CN107349032B

CN107349032B - Artificial prosthesis with mortise and tenon structure at long bone stem

Info

Publication number: CN107349032B
Application number: CN201710751694.6A
Authority: CN
Inventors: 胡永成; 张剑锋; 田东牧; 王磊
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-08-28
Filing date: 2017-08-28
Publication date: 2024-02-13
Anticipated expiration: 2037-08-28
Also published as: CN107349032A

Abstract

The invention relates to an artificial prosthesis with a mortise and tenon structure of a long bone stem, wherein a bulge surface I and a rectangular bulge I of a connecting part I of a proximal handle of the prosthesis are respectively inserted into a strip-shaped groove II and a rectangular notch II of a connecting part II of a distal handle of the prosthesis, a bulge surface II and a rectangular bulge II of the connecting part of the distal handle of the prosthesis are respectively inserted into the strip-shaped groove I and the rectangular notch I of the connecting part I of the proximal handle of the prosthesis, a semicircular groove I of the connecting part I of the proximal handle of the prosthesis and a semicircular groove II of the connecting part II of the distal handle of the prosthesis are butted to form a cylindrical counter bore, a tenon is inserted into the cylindrical counter bore at one end of the cylinder, and the connecting part I and the connecting part II are locked together by the tenon. The prosthesis is firm and reliable in fixation, the operation is simple and convenient, the operation time is shortened, the operation effect and efficiency are improved, and the operation complications are reduced. Can be widely applied to different defects of long bone diaphysis, the minimum osteotomy amount can reach 3.0cm, and provides the maximum opportunity for reserving normal bone tissues and joints as much as possible.

Description

Artificial prosthesis with mortise and tenon structure at long bone stem

Technical Field

The invention relates to an artificial prosthesis with a mortise and tenon structure of a long bone stem, which is suitable for the technical field of clinical reconstruction of bone stem defects of middle and long bones, in particular to a diaphysis artificial prosthesis for reconstruction of structural bone defects caused by primary or metastatic tumor resection limb protection of long bones of limbs including humerus, ulna, radius, femur, tibia and fibula, bone defects after severe trauma, severe osteomyelitis infection and other osteotomy operations.

Background

With the development of surgical diagnosis and treatment technology, innovation of imaging technology and wide application of new auxiliary chemotherapy technology in perioperative period, limb and joint protection surgery has become the main trend and direction of bone tumor treatment at present; at the same time, structural bone defects caused by severe trauma, infection and the like also need to be reconstructed to restore limb function. Bone tumors can occur in theory at various positions, and long bones of limbs are one of the metastasis positions common in late stage of malignant tumors, and the design and the use method of the prosthesis are different according to the different occurrence positions. Current prosthetic applications focus mainly on larger joints with loads such as knee, hip, etc., and other sites such as the diaphysis of the long bones of the extremities are less well studied. Since the pathological nature of bone tumors determines the extent of resection of the tumor bone and surrounding soft tissue must be sufficiently broad, tumor prosthesis designs are generally large. Bone tumor treatment is today under the high-speed development of multidisciplinary, the treatment level and technology have advanced, but the development of tumor prostheses is relatively lagged, and the current prosthesis design applied to the diaphysis of the long bones of limbs often requires the 'reconstruction' of the host bone of a patient in order to 'successfully put' the giant tumor prosthesis into the patient, and the giant tumor prosthesis is mostly adapted by adopting a method of cutting normal bone tissues around lesions or cutting adjacent joints. This approach of adapting the prosthesis with excessive osteotomies and even with the truncation of joints not affected by neoplastic lesions, significantly violates the purpose of using the prosthesis: the prosthesis should be adapted to the patient, rather than having the patient adapt to the prosthesis. And such "successful placement" often comes at a certain "cost": the prosthesis has the advantages that the complications such as loosening, surrounding osteolysis, fracture and the like are increased, the service life of the prosthesis is shortened, the probability of multiple operations is increased, the difficulty of the later prosthesis revision operation is increased and the like.

