Tantalum metal prosthesis for femoral head necrosis

Abstract

The invention relates to a tantalum metal prosthesis for femoral head necrosis, which comprises a prosthesis body, a tantalum metal layer is vapor deposited on the prosthesis body, and a positioning groove is formed in the prosthesis body; the prosthesis body is provided with an end head and an end tail which are opposite to each other; the size of the prosthesis body is gradually reduced in the direction from the end head to the end tail; wherein the end face of the end head is a cambered surface. On the premise that the minimally invasive advantage is guaranteed, biomechanical distribution is optimized through structural innovation, bone mass loss is reduced, operation accuracy is improved, and therefore the problems that in the prior art, the rebuilding rate is high, bone integration efficiency is low, and long-term stability is insufficient are solved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of artificial joints, and in particular to a tantalum metal prosthesis for treating femoral head necrosis. Background Art

[0002] As a common orthopedic disease, femoral head necrosis has developed a variety of artificial joint implant technologies in the field of hip-preserving surgery. Among them, the femoral head reconstruction rod is a typical representative. It is implanted through minimally invasive surgery to restore the morphological structure of the femoral head, improve joint function and delay the timing of total hip replacement.

[0003] Existing femoral head reconstruction rods are often made of biocompatible materials such as titanium alloys. They offer minimally invasive procedures (small incision, minimal bleeding), a short postoperative recovery period, and excellent bone integration. Their typical structure extends from the greater trochanter through the femoral neck to the necrotic area, maintaining the femoral head's shape through mechanical support. However, clinical validation and technical analysis have revealed that existing femoral head reconstruction rods still suffer from the following technical deficiencies: 1. Insufficient implant life and stability: Although existing reconstruction rods can delay femoral head collapse, long-term use can easily lead to material wear or interface loosening due to stress concentration, making secondary revision surgery inevitable. During revision, the tantalum metal prosthesis needs to be cut off, and the resulting debris is difficult to completely remove, significantly increasing the complexity of the surgery and the risk of infection.

[0004] 2. Biomechanical adaptability defects: Traditional reconstruction rods use a linear long rod structure of ≥70mm (such as products imported from a US company), which needs to penetrate the femoral head to the greater trochanter area to form a drilling channel, resulting in excessive bone loss. In addition, due to the intraoperative insertion angle and femoral neck anteversion deviation, it is difficult to accurately locate the apex of the necrotic area, resulting in unsatisfactory support effect, which can easily cause prosthesis displacement or postoperative collapse recurrence.

[0005] 3. Problem of postoperative bone regeneration inhibition: The penetrating bone defect formed by the long rod structure hinders the natural repair process of local bone tissue. Although porous tantalum metal can promote bone ingrowth, the stress shielding effect caused by excessive bone resection will still weaken the bone reconstruction effect and affect the long-term efficacy.

[0006] Based on the above technical problems, this field urgently needs to develop a new type of femoral head reconstruction rod, which needs to optimize biomechanical distribution, reduce bone loss and improve surgical precision through structural innovation while ensuring the advantages of minimally invasive surgery, so as to break through the problems of high revision rate, low bone integration efficiency and insufficient long-term stability in existing technologies. Summary of the Invention

[0007] The purpose of the present disclosure is to provide a tantalum metal prosthesis for femoral head necrosis, so as to optimize biomechanical distribution, reduce bone loss and enhance surgical precision by improving its structure, thereby overcoming the problems of high revision rate, low bone integration efficiency and insufficient long-term stability in the prior art.

[0008] In order to achieve the above-mentioned objectives, the present disclosure provides a tantalum metal prosthesis for femoral head necrosis, comprising a prosthesis body, a tantalum metal layer vapor-deposited on the prosthesis body, and a positioning groove provided on the prosthesis body; the prosthesis body has opposite ends and tails; the size of the prosthesis body gradually decreases along the direction from the end to the tail; wherein the end face of the end is formed as an arc surface.

[0009] In one possible design, the prosthesis body is made of carbon foam.

[0010] In a possible design, the porosity of the prosthesis body is 60% to 90%, and the porosity of the tantalum metal layer is 60% to 90%.

[0011] In one possible design, the porosity is distributed along a gradient, wherein the porosity of the head region is greater than the porosity of the tail region.

[0012] In a possible design, the height of the positioning groove is h, and the overall height of the prosthesis body is H, wherein H / 3≤h≤H / 2.

[0013] In a possible design, the positioning groove is square.

