CN108836267B - Knee joint soft tissue balance measuring device - Google Patents

Abstract

The invention provides a knee joint soft tissue balance measuring device, which comprises: a datum plate, a movable plate, a base, a driver, a clearance indicator, an outward rotation indicator, and a load indicator, wherein the datum plate is fixedly connected to the base; the movable plate is rotatably connected to the driver; the gap indicator is connected with the driver; the outward rotation indicator is connected with the movable plate; the load indicator is connected with the driver; the driver is arranged on the base body. The measuring device and the measuring method thereof provided by the invention can simultaneously and comprehensively measure the extension gap, the knee bending gap, the physiological external rotation angle of the thighbone and the applied load, and can carry out pre-judgment according to the measured parameters and the original soft tissue balance condition before the knee bending gap is formed, so as to determine the knee bending gap according with physiological characteristics, thereby obtaining the expected perfect soft tissue balance.

Description

Knee joint soft tissue balance measuring device

The present application is a divisional application entitled "knee joint soft tissue balance measuring device and measuring method thereof" with application number 201510390837.6 and application date 2015, 07/06.

Technical Field

The invention relates to an operation tool used in a total knee joint replacement operation, in particular to a knee joint soft tissue balance measuring device.

Background

The knee joint mainly comprises thighbone, shinbone and patella, a joint capsule is attached to the periphery of each bone joint cartilage, ligaments are arranged around the joint capsule for reinforcement, and the joint capsule, the ligaments, muscles, tendons, nerves, blood vessels and the like at the knee joint form soft tissue of the knee joint.

With the advent of aging society, knee joint pathology has become a common disease affecting the quality of life of the elderly. Total knee arthroplasty is an effective method for treating advanced knee arthropathy. Total knee replacement refers to the replacement of a knee joint, which has been seriously damaged and fails to function normally, with an artificial prosthesis, thereby eliminating pain of the knee joint and restoring its stability and mobility. Fig. 1A and 1B are schematic views of a knee joint before and after total knee replacement, the knee joint prosthesis mainly including a femoral prosthesis, a tibial prosthesis, a low friction spacer (usually made of ultra high molecular weight polyethylene) between them, and a patellar prosthesis.

To install the prosthesis, the femur and tibia are resected so that the resected bone profile matches the mounting surface of the prosthesis. For example, for the tibia, the resection step mainly includes resection of the proximal end of the tibia (referring to the end near the heart); for the femur, the resection step mainly includes resection of the distal end of the femur (referring to the end away from the heart), and resection of the anterior, posterior, oblique, and intercondylar condyles of the femur.

After the distal femoral resection and the formation of the distalfemoral resection surface 200 are completed, as shown in fig. 2A, the anteriorfemoral condyle 201, the posteriorfemoral condyle 202, the first chamfer between thedistal resection surface 200 and the anteriorfemoral condyle 201, and the second chamfer between thedistal resection surface 200 and the posteriorfemoral condyle 202 are resected by a special resection tool, such as a four-in-oneresection plate 205, and then theintercondylar 203 is resected.Holes 204 in the femoraldistal resection surface 200 are used to position and mount theresection plate 205.

The femoral representation after the resection is shown in FIG. 2B, in which the resulting distal femoral cut 200a, anterior femoral condyle cut 201a, posterior femoral condyle cut 202a,intercondylar cut 203a,first chamfer 206a connecting the anteriorfemoral condyle cut 201a and the distalfemoral cut 200a, andsecond chamfer 207a connecting the posterior femoral condyle cut 202a and the distalfemoral cut 200a are seen. Fig. 2C is a schematic view of the femoral prosthesis mounted to an osteotomy of a femur.

In total knee replacement, the key steps of restoring and rebuilding the balance between the extension gap and the flexion gap of the knee joint, the balance between the medial and lateral gaps and the tension balance of the corresponding soft tissues affect the curative effect of the operation.

In the present total knee arthroplasty, when the knee joint is in a straightened state, the user performs the resection of the distal femur and the proximal tibia by using a commonly used resection instrument provided by a knee prosthesis supplier, then uses a commonly used gap measurement block to check and evaluate the resection precision, and performs corresponding resection and/or soft tissue treatment as appropriate, so as to obtain a proper straightened gap.

