CN211325899U - Extensible prosthesis handle and knee joint prosthesis applying same - Google Patents

Abstract

The utility model belongs to the technical field of medical false body, a can prolong formula false body handle and use its knee joint false body is disclosed. The extendable prosthesis stem comprises: a barrel; the broach assembly is sleeved in the cylinder body in a sliding manner and comprises a movable sleeve sleeved in the cylinder body in a sliding manner and a broach prosthesis connected with one end of the movable sleeve; the driven driving component is rotatably connected in the cylinder body and forms threaded connection with the movable sleeve; and the driving component is fixed on the wall of the cylinder body and is connected with the driven driving component. Wherein, the initiative drive assembly sets up to drive driven drive assembly circumferential direction to drive movable sleeve and take place axial displacement and location. The utility model discloses a but extension formula false body handle can be applied to the still use in the patient of growth state of skeleton effectively.

Description

Extensible prosthesis handle and knee joint prosthesis applying same

Technical Field

The utility model belongs to the technical field of medical false body, concretely relates to can prolong formula false body handle and use its knee joint false body.

Background

The knee joint is composed of a lower end of a femur, an upper end of a tibia and a patella, and is the largest joint with the most complex structure and more damage opportunities for a human body. Knee prostheses are surgical implants used to replace the knee, which are used to treat and replace a damaged knee. The existing knee joint prosthesis mainly comprises: the tibial plateau support comprises a femoral prosthesis for coupling to a femur of a human body and a tibial plateau support for coupling to a tibia of a human body, and a liner positioned between the femoral prosthesis and the tibial plateau support.

However, in the case of teenagers or children with immature bones, the patient's bones remain in a growing state. When such patients need to perform knee joint prosthesis replacement surgery, the existing market knee joint prosthesis cannot adjust the length of the prosthesis after being implanted into a human body, so that various serious problems such as unequal limb length, pelvis inclination, scoliosis and the like are easily caused in the bone production process of the patients. The existing method for solving the problems is to regularly adjust the length of the knee joint prosthesis along with the growth of the bone, namely, the femoral prosthesis of the knee joint prosthesis needs to be replaced to meet the bone growth requirement of a patient, which not only directly increases the economic burden of the patient, but also causes the problem of the infection rate of the postoperative patient due to the large trauma of the operation.

In response to the deficiencies of the prior art, there is a great need in the art for an extendable prosthetic stem that can be effectively used by patients whose bones are still in a growing state.

SUMMERY OF THE UTILITY MODEL

In order to be effectively applied to the use of a patient with a bone still in a growing state, the utility model aims to provide an extensible prosthesis handle.

The utility model discloses a can prolong formula false body handle includes: a barrel; the broach assembly is sleeved in the cylinder body in a sliding manner and comprises a movable sleeve sleeved in the cylinder body in a sliding manner and a broach prosthesis connected with one end of the movable sleeve; the driven driving component is rotatably connected in the cylinder body and forms threaded connection with the movable sleeve; and the driving component is fixed on the wall of the cylinder body and is connected with the driven driving component. Wherein, the initiative drive assembly sets to and can drives driven drive assembly circumferential direction and location, and the movable sleeve sets to and can take place axial displacement through threaded connection when driven drive assembly circumferential direction.

Furthermore, the driving assembly comprises a first rotating shaft vertically penetrating through the wall of the barrel and a first bevel gear coaxially arranged on the first rotating shaft and positioned in the barrel, the driven driving assembly comprises a screw rod with one end in threaded connection with the inside of the movable sleeve and a second bevel gear coaxial with the other end of the screw rod, the first bevel gear and the second bevel gear are in meshing fit, and the expansion spiral angle of the first bevel gear is smaller than the friction angle of the second bevel gear.

