CN214017997U - Expansible prosthesis for reconstruction of cancellous bone - Google Patents

Abstract

The utility model discloses an expandable prosthesis for reconstruction of cancellous bone, which comprises a ring-shaped main body and a one-way expansion component; a gap is formed on the side wall of the main body; the unidirectional expansion assembly comprises a first expansion piece and a second expansion piece which are positioned in the main body and arranged on two sides of the gap, and a unidirectional limiting structure which is arranged between the first expansion piece and the second expansion piece and limits the relative movement of the first expansion piece and the second expansion piece to relative back-to-back movement; the one-way expansion component of the utility model enables the ring-shaped main body to be expanded by one-way expansion, and the outer surface of the main body is in press fit with the medullary cavity, thereby the prosthesis is pressed and fixed in the medullary cavity of the femur, and bone ingrowth can be obtained in a long term; the porous structure is formed on the surface of the main body, so that the reconstruction prosthesis can obtain a long-term biological fixation foundation, the fixation strength of the long-term femur-reconstruction prosthesis is improved, the risk of fracture around the long-term prosthesis is reduced, the initial fixation effect of the bone cement femoral stem is improved, and the success rate of the revision of the bone cement femoral prosthesis is improved.

Description

Expansible prosthesis for reconstruction of cancellous bone

Technical Field

The utility model relates to an expansible metal ring-shaped prosthesis for reconstruction of cancellous bone, belonging to the field of medical instruments.

Background

Artificial hip replacement is an effective means for treating various terminal coxitis. Artificial hip arthroplasty is a procedure to treat various artificial hip replacement failures. Due to severe osteolysis, stress shielding, infection around the prosthesis, multiple surgical history, osteoporosis, iatrogenic bone defects caused by perforation or windowing when the original prosthesis or residual bone cement is taken out and the like caused by loosening or abrasion, the femur side is often subjected to bone defects of different degrees in the artificial hip revision surgery. The difficulty in reconstruction is that there is often a severe bone defect on the femoral side, and the femur often incorporates proximal anatomical remodeling during revision, such as varus or retroversion remodeling. Thus, the femoral side bone defect reconstruction strategy is determined based on the severity of the bone defect, the amount and quality of bone remaining, and anatomical remodeling changes.

Many scholars have proposed the typing of femoral side bone defects, the most widely used type being the Paprosky type, which takes into account the three factors of bone defect site (metaphysis or diaphysis), residual bone mass and support of the proximal femur, and the length of the isthmus of the shaft available for distal fixation. The physician can objectively assess the femoral bone defect based on the typing and select an appropriate reconstruction method based on the defect typing. For severe femoral bone defects, particularly for bone defects caused by the fact that a medullary cavity forms a horn-shaped structure expanding downwards or the medullary cavity of the femur expands to form a chimney-pipe shape (chimney-pipe shape), a bone-free stem isthmus is used for fixing a femoral stem, and at present, traditional reconstruction methods such as assembling a conical ridged titanium stem, pressing bone grafting, proximal femoral allograft bone-prosthesis compound and proximal femoral replacement can be selected. The incidence of early prosthesis subsidence after the operation of assembling the conical titanium handle with the ridge is higher, the risk of fracture in the operation or after the operation is increased, and a series of complications such as stress concentration, stress shielding, insufficient effective fixed length, unstable prosthesis fixation and the like can be caused. Proximal femoral allograft bone-prosthesis composites present potential risks of disease transmission, resorption and nonunion of the graft, aseptic loosening, periprosthetic fractures and infection. The proximal femoral replacement dislocation rate is high and the long-term survival rate is low, and is only suitable for treating the elderly patients with low activity and a great deal of serious bone defects. The pressing bone grafting has the potential of reconstructing the bone mass of a patient in theory, but has the defects of higher risks of fracture in operation, postoperative prosthesis sinking and the like, higher technical requirements of the operation, time consumption, risk of disease transmission, bone grafting absorption and the like.

