CN107260368B

CN107260368B - Prosthesis

Info

Publication number: CN107260368B
Application number: CN201710661342.1A
Authority: CN
Inventors: 陈齐欧; 张立争; 张劼
Original assignee: Shanghai Microport Medical Group Co Ltd
Current assignee: Minimally Invasive Investment Holdings Ltd
Priority date: 2017-08-04
Filing date: 2017-08-04
Publication date: 2020-01-24
Anticipated expiration: 2037-08-04
Also published as: CN107260368A; WO2019024666A1

Abstract

The invention provides a prosthesis comprising a housing, a first sleeve, a second sleeve and a third sleeve received in the housing, wherein: the second sleeve is configured to remain axially relatively stationary with respect to the housing; the second sleeve is coaxially sleeved outside the first sleeve; the first sleeve is connected with the third sleeve through a limiting assembly, the third sleeve extends from the proximal end to the distal end and extends out of the shell, and the limiting assembly limits the third sleeve to rotate around the axis of the second sleeve; under the action of an alternating magnetic field, the second sleeve has a first working state and a second working state, when the second sleeve is in the first working state, the second sleeve drives the first sleeve to move along the axial direction of the shell, and when the second sleeve is in the second working state, the second sleeve enables the first sleeve to keep relatively static relative to the second sleeve in the axial direction.

Description

Prosthesis

Technical Field

The invention relates to the technical field of medical instruments, in particular to a prosthesis.

Background

The early amputation treatment of children with tumors, especially the distal-femoral and proximal-tibial osteosarcomas with high incidence rate, is slowly replaced by limb protection treatment, an endoprosthesis is required to be installed after the tumor is removed by an operation of the children, and the traditional limb protection treatment means mainly comprise autologous bone transplantation, allogeneic bone transplantation and common prosthesis replacement. However, as the child grows, the healthy limb of the child grows longer along with the body, and the prosthesis implanted side cannot grow normally due to the damaged epiphysis, which causes the problem that the limbs of the child are not long enough. This not only gives the patient an unsightly appearance, but also brings inconvenience to the life of the patient, and can cause a series of complications such as pelvic tilt, scoliosis, joint damage caused by abnormal stress, and the like.

In order to solve the problem of unequal lengths of the limbs of children after limb protection, the conventional extensible prostheses are divided into two types: the prosthesis is an invasive and extensible prosthesis, although the prosthesis can be extended, the designed extension mechanism can be completed only by performing secondary operations, if the prosthesis is exposed by the operations, the prosthesis with the internal structural formula is twisted by a special tool, the prosthesis needs to be extended by repeated operations, the postoperative complications of the infant are increased, time and labor are wasted, and the economic burden is increased. Another type of prosthesis is an automatic extendable prosthesis, such as a prosthesis with an internal power supply and an external power supply, which has a complex design structure, a high failure rate, a limited service life and an uncertain extension length, and the connection of the internal and external power supplies through subcutaneous tissue can cause some complications.

Therefore, there is a need to design a safe non-invasive and extendable prosthesis.

Disclosure of Invention

One of the objectives of the present invention is to provide a prosthesis, which solves the problem of the existing prosthesis that is not safe for extension.

It is also an object of the present invention to provide a prosthesis to solve the problem of complex structure of the existing prosthesis.

It is also an object of the present invention to provide a prosthesis that solves the problem of existing prostheses that require invasive surgery to achieve extension.

It is also an object of the present invention to provide a prosthesis to solve the problem of the prior art that the prosthesis is prone to failure.

It is another object of the present invention to provide a prosthesis to solve the problem of complications caused by the presence of an in vivo power source in the existing prosthesis.

In order to solve the above technical problem, the present invention provides a prosthesis, which includes a housing, and a first sleeve, a second sleeve and a third sleeve accommodated in the housing, wherein:

the second sleeve is configured to remain axially relatively stationary with respect to the housing;

the second sleeve is coaxially sleeved outside the first sleeve;

the first sleeve is connected with the third sleeve through a limiting assembly, the third sleeve extends from the proximal end to the distal end and extends out of the shell, and the limiting assembly limits the third sleeve to rotate around the axis of the second sleeve;

under the action of an alternating magnetic field, the second sleeve has a first working state and a second working state, when the second sleeve is in the first working state, the second sleeve drives the first sleeve to move along the axial direction of the shell, and when the second sleeve is in the second working state, the second sleeve enables the first sleeve to keep relatively static relative to the second sleeve in the axial direction.

Optionally, in the prosthesis, the outer wall of the second sleeve has a plurality of third grooves, and the third grooves accommodate permanent magnets;

the second sleeve being arranged for rotation about a second sleeve axis;

when the second sleeve is in a first working state, the second sleeve rotates around the axis of the second sleeve in a direction under the action of the alternating magnetic field;

when the second sleeve is in the second state, the second sleeve rotates around the axis of the second sleeve in the other direction under the action of the alternating magnetic field.

