3D-printed personalized subtotal artificial femoral replacement prosthesis

Abstract

This application relates to the field of medical devices, and more particularly to a 3D-printed personalized subtotal femoral replacement prosthesis, comprising a 3D-printed femoral segment. One end of the 3D-printed femoral segment has a short medullary nail integrally formed therein, which is inserted into the remaining femoral medullary cavity after osteotomy. The end of the 3D-printed femoral segment away from the short medullary nail is connected to the proximal femur, which is used to connect to the femoral head prosthesis. A reinforcing screw is inserted within the 3D-printed femoral segment, coaxially arranged with the 3D-printed femoral segment, and is used to sequentially penetrate from the distal end of the remaining femur into the short medullary nail and the 3D-printed femoral segment. This application has the effect of improving the stability of the femoral replacement prosthesis.

Description

Technical Field

[0001] This application relates to the field of medical devices, and in particular to a 3D-printed, personalized, subtotal artificial femoral replacement prosthesis. Background Technology

[0002] The femur is the most important bone in the human body, and the femoral head is even more crucial, as it supports human upright walking, movement, and labor. For femoral defects caused by tumors, comminuted fractures, or other conditions, femoral replacement surgery is typically performed.

[0003] Reference Figure 1 Taking bone defect disease after proximal femoral resection as an example, the femoral replacement prosthesis includes the proximal femur 100, the femoral extension 200, and the medullary canal extension stem 300. The top end of the femoral extension 200 is connected to the proximal femur 100, and the bottom end of the femoral extension 200 is connected to the medullary canal extension stem 300.

[0004] Reference Figure 2 The proximal femur 100 is used to connect with the femoral head prosthesis, and the medullary canal extension stem 300 is inserted into the medullary canal of the remaining distal femur 400 for fixation.

[0005] However, when there is a small amount of distal femoral 400mm remaining after femoral osteotomy, the medullary canal extension stem 300 that matches the remaining distal femoral 400mm is relatively short. A shorter medullary canal extension stem 300 provides poor fixation and is prone to causing loosening of the femoral replacement prosthesis.

[0006] Reference Figure 3 In clinical practice, in order to improve the stability of the femoral replacement prosthesis, a lateral plate 500 is usually used to fix the femoral replacement prosthesis to the remaining distal femur 400. The femoral replacement prosthesis consists of the proximal femur 100, the femoral extension segment 200, and the medullary canal extension stem 300.

[0007] The eccentric fixation created by the lateral plate 500 can also make the femoral replacement prosthesis prone to instability. When the femoral resection length is too long and the distal 400mm of the femur is too short, it is inconvenient to use the lateral plate 500 for fixation.

[0008] Whether it is proximal femoral remnant or distal femoral remnant, when the length of the femoral remnant is short, the above-mentioned conventional medical methods can no longer achieve good stability of the femoral replacement prosthesis. Summary of the Invention

[0009] To improve the stability of femoral replacement prostheses, this application provides a 3D-printed, personalized subtotal artificial femoral replacement prosthesis to increase the contact length between the femoral replacement prosthesis and the osteotomized femur, thereby reducing the degree of loosening of the femoral replacement prosthesis.

[0010] This application provides a 3D-printed, personalized, subtotal artificial femoral replacement prosthesis, employing the following technical solution:

[0011] A 3D-printed, personalized subtotal artificial femoral replacement prosthesis includes:

[0012] A 3D-printed femoral segment is used to replace the portion of the femoral osteotomy. One end of the 3D-printed femoral segment is integrally formed with a short medullary needle, which is inserted into the remaining femoral medullary cavity. The short medullary needle is coaxially arranged with the 3D-printed femoral segment.

[0013] A reinforcing nail is coaxially arranged with the 3D-printed femoral segment. The reinforcing nail is used to sequentially penetrate from the proximal end or the distal end of the remaining femur into the short medullary needle and the 3D-printed femoral segment.

[0014] By adopting the above technical solution and using reinforcing nails to fix the 3D-printed femoral segment, the femoral segment prosthesis can be positioned, and it is not easy to cause eccentric positioning. Moreover, when the residual part after femoral resection is short, even if the length of the short medullary nail is short, the 3D-printed femoral segment has high stability under the action of the reinforcing nails.

[0015] Optionally, the end of the 3D-printed femoral segment away from the short medullary needle is connected to a proximal femoral segment, which is used to connect to the femoral head prosthesis, and the 3D-printed femoral segment is connected between the proximal femoral segment and the remaining distal femoral segment.