Furthermore, the driven driving assembly further comprises a fixed shaft sleeve which is coaxial with the barrel and is fixedly connected with the barrel, a second rotating shaft which is sleeved in the fixed shaft sleeve and is used for coaxially connecting the screw rod with the second bevel gear, and a rotating shaft sleeve which is positioned between the second rotating shaft and the fixed shaft sleeve and is fixedly connected with the second rotating shaft, wherein clamping walls matched with the fixed shaft sleeve are formed at two axial ends of the rotating shaft sleeve, and the clamping walls are arranged to limit the second rotating shaft to generate axial displacement.

Further, the transmission ratio of the first bevel gear to the second bevel gear is 1: 2.

Further, the extendable prosthesis handle further comprises a limiting component formed between the inner wall of the barrel body and the outer wall of the movable sleeve, and the limiting component is arranged to limit the movable sleeve to rotate and separate relative to the barrel body when the movable sleeve is subjected to axial displacement.

Further, the limiting assembly comprises a convex part fixed on the inner wall of the barrel body and a limiting sliding groove formed on the outer peripheral wall of the movable sleeve and matched with the convex part, and the limiting sliding groove is configured to extend from one end, far away from the medullary needle prosthesis, of the movable sleeve along the axial direction of the movable sleeve.

Further, the extendable prosthesis handle may further comprise an abutment member extending through the wall of the barrel, the abutment member being arranged to be movable in a direction towards and away from the second bevel gear for abutment and disengagement with the second bevel gear, and/or the abutment member being arranged to be movable in a direction towards and away from the movable sleeve for abutment and disengagement with the movable sleeve.

Furthermore, a three-dimensional porous structure layer is formed on the surface of the broach prosthesis.

Furthermore, the extendable prosthesis handle also comprises an extramedullary fixing plate which is detachably connected with one end of the movable sleeve connected with the broach prosthesis, the extramedullary fixing plate comprises a plate part extending along the length direction of the broach prosthesis, and a clamping space is formed between the plate part and the broach prosthesis.

The utility model also provides a knee joint prosthesis, including above-mentioned can prolong formula false body handle, with can prolong formula false body handle fixed connection's thighbone condyle prosthesis, be used for connecting human shin bone's shin bone prosthesis, hold in the palm and be located thighbone condyle prosthesis and the platform of shin bone platform between holding in the palm with shin bone prosthesis fixed connection's tibial plateau and hold in the palm the liner. Wherein, the femoral condyle prosthesis is connected with one end of the cylinder body of the extensible prosthesis handle far away from the intramedullary pin prosthesis.

The utility model discloses a can prolong formula false body handle has the following advantage in several respects:

1) the utility model discloses can prolong formula false body handle is applied to when teenagers or the not mature infant's of skeleton knee joint false body's replacement, the length of accessible adjustment broach false body is in the patient's skeleton of growth state with better adaptation to can avoid effectively needing to change the demand in order to satisfy patient's skeleton growth to knee joint false body's thighbone false body among the prior art, and then can reduce patient's economic burden and the great wound of operation effectively, and reduce the problem that postoperative patient's infection rate risees and take place.

2) The utility model discloses can prolong formula false body handle can avoid driven drive assembly antiport, form the auto-lock promptly, like this, when the broach false body atress after the replacement, the auto-lock of formation can avoid effectively that can prolong formula false body handle is inaccurate at the broach false body extension size that leads to because of the atress after the replacement, and the broach false body shortens and the not isometric, pelvic slope of limbs that arouse even in the use, serious problems such as backbone lateral curvature.

3) The three-dimensional porous structure layer that the false body surface of broach formed can be favorable to human sclerotin to fuse fast and fix, and then can improve the recovery effect of patient's postoperative more effectively, improves the utility model discloses can prolong the stability of formula false body handle after the replacement.

Drawings

FIG. 1 is a schematic view of an extendable prosthesis stem according to an embodiment of the present invention;

FIG. 2 is a schematic view of the coupling of the broach assembly shown in FIG. 1 to a driven drive assembly;

FIG. 3 is a schematic structural view of the broach assembly shown in FIG. 1;

FIG. 4 is a schematic structural view of the driven drive assembly shown in FIG. 1;

fig. 5 is a schematic structural diagram of a knee joint prosthesis according to an embodiment of the present invention.