The current fixing mode for the limb long bone diaphysis insertion type reconstruction prosthesis in clinic mainly comprises two modes of bone cement fixation and biological fixation.

As shown in fig. 9 and 10, the bone cement fixing method is a common diaphysis artificial prosthesis, bone cement is injected into the diaphysis intramedullary in the distal and proximal diaphysis cavities during operation, then the distal and proximal handles are inserted, the prosthesis can obtain better stability after the bone cement is solidified, and the limb functions can be recovered in a short period after operation. The defects are that: the bone cement fixing mode has high failure rate of the long-term prosthesis and risk of even death due to bone cement diseases.

The failure mode is mainly represented by mechanical aseptic loosening, fracture, dislocation and the like, wherein the mechanical aseptic loosening problem is most prominent, and the incidence rate is reported to be up to 30.6% -42.7%; in addition, the bone cement fixing mode has the risk of bone cement diseases, namely a series of clinical symptoms including hypotension, arrhythmia, hypoxia, myocardial infarction, hemorrhage, asthma attack and the like caused by bone cement implantation, and the occurrence rate of sudden cardiac arrest in bone cement type total hip replacement surgery is reported to be 0.5-10% and the mortality rate is 0.6-1.0% according to literature.

The connection mode has the following defects:

the joint of the distal end handle and the proximal end handle of the prosthesis is overlapped, and then the distal end handle and the proximal end handle of the prosthesis can be firmly locked by at least 2 screws, and the joint is used for determining that the length of a reconstructed part of the prosthesis (namely the length of an intraoperative bone cut) cannot be smaller than 5cm, otherwise, the strength of the prosthesis is greatly reduced, the probability of breakage and dislocation of the prosthesis is greatly improved, so that the prosthesis is placed in the operation in order to be 'successful', at least more than 5cm of bone tissues need to be resected, and the bone tissues which are resected by the part are very important for some tumor patients, especially a part of tumors are close to the joint surface, joint prosthesis replacement is often needed to be performed by resecting joints, so that for some tumor patients with lighter ages, longer expected survival time, whether the preservation of the joint is greatly affected by the affected limb functions of the patient is greatly, and meanwhile, the survival time of the residual bone tissues is faster, the service life of the prosthesis is long, the operation difficulty of the surgery can be reduced, and the quality of the prosthesis is very stable for the operation and the bone is resected by the normal operation. In cases of bone defects of the long bones of limbs caused by severe wounds, infections and the like, there is also the occurrence of cases where normal bones, even joints and the like must be resected excessively in order to place a large prosthesis, which can solve the problem in front of eyes, but the functions of limbs and the service life of the prosthesis must be greatly affected by resecting excessive bones or joints.

In addition, the overlapping connection structure is adopted, repeated involution is often needed in the operation, long-time holding is needed after successful involution, so that the connection parts of the near-end handle and the far-end handle of the prosthesis are prevented from shifting and falling off, the far-end handle and the near-end handle of the prosthesis are fixedly locked by screwing in 2 screws until the concentricity of the two connection parts is difficult to grasp, and the involution and the reset operation in the operation is complicated.

Although the initial stability is much worse than the effect of bone cement fixation by adopting a biological fixation mode, the biological fixation mode is accepted by patients and doctors more and more because the biological fixation prosthesis has good osteoinductive property and osseointegration property, can effectively improve the middle and long-term stability of the prosthesis, prolong the service life of the prosthesis and reduce the related mechanical complications of the prosthesis, and is one of the hot spots and directions of the current research.