[0016] By adopting the above technical solution, during proximal femoral prosthesis replacement surgery, the proximal femur is connected to the femoral head prosthesis, and the 3D-printed femoral segment is connected between the proximal femur and the remaining distal femur. At this time, reinforcement screws need to be inserted from the distal femur into the 3D-printed femoral segment. Even if the proximal femoral defect ratio is large and the distal femur remains small, the fixation screws can still provide good support for the 3D-printed femoral segment.

[0017] Optionally, the reinforcing nail is an intramedullary nail, which is inserted retrogradely into the 3D-printed femoral segment from the remaining distal femur.

[0018] By adopting the above technical solution, the combination of intramedullary nails and 3D-printed femoral segments improves the stability of the 3D-printed femoral segments. Since intramedullary nails are commonly used medical fixation devices for fractures, this expands their applicability, eliminating the need to manufacture specialized types of fixation nails and saving costs.

[0019] Optionally, the 3D-printed femoral segment has a hollow hole at one end away from the upper femoral segment, and the intramedullary nail is inserted into the hollow hole.

[0020] By adopting the above technical solution, the hollow hole is used to accommodate the intramedullary nail, thereby reducing the operational difficulty of implanting the intramedullary nail into the 3D-printed femoral segment and facilitating the precise positioning of the intramedullary nail.

[0021] Optionally, the intramedullary nail is clearance-fitted with the hollow hole.

[0022] By adopting the above technical solution, the intramedullary nail can be easily inserted into the hollow hole.

[0023] Optionally, it also includes fixation screws and locking screws, wherein the fixation screws are inserted into both the 3D-printed femoral segment and the intramedullary nail, and the locking screws are inserted into both the intramedullary nail and the remaining distal femoral segment.

[0024] By adopting the above technical solutions, the fixation screws and locking screws further improve the stability of the 3D printed femoral segment and the intramedullary nail in fixing each other.

[0025] Optionally, the intramedullary nail has a through hole along its own axis, and the outer surface of the intramedullary nail has multiple overflow holes that communicate with the through hole. The gap between the intramedullary nail and the inner wall of the hollow hole is filled with bone cement, and the through hole is filled with bone cement.

[0026] By employing the above technical solution, when the intramedullary nail is implanted into the remaining distal femur, the through-hole is used to drain debris from the femoral medullary cavity, allowing the intramedullary nail to be successfully implanted into the distal femur and the 3D-printed femoral segment. After the fixation nail is driven into the 3D-printed femoral segment, bone cement is injected from one end of the through-hole, allowing the bone cement to drain through the overflow hole into the gap between the intramedullary nail and the inner wall of the hollow hole, thereby filling the through-hole and the hollow hole with bone cement.

[0027] Before the bone cement hardens, locking screws are driven in, so that the hardened bone cement will surround the locking screws and fixation screws, further improving the fixation effect of the locking screws and fixation screws, thereby improving the fixation effect of the intramedullary nail and the 3D printed femoral segment.

[0028] Optionally, multiple fixation screws are provided, which are spaced apart and intersected along the axial direction of the intramedullary nail; multiple locking screws are provided, which are spaced apart and intersected along the axial direction of the intramedullary nail.

[0029] By adopting the above technical solution, multiple locking screws and multiple fixing screws segmentally block the bone cement, thereby preventing the bone cement from flowing freely before solidification and improving the filling effect of the bone cement.

[0030] Optionally, the diameter of the 3D-printed femoral segment gradually increases in the direction away from the upper femoral segment, and a connecting sleeve is provided on the outer side of the 3D-printed femoral segment, with the fixing pin passing through the connecting sleeve.

[0031] By adopting the above technical solution, the diameter of the 3D printed femoral segment gradually increases in the direction away from the proximal femur, thereby adapting to the smaller proximal femur and the larger residual distal femur.

[0032] After the connecting sleeve is fitted onto the 3D-printed femoral segment, it is not easy for the connecting sleeve to slip away from the upper femoral segment. Thus, after the fixation nail connects the connecting sleeve, the 3D-printed femoral segment, and the intramedullary nail into one unit, the intramedullary nail is not easy to detach from the 3D-printed femoral segment.

[0033] In addition, because the diameter of the 3D printed femoral segment near the upper femoral segment is small, the thickness of the 3D printed femoral segment near the upper femoral segment is thinner after the through hole is opened. This makes the connection between the fixation pin and the 3D printed femoral segment less stable. The connecting sleeve is equivalent to thickening the 3D printed femoral segment, making it easier to fix the fixation pin and reducing the loosening and falling off of the fixation pin.