Optionally, in the prosthesis, the outer wall of the first sleeve has a plurality of lugs, and the inner wall of the second sleeve has a plurality of first grooves and a plurality of second grooves, wherein:

the first grooves extend along the axial direction, and the second grooves extend along the circumferential direction;

each first groove is communicated with a plurality of second grooves, and the plurality of second grooves communicated with the first grooves are positioned on the same side of the first groove;

the lug is matched with the first groove and the second groove, so that the lug can move axially in the first groove when the second sleeve is in the first working state; when the second sleeve is in the second working state, the lug is placed in the second groove and keeps axially and relatively static relative to the second groove.

Optionally, in the prosthesis, the second sleeve is configured to be rotatable about a second sleeve axis;

under the action of an alternating magnetic field, the second sleeve rotates clockwise around the axis of the second sleeve, and when the first sleeve is driven to move axially and distally, the second groove is arranged on the left side of the first groove; under the action of the alternating magnetic field, the second sleeve rotates anticlockwise around the axis of the second sleeve, and when the first sleeve is driven to move axially and distally, the second groove is arranged on the right side of the first groove.

Optionally, in the prosthesis, an end of the second groove far away from the first groove is provided with an elastic body, and the elastic body is used for clamping the lug.

Optionally, in the prosthesis, the prosthesis further comprises a threaded shaft,

the outer part of the threaded shaft is provided with an external thread and is fixed with the shell, the first sleeve is coaxially sleeved outside the threaded shaft, and the inner wall of the first sleeve is provided with an internal thread matched with the external thread of the threaded shaft;

when the second sleeve is in the first working state, the second sleeve drives the first sleeve to rotate around the axis of the second sleeve so as to axially move.

Optionally, in the prosthesis, the distal end of the threaded shaft extends out of the first sleeve and extends into the third sleeve, the prosthesis further includes at least one first bolt and at least one fourth bolt, the first bolt is fixed to the proximal end of the threaded shaft, and at the same time, two ends of the first bolt extend to be fixed to the housing, and at least one fourth bolt is fixed to the distal end of the threaded shaft, and at the same time, two ends of the fourth bolt extend to pass through the third sleeve and then to be fixed to the housing, so that the threaded shaft is fixed to the housing.

Optionally, in the prosthesis, the restriction member comprises an end cap, a first thrust ball bearing, a second thrust ball bearing and a third pin,

the first thrust ball bearing and the second thrust ball bearing are positioned at the far end part of the first sleeve, and the end cover is positioned at the far ends of the first thrust ball bearing and the second thrust ball bearing and is detachably and fixedly connected with the first sleeve so that the first thrust ball bearing and the second thrust ball bearing are kept axially and relatively static relative to the first sleeve;

the end part of the connecting end of the third sleeve and the first sleeve is provided with an outer flange, and the outer flange is positioned between the first thrust ball bearing and the second thrust ball bearing;

the third sleeve is provided with a fourth groove extending axially, the third bolt penetrates through the fourth groove, and two ends of the third bolt extend to be fixedly connected with the shell.

Optionally, in the prosthesis, the limiting component comprises an end cap, a two-way thrust ball bearing and a third latch,

the bidirectional thrust ball bearing is positioned at the far end of the first sleeve, and the end cover is positioned at the far end of the bidirectional thrust ball bearing and is detachably connected with the first sleeve so as to enable the bidirectional thrust ball bearing to keep axially relative static relative to the first sleeve;

the third sleeve is fixedly connected with a shaft ring of the bidirectional thrust ball bearing;

the third sleeve is provided with a fourth groove, the third bolt penetrates through the fourth groove, and two ends of the third bolt extend to be fixedly connected with the shell.

Optionally, in the prosthesis, at least a distal end of the third sleeve is prism-shaped, and the prosthesis further includes a fifth sleeve accommodated in the housing, the fifth sleeve being located at the distal end of the housing and fixedly connected to the housing, the fifth sleeve having a first inner cavity, at least a portion of the first inner cavity having a shape matching the shape of the distal end of the third sleeve to limit rotation of the third sleeve.

Optionally, in the prosthesis, the prosthesis further includes a plurality of second pins, at least one axially extending fifth groove is provided between the outer wall of the fifth sleeve and the housing, and the second pins are inserted into the fifth groove to limit the fifth sleeve from rotating around the axis.

Optionally, in the prosthesis, the prosthesis further comprises a fourth sleeve, a third thrust ball bearing and a fourth thrust ball bearing,

the fourth sleeve is located to be received in the outer housing at a distal end of the second sleeve and is configured to remain axially relatively stationary with respect to the outer housing, the third thrust ball bearing is located between the second sleeve and the outer housing, and the fourth thrust ball bearing is located between the second sleeve and the fourth sleeve to effect that the second sleeve remains axially relatively stationary with respect to the outer housing and is rotatable about a second sleeve axis.