[0014] In one possible design, the taper α of the prosthesis body is 10°~12.5°.

[0015] In a possible design, the edges of the end head and the end tail of the prosthesis body are both set as arc angles.

[0016] In a possible design, the groove edge of the positioning groove is configured as a smooth curved surface.

[0017] Through this technical solution, the curved tip design increases the contact area by 40%-60% (compared to traditional cylindrical tips), reducing the pressure in the necrotic zone to below 15 MPa (below the trabecular bone yield threshold), effectively preventing secondary fractures during surgery. The tapered structure achieves anatomical adaptation to the femoral neck anatomy, reducing the cross-sectional area of ​​the bone channel by 35%, preserving more healthy bone mass. The gradient porosity of the tantalum metal layer enables bone ingrowth rates of up to 200 μm / month in the tip region (120 μm / month in the main region), creating a progressively strengthening interface from the outside in. The positioning grooves and navigation system work together to control angular deviation to within ±2° (compared to ±8° with traditional implant techniques), significantly reducing the risk of prosthesis dislocation. Furthermore, the tantalum metal prosthesis achieved through this application has a length of 25 mm to 50 mm (compared to the traditional 70 mm), avoiding penetration through the greater trochanter and effectively reducing the amount of tantalum metal debris generated during osteotomy revision. Therefore, under the premise of ensuring the advantages of minimally invasive surgery, it is possible to optimize biomechanical distribution, reduce bone loss and improve surgical precision through structural innovation, thereby solving the problems of high revision rate, low bone integration efficiency and insufficient long-term stability in existing technologies.

[0018] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 is a schematic diagram of the three-dimensional structure of a tantalum metal prosthesis in one embodiment; Figure 2 is a schematic diagram of the main structure of a tantalum metal prosthesis in one embodiment; Figure 3 This is a schematic diagram of the structure of a tantalum metal prosthesis implanted in the femoral head; Figure 4 This is the first image of experimental group 1 implanted immediately after surgery; Figure 5 This is the second image of experimental group 1 implanted immediately after surgery; Figure 6 This is the image of control group 1 implanted immediately after surgery; Figure 7 This is the first image of experimental group 2 implanted four weeks after surgery; Figure 8 This is the second image of experimental group 2 implanted four weeks after surgery; Figure 9 This is the image of control group 2 implanted four weeks after surgery; Figure 10 This is the first image of experimental group 3 implanted immediately after surgery; Figure 11 This is the second image of experimental group 3 implanted immediately after surgery; Figure 12 This is the image of control group 3 implanted immediately after surgery; Figure 13 This is the first image of the experimental group 4 implanted twelve weeks after surgery; Figure 14 This is the second image of the experimental group 4 implanted twelve weeks after surgery; Figure 15 This is the image of the control group 4 implanted twelve weeks after surgery; Figure 16 This is the first image of experimental group 5 implanted immediately after surgery; Figure 17 This is the second image of experimental group 5 implanted immediately after surgery; Figure 18 This is the image of control group 5 implanted immediately after surgery; Figure 19 This is the first image of the experimental group 6 implanted twenty-six weeks after surgery; Figure 20 This is the second image of the experimental group 6 implanted twenty-six weeks after surgery; Figure 21 This is an image of the control group 6 implanted 26 weeks after surgery.

[0020] Description of Reference Numerals 1-femoral head, 2-prosthesis body, 21-end, 22-tail, 3-positioning groove. DETAILED DESCRIPTION

[0021] The specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0022] According to the first aspect of the present disclosure, Figures 1 to 21 As shown, the tantalum metal prosthesis for femoral head necrosis 1 includes a prosthesis body 2, a tantalum metal layer is vapor-deposited on the prosthesis body 2, and a positioning groove 3 is provided on the prosthesis body 2; the prosthesis body 2 has a relative end 21 and a tail 22, and the size of the prosthesis body 2 gradually becomes smaller along the direction from the end 21 to the tail 22; wherein, the end face of the end 21 is formed into an arc surface.

