Surgical instrument

A surgical instrument includes a tubular stem section which extends from a handle. A tubular articulated section connects a surgical instrument with the stem section. An actuator assembly is connected with the handle and is operable to bend the articulated section to change the orientation of an instrument on an outer end portion of the articulated section relative to body tissue. The instrument on the outer end of the articulated section may be a rotatable cutting tool which is driven by a tubular drive element having a flexible section which extends through the articulated section. The articulated section is bent or flexed by a plurality of flexible elongated elements (wires). In one embodiment of the invention, a pair of elongated elements are provided to flex the articulated section in opposite directions. In another embodiment of the invention, four flexible elongated elements are provided to flex the articulated section in any one of four directions.

BACKGROUND OF THE INVENTION

The present invention relates to a new and improved arthroscopic/endoscopic surgical instrument, and more specifically, to an arthroscopic/endoscopic surgical instrument which may be used to remove tissue from a joint or other body space.

Surgical instruments which may be used to remove tissue or perform other operations on tissue are disclosed in U.S. Pat. Nos. 4,499,899; 4,517,977; 4,649,919; and 4,834,729. The surgical instruments disclosed in these patents have stem sections which extend outwardly from a handle. A cutting tool or other device is disposed at the outer end of the stem section. The stem section is rigid. Therefore, the orientation of the cutting tool can not be changed relative to the stem section.

SUMMARY OF THE INVENTION

The present invention relates to a surgical instrument which is particularly well adapted for arthroscopic and/or endoscopic surgery. The surgical instrument has a stem section which is attached to a handle. A suitable instrument, such as a cutting tool, is connected with an outer end portion of the stem section by an articulated section. An actuator is provided to bend the articulated section to change the orientation of the instrument relative to the stem section and body tissue.

In one embodiment of the invention, a pair of flexible elongated elements, such as wires, are provided to bend the articulated section in opposite directions from an initial position. In this embodiment of the invention, the articulated section may be constructed so as to freely flex in a direction transverse to the direction in which the articulated section is bent by the elongated elements. In another embodiment of the invention, a plurality of elongated elements, such as wires, are provided to flex or bend the articulated section in any one of four directions.

DESCRIPTION OF SPECIFIC PREFERRED EMBODIMENTS OF THE INVENTION

General Description

A surgical instrument20, constructed in accordance with the present invention, is illustrated in FIG.1and may be used during the performance of arthroscopic and/or endoscopic surgery. A control apparatus22is connected with the surgical instrument20through a cord system24. The surgical instrument20includes a handle28of known construction, which is connected with a tubular stem section30. A known instrument32is connected with a rigid portion33of the stem section by an articulated section34constructed in accordance with the present invention.

In accordance with one of the features of the present invention, an actuator assembly38is manually operable to bend the articulated section34to move the instrument32between my one of many positions relative to the rigid portion33of the stem section30. The actuator assembly38can be operated to bend the articulated section34from a straight or initial condition shown inFIGS. 4 and 5to any one of a plurality of bent conditions, some of which have been indicated schematically in FIG.7. Thus, the actuator assembly38can be operated to bend the articulated section34upwardly from the straight or initial orientation (shown in solid lines inFIGS. 4,5and7) through a plurality of positions, indicated in dashed lines aid dash-dot lines to a fully flexed position indicated in dash-dot-dot lines in FIG.7.

Of course, operation of the actuator assembly38could be interrupted with the instrument32in any one of the positions illustrated inFIG. 7or in positions intermediate the positions shown in FIG.7. In addition, the actuator assembly38can be operated to deflect the articulated section34downwardly (as viewed inFIGS. 4 and 7) to any one of a plurality of positions. When the actuator assembly38has been operated to bend the articulated section34downward to a fully deflected position, the instrument32will extend straight downwardly in much the same manner as in which the instrument has been shown extending straight upwardly in dash-dot-dot lines inFIG. 7Thus, the actuator assembly38is operable to bend the articulated section34and to move the instrument32relative to the rigid portion33of the stem section30in such a manner as to change the orientation of the instrument32through 90° to either a straight upward orientation (as shown in dash-dot-dot lines inFIG. 7) or to a straight downward orientation.

In accordance with another feature of the embodiment of the invention illustrated inFIGS. 1-8, the articulated section34can be freely bent or deflected sidewardly, that is either up or down as viewed inFIG. 5or into and out of the sheet as viewed inFIGS. 4 and 7. Although the actuator assembly38is operable to positively deflect or bend the articulated section either up or down as viewed inFIG. 4, the articulated section34is allowed to float or bend sidewardly under the influence of forces applied to the articulated section.

