Ultrasonic surgical instrument

An ultrasonic surgical instrument for boring a hole in a femur, including: an ultrasonic vibrator capable of generating ultrasonic vibration; a probe including a proximal end portion connected with the ultrasonic vibrator and a distal end treatment portion capable of boring a bone hole in the femur, and transmitting the ultrasonic vibration; and a cylindrical member covering the proximal end portion of the probe and not covering an exposed portion including the distal end treatment portion. The distal end treatment portion includes a columnar portion having a cross-sectional area that is larger than that of a remainder of the exposed portion of the probe.

BACKGROUND

The present disclosure relates to an ultrasonic surgical instrument to treat a biotissue, such as bones.

For example, US20100167235A1 discloses a surgical tool to bore a hole in the bone. The surgical tool functions by ultrasonic waves, and the chip of the tool includes a plurality of cutting elements defining the outline of the hole formed in the bone. Removal (cutting) of the bone is performed with minute vibration by ultrasonic vibration. SUMMARY When the bone or the like in the deep part in the human body is treated using a surgical instrument to treat bones, there are cases where the surgical instrument interferes with the tissue or the bone or the like positioned on the surface layer side of the human body. This generates needs for ultrasonic surgical instruments preventing such interferences.

An ultrasonic surgical instrument to bore a bone hole in the femur according to the embodiment comprises: an ultrasonic vibrator generating ultrasonic vibration; a probe including a proximal end portion connected with the ultrasonic vibrator and a distal end treatment portion boring a bone hole in the femur, and transmitting the ultrasonic vibration; and a cylindrical member covering the probe, the cylindrical member covering the proximal end portion of the probe and including a distal end portion positioned on the proximal end portion side of the distal end treatment portion of the probe at a distance of 25 to 80 mm from the distal end treatment portion.

DETAILED DESCRIPTION

An exemplary embodiment will be explained hereinafter with reference toFIG. 1toFIG. 8. A treatment system according to the present embodiment is suitably used for, for example, an anterior cruciate ligament (ACL) reconstructive operation of the knee joint and other operations.

When a knee joint100is treated, for example, a treatment system10illustrated inFIG. 1is used. The treatment system10includes an arthroscope device12, a treatment device14, and a perfusion device16.

As illustrated inFIG. 1, the arthroscope device12includes an arthroscope21observing the inside of the knee joint100, that is, the inside of an articular cavity136, an arthroscope controller22performing image processing on the basis of a subject image imaged with the arthroscope21, and a monitor23displaying an image generated by image processing performed with the arthroscope controller22. The arthroscope21is inserted into the articular cavity136of the knee joint100with a first portal102serving as a skin incision portion causing the inside of the knee joint100and the outside of the skin of the patient to communicate with each other. The position of the first portal102is not uniform, but can be properly determined according to the state of the patient. A cannula (not illustrated) is disposed on the first portal102, and the arthroscope21may preferably be inserted into the articular cavity136of the knee joint100through the cannula. The arthroscope21and a treatment tool24of the treatment device14described later are illustrated in a state of being opposed to each other inFIG. 1, but they are arranged with a proper positional relation according to the position of the treatment target or the like.

The treatment device14includes a treatment unit25, a treatment unit controller26, and a switch27. The switch27is illustrated as a hand switch inFIG. 1, but may be a foot switch. The treatment device14is an example of the ultrasonic surgical instrument.

The processing unit controller26supplies proper energy (electric power) to a vibrator unit28(described later) of the treatment unit25in accordance with an operation of the switch27, to transmit ultrasonic vibration to a distal end treatment portion32of a probe31of the treatment unit25described later. The probe31is inserted into the articular cavity136of the knee joint100with a second portal104serving as a skin incision portion causing the inside of the knee joint100and the outside of the skin of the patient to communicate with each other. The position of the second portal104is not uniform, but can be properly determined according to the state of the patient. A cannula (not illustrated) is disposed on the second portal104, and the probe31may preferably be inserted into the articular cavity136of the knee joint100through the cannula. The switch27maintains a state in which a vibrator (ultrasonic vibrator) described later is driven in the state in which the switch27is pressed, and the state in which the vibrator is driven is released when the switch27in the pressed state is released.

This example illustrates the case where one switch27is provided, but a plurality of switches27may be provided. The amplitude of the vibrator can be properly set with the treatment unit controller26. For this reason, by the operation of the switch27, the amplitude may be set different, although the frequency of the ultrasonic vibration output from the vibrator unit28described later is the same. Accordingly, the switch27may preferably be capable of switching the amplitude of the vibrator unit28between a plurality of states, for example, a large amplitude and a small amplitude.

The perfusion device16includes a liquid source33containing a perfusion liquid, such as a physiological saline solution, a perfusion pump unit34, a liquid feed tube35connected at one end with the liquid source33, a liquid discharge tube36, and a suction bottle37connected with one end of the liquid discharge tube36. The suction bottle37is connected with a suction source attached to the wall of the operating room. The perfusion pump unit34is capable of feeding the perfusion liquid from the liquid source33with a liquid feed pump38. The perfusion pump unit34is also capable of switching suction and stop suction of the perfusion liquid in the articular cavity136of the knee joint100with respect to the suction bottle37by opening and closing a pinch valve41serving as a liquid discharge valve.

