Minimally invasive implantation of a partial surface femoral head joint prosthesis

Abstract

The utility model discloses a kind of minimally invasive implant artificial partial surface femoral head joint prosthesis, comprising: umbrella handle;Cylinder is sleeved on umbrella handle and is movably connected with it;First support prosthesis is sleeved on umbrella handle and is located above cylinder, with multiple first umbrella leaves in fan shape;Second support prosthesis is sleeved on umbrella handle and is located above cylinder, with multiple second umbrella leaves in fan shape being set in multiple first umbrella leaves dislocation;Wherein, multiple first umbrella leaves and multiple second umbrella leaves can be opened to complete umbrella-shaped joint prosthesis by relative umbrella handle under the impetus of cylinder.The utility model head joint prosthesis, can replace cartilage and subchondral bone of femoral head necrosis area, form good mechanical support, relieve patient discomfort, weight bearing with prosthesis, reduce femoral head endosteal bone weight bearing, slow down even reverse the progress of femoral head necrosis, can reach minimally invasive artificial joint partial replacement effect, reduce surgical trauma.

Description

Technical Field

[0001] This utility model relates to the field of medical technology, and in particular to a minimally invasive implantable femoral head joint prosthesis. Background Technology

[0002] Avascular necrosis of the femoral head is a common bone and joint disease. It can be caused by factors such as alcoholism, hip trauma, and the use of steroid medications. It commonly affects young and middle-aged patients, and after onset, it causes severe symptoms such as hip pain, limping, and leg length discrepancy, making it impossible for patients to live and work normally, resulting in a high disability rate. Currently, treatment for early-stage avascular necrosis of the femoral head mainly involves medication, using crutches or wheelchairs to reduce weight-bearing on the affected limb, suppressing pain symptoms, and slowing disease progression. For patients with mid-to-late-stage avascular necrosis of the femoral head, drug treatment is ineffective, and total hip replacement surgery is the only treatment option.

[0003] The hip joint consists of a spherical femoral head and a ball-and-socket acetabulum. Daily hip movements are achieved through the rotation of the femoral head within the acetabulum. Avascular necrosis of the femoral head occurs when the blood vessels supplying the femoral head are blocked or damaged due to the aforementioned reasons, leading to insufficient blood supply. Combined with the daily weight-bearing capacity of the body, the subchondral bone in the weight-bearing area of ​​the femoral head is prone to necrosis and bone resorption. Without the support of the underlying bone, the necrotic cartilage collapses under weight, causing the femoral head to lose its spherical shape. This results in hip pain during rotation within the acetabulum. Currently, the most effective treatment for avascular necrosis of the femoral head is total hip replacement, which involves replacing the entire femoral head with an artificial ball and acetabulum.

[0004] Currently, the staging system for avascular necrosis of the femoral head is the Association Research Circulation Osseous (ARCO) system: Stage 1: MRI shows a low signal band around the necrotic area, bone scan shows a cold area, and X-ray plate shows no abnormalities; Stage 2: X-ray plate or CT shows bone sclerosis, local osteoporosis or cystic changes, but there is no evidence of subchondral fracture, necrotic fracture or flattening of the femoral head articular surface; Stage 3A: X-ray plate or CT shows subchondral fracture, necrotic fracture and / or flattening of the femoral head articular surface, and femoral head collapse ≤2 mm; Stage 3B: X-ray plate or CT shows subchondral fracture, necrotic fracture and / or flattening of the femoral head articular surface, and femoral head collapse >2 mm; Stage 4: X-ray plate shows hip osteoarthritis with joint space narrowing, acetabular changes and destruction.

[0005] Treatment for avascular necrosis of the femoral head is primarily based on three principles: increasing blood supply to the femoral head, reducing weight-bearing on the femoral head, and inhibiting bone resorption. Treatment is divided into conservative and surgical approaches.

[0006] Conservative treatment primarily reduces the weight-bearing load on the femoral head, such as long-term use of crutches and wheelchairs, supplemented by medication to inhibit bone resorption. The effects of conservative treatment are relatively weak; it can slow the progression to some extent, but the possibility of reversing the progression of femoral head necrosis (i.e., stopping the necrosis and repairing previously necrotic lesions) is very small.

