JPS6216102B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to orthopedic instruments, and more particularly to instruments capable of performing arthroscopic visual intra-articular joint arthroplasty. Intra-articular refers to a living joint such as a knee, arthroplasty refers to shaping or modifying the joint surface, and arthroscopy refers to visual observation using a deep needle inserted into the joint through an opening, and surgical treatment of the joint. Do not make any incisions.

Although it has been known for several decades that joints in the human body can be visualized through the insertion of a deep needle or endoscope, joint surgeries are primarily performed by open surgery. In standard knee surgery, relatively large incisions are required, even when the purpose of the surgery is to remove small amounts of cartilage or bone. This is because the surgery itself causes trauma, resulting in a long treatment period and discomfort.
This can lead to exercise restrictions.

When planning an arthroplasty by closed surgery of the knee or other joint spaces, many and sometimes contradictory requirements arise. For example, the device must be small, maneuverable, enter the joint, and
Requires size for force transmission and removal material extraction. It requires safety to avoid unintentional action on the joint surface, and strong cutting action when required. Additionally, it must be highly reliable and safe to use by orthopedic surgeons of various levels of skill.

A known example of an arthroscopic surgical instrument is U.S. Pat.
No. 4203444, which is an extremely effective intra-articular ablation device for its intended use, but cannot be used in joint arthroplasty procedures that require the removal of bone.

For regeneration of articular surfaces, when the thin covering of articular cartilage that acts as a low-friction load-bearing surface on the cartilaginous surfaces of the tibia and femur degenerates, e.g. in the case of degenerative joint points, There is a proposal to drill holes to a depth of 3 to 4 mm into the subchondral bone at multiple points, expose the vascular bed, and promote the production of fibrocartilage to regenerate the joint surface.

In other examples, scrapers are used for the same purpose, but with negative changes in surface shape.

With the present invention, instead of the known deep and distant drilling and strong scraping, the articular surface can be drilled over a wide area with a depth of 0.5 to 1 mm.
To some extent, good results are obtained by removing or ablating the arthroscope in direct view of the surgeon using a rotating semi-shielded cartilage and bone ablation instrument.

The arthroscopic abrasion instrument of the present invention enables arthroplasty under arthroscopic control, the instrument is small and maneuverable, and can enter narrow joints to abrade cartilage and bone. can transmit the force necessary to
The removed material is removable, allowing arthroplasty through only a small puncture.

Specifically, the present invention is a surgical instrument for arthroscopic arthroplasty that is inserted into a joint through a drill hole and, under direct visual control of the arthroscopic surgeon, removes the degenerated cartilage of a load-bearing articular surface. remove the bone,
By exposing the rich vasculature beneath the hardened bone surface,
It allows fibrosis and healing by the blood supplied by the vascular bed, thus allowing the production of fibrocartilage covering the load-bearing articular surfaces. The instrument includes an outer tubular sheath, a support member for securing the sheath, and an inner tubular shaft extending within the outer sheath, wherein the surface of the abrasive element supported at the front end of the inner tubular shaft rotates to rotate the articular surface. The shape of the outer sheath exposes a limited portion of the abrasive element to perform the abrasive action;
The outer sheath acts as a protective shield, helping the grinding element to cut to a limited depth within the articular surface, and also serves as a shield to prevent the grinding element from coming into contact with the articular surface from other directions. at least one hollow annular front portion, the end being connectable to a vacuum source to expel liquid and entrained abrasive material through the tubular shaft, and having a device for rotating the inner tubular shaft, the shaft relative to the outer sheath; A bearing member is provided, the abrasive element receives a lateral load during abrasive engagement with the articular surface, and the inner tubular shaft communicates through the bearing to a fluid opening anterior to the bearing member to receive fluid and abrasive material. and can be discharged through the bearing.