[0023] Since the end 21 of the prosthesis adopts an expanded arc surface structure (the radius of curvature matches the necrotic area of ​​the femoral head 1), the stress is dispersed through the surface contact between the end face and the necrotic bone after implantation, avoiding the problem of excessive local pressure caused by the point support of traditional rod-shaped prostheses; the tantalum metal layer deposited by vapor phase on the surface of the prosthesis body 2 forms a porous bone conduction interface, and its porosity is beneficial to guiding the directional growth of new bone tissue along the axial direction of the prosthesis, achieving spatiotemporal adaptation of mechanical strength and bone ingrowth efficiency; the positioning groove 3 serves as a spatial orientation marker, cooperating with the optical / electromagnetic signal receiver of the intraoperative navigation system to provide real-time feedback on the axial deflection angle of the prosthesis to ensure that the implantation trajectory coincides with the necrotic area target planned before surgery.

[0024] The procedure for using this tantalum prosthesis is as follows: The extent of femoral head necrosis 1 is determined based on CT three-dimensional reconstruction, and the curvature of the curved surface of the end 21 and the taper parameters of the prosthesis are calculated. The prosthesis implantation path is set in the navigation system, and the matching relationship between the positioning slot 3 and the guide instrument is planned. A bone channel is established through a minimally invasive incision in the greater trochanter, and a medullary reamer is used to form a stepped channel that matches the prosthesis. The guide clip is engaged with the prosthesis positioning slot 3, and the implantation angle is adjusted using monitoring by the navigation system. The prosthesis is inserted along the preset path until the curved surface of the end 21 completely aligns with the subchondral bone plate in the necrotic area. After removing the guide, C-arm X-rays are used to verify the prosthesis' position and support effectiveness. New bone tissue within the pores of the tantalum metal layer completes primary ingrowth within 6-8 weeks, forming a mechanical interlock. The radial compressive stress generated by the tapered structure continuously stimulates bone remodeling, achieving complete biological fixation of the prosthesis-bone interface after 12 months.

[0025] Through this technical solution, the curved surface design of tip 21 increases the contact area by 40%-60% (compared to a conventional cylindrical tip 21), reducing the pressure in the necrotic zone to below 15 MPa (below the trabecular bone yield threshold), effectively preventing secondary fractures during surgery. The tapered structure achieves anatomical adaptation to the femoral neck anatomy, reducing the cross-sectional area of ​​the bone channel by 35%, preserving more healthy bone mass. The gradient porosity of the tantalum metal layer enables bone ingrowth rates of up to 200 μm / month in the tip 21 region (compared to 120 μm / month in the main region). The positioning groove 3, in conjunction with the navigation system, controls angular deviation within ±2° (compared to ±8° with conventional implants), significantly reducing the risk of prosthesis dislocation. Furthermore, the resulting tantalum metal prosthesis, with a length of 25 to 50 mm (compared to a conventional 70 mm), avoids penetrating the greater trochanter and effectively reduces the amount of tantalum metal debris generated during revision osteotomy. Therefore, under the premise of ensuring the advantages of minimally invasive surgery, it is possible to optimize biomechanical distribution, reduce bone loss and improve surgical precision through structural innovation, thereby solving the problems of high revision rate, low bone integration efficiency and insufficient long-term stability in existing technologies.

[0026] In one embodiment provided by the present disclosure, the prosthesis body 2 is made of foamed carbon.

[0027] Carbon foam material has good biocompatibility, will not cause immune response or inflammatory response in the human body, and can coexist harmoniously with human tissue. As a result, the prepared carbon foam prosthesis can be accepted by the human body after implantation into the human body, and will not produce rejection reaction, thereby improving the service life of the prosthesis and the comfort of the patient. The porous structure of carbon foam is conducive to the growth and integration of bone tissue, so that the prosthesis is closely combined with the bone tissue to form a stable bone integration interface. This bone integration not only enhances the stability of the prosthesis, but also helps to restore the mechanical properties of the femoral head 1 and promote the patient's recovery. In addition, carbon foam material has the characteristics of low density and high strength, which can reduce the weight of the prosthesis while ensuring the strength of the prosthesis. This enables the implanted prosthesis to effectively disperse stress when it is subjected to the mechanical load of the femoral head 1, reducing the risk of collapse of the femoral head 1 and alleviating the burden on the patient.

[0028] The porous structure of the foamed carbon provides an excellent space and environment for the growth of bone tissue, and is also conducive to the attachment, proliferation, and differentiation of bone cells. Bone tissue can grow into the prosthesis through these pores, forming a strong connection with the prosthesis, improving the stability and long-term effectiveness of the prosthesis. At the same time, it can also effectively reduce the stress shielding effect and make the stress distribution of the femoral head 1 more uniform. This helps maintain the normal physiological stress environment of the femoral head 1, promotes the natural repair and reconstruction of bone tissue, and improves the patient's long-term therapeutic effect.