Disclosure of Invention

In view of the above problems, the present invention provides an expandable metal ring prosthesis for reconstruction of cancellous bone, which overcomes the problems of the prior art, enhances the micro-hinge lock capability of bone cement in the hardened medullary cavity, and improves the stability of the bone cement prosthesis.

In order to achieve the above purpose, the utility model adopts the following technical scheme: an expandable prosthesis for cancellous bone reconstruction comprising a ring-shaped body and a unidirectional expansion member; a gap is formed on the side wall of the main body; the unidirectional expansion assembly comprises a first expansion piece and a second expansion piece which are positioned in the main body and arranged on two sides of the gap, and a unidirectional limiting structure which is formed between the first expansion piece and the second expansion piece and limits the relative movement of the first expansion piece and the second expansion piece to be relatively back-to-back movement is formed.

In some embodiments, the first and second expansion members are respectively a first one-way tooth and a second one-way tooth, the first one-way tooth is formed on the main body on one side of the gap, each tooth tip portion on the first one-way tooth points to the gap, the second one-way tooth is fixed on the main body on the other side of the gap, each tooth tip portion on the second one-way tooth deviates from the gap, and the teeth on the second one-way tooth and the teeth on the first one-way tooth are engaged to form a one-way limiting structure.

In some embodiments, the body includes first and second arcuate bodies hingedly connected to one another, the side faces of the first and second arcuate bodies forming the gap therebetween.

In some embodiments, the body has a porous structure formed on a surface thereof; the body has a solid layer inside.

In some embodiments, the porous structure is a trabecular bone-like porous structure with a pore size of 800 μm ± 200 μm and a porosity of 50% to 80%.

In some embodiments, the inner surface of the body is hollow tubular with an inner diameter of 0.8cm to 6cm, the cross section of the outer surface of the body is circular or elliptical, the section of the coronal surface of the body is rectangular or trapezoidal, the height of the body is 1cm to 10cm, and the thickness of the body is 1mm to 20 mm.

In some embodiments, the main body is formed by 3D printing, and the material is titanium alloy or tantalum metal.

The utility model adopts the above technical scheme, it has following advantage: the utility model provides an expansible prosthesis for reconstructing cancellous bone, which comprises a ring-shaped main body and a one-way expansion component; a gap is formed on the side wall of the main body; the unidirectional expansion assembly comprises a first expansion piece, a second expansion piece and a unidirectional limiting structure which is arranged between the first expansion piece and the second expansion piece and limits the relative movement of the first expansion piece and the second expansion piece to be relatively back-to-back movement; the unidirectional expansion component enables the ring-shaped main body to be expanded in a unidirectional expansion mode, the outer surface of the main body is in compression fit with the medullary cavity, and therefore the prosthesis is pressed and fixed in the medullary cavity of the femur, and bone ingrowth can be achieved in a long term; in addition, a porous structure is formed on the surface of the main body, and the porous structure on the outer surface of the main body can obtain bone ingrowth, so that the reconstructed prosthesis can obtain a long-term biological fixation foundation, the fixation strength of the long-term femur-reconstructed prosthesis is improved, and the risk of fracture around the long-term prosthesis is reduced; in the porous structure of the internal surface of bone cement infiltration main part, bone cement forms little twistlock between the internal surface of main part and bone cement femoral prosthesis, improves bone cement femoral stem initial fixation effect, improves the success rate that bone cement femoral prosthesis was renovated, the utility model discloses effectively overcome prior art's defect, improve bone cement prosthesis and rebuild the curative effect.

Drawings

Fig. 1 is a schematic structural diagram of the present invention;

FIG. 2 is another schematic structural view of the present invention;

fig. 3 is a schematic top view of the present invention;

fig. 4 is a schematic sectional structure of the present invention;

fig. 5 is a schematic structural view of the main body of the present invention.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the objects, features and advantages of the invention can be more clearly understood. It should be understood that the embodiments shown in the drawings are not intended as limitations on the scope of the invention, but are merely illustrative of the true spirit of the technical solution of the invention.