[0007] Surgical treatments mainly fall into two categories: reconstructive surgery that preserves the patient's own femoral head and total hip replacement. Femoral head-preserving surgeries include core decompression, osteotomy, bone grafting with or without blood supply, and tantalum rod implantation. These are suitable for early-stage (ARCO stage 1) or mid-stage (ARCO stage 2-3B) femoral head necrosis, with necrosis exceeding 15% of the femoral head. Core decompression involves drilling a hole within the femoral head to increase blood circulation in the necrotic area, thereby inhibiting bone necrosis or promoting regeneration. Osteotomy involves cutting the femoral head and rotating it to place the undisturbed portion in the weight-bearing area, which can alleviate symptoms to some extent. Bone grafting and tantalum rod implantation involve drilling a hole within the femoral head, removing necrotic bone tissue, implanting new bone to fill the necrotic area, and inserting a bone rod or tantalum rod to provide mechanical support to the collapsed area of ​​the femoral head. These surgeries can, to some extent, postpone total hip replacement. However, these surgeries all rely on supporting the necrotic subchondral bone to maintain the weight-bearing function of the overlying cartilage. They do not directly repair or replace the subchondral bone and cartilage in the necrotic area of ​​the femoral head. Therefore, as the disease progresses and weight-bearing continues in the necrotic area of ​​the femoral head, the patient's own subchondral bone continues to suffer from ischemic necrosis. This gradually increases in size, leading to insufficient support and rendering these surgeries ineffective. Cartilage collapse occurs, further damaging the contralateral acetabular cartilage, progressing to stage 4, at which point total hip replacement is the only option. Most of these surgeries are open surgeries; only core decompression is a minimally invasive procedure. However, this surgery only involves drilling holes in the bone to increase blood circulation in the necrotic area of ​​the femoral head, without providing mechanical support to the collapsed bone. For severe femoral head collapse (ARCO stage 4), with significant loss of joint function or moderate to severe pain, total hip replacement is the only option.

[0008] Currently, all total hip replacement surgeries are open surgeries, requiring an incision of more than 10 centimeters. For obese patients, the incision can be more than 20 centimeters long. Inside the incision, it is also necessary to cut the muscles and joint capsule behind the hip joint, and to remove the femoral head and femoral medullary cavity, all of which can lead to significant surgical bleeding and postoperative complications such as leg muscle weakness and dislocation of the artificial hip joint.

[0009] In summary, since the pathological manifestations of femoral head necrosis are mainly in the weight-bearing area of ​​the femoral head (above the femoral head), and given the limitations of current treatment methods, the current treatment principle is to preserve as much of the patient's own non-necrotic femoral head as possible through partial femoral head replacement. This aims to slow down bone collapse by providing mechanical support to the necrotic area, thereby delaying the need for total hip replacement and minimizing patient symptoms and improving function. However, because most current surgeries are open surgeries, they cause significant surgical trauma to the patient and are highly prone to surgical failure or postoperative complications. Summary of the Invention

[0010] The purpose of this invention is to solve the above-mentioned problems and provide a minimally invasive implantable artificial femoral head joint prosthesis that can replace the cartilage and subchondral bone in the necrotic area of ​​the femoral head, form good mechanical support, relieve patient discomfort, bear weight with the prosthesis, reduce the load on the bone inside the femoral head, slow down the progression of femoral head necrosis, achieve the effect of minimally invasive artificial joint replacement, and reduce surgical trauma.

[0011] To achieve the above-mentioned objectives of this utility model, this utility model provides a minimally invasive implantable artificial femoral head joint prosthesis, comprising: an umbrella handle; a cylinder fitted onto and movably connected to the umbrella handle; a first support prosthesis fitted onto the umbrella handle and located above the cylinder, having a plurality of fan-shaped first umbrella blades; and a second support prosthesis fitted onto the umbrella handle and located above the cylinder, having a plurality of fan-shaped second umbrella blades offset from the plurality of first umbrella blades; wherein the plurality of first umbrella blades and the plurality of second umbrella blades can be opened relative to the umbrella handle and assembled into a complete umbrella-shaped joint prosthesis under the push of the cylinder.

[0012] Preferably, the first support prosthesis further includes: a first connecting seat installed at the top of the umbrella handle, wherein the plurality of first umbrella blades are circumferentially spaced along the first connecting seat; a first sleeve fitted on the umbrella handle and movable relative to it; and a plurality of first umbrella ribs, one end of which is connected to the back of the corresponding first umbrella blade and the other end of which is connected to the corresponding position of the first sleeve.

[0013] Preferably, the first umbrella rib is hinged to the first sleeve and the first umbrella blade, respectively.

[0014] Preferably, the second support prosthesis further includes: a second connecting seat mounted on the umbrella handle, wherein the plurality of second umbrella blades are distributed circumferentially at intervals along the second connecting seat; a second sleeve fitted on the umbrella handle and movable relative to it; and a plurality of second umbrella ribs, one end of which is connected to the back of the corresponding second umbrella blade and the other end of which is connected to the corresponding position of the second sleeve.

[0015] Preferably, the second umbrella rib is hinged to the second sleeve and the second umbrella blade respectively.

[0016] Preferably, the second sleeve is located below the first sleeve.

[0017] Preferably, the length of the second umbrella rib is less than or equal to the length of the first umbrella rib.

[0018] Preferably, the cylinder is threadedly connected to the umbrella handle.

[0019] Preferably, it also includes a tail cap that is threaded to the lower end of the umbrella handle.

[0020] Preferably, it also includes a top cover fixedly connected to the top of the umbrella handle.