Disclosure of Invention

In view of the state of the art and the defects existing in the prior art, the invention provides an artificial prosthesis with a long bone stem mortise and tenon structure, wherein a metal coating (such as a titanium coating) is adopted on the surfaces of a handle part of a proximal handle of the prosthesis and a handle part of a distal handle of the prosthesis for biological fixation, so that the artificial prosthesis has good osteoinductive property and osseointegrative property. The structure can bear larger load by adopting a traditional Chinese wood structure connecting mode, namely a mortise and tenon structure, and the far-end prosthesis handles and the near-end prosthesis handles are mutually meshed through exquisite bulge and groove designs, so that the tenon is inserted to achieve the effect of fixing the locked far-end handles and the near-end handles, and the movement or dislocation of the far-end prosthesis handles and the near-end prosthesis handles is effectively limited. The prosthesis is a more suitable treatment scheme for protecting limbs and joints of patients with limb long bone diaphysis tumor.

The invention adopts the technical proposal for realizing the aim that: an artificial prosthesis with a mortise and tenon structure at a long bone stem part comprises a proximal handle and a distal handle of the prosthesis; the handle part I of the prosthesis proximal end handle and the handle part II of the distal end handle are both cylinders, and the tail end I of the prosthesis proximal end handle and the tail end II of the distal end handle are hemispheres, and are characterized in that: the novel handle comprises a handle I and a handle II, and is characterized by further comprising tenons, wherein a rough metal coating is arranged on the surfaces of the handle I and the handle II;

the connecting part I of the proximal handle and the connecting part II of the distal handle of the prosthesis are mirror symmetry structures and are irregular shapes formed by combining a short semi-cylinder and a high semi-cylinder;

the connecting part I is provided with a strip-shaped groove I between the short semi-cylinder and the high semi-cylinder, a rectangular opening I communicated with the plane of the short semi-cylinder is arranged in the middle of the outer circle of the short semi-cylinder, a semicircular groove I is arranged on the plane of the high semi-cylinder, the notch at two ends of the semicircular groove I is larger than the semicircular groove to form a semicircular table I, the surface connected with the plane on the end face of the high semi-cylinder is a convex surface I, the semicircular surface connected with the convex surface I is a sinking surface, and a rectangular protrusion I is arranged on the semicircular sinking surface;

one end of the tenon is a tenon cap, the other end of the tenon is a cylinder, a round hole communicated with the cylinder is formed in the center of the tenon cap, four pins are arranged at intervals at the upper end of the tenon cylinder, and barbs are arranged at the upper end of each pin;

the connecting part I of the prosthesis proximal handle and the connecting part II of the prosthesis distal handle are butted together to form a cylinder, a bulge surface I and a rectangular bulge I of the connecting part I of the prosthesis proximal handle are respectively inserted into a strip groove II and a rectangular notch II of the connecting part II of the prosthesis distal handle, a bulge surface II and a rectangular bulge II of the connecting part II of the prosthesis distal handle are respectively inserted into a strip groove I and a rectangular notch I of the connecting part I of the prosthesis proximal handle, a semicircular groove I of the connecting part I of the prosthesis proximal handle and a semicircular groove II of the connecting part II of the prosthesis distal handle are butted together to form a cylindrical counter bore, a tenon is inserted into a cylindrical counter bore at one end of the cylinder, a tenon cap is arranged on a circle of counter seat in the cylindrical counter bore, the tenon cap and the cylinder form a surface, barbs on four pins of the tenon are respectively clamped on a circle of counter seat in the cylindrical counter bore at the other end, and the connecting part I and the connecting part II are locked together.

The beneficial effects of the invention are as follows: the artificial prosthesis for the diaphysis reconstruction fully considers the use of different bone defects of the long bone stem parts of limbs, especially the situation that the bone quantity defect is less (< 4 cm) or is closer to the joint surface, can cut off normal bone tissues as little as possible, keep normal joints which are not affected by tumor lesions as much as possible, adopts metal coating (such as titanium coating) to biologically fix the handle part of the proximal handle of the prosthesis and the handle part surface of the distal handle of the prosthesis, has better osteoinductive property and osseointegration, achieves good biological fixing effect by tight press fit in the proximal and distal marrow cavities of the prosthesis when the proximal and distal ends of the prosthesis are inserted, improves the middle and long-term stability of the prosthesis, prolongs the service life of the prosthesis and reduces the related mechanical complications of the prosthesis.