[0034] In summary, this application includes at least one of the following beneficial technical effects:

[0035] 1. Using reinforcing nails to fix the 3D-printed femoral segment and short medullary nails reduces the likelihood of eccentric positioning, resulting in higher positioning stability of the 3D-printed femoral segment even with limited residual femoral length.

[0036] 2. The upper femur, 3D-printed femoral segment, short medullary nail, and intramedullary nail work together to improve the applicability of the intramedullary nail. It eliminates the need to specially produce different types of fixation nails, saving costs. The fixation nails and locking nails further improve the stability of the fixation between the 3D-printed femoral segment and the intramedullary nail.

[0037] 3. After the bone cement solidifies, it wraps around the locking screws and fixing screws, further improving the fixation effect of the locking screws and fixing screws, thereby improving the fixation effect of the intramedullary nail and the 3D printed femoral segment.

[0038] 4. The connecting sleeve acts as a thickening agent for the 3D-printed femoral segment, making it easier to fix the fixation screw. In addition, because the connecting sleeve is less likely to slip away from the upper femoral segment, the intramedullary nail is less likely to detach from the 3D-printed femoral segment after the fixation screw connects the connecting sleeve, the 3D-printed femoral segment, and the intramedullary nail into one unit. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the femoral replacement prosthesis inserted into the remaining distal femur in the background art.

[0040] Figure 2 This is a schematic diagram of the structure of a femoral replacement prosthesis in the background art.

[0041] Figure 3This is a schematic diagram of the femoral replacement prosthesis in the background art, which is fixed with an external steel plate.

[0042] Figure 4 This is a schematic diagram of the structure of the 3D-printed personalized subtotal artificial femoral replacement prosthesis of Embodiment 1 of this application.

[0043] Figure 5 This is a schematic diagram of the structure of the 3D-printed femoral segment of Embodiment 1 of this application.

[0044] Figure 6 This is a top view of the 3D-printed personalized subtotal artificial femoral replacement prosthesis of Embodiment 1 of this application, used to show the AA sectional view direction.

[0045] Figure 7 yes Figure 6 Sectional view along direction AA.

[0046] Figure 8 This is a cross-sectional view of the 3D-printed personalized subtotal artificial femoral replacement prosthesis in Embodiment 2 of this application.

[0047] Explanation of reference numerals in the attached figures:

[0048] 100. Proximal femur; 200. Femoral extension; 300. Medullary canal extension stem; 400. Distal femur; 500. Lateral plate;

[0049] 1. 3D printed femoral segment; 11. Short medullary nail; 12. Hollow hole; 2. Distal femur; 3. Reinforcing nail; 31. Intramedullary nail; 311. Through hole; 312. Overflow hole; 4. Proximal femur; 5. Fixation nail; 6. Locking nail; 7. Connecting sleeve; 8. Fixation nail hole; 9. Locking nail hole; Detailed Implementation

[0050] The following is in conjunction with the appendix Figure 4-8 This application will be described in further detail.

[0051] This application discloses a 3D-printed, personalized, subtotal artificial femoral replacement prosthesis.

[0052] Example 1

[0053] Reference Figure 4 , Figure 5 The 3D-printed personalized subtotal femoral replacement prosthesis includes a 3D-printed femoral segment 1, which replaces the amputated portion of the femur. One end of the 3D-printed femoral segment 1 is connected to a short medullary nail 11, which is inserted into the medullary cavity of the remaining distal femur 2 and fixed with bone cement (not shown in the attached diagram).

[0054] Reference Figure 4 , Figure 5When there is less residual femur, the short medullary needle 11 will be shorter accordingly.

[0055] Reference Figure 6 , Figure 7 To improve the stability of the 3D-printed femoral segment 1, a reinforcing nail 3 is coaxially inserted into the 3D-printed femoral segment 1. The reinforcing nail 3 is an intramedullary nail 31, which is inserted from the remaining part of the femur into the 3D-printed femoral segment 1 to fix the 3D-printed femoral segment 1.

[0056] Reference Figure 7 Example 1 uses a bone defect disease following proximal femoral osteotomy as an example. The end of the 3D-printed femoral segment 1 furthest from the short medullary nail 11 is connected to the proximal femoral segment 4. The connection between the proximal femoral segment 4 and the 3D-printed femoral segment 1 is a conventional and mature medical procedure. The proximal femoral segment 4 is used to connect to the femoral head prosthesis. At this point, an intramedullary nail 31 needs to be inserted from the remaining distal femoral segment 2 after osteotomy into the 3D-printed femoral segment 1.