[0021] Compared with existing technologies, the minimally invasive implantable femoral head joint prosthesis of this invention has the following advantages:

[0022] This invention relates to a minimally invasive implantable artificial femoral head joint prosthesis with a simple structure and convenient use. It can replace the cartilage and subchondral bone in the necrotic area of ​​the femoral head, providing good mechanical support and replacing the necrotic cartilage on the surface, thus alleviating the patient's symptoms. It can preserve most of the non-necrotic femoral head and use the prosthesis to bear weight. Through the umbrella-shaped structure design, the load-bearing stress is concentrated on the handle and directly transmitted to the femoral shaft, reducing the load on the bone within the femoral head. By strengthening the subchondral bone area through bone grafting within the bone tunnel, the progression of femoral head necrosis is slowed down, achieving the effect of minimally invasive artificial joint replacement and reducing surgical trauma.

[0023] The present invention will now be described in detail with reference to the accompanying drawings. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the first type of minimally invasive implantable artificial femoral head joint prosthesis of this utility model when each of the umbrella-shaped blades is in the closed state;

[0025] Figure 2 is a schematic diagram of the second type of minimally invasive implantable femoral head joint prosthesis of the present invention when each of the umbrella-shaped blades is in the closed state.

[0026] Figure 2b This is a schematic diagram of the structure of the second type of minimally invasive implantable artificial part of the femoral head joint prosthesis when the first umbrella leaf is in a semi-open state;

[0027] Figure 3a , Figure 3b , Figure 3c These are front views of the third type of minimally invasive implantable femoral head joint prosthesis of this utility model in closed, partially open, and fully open states, respectively.

[0028] Figure 3d , Figure 3e , Figure 3fThese are top views of the femoral head joint prosthesis on the surface of the third type of minimally invasive implantable artificial part of this utility model when it is in the closed, partially open, and fully open states, respectively.

[0029] Figure 3g , Figure 3h , Figure 3i This is a partial schematic diagram showing the removal of a portion of the umbrella leaf when the femoral head joint prosthesis of the third type of minimally invasive implantable artificial part of this utility model is in the closed, partially open, and fully open states, respectively.

[0030] Figure 3j , Figure 3k , Figure 3l This is a schematic diagram showing only the first and second umbilical bones and the first and second keel bones of the third type of minimally invasive implantable artificial part of the femoral head joint prosthesis of this utility model when it is in the closed, partially open and fully open states respectively;

[0031] Figure 3m , Figure 3n This is a partially enlarged schematic diagram of the first and second supporting prostheses (not shown) when the third type of minimally invasive implantable artificial part of the femoral head joint prosthesis is in a partially opened and fully opened state, respectively.

[0032] Figure 4 This is a schematic diagram of the structure of the minimally invasive implantable femoral head joint prosthesis of this utility model when all the blades are in the fully opened state (using the scheme of the top of the first sleeve abutting against the bottom of the second sleeve).

[0033] Figure 5 This is a schematic diagram of the structure of the minimally invasive implantable femoral head joint prosthesis of this utility model when all the blades are in the fully opened state (using the scheme of the first sleeve being fitted outside the second sleeve).

[0034] Figure 6 This is a perspective view of the second type of minimally invasive implantable artificial part of the femoral head joint prosthesis of this utility model before the second umbrella leaf is aligned with the first umbrella leaf;

[0035] Figure 7a This is a schematic diagram of a structure of the first support prosthesis of this utility model (the first umbrella leaf is not shown).

[0036] Figure 7b This is a schematic diagram of the second structure of the first support prosthesis of this utility model (showing the first umbrella leaf);

[0037] Figure 8 This is a diagram showing the relative relationship between the second umbrella leaf and the first connecting seat;

[0038] Figure 9 This is a top view of the first sleeve being fitted over the second sleeve;

[0039] Figure 10 This is a partial sectional view of the first sleeve being fitted over the second sleeve;

[0040] Figure 11a This is a structural diagram of one type of first connecting seat;

[0041] Figure 11b This is a schematic diagram of another structure of the first connecting seat;

[0042] Figure 11c Is with Figure 11a Schematic diagram of the second connecting seat used;

[0043] Figure 11d This is a structural diagram of the third type of the first connecting seat;

[0044] Figure 11e Is with Figure 11d Schematic diagram of the second connecting seat used;

[0045] Figure 12 The first and second support prostheses are top views of four first umbrella leaves and two umbrella leaves respectively;

[0046] Figure 13 The first and second support prostheses are top views of six first umbrella blades and six second umbrella blades, respectively.

[0047] Figure 14 This is a diagram showing the location of femoral head necrosis.

[0048] Figure 15 This is a diagram illustrating the process of cleaning the necrotic area of ​​the femoral head through a channel;

[0049] Figure 16 This is a schematic diagram of a minimally invasive implanted femoral head joint prosthesis placed through a channel.

[0050] Figure 17 This is a schematic diagram of the femoral head joint prosthesis placed through the channel after the minimally invasive implanted artificial part opens up.