The designed diaphysis artificial prosthesis adopts a more reasonable biological fixation combined fixation mode with auxiliary fixation by combining steel plate screws, and the two fixation modes are combined to play roles of supplementing each other and supplementing each other. Although the initial stability of the biological fixation mode is poorer than that of the bone cement fixation, the stability of the biological fixation mode is gradually improved along with the bone ingrowth degree in the later period, wherein the long-term stability is obviously better than the bone cement fixation effect, the long-term complications of the biological fixation prosthesis are fewer, the service life is long, and the revision operation is easy. The initial stability of the prosthesis is greatly improved by combining the auxiliary fixation of the steel plate and the screw, and the defect of poor initial stability of biological fixation is overcome.

The structure design of the connecting part I of the prosthesis proximal handle and the connecting part II of the distal handle and the mutual engagement of the connecting part II have the interlocking effect, the operation is very fast and simple when the prosthesis proximal and distal handles are reset, the defect that the prosthesis in the prior art needs to be repeatedly folded when the prosthesis is reset and the prosthesis needs to be held for a long time when screws are screwed in to prevent the prosthesis proximal and distal displacement is avoided, the concentricity problem of the connecting part I of the prosthesis proximal handle and the connecting part II of the distal handle is well guaranteed, and the functions of good limitation, fixation, rotation prevention and drop prevention are achieved. The structural design of the tenon four-foot barbed structure has good anti-falling effect, is convenient to install, and prevents the situations of loosening, dislocation and the like after the connection of the proximal handle connecting part I and the distal handle connecting part II of the prosthesis. The connecting parts of the near and far end prostheses adopt mortise and tenon type structures, and the tenon is additionally used for locking, so that the whole fixing effect is firm and reliable.

The artificial prosthesis for the long bone stem part is designed, so that the operation time is greatly shortened, the bleeding amount in operation and the radiation exposure in operation are reduced, the operation efficiency and effect are improved, and the operation difficulty is reduced. The proximal and distal handles of the prosthesis are designed individually, so that the individuation prosthesis not only can improve the accuracy of the operation, but also can improve the treatment effect of the prosthesis after the operation. The tumor position, the size and the bone marrow cavity inner diameter obtained by measuring the imaging data of the patient are subjected to individuation design before operation, specific anatomical structures of pathological change bone tissues of each patient are subjected to individuation customization, the accuracy of operation and the treatment effect of the postoperative prosthesis are improved, the bleeding amount in operation and the exposure of radiation in operation are reduced, the complication of operation is reduced, the striking of the operation to the patient is lightened, and the safety of the operation is improved.

The artificial prosthesis of diaphysis designed to adopt the connection mode of mortise and tenon joint structure, which can shorten the reconstruction part of the prosthesis to 3cm without reducing the strength of the prosthesis, is especially suitable for tumor patients with smaller size (< 4 cm) or tumor patients with smaller distance to the joint surface, can reduce unnecessary excision of normal bone tissues and keep joints which are not affected by pathological changes as much as possible, because the more residual bone tissues remain, the faster the function of the affected limb is recovered, and the service life of the prosthesis is longer. Especially for the tumor patients with lighter ages and longer expected survival time, the joint protection operation can reduce the disability rate of the patients and restore the limb functions of the patients to the maximum extent.

In summary, the prosthesis of the present invention overcomes a series of drawbacks of the current prior art designs of reconstructive diaphyseal prostheses of long bones: 1. the bone grafting instrument can be widely applied to different defect conditions of long bone diaphysis, the minimum bone cutting amount can reach 3.0cm, the maximum bone cutting amount can reach all diaphysis, and the maximum opportunity is provided for reserving normal bone tissues and normal joints as much as possible; 2. the adoption of the mode of biological fixation combined with the auxiliary fixation of the steel plate screw not only ensures that the prosthesis has good initial stability, but also improves the middle and long-term stability of the prosthesis, reduces the incidence rate of middle and long-term complications of the prosthesis, prolongs the service life of the prosthesis and reduces the difficulty of secondary repair operation; 3. the prosthesis adopts an individual design, so that the operation difficulty is reduced, and the operation accuracy and the postoperative treatment effect are improved; 4. the prosthesis has the advantages of exquisite design, firm and reliable fixation, simple and convenient operation, greatly shortened operation time, improved operation effect and efficiency and reduced operation complications.

