Porous PEEK (Polyether Ether Ketone) prosthesis with marrow hole and assembled mortise and tenon joint structure for repairing humeral shaft bone defect

Abstract

The utility model relates to a porous PEEK (Polyether Ether Ketone) prosthesis with an assembled tenon-and-mortise structure, which is used for repairing humeral shaft bone defects and is provided with medullary holes. Comprising a porous PEEK prosthesis reconstruction part composed of two mortise and tenon joint structures which are mutually inserted and locked through a tenon, prosthesis handles with medullary holes are arranged at the two ends of the porous PEEK prosthesis reconstruction part respectively, and the medullary holes of the prosthesis handles are communicated with the porous PEEK prosthesis reconstruction part. The diaphysis prosthesis is large in aperture, high in porosity and high in communication rate, is provided with medullary holes, can promote ingrowth of prosthesis handles at the far end and the near end of the prosthesis and reconstruction section bones, enables a patient to move in an early stage, reduces complications, improves the living standard of the patient, achieves simultaneous ingrowth of the inside and the outside of the bone, promotes the ingrowth of the bone and blood vessels into internal pores, and improves the survival rate of the bone. Mechanical locking can be formed between the new bone growing into the pores and the prosthesis material, so that the bone defect repair time is shortened, and long-term stability is realized. The accurate connection of the tenon-and-mortise structure is simpler and faster, and the operation time is shortened.

Description

Technical Field

[0001] The utility model relates to a PEEK prosthesis, in particular to a porous PEEK prosthesis with a modular mortise and tenon structure and a medullary hole for repairing humeral shaft bone defects. Background Art

[0002] Humeral shaft bone defects are caused by high-energy trauma or bone tumors, severe bone infections, congenital pseudoarthrosis, fracture nonunion and other pathological diseases. Humeral shaft bone defects can not only cause secondary pathological and physiological changes in adjacent bones and joints, and even surrounding soft tissues, but also lead to residual organic or functional disorders of the limbs. If the bone defect is large and exceeds the body's regenerative capacity, it is difficult to regenerate naturally without the help of surgical treatments. Many cases of large bone defects often require multiple surgical interventions to restore limb function. How to reconstruct bone defects is still a challenge, although there are many methods for treating bone defects in clinical practice, such as bone transplantation (autologous or allogeneic), Ilizarov technique (distraction osteogenesis), Masquelet technique (membrane-induced osteogenesis) and prosthesis implantation. However, for the treatment of large humeral shaft bone defects, due to the long treatment cycle, high surgical difficulty, poor postoperative effect, high disability and deformity rate, etc., the treatment is still very difficult, which is a major problem that clinical orthopedic surgeons need to face. In the past, bone transplantation mainly used autologous bone (gold standard) and allogeneic bone as transplant materials, but it was difficult to fully meet clinical needs due to the limitations of donor site damage, insufficient sources and disease transmission. Bone transplantation is the most commonly used method in clinical practice and has achieved encouraging success in bone reconstruction. However, complications such as nonunion, refracture and infection are also common, especially in patients with tumors, who are at greater risk of complications due to radiotherapy and immunosuppressive chemotherapy. Although the Ilizarov technique is satisfactory for the treatment of limb metaphyseal defects, the limitations of specific surgical devices and complex surgical procedures may be significant drawbacks. After the Ilizarov technique, most patients have to endure persistent pain caused by the external fixator and long periods of non-weight-bearing. At the same time, complications are also frequently reported, including pseudoarthrosis, axial deviation, joint contracture or stiffness, pinhole infection or bone rupture. The Masquelet technique has been used in clinical practice for more than ten years. The operation is simple and effective with few complications. However, this technique requires at least two stages of surgery, and it is not suitable for patients with a short life span or who are receiving palliative care. Reconstructing the bone with a prosthesis has the advantages of early weight-bearing, early rehabilitation, and low infection rate, but there are few reports on this technology. In clinical practice, due to the lack of a suitable prosthesis, the adjacent joint needs to be removed, and bone lesions are often repaired by joint replacement rather than reconstruction. The preservation of the joint is crucial to the function of the affected limb, especially for young patients or elderly patients with a long life span. Therefore, artificial bone graft materials such as ceramics, metals, and polymers have been widely developed.