The other end of the liquid feed tube35serving as a liquid feed pipe line is connected with the arthroscope21. For this reason, the perfusion liquid can be fed into the articular cavity136of the joint100through the arthroscope21. The other end of the liquid discharge tube36serving as a liquid discharge pipe line is connected with the arthroscope21. This structure enables discharge of the perfusion liquid from the inside of the articular cavity136of the joint100through the arthroscope21. As a matter of course, the other end of the liquid discharge tube36may be connected with the treatment tool24to enable discharge of the perfusion liquid from the inside of the articular cavity136. The perfusion liquid may be fed and discharged through another portal.

As illustrated inFIG. 2, the treatment unit25includes the treatment tool24and the vibrator unit28. It is preferable that the vibrator unit28is attachable to and detachable from the treatment tool24, but the treatment tool24may be united with the vibrator unit28. The vibrator unit28includes a vibrator case42, a horn member43, a vibrator44(ultrasonic vibrator, piezoelectric element) formed of a bolt-clamped Langevin-type transducer, and a connecting portion45provided at the distal end of the horn member43and connected with a proximal end portion31A of the probe31described later. The connecting unit45preferably projects to the distal end side of the vibrator case42along a central axis C of the vibrator unit28. A cable46extends from the proximal end of the vibrator case42of the vibrator unit28. One end of the cable46is connected with the vibrator unit28, and the other end of the cable46is connected with the treatment unit controller26. The horn member43and the vibrator44form a united vibrator. In the present embodiment, the vibrator is set to generate ultrasonic vibration at a certain frequency (for example, 47 kHz) in a specific frequency range (for example, 40 to 50 kHz).

The vibrator case42supports a supported portion47of the vibrator. Because the vibrator unit28is publicly known, a detailed explanation thereof is omitted. In the state in which the vibrator44is caused to generate vibration, the connecting portion45serves as an antinode of ultrasonic vibration. Although not illustrated inFIG. 2, the switch27is preferably disposed in the vibrator case42of the vibrator unit28or a housing48of the treatment tool24described later.

The treatment tool24includes the housing48(handle), a cylindrical member51(outer cylinder, sheath) extended from the housing48along the central axis C, and the probe31(ultrasonic probe) inserted through the inside of the cylindrical member51. In the treatment tool24, the side on which the housing48is positioned with respect to the cylindrical member51is referred to as proximal end side (arrow C1side), and the side opposite to the proximal end side is referred to as distal end side (arrow C2side). The cylindrical member51is attached to the housing48from the distal end C2side. The cylindrical member51covers a part extending from the proximal end side31A of the probe31to a substantially middle portion of the probe31with respect to the direction of the central axis C. A watertight rubber lining52is provided between the internal circumferential surface of the cylindrical member51and the external circumferential surface of the probe31. The rubber lining52prevents the liquid from entering the inside of the cylindrical member51. The rubber lining52is provided to correspond to, for example, the node position of ultrasonic vibration, in the state in which the probe31is vibrated with ultrasonic waves at a certain frequency (for example, 47 kHz) in a specific frequency range (for example, 40 to 50 kHz).

The housing48of the treatment tool24is formed of a material having electrical insulation property. The vibrator case42of the vibrator unit28is detachably connected with the housing48. The housing48of the treatment tool24may be preferably united with the vibrator case42of the vibrator unit28.

A rotary knob (not illustrated) serving as a rotary operating member may be attached to the housing48of the treatment tool24. The rotary knob is rotatable with respect to the housing48around the central axis of the cylindrical member51. The housing48, the cylindrical member51, the distal end treatment portion32described later, and a probe main member unit54of the vibrator unit28rotate together with respect to the housing48around the central axis C of the probe main member unit54by rotation of the rotary knob.

The external circumferential surfaces of the housing48and the cylindrical member51of the treatment tool24have insulating property, but may have no insulating property. The probe31is formed of a material capable of transmitting ultrasonic vibration, such as a metal material. An exemplary metal material includes a titanium alloy material. The whole length of the probe31is, for example, preferably substantially an integral multiple of a half wavelength based on the resonant frequency of the vibrator44. The whole length of the probe31is not limited to an integral multiple of a half wavelength based on the resonant frequency of the vibrator44, but properly regulated according to the material and/or the amplitude extension ratio or the like. For this reason, the whole length of the probe31may be substantially an integral multiple of a half wavelength based on the resonant frequency of the vibrator44.

As illustrated inFIG. 2andFIG. 3, the probe31includes the probe main member unit54, the proximal end portion31A provided on the probe main member unit54and connected with the ultrasonic vibrator44, and the distal end treatment portion32provided on the distal end C2side of the probe main member unit54, and capable of boring a hole in the bone serving as the treatment target by ultrasonic vibration. The probe main member unit54has, for example, a substantially cylindrical shape. The probe main member unit54may has an oval cross section, as illustrated inFIG. 10. The probe main member unit54includes a portion exposed from the cylindrical member51and a portion contained in the cylindrical member51. As illustrated inFIG. 3, the distal end treatment portion32and a portion exposed from the cylindrical member51in the probe main member unit54form an exposed portion55.