[0029] In the present disclosure, the porosity of the prosthesis body 2 is 60% to 90%, and the porosity of the tantalum metal layer is 60% to 90%. The high-porosity prosthesis body 2 and the tantalum metal layer provide ample space and a good environment for the growth and proliferation of bone cells. Bone cells can grow into the prosthesis through these pores and form a strong connection with the prosthesis, thereby achieving the integration of bone tissue and prosthesis. The porous structure significantly increases the contact area between the prosthesis and bone tissue, which helps to improve the initial stability and long-term stability of the prosthesis. This stable bone integration interface can effectively reduce the risk of prosthesis loosening and extend the service life of the prosthesis.

[0030] By adjusting the porosity of the porous structure, the elastic modulus of the prosthesis can be changed to make it closer to the elastic modulus of bone tissue, which helps to avoid the stress shielding effect, make the stress distribution of the femoral head 1 more uniform, and promote the natural repair and reconstruction of bone tissue.

[0031] Although the tantalum metal prosthesis disclosed herein has a high porosity, the porous tantalum metal layer structure still provides high mechanical strength. When the tantalum layer is 50 μm thick, the maximum compressive and shear strengths are 35-40 MPa, meeting the mechanical requirements of the femoral head prosthesis. Furthermore, due to the inherent biological inertness of tantalum, it is not susceptible to bacterial colonization or adhesion.

[0032] Furthermore, the porosity is distributed along a gradient, wherein the porosity of the end 21 region is greater than the porosity of the end tail 22 region. Furthermore, the porosity of the prosthesis body 2 is distributed along a gradient, wherein the porosity of the end 21 region is greater than the porosity of the end tail 22 region. Specifically, the higher porosity of the end 21 region provides a larger space, which is conducive to the growth and proliferation of bone cells. This helps to closely integrate the bone tissue with the prosthesis, forming a stable bone integration interface. The high-porosity end 21 region increases the contact area between the prosthesis and the bone tissue, which helps to improve the initial stability and long-term stability of the prosthesis.

[0033] Through the gradient porosity design, the elastic modulus of the prosthesis can be made different in different areas, better matching the elastic modulus of the bone tissue, helping to avoid the stress shielding effect and making the stress distribution of the femoral head 1 more uniform. The lower porosity in the end-tail 22 area can maintain the mechanical strength of the prosthesis and ensure its stability when subjected to mechanical loads. In this way, the gradient porosity design provides good conditions for the growth and repair of bone tissue, helping to accelerate the recovery of bone tissue after surgery. Bone cells can quickly grow into the prosthesis and form new bone tissue, thereby speeding up the patient's recovery.

[0034] In the present disclosure, the height of the positioning groove 3 is h, and the overall height of the prosthesis body 2 is H, where H / 3 ≤ h ≤ H / 2. This arrangement helps the surgeon accurately determine the implant depth and direction of the prosthesis by observing the position of the positioning groove 3 during surgery, thereby ensuring that the prosthesis is accurately implanted in the intended location and reducing surgical errors. Furthermore, during postoperative follow-up, the surgeon can also accurately determine the position and stability of the prosthesis by observing the position of the positioning groove 3, helping to promptly detect prosthesis displacement or other complications and take appropriate treatment measures.

[0035] In the present disclosure, the groove shape of the positioning groove 3 is square. The square groove shape has obvious edges, so that during the operation, the doctor can observe the position and direction of the positioning groove 3 more clearly, which is conducive to improving the accuracy and efficiency of the operation and reducing surgical errors. In addition, the edges and right angles of the square groove shape can form a closer contact with the bone tissue, which can provide a better mechanical locking effect, making the prosthesis more stable after implantation and reducing the risk of prosthesis displacement. In addition, the edges and right angles of the square groove shape provide different surface roughness, which is conducive to the attachment and proliferation of bone cells, so that the bone tissue is better combined with the prosthesis, and then a stable bone integration interface is formed.

[0036] The square slot shape is highly visible on imaging studies (such as X-rays and CT scans), making it easier for doctors to observe the position and stability of the prosthesis after surgery. The edges and right angles of the square slot are clearly visible in imaging images, helping doctors accurately assess the performance and effectiveness of the prosthesis. The right angles and edges of the square slot serve as reference points to help doctors evaluate the mechanical properties and osseointegration of the prosthesis.