A preferred embodiment is as follows. Spaced apart front and rear bearing surfaces are provided, the front bearing member being a radially extending annular surface that rotates with the inner tubular shaft; the outer sheath is shaped to expose a limited portion of one side of the abrasive element. the shape of the outer sheath exposes a limited portion of the end of the abrasive element; the shape of the outer sheath exposes a limited portion of one side and a limited portion of the end for the abrasive action of the abrasive element; The front end of the outer sheath is cut diagonally along one side to gradually expose one side of the abrasive surface of the abrasive element; the front end of the shaft is located proximate the end surface of the abrasive element; the exposed side of the outer sheath approximately coincides with the bony wall of the outer sheath; cut the outer sheath along a line in the plane at a 30° angle to the sheath axis; connect the instrument to an external vacuum source and the inner tubular shaft Fluid and accompanying abrasive tissue and bone are expelled from the joint at a flow rate of at least 100 c.c./min; a drive spool is formed at one end of the abrasive element, and the drive spool is axially attached to the anterior end of the inner tubular shaft. The front end of the inner tubular shaft is removably supported; the chuck member is hollow and has a receiving device for receiving and fixing the driving spool between the articulating surfaces of the grinding element; the front end bearing is provided near the receiving device of the chuck member; extending annularly from the outer wall of the chuck member and providing a hole in the annular wall of the chuck member, with the hole proximate the receiving device and forward of the bearing, and the chuck member serving as a conduit for fluid and entrained abrasive tissue within the front bearing and the chuck member. through the inner tubular shaft to communicate with the inner tubular shaft conduit for draining fluid from the body; a locking device is provided on the inner annular shaft to receive and lock the front end of the abrasive element drive spool to prevent the drive spool from slipping out during surgery; The grinding element and the drive spool are integrally formed; the outer tubular sheath has a length of about 4 mm with a length of about 50 mm or more.
The diameter of the inner tubular shaft should be between 500rpm and 3000rpm.
The rotating device is reversible under the surgeon's control; the abrasive element makes a smaller cut when reversing than when rotating forward.

The device of the present invention can be used in addition to the specific arthroplasty procedures described above. For example, this may occur when the articular cartilage has a defective or irregular surface, or when an irregularity is formed in the cartilage during other intra-articular surgery. The devices of the present invention are effective in smoothing and shaping surface imperfections to reduce patient pain and improve patient joint mobility.

In a completely different field, for removing objects from the human body, especially for removing objects in the eye, such as cataract lenses, the abrasive instrument is provided with an adjustable tubular device to control the exposure of the abrasive cutting edge. This is described in US Pat. No. 3,937,222.

Embodiments and drawings illustrating the structure and operation of the present invention will be described.

The instrument 10 shown in FIGS. 1 and 2 is inserted into the knee joint and acts on the low-friction, load-bearing articular surfaces of the tibia 6 and femur 8. At the same time, fiber optic device 4 directs light from light source 12 into the joint and returns a visible image along another light path. Although the image could be directed to the surgeon's eyepiece and recording camera, in the preferred embodiment shown, the image is directed to a television camera 16 to produce a display 18 that is viewed by the surgeon to control surgical movements. By looking at the screen and operating the device, the device moves along the joint surface.
The joint surfaces are ground and this is shown on the television screen.
Details of the screen will be described later with reference to FIGS. 10 and 11.

During surgery, physiological saline is supplied from water source 2 at controlled water pressure to inflate the joint.

The success of the device depends on the important features of the structure according to the invention, as mentioned above. As shown in FIGS. 2, 2a and 3, an outer tube 2 of a device 10 according to a preferred embodiment
0 has an outer diameter of 7.5 mm and an inner diameter of 6.4 mm, and the inner tube 24, which is extendably inserted into the outer tube 20, has an outer diameter of 5.2 mm and an inner diameter of 4.4 mm.
mm. The inner tube 24 is rotated relative to the outer tube 20, and the drive device is shown in FIG.
54 is mounted within the handle 50 and engages the drive projection 28 shown in FIG. The motor 54 can be reversed by controlling a foot switch 55 or the like by the surgeon.
The torque value generated by the motor 54 is approximately 2.88 kg cm, and the grinding element is rotated at approximately 500 rpm under normal bone grinding load.
Rotate at a maximum of approximately 3000 rpm.