In the present embodiment, a distal end portion51A of the cylindrical member51is positioned on the proximal end portion31A side of the distal end treatment portion32(cutting portion56) of the probe31at a distance of 25 to 80 mm from the distal end treatment portion32. In other words, the length of the exposed portion55in the central axis C direction is 25 to 80 mm. More preferably, the length of the exposed portion55in the central axis C direction is 40 to 80 mm (the distal end portion51A of the cylindrical member51is positioned on the proximal end portion31A side of the distal end treatment portion32(cutting portion56) of the probe31at a distance of 40 to 80 mm therefrom). More preferably, the length of the exposed portion55in the central axis C direction is 50 to 80 mm (the distal end portion51A of the cylindrical member51is positioned on the proximal end portion31A side of the distal end treatment portion32(cutting portion56) of the probe31at a distance of 50 to 80 mm therefrom).

Ultrasonic vibration generated with the ultrasonic vibrator44is transmitted to the probe main member unit54through the connecting portion45of the vibrator. Ultrasonic vibration generated with the vibrator44is transmitted to the distal end treatment portion32through the connecting portion45and the probe main member unit54.

The distal end treatment portion32includes the cutting portion56(cutting blade) at a distal end thereof. In this example, the cutting portion56is formed as a square pyramid illustrated inFIG. 2andFIG. 3. The projection shape of the cutting portion56when the proximal end C1side is viewed from the distal end C2side along the central axis C (longitudinal axis) of the distal end treatment portion32has a substantially square shape illustrated with a solid line inFIG. 9, or a polygonal shape. The polygon may be an equilateral polygon. The cutting portion56has a small contact area with the bone in the initial state of cutting the bone. This structure enables concentration of pressure (stress) in the distal end of the cutting portion56, and enables start of cutting with relatively small force.

From the viewpoint of reducing friction between the femur112and the distal end treatment portion32and the viewpoint of discharging the excised piece generated from the femur112, the maximum external shape portion of the distal end treatment portion32in the direction (ultrasonic vibration direction) along the central axis C preferably has a short length. For this reason, a columnar portion50(seeFIG. 2) having a square cross-sectional shape in the distal end treatment portion32is preferably configured to have a cross section gradually decreasing along the central axis C, not the same shape or the same cross section.

It is preferable that the probe31is moved straight along the central axis C, to form a recessed hole57straight along the central axis C with the columnar portion50of the distal end treatment portion32. For this reason, to prevent staggering of the distal end treatment portion32and form the recessed hole57straight, the columnar portion50is required to have a certain length in the central axis C direction.

In addition, the distal end treatment portion32cuts the femur112while ultrasonic vibration of a proper amplitude is transmitted to the probe31. For this reason, the columnar portion50of the distal end treatment portion32is required to have proper strength. In the case where the cross section of the columnar portion50gradually decreases from the distal end toward the proximal end side of the distal end treatment portion32, a certain cross-section decrease ratio or the like may cause difficulty in forming the distal end treatment portion32with strength necessary for cutting the femur112with the distal end treatment portion32, while ultrasonic vibration of proper amplitude to the probe31.

The columnar portion50(seeFIG. 2) of the distal end treatment portion32of the probe31according to the present embodiment includes a region forming the maximum external shape portion with a certain length along the central axis C. In the present embodiment, the cross section of a surface of the columnar portion50orthogonal to the central axis C is the same or substantially the same in the central axis C direction. As described above, because the distal end treatment portion32is provided with the columnar portion50, it is possible to form the straight recessed hole57in the same shape as the maximum external shape portion of the columnar portion50in cutting of the femur112, while the strength of the distal end treatment portion32is maintained when the probe31is moved straight along the central axis C toward the distal end side.

When the ACL reconstructive operation is performed using a STG tendon described later, the external shape of the cross section orthogonal to the longitudinal axis of the grafted tendon is formed in a substantially rectangular shape of a size of approximately 4 mm×5 mm. For this reason, as an example, when the projection shape of the distal end treatment portion32is a substantially rectangular shape, the external shape of the cross section orthogonal to the central axis C preferably has a size of approximately 4 mm×5 mm.

As schematically illustrated inFIG. 4, in the state in which the probe31is vibrated with ultrasonic waves at, for example, a certain frequency (for example, 47 kHz) in a specific frequency range (for example, 40 to 50 kHz) an antinode position, a node position, an antinode position, and a node position . . . alternately appear from the distal end (cutting portion56) of the distal end treatment portion32to the proximal end portion31A of the probe31. In addition, a node of ultrasonic vibration appears in the exposed portion55of the probe31. Ultrasonic vibration transmitted to the probe31is longitudinal vibration along the central axis C direction of the probe31. The sine curve illustrated inFIG. 4schematically illustrates amplitude in each point on the probe31. The portion at which the amplitude is maximum is an antinode position, and the portion at which the amplitude is zero is a node position. The wavelength A can be calculated from the following expression.
λ=C/f=√E/ρ/f[Numerical Expression 1]

In the expression described above, C is transmission speed in the medium, f is the frequency, E is Young's modulus, and p is density. Each of E and p is material physical property, and the internode distance (λ/2) depends on the material and the frequency. The length from the distal end (distal end of the cutting portion56) of the probe31to the node position is approximately λ/4 fromFIG. 4, and may be finely regulated in consideration of the strength of the distal end treatment portion32, the stability of vibration, and the accessibility to the treatment target region.