In the case of knee flexion gaps, which are generally the case in knee flexion, the user determines the placement of a four-in-one resection plate based on the size of the femoral condyle and the degree of external rotation given on the tool provided by the manufacturer, and by resection of the femoral posterior condyles, the precision of the resection is checked and evaluated using a universal gap gauge, and checked against the extension gap, and then the appropriate resection and/or soft tissue treatment is performed as appropriate to achieve the appropriate knee flexion gap.

In the above process, not only a plurality of surgical instruments are required to be used in cooperation, but also the external rotation angle of the tool provided by the manufacturer is given and often does not conform to the external rotation condition of the femur of the patient, so that the method for manually setting the external rotation angle of the femur is likely to bring great difficulty to subsequent osteotomy and soft tissue balance. In addition, since the balance between the extension and flexion gaps and the balance between the inner and outer soft tissues are completely dependent on the experience of the user, even if the extension and flexion gaps are equal in size, the corresponding loads, i.e., the corresponding soft tissue tension balance, cannot be quantified. Therefore, the soft tissue balance is not really realized, and the external rotation angle cannot be determined according to the physiological condition of the patient before the knee bending gap is formed so as to carry out the soft tissue balance.

Some prior patent documents describe some measuring instruments for total knee replacement, such as a total knee replacement soft tissue balance equal tension measuring instrument disclosed in chinese patent application No. 200620014638.1 and a knee inner and outer balance tension measuring instrument disclosed in chinese patent application No. 200820124249.3, but these measuring instruments can only measure the extension gap size of the knee joint and the flexion gap size after the femoral posterior condyles are cut, cannot measure the external rotation angle of the femoral posterior condyles, and cannot quantify the corresponding applied load, so that the soft tissue balance cannot be performed according to the physiological condition of the patient before the flexion gap is formed, only the extension gap size and the flexion gap size are measured, and the true soft tissue balance cannot be realized.

Disclosure of Invention

The first objective of the present invention is to provide a knee joint soft tissue balance measuring device and a measuring method thereof, so that a user can determine the balance between the balanced knee bending gap and the straightening gap, the balance between the inner and outer gaps and the corresponding tension balance according to the physiological condition of the patient before the knee bending gap is formed, i.e. before the femoral posterior condyles are cut, thereby realizing real soft tissue balance, thereby reducing the uncertainty of the operation technique varying from person to person, and improving the postoperative effect of artificial total knee joint replacement.

In order to achieve the object, the present invention provides a knee joint soft tissue balance measuring device, comprising: a datum plate, a movable plate, a base, a driver, a clearance indicator, an outward rotation indicator, and a load indicator, wherein the datum plate is fixedly connected to the base; the movable plate is rotatably connected to the driver through a rotating shaft and driven by the driver to be far away from or close to the reference plate; the gap indicator is connected with the driver and is used for measuring the sizes of the extension gap and the flexion gap of the knee joint; the external rotation indicator is connected with the movable plate and is used for measuring the angle of the distal femur section and/or the external rotation angle of the femoral posterior condyle; the load indicator is connected with the driver and is used for measuring the load applied to the femur and the tibia when the soft tissue is balanced; the driver is arranged on the base body.

The invention provides a knee joint soft tissue balance measuring method, which comprises the following steps: under the state that the knee joint is straightened, the reference plate is contacted with the proximal tibial section, and under the driving of the driver, the movable plate is contacted with the distal femoral section; judging whether to perform osteotomy and/or soft tissue balance again according to the reading displayed by the external rotation indicator, if not, performing the next step, and if so, performing osteotomy and/or soft tissue balance again until the reading displayed by the external rotation indicator is zero; obtaining a value for a first gap (i.e., a straightened gap) based on the reading on the base, and obtaining a value for a first load based on the reading on the load indicator; removing the measuring device from between the distal femoral cut and the proximal tibial cut; under the flexion state of the knee joint, the reference plate is contacted with the proximal tibial section plane, and the movable plate is contacted with the femoral posterior condyles under the driving of the driver; expanding the proximal resection surfaces of the femoral condyle and the tibia to a proper position through the first gap and the selected thickness of the posterior condyle of the femoral prosthesis; or according to the numerical value of the first load, the femoral posterior condyle and the tibial plateau are expanded to a proper position; at the moment, obtaining values of a second load and a second clearance according to the readings on the load indicator and the clearance indicator; judging whether further soft tissue treatment is needed or not according to the comparison result of the numerical value of the first load and the numerical value of the second load; or judging whether further soft tissue treatment is needed or not according to the comparison result of the numerical value of the first clearance and the numerical value of the second clearance; and meanwhile, acquiring the external rotation angle of the femoral posterior condyle according to the reading on the external rotation indicator.

