A prosthetic system for minimally invasive femoral head replacement

Abstract

The application discloses a prosthesis system for minimally invasive femoral head replacement, which comprises a bone cutting assembly, a prosthesis, an extension rod, a guide frame and a locking nail. In the operation, only a small opening is needed on the lateral side of the femoral neck, and then a channel is established, and the prosthesis is implanted in the channel, so that the degree of trauma, the operation time and the blood loss are greatly reduced. A detachable extension rod is arranged on the implanted prosthesis, and after the extension rod is positioned by cooperating with the guide frame, the extension rod can guide the path of the locking nail, so that the locking nail is connected with the prosthesis, and is fixed with the large and small trochanters of the patient, so that the prosthesis can be combined with the relatively hard bone and the surface layer of the femoral neck to achieve stable combined support and avoid loosening of the prosthesis.

Description

Technical Field

[0001] This invention relates to the field of femoral head replacement surgery, and more particularly to a prosthesis system for minimally invasive femoral head replacement surgery. Background Technology

[0002] Avascular necrosis of the femoral head is a disease caused by interruption or damage to the blood supply to the femoral head, leading to the death of bone cells and bone marrow components, followed by repair, and ultimately resulting in changes in the structure of the femoral head, femoral head collapse, and joint dysfunction. The usual treatment is total hip replacement surgery, which involves implanting an artificial prosthesis to replace the diseased femoral head, restoring the normal anatomical relationship of the hip joint, improving joint mobility, and relieving pain.

[0003] Traditional hip replacement surgery, involving either stemmed or sessile artificial hip joints, commonly involves resection sites such as... Figure 1 As shown, the procedure mainly involves directly removing the femoral neck 013 obliquely along the base of the femoral neck 011 (as shown by the resection line L1), along with the diseased or worn femoral head 012. The femoral medullary cavity is then emptied and enlarged before implanting and fixing an artificial hip joint stem, which is then combined with an artificial femoral head 02. Both US Patent US5163961A and Chinese Patent CN00244070.9 clearly disclose the removal of the diseased or worn femoral head 012 from the head and neck, and the fixing of a cover 03 to the remaining femoral neck 011 with bolts, indicating that these are indeed very common surgical methods.

[0004] However, the above-mentioned surgical methods have the following drawbacks in practical applications:

[0005] 1) Because stemmed total hip replacement surgery requires extensive bone and bone marrow removal, extraction and reshaping, the degree of surgical trauma, operation time and blood loss are greatly increased. The severed posterolateral muscle group is prone to dislocation, which greatly increases the overall surgical risk.

[0006] 2) Due to the removal or excision of large areas of bone (such as the entire femoral neck), the accuracy of related dimensions is difficult to control. This makes it difficult to maintain accurate matching between the surface of the stem of the handle artificial hip joint or the inner surface of the cover of the handleless artificial hip joint and the surface of the installed bone. Not only can such artificial hip joints not achieve stable bonding and support from the relatively hard bone or bone neck surface, but stress concentration is also likely to occur, which directly and seriously affects the surgical results and the quality of postoperative recovery.

[0007] 3) Since all kinds of artificial joints have their service life, after long-term use, complications such as wear, loosening and sinking often occur, requiring revision surgery. The traditional stemmed artificial hip replacement surgery has a large excision site and trauma in the initial surgery, so when revision surgery is needed, the entire femur is usually enlarged and deepened along with the cavity. This inevitably increases the trauma and difficulty of the surgery. Since the wear cycle of the prosthesis is about 30 years, it is not friendly to young patients in the early stage, and there are almost no good revision methods after damage.

[0008] 4) In traditional stemless total hip arthroplasty, the location of the bone resection is not scientifically and completely defined in terms of measurement and positioning methods and procedures. Therefore, the surgeon's experience is often required to determine the location of the femoral neck resection. The postoperative results obtained by different surgeons also vary significantly, making it difficult to ensure the consistency of the surgery. As a result, the success or failure of the surgery cannot be simulated and evaluated in advance, making it more difficult for patients to prepare psychologically before the surgery.

[0009] 5) such as Figure 1 As shown, since the cover 03 of the handleless artificial hip joint is obliquely positioned on the cutting plane of the parallel resection line L1, and the surface of its femoral neck 011 cannot be guaranteed to form a continuous tight fit with the inner surface of the cover 03, the joint stress cannot be evenly distributed and transmitted, which makes it easy to generate stress concentration in practical applications and affect the durability of its overall structure.