[0057] Reference Figure 5 , Figure 7 Because the intramedullary nail 31 is relatively long, a through hollow hole 12 is coaxially formed on the intramedullary nail 31 to ensure precise positioning within the 3D-printed femoral segment 1. The hollow hole 12 extends into the 3D-printed femoral segment 1. The intramedullary nail 31 is inserted into the hollow hole 12. Since some manufacturers produce intramedullary nails 31 with irregular shapes, a clearance fit is used between the intramedullary nail 31 and the hollow hole 12 to accommodate more models of intramedullary nails and to ensure better insertion into the hollow hole 12.

[0058] Intramedullary nail 31 is a commonly used medical device for treating fractures. In this embodiment, the combination of intramedullary nail 31 and 3D printed femoral segment 1 has a significant effect on treating bone defects caused by tumor osteotomy.

[0059] Reference Figure 7 A fixation nail 5 is inserted through the 3D-printed femoral segment 1, and the fixation nail 5 is also inserted into the intramedullary nail 31. The fixation nail 5 is threadedly connected to the 3D-printed femoral segment 1 and the intramedullary nail 31 respectively. In order to improve the fixation effect, two fixation nails 5 are provided in both the coronal and sagittal planes.

[0060] Reference Figure 7 A locking screw 6 is inserted through the distal femur 2 after osteotomy, and the locking screw 6 passes through the intramedullary nail 31. The locking screw 6 is threadedly connected to the remaining distal femur 2 and the intramedullary nail 31 respectively.

[0061] Because there is relatively little remaining distal femur 2, and because it is easier for the surgeon to insert locking screws 6 in the coronal plane, two locking screws 6 are placed in the coronal plane and one in the sagittal plane. The number of locking screws 6 and fixation screws 5 is adjusted according to the actual needs of the surgery.

[0062] Reference Figure 5 , Figure 7 To facilitate the insertion of the fixation screws 5 and locking screws 6, the 3D-printed femoral segment 1 and intramedullary nail 31 are each provided with corresponding fixation screw holes 8 or locking screw holes 9.

[0063] The implementation principle of Example 1 is as follows: After installing the 3D-printed femoral segment 1 and the proximal femoral segment 4 onto the missing distal femoral end 2, an intramedullary nail 31 is driven into the hollow hole 12 of the 3D-printed femoral segment 1 through the distal femoral end 2, followed by the insertion of a fixation nail 5 and a locking nail 6. The intramedullary nail 31 indirectly increases the length of the distal femoral end 2, thereby improving the stability of the femoral replacement prosthesis under the action of the intramedullary nail 31, the fixation nail 5, and the locking nail 6.

[0064] Example 2

[0065] Reference Figure 8 The difference between Example 2 and Example 1 is that the intramedullary nail 31 has multiple overflow holes 312 on its body.

[0066] Reference Figure 8 In order to facilitate the removal of debris from the medullary cavity during routine fracture repair, the intramedullary nail 31 has a through hole 311 coaxially extending to both ends of the intramedullary nail 31. The overflow hole 312 is connected to the through hole 311.

[0067] After the fixation nail 5 is inserted into the 3D-printed femoral segment, the debris in the through hole 311 is first extracted from the end of the intramedullary nail 31 near the distal end 2 of the femur. Then, bone cement is injected into the through hole 311. The bone cement overflows into the hollow hole 12 through the overflow hole 312. When the bone cement fills the hollow hole 12 and the through hole 311, the injection is stopped. The bone cement is not shown in the attached figure.

[0068] Before the bone cement hardens, locking screws 6 are driven in. After the bone cement hardens, it surrounds the fixation screws 5 and 6, thereby improving their stability. The bone cement fills the gaps in the intramedullary nail 31 and the hollow hole 12, thereby increasing the strength of the intramedullary nail 31 and the 3D-printed femoral segment 1.

[0069] The staggered fixing pins 5 and locking pins 6 act as segmented barriers for the bone cement, thereby reducing the possibility of the bone cement flowing freely and improving the filling effect of the hollow holes 12 and through holes 311 after the bone cement solidifies.

[0070] Reference Figure 8 Furthermore, because the size of the proximal femur 4 is smaller than that of the distal femur 2 in actual surgery, the diameter of the 3D-printed femoral segment 1 gradually increases along the direction closer to the distal femur 2. As a result, the outer surface of the 3D-printed femoral segment 1 is conical.

[0071] Reference Figure 8 A connecting sleeve 7 is fitted on the outer side of the 3D-printed femoral segment 1, and a fixing nail 5 is inserted into the connecting sleeve 7.