In Figures 2a, 3, 4 and 5, a chuck 30 is fixed to the tip of the inner tube 24. The chuck 30 is a separately molded unit and is axially secured to the inner tube 24 by epoxy adhesive. Check 3
0 receives and holds the drive spool 42 of the abrasive element 40, providing a secure hold against the forces exerted during engagement of the instrument with the articular surface. To this end, an axial cut 34 is formed in the wall 32 of the chuck 30 made of heat-treated stainless steel to permanently form a leaf spring-like lock 36. Deformed portion 38 on wall portion 32
is formed to serve as an alignment guide. Grinding element 4
A grinding head 44 is provided at 0, and in the example shown, the diameter
The diameter is 5.5 mm, and the cutting edge has 12 spiral grooves on the ground surface. Drive spool 42 of head 44
The diameter was 2.4 mm and the length was 10.3 mm. The configuration of the helical cutting edge is such that the depth of cut of the abrasive element is large when rotating in the forward direction, and small when rotating in the reverse direction. The head 44 and spool 42 are fabricated from a single piece of heat-treated stainless steel to resist rupture under the forces exerted during surgical procedures, such as lateral bending pressures on the order of 170-340 kg/cm ² . This abrasive element is for one-time use and a new sharp blade can be used for each surgery. The drive spool 42 is provided with an axial notch, which serves as an alignment flat portion 52, a locking flat portion 54, and an alignment guide gap 56, as shown in FIGS. Annular notch 58 in spool 42
is formed at the free end to facilitate insertion into the chuck. To prepare the instrument for use, the drive spool 42 is lightly inserted into the end of the chuck 30, the abrasive element is gently rotated to align the alignment guide 38 with the alignment flat 52, and the spool 4 is
2 into the chuck 30. The abrasive element 40 is pushed axially into the chuck so that the catch 36 is within the catch flat 54, with the shoulder of the chuck 30 contacting the shoulder of the abrasive element 40. In this position, the grinding head 44 is fixed on the inner shaft 24 and
Withstands all forces acting during surgical procedures. To remove the grinding head it is necessary to use the tool shown in FIG. The abrasive head 44 is passed through the aperture 62 and the aperture 64 contacts the circumference of the chuck 30.
A force is applied in the direction shown by arrow A to pull the spool 42 out of the chuck 30. The abrasive element is discarded and a new element inserted. The inner tube 24 and the outer tube 20 are normally disassembled to attach and remove the grinding elements.

When assembled, the grinding head 44 axially projects approximately 1 mm from the front end of the outer tube 20. As standard, the outer tube 20 has a length of at least 50 mm. The front end of the outer tube 20 is at an angle to the axis of the tube along one side;
In the illustrated example, the cut is made at 24 degrees to sequentially expose the side surface 80 of the grinding head 44 at a position that coincides with the outer wall 82 of the outer tube. This sequential taper is shown in cross section in Figures 12-12b.

A force acting on the abrasive element 44 at an angle, substantially perpendicular to the drive axis, supports the inner shaft 24 against radial bending under bone abrasive loads. There is a need. A front end annular bearing 90 that provides this support is fixed to the outer wall 31 of the chuck 30 at a position near the front end of the outer tube 20, and a rear end annular bearing 92 is fixed to the wall of the inner shaft 24 and supported at the rear end. Both bearings rotate together with the inner shaft 24 and support the shaft 24 against the inner wall of the outer tube 20. Furthermore, by providing the above-mentioned bearing, the frictional drag of the instrument is low.
The required torque, approximately 2.88 Kg·cm, can be supplied to the grinding element. This torque is intentionally capped to avoid the risk of overload conditions.