Detailed Description

In order to better understand the purpose, structure and function of the present invention, the extendable prosthesis handle of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 illustrates the structure of an extendable prosthesis stem 100 according to an embodiment of the present invention. As shown in fig. 1, the extendable prosthesis stem 100 includes: a cylinder body 1; the broach assembly 2 is sleeved in the barrel body 1 in a sliding mode, and as shown in a combined mode in fig. 2 and fig. 3, the broach assembly 2 comprises a movable sleeve 21 sleeved in the barrel body 1 in a sliding mode and a broach prosthesis 22 connected with one end of the movable sleeve 21; the driven driving component 3 is rotatably connected in the cylinder body 1 and forms threaded connection with the movable sleeve 21; and the driving component 4 is fixed on the wall of the barrel body 1 and is connected with the driven driving component 3. Wherein, initiative drive assembly 4 sets up to drive driven drive assembly 3 circumferential direction and location, and movable sleeve 21 sets up to take place axial displacement when driven drive assembly 3 circumferential direction.

The extendable prosthesis handle 100 of the embodiment of the present invention can be used to replace the femoral stem of a knee prosthesis. When the extendable prosthesis stem 100 is being replaced, the broach prosthesis 22 is intended to be fixedly connected to the patient's femur and the end of the barrel 1 remote from the broach prosthesis 22 is intended to be fixedly connected to the femoral condyle of the knee prosthesis. When the broach prosthesis 22 needs to be extended, the driving assembly 4 is rotated by using a tool to drive the driven driving assembly 3 to rotate, the driven driving assembly 3 and the movable sleeve 21 form threaded connection, so that when the movable sleeve 21 is set to be capable of axially displacing when the driven driving assembly 3 rotates in the circumferential direction, the circumferential rotation of the movable sleeve 21 forms limitation, the movable sleeve 21 can move in the axial direction of the movable sleeve 21 under the threaded matching of the driven driving assembly 3, and the broach prosthesis 22 can be extended to be used by a patient. When the extended length of the broach prosthesis 22 meets the requirements of a patient, the driving component 4 is set to be capable of positioning the driven driving component 3 in a circumferential direction, so that the driven driving component 3 cannot rotate reversely, and the stability of the broach prosthesis 22 after extension can be effectively ensured.

The extendable prosthesis handle 100 of the present invention has the following advantages:

1) the utility model discloses can prolong formula false body handle 100 can only be through rotating the length that initiative drive assembly 4 can adjust broach false body 22, like this, work as the utility model discloses can prolong formula false body handle 100 when being applied to teenagers or the replacement of the not mature infant's of skeleton knee joint false body, can prolong formula false body handle 100 accessible adjustment broach false body 22's length is in the patient's skeleton of growth state with better adaptation to can avoid effectively needing to change the demand in order to satisfy patient's bone growth to the femoral prosthesis of knee joint false body among the prior art, and then can reduce patient's economic burden and the great wound of operation effectively, and reduce the problem that postoperative patient's infection rate risees and take place.

2) The utility model discloses can prolong formula false body handle 100 sets to through will initiative drive assembly 4 and can drive 3 circumferential direction of driven drive assembly and fix a position, thereby can avoid driven drive assembly 3 antiport, form the auto-lock promptly, like this, when broach false body 22 atress after the replacement, the auto-lock of formation makes the unable antiport of threaded connection that movable sleeve 21 and driven drive assembly 3 formed, thereby can avoid effectively that can prolong formula false body handle 100 is inaccurate because of the broach false body 22 extension size that the atress leads to after the replacement, the limb that broach false body 22 shortened and arouse in the use even is inequality, the pelvis slope, serious problems such as backbone lateral curvature.