[0072] Due to the conical shape of the 3D-printed femoral segment 1, the sliding of the connecting sleeve 7 toward the distal end of the femur 2 is restricted. Thus, after the fixing nail 5 connects the connecting sleeve 7, the 3D-printed femoral segment 1, and the intramedullary nail 31 into one unit, the possibility of the intramedullary nail 31 detaching from the 3D-printed femoral segment 1 is reduced.

[0073] Because the diameter of the 3D-printed femoral segment 1 near the upper femoral segment 4 is small, the thickness of the 3D-printed femoral segment 1 near the upper femoral segment 4 is relatively thin after the through hole 311 is opened. This makes the connection between the fixation nail 5 and the 3D-printed femoral segment 1 less stable. The connecting sleeve 7 thickens the 3D-printed femoral segment 1, making it easier to fix the fixation nail 5. In addition, the connecting sleeve 7 makes it less likely for bone cement to flow out of the 3D-printed femoral segment 1 from the hole of the fixation nail 5.

[0074] The implementation principle of Example 2 is as follows: Bone cement is injected into the through hole 311 and the hollow hole 12, thereby improving the fixation effect of the femoral replacement prosthesis. The setting of the connecting sleeve 7 has two functions: firstly, it thickens the 3D printed femoral segment 1, making it easier to fix the fixation nail 5 and reducing the loosening and falling off of the fixation nail 5; secondly, under the restriction of the conical outer surface of the 3D printed femoral segment 1, it has the effect of preventing the intramedullary nail 31 from falling off the 3D printed femoral segment 1; and thirdly, it reduces the possibility of bone cement flowing out of the 3D printed femoral segment 1 from the hole of the fixation nail 5.

[0075] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A 3D printed personalized custom-fit sub-total hip prosthetic femoral replacement prosthesis, characterized in that, The utility model relates to a kind of 3D printing femoral segments (1) for replacing femoral osteotomy part, one end of the 3D printing femoral segments (1) is integrally formed with short intramedullary pin (11), the short intramedullary pin (11) is inserted in residual femoral medullary cavity, the short intramedullary pin (11) is coaxially arranged with the 3D printing femoral segments (1);Reinforcing nail (3) is coaxially arranged with the 3D printing femoral segments (1), the reinforcing nail (3) is used for residual femoral distal end (2) sequentially into the short intramedullary pin (11) and the 3D printing femoral segments (1); The end of the 3D printing femoral segments (1) away from short intramedullary pin (11) is connected with femoral upper segment (4), and the femoral upper segment (4) is used to be connected with femoral head prosthesis, and the 3D printing femoral segments (1) is connected between the femoral upper segment (4) and residual femoral distal end (2); The reinforcing nail (3) is intramedullary nail (31), and the intramedullary nail (31) is inserted into the 3D printing femoral segments (1) from residual femoral distal end (2) in reverse direction; It further includes fixing nail (5) and locking nail (6), the fixing nail (5) is simultaneously arranged in the 3D printing femoral segments (1) and the intramedullary nail (31), and the locking nail (6) is simultaneously arranged in the intramedullary nail (31) and residual femoral distal end (2); The fixing nail (5) is provided with a plurality of, and the plurality of fixing nails (5) is spaced apart and is arranged in cross along the axial direction of the intramedullary nail (31), and the locking nail (6) is provided with a plurality of, and the plurality of locking nails (6) is spaced apart and is arranged in cross along the axial direction of the intramedullary nail (31); The diameter of the 3D printing femoral segments (1) gradually increases along the direction away from the femoral upper segment (4), and the 3D printing femoral segments (1) is provided with connecting sleeve (7) outside, and the fixing nail (5) is arranged in the connecting sleeve (7). The end of the 3D printing femoral segments (1) away from the femoral upper segment (4) is provided with hollow hole (12), and the intramedullary nail (31) is arranged in the hollow hole (12).

2. The 3D-printed personalized custom-fit hemi-prosthetic femoral replacement prosthesis according to claim 1, characterized in that, The intramedullary nail (31) is in clearance fit with the hollow hole (12).

3. The 3D printed individually customized hemi-resurfacing femoral replacement prosthesis according to claim 2, characterized in that, The intramedullary nail (31) is provided with through hole (311) along the axial direction thereof, the outer surface of the intramedullary nail (31) is provided with a plurality of overflow holes (312), the overflow holes (312) are communicated with the through hole (311), the gap between the intramedullary nail (31) and the inner wall of the hollow hole (12) is filled with bone cement, and the through hole (311) is filled with bone cement.

4. The 3D-printed personalized custom-fit hemi-prosthetic femoral replacement prosthesis according to claim 2, characterized in that, ​

Images