Through the technical scheme, the invention provides the multifunctional integrated knee joint soft tissue balance comprehensive measuring device and the measuring method thereof, and after the measuring device is used, a gap measuring block is not required to be used. While providing the magnitude of the applied external load, to maximize the personal experience of the physician numerically. Therefore, before the knee bending gap is formed, the knee bending gap according with the characteristics can be determined according to the measured parameters and the physiological condition of the patient, so that the expected perfect soft tissue balance is obtained. The big data analysis of the specific degree of the external rotation can provide powerful visual evidence for the clinical research of China.

Another object of the present invention is to provide a knee joint soft tissue balance measuring device, which is convenient for a user to reduce the influence of patella roll-over on soft tissue balance when performing extension gap and knee bending gap measurement and soft tissue balance.

In order to achieve the aim, the invention provides a knee joint soft tissue balance measuring device which comprises a reference plate, a movable plate, a base body, a driver and a clearance indicator, wherein the movable plate is arranged on the base body; wherein the reference plate is fixedly connected to the base; the movable plate is rotatably connected to the driver through a rotating shaft and driven by the driver to be far away from or close to the reference plate; the gap indicator is connected with the driver and is used for measuring the sizes of the extension gap and the flexion gap of the knee joint; the movable plate and the reference plate are offset relative to the base; the driver is arranged on the base body.

Through the technical scheme, the movable plate and the reference plate are offset relative to the base body, so that a user can perform soft tissue balance in a flexion-extension gap in situ of the patella, and the influence of patella turnover on the soft tissue balance in the traditional operation is reduced to the maximum extent.

It is still another object of the present invention to provide a knee joint soft tissue balance measuring device, so as to directly output the result of measurement and balance to the subsequent surgical instruments after measuring and balancing the extension gap and the knee bending gap, thereby forming a seamless joint.

In order to achieve the aim, the invention provides a knee joint soft tissue balance measuring device which comprises a reference plate, a movable plate, a base body, a driver, a gap indicator and an osteotomy guider, wherein the movable plate is arranged on the base body; the reference plate is fixedly connected to the base; the movable plate is rotatably connected to the driver through a rotating shaft and driven by the driver to be far away from or close to the reference plate; the gap indicator is connected with the driver and is used for measuring the sizes of the extension gap and the flexion gap of the knee joint; the driver is arranged on the base body; the osteotomy guide is perpendicular to the reference plate and moves synchronously with the movable plate, and is provided with at least one pair of guide holes, and the connecting line of the two guide holes is parallel to the reference plate.

Through the technical scheme, the positioning nail can be driven into the positioning hole on the osteotomy guide to form seamless butt joint with the subsequent operation step of installing the osteotomy plate, so that the proper external rotation angle of the femoral condyle is not set by people, the proper angle is determined according to the physiological condition of the patient body, and the expected perfect soft tissue balance is obtained after the knee bending gap is formed.

Drawings

FIG. 1A and FIG. 1B are schematic diagrams of a knee joint before and after total knee replacement, respectively;

FIGS. 2A-2C are schematic views of a femoral resection and prosthesis installation;

FIG. 3 is a schematic structural diagram of a knee joint soft tissue balance measuring device according to a preferred embodiment of the present invention;

FIG. 4 is an exploded view of a portion of the components of the measuring device shown in FIG. 3;

FIG. 5 is an exploded view of a portion of the components of the drive shown in FIG. 3;

fig. 6 is a schematic structural view of the movable plate and the first connecting member shown in fig. 3;

FIG. 7 is an exploded view of the camber measure shown in FIG. 3;

FIG. 8 is a schematic view of the osteotomy guide mounted on the movable plate of FIG. 6;

FIG. 9 is a schematic structural view of another embodiment of a knee joint soft tissue balance measuring device;

FIG. 10 is a schematic view of the knee soft tissue balance measurement device with the osteotomy guide installed.

Detailed Description

The present invention provides a knee joint soft tissue balance measuring device and a measuring method thereof, which are further described in detail below with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are not necessarily to scale, merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

Please refer to fig. 3, which is a schematic structural diagram of a knee joint soft tissue balance measuring device according to a preferred embodiment of the present invention, the measuring device mainly includes areference plate 10, amovable plate 20, abase 30, adriver 40, agap indicator 50, anoutward rotation indicator 60, aload indicator 70 and alock 80. Their structure, function and their connection will be described in detail below.