[0010] Given the aforementioned drawbacks of common hip replacement surgeries, there is a need to develop research and improvement inventions that address these shortcomings. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a prosthesis system for minimally invasive femoral head replacement surgery that can reduce the trauma of femoral head replacement surgery and improve the stability of prosthesis implantation.

[0012] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0013] A prosthetic system for minimally invasive femoral head replacement surgery, characterized in that it comprises:

[0014] A bone-cutting component for creating a channel in the direction of the femoral neck, wherein a first end of the channel penetrates the surface of the femoral head and a second end penetrates in the opposite direction;

[0015] A prosthesis for filling a channel, having a femoral head prosthesis at a first end of the prosthesis, the prosthesis having an inherent radially penetrating pin hole, the femoral head prosthesis portion protruding from the first end of the channel;

[0016] The extension rod is detachably fixed to the second end of the prosthesis;

[0017] A guide frame includes a positioning sleeve for positioning an extension rod and a guide sleeve for guiding a locking pin. The positioning sleeve, after engaging with the extension rod, enables rotational and axial positioning of the extension rod. After the extension rod is positioned, the guide sleeve can point towards the pin hole.

[0018] The locking pin passes through the pin hole on the prosthesis via a guide sleeve and is fixed to the prosthesis. Both ends of the locking pin can be connected and fixed to the cortical layer of the greater trochanter and lesser trochanter of the femur.

[0019] A further technical solution is that the locking pin is a hollow screw structure with external threads.

[0020] A further technical solution includes:

[0021] The guide pin is inserted through the guide sleeve, passes through the nail hole from the greater trochanter of the femur and penetrates the cortical layer of the lesser trochanter of the femur;

[0022] The locking pin is fitted over the guide pin and driven in along the guide pin; the inner hole at the rear end of the locking pin has a non-circular structure.

[0023] A swivel handle is fitted over the guide pin, and its front end has a rotating head that engages with the inner hole of the locking pin. The locking pin is driven in by the rotation of the swivel handle.

[0024] A further technical solution is that the guide sleeve, locking pin, and pin hole are each provided in two sets, and the two sets are parallel and located in the same plane.

[0025] A further technical solution is that the distance between the two sets of nail holes is 5~30mm, and the diameter of the nail holes is 3~8mm.

[0026] A further technical solution is that the rear end of the positioning sleeve has a notch, and the outer wall of the extension rod has a protruding insert, which can be embedded in the notch and protrude radially out of the notch.

[0027] A further technical solution is that the guide frame also has a pointer that can be rotated and locked.

[0028] A further technical solution is that the prosthesis is a hollow cage-like structure with perforated outer walls or a hollow solid structure with solid outer walls.

[0029] A further technical solution is that the outer wall of the prosthesis has multiple barbed structures to prevent the prosthesis from moving outward axially.

[0030] A further technical solution is that the femoral head prosthesis has a ball head integrally formed with the prosthesis, an outer cup is provided outside the ball head, and a silicone column is provided between the ball head and the outer cup.

[0031] The beneficial effects of adopting the above technical solution are as follows:

[0032] Using this component for femoral head replacement surgery only requires making a small incision on the outside of the femoral neck, then creating a channel, and inserting the prosthesis into the channel. There is no need to remove the femoral head and femoral neck, nor to empty the femoral medullary cavity, which greatly reduces the degree of trauma, operation time and blood loss.

[0033] A detachable extension rod is installed on the implanted prosthesis. After the extension rod is positioned in conjunction with the guide frame, it can guide the insertion path of the locking screw. After the locking screw is connected to the prosthesis, it is fixed to the patient's greater and lesser trochanters, so that the prosthesis can combine with the relatively hard bone and the surface of the femoral neck to achieve a stable combination and support, and prevent the prosthesis from loosening.

[0034] Minimally invasive femoral head replacement surgery performed using this component allows for effective revision after prosthesis wear, making it more suitable for patients with femoral head problems. Attached Figure Description

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0036] Figure 1 This refers to the cutting location in existing femoral head replacement surgery techniques.

[0037] Figure 2 This is a schematic diagram of the components disclosed herein in use during surgery (the osteotomy component is not shown).