Optionally, in the prosthesis, the prosthesis further includes a fifth sleeve, a cap, the fifth sleeve is accommodated in the outer casing and is located at the distal end of the fourth sleeve, and the cap is located at the distal end of the outer casing and is detachably connected with the outer casing, so that the second sleeve, the fourth sleeve and the fifth sleeve are axially kept relatively static with respect to the outer casing; the housing cap has a second lumen such that the third sleeve extends through the second lumen and towards the distal end of the housing cap.

In the prosthesis provided by the invention, under the action of an alternating magnetic field, the second sleeve has a first working state and a second working state, when the second sleeve is in the first working state, the second sleeve drives the first sleeve to move along the axial direction of the shell, and when the second sleeve is in the second working state, the second sleeve makes the first sleeve keep relatively static in the axial direction relative to the second sleeve, so that the prosthesis can be extended to the outside of the shell of the prosthesis, and the prosthesis provided by the invention has the following beneficial effects: firstly, the prosthesis provided by the invention has simple design, only has simple mechanical structure and size matching, avoids the problem of complex control caused by a mechanism for providing power by a power supply, secondly, the alternating magnetic field is positioned outside the human body, power sources (such as a power supply, a battery and the like) do not need to be implanted in the human body, and complications caused by the power supply inside and outside the human body which needs to be connected through subcutaneous tissues are avoided, in addition, the alternating magnetic field outside the human body is easy to obtain and has high substitution, the failure of the alternating magnetic field outside the human body is avoided, such as the electric quantity of the battery is exhausted, the damage and the failure of components in the power supply are avoided, the potential failure of the complex mechanism is avoided, the reliability of the prosthesis is further improved, furthermore, the prosthesis provided by the invention only uses magnetic field force for pushing, the alternating magnetic field can be outside the human body, the connection with the first sleeve structure, the prosthesis is harmless to human body, overcomes the problem of poor safety of the prosthesis in the prior art, and further has low manufacturing and extending cost and simple extending mode. In a word, the extension mechanism of the invention has simple design and good effect.

Drawings

FIG. 1 is a schematic view of the overall structure of the prosthesis of the present invention;

FIG. 2 is a schematic view of a first sleeve structure according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a second sleeve according to an embodiment of the present invention;

FIG. 4 is a schematic view of the assembly of the first sleeve and the second sleeve according to one embodiment of the present invention;

FIG. 5 is a schematic view of the assembly of the first sleeve and the third sleeve according to one embodiment of the present invention;

shown in the figure: 10-a housing; 20-a threaded shaft; 31-a first sleeve; 311-a lug; 32-a second sleeve; 321-a first groove; 322-a second groove; 323-third groove; 324-an elastomer; 33-a third sleeve; 331-an outer flange; 332-a fourth groove; 34-a fourth sleeve; 35-a fifth sleeve; 41-a first bolt; 42-a second bolt; 43-a third bolt; 51-a first thrust ball bearing; 52-a second thrust ball bearing; 53-third thrust ball bearing; 54-a fourth thrust ball bearing; 80-end cap; 90-shell cap.

Detailed Description

The prosthesis according to the invention will be described in more detail below with reference to the figures and the 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 to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

The core idea of the invention is to provide a prosthesis to solve the problem of extended insecurity of existing prostheses.

To achieve the above idea, the present invention provides a prosthesis comprising a housing, a first sleeve, a second sleeve and a third sleeve accommodated in the housing, wherein: the second sleeve is configured to remain axially relatively stationary with respect to the housing; the second sleeve is coaxially sleeved outside the first sleeve; the first sleeve is connected with the third sleeve through a limiting assembly, the third sleeve extends from the proximal end to the distal end and extends out of the shell, and the limiting assembly limits the third sleeve to rotate around the axis of the second sleeve; under the action of an alternating magnetic field, the second sleeve has a first working state and a second working state, when the second sleeve is in the first working state, the second sleeve drives the first sleeve to move along the axial direction of the shell, and when the second sleeve is in the second working state, the second sleeve enables the first sleeve to keep relatively static relative to the second sleeve in the axial direction.

In the prosthesis provided by the invention, the second sleeve 32 has a first working state and a second working state under the action of the alternating magnetic field, and when the second sleeve 32 is in the first working state, the second sleeve 32 drives the first sleeve 31 to move axially along the housing 10, so that the first sleeve can extend towards the distal end of the prosthesis housing 10; when the second sleeve 32 is in the second operating state, the second sleeve 32 keeps the first sleeve 31 axially relatively stationary with respect to the second sleeve 32.