[0003] In 1982, Lempberg et al. first used a segmental diaphyseal prosthesis to reconstruct large segmental defects of the diaphyseal shaft after tumor resection of the limb long bones, and achieved good results. The segmental diaphyseal prosthesis consists of two or three parts, namely the distal and proximal prosthesis stems, the reconstruction segment, and bolts and nuts. When used, the distal and proximal prosthesis stems are inserted into the distal and proximal medullary cavities of the defective long bones, respectively, and fixed with bone cement. After the distal and proximal prosthesis stems are repositioned, they are fixed with bolts and nuts. Compared with other methods of repairing and reconstructing bone defects, the main advantages of this method are simple operation and short operation time, which is conducive to patients with poor physical conditions to tolerate surgical trauma; there is no problem of bone healing at the broken ends, and there is no need to worry about risks such as postoperative bone non-union, and it is also applicable to patients who need radiotherapy and chemotherapy after surgery; no bone grafting is required, so there will be no complications related to autologous bone or allogeneic bone transplantation; the prosthesis is firmly fixed, which can ensure the patient's early functional exercise after surgery, and is conducive to the early restoration of normal functional status of the affected limb; the reconstruction part of the prosthesis can be precisely customized according to the needs of the disease, which is especially suitable for the reconstruction of bone tumor cases that require precise resection of the lesion range, and can further reduce the local recurrence rate of the tumor. With the rapid development of surgical techniques and design manufacturing, the design of segmental diaphyseal prostheses is also constantly improving and optimizing. For example, improvements to the reconstruction part of the prosthesis have added an adjustable mechanism to the segmental diaphyseal prosthesis, which has better flexibility and applicability in the process of repairing bone defects of different lengths; improvements to the connection method have made the connection structure of the prosthesis more scientific and reasonable, and the intraoperative operation has become simpler, which has reduced related complications and saved surgical time; improvements to the fixation method have expanded the scope of use of segmental diaphyseal prostheses and improved the stability of the prosthesis and postoperative clinical efficacy. Although there are relatively few studies and reports on segmental diaphyseal prostheses at present, and the total number of clinical application cases is relatively small, the reliability and practicality of segmental diaphyseal prostheses have initially emerged. The vast majority of scholars hold a relatively positive attitude towards the clinical effect of segmental diaphyseal prosthesis reconstruction, and believe that the method of using segmental diaphyseal prostheses to reconstruct long bone defects has good clinical practicality and development prospects.

