Forceps for performing endoscopic or arthroscopic surgery

Forceps for performing endoscopic or arthroscopic surgery include a body assembly, a tube assembly, and a pair of handles that pivot with respect to the body. The tube assembly is removably attached to the body assembly. The tube assembly includes a hollow tube and a tip assembly. The tip assembly includes an electrode or a blade for performing the surgery. The tip assembly and the blade are connected to the body and the handles by a cable. As the handles pivot, the cable slides within the tube to move the blade. When a different tube assembly (i.e., a bipolar or a monopolar electrode) or another style of tip assembly are desired, the installed one is removed and replaced by a new tube assembly or tip assembly as desired.

BACKGROUND OF THE INVENTION

Today's endoscopic and arthroscopic surgical instruments encompass a multitude of different designs. While all may be designed to serve the same function, for example, each one may be shaped differently to provide the surgeon better access to perform the procedure. For example, a pair of forceps may include a tube that extends from a pair of handles. A blade is disposed at an end to the tube for performing the surgery. The tube, near the blade in one pair of forceps is bent upward to provide the surgeon with the required access in the patient to make a first cut. However, if the surgeon needs to perform a second cut, on the same patient, but in a different position, the surgeon must get a different pair of forceps where the tube is bent to a different orientation.

Based on the above, it is easy to relate to today's realities of the operating room where a large inventory of specific instruments must be kept in an inventory at a high cost. Managing and maintaining this inventory is costly and complex. Lack of flexibility among the instruments are a direct added cost to each surgery, while maintaining the different variety of instruments necessitates trained personnel and sterilization facilities and capabilities.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the Figures, wherein like numerals indicate like parts throughout the several views, forceps are generally shown at40. Forceps40are used for performing various procedures during endoscopic or laparoscopic types of surgery. A common type of procedure is cutting. However, they can be used to perform other types of procedures such as grasping, manipulating, or ablating, for example.

The forceps40include a body assembly42, a tube assembly46, and a pair of opposing handles48,50. The handles48,50include an upper handle48and a lower handle50. The handles48,50are pivotally connected to the body assembly42. A handle screw52attaches each handle to the body assembly42but allows the handles48,50to pivot. Teflon washers54may be interposed between each of the handles48,50and the body assembly42for reducing friction when pivoting each handle48,50with respect to the body assembly42.

The tube assembly46, shown inFIG. 4, includes a hollow tube56extending between an adapter58and a tip assembly60along a tube axis DD. The adapter58encircles the tube56and defines a plurality of locking holes or indentations62in grooves63encircling the adapter58. The tube56and the adapter58each define a hollow interior59. A flushing port66is formed in and extends from the adapter58. The flushing port66defines a duct68into the hollow interior59of the adapter58for flushing the tube assembly46. A cable70is connected to the blade90via pin83and extends through the tube assembly46and out beyond the adapter58.

The tip assembly60, shown inFIGS. 2 and 3, extends from a distal end71of the tube56for performing the cutting procedures. The cable70, shown inFIGS. 10-13, extends through the tube56and interconnects the tip assembly60to the handles48,50. The cable70is flat or having at least flat end portions, having a thickness T, and extending between a blade end74and a cable end76. The blade end74is disposed in the body134proximate the tip assembly60, as shown inFIG. 14. The cable end76is disposed in the body assembly42, proximate the handles48,50. The cable70tapers to a reduced width W before each of the blade end74and the cable end76. The blade end74extends from the reduced width W and has a generally trapezoidal shape with a front sloping edge78and a top edge79. The blade end74defines a shoulder80, opposite the front sloping edge78and adjacent the reduced width W. The blade end74defines a tip pinhole83. The cable end76has a generally rectangular shape that extends from the reduced width W. The cable end76defines a shear pinhole84. A cable retainer86, for mounting to the cable end76, is generally bullet shaped with a round cross-section, as shown inFIGS. 23-25. The cable retainer86defines a shear pin hole84. A slot85is defined in the cable retainer86that is at least equal in size to the thickness T of the cable70. The cable retainer86also defines a shear pinhole84that extends through the slot85. The thickness T of the cable end76is inserted into the slot85and the shear pin holes84are aligned along the same axis. A shear pin88is inserted through the shear pin holes84to retain the cable retainer86onto the cable end76.