In the present embodiment, as illustrated inFIG. 3, in the state where the probe31is vibrated (resonated) by ultrasonic waves at a certain frequency (for example, 47 kHz) in a specific frequency range (for example, 40 to 50 kHz), the node position appears in at least two positions, that is, the middle position in the exposed portion55and a position covered with the cylindrical member51. For example, in the case of using medical titanium alloy as the material of the probe31, the distance (λ/2) between the node positions of ultrasonic vibration in the ultrasonic-vibrated state is approximately 47 mm (in the case at 50 kHz) to 53 mm (in the case at 40 kHz) when it is calculated with the expression of Numerical Expression 1 described above.

The probe main member unit54is preferably formed in a straight shape. The distal end treatment portion32is preferably extended straight from the distal end of the probe main member unit54toward the distal end side, but may be properly bent in consideration of the visibility of the distal end treatment portion32with the arthroscope21. For this reason, the longitudinal axis of the distal end treatment portion32may agree with the central axis C of the probe main member unit54, or may be different therefrom.

The following is an explanation of the function of the treatment system10according to the present embodiment with reference toFIG. 5toFIG. 7, with an example of the case of performing an anterior cruciate ligament (ACL) reconstructive operation of the knee joint. The explanation hereinafter mainly illustrates the case of forming the recessed hole57in the bone112using the treatment unit.

The operating method can be divided into, for example, two, according to the material of the grafted tendon of the ligament to be reconstructed. One is a method of using a semitendinosus tendon or a gracilis tendon inside the knee as the grafted tendon (STG tendon). The other is a method of using a patellar tendon as the grafted tendon (BTB tendon). The following example illustrates the case of using a STG tendon as an example to form the bone hole by an inside-out method going from the inside of the articular cavity136toward the outside of the femur112.

In the method of using a STG tendon as the grafted tendon, a semitendinosus tendon or a gracilis tendon located inside the knee is extracted as the grafted tendon (STG tendon) from the patient's body. The length of the tendon at this operation is approximately 250 mm to 300 mm. The extracted tendon is bent a plurality of times, such as four to six times, to form a grafted tendon having a rectangular cross section orthogonal to the longitudinal axis and provided with a substantially rectangular external shape.

By contrast, a prepared hole of a small diameter is formed in a predetermined position of the femur112using a drill or the like to pierce the femur112, and a prepared hole of a small diameter is formed in a predetermined position a tibia114using a drill or the like to pierce the tibia114. The prepared hole may be performed in a state in which a perfusion liquid, such as a physiological saline solution, is circulated in the articular cavity136.

As illustrated inFIG. 6, a recessed hole57(bone hole) is formed from the inside of the articular cavity136using the treatment system10according to the present embodiment such that the recessed hole57is concentric with the center of the prepared hole of the femur112(in the drawings attached to the present specification, illustration of the prepared hole is omitted). No prepared hole may be provided in some operating methods. The diameter of the recessed hole57is larger than the diameter of the prepared hole. Formation of the recessed hole57is also performed in the state in which a perfusion liquid, such as a physiological saline solution, is circulated in the articular cavity136. In the case of using a STG tendon, the recessed hole57has a rectangular shape, for example, with shorter sides of 4 mm, longer sides of 5 mm, and a depth of approximately 15 mm.

When the switch27is operated, energy is supplied from the treatment unit controller26to the vibrator44of the vibration member fixed on the proximal end portion31A of the probe31, and ultrasonic vibration is generated in the vibrator44. In this manner, ultrasonic vibration is transmitted to the ultrasonic probe31through the vibration member (horn member43). The vibration is transmitted from the proximal end C1side to the distal end C2side of the probe31.

Because the distal end treatment portion32serves as an antinode of vibration, the distal end treatment portion32is displaced along the central axis C at speed (for example, several thousand m/s). For this reason, when the distal end treatment portion32(cutting portion56) in the state in which vibration is transmitted is pressed against the bone112along the central axis C toward the distal end C2side, the part of the bone112which the distal end treatment portion32contacts is crushed. Accordingly, as illustrated inFIG. 6andFIG. 7, a recessed hole57is formed in the bone112along the central axis C of the distal end treatment portion32of the probe31. In a conventional ultrasonic surgical tool, as illustrated inFIG. 5, when the recessed hole57is formed, the cylindrical member51interferes with the femur medial condyle112A at a position illustrated with A inFIG. 5, and the interference may hinder the work of forming the recessed hole57.

As illustrated inFIG. 6, a distance A from the second portal104to the position at which the recessed hole57is formed on the femur112is generally approximately 70 mm, although it differs between individuals. A distance B from the second portal104to a femur medial condyle112A is generally approximately 40 mm, although it differs between individuals. A distance C from the femur medial condyle112A to the position at which the recessed hole57is formed is generally approximately 30 mm, although it differs between individuals. When the patient is small or a child, each of the sizes described above may be smaller than the values described above.