In the present embodiment, thereference plate 10 and themovable plate 20 are two plates having similar shapes, and both have a uniform thickness and a flat surface. Themovable plate 20 is rotatably disposed above thereference plate 10, and has a balanced state and a rotating state, when themovable plate 20 is in the balanced state, themovable plate 20 is parallel to thereference plate 10, and when themovable plate 20 is in the rotating state, themovable plate 20 is not parallel to thereference plate 10.

Thereference plate 10 defines a reference plane, and for convenience of description, the longitudinal direction of thereference plate 10 is defined as an X direction, and the width direction is defined as a Y direction, and the reference plane may be expressed by an X-Y plane, and a direction perpendicular to the reference plane is defined as a Z direction. Each direction is defined positively as shown in fig. 3. Themovable plate 20 is parallel to thereference plate 10, which means that: the upper surface of themovable plate 20 is parallel to the reference plane.

Thereference plate 10 and themovable plate 20 may be in a regular shape or an irregular shape, and thereference plate 10 and themovable plate 20 shown in fig. 3 are substantially in a waist shape, and have an inward concave notch in the middle in the width direction (see fig. 3 and 6), and the shape is designed to mainly match with the physiological structure of the subject to be measured. Of course, in other embodiments, the reference plate and the movable plate may also be two plates, sheets, or any other suitable shapes with different shapes and sizes, which is not limited by the present invention.

Thebase 30 extends in the Z direction, and therefore, thebase 30 is disposed perpendicularly with respect to thereference plate 10. As shown in fig. 3, thebase 30 has a cylindrical structure with a hollow interior. Of course, one skilled in the art will recognize that thesubstrate 30 may have a rectangular parallelepiped structure or other structures, and the present invention is not limited thereto. Thereference plate 10 is disposed to be fixed relative to thebase 30, and themovable plate 20 is connected to thedriver 40, the specific connection relationship of which will be described in detail below.

Thegap indicator 50 includes agap scale substrate 51 and a gap indicating member 52 (see fig. 4 and 5), in the present embodiment, thegap scale substrate 51 is integrated with thebase 30, and a gap scale is disposed on thegap scale substrate 51 for displaying the distance between themovable plate 20 and thereference plate 10. Thegap indication member 52 is connected to theactuator 40, and thus, thegap indication member 52 moves together with themovable plate 20 along the base 30 in the Z direction with respect to thereference plate 10 by the actuation of theactuator 40. In this process, the distance between themovable plate 20 and thereference plate 10, which can be read on thegap scale substrate 51, is changed synchronously.

Referring to fig. 3 to 5, as mentioned above, thedriver 40 is connected to themovable plate 20 for driving themovable plate 20 to move up and down relative to thereference plate 10, in this embodiment, thedriver 40 includes afirst handle 41, asecond handle 42, a first drivingmember 43, a firstelastic member 44, asecond driving member 45, and a secondelastic member 46. Thefirst handle 41 is fixed to the base 30 at one end and held by a user at the other end, and thereference plate 10 is fixed to one end of thefirst handle 41 and thus indirectly fixed to thebase 30. One end of thesecond handle 42 is rotatably connected to the first drivingmember 43, and the other end is held by the user, and thefirst pivot portion 411 of thefirst handle 41 is connected to thesecond pivot portion 421 of thesecond handle 42. The first drivingmember 43, the firstelastic member 44, the second drivingmember 45, and the secondelastic member 46 are sequentially stacked in the base 30 from bottom to top.

Referring to fig. 3 to 6, a first connecting member 22 (see fig. 6) and a second connecting member 11 (see fig. 3) are further disposed outside thebase 30, the first connectingmember 22 is used for connecting themovable plate 20 and the second drivingmember 45, so as to connect themovable plate 20 and thedriver 40, and the second connectingmember 11 is used for connecting thereference plate 10 and thefirst handle 41. The first connectingmember 22 is disposed in parallel with the second connectingmember 11. When the user presses thefirst handle 41 and thesecond handle 42, thesecond handle 42 drives the first drivingmember 43 to move upward, so as to drive the second drivingmember 45 to move upward in thebase 30, and drive the first connectingmember 22 to drive themovable plate 20 to move upward relative to thereference plate 10.