In a preferred embodiment as shown in fig. 1, the driving assembly 4 may include a first rotating shaft 41 vertically penetrating the wall of the cylinder 1 and a first bevel gear 42 coaxially disposed on the first rotating shaft 41 and located inside the cylinder 1, and as shown in fig. 4, the driven driving assembly 3 may include a screw 31 having one end in threaded connection with the inside of the movable sleeve 21 and a second bevel gear 32 coaxial with the other end of the screw 31, the first bevel gear 42 and the second bevel gear 32 are in meshing engagement, and the angle of the spiral of the expansion of the first bevel gear 42 is smaller than the angle of friction of the second bevel gear 32.

With the above arrangement, the first bevel gear 42 and the second bevel gear 32 are formed in a manner similar to a worm gear connection. When the broach prosthesis 22 needs to be lengthened, the first rotating shaft 41 is rotated by a tool to drive the first bevel gear 42 to rotate, the first bevel gear 42 is meshed with the second bevel gear 32, so that the second bevel gear 32 drives the screw rod 31 to rotate, the screw rod 31 is in threaded connection with the inner part of the movable sleeve 21, and the movable sleeve 21 can move axially under the condition that the rotation of the movable sleeve 21 in the circumferential direction is limited, so that the broach prosthesis 22 is lengthened. In the spiral transmission, when the angle of the spiral of the first bevel gear 42 is smaller than the angle of friction of the second bevel gear 32, the gear engagement between the first bevel gear 42 and the second bevel gear 32 can have a self-locking characteristic, that is, when the pressure on the broach prosthesis 22 is transmitted to the screw 31 through the movable sleeve 21, no matter how large the force is, the screw 31 cannot rotate reversely under the engagement between the first bevel gear 42 and the second bevel gear 32, so that the broach prosthesis 22 can be effectively ensured to be effectively fixed after being lengthened, and the aforementioned problems can be avoided. In addition, the design of this auto-lock makes the auto-lock structure of the extendable prosthesis handle 100 of the embodiment of the present invention is simpler, thereby effectively reducing the difficulty of processing the extendable prosthesis handle 100.

Preferably, the unwinding helix angle of the first bevel gear 42 may be 45 ° and the friction angle of the second bevel gear 32 may be 60 °.

Preferably, as shown in fig. 1, the active driving assembly 4 may further include a first shaft sleeve 43 sleeved between the first rotating shaft 41 and the wall of the cylinder 1, a pin 44 for engaging with the first shaft sleeve 43 and being fixed on the cylinder 1, and a plug 45 connected to the first rotating shaft 41 and located outside the cylinder 1, wherein a hexagonal bolt opening (not shown) is formed on the plug 45, so that it can rotate the first rotating shaft 41 by using a hexagonal wrench tool to drive the first bevel gear 42 to rotate, thereby making the operation of extending the broach prosthesis 22 simpler.

In a preferred embodiment as shown in fig. 4, the driven driving assembly 3 may further include a fixed shaft sleeve 33 coaxially and fixedly connected with the cylinder 1, a second rotating shaft 34 sleeved in the fixed shaft sleeve 33 for coaxially connecting the screw 31 and the second bevel gear 32, and a rotating shaft sleeve 35 located between the second rotating shaft 34 and the fixed shaft sleeve 33 and fixedly connected with the second rotating shaft 34. Wherein, the two axial ends of the rotating shaft sleeve 35 may be formed with a clamping wall (not shown) matched with the fixed shaft sleeve, and the clamping wall is configured to limit the axial displacement of the second rotating shaft 34. Preferably, the driven driving assembly 3 may further include a screw hole 331 (shown in fig. 4) formed on the fixing boss 33 and a screw 36 (shown in fig. 1) threadedly coupled with the screw hole 331 from the outside of the cylinder 1 to fix the fixing boss 33 in the cylinder 1. Through the setting, can make driven drive assembly 3 wholly fix in barrel 1 along its axis, screw rod 31 takes place to rotate for fixed axle sleeve 33 through second pivot 34 and rotatory axle sleeve 35 to take place axial displacement through rotatory axle sleeve 35 portion, thereby make the utility model discloses driven drive assembly 3 can implement effectively.