In the present embodiment, as illustrated inFIG. 6andFIG. 7, the cylindrical member51retreats toward the proximal end C1side, and the exposed portion55is sufficiently long. Specifically, the length of the exposed portion55in the central axis C direction is 25 to 80 mm, preferably 40 to 80 mm, more preferably 50 to 80 mm. For this reason, when the length of the exposed portion55is, for example, 40 to 80 mm or 50 to 80 mm, a space of at least approximately 10 mm (when the length of the exposed portion55is 40 to 80 mm) to 20 mm (when the length of the exposed portion55is 50 to 80 mm) is secured between the femur medial condyle112A and the distal end portion51A of the cylindrical member51, even when the distal end treatment portion32reaches the position at which the recessed hole57is formed in the femur112. By contrast, even when the length of the exposed portion55is 25 to 80 mm, when the patient is small or a child, a space is secured between the femur medial condyle112A and the distal end portion51A of the cylindrical member51, even when the distal end treatment portion32reaches the position at which the recessed hole57is formed in the femur112.

For this reason, the cylindrical member51does not interfere with the femur medial condyle112A in the form of the probe31. The treatment device14of the present embodiment enables treatment of removal and cutting even for peripheral tissues (such as the cartilage) around the bones112and114. This structure enables the operator to perform efficient treatment without changing the treatment devices14according to the tissue serving as the treatment target. Debris generated when the bone112and the cartilage are crushed are properly discharged to the probe main member unit54side, and discharged to the outside of the body by flow of the perfusion liquid. When the depth of the recessed hole57reaches a predetermined value, preparation of the recessed hole57is finished.

By contrast, string is fixed at one end of the grafted tendon. In an example of the anterior cruciate ligament reconstructive operation, a string is inserted through the prepared hole on the femur112side, and fixed on the external circumferential portion of the femur112around the outlet of the prepared hole with a suspensory fixing tool. In this operation, part of the grafted tendon is inserted into the recessed hole57, and fixed in close contact with the internal circumferential surface of the recessed hole57. The other end opposite to one end of the grafted tendon is inserted through the prepared hole formed in the tibia114, and fixed on the external circumferential surface of the tibia114around the outlet of the prepared hole with a tendon-fixing staple. In this manner, the anterior cruciate ligament reconstructive operation is finished.

According to the present embodiment, the ultrasonic surgical instrument is an ultrasonic surgical instrument to form a bone hole in the femur112, comprising an ultrasonic vibrator generating ultrasonic vibration, the probe31including the proximal end portion31A connected with the ultrasonic vibrator and the distal end treatment portion32forming a bone hole in the femur112and transmitting the ultrasonic vibration, and the cylindrical member51covering the probe31. The cylindrical member51covers the proximal end portion31A of the probe31, and includes the distal end portion51A disposed on the proximal end31A side of the distal end treatment portion32of the probe31at a distance of 25 to 80 mm from the distal end treatment portion32.

When the probe31is vibrated with ultrasonic waves at a certain frequency in a specific frequency range, at least one node position of the ultrasonic vibration appears in the exposed portion55of the probe31located in a position falling out of the cylindrical member51.

Generally, the diameter of the cylindrical member51is larger than the diameter of the probe31. For this reason, a conventional ultrasonic surgical tool has the possibility that the cylindrical member51interferes with the femur medial condyle112A when a bone hole is formed in the femur112and the interference hinders the operation. With the structure described above, the exposed portion55of the probe31is provided with sufficient length such that the probe31projects at a distance of 25 to 80 mm from the distal end portion51A of the cylindrical member51or a node position appears in the exposed portion55of the probe31(that is, the length from the distal end of the probe31to the distal end of the cylindrical member51is at least λ/4 or more). This structure markedly reduces the possibility of interference of the cylindrical member51with the femur medial condyle112A when the bone hole is formed in the femur112. This structure enables the operator to smoothly perform treatment to form a bone hole in the femur112with the sufficiently long probe31.

The distal end portion51A of the cylindrical member51is positioned on the proximal end portion31A side of the distal end treatment portion32at a distance of 40 to 80 mm from the distal end treatment portion32. This structure secures, for the exposed portion55of the probe31, a length sufficiently longer than 30 mm being an average length between the position at which the bone hole is formed in the femur112and the femur medial condyle112A. This structure markedly reduces the possibility of interference of the cylindrical member51with the femur medial condyle112A when the bone hole is formed in the femur112.

The distal end portion51A of the cylindrical member51is positioned on the proximal end portion31A side of the distal end treatment portion32at a distance of 50 to 80 mm from the distal end treatment portion32. This structure secures, for the exposed portion55of the probe31, a length sufficiently longer than 30 mm being an average length between the position at which the bone hole is formed in the femur112and the femur medial condyle112A. This structure markedly reduces the possibility of interference of the cylindrical member51with the femur medial condyle112A when the bone hole is formed in the femur112.

The following is an explanation of another exemplary embodiment. In the following discussion, aspects of this embodiment that are different from the embodiment described above will be mainly explained, and an explanation or illustration of aspects that are the same as those of the embodiment described above is omitted.

In the embodiment illustrated inFIG. 8, the vibrator unit28is different in output from the vibrator unit28according to the embodiment described above. Specifically, the vibrator44(bolt-clamped Langevin-type transducer) of the vibrator unit28according to the present embodiment is capable of vibrating the distal end treatment portion32of the probe31by ultrasonic waves at 20 to 25 kHz in a state where the vibrator44is connected with the probe31. When the probe31is vibrated with ultrasonic waves as described above at a frequency lower than that of the above embodiment, the node position of ultrasonic vibration appears inside the cylindrical portion51. For example, when a medical titanium alloy is used as the material of the probe31, a distance (λ/2) between the node positions of ultrasonic vibration in the ultrasonic-vibrated state is approximately 90 mm (in the case of 20 kHz) to 120 mm (in the case of 25 kHz) when the distance is calculated with the expression of Numerical Expression 1. Ultrasonic vibration of such a frequency also enables smooth formation of the recessed hole57in the femur112.