The tip assembly60includes a blade90and a tip92. The blade90, shown inFIGS. 5-7, is a single-acting blade90that pivots relative to the tip92to perform the cutting procedure. However, the present invention is not limited to a single-acting blade90, but may also be double-acting blades90, or even jaws, where the elements pivot relative to one another. The blade90is flat and is generally rectangular in shape. The blade90is bounded by a bottom surface94, an upper surface96, a front98, and a rear100. The bottom surface94of the blade90defines a concave cutting region102. The upper surface96of the blade90, opposite the bottom surface94and the cutting region102, is rounded toward a front98of the blade90. The rounded upper surface96and the concave cutting region102give the blade90the appearance of a “claw”. The rear100of the blade90defines a blade cavity106that extends into the blade90. The blade90also defines a tip pin hole82and a cable pin hole83extending through the blade90and the blade cavity106. Finally, the blade90includes a first blade stop107and a second blade stop109extending between the bottom surface94and the upper surface96.

Referring toFIGS. 8 and 9, a tip92includes a shaft108that extends between a cylindrical neck110and a cutting portion112. The shaft108has a diameter H. The neck110has an external diameter D which is less than the diameter H of the shaft108. The neck110defines at least one external circumferential grooves114that encircle the neck110. The neck110is engaged when inserted into the distal end71of the tube56for retaining the tip assembly60to the tube56. The neck110can be attached to the shaft108by brazing, laser welding, adhesives or soldering, for example. When the shaft108is soldered to the tube56, a soldering compound is applied to the grooves114and surface110. Additionally, an adhesive can be applied in the grooves114and surface110prior to inserting the neck111into the distal end71of the tube56. As yet another alternative, the neck111can be press-fit into the distal end71of the tube56. The cutting portion112extends from the shaft108, opposite the neck110. The tip92is formed from a circular rod and includes a top surface116that slopes forward to the cutting portion112to provide the cutting portion112with a height less than the diameter H of the shaft108. The width of the cutting portion112is smaller or equal to the diameter H of the shaft108. The cutting portion112and a portion of the shaft108define a cutting opening118that is generally rectangular in shape. The neck110and shaft108define a cable opening120that extends into the cutting opening118to form a single continuous tip chamber122. The cutting opening118, proximate a front124of the tip92, defines a front curved surface126. The cutting opening118, proximate the neck110and the cable opening120, defines a rear curved surface128. A hip130is formed on the rear curved surface128, along the bottom of the tip92for providing a stop for the shoulder80of the cable70.

The shaft108, proximate the cutting portion112, also defines a tip pin hole82that extends though the shaft108and the hollow interior59. The blade end74of the cable70is inserted into the hollow interior59and the cable pin holes83of the cable70and the blade90are aligned. Additionally, the tip pin holes82of the blade90and the tip92are aligned. The blade90is assembled to the blade end74and a cable pin132is inserted through the aligned cable pin hole83to pivotally connect the blade90to the cable70. Likewise, the blade90is assembled to the tip92by inserting the blade90within the hollow interior59between the tip pin holes82of the tip92and a tip pin133is inserted through the aligned tip pin holes82to pivotally connect the blade90to the tip92. Because the tip92is connected directly to the tube56, the tip92remains stationary. When the handles48,50are moved relative to one another, the blade end74is moved fore/aft inside the hollow interior59, by virtue of sliding the cable70inside the tube56, the cable pin hole83slides fore/aft relative to the tip pin hole82, which remains stationary. Therefore, the movement of the cable pin hole83, relative to the fixed tip pin hole82, causes the blade90to pivot about the tip pin133while moving the cutting member into and out of the hollow interior59of the tip92. Movement of the cutting member relative to the cutting surface enables the cutting procedure to occur.

The body assembly42, shown inFIG. 14, includes a body134and an arm136extending from the body134. The body assembly42defines a passage138extending through the body134and the arm136along a common axis. The body134defines a chamber140, which is circular, along the passage138. The arm136defines a collet chamber142, which is also circular, along the passage138. The diameter of the collet chamber142is a smaller diameter than the diameter of the chamber140and extends to a threaded portion143and a locking nut197. Rests144are formed on the outside of the arm136for providing a stop for each of the handles48,50. The body assembly42includes an upper surface96that defines a threaded hole146extending to an opening148. The opening148extends between the threaded hole146and the chamber140on a locking axis BB.