Referring to fig. 4 and 5, thebase 30 is further provided with a first slidinggroove 31, the base 30 further includes apositioning column 32 therein, the first drivingmember 43, the firstelastic member 44, the second drivingmember 45 and the secondelastic member 46 are sleeved on thepositioning column 32, and the first slidinggroove 31 is disposed on thebase 30 along the Z direction, so that the first drivingmember 43 is connected with the externalsecond handle 42 and moves up and down relative to thebase 30.

Thesecond driver 45 includes acentral portion 451, a pair ofouter extension arms 452, and anouter protrusion 453. Thecentral portion 451 is connected to theexternal extension arm 452 and disposed inside thebase 30, theexternal extension arm 452 is sleeved outside thebase 30, and theexternal protrusion 453 is respectively connected to theexternal extension arm 452 and thefirst connector 22. Thecentral portion 451, the pair ofouter extension arms 452, and theouter protrusion 453 may be integrally formed, but the present invention is not limited thereto.

Preferably, as thesecond drive member 45 moves up and down in the Z direction under the drive of thesecond handle 42, theouter extension arm 452 also moves up and down along the outer surface of thebase 30. In the present embodiment, thegap indication member 52 is disposed on theouter extension arm 452 for indicating the gap scale, and preferably, the gap indication member and the outer extension arm are integrated, so that the whole structure is more compact and precise. Thebase 30 is further provided with a second sliding groove (not shown) for allowing a portion of thecentral portion 451 connected to theouter extension arm 452 to pass therethrough.

Referring to fig. 3, 6 and 7, themovable plate 20 has arotation shaft 21, and therotation shaft 21 is connected to thefirst connection member 22 so that themovable plate 20 can rotate about an axis of therotation shaft 21. Themovable plate 20 is further connected to theoutward rotation indicator 60 so that theoutward rotation indicator 60 is driven to operate while themovable plate 20 rotates. Specifically, theoutward turning indicator 60 includes an outwardturning scale substrate 61 and an outwardturning indicating member 62, the outwardturning scale substrate 61 is fixed on the first connectingmember 22, and the outer surface is provided with outward turning scales, and therotating shaft 21 is linked with the outwardturning indicating member 62, so as to drive the outwardturning indicating member 62 to move on the outwardturning scale substrate 61.

Specifically, theoutward turning indicator 60 further comprises alinkage member 63, thelinkage member 63 is linked with the rotatingshaft 21 through shape matching, small teeth are arranged on thelinkage member 63, alinkage portion 621 is arranged on the outwardturning indicating component 62, small teeth are also arranged on thelinkage portion 621, thelinkage portion 621 is driven by thelinkage member 63 to be linked, and driving of the outwardturning indicating component 62 can be achieved.

Of course, while the above is only one embodiment of thedriver 40 driving themovable plate 20 and themovable plate 20 to link theoutward rotation indicator 60, in fig. 9, another embodiment of thedriver 40 can be seen, which is similar to the above-described implementation, the firstelastic member 44, the second drivingmember 45 and the secondelastic member 46 are still sleeved on thepositioning pillar 32, but the difference is that the first drivingmember 43 is fixed with thepositioning pillar 32 in thebase 30, and the first drivingmember 43 is located outside thebase 30.

After referring to the above embodiments, a person skilled in the art may make various changes such that themovable plate 20 moves up and down along the Z direction (for example, belt transmission, chain transmission, gear transmission, worm transmission and screw transmission) and rotates about the axis of the rotating shaft under the driving of thedriver 40, and the outwardrotation indicating member 62 moves on the outward rotation scale substrate 61 (for example, thelinkage 63 and thelinkage 621 perform friction transmission, or thelinkage 621 and therotating shaft 21 directly link) under the rotation of themovable plate 20 by theoutward rotation indicator 60. The invention is not limited in this regard.

Referring to fig. 3 and 5, in the present embodiment, theload indicator 70 includes aload scale base 71 and aload indicating member 72. Theload scale base 71 is provided on one side of thebase 30, which also extends in the Z direction, and load scales are provided on both sides of theload scale base 71 in this direction. The loadscale base plate 71 is fixed to the first drivingmember 43, and theload indicating member 72 is connected to thedriver 40, so that when thesecond handle 42 drives the first drivingmember 43 to move, the loadscale base plate 71 and theload indicating member 72 are driven to move relatively.