The actuator assembly38can be operated to change the orientation of the instrument32relative to the rigid portion33of the stem section30and body tissue during an operation. The actuator assembly38can be operated to positively change the orientation of the instrument32through a range of 180°, that is through 90° upwardly (as viewed inFIGS. 4 and 7) from the straight initial orientation and through 90° downwardly (as viewed inFIGS. 4 and 7) from the straight initial orientation. In addition, the articulated section34can be deflected or bent under the influence of forces applied to the instrument32, through 90° to either side of the straight initial orientation shown inFIGS. 4 and 5.

It is believed that the surgical instrument20will be particularly advantageous for removing tissue from between vertebra in the human spinal column during an operation. Thus, the instrument32, articulated section34and part of the rigid portion33of the stem section30can be inserted through a very small opening in the skin adjacent to the spinal column of a patient. As this is done, the articulated section34is straight in the initial orientation shown inFIGS. 1,4and5.

After the stem section30has been partially inserted through an opening in the skin adjacent to the spinal column, the actuator assembly38is operated to bend the articulated section34and move the surgical instrument32transversely to a longitudinal central axis of the rigid portion33of the stem section30. This enables the instrument30to be moved to a desired position to engage tissue located between adjacent vertebra. As the instrument32is being moved by operation of the actuator assembly38, the articulated section34can also be deflected sideways under the influence of forces applied against the instrument32. Of course, the surgical instrument20can be used during the performance of many different types of arthroscopic and/or endoscopic operations.

During use of the surgical instrument20, it is contemplated that it will be desirable to convey tissue removed from between vertebra or other locations away from the instrument32. Accordingly, a suction pump (not shown) is connected with the handle28at a connection44. Suction is conducted through a central conduit or passage45(FIGS. 3 and 4) in the stem section30to the instrument32. The suction draws or pulls tissue from the area immediately adjacent to the instrument32back through the stem section30to the connection44and suction conduit

In addition, water or other fluid can be utilized to irrigate the area where tissue is removed by the instrument32. Thus, a source of water or other irrigation fluid is connected with the handle28at a connection indicated at46in FIG.1. The irrigation fluid is conducted through the handle28and the central conduit45in the stem section30to the instrument32. Irrigating fluid, along with the removed tissue, is then withdrawn from the area around the surgical instrument32.

Articulated Section

The articulated section34includes a plurality of relatively movable sections50,52,54and56(FIGS.4and5). The sections50,52,54and56are interconnected for pivotal movement about perpendicular axes. Thus, the section50is pivotal relative to the section52about a vertical axis indicated at60in FIG.4. The section50is connected with the section52at pivot connections62and64. Similarly, the section54is pivotal relative to the section56about a vertical axis indicated at66in FIG.4. The section54is connected with the section56at pivot connections68and70.

The section52is pivotal relative to the section54about a horizontal axis indicated at72in FIG.5. The section52is connected with the section54at pivot connections74and76. Similarly, the section56is pivotal relative to an end portion78of the rigid stem section33about a horizontal axis indicated at82in FIG.5. The section56is connected with the rigid portion33of the stem section30at pivot connections84and86.

The instrument32is pivotal relative to the section50about a horizontal axis indicated at92in FIG.5. The instrument32is connected with the section50at pivot connections94and96.

The axes60and66(FIG. 4) extend parallel to each other and perpendicular to a longitudinal central axis of the stem section30. Similarly, the axes72,82and92(FIG. 5) extend parallel to each other and perpendicular to a longitudinal central axis of the stem section30. The axes60and66extend perpendicular to the axes72,82and92. The axes60,66,72,82and92all intersect the central axis of the stem section30.

Initial operation of the actuator assembly38in one direction pivots the instrument32upwardly (as shown inFIG. 7) from the initial position shown in solid lines to the deflected position shown in dashed lines. Movement of the instrument32from the initial position shown in solid lines to the deflected position shown in dashed lines, is accomplished by pivotal movement of the instrument about the axis92at the pivot connections94and96(FIG.5).

Continued operation of the actuator assembly38pivots the sections50and52together while the instrument32is maintained in a deflected position. Thus, the sections50and52pivot upwardly from the initial position shown in solid lines inFIG. 7to the position shown in dash-dot lines in FIG.7. As this occurs, the sections50and52pivot about the axis72(FIG. 5) at the pivot connections74and76. During this movement, the orientation of the instrument32relative to the section50remains constant

Continued operation of the actuator assembly38pivots the sections54and56upwardly (as viewed inFIG. 7) from the initial position shown in solid lines to the position shown in dash-dot-dot lines. The instrument32and sections50and52are maintained in the same orientation relative to each other during this pivotal movement of the sections54and56. Thus, continued operation of the actuator assembly38pivots the sections54and56about the axis82(FIG. 5) at the pivot connections84and86.