As shown in fig. 1 to 3, the present invention provides an expandable prosthesis for reconstruction of cancellous bone, which comprises a ring-shaped main body 1 and a one-way expansion assembly; a gap 2 is formed on the side wall of the main body 1; the unidirectional expansion component comprises a first expansion piece 3 and a second expansion piece 4 which are positioned in the main body 1 and arranged on two sides of the gap, and a unidirectional limiting structure which is formed between the first expansion piece 3 and the second expansion piece 4 and limits the relative movement of the two expansion pieces to be relatively back-to-back movement.

In the above embodiment, preferably, as shown in fig. 3 and 4, the first extender 3 and the second extender 4 are respectively a first unidirectional tooth and a second unidirectional tooth, the first unidirectional tooth is formed on the main body 1 on one side of the gap, each tooth tip portion on the first unidirectional tooth faces the gap, the second unidirectional tooth is fixed on the main body 1 on the other side of the gap, each tooth tip portion on the second unidirectional tooth faces away from the gap, and the teeth on the second unidirectional tooth and the teeth on the first unidirectional tooth are engaged to form a unidirectional limiting structure. When applying the first one-way tooth of external drive and the one-way tooth of second and moving in opposite directions, tooth on the first one-way tooth is tighter with the tooth interlock on the one-way tooth of second, the relative motion of first one-way tooth and second direction tooth is locked promptly, when applying the one-way tooth of external drive and moving in opposite directions of second, can be relative dorsad gliding motion between the tooth of first one-way tooth and the one-way tooth of second for the gap is strutted the grow, realize the expansibility of the surface of main part 1 promptly, guarantee the cooperation that compresses tightly between the surface of main part 1 and the femoral medullary intracavity wall, long-term can obtain the bone length and go into.

In the above embodiment, preferably, the width of the first unidirectional teeth and the second unidirectional teeth is 20% to 100% of the height of the body 1.

In the above embodiment, preferably, as shown in fig. 5, the main body 1 comprises a first arc-shaped body 11 and a second arc-shaped body 12 hinged to each other, and a gap 2 is formed between the side end faces of the first arc-shaped body 11 and the second arc-shaped body 12 to facilitate expansion of the prosthesis. It is to be understood that the structure of the body 1 is not limited thereto, and the body 1 itself may be moderately expanded.

In the above embodiment, preferably, the surface of the main body 1 is formed with a porous structure, the bone cement can penetrate into the porous structure of the inner surface of the main body 1, and the bone cement forms a micro-hinge lock between the inner surface of the main body 1 and the bone cement femoral prosthesis, so as to improve the initial fixing effect of the bone cement stem; the outer surface of the main body 1 is in compression fit with the inner wall of a femoral medullary cavity so as to obtain bone ingrowth in a long term; artificial bone or coating materials for promoting bone ingrowth can be sprayed in the porous structure on the outer surface, so that osseointegration is stimulated into the porous surface; alternatively, the porous structures on the inner and outer surfaces are filled with antibiotic drugs or antimicrobial materials or coatings for preventing periprosthetic infection or promoting bone ingrowth.

In the above embodiment, preferably, as shown in fig. 4, the body 1 has a solid layer 100 inside to prevent the bone cement from penetrating from the inner surface into the outer surface, avoiding the bone cement from affecting the bone ingrowth potential of the outer surface.

In the above embodiment, preferably, the porous structure is a trabecular bone-like porous structure, the pore diameter is 800 μm ± 200 μm, and the porosity is 50% -80%.

In the above embodiment, preferably, the inner surface of the main body 1 has a hollow tubular shape, the inner diameter is 0.8cm to 6cm, preferably 1cm to 2.5cm, the cross section of the outer surface of the main body 1 has a circular shape, an elliptical shape or other irregular shape so as to be adapted to the shape of the intramedullary canal, and when the cross section is circular, the diameter of the outer surface of the main body 1 is 1.2cm to 6.4cm, the section of the coronal surface of the main body 1 may have a rectangular shape or a trapezoidal shape, the height is 1cm to 10cm, preferably 1.2cm to 4cm, and the thickness is 1mm to 20mm, preferably 2mm to 6 mm.