It should be appreciated that theload indicating member 72 may also be disposed on theouter extension arm 452, and preferably is integrally formed with theouter extension arm 452. As shown in fig. 3 to 5, thegap indication part 52 is located below theexternal extension arm 452 and close to the gap scale on the gapscale base plate 51 to indicate the gap scale, and theload indication part 72 is located at the end of theexternal extension arm 452 and points to the loadscale base plate 71 to indicate the load scale, so that the user can obtain relevant parameters more conveniently and quickly, and the structure of the measuring device is more concise, compact and convenient to operate.

Referring to fig. 3 and 4, in the present embodiment, the lockingdevice 80 is disposed on thefirst handle 41 and includes a pair ofpressing portions 81, a lockingportion 82 and a pivotingportion 83. The twopressing portions 81 are located on both sides of the same end of thelocking device 80 for the user to press and conveniently operate the left or right knee, the lockingportion 82 is located at the other end of thelocking device 80 for locking or releasing theload indicator 70, and the pivotingportion 83 is located between thepressing portions 81 and the lockingportion 82 for connecting with thefirst handle 41.

Specifically, the lockingportion 82 has a plurality of small teeth thereon, and one side of theload indicator 70 also has a plurality of small teeth, and theload indicator 70 is locked by thelock 80 through engagement between the teeth. After the locking, the second handle cannot move theload indicator 70, and therefore cannot move the first drivingmember 43, and the positions of themovable plate 20 and thereference plate 10 are kept unchanged. When the user presses thepressing portion 81 of thelock 80, thelock portion 82 moves away from theload indicator 70, and theload indicator 70 is released and theactuator 40 is operated.

Preferably, a return member such as a torsion spring may be used at thepivot portion 83 so that thelock 80 is automatically returned to lock theload indicator 70 after the user releases thepressing portion 72. Of course, there are various structures and arrangements of thelocking device 80, and the locking of thedriver 40 may be realized by other mechanisms, for example, a locking device shown in fig. 9, which can lock thedriver 40 by abuckle 41a disposed on thefirst handle 41 and a clampingportion 42b disposed between thesecond handle 42 and thefirst handle 41, which is not limited in the present invention.

Referring to fig. 8 and 10, preferably, the knee soft tissue balance measuring device in the present embodiment further includes aosteotomy guide 90 detachably disposed above themovable plate 20 and perpendicular to thedatum plate 10, wherein theosteotomy guide 90 has at least one pair of guide holes, and a line of the pair of guide holes is parallel to a datum plane on which thedatum plate 10 is located. In this embodiment, osteotomy guide 90 is removably disposed vertically onfirst connector 22.

Referring to fig. 3 and 10, preferably, therotatable plate 20 and thereference plate 10 may be offset relative to thebase 30, that is, the projection of the axis of therotating shaft 21 of therotatable plate 20 and the central axis of thereference plate 10 on the XY plane does not pass through the projection of the central axis of the base 30 on the XY plane. Further, therotatable plate 20 and thereference plate 10 may be selectively offset to either of two different sides of the base 30 to accommodate the use requirements of either the left knee or the right knee.

Specifically, the first connectingmember 22 is detachably connected to the second drivingmember 45. The second connectingmember 11 is also detachably connected to thebase 30. Thereference plate 10 and the second connectingmember 11 may be integrally formed, but the present invention is not limited thereto. When the first connectingmember 22 together with therotatable plate 20 is detached from the second drivingmember 45 and the second connectingmember 11 together with thereference plate 10 is detached from thefirst handle 41, the first connectingmember 22 and the second connectingmember 11 are turned by 180 degrees, the first connectingmember 22 can still be connected to the second drivingmember 45, the second connectingmember 11 can be connected to thefirst handle 41, and the upper and lower surfaces of therotatable plate 20 can be printed with indication marks indicating positions, such as LEFT and RIGHT knees, to meet the use requirements of the LEFT or RIGHT knee.

Further, thefirst connector 22 and the second drivingmember 45 are engaged by a central symmetrical structure, for example, thefirst connector 22 has a connecting portion with a rectangular cross section, and the second drivingmember 45 has a corresponding rectangular hole. When the first connectingmember 22 is turned over 180 degrees, the first connecting member and the second connecting member can still be fixed by inserting the first connecting member into the rectangular hole of the second drivingmember 45. Of course, the central symmetrical structure may have a cross section of other shapes such as a square shape and a diamond shape. Likewise, thesecond connector 11 and thefirst handle 41 are also coupled through a central symmetrical structure.