During deflection of the articulated section34about the axes72,82and92(FIG. 5) by operation of the actuator assembly38, the articulated section34is also free to deflect sideways under the influence of forces applied against the articulated section. Thus, the section50and the instrument32are pivotal sideways relative to the section52about the axis indicated at60in FIG.4. The section50is pivotal sideways at the connections62and64. The sections50,52and54are pivotal sideways relative to the section56about the axis indicated at66in FIG.4. The section54is pivotal sideways at the connections68and70.

Actuator Assembly

The actuator assembly38includes a pair of flexible wires102and104(FIGS. 6 and 7) which are connected with the instrument32through the tubular stem section30. The wire102is connected with the upper (as viewed inFIG. 7) portion of the instrument32while the wire104is connected with the lower portion of the instrument32. The wires102and104are offset from the pivot connections94and96(FIGS.5and7).

Tension in the upper wire102(as viewed inFIG. 7) is effective to pivot the instrument32in a clockwise direction about the pivot connections94and96. Similarly, tension in the lower wire104is effective to pivot the instrument32in a counterclockwise direction (as viewed inFIG. 7) about the pivot connections94and96.

When the actuator assembly38(FIG. 6) is operated in one direction, the wire102shortens slightly and the wire104is lengthened to pull the instrument32from the initial position shown in solid lines to the position shown in dashed lines in FIG.7. Once the instrument32reaches the position shown in dashed lines inFIG. 7, further shortening of the wire102and lengthening of the wire104by operation of the actuator assembly38pulls the sections50and52in a clockwise direction (as viewed inFIG. 7) from the initial position shown in solid lines to the position shown in dash-dot lines in FIG.7. As this occurs, the section52pivots about the axis72at the connections74and76.

Continued operation of the actuator assembly38continues to shorten the wire102and lengthen the wire104. This results in the sections54and56being pulled in a clockwise direction (as viewed inFIG. 7) from the initial position shown in solid lines to the position shown in dash-dot-dot lines. As this occurs, the sections54and56pivot about the axis82(FIG. 5) at the connections84and86.

Operation of the actuator assembly38in the opposite direction is effective to shorten the wire104and lengthen the wire102. As the actuator assembly is operated in the opposite direction to shorten the wire104, the instrument32is pivoted downwardly or in a counterclockwise direction (as viewed inFIG. 7) about the axis92(FIG. 5) at the connections94and96.

Continued operation of the actuator assembly38results in further lengthening of the wire102and shortening of the wire104. This results in the sections50and52being pivoted downwardly or in a counterclockwise direction (as viewed inFIG. 7) about the axis72at the pivot connections74and76. Still further operation of the actuator assembly38to lengthen the wire102and shorten the wire104results in the sections54and56pivoting downwardly a in a counter-clockwise direction (as viewed inFIG. 7) about the axis82at the connections84and86(FIG.5). Thus, the articulated sections34can be deflected or bent either upwardly, in the manner shown inFIG. 7, or downwardly depending upon the direction of operation of the actuator assembly38.

The actuator assembly38has been shown schematically in FIG.6. The actuator assembly38includes a pair of pulleys or drams108and110to which end portions of the wires102and104are connected The wires102and104are wound in opposite directions about the drums108and110. The drums108and110rotate together about a common axis. Therefore, when one of the wires102or104is wound onto a drum108or110, the other wire is unwound from the other drum.

Upon pivotal movement of a handle114, a gear train116is actuated. The gear train116has been illustrated schematically in FIG.3. The gear train116includes a gear118which is fixedly connected with the handle114and a gear120which is fixedly connected with the pulleys or drums108and110(FIG.6).

Upon pivotal movement of the lever114toward the left or in a counterclockwise direction as viewed inFIG. 3, the gear120and drums108and110(FIG. 6) are rotated in a clockwise direction. Ibis results in the wire102being wound onto the drum108and the wire104being unwound from the drum110. As was previously explained, shortening or winding up of the wire102results in the instrument32being pivoted upwardly or in a clockwise direction as viewed in FIG.7.

Continued operation of the actuator assembly38results in continued shortening or winding up of the wire102and lengthening or unwinding of the wire104until the instrument32has been moved through 90° from the original orientation shown in solid lines inFIG. 7to the deflected orientation shown in dash-dot-dot lines in FIG.7. Since the wire104is wound around the drum110in the opposite direction from the direction in which the wire102is wound around the drum108, the wire104is lengthened as the wire102is shortened.