In a preferred embodiment, the gear ratio of the first bevel gear 42 to the second bevel gear 32 may be 1: 2. By this arrangement, a parameterised adjustment of the extended broach prosthesis 22 can be achieved, i.e. the first bevel gear 42 driving the driving drive assembly 4 rotates one revolution, which means that the driven drive assembly 3 rotates half a revolution, and the length of the extended broach prosthesis 22 driven by the driven drive assembly 3 is half the circumference of the driven drive assembly 3. Preferably, the first bevel gear 42 may have a diameter of 10mm and a number of teeth of 10, and the second bevel gear 32 may have a diameter of 20mm and a number of teeth of 20.

In a preferred embodiment as shown in fig. 1, the extendable prosthesis stem 100 may further comprise a restraining assembly 5 formed between the inner wall of the barrel 1 and the outer wall of the movable sleeve 21, and the restraining assembly 5 may be configured to restrain the movable sleeve 21 from rotating and coming out with respect to the barrel 1 when the movable sleeve 21 is axially displaced. Through the arrangement, the movable sleeve 21 can be effectively ensured to move along the axial direction, and the problem that the movable sleeve is separated from the barrel body 1 due to the overlong adjustment length of the broach prosthesis 22 can be avoided. Specifically, the limiting assembly 5 may include a protrusion 51 fixed on the inner wall of the barrel 1, and a limiting slide groove 52 formed on the outer circumferential wall of the movable sleeve 21 and cooperating with the protrusion 51, and the limiting slide groove 52 may be configured to extend from an end of the movable sleeve 21 remote from the broach prosthesis 22 in the axial direction of the movable sleeve 21. As shown in fig. 2, the limit chute 52 has an opening 521 formed at an end of the movable sleeve 21, and when the assembled whole is placed in the barrel 1 after the broach assembly 22 is mounted and engaged with the driven driving assembly 3, the protrusion 51 can slide into the limit chute 52 of the movable sleeve 21 through the opening 521 until the first bevel gear 42 is engaged with the second bevel gear 32, and then the fixed sleeve 33 is fixed (as described above) by the screw 36 to complete the whole mounting.

With the arrangement, on one hand, the limiting sliding groove 52 can be arranged in parallel to the axial direction of the movable sleeve 21, so that the moving direction of the movable sleeve 21 can be effectively limited; on the other hand, in order to facilitate the adjustment of the whole of the broach assembly 22 and the driven driving assembly 3 in the cylinder 1, an adjustment region 522 may be further formed at one end of the limiting chute 52 close to the opening 521, the adjustment region 522 not only can effectively ensure the good engagement between the first bevel gear 42 and the second bevel gear 32, but also can effectively limit the position of the movable sleeve 21 when the movable sleeve 21 is adjusted to the maximum position by the limiting wall 523 formed by the adjustment region 522, thereby effectively avoiding the problem that the movable sleeve 21 is separated from the cylinder 1. Preferably, the convex portion 51 may be provided as a key fitted to the cylindrical wall of the cylindrical body 1, a jack screw screwed to the cylindrical wall of the cylindrical body 1, or the like.