The following is an explanation of another exemplary embodiment of the treatment system with reference toFIGS. 9 to 12. The following explanation mainly illustrates aspects different from the above embodiments, and an explanation or illustration of aspects that are the same as those in the above embodiments is omitted.

As illustrated inFIG. 9andFIG. 11, a treatment tool24of a treatment system10includes a housing48, a cylindrical member51extended from the housing48along a central axis C, a probe31inserted through the inside of the cylindrical member51, a protective member61covering part of the probe31, and a second protective member71disposed in the second portal104serving as the skin incision portion. The protective member61is formed of, for example, a synthetic resin material in a cylindrical shape. The protective member61is provided on and in close contact with the external circumferential surface of the probe31. The protective member61enables covering of the probe31from the proximal end portion31A side to a position close to the distal end treatment portion32of the probe31. A space E of several millimeters is provided between the distal end of the protective member61and the distal end treatment portion32. As illustrated inFIG. 11, a space62is provided between the protective member61and the second protective member71.

As illustrated inFIG. 9, the distal end treatment portion32and a part of a probe main member unit54exposed from the cylindrical member51form an exposed portion55. The exposed portion55of the probe31is formed longer than the exposed portion55of the probe31of the above embodiments shown in, for example,FIGS. 3, 6, 7, and 8. In the present embodiment, most of the part (shaft portion) of the exposed portion55corresponding to the probe main member unit54is covered with the protective member61, instead of being covered with the cylindrical member51. The length of the exposed portion55in the central axis C direction may be, for example, 25 to 80 mm. In addition, in the present embodiment, the exposed portion55preferably has a form suitable for forming a recessed hole deeper than the recessed hole57formed in the above embodiments or a through hole piercing through the femur112. For example, the length of the exposed portion55in the central axis C direction is preferably 60 to 80 mm.

The protective member61is preferably formed of a resin material (heat shrinkable tube) having heat shrinkability. When such probe31and protective member61are manufactured, in a state in which the heat-shrinkable protective member61is disposed around the probe31, heat treatment is performed on the protective member61, to bring the protective member61in close contact with the external circumferential surface of the probe31without a gap. The diameter of the protective member61is smaller than the diameter of the cylindrical member51and, for example, ½ to ⅓ as large as the diameter of the cylindrical member51. As is clear fromFIG. 10, the diameter (shorter diameter) of the protective member61is smaller than the vertical and horizontal lengths of the distal end treatment portion32. For this reason, the existence of the protective member61does not hinder the work in formation of the recessed hole57.

As illustrated inFIG. 11, in the treatment system100of the present embodiment, the second protective member71formed of a trocar or the like is preferably disposed in the second portal104formed of the skin incision portion. This structure prevents the protective member61formed of a heat-shrinkable resin material from directly contacting the skin incision portion.

The following is a function of the treatment system according to the present embodiment with reference toFIG. 11andFIG. 12, with the case of performing an anterior cruciate ligament reconstructive operation in the knee joint100as an example. The explanation mainly illustrates the case of forming a recessed hole57in the bone112using the treatment unit25.

In the same manner as the above embodiment, a grafted tendon (STG tendon, BTB tendon) is extracted by a publicly-known method. In parallel with this, a prepared hole of a small diameter is formed in a predetermined position of the femur112using a drill or the like to pierce the femur112, and a prepared hole of a small diameter is formed in a predetermined position of the tibia114using a drill or the like to pierce the tibia114.

A recessed hole57is formed from the inside of the articular cavity136using the treatment system10according to the present embodiment such that the recessed hole57is concentric with the center of the prepared hole of the femur112. The diameter of the recessed hole57is larger than the diameter of the prepared hole. No prepared hole may be provided in some operating methods. Formation of the recessed hole57is also performed in the state in which a perfusion liquid, such as a physiological saline solution, is circulated in the articular cavity136. In the case of using a STG tendon, the recessed hole57has a rectangular shape, for example, with shorter sides of 4 mm, longer sides of 5 mm, and a depth of approximately 15 mm. In the case of using a BTB tendon, the recessed hole57has a rectangular shape, for example, with shorter sides of 5 mm, longer sides of 10 mm, and a depth of approximately 40 mm. As another example, in the treatment with the STG tendon and the BTB tendon, a through hole with a depth of approximately 60 to 70 mm may be formed in the position instead of the recessed hole57.

When the distal end treatment portion32is pressed against the bone112in a state in which vibration is transmitted, the part of the bone112which the distal end treatment portion32contacts is crushed. Accordingly, a recessed hole57is formed in the bone112along the central axis C of the distal end treatment portion32of the probe31.