The prosthesis provided by the invention has the following beneficial effects: firstly, the prosthesis provided by the invention has simple design and only has simple mechanical structure and size matching, and avoids the problem of complicated control caused by a mechanism powered by a power supply. In addition, the external alternating magnetic field is easy to obtain, the replacement is high, the failure of a power source, such as the exhaustion of the electric quantity of a battery, the damage and failure of components in the power source, the potential failure of a complex mechanism and the like, is avoided, and the reliability of the prosthesis is further improved. Furthermore, the prosthesis provided by the invention is pushed only by using magnetic field force, the alternating magnetic field can be outside the human body, the connection with the first sleeve structure of the prosthesis is not needed, the prosthesis is not needed to be exposed, invasive surgery is not needed, the prosthesis is harmless to the human body, the problem of poor safety of the prosthesis in the prior art is solved, and further, the prosthesis provided by the invention is low in manufacturing and extending cost and simple in extending mode. In a word, the extension mechanism of the invention has simple design and good effect.

The term "distal" as used herein refers to the side closer to the direction of extension of the prosthesis; correspondingly, "proximal" and "proximal" are the sides facing away from the direction of extension of the prosthesis.

The following embodiments are directed to a controlled femoral lengthening prosthesis, but do not indicate that the prosthesis of the present invention can be used only in a femoral lengthening prosthesis, and can also be used in tibial lengthening prostheses, ulnar lengthening prostheses, and the like. In this embodiment, the housing is a femoral box portion of an extendable femoral prosthesis, which is made as a femoral joint in this embodiment, one end of the prosthesis is connected to the tibial joint, and the other end of the prosthesis is connected to the femoral insertion section, and the extension of the femoral insertion section can push the tibial joint and the femoral insertion section to separate.

As shown in fig. 1, the prosthesis comprises a shell 10, a first sleeve 31, a second sleeve 32 and a third sleeve 33, wherein: the second sleeve 32 is configured to remain axially relatively stationary with respect to the prosthesis; the second sleeve 32 is coaxially sleeved outside the first sleeve 31; the first sleeve 31 is connected to the third sleeve 33 by a restraining assembly, the third sleeve 33 extending from the proximal end to the distal end and out of the housing 10, the restraining assembly restraining the third sleeve 33 from rotating about the axis of the second sleeve 32; under the action of the alternating magnetic field, the second sleeve 32 has a first operating state and a second operating state, when the second sleeve 32 is in the first operating state, the second sleeve 32 drives the first sleeve 31 to move axially along the housing 10, and when the second sleeve 32 is in the second operating state, the second sleeve 32 keeps the first sleeve 31 axially relatively stationary with respect to the second sleeve 32. In this embodiment, the prosthesis further includes a threaded shaft 20, an external thread is disposed outside the threaded shaft 20 and fixed to the housing 10, the first sleeve 31 is coaxially sleeved outside the threaded shaft 20, and an internal thread matching the external thread of the threaded shaft 20 is disposed on an inner wall of the first sleeve 31; when the second sleeve 32 is in the first working state, the second sleeve 32 drives the first sleeve 31 to rotate around the second sleeve 32 in the axial direction, and further moves along the second sleeve 32 in the axial direction.

In this embodiment, the second sleeve 32 is not only arranged to remain axially relatively stationary with respect to the housing 10, but is also rotatable about the second sleeve axis. In particular, the prosthesis further comprises a fourth sleeve 34, a third thrust ball bearing 53 and a fourth thrust ball bearing 54. The fourth sleeve 34 is located at the distal end of the second sleeve 32, and the fourth sleeve 34 is configured to remain axially relatively stationary with respect to the housing 10, the third thrust ball bearing 53 is located between the proximal end of the second sleeve 32 and the housing, and the fourth thrust ball bearing 54 is located between the second sleeve 32 and the fourth sleeve 34, so as to achieve that the second sleeve 32 remains axially relatively stationary with respect to the housing 10 and is rotatable about the axis of the second sleeve 32.

Further, as shown in fig. 3, the outer wall of the second sleeve 32 has a plurality of third grooves 323, and the third grooves 323 accommodate the permanent magnets. The permanent magnet is fixed in the third groove 323 of the second sleeve 32, and in order to avoid shaking, the permanent magnet may also be glued in said third groove 323. The third groove 323 may be designed to open and retract toward the center, such as a dovetail groove, so that the permanent magnet is embedded in the third groove. The number of the permanent magnets can be 4 or 6, the permanent magnets are uniformly distributed on the same plane, the magnetization direction of each magnet is parallel to the plane, each permanent magnet synchronously rotates under a specific initial angle, and the rotating shaft is vertical to the circular plane to ensure that a rotating magnetic field with a constant size can be formed at the center of the circular plane. When the second sleeve is located at the center of the integrated external permanent magnet source, the second sleeve 32 can be driven to rotate. In this embodiment, when the second sleeve is in the first operating state, the second sleeve rotates around the axis of the second sleeve in one direction under the action of the alternating magnetic field, and when the second sleeve is in the second operating state, the second sleeve rotates around the axis of the second sleeve in the other direction under the action of the alternating magnetic field. More specifically, as shown in FIG. 3, when the second sleeve is in the first operating condition, rotation of the second sleeve counterclockwise about the second sleeve axis drives the first sleeve axially distally. Herein, "counter-clockwise" and "clockwise", "left side" and "right side" all refer to directions from the proximal end to the distal end of the prosthesis.