[0051] Figure 18 This is a schematic diagram showing the relative positions of the first and second umbrella blades of this utility model. Detailed Implementation

[0052] like Figures 1-6The figures show different structural schematic diagrams of the minimally invasive implantable artificial surface femoral head joint prosthesis for minimally invasive interventional surgery provided by this utility model. As shown in the figures, the minimally invasive implantable artificial surface femoral head joint prosthesis of this utility model includes: an umbrella handle 1 for insertion into the femoral head surgical channel; a cylinder 2 fitted onto and movably connected to the umbrella handle; a first support prosthesis fitted onto the umbrella handle and located above the cylinder, having multiple fan-shaped first umbrella blades 7 that can open or close relative to the umbrella handle; and a second support prosthesis fitted onto the umbrella handle and located above the cylinder, having multiple fan-shaped second umbrella blades 8 that are offset from the multiple first umbrella blades and can open or close relative to the umbrella handle. The cylinder, moving upwards along the umbrella handle, pushes the multiple first umbrella blades and multiple second umbrella blades to open relative to the umbrella handle, thus assembling a complete umbrella-shaped joint prosthesis.

[0053] This invention utilizes a complete umbrella-shaped joint prosthesis, formed by the opening of multiple first and second umbrella blades. This prosthesis can replace the cartilage and subchondral bone in the necrotic area of ​​the femoral head, providing excellent mechanical support and significantly alleviating patient discomfort. It can also replace superficial necrotic cartilage, preserving most of the non-necrotic femoral head. The umbrella-shaped structure of the prosthesis supports the patient's weight, concentrating stress on the handle and transmitting it directly to the femoral shaft, reducing the load on the femoral head bone. Bone grafting within the bone tunnel strengthens the subchondral bone area, slowing the progression of femoral head necrosis. This achieves a minimally invasive partial replacement of the artificial joint, greatly reducing surgical trauma, patient suffering, and facilitating early recovery.

[0054] Specifically, the umbrella handle of this invention, used for insertion into the surgical channel of the femoral head, is a slender round rod. A cylinder is provided outside the umbrella handle, and the cylinder is threadedly connected to the umbrella handle. In the design, an external thread is provided on the outer wall of the umbrella handle, and an internal thread is provided on the inner wall of the cylinder to match the external thread of the umbrella handle, so that the cylinder can be screwed up or down relative to the umbrella handle. The lower part of the umbrella handle has an external thread, while the upper part can be smooth without an external thread, and the umbrella handle can be hollow to facilitate the insertion of a guide wire.

[0055] This invention provides a first support prosthesis and a second support prosthesis above the cylindrical part of the umbrella handle. When the first and second support prostheses are in a gradually opening state, viewed from the top of the umbrella handle looking downwards, the first and second support prostheses can be progressively joined to form a complete umbrella-shaped joint prosthesis (see [reference]). Figures 3d-3f , Figure 4 , Figure 5 , Figure 12 , Figure 13 ).

[0056] The first support prosthesis can be made of, for example Figure 7a , Figure 7bThe structure shown includes: a first connecting seat 12 fitted onto the top of the umbrella handle; and a plurality of first umbrella blades 7 evenly spaced along the circumference of the first connecting seat, the first umbrella blades being fan-shaped (see [link]). Figure 12 , Figure 13 The upper surface of the first umbrella leaf is arc-shaped and extends outward relative to the first connecting seat. Each first umbrella leaf has a slender first rib 71 fixedly connected to its upper and lower ends on its lower surface. The top of the first rib is hinged to the first connecting seat. A first sleeve 4, fitted onto the umbrella handle and movable relative to it, is located below the first connecting seat. One end of the sleeve is connected to the first rib on the back (lower surface) of the corresponding first umbrella leaf, and the other end is connected to multiple first umbrella ribs 6 at corresponding positions on the first sleeve. These multiple first umbrella ribs are evenly spaced along the circumference of the first sleeve. Furthermore, the first sleeve in the first support prosthesis can also be made of, for example... Figure 7b The ring shown is replaced by a collar.

[0057] In order for the first connector to be fitted onto the umbrella handle, the first connector can be adopted as follows: Figure 11a The structure shown is such that the first connecting seat is cylindrical, with a central through hole 121 having a diameter larger than the outer diameter of the umbrella handle. To mount the first umbrella blade on the first connecting seat, multiple protruding first ear plates 122 can be provided on the outer edge of the first connecting seat, and ear plate holes are formed on the first ear plates for hinged connection with one end of the first rib on the back of the first umbrella blade. The ear plates can be double ear plates (e.g.,...). Figure 11a As shown), the double ear plates form a U-shaped or V-shaped clamping groove. Correspondingly, one end of the first keel on the back of the first umbrella leaf is clamped between the double ear plates and hinged by a pin. Alternatively, the ear plate can be a single ear plate (not shown in the figure). Correspondingly, one end of the first keel on the back of the first umbrella leaf is provided with a U-shaped or V-shaped clamping arm for clamping the single ear plate and hinged to it by a pin.