A lock150is disposed in the opening148. The lock150includes a base152that is sized to fit within the opening148. A locking pin154depends from the base152for engaging a corresponding locking groove62on the tube assembly46. A locking ramp156that slopes from near a top158of the base152toward the locking pin154is formed on opposite sides of the base152. The body134also defines a locking hole160that intersects the opening148. A spring cap162is threadedly engaged with the threaded hole146. The spring cap162compresses and retains a spring164between the spring cap162and the lock150to bias the lock150toward the chamber140. The spring cap162may define an orifice199for receiving a portion of the spring164. Additionally, the lock150may define a spring pocket159for receiving a portion of the spring164. The spring pocket159and the orifice199help to maintain the spring164in the position as it is compressed and released.

A release plunger166, shown inFIGS. 15-18, includes a plunger shaft168disposed between a head170and an end172. The plunger shaft168is disposed in the locking hole160along a plunger axis AA. The plunger shaft168is generally rod shaped and defines a slot177extending through the plunger shaft168and a plunger ramp174, formed in the plunger shaft168, adjacent and sloping toward the end172. When the plunger166is disposed in the locking hole160, the plunger ramp174opposes the locking ramp156and the locking ramp156imparts a force on the plunger ramp174along the locking axis BB. The locking ramp156and the plunger ramp174slope relative to the locking axis (lateral axis) BB, in opposite directions such that the plunger ramp174is opposed and slidable engages a surface of the locking ramp156.

When the release plunger166is pushed along the plunger axis AA, toward the body134, the plunger ramp174moves along the locking ramp156and pushes the lock150upward and away from the plunger166, along the locking axis BB. When this happens, the locking pin154disengages the locking groove62of the tube assembly46. When the locking pin154is disengaged from the locking groove62, the tube assembly46is free to be rotated within the chamber140of the body134and align a different locking groove62with the locking pin154. The tip assembly60rotates with the entire tube assembly46by virtue of the fixed connection between the tip assembly60and the tube56of the tube assembly46. Therefore, if a different radial orientation of the tip assembly60is desired, relative to the body assembly42and handles48,50, the tube assembly46is rotated and locked into the preferred orientation via the locking pin154. When the plunger166is released, the force imparted to the lock150from the locking spring164causes the locking pin154to automatically engage the locking groove62.

To improve the ability of the surgeon to grip the body134to use the release plunger166to perform a one handed release of the tube assembly46, a cap173is formed on the body134, on the plunger axis AA opposite the head170of the release plunger166, as shown inFIGS. 26 and 27. The cap173covers the end172of the release plunger166such that when surgeon grasps the body134, a finger can rest on the cap173and another finger can rest on the head170. This allows the surgeon to squeeze the head170along the plunger axis AA toward the cap173to release the locking pin154with a single hand.

An grabbing assembly175includes a collet176and a stem178. The collet176includes a collet housing180and jaws181extending from the collet housing180. The collet housing180is generally circular and defines a stem opening182for receiving a portion of the stem178. The stem opening182extends through the collet housing180and into the jaws. The jaws181include two or more fingers184that extend from the collet housing180to be able to grab the cable end retainer86. In a “relaxed” position, the fingers184diverge from the collet housing180, as shown inFIGS. 29 and 31. When the fingers184are disposed inside of the collet chamber142, the fingers184are “restricted” by the collet chamber142such that they extend from the collet housing180in a generally parallel relationship130, as shown inFIGS. 28 and 30, and they grab and retain the cable end retainer86that is attached to the cable70. When a tube assembly46is inserted into the body134and the fingers184are inside of the collet chamber142, the cable end retainer86engages and retains the cable end76and is retained within the collet176. The stem178includes a stem shaft190and a pair of stem arms192, extending from the stem178in a spaced and parallel relationship. The stem arms192each define a stem hole194, aligned along the same axis.

When the grabbing assembly175is disposed in the collet chamber142, a resistance spring195surrounds the stem shaft190, inside of the collet chamber142. The resistance spring195is positioned between the collect housing180and the threaded nut197. Accordingly, as the grabbing assembly175is pulled rearward in the collet chamber142, the resistance spring195is compressed between the collect housing180and the threaded nut197. When the grabbing assembly175is released, the resistance spring195forces the grabbing assembly175to slide forward in the collet chamber142and open handles48,50.