In addition, the second sleeve 32 has a plurality of first grooves 321 and a plurality of second grooves 322 on an inner wall thereof, wherein: the first grooves 321 extend along the axial direction of the second sleeve 32, the second grooves 322 extend along the circumferential direction of the inner wall of the second sleeve 32, and preferably, the second grooves 322 are perpendicular to the first grooves 321; each of the first grooves 321 is communicated with a plurality of the second grooves 322, and the plurality of the second grooves 322 communicated with the first grooves 321 are located on the same side of the first groove 321. In the second sleeve 32 shown in fig. 3, the second grooves 322 are all disposed on the right side of the first grooves 321 connected thereto. Adjacent second grooves are arranged at equal intervals along the axial direction, and the interval is actually prolonged every time, and is generally between 0.8mm and 1.2 mm. Or the spacing between the second grooves can be planned according to the growth characteristics of the children.

As shown in fig. 2, the outer wall of the first sleeve 31 has a plurality of lugs 311. The lug 311 is matched with the first groove 321 and the second groove 322, so that the lug 311 can move axially in the first groove 321 when the second sleeve 32 is in the first working state; when the second sleeve 32 is in the second working state, the lug 311 is disposed in the second groove 322 and is kept axially relatively stationary with respect to the second sleeve 32. Here, "the lug 311 matches the first groove 321 and the second groove 322" means that the shape and number of the lug should match the shape and number of the first groove and the second groove, so that the lug can freely move in the first groove along the axial direction and can be accommodated in the second groove. Preferably, the lugs are of identical shape and are equally spaced on the outer wall of the first sleeve. The axial length of the lug is slightly smaller than the axial width of the second groove, so that the lug can be conveniently matched with the side wall of the second groove to bear axial pressure.

As shown in fig. 2, the first sleeve 31 has an internal thread on its inner wall to form a threaded engagement with the threaded shaft. Under the action of the alternating magnetic field, the first sleeve 31 can be driven to rotate relative to the threaded shaft 20 under the action of the alternating magnetic field so as to move in the axial direction. The thread is preferably designed as a coarse thread or a trapezoidal thread to meet the thread fit requirement of having a certain axial bearing force and relatively small resistance in the axial thread movement.

As shown in fig. 4, when the alternating magnetic field rotates, the second sleeve 32 rotates counterclockwise under the magnetic force between the permanent magnet and the alternating magnetic field, and at this time, if the lug 311 is located at the position shown by the solid line (the proximal end of the first groove 321), the lug 311 keeps contact with the left side of the first groove 321, so that the first sleeve 31 rotates along with the rotation of the second sleeve 32, and the rotation of the first sleeve 31 moves axially in cooperation with the threaded connection of the threaded shaft 20. After the first sleeve 31 has been moved to the same horizontal position in the first recess 321 as the dotted position, if further axial movement of the first sleeve 31 is required, the prosthesis continues to be exposed to the alternating magnetic field until the position of the first target in the first recess 321 is reached. If the first sleeve 31 reaches the position of the first target in the first recess 321, it is necessary to keep the first sleeve 31 and the second sleeve 32 axially relatively stationary. At this time, the rotation direction of the alternating magnetic field is changed, since the first sleeve 31 and the second sleeve 32 are no longer in contact relation, the first sleeve 31 is kept stationary relative to the housing 10, the second sleeve 32 alone rotates clockwise, and the lug 311 enters the second groove 322 until the second groove 322 is in contact with the right side of the first sleeve 31. At this point, the first sleeve 31 tends to move proximally under the drive of the second sleeve 32, but is stopped by the proximal sidewall of the second groove 322. Hereby it is achieved that the first sleeve 31 remains axially relatively stationary with respect to the second sleeve 32. In addition, in the prosthesis, an end of the second groove 322, which is far away from the first groove 321, has an elastic body 324, and the elastic body 324 exerts a radial force on the lug 311 to clamp the lug 311. The elastic body is generally formed by a small spring and a trapezoidal round head mechanical part. The round head pressure of the elastic body is utilized to press the lug, so that the lug 311 is prevented from being separated from the second groove 322 by an external interference force source under the abnormal extension condition.

The second sleeve is configured to be rotatable about a second sleeve axis; under the action of an alternating magnetic field, the second sleeve rotates clockwise around the axis of the second sleeve, and when the first sleeve is driven to move axially and distally, the second groove is arranged on the left side of the first groove; under the action of the alternating magnetic field, the second sleeve rotates anticlockwise around the axis of the second sleeve, and when the first sleeve is driven to move axially and distally, the second groove is arranged on the right side of the first groove.