Drawings

FIG. 1 is a front view of the present invention;

FIG. 2 is a left side view of the present invention;

FIG. 3 is a right side view of the present invention;

FIG. 4 is an exploded view of the present invention in a front view position;

FIG. 5 is an exploded schematic view of the present invention in a side view position;

FIG. 6 is a schematic view of the structure of the distal handle of the present invention;

FIG. 7 is a schematic view of the structure of the tenon of the present invention;

FIG. 8 is a top view of FIG. 7;

FIG. 9 is a front view of a prior art prosthesis;

fig. 10 is a side view of a prior art prosthesis.

Detailed Description

For a better understanding of the technical solution of the present invention, the following description of the specific embodiments of the present invention is provided with reference to the accompanying drawings:

as shown in fig. 1 to 8, an artificial prosthesis with a mortise and tenon structure of a long bone stem part comprises a proximal handle 1, a distal handle 2 and a tenon 3 of the prosthesis.

The handle I1-1 of the proximal handle 1 and the handle II 2-1 of the distal handle 2 of the prosthesis are both cylinders, and the tail end I1-3 of the proximal handle 1 and the tail end II 2-3 of the distal handle 2 of the prosthesis are both hemispheres.

A rough metal coating layer 4 is arranged on the surfaces of the handle I1-1 and the handle II 2-1.

The connecting part I1-2 of the proximal handle 1 and the connecting part II 2-2 of the distal handle 2 of the prosthesis are mirror symmetry structures, and are irregular shapes formed by combining a short semi-cylinder and a high semi-cylinder.

A strip-shaped groove I1-2-1 is arranged between the short semi-cylinder and the high semi-cylinder of the connecting part I1-2, a rectangular notch I1-2-2 communicated with the plane of the short semi-cylinder is arranged in the middle of the outer circle surface of the short semi-cylinder, a semicircular groove I1-2-3 is arranged on the plane of the high semi-cylinder, the notch at the two ends of the semicircular groove I1-2-3 is larger than the semicircular groove to form a semicircular table I1-2-4, the surface connected with the plane on the end surface of the high semi-cylinder is a convex surface I1-2-5, the semicircular surface connected with the convex surface I1-2-5 is a sinking surface, and a rectangular convex I1-2-6 is arranged on the semicircular sinking surface.

A strip-shaped groove II 2-2-1 is arranged between the short semi-cylinder and the high semi-cylinder of the connecting part II 2-2, a rectangular notch II 2-2-2 communicated with the plane of the short semi-cylinder is arranged in the middle of the outer circle surface of the short semi-cylinder, a semicircular groove II 2-2-3 is arranged on the plane of the high semi-cylinder, the notch at the two ends of the semicircular groove II 2-2-3 is larger than the semicircular groove to form a semicircular table II 2-2-4, the surface connected with the plane on the end surface of the high semi-cylinder is a convex surface II 2-2-5, the semicircular surface connected with the convex surface II 2-2-5 is a sinking surface, and a rectangular convex II 2-2-6 is arranged on the semicircular sinking surface.

One end of the tenon 3 is a tenon cap 3-1, the other end is a column body, a round hole 3-4 communicated with the column body is arranged in the center of the tenon cap 3-1, four pins 3-2 are arranged at intervals on the upper end of the tenon 3 column body, and barbs 3-3 are arranged on the upper end of each pin 3-2.

