surgeon during the operation, 
and has sufficient rigidity to maintain such bend or curvature during the 
operation for so long as desired. Element 62 is comprised of two slidable 
elements 62a and 62b. The force is transmitted from handle 72 at the 
proximal end 68 to cutting implement 74 at distal end 70. As illustrated 
in FIG. 9, the insertable length 62 is provided with a curve or bend at 
76, and another possible bend at 78. The outer surface of member 62 
(actually either or both the outer surfaces of 62a and 62b) may be 
provided with suitable indicia to aid in locating via the scope the 
desired location of bends to be placed as described with respect to both 
FIGS. 8A and FIG. 4. 
The insertable portions 42 and 62 of the instruments of FIGS. 8 and 9 would 
preferably be supplied without any bends, or in other words, straight. 
Bends 56 and 58 illustrated in FIG. 8 and bends 76 and 78 illustrated in 
FIG. 9 are preferably those which may be manually placed into the 
instrument during the surgical procedure. Alternatively, one or more bends 
might be provided in the instrument as manufactured. 
Although a presently preferred embodiment of the surgical instrument is for 
the entire insertable portion 12 to be flexible, it is understood that 
variations may be made wherein less than the entire length of member 12 is 
flexible. Where less than the entire insertable portion of the instrument 
is to be made bendable during the surgical procedure, this may be 
accomplished by either a change in the composition of the material or by 
the providing of a union wherein a portion of the length is rigid and 
another portion has the desired degree of flexibility. It will be apparent 
that other changes and modifications may be made to the surgical 
instrument within the scope and spirit of the present invention. 
In view of the foregoing, the present invention may be embodied in other 
specific forms without departing from the spirit or essential attributes 
thereof and, accordingly, reference should be made to the appended claims, 
rather than to the foregoing specification as indicating the scope of the 
invention.