Returning to fig. 1, preferably, the extendable prosthesis stem 100 may further comprise an abutment member 6 passing through the wall of the barrel 1, the abutment member 6 may be configured to be movable in a direction toward and away from the second bevel gear 32 to effect abutment and disengagement with the second bevel gear 32, and/or the abutment member 6 may be configured to be movable in a direction toward and away from the movable sleeve 21 to effect abutment and disengagement with the movable sleeve 21. With this arrangement, the abutting member 6 abuts against and disengages from the second bevel gear 32, and the fitting clearance after the driven drive assembly 3 is mounted into the cylinder 1 can be effectively eliminated, that is, when the fitting clearance exists, the abutting member 6 abuts against the second bevel gear 32, so that the fitting accuracy is improved. When the abutting assembly 6 abuts against and separates from the movable sleeve 21, the fixing effect of the movable sleeve 21 can be improved, that is, when the intramedullary nail prosthesis 22 is fixed by self-locking of the first bevel gear 42 and the second bevel gear 32 after the extension of the intramedullary nail prosthesis 22, the stability of the fixing of the movable sleeve 21 can be further improved by abutting the abutting assembly 6 against the movable sleeve 21, so that the movable sleeve 21 can be secondarily fixed, and the above-mentioned problem caused by the shortening of the intramedullary nail prosthesis 22 can be further avoided.

It should be noted here that when the abutting member 6 is disposed to abut against the second bevel gear 32, the abutting member 6 should elastically abut against the second bevel gear 32 to avoid affecting the rotation of the second bevel gear 32, for example, the abutting member 6 may be selected as a ball screw. When the contact member 6 is disposed to contact the movable sleeve 21, the contact member 6 may be selected from a fixing member such as a screw that is screwed to the cylindrical wall of the cylindrical body 1.

In a preferred embodiment as shown in fig. 3, the surface of the broach prosthesis 22 may be formed with a solid porous structure layer 7. The three-dimensional porous structure layer 7 can be constructed into a plurality of pores formed by a plurality of wire diameters and the plurality of wire diameters in a mutual staggered connection mode, and the pores are communicated with each other, so that the structure of the three-dimensional porous structure layer can be closer to the bone trabecula structure of a human body, the adhesion, proliferation and differentiation capabilities of osteoblasts can be effectively improved, and the rapid fusion and fixation of the bone of the human body and the three-dimensional porous structure layer 7 are effectively promoted. Through this setting, broach false body 22 is connected the back with human thighbone, and the sclerotin can grow into in the hole of three-dimensional porous structure layer 7 fast naturally like this to can be favorable to broach false body 22 to fuse fast and fix with human sclerotin at the postoperative, and then can improve the recovery effect of patient's postoperative more effectively, improve the utility model discloses the stability of extensible false body handle 100 after the replacement.

Preferably, the porosity of the porous structure layer 7 may range from 20% to 60%, and the pore size may range from 40 μm to 100 μm. The three-dimensional porous structure layer 7 with a high porosity can well induce bone ingrowth, and the three-dimensional porous structure layer 7 with a small pore size can well induce bone crawling. It should be noted that the cross section of each pore formed by the wire diameter is not a regular circle, but the cross sectional shape thereof may be various shapes, and in view of this, reference to "diameter" of each pore herein should be understood to mean the diameter of the circle when the cross section of each pore is equivalent to a circle. Since the diameter of the cross section equivalent to a circle is calculated from the actual area of the cross section, the value of the diameter obtained is an accurate value.

In a preferred embodiment, an abutting platform (not shown in the figure) for abutting against a cross section of a femur of a human body may be further formed at one end of the broach prosthesis 22 connected to the cylinder 1, and a three-dimensional porous structure layer 7 may be formed on a surface of the abutting platform, so that after the broach prosthesis 22 is connected to the femur of the human body, the three-dimensional porous structure layer 7 formed on the abutting platform can be better fused with bone, so as to improve the effects of bone crawling and bone ingrowth, and further improve the fixing effect of the extendable prosthesis handle 100 according to an embodiment of the present invention.