In the above embodiment, the main body 1 may preferably be a hollow cylinder or a cone having a taper of 0 ° to 30 °, preferably 1 ° to 15 °.

In the above embodiment, preferably, the main body 1 is formed by 3D printing, and the material is a metal material, specifically, formed by electron beam melting or other 3D printing process, and the material is titanium alloy or tantalum metal.

Additionally, based on an expandable prosthesis for cancellous bone reconstruction in any of the above embodiments, the present invention also provides an implantation method for an expandable prosthesis for cancellous bone reconstruction, comprising the steps of:

1) acquiring CT (computed tomography) examination data of hip joints on the affected side and the healthy side of a patient before operation; reconstructing the femur morphology using a computer, selecting the expandable prosthesis of any of the above embodiments, or customizing the expandable prosthesis of any of the above embodiments according to patient-specific 3D printing;

2) performing preoperative planning according to the preoperative femur morphology;

3) exposing the femur to be reconstructed in an operation, performing reaming of a femoral medullary cavity, and filing the femoral medullary cavity to a preset size;

4) placing the expansible ring-shaped prosthesis into a preset position planned before an operation in a medullary cavity by using a special holder, inserting the expansible ring-shaped prosthesis into the expansible ring-shaped prosthesis by using a special dilator, and rotating the dilator to gradually prop the expansible ring-shaped prosthesis open until the expansible ring-shaped prosthesis is tightly pressed with the inner wall of the medullary cavity;

5) bone cement is poured into the medullary cavity to infiltrate the expandable prosthesis, and then the bone cement femoral stem is implanted.

The present invention has been described only with reference to the above embodiments, and the structure, arrangement position and connection of the components may be changed. On the basis of the technical scheme of the utility model, the all sides according to the utility model discloses the principle is all not excluded to the improvement that individual part goes on or the transform of equivalence the utility model discloses a protection scope is outside.

Claims (7)

1. An expandable prosthesis for reconstruction of cancellous bone, comprising: comprises a ring-shaped main body and a one-way expansion component; a gap is formed on the side wall of the main body; the unidirectional expansion assembly comprises a first expansion piece and a second expansion piece which are positioned in the main body and arranged on two sides of the gap, and a unidirectional limiting structure which is formed between the first expansion piece and the second expansion piece and limits the relative movement of the first expansion piece and the second expansion piece to be relatively back-to-back movement is formed.

2. An expandable prosthesis for use in cancellous bone reconstruction, as set forth in claim 1, wherein: first expansion piece and second expansion piece are first one-way tooth and the one-way tooth of second respectively, first one-way tooth form in gap one side in the main part, each tooth point portion on the first one-way tooth all points to the gap, the one-way tooth of second is fixed at the gap opposite side in the main part, each tooth point portion on the one-way tooth of second all deviates from the gap, tooth on the one-way tooth of second and the tooth on the one-way tooth of first interlock mutually the interlock constitute one-way limit structure.

3. An expandable prosthesis for use in reconstruction of cancellous bone, as claimed in claim 1 or 2, wherein: the main part includes first arc body and the second arc body of mutual articulated, form between the side end face of first arc body and second arc body the gap.

4. An expandable prosthesis for use in cancellous bone reconstruction, as set forth in claim 1, wherein: a porous structure is formed on the surface of each main body; the body has a solid layer inside.

5. An expandable prosthesis for use in cancellous bone reconstruction, as claimed in claim 4, wherein: the porous structure is a bone-like trabecula porous structure, the aperture is 800 microns +/-200 microns, and the porosity is 50-80%.

6. An expandable prosthesis for use in cancellous bone reconstruction, as set forth in claim 1, wherein: the inner surface of the main body is in a hollow tubular shape, the inner diameter is 0.8 cm-6 cm, the cross section of the outer surface of the main body is circular or elliptical, the section of the coronal surface of the main body is rectangular or trapezoidal, the height of the main body is 1 cm-10 cm, and the thickness of the main body is 1 mm-20 mm.

7. An expandable prosthesis for use in cancellous bone reconstruction, as set forth in claim 1, wherein: the main part adopts 3D to print the shaping, and the material is metal material.

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