Pivotal movement of the handle114in a clockwise direction (as viewed inFIG. 3) rotates the gear120and drums1108and110(FIG. 6) in a counterclockwise direction. This results in the wire104being wound onto the drum110as the wire102is wound off of the drum108. Shortening of the wire104and corresponding lengthening of the wire102results in the articulated section34being pivoted downwardly or in a counterclockwise direction as viewed inFIG. 7in the manner previously explained.

It should be understood that although one specific preferred embodiment of the actuator assembly38has been illustrated schematically and described herein, it is contemplated that the actuator assembly38could have a somewhat different construction if desired Thus, many different types of mechanisms could be provided lengthening one of the wires102or104while simultaneously shortening one of the wires.

Regardless of the type of actuator assembly38which is utilized to deflect or bend the articulated section34, the actuator assembly is operable to apply force to the articulated section to deflect the articulated section from a straight initial configuration to an upwardly or downwardly (as viewed inFIG. 7) bent configuration. Thus, upon operation of the actuator assembly38, the articulated section34can be deflected in the manner shown in dashed, dash-dot and dash-dot-dot lines in FIG.7. This will result in the instrument32being moved upwardly from a position in which it is aligned with a horizontal Z axis (FIG. 8) to a position in which it is aligned with a vertical Y axis. The Z axis is coincident with a longitudinal central axis of the rigid portion33of the stem section30.

The actuator assembly38can also be operated to bend or deflect the articulated section34to move the instrument32downwardly from the Z axis into alignment with the Y axis in the manner shown in dashed lines in FIG.8. At this time, the instrument32extends downwardly from and perpendicular to the X and Z axes.

The actuator assembly38is operable to deflect the articulated section34to move the instrument32in either one of two directions, that is upwardly or downwardly as viewed inFIGS. 7 and 8. However, the articulated section34is deflectable to enable the instrument to be moved sidewardly. Thus, the articulated section34can be moved, under the influence of external or sidewards forces applied against the instrument32, to move the instrument from the initial position toward the left into alignment with the X axis as shown in dash-dot lines in FIG.8. Similarly, the instrument32can be deflected toward the right (as viewed inFIG. 8) into alignment with the X axis in the manner shown in dash-dot-dot lines. By a combination of operation of the actuator assembly38and sideward deflection of the instrument32, the articulated section34can be deflected in such a manner as to move the instrument32into almost any position within a hemisphere having a central polar axis which is coincident with the Z axis (FIG.8).

Instrument

In the embodiment of the invention illustrated inFIGS. 4 and 5, the instrument32includes a rotatable cutter124(FIG.5). The cutter124is connected with a drive shaft126(FIG. 3) of a motor in the handle28(FIG.1). During operation of the motor, the cutter124is rotated to cut tissue. Although the cutter124may have many different constructions, it is contemplated that the cutter my be constructed in a manner similar to that disclosed in U.S. Pat. No. 4,598,710.

Other known surgical instruments may be substituted for the cutter124. Thus, a generally spherical rotatable burr or muter may be used to abrade tissue. If desired, a probe or a basket biter having (mown constructions could be substituted for the cutter124. Of course, the particular type of instrument32which is connected with the outer end portion of the articulated section34will depend upon the surgical operation to be performed.

The cutter124is rotatable about the longitudinal central axis of the stem section30to cut tissue. A rigid tubular metal drive shaft128extends axially from the drive shaft126through the rigid portion33of the stem section30to the articulated section34(FIGS. 3,4and5). Since the articulated section34is capable of being deflected in any desired direction, the rigid drive shaft128stops short of the articulated section34and is secured to a flexible tubular polymeric drive shaft130(FIG.7). The flexible drive shaft130extends through the articulated section34and is connected to the rotatable cutter24.

The rigid drive shaft129is connected with the drive shaft126(FIG. 3) of a suitable electric motor in the handle28and is rotated about its longitudinal central axis by operation of the motor. The rigid drive shaft128is rotatably supported within a rigid tubular metal housing134by a plurality of spaced apart bearing or spacer blocks136(FIGS. 3,4and7). The bearing blocks136are disposed at spaced apart locations about the circumference of the drive shaft128. The bearing blocks136are fixedly connected with the stationary housing134and support the drive shaft128for rotation relative to the housing.