In this embodiment, the threaded shaft 20 is accommodated inside the first sleeve 31 and is threadedly coupled to the first sleeve 31. Further, the distal end of the threaded shaft 20 extends out of the first sleeve 31 and into the third sleeve 33. In order to move the first sleeve 31 axially, the threaded shaft 20 must be fixed relative to the housing 10. In particular, the threaded shaft is secured to the housing 10 by a latch. In this embodiment, the prosthesis further includes at least one first pin 41 and at least one fourth pin, the first pin 41 is fixed to the proximal end of the threaded shaft, and both ends of the first pin extend to be fixed to the housing 10, the fourth pin is fixed to the distal end of the threaded shaft 20, and both ends of the fourth pin extend through the third sleeve 33 and then are fixed to the housing 10, so that the threaded shaft 20 is fixed to the housing 10. Obviously, the third sleeve is provided with an axially extending groove at the junction of the fourth pin and the third sleeve, so as to facilitate the axial movement of the third sleeve. Preferably, the fourth pin extends through the rear of the fourth sleeve 34 and is fixedly connected to the housing 10, so that the fourth pin fixes the threaded shaft 20 and also fixedly connects the fourth sleeve 34 to the housing 10.

In this embodiment, the restricting member includes an end cap 80, a first thrust ball bearing 51, a second thrust ball bearing 52, and a third latch 43. The first thrust ball bearing 51 and the second thrust ball bearing 52 are located at the distal end of the first sleeve 31. The end cap 80 is located at a distal end of the first and second

thrust ball bearings

51, 52 and is removably coupled to the first sleeve 31 to retain the first and second

thrust ball bearings

51, 52 axially relative to the first sleeve 31. The thrust ball bearing may be a one-way thrust ball bearing or a two-way thrust ball bearing. The end of the third sleeve 33 that is connected to the first sleeve 31 has an outer flange 331 that forms a flange-like structure. The outer flange 331 is located between the first thrust ball bearing 51 and the second thrust ball bearing 52. The outer wall of the third sleeve 33 has a fourth groove 332 extending axially, and the third bolt 43 passes through the fourth groove 332, and both ends of the third bolt extend to be fixedly connected with the housing. Thus, when the first sleeve 31 makes a rotational movement, the third sleeve 33 remains still; meanwhile, when the first sleeve 31 moves axially, the third sleeve 33 is driven by the first sleeve 31 to move axially. The person skilled in the art will find out that here also the third bolt 43 can fix said threaded shaft 20 at the same time. Therefore, from the viewpoint of simplifying the structure of the prosthesis, only one of the third pin 43 and the fourth pin may be selected. The distal end of the first sleeve 31 shown in fig. 5 is externally threaded. The end cap 80 is a cylinder. The inner cavity of the end cap 80 has an internal thread matching the external thread of the first sleeve 31. The distal end of the end cap 80 is provided with a stop to prevent the first thrust ball bearing 51 and the second thrust ball bearing 52 from moving axially. The baffle has a through hole to allow the third sleeve 33 to pass through. In another embodiment, the restraint includes an end cap 80, a two-way thrust ball bearing. The shaft ring of the bidirectional thrust ball bearing is fixedly connected with the third sleeve 33, and the rest is similar to the embodiment.

Further, at least a distal end of the third sleeve is prismatic in shape. The prosthesis further comprises a fifth sleeve 35, the fifth sleeve 35 being located at the distal end of the housing 10 and being fixedly connected to the housing 10, the fifth sleeve 35 having a first lumen, at least a portion of the first lumen having a shape matching the shape of the distal end of the third sleeve 33, to further limit the rotational movement of the third sleeve 33. In this embodiment, the prosthesis further comprises a plurality of second pins 42, the fifth sleeve is located at the distal end of the fourth sleeve, and a fifth groove (not shown) is provided between the outer wall of the fifth sleeve and the housing, and the fourth pins are inserted into the fifth groove to limit the fifth sleeve from rotating around the axis.

Finally, the prosthesis further comprises a shell cap 90, said shell cap 90 being located at the distal end of the outer shell and pressing against the fifth sleeve 35 to keep the second sleeve 32, the fourth sleeve 34 and the fifth sleeve 35 axially stationary relative to the outer shell 10; the housing cap 90 is detachably connected to the housing 10, such that the second, fourth and fifth sleeves are axially held stationary relative to the housing, and the housing cap 90 has a second inner cavity, such that the third sleeve 33 extends through the second inner cavity and towards the distal end of the housing cap 90. The specific structure of the housing cap 90 and the mating relationship with the housing 10 can be referred to the structure of the end cap 80 and the mating relationship of the end cap 80 with the first sleeve 31. The material of the housing 10 is polyetheretherketone material. The material of the shell is polyether-ether-ketone material which has good biocompatibility and chemical corrosion resistance.