The structure of the knee joint soft tissue balance comprehensive measuring device in the present embodiment is clear from the above description, and the following describes in detail the advantages of the measuring device compared to the existing measuring device, and a new measuring method that can be performed by using the measuring device, so that before the knee bending gap is formed, the knee bending gap according to the measured parameters and the physiological condition of the patient can be determined, and the expected perfect soft tissue balance can be obtained.

In total knee arthroplasty, a user performs distal femoral resection and proximal tibial resection according to actual requirements and corresponding surgical techniques, so as to obtain a distal femoral resection and a proximal tibial resection. The knee joint of the patient is straightened and the straightened gap between the distal femoral cut plane and the proximal tibial cut plane is measured by the knee joint soft tissue balance measuring device in this embodiment. Specifically, the user holds the first andsecond handles 41 and 42, inserts thereference plate 10 and themovable plate 20 between the distal femur section and the proximal tibia section, and drives themovable plate 20 away from thereference plate 10, bringing themovable plate 20 into contact with the distal femur section and thereference plate 10 into contact with the proximal tibia section.

At this time, if the outwardrotation indicating member 61 of theoutward rotation indicator 60 is not at the zero position, that is, it indicates that the distal femur section and the proximal tibia section are not parallel yet and the medial-lateral gap is not balanced, the user cuts the bone again and/or treats the soft tissue inside and outside the bone as appropriate, so as to adjust the distal femur section to be parallel to the proximal tibia section. The user may then read the value of the first gap (i.e., the straightened gap) between the distal femoral cut and the proximal tibial cut through the gap scale onbase 30, along with the value of the first load onload indicator 70 in this position.

The user then removes the measuring device, places the knee joint in a 90 degree flexed knee position according to appropriate surgical techniques, and reinserts the measuring device between the posterior femoral condyle and the tibia. It should be noted that, at the moment when the femoral posterior condyle has not been resected, the user holds thefirst handle 41 and thesecond handle 42 again, drives themovable plate 20 away from thereference plate 10 and contacts the femoral posterior condyle, and thereference plate 10 contacts the tibial proximal resection surface.

Because the femur has a certain external rotation angle, themovable plate 20 contacting with the femoral posterior condyle can also deflect, at this time, a user can directly read the external rotation degree displayed on theexternal rotation indicator 60, so as to know the external rotation angle of the femur of the patient at this time, the external rotation angle displays the real condition of the femoral posterior condyle of the patient, and the external rotation angle has important significance for subsequent big data analysis, and especially can provide powerful visual evidence for clinical research of the femoral posterior condyle of Chinese population.

The user can open the femoral posterior condyle and the proximal tibial resection surface to a proper position by the aid of themovable plate 20 and thereference plate 10 through the extension gap measured before and the posterior condyle thickness of the installed femoral prosthesis selected afterwards; or according to the first load data measured previously and the physiological condition of the patient, the proximal resection surfaces of the femoral posterior condyle and the tibia are expanded to the proper positions by using the instrument. At this time, it is necessary to read again the values of the second load and the second clearance on theload indicator 70 and theclearance indicator 50, and compare the value of the second load with the value of the first load, and the value of the second clearance with the value of the first clearance, to determine the size of the flexion and extension clearance and the corresponding tension balance, so as to achieve true soft tissue balance.

Therefore, after the knee joint soft tissue balance comprehensive measurement device provided by the embodiment is used, a user can prejudge whether soft tissue balance can be obtained after resection before femoral posterior condylar resection, and the size of the flexion-extension gap, the balance of corresponding tension and the determination of the femoral external rotation angle all conform to the soft tissue condition of a patient in the whole process, so that perfect soft tissue balance is really obtained.

It should be noted that the knee joint soft tissue balance comprehensive measurement device provided by the present invention further preferably includes abone cutting guide 90, and thebone cutting guide 90 has at least one pair of guide holes, and a connecting line of the pair of guide holes is parallel to the reference plane on which thereference plate 10 is located. Different positions of the guide hole can correspond to different types of femoral condyle prostheses. Therefore, when the user determines the extension gap, the knee bending gap, the second load reading and the first load reading, if the femoral posterior condyle is cut, perfect soft tissue balance can be obtained, theosteotomy guide 90 can be selected and used to select a proper guide hole, and two schlemen pins are nailed into the femoral posterior condyle, so that the subsequent osteotomy plate can perform osteotomy according to the position of the schlemen pins.