[0037] In the present disclosure, the taper α of the prosthesis body 2 is 10°~12.5°, that is, the prosthesis body 2 has a tapered structure. Such a design helps to reduce the resistance during implantation, so that the prosthesis can more smoothly enter the necrotic area of ​​the femoral head 1 during the implantation process, and reduce the damage to the surrounding bone tissue during the implantation process, reducing surgical trauma and surgical difficulty. At the same time, it also enables the prosthesis to better combine with the bone tissue after implantation to form a mechanical locking effect. The tapered structure based on the prosthesis body also helps to increase the contact area between the prosthesis and the bone tissue and improve the stability of the prosthesis. In addition, the taper design can also increase the contact area between the prosthesis and the bone tissue, which helps the growth and integration of the bone tissue, thereby providing more surface roughness, which is conducive to the attachment and proliferation of bone cells.

[0038] Furthermore, the tapered design provides a distinct feature in imaging studies (such as X-rays and CT scans), making it easier for doctors to observe the position and stability of the prosthesis after surgery. The tapered structure is clearly visible in imaging images, facilitating accurate assessments. During postoperative functional evaluations, doctors can more easily assess the performance and effectiveness of the prosthesis, helping them evaluate its mechanical properties and osseointegration.

[0039] Furthermore, the edges of the end 21 and the end tail 22 of the prosthesis body 2 are all set to arc angles. The arc angle design enables the prosthesis to enter the necrotic area of ​​the femoral head 1 more smoothly during the implantation process, reduces the resistance during implantation, and reduces the difficulty of the operation. At the same time, it is also possible to reduce the damage to the surrounding bone tissue and soft tissue during the implantation process, reduce surgical trauma, and promote postoperative recovery. During the implantation process, it is also possible to avoid cutting and tearing of muscle tissue by the edges, thereby reducing the risk of postoperative pain and complications.

[0040] In the present disclosure, the groove edge of the positioning groove 3 is set to a smooth curved surface, which can increase the contact area between the prosthesis and the bone tissue, guide the bone tissue to grow along the surface of the prosthesis, promote the uniform distribution of the bone tissue, help the growth and integration of the bone tissue, and form a stable bone integration interface.

[0041] The tantalum metal prosthesis provided in this disclosure has a multi-access adaptability feature, allowing flexible selection of implantation paths based on the stage of femoral head necrosis, degree of collapse, and surgical procedure preference. In this disclosure, the tantalum metal prosthesis for femoral head necrosis has at least three usage methods. The following examples illustrate its usage with reference to typical clinical application scenarios: 1. ARCO stage I-II, no collapse or mild collapse; a greater trochanteric approach is selected, entering from the greater trochanter to reach the interior of the femoral head. The patient lies supine with the affected hip elevated. A tantalum rod is then placed to support the collapsed area, lifting the collapsed subchondral bone plate, restoring joint surface flatness, and delaying the progression of secondary arthritis.

[0042] 2. A direct anterior approach (DAA) was selected, entering through the gap between the tensor fasciae latae and the sartorius muscles, avoiding muscle severing and preserving the greater trochanteric structure. In line with the minimally invasive concept, a fenestration (approximately 8-10 mm in diameter) was created at the junction of the femoral head and neck, directly accessing the subchondral bone necrosis without damaging the normal bone of the greater trochanter. The tantalum rod was implanted along the fenestration channel, with its axis perpendicular to the weight-bearing area of ​​the femoral head, directly supporting the collapsed area.

[0043] 3. A surgical dislocation approach (Ganz approach) is chosen. Through a posterior Kocher-Langenbeck incision, a greater trochanter osteotomy and gluteus medius rotation are performed, preserving the branches of the medial circumflex femoral artery (MFCA) to avoid iatrogenic femoral head ischemia. This allows for 360-degree exposure of the acetabulum and femoral head. Necrotic foci are removed under direct vision, and the degree of articular surface collapse is accurately assessed. A T-shaped incision is made in the joint capsule, and the femoral head is dislocated to the outside of the acetabulum to fully expose the necrotic area. Scrutinized bone is scraped to the bleeding bone surface, preserving the integrity of the subchondral bone plate. Depending on the extent of necrosis, two to three tantalum rods are implanted, arranged in a fan-shaped or parallel pattern, covering the primary weight-bearing area, with the ends embedded in healthy cancellous bone.

[0044] It should be noted that the present disclosure is merely an example description, and those skilled in the art may select different approaches based on the patient's specific condition, and the present disclosure does not limit this.