[0038] Figure 3 This is an exploded view of the components disclosed herein;

[0039] Figure 4 This is a schematic diagram of the positioning sleeve and extension rod locking part disclosed herein;

[0040] Figure 5 This is the first form of the prosthesis disclosed herein;

[0041] Figure 6 This is the second form of the prosthesis disclosed herein;

[0042] Figure 7 This is the third type of prosthesis disclosed in this publication;

[0043] Figure 8 This is the fourth form of the publicly disclosed prosthesis. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0046] like Figures 1-4 As shown, this disclosure discloses a prosthetic system for minimally invasive femoral head replacement surgery, including an osteotomy assembly, a prosthesis 20, an extension rod 30, a guide frame 40, and a locking pin 50.

[0047] Osteotomy components are used to create a channel along the femoral neck. Osteotomy components for constructing channels in orthopedics are existing technology and come in various forms. Tools such as bone drills, circumferential cutters, and curettes can be used to create the channel. Ultimately, the first end of the channel penetrates the surface of the femoral head, and the second end penetrates in the opposite direction.

[0048] The prosthesis 20 is used to fill the channel. At the first end of the prosthesis 20 is a femoral head prosthesis 21. The prosthesis 20 has a radially penetrating pin hole. The femoral head prosthesis 21 protrudes from the first end of the channel and contacts the acetabulum. The extension rod 30 is detachably fixed to the second end of the prosthesis 20. The specific connection method can be a threaded connection or other quick-release structure.

[0049] The guide frame 40 is located on the outside of the affected limb. The guide frame 40 has a positioning sleeve 41 for positioning the extension rod 30 and a guide sleeve 42 for guiding the locking pin 50. Specifically, there is a notch 411 at the rear end of the positioning sleeve 41, and a protruding insert 301 on the outer wall of the extension rod 30. The insert 301 can be embedded in the notch 411 and protrude radially out of the notch 411, so that the positioning sleeve 41 can rotate and position the extension rod 30 axially after cooperating with the extension rod 30. After the extension rod 30 (i.e., the prosthesis 20) is positioned, the guide sleeve 42 can point to the pin hole.

[0050] The locking screw 50 passes through the screw hole on the prosthesis 20 via the guide sleeve 42 and is fixed to the prosthesis 20. Both ends of the locking screw 50 can connect and be fixed to the cortical layer of the greater and lesser trochanters of the femur. The locking screw 50 can be a hollow screw structure with external threads. The screw hole on the prosthesis can be a smooth hole or a threaded hole. The external threads on the locking screw 50 are mainly to increase the friction between the bone and the locking screw 50, thereby increasing the bone's holding force on the locking screw 50.

[0051] A prosthetic system for minimally invasive femoral head replacement surgery further includes components for installing locking screws 50, specifically a guide pin 51 and a rotating handle 52. The guide pin 51 is inserted via a guide sleeve 42, passing through a screw hole in the greater trochanter of the femur and penetrating the cortical layer of the lesser trochanter. The locking screw 50 is fitted over the guide pin 51 and driven in along its guide; the rear end of the locking screw 50 has a non-circular inner hole. The rotating handle 52 is fitted over the guide pin 51, and its front end has a rotating head 521 that engages with the inner hole of the locking screw 50. The locking screw 50 is driven in by rotating the handle 52. This structure allows the locking screw 50 to be of sufficient length to meet surgical requirements, eliminating the need for subsequent trimming of excess length and improving surgical efficiency.

[0052] In this disclosed prosthesis system for minimally invasive femoral head replacement surgery, the guide sleeve 42, locking screws 50, and screw holes are provided in two sets, with the two sets parallel and located in the same plane, to increase the connection length between the locking screws 50 and the bone. Furthermore, the distance between the two sets of screw holes is 5-30 mm, and the diameter of the screw holes is 3-8 mm, ensuring that the locking screws 50 firmly connect the prosthesis 20 to the bone.

[0053] The procedure for using this prosthetic system in minimally invasive femoral head replacement surgery is as follows:

[0054] 1. Establish a channel by traction on the affected leg to open the acetabular space. Based on the preoperative planning data, locate the area with dense sequestra. Point the tip of the guide needle towards the area with dense sequestra and insert the guide needle along the femoral neck from the cortex below the greater trochanter. After confirming the position of the guide needle, use an osteotomy component (such as a guide trephine) to establish a channel in the direction of the femoral neck, so that the second end of the channel penetrates the surface of the greater trochanter of the femur and the first end penetrates the cartilage layer of the femoral head.