Therefore, the knee bending gap and the extension gap between the resected femoral posterior condyle surface and the femoral platform are balanced, the inner and outer side gaps are balanced, and the first load and the second load are balanced, so that perfect soft tissue balance is realized. In other words, the knee joint soft tissue balance measuring device provided by the invention can enable the measuring step of the previous step and the osteotomy step of the next step to be in seamless butt joint.

Preferably, theosteotomy guide 90 is removed or not installed during the measurement procedure, thereby facilitating the measurement procedure, and after the relative positions of the proximal resected surfaces of the femoral condyle and the tibia are determined, theosteotomy guide 90 is installed for the nailing procedure.

Further, in the description of the device for measuring the soft tissue balance of the knee joint, it has been mentioned that therotatable plate 20 and thereference plate 10 may be offset relative to thebase 30, which reduces trauma to the patient's patella and associated soft tissue. Specifically, in the total knee replacement, the user firstly needs to cut an operation opening at the knee joint of the patient, and the operation opening is positioned at one side of the patella, in the conventional operation, the user needs to open the musculature with the patella to perform measurement, and with the measuring device of the embodiment, because therotatable plate 20 and thedatum plate 10 can be selectively offset to the left side or the right side of thebase body 30, the user can perform measurement and soft tissue balance in situ on the patella, and the influence of the patella turnover on the soft tissue balance in the conventional operation is reduced to the maximum extent.

Further, for both the left and right knee joints, the surgical port is located on the medial side of the knee joint, and for the right knee joint, the rotatingplate 20 and thereference plate 10 need to be offset to the left of the base 30 (as shown in FIG. 3) in order to keep the patella in place; for the left knee joint, therotation plate 20 and thereference plate 10 need to be offset to the right of the base 30 in order to keep the patella in place. Thus, the user can selectively remove thefirst link 22 together with therotatable plate 20, remove thesecond link 11 together with thereference plate 10, turn it 180 degrees, and connect them to the second drivingmember 45 and thefirst handle 41, respectively, to selectively perform the right or left knee joint operation using the same measuring device. Therefore, the measuring device can be applied to both the left and right knee joints.

In summary, the present invention provides a multifunctional integrated knee joint soft tissue balance measuring device and a measuring method thereof, and after the measuring device of the present invention is used, a gap measuring block is not needed to be used. The proper external rotation angle of the femur is not forcibly set by people, but is determined according to the condition of the patient body. The big data analysis of the degree of the external rotation can provide powerful visual evidence for the clinical research of China. In addition, the measuring device of the invention can simultaneously provide the magnitude of the applied external load, and the personal experience of the doctor knife is quantified through numerical values to the greatest extent. The result output of the measuring device is realized through the osteotomy guider, and forms seamless butt joint with the use of subsequent surgical instruments. And the unique structural design of the measuring device (can be selectively offset) is suitable for the left knee joint and the right knee joint, and the doctor can perform soft tissue balance in the flexion-extension gap in situ of the patella, thereby reducing the influence on the soft tissue balance caused by patella overturn in the traditional operation to the maximum extent.

The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims.

Claims (3)

1. A knee joint soft tissue balance measurement device, comprising:

the bone cutting device comprises a reference plate, a movable plate, a base body, a driver, a gap indicator and a bone cutting guider;

wherein the reference plate is fixedly connected to the base; the movable plate is rotatably connected to the driver through a rotating shaft and driven by the driver to be far away from or close to the reference plate; the gap indicator is connected with the driver and is used for measuring the sizes of the extension gap and the flexion gap of the knee joint; the driver is arranged on the base body; the osteotomy guide is perpendicular to the reference plate and synchronously moves with the movable plate, and is provided with at least one pair of guide holes, and the connecting line of the two guide holes is parallel to the reference plate;

the driver comprises a first handle, a second handle, a first driving piece, a first elastic piece, a second driving piece and a second elastic piece; one end of the first handle is fixed on the base body, one end of the second handle is rotatably connected to the first driving piece, and the first handle and the second handle are rotatably connected; the first elastic piece, the second driving piece and the second elastic piece are sequentially overlapped in the base body from bottom to top.

2. The knee joint soft tissue balance measurement device of claim 1, further comprising a first connector and a second connector, the first connector being connected to the driver, the movable plate being connected to the first connector via the rotating shaft; the second connecting piece is fixed relative to the reference plate and fixed on the base body; the first connecting piece is arranged in parallel with the second connecting piece.

3. The knee soft tissue balance measurement device of claim 2, wherein the osteotomy guide is removably coupled to the first connector.

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