[0058] Of course, multiple openings recessed radially inward from the outer wall of the first connecting seat can also be provided (see...). Figure 11b Each first umbrella leaf has one end that can be inserted into a corresponding opening slot and rotatably connected to the opposite side walls of the opening slot. The opening slot can be a V-shaped opening slot. Alternatively, the first connecting seat can also be hinged to the first umbrella leaf using other existing structures.

[0059] To prevent the first connecting seat from detaching from the top of the umbrella handle, a top cover 9 is also provided at the top of the umbrella handle, the outer diameter of which is larger than the outer diameter of the first connecting seat.

[0060] To allow the first umbrella leaf to close or open relative to the umbrella handle, the two ends of the first umbrella rib are hinged to the first sleeve and the first rib on the back of the first umbrella leaf, respectively. In the design, multiple first umbrella ribs can be directly hinged to the top edge of the first sleeve, or a circular stop (not shown in the figure) with an outer diameter larger than the outer diameter of the first sleeve can be provided at the top of the first sleeve, with multiple first umbrella ribs hinged to the circular stop. When a circular stop is provided at the top of the first sleeve, the hinged structure between the first umbrella ribs and the circular stop can refer to the existing connection structure between umbrella ribs and the umbrella handle, and will not be detailed here.

[0061] To allow the first sleeve to move relative to the umbrella handle, the inner diameter of the first sleeve is larger than the outer diameter of the umbrella handle. When the first sleeve is pushed upward (upward means towards the top cover), the multiple first umbrella ribs hinged to it push the first keel on the back of the corresponding first umbrella leaf, causing the first umbrella leaf supported by each first keel to open relative to the umbrella handle.

[0062] The structure of the second support prosthesis is basically the same as that of the first support prosthesis, including: a second connecting seat 13 fitted onto the umbrella handle, located below the first connecting seat and above the first sleeve (e.g., Figure 6 , Figures 3a-3n As shown, "above" and "below" refer to their positions relative to the top cover of the umbrella handle; the part closer to the top cover is called "above," and the part farther from the top cover is called "below." Multiple second umbrella blades 8 are evenly spaced along the circumference of the second connecting seat, and these second umbrella blades are also fan-shaped (see...). Figure 12 , Figure 13 The upper surface is arc-shaped and extends outward relative to the second connecting seat. Each second umbrella leaf has a slender strip-shaped second keel 81 fixedly connected to its upper and lower ends on its lower surface (see Figure 7b The second keel is hinged to the second connecting seat at its top, and multiple second umbrella blades are staggered vertically from multiple first umbrella blades; a second sleeve 3, fitted onto the umbrella handle and movable relative to it, is located below the first sleeve (see [link]). Figures 1-3n One end is connected to the second rib on the back of the second umbrella leaf, and the other end is connected to multiple second umbrella ribs 5 at corresponding positions on the second sleeve. These multiple second umbrella ribs are evenly spaced along the circumference of the second sleeve. To allow the second connecting seat to be fitted onto the umbrella handle, the second connecting seat can be designed as follows: Figure 11c The structure shown has a cylindrical second connecting seat with a central through hole 131 having a diameter larger than the outer diameter of the umbrella handle. To mount the second umbrella blade on the second connecting seat, multiple protruding second ear plates 132 can be provided on the outer edge of the second connecting seat, and ear plate holes are formed on the ear plates for hinged connection with one end of the second rib on the back of the second umbrella blade. The ear plates can be double ear plates (e.g.,...). Figure 11cAs shown), the double ear plates form U-shaped or V-shaped clamping grooves. Correspondingly, one end of the second keel on the back of the second umbrella leaf is clamped between the double ear plates and hinged to them by a pin. Alternatively, the ear plate can be a single ear plate (not shown in the figure). Correspondingly, one end of the second keel on the back of the second umbrella leaf is provided with a U-shaped or V-shaped clamping arm for clamping the single ear plate and hinged to it by a pin. Of course, multiple opening grooves that are radially recessed inward from their outer wall can also be opened on the second connecting seat (see reference). Figure 11b The second rib on the back of each second umbrella leaf can be inserted into the corresponding opening slot and rotatably connected to the opposite side walls of the opening slot. The opening slot can be a V-shaped opening slot. In addition, the second connecting seat can also be hinged to the second umbrella leaf using other existing structures.

[0063] During assembly, the second connecting seat is located below the first connecting seat. To ensure that the multiple second umbrella blades mounted on the second and first connecting seats, and the upper surfaces of each first umbrella blade, lie on the same spherical surface after opening, forming a smooth support surface, the second connecting seat needs to be inserted into the first connecting seat. In the design, a countersunk hole can be formed at the bottom of the first connecting seat, creating a step with the first through hole. The diameter of the countersunk hole is larger than the outer diameter of the first through hole and the second connecting seat, allowing the second connecting seat to be inserted into the stepped hole.