The wires102and104(FIG. 7) extend through space between adjacent tearing blocks136. It should be noted that suitable guides (not shown) are provided on the inside of the housing134to guide the wires102and104between the articulated section34and the actuator assembly38. Although many different types of known guides could be used, it is contemplated that it may be preferred to utilize guides having holes through which the wires102and104extend and which are formed of suitable polymeric material to minimize friction against the surface of the wires102and104.

The wires102and104are disposed radially outwardly of the rigid metal drive shaft128and the flexible drive shaft130. This allows the outer end portions of the wires102and104to be fixedly secured to diametrically, opposite portions of the instrument32in the manner indicated schematically at142and144in FIG.7.

Fluid for irrigating an area adjacent to the cutter124is conducted through the conduit45formed in the tubular rigid drive shaft128and the tubular flexible drive shaft130(FIGS. 3,4and5) to the cutter124. The suction draws the irrigating fluid and any loose tissue away from the cutter124.

It is contemplated that a thin flexible polymeric sheet my be provided around the articulated section34. However, the sheet has been omitted in the drawings for purposes of clarity of illustration

Second Embodiment

In the embodiment of the invention illustrated inFIGS. 1-8, the actuator assembly38is operable to bend the articulated section either upwardly or downwardly from the Z axis in the plane of the Y axis (FIG.8). However, the articulated section34is constructed so that it is deflectable or bendable by forces applied to the instrument32or the articulated section34to deflect the instrument32to either side of the plane of the X and Z axes, in the manner indicated schematically in FIG.8.

It is contemplated that it my be desirable to have the actuator assembly38constructed in such a manner as to be operable to bend the articulated section34in any desired direction. An embodiment of the invention having an actuator assembly constructed so as to deflect the articulated section34in my desired direction is illustrated in FIG.9. Since the embodiment of the invention illustrated inFIG. 9is generally similar to the embodiment of the invention illustrated inFIGS. 1-8, similar numerals will be utilized to designate similar components, the suffix letter “a” being associated with the numerals ofFIG. 9in order to avoid confusion.

In the embodiment of the invention illustrated inFIG. 9, a surgical instrument20a has a handle28a which is connected with an instrument32a by a stem section30a. The stem section30a includes a rigid section33a and an articulated section34a.

In accordance with a feature of this embodiment of the invention, an actuator38a is provided to move the instrument32a in a plane containing the Z and Y axes (FIG.8). A second actuator assembly152is provided to move the instrument32a in the plane containing the X and Z axes (FIG.8). Thus, the two actuator assemblies38a and152function as an actuator system which enables a surgeon to move that instrument32a anywhere within a hemisphere by operating the actuator assemblies.

The actuator assembly38a is connected with the instrument32a by wires102a and104a. The actuator assembly152is connected with the instrument32a by wires156and158. The wires102a,104a,156and158are connected with the instrument32a at locations which are offset from each by 90° about the circumference of the instrument32a. The wires102a and104a are connected with the instrument32a at locations which are diametrically opposite from each other. The wires156and158are connected with the instrument32a at locations which are located diametrically opposite from each other and on a diameter which extends perpendicular to a diameter extending through the connections of the wires102a and104a to the instrument32a. The combination of the four wires102a,104a,156and158and the actuator assemblies38a and152enable the instrument32a to be pivoted in my desired direction relative to the rigid stem33a.

In the embodiment of the invention illustrated inFIG. 9, the actuator assembly152has the same construction as the actuator assembly38a. However, it is contemplated that it my be desirable to combine the functions of the actuator assemblies152and38a into a single actuator assembly which would operate all four wires102a,104a,156and158. However, it should be understood that the two actuator assemblies39a and152cooperate and function together in such a manner so as to enable a surgeon to move the instrument32a in my desired direction from the initial position shown in FIG.9.

Conclusion

The present invention relates to a surgical instrument20which is particularly well adapted for arthroscopic and/or endoscopic surgery. The surgical instrument20has a stem section30which is attached to a handle28. A suitable instrument32, such as a cutting tool, is connected with an outer end portion of the stem section30by an articulated section34. An actuator38is provided to bend the articulated section34, to change the orientation of the instrument32relative to the stem section30and body tissue.

In one embodiment of the invention, a pair of flexible elongated elements102and104, such as wires, are provided to bend the articulated section23in opposite directions from an initial position. In this embodiment of the invention, the articulated section34may be constructed so as to freely flex in a direction transverse to the direction in which the articulated section is bent by the elongated elements102and104. In another embodiment of the invention (FIG.9), a plurality of elongated elements102a,104a,156and158, such as wires, are provided to flex or bend the articulated section34a in any one of four directions.