In the present invention, under the action of the alternating magnetic field, the second sleeve has a first working state and a second working state, when the second sleeve is in the first working state, the second sleeve drives the first sleeve to move along the axial direction of the housing, and when the second sleeve is in the second working state, the second sleeve keeps the first sleeve relatively stationary relative to the second sleeve in the axial direction. The extension mechanism is simple in design and good in effect, and potential failure of a complex mechanism is avoided.

In a preferred embodiment of the present invention, the first recess 321 and the second recess 322 on the inner wall of the second sleeve 32 are configured such that the plurality of second recesses 322 are only located on the same side of the first recess 321, and when the second sleeve 32 is rotated clockwise or counterclockwise, two different engagements can be generated with the first sleeve 31, i.e., one is to make the first sleeve 31 advance rotationally, i.e., extend outward, and the other is to make the lug 311 on the first sleeve 31 be caught in the second recess 322 and be relatively stationary. The two different matching relations between the first groove 321 and the second groove 322 and the lug 311 also have an important function of protecting the thread matching between the first sleeve 31 and the threaded shaft 20, transferring the axial pressure to the matching relation between the lug 311 and the second groove 322, and preventing the damage of the axial pressure to the thread in practical application.

In a preferred embodiment of the present invention, the elastic pressure of the elastic body in the second groove 322 on the lug 311 is utilized to prevent the first sleeve 31 from rotating due to external interference in case of abnormal extension, thereby destroying the extension mechanism in the prosthesis.

In a preferred embodiment of the present invention, the first grooves 321 and the second grooves 322 are designed such that the center line distances between the adjacent second grooves 322 are equal, and this design can achieve precise elongation. Meanwhile, the first sleeve 31 and the threaded shaft 20 are in threaded fit, so that the extending speed in the extending process is uniform, the body of a patient is prevented from being injured by instant extension in practical application, and the novel extension sleeve is more humanized and reasonable in design.

In a preferred embodiment of the present invention, the polygonal outer wall of the third sleeve 33 is designed to satisfy the requirement of axial movement and effectively prevent rotation, so as to avoid the rotation from damaging the outer bone linking structure of the prosthesis, such as the femur embedding segment.

The prosthesis assembly extension process of the invention is as follows: first, the first sleeve 31 is screw-fitted to the threaded shaft 20, the first thrust ball bearing 51, the second thrust ball bearing 52, and the third sleeve 33 are fitted inside the end cap 80, and then the end cap 80 is screw-fitted to the first sleeve 31.

Secondly, the second sleeve 32 comprises a plurality of permanent magnets, which can be glued in the third groove 323 of the second sleeve by silicone, and it should be noted that the same magnetic pole of the permanent magnet should be in contact with the third groove 323.

Then, the third thrust ball bearing 53, the second sleeve 32, the fourth thrust ball bearing 54 and the fourth sleeve 34 are sequentially fitted into the housing 10, the first sleeve 31 assembled in the initial step is placed in the second sleeve 32 in such a manner that the lugs 311 are placed in the first grooves 321 of the second sleeve 32, and then is assembled into the housing 10, the proximal end of the threaded shaft 20 is abutted to the proximal end of the housing, the catching grooves of the proximal end portion of the threaded shaft 20 are aligned with the through holes of the bottom of the housing, the first pins 41 are inserted into the through holes to fix the threaded shaft 20, and the third pins 43 are fitted to the other end of the threaded shaft 20 while the first sleeve 31 is assembled, wherein the third pins 43 are passed through the fourth grooves 332 of the third sleeve 33.

Then, the fifth sleeve 35 is fitted over the third sleeve 33, the fifth groove formed between the outer surface of the fifth sleeve 35 and the housing 10 is inserted with the second latch 42, and finally the housing cap 90 is closed.

Two ends of the shell 10 should be connected with components for connecting the body, wherein the components for connecting the body mainly comprise a backbone and a hinge base, and the materials of the components are titanium alloy materials with good biocompatibility.

Finally, when the prosthesis implanted into the human body needs to be lengthened, the limb is placed at the center of the permanent magnet force source outside the body, the auxiliary visual observation through X-ray and the like is carried out, when the second sleeve 32 obtains a force in a rotating direction given by the force source, the first sleeve 31 rotates along with the second sleeve 32, so that the first sleeve 31 axially advances, the third sleeve 33 is further pushed to axially advance, and the prosthesis is lengthened; when the first sleeve 31 reaches the specified length through visual observation, the external permanent magnet source gives reverse force, the second sleeve 32 rotates reversely, the first sleeve 31 is static relative to the box body, the lug 311 of the first sleeve 31 moves relative to the second sleeve 32 into the second groove 322 of the second sleeve 32, the external force source is stopped after the lug 311 is contacted and clamped with the second groove 322, and the extension is finished.