[0064] In order to allow the second umbrella blade installed on the second connector to be spliced ​​with the first umbrella blade installed on the first connector after the second connector is inserted into the first connector, multiple notches 123 are made at equal angle intervals on the side wall of the first connector (e.g., Figure 11a The diagram shows three notches, allowing the second umbrella blade to extend outward from the notch in the first connecting seat. To ensure that the upper surface of the extended second umbrella blade is flush with the upper surface of the first umbrella blade, the second umbrella blade can be designed as follows: Figure 8 The structure shown is such that the part connected to the second connecting seat is provided with a recessed platform that is recessed downward from the upper surface, and the height of the recessed platform should be such that the upper surface of the second umbrella blade can be located on the same surface as the upper surface of the second connecting seat.

[0065] Alternatively, the second connector 13 can also adopt the following: Figure 11e The structure shown includes: an annular circular plate with a second through hole 131 at its center; a plurality of arc-shaped plates 134 fixedly connected to the upper surface edge of the annular circular plate and extending radially, each arc-shaped plate having an outer surface flush with and concentric with the outer surface of the annular circular plate, and forming a butt joint groove between adjacent arc-shaped plates; and a pair of second ear plates 132 disposed on the outer wall of each arc-shaped plate, the second ear plates having ear plate holes for hinged to one end of the corresponding second keel. Correspondingly, the first connecting seat that mates with the second connecting seat of this structure can be adopted as follows: Figure 11dThe structure shown is the same as the second connecting seat, except that the two are installed opposite each other on the umbrella handle during use. That is, the first connecting seat is installed facing forward (with the annular plate on top) and the second connecting seat is installed backward (with the annular plate on the bottom). The arc-shaped plate of the first connecting seat is inserted into the corresponding mating groove of the second connecting seat, and the mating groove of the first connecting seat is inserted into the corresponding arc-shaped plate on the second connecting seat.

[0066] To allow the second umbrella blade to close or open relative to the umbrella handle, the two ends of the second umbrella rib are hinged to the second sleeve and the second rib on the back of the second umbrella blade, respectively. In the design, multiple second umbrella ribs can be directly hinged to the top edge of the second sleeve, or a circular stop (not shown in the figure) with an outer diameter larger than the outer diameter of the first sleeve can be provided at the top of the first sleeve, and multiple second umbrella ribs can be hinged to the circular stop. When a circular stop is provided at the top of the first sleeve, the hinged structure between the first umbrella rib and the circular stop can refer to the existing connection structure between umbrella ribs and the umbrella handle, and will not be described in detail here.

[0067] To allow the second sleeve to move relative to the umbrella handle, the inner diameter of the second sleeve is larger than the outer diameter of the umbrella handle. When the second sleeve is pushed upward, the multiple second umbrella ribs hinged to it push the second keel on the back of the corresponding second umbrella leaf, causing the second umbrella leaf supported by each second keel to open relative to the umbrella handle.

[0068] Since the first sleeve is located above the second sleeve, in order for the first sleeve to move upward along the umbrella handle under the action of the second sleeve, the design can make the outer diameter of the first sleeve larger than the through hole of the second sleeve but smaller than the outer diameter of the second sleeve. This way, when the second sleeve moves upward, its top end can abut against the lower end of the first sleeve (e.g., ...). Figure 4 As shown), this causes the first sleeve to move upwards. Alternatively, a countersunk hole can be made at the top of the second sleeve (as shown). Figure 10 As shown), the first sleeve can be inserted into the countersunk hole. When the second sleeve moves upward, the first sleeve can be fitted into the countersunk hole of the second sleeve, and its lower end is abutted by the second sleeve (as shown). Figure 5 As shown, it moves upward with the second sleeve. Furthermore, a key 41 can be provided on the outer wall of the first sleeve, and a keyway (such as...) can be provided on the inner wall of the second sleeve to mate with the key. Figure 9 (as shown), thereby preventing the first sleeve from wobbling relative to the second sleeve.

[0069] The umbrella features multiple identical first umbrella blades and multiple identical second umbrella blades. The first and second umbrella blades can be fan-shaped with similar or slightly different angular radii, radii, and arc lengths. The length of the first umbrella rib hinged to the first umbrella blade is greater than or equal to the length of the second umbrella rib hinged to the second umbrella blade. During manufacturing, each umbrella blade is made of metal, such as a cobalt-chromium-molybdenum alloy or other metals with sufficient strength and ductility, and the upper surface of each umbrella blade is a highly polished, smooth, arc-shaped surface. Furthermore, different sizes of umbrella-shaped prostheses can be used during manufacturing to meet the repair needs of lesions of different sizes.