Preferably, the three-dimensional porous structure layer 7 can be processed by laser cladding technology. The laser cladding technology is a process method for placing a selected coating material on the surface of the broach prosthesis 22, melting the coating material and a thin layer on the surface of the broach prosthesis 22 simultaneously through laser irradiation, and forming a surface coating which has extremely low dilution degree and is metallurgically bonded with the material of the broach prosthesis 22 after rapid solidification, namely forming a three-dimensional porous structure layer 7 on the surface of the broach prosthesis 22. The self intensity of broach false body 22 can be guaranteed effectively on the one hand to the three-dimensional porous structure layer 7 that forms through this method processing, thereby can guarantee effectively the utility model discloses the stability of can extending formula false body handle 100 after implanting the human body, on the other hand, the optional kind of material of three-dimensional porous structure layer 7 is also more various, thereby can more match with human affected part, has improved the utility model discloses can extend formula false body handle 100's suitability.

Preferably, the material of the three-dimensional porous structure layer 7 may be titanium alloy, pure titanium or tantalum metal, and the like. Preferably, the three-dimensional porous structure layer 7 is made of a titanium alloy material, preferably Ti6Al 4V.

In a preferred embodiment as shown in fig. 1, the extendable prosthesis stem 100 may further include an extramedullary fixation plate 8 detachably coupled to an end of the movable sleeve 21 to which the broach prosthesis 22 is coupled, and the extramedullary fixation plate 8 may include a plate portion 81 extending in a length direction of the broach prosthesis 22, with a clamping space 82 formed between the plate portion 81 and the broach prosthesis 22. After the broach prosthesis 22 is connected with the femur of the human body, the bone part of the human body can be clamped in the clamping space 82, so that the fixation effect of the extendable prosthesis handle 100 after being connected with the human body can be further improved by fixedly connecting the plate part 81 and the broach prosthesis 22 by using screws, and the connection stability is ensured. Preferably, the extendable prosthesis stem 100 may further include a set screw 83 for securing the plate portion 81 with the broach prosthesis 22.

In a preferred embodiment, the material of the extendable prosthesis stem 100 may preferably be a cobalt chromium molybdenum alloy. The alloy material has high corrosion resistance, oxidation resistance and wear resistance, and can be better suitable for manufacturing long-term implants in harsh environments in vivo.

Fig. 5 shows a structure of a knee joint prosthesis 200 according to an embodiment of the present invention. The knee joint prosthesis 200 includes the above-mentioned extendable prosthesis stem 100, a femoral condyle prosthesis 201 fixedly connected to the extendable prosthesis stem 100, a tibial prosthesis 202 for connecting to a tibia of a human body, a tibial plateau support 203 fixedly connected to the tibial prosthesis 202, and a plateau support pad 204 located between the femoral condyle prosthesis 201 and the tibial plateau support 203. Wherein the femoral condyle prosthesis 201 is connected to an end of the barrel 1 of the extendable prosthesis stem 100 distal from the broach prosthesis 22. In combination with the above, the knee joint prosthesis 200 according to the embodiment of the present invention can be better applied to the replacement of the knee joint prosthesis 200 of teenagers or children with immature bones by adjusting the length of the broach prosthesis 22, so as to avoid the need of replacing the femoral prosthesis of the knee joint prosthesis in the prior art to meet the requirement of the bone growth of the patient, thereby effectively reducing the economic burden of the patient and the large trauma of the operation, and effectively reducing the infection rate of the postoperative patient; on the other hand, the utility model discloses knee joint prosthesis 200 can form the auto-lock, like this, when knee joint prosthesis 200 atress after the replacement, the auto-lock of formation can avoid knee joint prosthesis 200 effectively to be inaccurate because of the broach prosthesis 22 extension size that the atress leads to after the replacement, and broach prosthesis 22 shortens and the not isometric, pelvic tilt of limbs that arouse even in the use, serious problems such as backbone lateral curvature. In addition, the three-dimensional porous structure layer 7 formed on the surface of the broach prosthesis 22 of the knee prosthesis 200 can also effectively improve the stability of fixation of the knee prosthesis 200 to the human body.

It is to be noted that unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the present invention belongs.