In this state, the exposed portion55is sufficiently long. Specifically, the length of the exposed portion55in the central axis C direction is 60 to 80 mm. For this reason, even when the distal end treatment portion32reaches the position in which the recessed hole57is formed in the femur112, a space of approximately 20 to 40 mm is secured between the femur medial condyle112A and the distal end portion51A of the cylindrical member51. With this structure, the cylindrical member51does not interfere with the femur medial condyle112A when the recessed hole57is formed. This structure enables formation of the recessed hole57sufficiently deep in the femur112or a through hole without interference of the cylindrical member51with the femur medial condyle112A. In addition, the probe main member unit54is protected with the protective member61. When the arthroscope21is brought into contact with the probe31vibrated with ultrasonic waves, the probe31may be damaged or the arthroscope21may be damaged. In the present embodiment, it is particularly required to insert the probe31and the arthroscope21into a deep valley-like portion called intercondylar portion112B (seeFIG. 5) between the femur medial condyles112A to perform treatment. According to the present embodiment, even if the probe31vibrating with ultrasonic waves contacts the arthroscope21during treatment, the probe31or the arthroscope21is not damaged, because the protective member61protects the probe main member unit54.

The treatment device14according to the present embodiment enables treatment of removal and cutting also for the peripheral tissues (such as the cartilage) around the bone. This structure enables the operator to efficiently perform treatment, without needs for changing the treatment devices14in accordance with the tissue serving as the treatment target. Debris generated when the bone and the cartilage are crushed are properly discharged to the probe main member unit54side, and discharged to the outside of the body together with the perfusion liquid. When the depth of the recessed hole57reaches a predetermined size, preparation of the recessed hole57or the through hole is finished.

The method for fixing one end and the other end opposite to one end of the grafted tendon is the same as that of the above embodiment. In this manner, the anterior cruciate ligament reconstructive operation is finished.

According to the present embodiment, the distal end portion of the cylindrical member51is positioned on the proximal end portion31A side of the distal end treatment portion32at a distance of 60 to 80 mm from the distal end treatment portion32. This structure secures, in the exposed portion55of the probe31, a length sufficiently longer than 30 mm serving as an average length between the position in which the bone hole (recessed hole57) is formed in the femur112and the femur medial condyle112A. This structure markedly reduces the possibility that the cylindrical member51interferes with the femur medial condyle112A when the recessed hole57or a through hole is formed in the femur112.

According to the present embodiment, the ultrasonic surgical instrument includes the protective member61covering the probe31and in close contact with the probe31in the position on the proximal end portion31A side of the distal end treatment portion32, and the diameter of the protective member61is smaller than the diameter of the cylindrical member51. With this structure, the probe31is covered with the protective member61having a diameter smaller than the diameter of the cylindrical member51. This structure reduces the risk of interference of the probe31and the protective member61with the femur medial condyle112A in formation of the recessed hole57in the femur112. In addition, even when the protective member61contacts the femur medial condyle112A, the femur medial condyle112A is not damaged by the contact, because the surface of the probe31is protected with the protective member61.

In this case, the ultrasonic surgical instrument includes the second protective member71interposed between the skin incision portion of the patient and the protective member61, and the space62is provided between the protective member61and the second protective member71. This structure enables heat insulation between the protective member61and the second protective member71by the air and the like existing in the space62between the protective member61and the second protective member71. This structure prevents transmission of heat on the protective member61side to the second protective member71side, and prevents adverse influence on the tissues existing around the second protective member71due to heat.

In another exemplary embodiment of the treatment unit25illustrated inFIG. 13, the protective member61covers a part extending from the proximal end portion31A side of the probe31to the substantially center portion of the probe main member unit54. In the exposed portion55in a position extending out of the cylindrical member51, a portion that is not covered with the protective member61has a length D of, for example, 40 mm to 50 mm.

For this reason, when the recessed hole57is formed in the femur112with the probe31, the portion of the probe31corresponding to the femur medial condyle112ais protected with the protective member61. With this structure, even when the protective member61contacts the femur medial condyle112A, the femur medial condyle112A is not damaged by the contact, because the surface of the probe31is protected with the protective member61.

The following is an explanation of another exemplary embodiment of the treatment system100with reference toFIG. 14toFIG. 17. The following explanation mainly illustrates aspects of the present embodiment different from those of the above exemplary embodiments, and an explanation or illustration of aspects that are the same as those in the above embodiments are omitted.

As illustrated inFIG. 14andFIG. 15, the treatment tool24of the treatment system10includes a housing48, a cylindrical member51(external cylinder) extended from the housing48along the central axis C, a probe31inserted through the inside of the cylindrical member51, and a cylindrical attachment member81configured to be attachable to and detachable from a distal end portion51A of the cylindrical member51.

As illustrated inFIG. 14, the cylindrical member51includes, at the distal end portion51A, a first engagement portion82to fix the attachment member81. The first engagement portion82includes a pair of projecting pieces83further projecting from the distal end portion51A of the cylindrical member51toward the distal end C2side, and a pair of hole portions84formed in the respective projecting pieces83.

As illustrated inFIG. 14andFIG. 15, the attachment member81is attachable to and detachable from the cylindrical member51to cover the distal end portion51A of the cylindrical member51. The attachment member81is formed in a substantially truncated quadrangular pyramid shape having a diameter decreasing toward the distal end treatment portion32. The attachment member81may be formed in a substantially truncated cone shape (tapered shape). The attachment member81includes, in an internal surface thereof, a second engagement portion85engageable with the first engagement portion82. The second engagement portion85is formed of a pair of hook portions86projecting toward the central axis C of the attachment member81. The hook portions86can be fitted into the respective hole portions84of the first engagement portion82, and in this state the attachment member81is fixed on the cylindrical member51. By contrast, the attachment member81can be pulled by the user's hand toward the distal end treatment portion32, and is easily detachable from the cylindrical member51as a result of disengagement of the second engagement portion85from the first engagement portion82.