A top link196and a bottom link198are used to interconnect the stem178and the upper and the lower handles48,50. Each link defines a link hole204and a stem hole194at opposite ends thereof. Each handle48,50defines a link hole204. The top and the bottom links198are inserted between the arms of the stem178and the stem holes194of the top and the bottom links198are aligned with the stem holes194of the stem arms192. A stem screw208is inserted through all of the stem holes194to retain the links196,198to the stem arms192, while allowing the links196,198to pivot with respect to the handles48,50. The link hole204of the top link196is aligned with the link hole204of the upper handle48. A link screw200is inserted through the link holes204, while allowing the top link196to pivot with respect to the upper handle48. The link hole204of the bottom link198is aligned with the link hole204of the lower handle50. A link screw200is inserted through the link holes204while allowing the bottom link198to pivot with respect to the lower handle50.

Referring toFIG. 34, loading and unloading a tube assembly46into the body assembly42is facilitated by spreading the upper and lower handles48,50far apart, i.e., pulled apart from one another, such that the links196,198cause the stem178to push the fingers184and cable end retainer186all the way into the body chamber140, as shown inFIG. 34. When the fingers184and the cable end retainer186of the collet176enter the body chamber140, the fingers184and cable end retainer186are no longer restricted by the collet chamber142and no longer engage the cable end76, if a tube assembly46is already loaded into the body assembly42. If the plunger166is also depressed and the locking pin154is no longer engaging the locking groove62, the tube assembly46may be removed from the body assembly42.

Referring toFIG. 33, as the upper and the lower handles48,50are closed, i.e., pulled toward one another, the links196,198cause the stem178to pull the fingers184and the cable end retainer86into the collet chamber142. The slope188on each of the fingers184rides along a step206located between the chamber140of the body and the collet chamber142. Because the diameter of the collet chamber142is smaller than the diameter of the chamber140of the body134, the slope188and the step206cooperate to close the fingers184onto the cable end retainer86. As the cable end retainer186is grabbed, it pulls the cable end76if a tube assembly46is inserted into the body assembly42.

Similarly, movement of the handles48,50relative to one another moves the blade90relative to the tip92in the tip assembly60. However, the handles48,50are not spread as far apart as when loading and unloading a tube assembly46from the body assembly42. Therefore, when the handles48,50are moved apart, as shown inFIG. 33, the links196,198cause the stem178to push the fingers184forward in the collet chamber142which, in turn, pushes the cable70forward through the tube56. As the cable70moves forward in the tube56, the cable end76and the blade90, at the cable pin holes83, slide forward in the tip assembly60. However, because the blade90remains only pivotally connected to the tip92via the tip pinhole82, the blade90rotates out of the hollow interior59of the tip92. Likewise, as the handles48,50are moved together, as shown inFIG. 32, the links196,198cause the stem178to pull the fingers184rearward in the tube56. As the cable70moves rearward in the tube56, the cable end76and the blade90, at the cable pinhole83, slide rearward in the tip assembly60. Accordingly, the blade90rotates into the hollow interior59of the tip92by pivoting about the tip pin133.

There are four stops within the forceps40which operate to limit the rotation of the blade90with respect to the tip92. First, as the handles48,50are closed, stops144on the body assembly42limit the travel of the handles48,50which limits the amount the blade90can enter the tip92of the tip assembly60. Second, the hip130on the rear curved surface128of the tip92provides a stop for the shoulder80of the cable70to limit the travel of the blade90and prevent the cutting region102of the blade90from extending through the tip92. Third, the front sloping edge78of the cable70cooperates with the first blade stop107to limit the travel of the blade90and limit the closing of the blade90with respect to the tip92. The fourth included mechanical stop is when blade stop109on the blade90contacts the top edge79on the cable70, as shown inFIG. 3, to limit the opening of the blade90with respect to the tip92to and angle CC usually no greater than 50 to 60 degrees, as shown inFIG. 3.