In the description of the present application, it is to be understood that the terms "length," "inner," "outer," "axial," "circumferential," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the scope of the embodiments of the present invention, and are intended to be covered by the claims and the specification. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present invention is not limited to the particular embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (10)

1. An extendable prosthesis stem, comprising:

a barrel;

the broach assembly is sleeved in the barrel in a sliding manner and comprises a movable sleeve sleeved in the barrel in a sliding manner and a broach prosthesis connected with one end of the movable sleeve;

the driven driving component is rotatably connected in the cylinder and forms threaded connection with the movable sleeve;

the driving component is fixed on the cylinder wall of the cylinder body and is connected with the driven driving component;

the driving assembly is arranged to drive the driven driving assembly to rotate in the circumferential direction and to be positioned, and the movable sleeve is arranged to be capable of being in threaded connection with the driven driving assembly to generate axial displacement during circumferential rotation.

2. The extendable prosthesis handle of claim 1, wherein the driving assembly comprises a first rotating shaft vertically penetrating through the wall of the cylinder and a first bevel gear coaxially disposed on the first rotating shaft and located in the cylinder, the driven driving assembly comprises a screw rod with one end in threaded connection with the inside of the movable sleeve and a second bevel gear coaxial with the other end of the screw rod, the first bevel gear and the second bevel gear form a meshing fit, and the expansion helix angle of the first bevel gear is smaller than the friction angle of the second bevel gear.

3. The extendable prosthesis handle of claim 2, wherein the driven driving assembly further comprises a fixed shaft sleeve coaxially and fixedly connected with the cylinder, a second rotating shaft sleeved in the fixed shaft sleeve and coaxially connecting the screw and the second bevel gear, and a rotating shaft sleeve positioned between the second rotating shaft and the fixed shaft sleeve and fixedly connected with the second rotating shaft, wherein clamping walls matched with the fixed shaft sleeve are formed at two axial ends of the rotating shaft sleeve, and the clamping walls are configured to limit the axial displacement of the second rotating shaft.

4. The extendable prosthesis stem of claim 2, wherein the first bevel gear and the second bevel gear have a gear ratio of 1: 2.

5. The extendable prosthesis stem of any one of claims 1 to 4, further comprising a stop assembly formed between the inner wall of the barrel and the outer wall of the movable sleeve, the stop assembly being configured to limit rotation and expulsion of the movable sleeve relative to the barrel upon axial displacement of the movable sleeve.

6. The extendable prosthesis stem of claim 5, wherein the stop assembly comprises a protrusion fixed to the inner wall of the barrel, and a stop runner formed on the outer peripheral wall of the movable sleeve and cooperating with the protrusion, the stop runner being configured to extend from an end of the movable sleeve remote from the broach prosthesis in an axial direction of the movable sleeve.

7. The extendable prosthesis handle of any one of claims 2 to 4, further comprising an abutment member passing through the barrel wall of the barrel, the abutment member being arranged to be movable in a direction towards and away from the second bevel gear for abutment and disengagement with the second bevel gear, and/or the abutment member being arranged to be movable in a direction towards and away from the movable sleeve for abutment and disengagement with the movable sleeve.

8. The extendable prosthesis stem of any one of claims 1 to 4, wherein the surface of the broach prosthesis is formed with a three-dimensional porous structure layer.

9. The extendable prosthesis stem of any one of claims 1 to 4, further comprising an extramedullary fixation plate removably attached to the end of the movable sleeve to which the broach prosthesis is attached, the extramedullary fixation plate comprising a plate portion extending along a length of the broach prosthesis, the plate portion and the broach prosthesis forming a clamping space therebetween.

10. A knee joint prosthesis comprising an extendable prosthesis stem according to any one of claims 1 to 9, a femoral condyle prosthesis fixedly connected to the extendable prosthesis stem, a tibial prosthesis for connection to a human tibia, a tibial plateau tray fixedly connected to the tibial prosthesis, and a plateau tray liner between the femoral condyle prosthesis and the tibial plateau tray, wherein the femoral condyle prosthesis is connected to an end of the barrel of the extendable prosthesis stem remote from the broach prosthesis.

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