[0045] In order to further verify the clinical effect of the tantalum metal prosthesis, animal experiments were conducted on the tantalum metal prosthesis (experimental group) and the prior art prosthesis (control group).

[0046] First, a distal femoral defect model was created in Labrador dogs. The experimental article (experimental group) and the control article (control group) were implanted into the animal bone defect model. By comparing the test index results of the experimental group, control group, and sham operation group, the safety and effectiveness of the experimental article in the animal implantation experiment were evaluated.

[0047] The main instruments include: TCS-150A electronic scale, veterinary respiratory anesthesia machine, veterinary respiratory anesthesia machine, CT tomography electronic scanner, X-ray micro CT, Olympus BX51 microscope, digital X-ray camera DR.

[0048] The main reagents are: propofol, isoflurane, normal saline, normal saline, normal saline, lidocaine.

[0049] Compared to small animals, large animals have bone metabolism mechanisms similar to humans. Their bones are also thicker and harder, making bone defect modeling easier. Furthermore, canine bone tissue density, quality, and organic / inorganic components are very similar to those of humans. Furthermore, dogs are easy to raise, approach, and obtain widely. Therefore, dogs were chosen as the experimental animals for this study.

[0050] The experimental process is as follows: 1. Quarantine process Quarantine and Isolation: The supplier will provide all animal vaccination and deworming records. Animals will be quarantined and acclimated at our facility for at least seven days prior to surgery. During this period, animals will be evaluated according to the criteria listed in Table 1. Based on the results of this evaluation, animals deemed unsuitable for this study will be removed prior to randomization.

[0051] 2. Experimental Grouping In this animal experiment, 23 dogs were divided according to body weight into an experimental group, a control group, and a sham-surgery group (no more than ±20% of mean body weight). The experimental and control groups each consisted of 9 animals, and the sham-surgery group consisted of 3 animals. One spare animal was kept in each group. Observation time points were set at 4, 12, and 26 weeks after surgery, with 3 animals in each group observed at each time point. Dissection and histopathology were performed only at the final observation point (26 weeks) for the 3 animals in the sham-surgery group. Examinations other than the two aforementioned parameters (dissection and histopathology) were performed at all other time points.

[0052] 3. Sample size The experimental and control groups consisted of nine Labrador dogs each. A defect was created on the right femoral condyle of each dog, and one filler material was implanted. Nine fillers were required for each group.

[0053] The detection indicators are as follows: 1. Imaging examination (abbreviated as DR) The imaging results of the experimental group and the control group showed that 4 weeks after surgery, compared with immediately after surgery, the gap-like low-density shadow that was originally visible around the implanted sample was no longer visible, that is, the new bone filled the gap, and callus was visible wrapping the sample at the medial condyle of the femur. The shape, size, and density of the implanted sample did not show obvious changes, and the position did not change; 4 weeks after surgery, the gap around the implanted sample was filled with new bone, and callus was visible.

[0054] Compared with the data immediately after surgery, the gap-like low-density shadow that was originally visible around the implanted sample disappeared 12 weeks after surgery - that is, the new bone filled the gap. The shape, size, and density of the implanted sample did not show obvious changes, and the position did not change. Compared with the data twelve weeks ago, the gap around the sample was filled with new bone.

[0055] Compared with the situation immediately after surgery, the low-density gaps around the implanted samples disappeared 26 weeks after surgery, indicating that the gaps were filled with new bone. The shape, size, and density of the implanted samples did not change significantly, and their positions did not change.

[0056] From the images of the sham operation group, we can see that the animal defect model did not reach the critical value of the animal femoral defect, did not affect the normal growth of the bone, and verified that the slight differences in surgical operation did not affect the growth of the animal. Figures 4 to 21 .

[0057] exist Figure 4 and Figure 5 Imaging results of experimental group 1 immediately after surgery: The implanted samples were visible at the medial condyle of the right femur in all experimental animals in experimental group 1. After the implantation of the samples, gap-like low-density shadows were visible around them, indicating incomplete fitting; there were no obvious abnormalities in the shape, size, and density of the implanted samples; there were no obvious discontinuities or abnormal density shadows in the bones around the surgical site of the experimental animals; there was no obvious swelling or abnormal density shadows in the soft tissues around the surgical site; and no other obvious abnormalities were found.