The shear pin88that retains the cable end76to the cable retainer86has a lower shear force than the tip pin133and the cable pin132. This means that if too great of force is exerted on the entire tube assembly46by virtue of moving the handles48,50, the shear pin88will break and the tip pin133and the cable pin132will not. This is important because the shear pin88is inside of the chamber140of the body and will not result in any loose parts accidentally entering the patient during the surgical procedure should the shear pin88break.

Referring toFIGS. 35 and 36, an alternative embodiment of the forceps240is shown. The forceps240are adapted to include an electrode assembly241, such as an aspirating ablating electrode assembly241, instead of the tube assembly46. The electrode assembly241includes a hollow tube256extending between an adapter258and an ablating end243. The adapter258encircles the tube256and defines a plurality of locking holes262and a groove263encircling the adapter258. A knob259extends from the adapter258for being gripped to rotate the electrode assembly241. The tube256and the adapter258each define a hollow interior270. A flushing port266is formed in and extends from the adapter258. The flushing port266defines a duct268into the hollow interior270of the adapter258for flushing the tube assembly246, via pumping or sucking fluids from the area of the body the operation is occurring. At least one tube256extends between the ablating end243and the locking holes262and groove263of the adapter258. When there is only one electrode245, the electrode assembly241is a monopolar electrode assembly241, as shown inFIG. 35. With the monopolar electrode assembly241, a positive source of electricity is passed through the electrode245and a negative source of energy, or ground, is attached to a ground pad such that the energy passes through the patient and into the ground pad. This electricity can be used for cutting, sealing, ablation and coagulation.

However, when there are two sources of electricity energizing to tip243, the electrode assembly241is a bipolar electrode assembly241, as shown inFIG. 36. In the bipolar electrode assembly241, power plug248takes the place of the spring cap162where the power plug248defines an internal shaft which provides a passage for the leads249to pass through the power plug248and into the body134to contact the adaptor58in two well separated spots. The leads249then extend to the electrode tip243where each lead charges individually insulated portions of the tip243. Arcing between the insulated zones is used for bipolar cutting, sealing, ablation and coagulation. Additionally, to cool the electrodes245, saline is passed through the flushing port266, through the hollow tube256, and out through or into the ablating end243. The saline is required to provide efficient ablation of the tissue and to prevent the electrodes245from melting. Although saline is disclosed as a coolant, the invention is not limited to the use of saline as any other type of coolant may also be used so long as it provides sufficient cooling of the electrodes245and ablation of the tissue.

As shown inFIGS. 37 and 38, when the electrode assembly241is used, articulation of handles48,50is not required. Therefore, the electrode assembly241also includes an extension251which extends from the adapter258and simulates the cable end86. To assemble the electrode assembly241to the body assembly42, the handles48,50are spread apart and in the open position. When the handles48,50are in the open position, the links196,198cause the stem178to push the fingers184forward in the collet chamber142, as shown inFIG. 37. Then, the column251is inserted between the fingers184and the handles48,50are closed. Closing the handles48,50causes the stem178to pull the fingers184rearward in the collet chamber142and around the extension251, as shown inFIG. 38. This, in effect, locks the electrode assembly241to the body assembly42and also keeps the handles48,50immobile and enclosed so that the surgeon can grasp the handles48,50to maneuver the electrode assembly241during surgery. To further insulate the surgeon from the energy going through the electrode assembly241, the stem178and body134are formed from plastic or some other insulating type of material. However, the handles48,50may be made from any type of metal or other type of non-insulating material because they are insulated from the electrode assembly241by the body made of or constructed by nonconductive material.

Alternatively, referring toFIG. 39, when the electrode assembly241is used the electrode assembly241also includes a trunk253which extends from the adapter258at a diameter at least slightly less than the diameter of the collet chamber142. To assemble the electrode assembly241to the body assembly42, the handles48,50are spread apart and in the open position. When the handles48,50are in the open position, the links196,198cause the stem178to push the fingers184forward in the collet chamber142. As the electrode assembly241is inserted into the body assembly42, the trunk253pushes against the fingers184forcing the fingers184into the collet chamber142as the trunk253also enters the collet chamber142. This also causes the handles48,50to close. The electrode assembly241is locked into the body assembly42by virtue of the locking pin154engaging the locking groove262of the electrode assembly241.

Many modifications and variations of the present invention are possible in light of the above teachings. In addition, the reference numerals in the claims are merely for convenience and are not to be read in any way as limiting.