The attachment member81may be changed to another attachment member81′ (attachment member illustrated with two-dot chain lines inFIG. 15) having a different length in the central axis C direction. As another example, the attachment member81may have a structure in which the distal end portion81A and therearound are formed in a pleated flexible shape such that the distal end portion81A is capable of expanding and contracting between a first position P1(illustrated with solid lines inFIG. 15) and a second position P2(illustrated with two-dot chain lines inFIG. 15) in the central axis C direction with respect to the cylindrical member51. These structures enables easy adjustment of the length of the portion of the probe31exposed from the attachment member81(another attachment member81′) in accordance with the type of treatment or the body size of the patient.

The length of the exposed portion55of the probe31in the central axis C direction may be equal to that in the embodiment illustrated inFIGS. 3, 6, and 7, or equal to that in the embodiment illustrated inFIGS. 9, 11, and 12.

The following is an explanation of a function of the treatment system10according to the present embodiment with reference toFIG. 16andFIG. 17, with an example of the case of performing an anterior cruciate ligament reconstructive operation in the knee joint100. This explanation mainly illustrates the case of forming a recessed hole57in the bone112using the treatment unit25.

In the same manner as the above embodiments, a grafted tendon (STG tendon, BTB tendon) is extracted by a publicly-known method. In parallel with this, a prepared hole of a small diameter is formed in a predetermined position of the femur112using a drill or the like to pierce the femur112, and a prepared hole of a small diameter is formed in a predetermined position of the tibia114using a drill or the like to pierce the tibia114.

A recessed hole57is formed from the inside of the articular cavity136using the treatment system10according to the present embodiment such that the recessed hole57is concentric with the center of the prepared hole of the femur112. The diameter of the recessed hole57is larger than the diameter of the prepared hole. No prepared hole may be provided in some operating methods. Formation of the recessed hole57is also performed in the state in which a perfusion liquid, such as a physiological saline solution, is circulated in the articular cavity136. The values of the shorter sides, the longer sides, and the depth of the recessed hole57are equal to those in the case of using the grafted tendon (STG tendon, BTB tendon) according to the embodiment illustrated inFIGS. 9, 11, and 12.

When the distal end treatment portion32is pressed against the bone112in a state in which vibration is transmitted, the part of the bone112which the distal end treatment portion32contacts is crushed. Because the attachment member81has a diameter decreasing toward the distal end treatment portion32, the diameter of the attachment member81is small in the vicinity of the femur medial condyle112A. This structure prevents interference of the distal end portion and therearound of the attachment member81with the femur medial condyle112A, and enables the operator to smoothly form the recessed hole57in the femur112. The treatment device14of the present embodiment enables treatment of removal and cutting even for peripheral tissues (such as the cartilage) around the bones112and114. This structure enables the operator to perform efficient treatment without changing the treatment devices14according to the tissue serving as the treatment target. Debris generated when the bone112and the cartilage are crushed are properly discharged to the probe main member unit54side, and discharged to the outside of the body together with the perfusion liquid. When the depth of the recessed hole57reaches a predetermined value, preparation of the recessed hole57is finished.

The method for fixing one end and the other end opposite to one end of the grafted tendon is equal to that of the embodiment illustrated inFIGS. 3, 6, and 7. In this manner, the anterior cruciate ligament reconstructive operation is finished.

According to the present embodiment, the ultrasonic surgical instrument includes the cylindrical attachment member81attachable to and detachable from the cylindrical member51to cover the distal end portion51A of the cylindrical member51. This structure enables protection of the distal end portion51A of the cylindrical member51with the attachment member81. With this structure, when the recessed hole57is formed in the femur112, even when the distal end portion51A of the cylindrical member51nearly interfere with the femur medial condyle112A, the attachment member81is enabled to abut against the femur medial condyle112A, instead of the distal end portion51A of the cylindrical member51. This structure prevents the risk of damage to the femur medial condyle112A with the distal end portion51A of the cylindrical member51during treatment.

The diameter of the attachment member81decreases toward the distal end treatment portion32. This structure enables protection of the distal end portion51A of the cylindrical member51by covering the distal end portion51A with the attachment member81, and reduces the risk of contact of the cylindrical member51itself with the femur medial condyle112A.

The attachment member81is replaceable with another attachment member81′ having a different length in the central axis C direction of the probe31. As another example, the attachment member81is capable of expanding and contracting in the central axis C direction of the probe31. These structures enable proper fine adjustment of the length of the portion exposed in the probe31in accordance with the body size of the patient and/or the type of treatment. This structure improves safety of the operation and user's convenience.

In another exemplary embodiment, a kit may be provided that includes the ultrasonic surgical instrument according to any of the above discussed embodiments, and the interchangeable attachment members81and81′.

Exemplary embodiments have been specifically explained with reference to the drawings. The present disclosure is not limited to the embodiments described above, but includes all implementations performed within a range not departing from the gist of the disclosure.

EXPLANATION OF REFERENCE NUMERALS