The connecting part I1-2 of the proximal prosthesis handle 1 and the connecting part II 2-2 of the distal prosthesis handle 2 are butted together to form a cylinder, one convex surface I1-2-5 and one rectangular convex surface I1-2-6 of the connecting part I1-2 of the proximal prosthesis handle 1 are respectively inserted into the strip groove II 2-2-1 and the rectangular notch II 2-2 of the connecting part II 2-2 of the distal prosthesis handle 2, one convex surface II 2-2-5 and one rectangular convex surface II 2-2-6 of the connecting part 2-2 of the distal prosthesis handle 2 are respectively inserted into the strip groove I1-2-1 and the rectangular notch I1-2-2 of the connecting part I1-2 of the proximal prosthesis handle 1, one semicircular groove I1-2-3 and one semicircular groove II 2-3 of the connecting part II 2-2 of the distal prosthesis handle 2 are butted to form a counter bore, and two ends I-2-4 of the semicircular platform I-2-4 are respectively formed at two ends of the semicircular platform I-2-2.

The tenon 3 is inserted into a cylindrical counter bore at any end of the cylinder, a tenon cap 3-1 of the tenon 3 is arranged on a circle of table in the cylindrical counter bore, the tenon cap 3-1 and the cylinder form a surface,

barbs 3-3 on four feet 3-2 of the tenon 3 are respectively clamped on a circle of tables in the cylindrical counter bore at the other end, and the tenon 3 locks the connecting part I1-2 and the connecting part II 2-2 together.

The metal coating 4 is a titanium coating.

The length of the handle part I1-1 of the proximal handle 1 and the length of the handle part II 2-1 of the distal handle 2 of the prosthesis are designed and manufactured based on the position and the size of imaging tumor of a patient before operation, and the diameter is designed and manufactured based on the inner diameters of the bone marrow cavities of the proximal end and the distal end.

The length of the connecting part I1-2 and the connecting part II 2-2 after butt joint occlusion is the shortest of 3cm, the length is designed and manufactured based on the range of the preoperative patient imaging tumor section bone, and the diameter is designed and manufactured based on the diameter of the long bone at the position where the tumor is located.

The application method of the artificial prosthesis for reconstructing the diaphysis of the long bones of the limbs comprises the following steps:

the prosthesis is suitable for the operation treatment of the reconstruction of the prosthesis in the bone defect caused by tumors, wounds, infection and the like of the diaphysis of the limbs, particularly suitable for the tumor patients with small bone stems of the limbs, namely <4cm, or the tumor patients with the short distance from the joint surface, and can better keep joints which are not affected by the pathological changes.

Taking humeral stem tumor as an example, the prosthesis is customized individually according to the specific part and the size of the diseased bone tissue of the patient before operation, and the individually customized prosthesis can not only improve the accuracy of the operation, but also improve the treatment effect of the prosthesis after operation.

Firstly, after the bone and tissue invaded by humeral diaphysis tumor are resected, a marrow expanding device (a marrow expanding drill) is used for expanding marrow cavities in the proximal and distal end marrow cavities of residual humerus, after marrow expansion, a handle part I1-1 of a proximal handle 1 of the prosthesis is inserted into the proximal end marrow cavity of the humerus and is subjected to pressure matching biological fixation, a handle part II 2-1 of a distal handle 2 of the prosthesis is inserted into the distal end marrow cavity of the humerus and is subjected to pressure matching biological fixation, the biological fixation mode can effectively improve the stability of the prosthesis in the middle and long term, the service life of the prosthesis is prolonged, mechanical complications such as loosening, dislocation, bone dissolution around the prosthesis, fracture and the like are reduced, after the proximal and distal prostheses are firmly placed, a connecting part I1-2 of the proximal handle 1 of the prosthesis and a connecting part II 2 of the distal handle 2 of the prosthesis are subjected to matching, and after the matching is successful, the prosthesis is inserted into a cylindrical countersunk hole by a head 3, and the prosthesis is successfully installed at the moment. The length of the joint I1-2 of the proximal prosthesis handle 1 and the joint II 2-2 of the distal prosthesis handle 2 after successful combination (namely the length of the bone defect after the resection of the tumor bone) can be as low as 3cm, and the longest can be the full diaphysis length. In order to improve the initial stability of the prosthesis, auxiliary steel plates and screws can be added on the outer side of the prosthesis to be respectively fixed on the residual proximal and distal diaphysis, and the screws are fixed by adopting single skin. After the steel plate and the screw are fixed successfully, the passive movable affected limb checks whether the prosthesis is loose or not, dislocation and the like.