[0055] 2. Assembly: Connect the prosthesis 20 to the extension rod 30, and connect the extension rod 30 to the positioning sleeve 41 on the guide frame 40, so that the guide sleeve 42 on the guide frame 40 points to the nail hole on the prosthesis 20;

[0056] 3. Implant prosthesis 20. Insert prosthesis 20 into the channel and, under fluoroscopic guidance, insert prosthesis 20 to the appropriate depth so that the femoral head prosthesis 21 protrudes from the first end of the channel and contacts the acetabulum.

[0057] 4. Adjust the position and rotate the whole structure (including the prosthesis 20, extension rod 30 and guide frame 40) so that the outer guide sleeve 42 points towards the patient's greater trochanter of the femur;

[0058] 5. Insert the locking pin 50. First, insert the guide pin 51 (Kirschner wire can be used) along the guide sleeve 42 from the greater trochanter of the femur. Under fluoroscopic guidance, make the front end of the guide pin 51 pass through the lesser trochanter of the femur. Then, insert the locking pin 50 along the guide pin 51. Next, put the handle 52 on the guide pin 51 and insert the rotating head 521 of the handle 52 into the inner hole at the rear end of the locking pin 50. By rotating the handle 52, the locking pin 50 can be driven to rotate and enter, so that it passes through the pin hole on the prosthesis 20 and is fixed to the prosthesis 20. Under fluoroscopic guidance, make the front end of the locking pin 50 connect and fix to the cortical layer of the lesser trochanter of the femur.

[0059] 6. Remove unnecessary parts, and take off the guide pin 51, the handle 52, the extension rod 30, and the guide frame 40;

[0060] 7. Sutured, surgery complete.

[0061] Using this component for femoral head replacement surgery only requires a small incision on the outside of the femoral neck, then creating a channel to implant the prosthesis 20. There is no need to remove the femoral head and femoral neck, nor to empty the femoral medullary cavity, which greatly reduces the degree of trauma, operation time and blood loss.

[0062] A detachable extension rod 30 is installed on the implanted prosthesis 20. After the extension rod 30 is positioned in conjunction with the guide frame 40, it can guide the insertion path of the locking pin 50. After the locking pin 50 connects to the prosthesis 20, it is fixed to the patient's greater trochanter and lesser trochanter, so that the prosthesis 20 can combine with the relatively hard bone and the surface of the femoral neck to achieve a stable combination support and prevent the prosthesis 20 from loosening.

[0063] Minimally invasive femoral head replacement surgery performed using this component allows for effective revision after the prosthesis wears down to 20mm, making it more suitable for patients with femoral head problems.

[0064] In this disclosed prosthetic system for minimally invasive femoral head replacement surgery, the guide frame 40 also has a rotatable and lockable pointer 60. The pointer 60 corresponds to a dial. Before surgery, the surgeon pre-adjusts the angle between the pointer 60 and the guide frame 40 based on the angle formed by the greater and lesser trochanters and the femoral shaft, using the femoral shaft as a reference. When the pointer 60 is parallel to the femoral shaft, it is determined that the guide sleeve 42 on the guide frame 40 is pointing to the position of the greater trochanter. This facilitates the operation of the aforementioned surgical step 4. This function combines the precision preoperative planning technology advocated by modern medicine, which can reduce the number of fluoroscopy sessions.

[0065] This disclosure includes a prosthetic system for minimally invasive femoral head replacement surgery, such as... Figure 5-8 As shown, the prosthesis 20 can be made of metallic materials such as pure titanium, stainless steel, cobalt-based alloys, titanium-based alloys, magnesium-titanium alloys, etc., or non-degradable polymer materials such as PA plastics, polyethylene (PE), etc.

[0066] The prosthesis, containing the femoral head, is inserted through a femoral neck tunnel to reduce wear and tear between the femoral head and acetabulum. Figures 5-8 As shown, the femoral head prosthesis is either bipolar or unipolar. The femoral head prosthesis and the femoral neck prosthesis are an integral structure. The femoral neck prosthesis is hollow and may have N irregular holes on its outer wall.

[0067] For young, highly active patients, the prosthesis 20 can preferably be a hollow, perforated cage-like structure, allowing for the placement of autologous bone grafts or artificial bone, promoting regional bone growth, maximizing femoral viability, and increasing the holding force between the bone and the implant. This is suitable for young patients requiring secure fixation of the prosthesis 20. Furthermore, the outer wall of the prosthesis 20 can have multiple barbed structures 22 to prevent axial movement of the prosthesis 20. The hard bone of the inner wall of the channel restricts the barbed structures 22, enhancing the stability of the prosthesis 20 implantation.