[0004] Although segmental diaphyseal prostheses are constantly being improved and optimized, the current prosthesis designs all adopt a solid design, ignoring the effect of bone marrow on the repair of bone defects and immune regulation. Existing studies have shown that bone marrow is an important tissue stored in the bone marrow cavity, which is mainly responsible for hematopoiesis and immune function. In the osteogenesis process, bone marrow also plays an important role. First, hematopoietic stem cells in the bone marrow can differentiate into osteoblasts, thereby participating in the formation and repair of bone tissue. Osteoblasts are a special type of cell that has the ability to secrete bone matrix and can promote the growth and regeneration of bone tissue. The differentiation and proliferation of osteoblasts are regulated by many factors, such as cytokines, growth factors, hormones, etc. In the bone marrow, the proliferation and differentiation of osteoblasts are regulated by hematopoietic stem cells and other cells, thereby ensuring the formation and repair of bone tissue; secondly, hematopoietic stem cells in the bone marrow can also secrete some cytokines, such as bone morphogenetic protein, fibroblast growth factor, etc. These factors can promote the proliferation and differentiation of osteoblasts, thereby promoting the growth and regeneration of bone tissue. In addition, hematopoietic stem cells in the bone marrow can also secrete some growth factors, such as platelet-derived growth factor, stromal cell growth factor, etc. These factors can promote the growth and repair of blood vessels, thereby providing sufficient nutrition and oxygen for bone tissue. In addition to hematopoietic stem cells and osteoblasts, there are also some immune cells in the bone marrow, such as macrophages, T lymphocytes, etc. These immune cells can participate in the formation and repair of bone tissue by secreting some cytokines and growth factors. For example, macrophages in the bone marrow can secrete some factors that promote the proliferation and differentiation of osteoblasts, such as interleukin-1, interleukin-6, etc.; while T lymphocytes can secrete some cytokines, such as transforming growth factor-β, interferon-γ, etc., which can promote the growth and repair of bone tissue. In short, the bone marrow has an important influence on the osteogenesis process. It can not only provide osteoblasts, but also secrete some cytokines and growth factors to promote the growth and repair of bone tissue. When the bone marrow is dysfunctional or damaged, it will affect the osteogenesis process, leading to the occurrence of bone diseases such as bone loss and osteoporosis. Therefore, based on the positive effect of bone marrow on osteogenesis, the present invention designs a medullary hole on the prosthesis, so that the bone prosthesis and the bone marrow cavity between the diaphysis can be connected, so as to exert the positive promoting effect of bone marrow on bone repair.

[0005] Furthermore, the current design of its fixation method has always been mainly based on bone cement fixation. The single bone cement fixation method is obviously no longer suitable for current treatment needs, and the high long-term loosening rate of bone cement fixed prostheses has been difficult to solve. Therefore, the single bone cement fixation method has become a major bottleneck restricting the development of segmental diaphyseal prostheses. Non-bone cement fixed prostheses use the principle of biological fixation to achieve bony integration between the prosthesis and the host bone, which can fundamentally solve the problem of long-term loosening of bone cement fixed prostheses. At present, there are many and in-depth studies on its fixation mechanism and effect. It is generally believed that the long-term stability of non-bone cement (biological) fixed prostheses is better than that of bone cement fixed prostheses. However, non-bone cement (biological) fixed prostheses currently generally fail to achieve ideal bony integration with the host bone, and only focus on the bony integration of the part inserted into the bone, without considering the bony integration of segmental diaphyseal prostheses.

[0006] Although porous titanium alloy prostheses have better toughness and mechanical properties than ceramics and biodegradable materials, making them better suited for repairing bone defects in load-bearing areas. However, the stress shielding effect caused by the mismatch between its elastic modulus (110GPa) and human bone (2-15GPa) will lead to bone absorption inside the pores, affecting long-term biological stability. In addition, the artifacts caused by metal shielding of radiation also make it difficult to evaluate the repair effect of implants. Therefore, the development of a bone repair prosthesis material with high mechanical compatibility, good bone ingrowth effect and easy evaluation has always been the focus and difficulty in the field of orthopedics and materials science.

[0007] The current prostheses still have the following problems:

[0008] 1) Current prosthesis designs all adopt a solid design, ignoring the effect of bone marrow on bone defect repair and immune regulation;

[0009] 2) The current design of fixation has always been based on bone cement fixation. The single bone cement fixation method is obviously no longer suitable for current treatment needs, and the high long-term loosening rate of bone cement fixed prostheses has been difficult to solve. Therefore, the single bone cement fixation method has become a major bottleneck restricting the development of segmental diaphyseal prostheses. Non-bone cement fixed prostheses use the principle of biological fixation to achieve bony integration between the prosthesis and the host bone, which can fundamentally solve the problem of long-term loosening of bone cement fixed prostheses. At present, there are many and in-depth studies on its fixation mechanism and effect. It is generally believed that the long-term stability of non-bone cement (biological) fixed prostheses is better than that of bone cement fixed prostheses. However, non-bone cement (biological) fixed prostheses currently generally fail to achieve ideal bony integration with the host bone, and only focus on the bony integration of the part inserted into the bone, without considering the bony integration of segmental diaphyseal prostheses.