[0058] exist Figure 6 Imaging results of control group 1 immediately after surgery: All experimental animals in the control group had implanted samples at the medial condyle of the right femur, and there were gap-like low-density shadows around the samples after implantation, indicating incomplete fitting; in the soft tissue around the implanted samples of experimental animal control group 1, there were many point-like high-density shadows, indicating broken sample particles; there were no obvious abnormalities in the shape, size, and density of the remaining implanted samples; there were no obvious discontinuities or abnormal density shadows in the bones around the surgical site.

[0059] exist Figure 7 and Figure 8 In the imaging results of experimental group 2 four weeks after surgery: the implanted samples were visible at the medial femoral condyle of the right knee joint of all experimental animals in experimental group 2. Compared with the data immediately after surgery, the originally visible gap-like low-density shadow around the implanted samples was no longer visible, that is, the new bone filled the gap, and callus wrapped around the samples was visible at the medial femoral condyle. The shape, size, and density of the implanted samples did not show obvious changes, and the position did not change. Compared with the data four weeks ago, the gaps around the samples were filled with new bone, and callus was visible.

[0060] exist Figure 9 In the imaging results of the control group 2 four weeks after surgery: the implanted samples were visible at the right medial femoral condyle of all experimental animals in the experimental group. Compared with the immediate postoperative period, the low-density gap-like shadows that were originally visible around the implanted samples were no longer visible - that is, the new bone filled the gap; the sample fragments were still visible in the soft tissue around the surgical site of experimental animal 1103; the sample was wrapped in callus at the medial femoral condyle, and there was no obvious abnormal change in the shape, size, and density of the implanted sample, and the position did not change; compared with the data four weeks ago, the gap around the sample implant was filled with new bone, and callus was visible.

[0061] exist Figure 10 and Figure 11 Imaging results of experimental group 3 immediately after surgery: The implanted samples were visible at the medial condyle of the right femur in all experimental animals in experimental group 3. After the implantation of the samples, a gap-like low-density shadow was visible around them, indicating incomplete fitting; there were no obvious abnormalities in the shape, size, and density of the implanted samples; there were no obvious discontinuities or abnormal density shadows in the bones around the surgical site of the experimental animals; the soft tissue around the surgical site was slightly swollen and gas density shadows were visible inside it; there were no other obvious abnormalities.

[0062] exist Figure 12 In the figure, the imaging results of the control group 3 immediately after surgery were as follows: Immediately after surgery, all experimental animals in the control group 3 had implanted samples at the medial condyle of the right femur, and there were gap-like low-density shadows around the samples after implantation, indicating incomplete fitting; the arc shape of the upper edge of the implanted samples in the experimental animal control group disappeared, and there were no obvious abnormalities in the shape, size, and density of the remaining implanted samples; gas density shadows were seen in the soft tissue around the surgical site; no obvious discontinuity or abnormal density shadows were seen in the bones around the surgical site.

[0063] exist Figure 13 and Figure 14 In the imaging results of experimental group 4 twelve weeks after surgery: the implanted samples were visible at the medial condyle of the right femur in all experimental animals of experimental group 4. Compared with the data immediately after surgery, the gap-like low-density shadow that was originally visible around the implanted samples was no longer visible - that is, the new bone filled the gap. The shape, size, and density of the implanted samples did not show obvious changes, and the position did not change. Compared with the data twelve weeks ago, the gaps around the samples were filled with new bone.

[0064] exist Figure 15 In the imaging results of the control group 4 twelve weeks after surgery: the implanted samples were visible at the right medial femoral condyle of each experimental animal in the control group 4. Compared with the data immediately after surgery, the gap-like low-density shadows that were originally visible around the implanted samples were no longer visible - that is, the new bone filled the gap; the upper edge of the implanted samples of experimental animals 1104 and 1106 still disappeared; a small amount of new bone was visible covering the upper edge of the implanted sample in experimental animal 1105, and there was no obvious abnormal change in the shape, size, and density of the remaining implanted samples, and the position did not change; compared with the data twelve weeks ago, the gaps around the implanted samples were filled with new bone.

[0065] exist Figure 16 and Figure 17Imaging results of experimental group 5 immediately after surgery: All experimental animals in experimental group 5 had implanted samples at the medial condyle of the right femur, and gap-like low-density shadows were visible around the implanted samples, indicating incomplete fitting; multiple point-like high-density shadows were visible around the 2109 implants, and the shape, size, and density of the remaining implanted samples showed no obvious abnormalities; no obvious discontinuity or abnormal density shadows were found in the bones around the surgical site of the experimental animals; the soft tissue around the surgical site was slightly swollen and gas density shadows were visible inside it; no other obvious abnormalities were found.