[0068] For older patients with cancellous osteoporosis, the preferred form of prosthesis 20 is a hollow structure with a solid outer wall. The cageless form of prosthesis 20 is more suitable for older patients with cancellous osteoporosis.

[0069] In addition, the femoral head prosthesis 21 has a ball head integrally formed with the prosthesis 20, an outer cup outside the ball head, and a silicone pillar 201 between the ball head and the outer cup. Specifically, there is a groove at the front end of the ball head, and the silicone pillar fills the groove and protrudes out of the groove to contact the outer cup. The silicone pillar has axial compression, which can buffer and reduce wear on the femoral head prosthesis 21. This is more suitable for young patients with high activity levels and extends the service life of the femoral head prosthesis 21.

[0070] The above are merely preferred embodiments of the present invention. Any simple modifications, variations, and equivalent substitutions made by any person based on the content of the present invention shall fall within the protection scope of the present invention.

Claims

1. A prosthetic system for minimally invasive femoral head replacement surgery, characterized in that, include: A bone-cutting component for creating a channel in the direction of the femoral neck, wherein a first end of the channel penetrates the surface of the femoral head and a second end penetrates in the opposite direction; The prosthesis (20) is used to fill the channel and has a femoral head prosthesis (21) at the first end of the prosthesis (20), the prosthesis (20) having a radially penetrating pin hole, the femoral head prosthesis (21) partially protruding from the first end of the channel; The extension rod (30) is detachably fixed to the second end of the prosthesis (20); The guide frame (40) has a positioning sleeve (41) for positioning the extension rod (30) and a guide sleeve (42) for guiding the locking pin (50). The positioning sleeve (41) has a notch (411) at its rear end. The extension rod (30) has a protruding insert (301) on its outer wall. The insert (301) can be inserted into the notch (411) and protrude radially out of the notch (411). After the positioning sleeve (41) cooperates with the extension rod (30), it can rotate and position the extension rod (30) axially. After the extension rod (30) is positioned, the guide sleeve (42) can point towards the pin hole. The locking pin (50) passes through the pin hole on the prosthesis (20) via the guide sleeve (42) and is fixed to the prosthesis (20). Both ends of the locking pin (50) can be connected and fixed to the cortical layer of the greater trochanter and lesser trochanter of the femur.

2. The prosthetic system for minimally invasive femoral head replacement surgery according to claim 1, characterized in that, The locking pin (50) is a hollow screw structure with external threads.

3. The prosthetic system for minimally invasive femoral head replacement surgery according to claim 2, characterized in that, Also includes: The guide pin (51) is inserted through the guide sleeve (42), passes through the nail hole from the greater trochanter of the femur and penetrates the cortical layer of the lesser trochanter of the femur; The locking pin (50) is fitted over the guide pin (51) and driven in along the guide pin (51). The inner hole at the rear end of the locking pin (50) has a non-circular structure. The handle (52) is fitted over the guide pin (51), and its front end has a rotating head (521) that fits into the inner hole of the locking pin (50). The locking pin (50) is driven into the hole by the rotation of the handle (52).

4. The prosthetic system for minimally invasive femoral head replacement surgery according to claim 1, characterized in that, The guide sleeve (42), locking pin (50) and pin hole are provided in two sets, and the two sets are parallel and located in the same plane.

5. A prosthetic system for minimally invasive femoral head replacement surgery according to claim 4, characterized in that, The distance between the two sets of nail holes is 5~30mm, and the diameter of the nail holes is 3~8mm.

6. The prosthetic system for minimally invasive femoral head replacement surgery according to claim 1, characterized in that, The guide frame (40) also has a pointer (60) that can be rotated and locked.

7. A prosthetic system for minimally invasive femoral head replacement surgery according to claim 1, characterized in that, The prosthesis (20) is a hollow cage-like structure with perforated outer walls or a hollow solid structure with solid outer walls.

8. A prosthetic system for minimally invasive femoral head replacement surgery according to claim 1, characterized in that, The outer wall of the prosthesis (20) has multiple barbed structures (22) to prevent the prosthesis (20) from moving outward axially.

9. A prosthetic system for minimally invasive femoral head replacement surgery according to claim 1, characterized in that, The femoral head prosthesis (21) has a ball head integrally formed with the prosthesis (20), an outer cup outside the ball head, and a silicone column (201) between the ball head and the outer cup.

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