[0070] The dimensional relationships between the ribs on the back of each umbrella leaf, each sleeve, and the top cover can be as follows: Figure 18 As shown in the figure, the length of the rib on the back of the first umbrella leaf is 'a' (the length of the rib on the back of the first umbrella leaf is the same as the length of the rib on the back of the second umbrella leaf), the distance between the first sleeve and the lower surface of the top cover is 'c', the length of the first umbrella rib is 'b', the distance between the second sleeve and the first sleeve is 'h', and when opened, the angle between the rib on the back of the first umbrella leaf and the umbrella handle is 'A', and the angle between the first umbrella rib and the umbrella handle is 'B'. In the design, the lengths of the rib on the back of the first umbrella leaf and the first umbrella rib can be equal. When opened, the angles A between the rib on the back of the first umbrella leaf and the umbrella handle and B between the first umbrella rib and the umbrella handle can be equal. Preferably, A and B are both 45 degrees, and the distance c between the first sleeve and the lower surface of the top cover is 2. 1 / 2 a, The distance between the second sleeve and the top cover is (2-2 1 / 2 Correspondingly, the angle between the second umbrella blade and the umbrella handle is also A, and the length of the first umbrella rib and the angle between it and the umbrella handle can be determined based on this angle A and the length of the keel on the back of the first umbrella blade (which is equal to the length of the second umbrella blade). Of course, during the design process, support prostheses with different radii of curvature and the above parameter values ​​can be determined according to actual needs.

[0071] After assembly, viewed from above the canopy, there is a second leaf between every two first leaflets, and a first leaflet between every two second leaflets (see...). Figures 3d-3f , Figure 12 , Figure 13 Multiple first and second umbrella blades, when fully opened, can be pieced together to form a complete umbrella shape (e.g. Figure 3c , Figure 4 , Figure 5 (As shown). In application, the number of first and second umbrella blades can be selected according to actual needs; for example, three first umbrella blades and three second umbrella blades can be used respectively (see...). Figures 3a-3n ), or they can be four first fins and four second fins respectively (see Figure 4 ), or they can be six first umbels and six second umbels respectively (see Figure 5 The umbrella can also have eight or more first and second blades. When closed, each blade fits snugly against the handle, and when open, they interlock to form a spherical surface.

[0072] This invention arranges multiple first umbrella leaves and multiple second umbrella leaves in two layers, that is, after the first umbrella leaves are opened, the gap between the two first umbrella leaves is filled by the second umbrella leaves. This can avoid the disadvantage that metal umbrella leaves cannot be folded, and make it easy for each umbrella leaf to be stacked and wrapped around the umbrella handle when closed, reducing the overall volume. This is convenient for storage and also facilitates the delivery of the femoral head joint prosthesis to the preset position through the channel during minimally invasive surgery.

[0073] In use, rotate the cylinder upward along the handle axis (upward means towards the top cover) so that the top of the cylinder abuts against the second sleeve. As the cylinder continues to rotate, the second sleeve moves upward and pushes the corresponding second umbrella leaf open through multiple second umbrella ribs. When the second sleeve moves upward to a position that can push the first sleeve to move upward with it, as the cylinder continues to rotate, the first sleeve and the second sleeve move upward simultaneously, and the second umbrella leaf continues to open. The first umbrella leaf connected to the first sleeve through the first umbrella rib will also open until both the second umbrella leaf and the first umbrella leaf are fully opened to the required angle. Multiple second umbrella leaves and multiple first umbrella leaves are staggered and spliced ​​to form an umbrella-shaped joint prosthesis with the upper surface located on the same spherical surface.

[0074] To prevent the cylinder from sliding backward along the handle axis after the second and first umbrella blades are fully opened, a tail cap 10 can be screwed onto the end of the handle (i.e., the end furthest from the top cover). This tail cap can be conical, screwed in or tapped to ensure the tip of the cap engages with the end of the handle via threads or a taper. The diameter of the tail cap's end is slightly larger than the diameter of the rib channel, creating a bottle stopper effect to secure it within the rib channel.

[0075] The cylinder can be moved forward or backward along the umbrella handle axis by manual rotation or by using other means such as an electric drive assembly. Correspondingly, a locking groove (not shown in the figure) can be provided on the outer wall of the cylinder, and the power output component of the electric drive assembly can be locked in the locking groove. Thus, when the electric drive assembly is working, the power output component drives the cylinder forward or backward along the umbrella handle. Furthermore, if an auxiliary tool is needed when manually rotating the cylinder, the tool should also engage with the locking groove. The structure of the locking groove on the cylinder and the other parts engaging with it can refer to existing technology, and the electric drive assembly that drives the cylinder forward or backward along the umbrella handle is also existing technology, and will not be described in detail here.

[0076] Furthermore, to increase the friction with bone in the early stages after the femoral head joint prosthesis of this invention is implanted into the patient, and to allow it to integrate with the bone and form a long-term fixation effect, a coating can be applied to the underside of each umbrella blade, each keel, each umbrella handle, each sleeve, and the surface of the cylinder. The coating can be a hydroxyapatite, titanium, or tantalum metal particle coating. This coating can heal with the implanted new bone, retaining more bone and strengthening the mechanical support beneath the umbrella-shaped prosthesis.