[0010] 3) Currently, prostheses are mainly made of titanium alloys. However, the stress shielding effect caused by the mismatch between the elastic modulus of titanium alloys (110G Pa) and human bones (2-15GPa) will lead to bone absorption inside the pores, affecting long-term biological stability. In addition, the artifacts caused by metal shielding of radiation also make it difficult to evaluate the repair effect of implants. Polyetheretherketone polymer materials have excellent mechanical properties and biocompatibility, and their elastic modulus (3.8Gpa) is similar to that of bone tissue. At the same time, they have the advantages of light weight, wear resistance, fatigue resistance and good radiation penetration, thus becoming an important artificial bone transplant material to replace metals. Summary of the invention

[0011] The utility model aims to provide a porous PEEK prosthesis with a modular mortise and tenon structure with a medullary hole for repairing humeral shaft bone defects, which can achieve mechanical and biological compatibility between the prosthesis and the bone, accelerate and strengthen bone defect repair, and achieve long-term bone stability.

[0012] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a porous PEEK prosthesis reconstruction part composed of two mortise and tenon structures that are inserted into each other and locked by a tenon, and a prosthesis stem with a medullary hole is respectively provided at both ends of the porous PEEK prosthesis reconstruction part, and the medullary hole of the prosthesis stem is connected to the porous PEEK prosthesis reconstruction part.

[0013] The voids of the reconstructed part of the porous PEEK prosthesis adopt a diamond-shaped structure with a porosity of 50%. The diameter of the PEEK prosthesis wire is 400um, the average pore diameter is 400um, and the pore connectivity is 100%.

[0014] The shape and diameter of the prosthesis stem and the reconstruction part are the same as those of the bone defect of the patient's humeral shaft.

[0015] The diameter of the prosthesis stem is smaller than the diameter of the humeral shaft bone.

[0016] The length of the prosthesis stem is half of the length of the reconstruction part.

[0017] The backbone prosthesis of the utility model is a biologically fixed porous PEEK prosthesis with large pore size, high porosity and high connectivity, which solves the shortcomings of current materials such as titanium alloys. The precise connection of the mortise and tenon structure is more firm and stable than screw fixation, and there is no risk of failure of prosthesis implantation due to screw withdrawal or broken nails. At the same time, it is simpler, faster and shortens the operation time than screw installation. The porous prosthesis with medullary holes of the utility model can promote the growth of the distal and proximal prosthesis handles and the reconstructed bone segments, restore the bone length at an early stage, play a temporary supporting and stabilizing role, enable patients to move early, reduce the occurrence of complications, and improve the living standards of patients. At the same time, it realizes the simultaneous growth of bones inside and outside the bone, promotes the growth of bones and blood vessels into the internal pores, and the new bone growing into the pores can form a mechanical lock with the prosthetic material, shortening the bone defect repair time and achieving long-term stability.

[0018] The utility model designs a medullary hole on the prosthesis, so that the bone prosthesis and the medullary cavity between the backbone can be connected, and the positive promoting effect of the bone marrow on bone repair can be brought into play. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0020] Figure 2 It is a schematic diagram of the void diamond-shaped structure of the reconstruction part of the porous PEEK prosthesis of the utility model. DETAILED DESCRIPTION

[0021] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0022] See also Figure 1 The utility model comprises a porous PEEK prosthesis reconstruction part 1 composed of two mortise and tenon structures which are inserted into each other and locked by a tenon 4. A prosthesis stem 3 with a medullary hole 2 is respectively arranged at both ends of the porous PEEK prosthesis reconstruction part 1. The medullary hole 2 of the prosthesis stem 3 is connected with the porous PEEK prosthesis reconstruction part 1. The shape and diameter of the prosthesis stem 3 and the reconstruction part 1 are the same as those of the defective part of the patient's humeral shaft. In order to facilitate the insertion of the prosthesis stem 3 into the patient's humeral shaft, the diameters of the two ends of the prosthesis stem 3 are slightly smaller than the actual diameter of the patient's humeral shaft, and the length of the prosthesis stem 3 is half of the length of the reconstruction part 1.