Drive spool locking portion 36 on the wall of chuck 30
A hole 70 is provided in the vicinity of the hollow chuck 30, and the hole 70 is provided in a passage from the hollow chuck 30 to the inner shaft 24 via the front end bearing 90.
0 and communicates with a vacuum source 45 to remove any abraded tissue from the joint. The vacuum source 45 is external to the instrument, typically a wall-mounted vacuum device in the surgical equipment;
Normally, the mercury column is about 350 to 400 mm. The vacuum value is controlled manually by valve 43.

As another example of the same configuration, the outer diameter of the outer tube 20
The inner diameter of the grinding element is 5.7mm and the inner diameter is 4.7mm, and the inner tube 24 that can slide inside it has an outer diameter of 4.2mm and an inner diameter of 3.8mm.
Set it to 4.0.

The operation will be explained.

During the surgical process shown in Figure 1, the patient was given hemp vinegar all over the body,
The required holes are made with a trocar cannula at selected points near the joints of the patient's muscles. Fluid is introduced from source 2 into one cannula at slightly higher pressure to inflate the joint, passing through the joint to instrument 10.
This causes a flow to flow into the suction port 70 of the. The flow rate should be greater than 100 c.c./min to ensure that all material abraded from the joint is sucked into the instrument 10 and removed from the joint. Additionally, intra-articular fluid is clarified to facilitate visual guidance of instruments.

Visual instrument 4 is inserted into the joint via another cannula. The instrument 10 shown in FIG. 2 is inserted into the third cannula.

The fluid supplied from the fluid source 2 into the joint cavity flows through the abrasive element surface into the annular space 21 between the chuck 30 and the front end of the outer tube 20 and from there through the opening 70 in the wall of the chuck 30. pass through. Check 30
The internal space 71 allows the liquid to flow through the front end bearing, enter the passage 72 formed by the inner tube 24 and discharge through the rear end bearing 92 into the drainage chamber 74 . room 74
is connected within housing 42 to a vacuum source 45 . Due to the shape of the drainage chamber 74, suction is maintained continuously during the rotation of the abrasive element 40.

The surgeon inserts the instrument into the joint with the motor stopped. The fluid source 2 and vacuum source 45 are balanced so that the same amount of fluid introduced into the joint is expelled through the instrument, keeping the inlet pressure at a slightly higher pressure and inflating the joint to the desired degree.

The flow path and the operating part of the device are designed to perform the required operation when the device is connected to a suction negative pressure source (approximately 350 to 400 mm of mercury).

As shown in Figure 10, the instrument is inserted into the tibia 6 and femur 8.
into the narrow space 100 between the condylar surfaces (i.e., dimension B is approximately 8 mm) and abrades the thin layer of cartilage 102 and the underlying condylar bone. Although the illustrated example abrades a thin cartilage layer and bone depth in one pass, the bottom 82 of the outer tube 20 can be used as a control fulcrum to abrade shallower tissue in a single pass. It can also be controlled. Only one side and a portion of the end of the abrasive head 44 are exposed from the tapered end of the outer tube 20 and contact the cartilage surface 102, and the rear side portion of the abrasive surface is shielded by the outer tube. Prevents accidental contact with surrounding joint tissue.

Thus, as the load-bearing cartilage of the joint degenerates into rotating semi-shielded cartilage, the bone abrasive head 44 of the instrument moves across the articular surface at the focal site, i.e. the diseased area.
removing the thin covering layer of articular cartilage and the thin layer of bone;
Remove the subchondral bone to a depth of approximately 0.5-1.0 mm. This creates a smooth surface 104 that normally exposes the vascular bed and allows even production of fibrocartilage over the articular surface.

The present invention is capable of various modifications. For example, the shape of the grinding element may be an ellipse, a cylinder, or the like, and the grinding element may have a grinding surface other than that shown, or a relatively smooth surface.