While the preferred embodiment of the present invention has been described in detail, the invention is not limited to the embodiment, and those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the invention, and the equivalent modifications or substitutions are included in the scope of the present invention as defined in the appended claims.

Claims

1. An artificial prosthesis with a mortise and tenon structure at a long bone stem part comprises a proximal handle (1) and a distal handle (2) of the prosthesis; the handle part I (1-1) of the prosthesis proximal handle (1) and the handle part II (2-1) of the distal handle (2) are both cylinders, and the tail end I (1-3) of the prosthesis proximal handle (1) and the tail end II (2-3) of the distal handle (2) are hemispheres, and are characterized in that: the novel handle comprises a handle I (1-1) and a handle II (2-1), and also comprises a tenon (3), wherein a rough metal coating (4) is arranged on the surfaces of the handle I (1-1) and the handle II (2-1);

the connecting part I (1-2) of the prosthesis proximal handle (1) and the connecting part II (2-2) of the prosthesis distal handle (2) are mirror symmetry structures, and are irregular shapes formed by combining a short semi-cylinder and a high semi-cylinder;

a strip-shaped groove I (1-2-1) is arranged between the short semi-cylinder and the high semi-cylinder of the connecting part I (1-2), a rectangular notch I (1-2-2) communicated with the plane of the short semi-cylinder is arranged in the middle of the outer circle surface of the short semi-cylinder, a semicircular groove I (1-2-3) is arranged on the plane of the high semi-cylinder, the notch at two ends of the semicircular groove I (1-2-3) is larger than the semicircular groove to form a semicircular table I (1-2-4), the surface connected with the plane on the end surface of the high semi-cylinder is a raised surface I (1-2-5), the semicircular surface connected with the raised surface I (1-2-5) is a sinking surface, and a rectangular raised surface I (1-2-6) is arranged on the semicircular sinking surface;

one end of the tenon (3) is a tenon cap (3-1), the other end of the tenon is a column body, a round hole (3-4) communicated with the column body is formed in the center of the tenon cap (3-1), four pins (3-2) are arranged at intervals at the upper end of the tenon (3) column body, and barbs (3-3) are arranged at the upper end of each pin (3-2);

the connecting part I (1-2) of the prosthesis proximal handle (1) and the connecting part II (2-2) of the prosthesis distal handle (2) are butted together to form a cylinder, one convex surface I (1-2-5) and one rectangular convex surface I (1-2-6) of the connecting part I (1-2) of the prosthesis proximal handle (1) are respectively inserted into a strip-shaped groove II (2-2-1) and a rectangular notch II (2-2) of the connecting part II (2-2) of the prosthesis distal handle (2), one convex surface II (2-2-5) and one rectangular convex surface II (2-2-6) of the connecting part II (2-2) of the prosthesis distal handle (2) are respectively inserted into the strip-shaped groove I (1-2-1) and the rectangular notch I (1-2-2) of the prosthesis proximal handle (1), one semi-cylindrical groove I (1-2-2) of the connecting part I (1-2) of the prosthesis proximal handle (1) is respectively inserted into a counter bore hole II (2-3) of the cylinder, the tenon cap (3-1) of the tenon (3) is arranged on a circle of table in the cylindrical counter bore, the tenon cap (3-1) and the cylinder form a surface, barbs (3-3) on four feet (3-2) of the tenon (3) are respectively clamped on a circle of table in the cylindrical counter bore at the other end, and the tenon (3) locks the connecting part I (1-2) and the connecting part II (2-2) together; the length of the connecting part I (1-2) and the connecting part II (2-2) after butt joint and occlusion is 3cm at the shortest; the metal coating (4) is a titanium coating.