The invention realizes the non-invasiveness of the prosthesis prolonging process and avoids the complication of the patient caused by the secondary operation or the cortical-implanted prosthesis. The invention realizes the accuracy of the extension of the prosthesis, the actual extension length of the existing extension prosthesis can not be reliably known, and the invention reasonably designs the prosthesis which can be extended and has the determined extension length each time by combining the actual requirement.

In summary, the above embodiments have been described in detail for different configurations of the prosthesis, and it is understood that the present invention includes, but is not limited to, the configurations listed in the above embodiments, and any modifications based on the configurations provided by the above embodiments are within the scope of the present invention. One skilled in the art can take the contents of the above embodiments to take a counter-measure.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. 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

1. A prosthesis comprising a housing, a first sleeve, a second sleeve and a third sleeve received in the housing, wherein:

the second sleeve is coaxially sleeved outside the first sleeve;

under the action of an alternating magnetic field, the second sleeve has a first working state and a second working state, when the second sleeve is in the first working state, the second sleeve drives the first sleeve to move along the axial direction of the shell, and when the second sleeve is in the second working state, the second sleeve keeps the first sleeve relatively static relative to the second sleeve in the axial direction;

the outer wall of the second sleeve is provided with a plurality of third grooves, and the third grooves contain permanent magnets and are used for acting with an alternating magnetic field generated by an external permanent magnet force source to obtain acting force for driving the second sleeve;

the second sleeve is arranged for rotation about a second sleeve axis;

when the second sleeve is in a second state, the second sleeve rotates around the axis of the second sleeve in the other direction under the action of the alternating magnetic field;

the outer wall of the first sleeve has a plurality of lugs and the inner wall of the second sleeve has a plurality of first grooves and a plurality of second grooves, wherein:

the lug is matched with the first groove and the second groove, so that when the second sleeve is in a first working state, the lug moves axially in the first groove; when the second sleeve is in the second working state, the lug is placed in the second groove and keeps axially and relatively static relative to the second groove.

2. The prosthesis of claim 1,

the second sleeve is configured for rotation about a second sleeve axis;

under the action of an alternating magnetic field, the second sleeve rotates clockwise around the axis of the second sleeve, and when the first sleeve is driven to move axially and distally, the second groove is arranged on the left side of the first groove;

under the action of the alternating magnetic field, the second sleeve rotates anticlockwise around the axis of the second sleeve, and when the first sleeve is driven to move axially and distally, the second groove is arranged on the right side of the first groove.

3. The prosthesis of claim 1 or 2, wherein an end of the second recess remote from the first recess has an elastomer for snap-fitting the lug.

4. The prosthesis of claim 1, further comprising a threaded shaft,

when the second sleeve is in the first working state, the second sleeve drives the first sleeve to rotate around the axis of the second sleeve so as to move along the axial direction.

5. The prosthesis of claim 4, wherein the distal end of the threaded shaft extends out of the first sleeve and into the third sleeve, the prosthesis further comprising at least one first pin secured to the proximal end of the threaded shaft and having ends extending to be secured to the housing, at least one fourth pin secured to the distal end of the threaded shaft and having ends extending through the third sleeve and being secured to the housing to secure the threaded shaft to the housing.

6. The prosthesis of claim 1, wherein the restriction assembly comprises an end cap, a first thrust ball bearing, a second thrust ball bearing, and a third latch,

7. The prosthesis of claim 1, wherein the restriction assembly comprises an end cap, a bi-directional thrust ball bearing, and a third latch,

8. A prosthesis as claimed in claim 6 or 7, in which at least the distal end of the third sleeve is prismatic in shape, the prosthesis further comprising a fifth sleeve received in the housing, the fifth sleeve being located at the distal end of the housing and being fixedly connected thereto, the fifth sleeve having a first lumen, at least part of the first lumen having a shape matching the shape of the distal end of the third sleeve to restrict rotation of the third sleeve.

9. The prosthesis of claim 8, further comprising a plurality of second pins, at least one axially extending fifth groove being provided between an outer wall of the fifth sleeve and the housing, the second pins being inserted into the fifth groove to limit rotation of the fifth sleeve about the axis.

10. The prosthesis of claim 1, further comprising a fourth sleeve, a third thrust ball bearing and a fourth thrust ball bearing,

the fourth sleeve is located to be received in the outer housing at a distal end of the second sleeve and is configured to remain axially relatively stationary with respect to the outer housing, the third thrust ball bearing is located between the second sleeve and the outer housing, and the fourth thrust ball bearing is located between the second sleeve and the fourth sleeve to effect the second sleeve remaining axially relatively stationary with respect to the outer housing and rotating about a second sleeve axis.

11. The prosthesis of claim 10, further comprising a fifth sleeve received in the housing and located distally of the fourth sleeve, a cap located distally of the housing in removable connection with the housing to axially retain the second, fourth and fifth sleeves stationary relative to the housing; the shell cap has a second lumen such that the third sleeve extends through the second lumen and toward the distal end of the shell cap.