The instruments of the invention can be used in other surgical procedures for arthroplasty, such as smoothing defects or irregularities in other cartilage surfaces.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an instrument for performing intra-articular arthroplasty of the knee and the device of the present invention, and FIG.
Figure 2a is an enlarged vertical cross-sectional view of the rear end of the instrument, Figure 3 is a longitudinal cross-sectional view of the front end as seen from the bottom side of Figure 2a, and Figure 4 is Figure 2a. 5 is an enlarged partial sectional view of FIG. 3; FIG. 6 is a side view of the abrasive element used in the instrument;
7 is a right end view of FIG. 6, FIG. 8 is a plan view of FIG. 6, FIG. 9 is a side view of a tool for removing the grinding element of FIG. 6, and FIG. 10 is a joint formed by the instrument of the present invention. 11 is a plan view of FIG. 10; FIG. 12, FIG. 12a;
Figures 12b and 12b are 12-12 of Figure 5, respectively.
12a-12a and 12b-12b; FIG. 6... Tibia, 8... Femur, 10... Surgical instrument, 2... Fluid source, 20... Outer sheath, 24
... Tubular shaft, 40 ... Grinding element, 45 ... Vacuum source, 70 ... Opening, 80 ... Grinding surface, 90, 92
... Bearing, 102 ... Articular surface, 140 ... Arthroscope, 154 ... Motor.

Claims (1)

Claims: 1. An inner drive shaft 24 which is laterally supported on its tip side and has an abrasive element 40 at its end; a fixed outer tubular member 20 providing lateral support; a distal extension of the outer tubular member providing shielding for a portion of the abrasive element; a vacuum passageway extending from the region of the element through the bearing region toward the rear end and communicating with the vacuum connection at the rear end, thereby driving the drive shaft and connecting the Surgical instrument characterized in that upon introduction of negative pressure through the section, the parts removed by the driven abrasive element are ejected from the instrument through the bearing area. . 2. The surgical instrument of claim 1, wherein the drive shaft is a hollow inner tube, and a hollow inner tube adapted to removably grip and drive the abrasive element. a chuck member 30 attached to the tip of the tube;
an inlet device 7 provided at the distal end of the chuck member for allowing entry of the piece into the inner tube;
0, wherein an inner tip portion of the inner tube communicates with the vacuum connection. 3. The surgical instrument according to claim 2, wherein the inlet device is provided on the distal end side of the bearing region. 4. The surgical instrument of claim 1, wherein the tubular extension of the outer tubular member and the abrasive element are dimensioned to be inserted externally through an opening in the flesh of a living body; Surgical instrument, characterized in that the abrasive element is of sufficient length to extend into the position of the working surface while the instrument is guided by a visual device. 5. A surgical instrument according to claim 1, wherein the instrument is adapted to be connected to an external vacuum source and to deliver a fluid carrying ablated tissue from the region at least per minute. A surgical instrument characterized in that it has the ability to discharge at a flow rate of about 100 cubic centimeters. 6. The surgical instrument according to claim 1, wherein the drive shaft rotates at a speed of at least about 500 rpm under normal load. 7. The surgical instrument of claim 1, wherein the drive shaft is rotated in forward and reverse directions by operation of the surgeon, and the abrasive element rotates in the reverse direction more than in the forward direction. 1. A surgical instrument characterized by being adapted to be more passively abrasive. 8. The surgical instrument according to claim 1, wherein the extension of the distal end of the outer tubular member gradually decreases along one side to gradually expose the surface of the abrasive element from one side. A surgical instrument characterized in that the distal end of the outer tubular member terminates on the rear end side of the end surface of the abrasive element. 9. The surgical instrument of claim 8, wherein a line extends in a plane in which the outer tubular member is disposed at an angle of 30° or less to the axis of the tubular member. A surgical instrument characterized in that it gradually decreases along the line.