[0023] See also Figure 2 According to the criteria of optimal mechanical strength and minimal internal stress concentration, the voids in the porous PEEK prosthesis reconstruction part 1 of the utility model adopt a diamond-shaped structure with a porosity of 50%, a PEEK prosthesis wire diameter of 400um, an average pore diameter of 400um, and a pore connectivity of 100%.

[0024] The utility model adopts a diamond-shaped porous prosthesis to promote bone and blood vessel growth. At the same time, a medullary hole is designed on the prosthesis, so that the bone prosthesis can penetrate the bone marrow cavity between the vertebrae, exerting the immune regulation and osteogenesis of the bone marrow. Combining these two designs to imitate the physiological structure of the humeral shaft is conducive to accelerating the healing of bone defects and long-term stability.

[0025] The utility model is a prosthesis with multiple pores all over the body combined with biological fixation, which promotes the ingrowth of the distal and proximal prosthesis stems and the reconstructed bone segments, can restore the bone length at an early stage, and play a temporary supporting and stabilizing role, so that patients can move early, reduce the occurrence of complications, and improve the patients' living standards. At the same time, bone ingrowth inside and outside the bone is achieved, and the growth of bone and blood vessels into the internal pores is promoted. The new bone growing into the pores can form a mechanical lock with the prosthetic material, shortening the bone defect repair time and achieving long-term stability.

[0026] Polyetheretherketone polymer material has excellent mechanical properties and biocompatibility, and its elastic modulus (3.8Gpa) is similar to that of bone tissue. It also has the advantages of light weight, wear resistance, fatigue resistance and good radiation penetration, making it an important artificial bone transplant material to replace metal.

[0027] Combining the mortise and tenon structure with porous ether ether ketone polymer material, precise connection makes the fixation more firm and stable, while there is a certain degree of flexible deformation, which is more in line with the physiological structure of human bones and promotes bone repair.

Claims

1. A porous PEEK prosthesis with a modular mortise and tenon structure with a medullary hole for repairing humeral shaft bone defects, characterized in that: The invention comprises a porous PEEK prosthesis reconstruction part (1) composed of two mortise and tenon structures which are inserted into each other and locked by a tenon (4), and a prosthesis stem (3) with a medullary hole (2) is respectively arranged at both ends of the porous PEEK prosthesis reconstruction part (1), and the medullary hole (2) of the prosthesis stem (3) is connected to the porous PEEK prosthesis reconstruction part (1).

2. The porous PEEK prosthesis with a modular mortise and tenon structure with a medullary hole for repairing humeral shaft bone defects according to claim 1, characterized in that: The voids of the porous PEEK prosthesis reconstruction part (1) adopt a diamond-shaped structure with a porosity of 50%. The PEEK prosthesis wire diameter is 400um, the average pore diameter is 400um, and the pore connectivity is 100%.

3. The porous PEEK prosthesis with a modular mortise and tenon structure with a medullary hole for repairing humeral shaft bone defects according to claim 1, characterized in that: The shape and diameter of the prosthesis stem (3) and the reconstruction part (1) are the same as those of the defective part of the humeral shaft of the patient.

4. The porous PEEK prosthesis with a modular mortise and tenon structure with a medullary hole for repairing humeral shaft bone defects according to claim 1, characterized in that: The diameter of the prosthesis stem (3) is smaller than the diameter of the humeral shaft.

5. The porous PEEK prosthesis with a modular mortise and tenon structure with a medullary hole for repairing humeral shaft bone defects according to claim 1, characterized in that: The length of the prosthesis stem (3) is half the length of the reconstruction part (1).

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