[0066] exist Figure 18 Imaging results of control group 5 immediately after surgery: All experimental animals in control group 5 had implanted samples at the medial condyle of the right femur, and there were gap-like low-density shadows around the samples after implantation, indicating incomplete fitting; there were no obvious abnormalities in the shape, size, and density of the remaining implanted samples; low-density gas shadows were visible in the soft tissue of the surgical site, and no obvious discontinuity or abnormal density shadows were seen in the bones around the surgical site.

[0067] exist Figure 19 and Figure 20 The imaging results of experimental group 6 26 weeks after surgery were as follows: the implanted samples were visible at the medial condyle of the right femur in all experimental animals of experimental group 6. Compared with the situation immediately after surgery, there was no obvious gap around the implanted samples - that is, the gap was filled with new bone. Multiple point-like high-density shadows were visible around the 2109 implants. The shape, size, density and position of the other implanted samples did not change significantly; there was no obvious abnormality in the soft tissue.

[0068] exist Figure 21 In the imaging results of the control group 26 weeks after surgery, the following were obtained: the implanted samples were visible at the medial condyle of the right femur in all experimental animals in the experimental group. Compared with the situation immediately after surgery, no obvious gap was found around the implanted samples - that is, the gap was filled with new bone. There were no obvious abnormal changes in the shape, size, and density of the implanted samples, and the position did not change. There were no obvious abnormalities in the surrounding soft tissues.

[0069] Combined with the drawings in the specification Figures 4 to 21 , it can be explained that: after implantation, the tantalum metal prosthesis disperses stress through the surface contact between the end face and the necrotic bone, avoiding the problem of excessive local pressure caused by the point support of traditional rod-shaped prostheses; the tantalum metal layer vapor-deposited on the surface of the prosthesis body forms a porous bone conduction interface, and its porosity is beneficial to guiding the directional growth of new bone tissue along the axial direction of the prosthesis, achieving spatiotemporal adaptation of mechanical strength and bone ingrowth efficiency; the positioning groove serves as a spatial orientation marker, cooperating with the optical / electromagnetic signal receiver of the intraoperative navigation system to provide real-time feedback on the axial deflection angle of the prosthesis, ensuring that the implant trajectory coincides with the necrotic area target planned before surgery. Therefore, under the premise of ensuring the advantages of minimally invasive surgery, structural innovation can be used to optimize biomechanical distribution, reduce bone loss, and improve surgical precision, thereby solving the problems of high revision rate, low bone integration efficiency, and insufficient long-term stability in existing technologies.

[0070] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

Claims

1. A tantalum metal prosthesis for femoral head necrosis, characterized in that: The invention comprises a prosthesis body, on which a tantalum metal layer is vapor-deposited, and on which a positioning groove is provided; the prosthesis body has an end head and an end tail opposite to each other; the size of the prosthesis body gradually decreases along the direction from the end head to the end tail; wherein the end face of the end head is formed into an arc surface.

2. The tantalum metal prosthesis for femoral head necrosis according to claim 1, characterized in that: The prosthesis body is made of foam carbon.

3. The tantalum metal prosthesis for femoral head necrosis according to claim 1, characterized in that: The porosity of the prosthesis body is 60% to 90%, and the porosity of the tantalum metal layer is 60% to 90%.

4. The tantalum metal prosthesis for femoral head necrosis according to claim 3, characterized in that: The porosity is distributed along a gradient, wherein the porosity of the head region is greater than that of the tail region.

5. The tantalum metal prosthesis for femoral head necrosis according to claim 1, characterized in that: The height of the positioning groove is h, and the overall height of the prosthesis body is H, wherein H / 3≤h≤H / 2.

6. The tantalum metal prosthesis for femoral head necrosis according to claim 1, characterized in that: The positioning groove is in a square shape.

7. The tantalum metal prosthesis for femoral head necrosis according to claim 1, characterized in that: The taper α of the prosthesis body is 10°~12.5°.

8. The tantalum metal prosthesis for femoral head necrosis according to claim 1, characterized in that: The edges of the end head and the end tail of the prosthesis body are both set as arc angles.

9. The tantalum metal prosthesis for femoral head necrosis according to claim 1, characterized in that: The groove edge of the positioning groove is set to a smooth curved surface.

Images