[0077] When a patient has avascular necrosis of the femoral head (e.g.) Figure 14 The uppermost part), through an opening in the lateral femoral cortex, creates a bone tunnel to the necrotic area of ​​the weight-bearing zone of the femoral head (such as...). Figure 15 As shown), after treating the necrotic bone in the necrotic area, a joint prosthesis that meets the dimensional requirements is fabricated based on the corresponding dimensional data obtained from preoperative examination calculations or intraoperative measurements using a probe. During the surgery, under fluoroscopic conditions, a positioning guide pin is inserted through the bone channel, with its tip reaching the necrotic area of ​​the femoral head and its tail end protruding from the entrance of the bone channel. This pin is then inserted into the hollow of the umbrella handle of the fabricated joint prosthesis. The joint prosthesis is inserted into the necrotic area along the guide pin. Then, by screwing in a cylinder outside the umbrella handle, the cylinder sequentially presses against the second sleeve where the end of the second umbrella rib is located and the first sleeve where the end of the first umbrella rib is located, causing the first and second umbrella blades to move upward and unfold (as shown). Figure 16 As shown), until the femoral head prosthesis is fully opened to form an umbrella shape, the direction of the prosthesis is adjusted to form a smooth, umbrella-shaped, minimally invasive implantable artificial part of the femoral head joint prosthesis in the necrotic area (as shown). Figure 17 (As shown). The outer surface of the umbrella-shaped prosthesis is a highly polished metal surface. Through different size designs, it fits the surface cartilage of the patient's femoral head to form a spherical surface, thereby achieving the purpose of repairing the femoral head surface and restoring the spherical structure of the femoral head.

[0078] This invention's prosthesis, once opened, achieves anastomosis and frictional rotation with the acetabular cartilage through its smooth outer surface. Autologous or allogeneic bone grafts are used to fill the voids in the necrotic area via the space beneath the umbrella-shaped support structure and ribs. The umbrella-shaped support secures the prosthesis within the entire bone channel, allowing surface forces to be transmitted and dispersed throughout the bone channel and then conducted to the femoral shaft, forming a physiologically sound mechanical transmission mechanism. The opened prosthesis can fully bear weight, reducing stress on the host bone beneath the umbrella, thus slowing the progression of osteonecrosis. It also allows for the grafting of various biomaterials into the necrotic area or the promotion of bone growth.

[0079] This invention relates to a minimally invasive implantable artificial partial-surface femoral head joint prosthesis, specifically for partial femoral head replacement surgery. Applied to patients with femoral neck fractures, it allows for the direct replacement of cartilage in the necrotic area of ​​the femoral head with a smooth metal surface. The prosthesis's own support structure provides support to the metal surface, distributing the patient's weight-bearing force to the femoral shaft. Simultaneously, new bone material can be implanted within the structure, facilitating healing with the patient's bone when the bone material itself does not bear weight. This joint prosthesis is foldable and can be implanted via an interventional method, involving drilling into the femoral head for insertion. Therefore, it is also a minimally invasive surgical treatment for artificial partial-surface femoral head joint prostheses. This prosthesis can repair the necrotic area of ​​the femoral head by directly replacing the cartilage in the necrotic area with a highly polished artificial metal articular surface. It has a good mechanical support structure, which can relieve patients' symptoms and improve their function. At the same time, the fact that the prosthesis needs to be drilled for implantation can also increase blood circulation in the femoral head, slow down the further development of necrosis, and significantly delay or even avoid the need for total hip replacement. In addition, the use of interventional minimally invasive surgical methods reduces surgical trauma and the occurrence of postoperative complications.

[0080] Although the present invention has been described in detail above, it is not limited thereto. Those skilled in the art can make modifications based on the principles of the present invention. Therefore, all modifications made in accordance with the principles of the present invention should be understood as falling within the protection scope of the present invention.

Claims

1. A minimally invasive implantable artificial femoral head joint prosthesis, characterized in that, include: Umbrella handle; A cylinder fitted onto and movably connected to the umbrella handle; The first support prosthesis, mounted on the umbrella handle and located above the cylinder, has multiple fan-shaped first umbrella leaves that can be closed or opened relative to the umbrella handle; The second support prosthesis, mounted on the umbrella handle and located above the cylinder, has multiple fan-shaped second umbrella leaves that are offset from the multiple first umbrella leaves and can be closed or opened relative to the umbrella handle. Among them, multiple first umbrella blades and multiple second umbrella blades are metal umbrella blades, the upper surface of each umbrella blade is a highly polished and smooth arc surface, and the lower surface of each umbrella blade, each umbrella handle, and the cylindrical surface are coated with a coating that can heal with the implanted new bone. Multiple first umbrella blades and multiple second umbrella blades can be opened relative to the umbrella handle and interlocked to form a complete umbrella-shaped joint prosthesis with its upper surface located on the same spherical surface under the push of the cylinder.

2. The minimally invasive implantable artificial femoral head joint prosthesis according to claim 1, characterized in that, The first support prosthesis also includes: A first connecting seat is installed at the top of the umbrella handle, and the plurality of first umbrella blades are distributed circumferentially at intervals along the first connecting seat; A first sleeve fitted onto the umbrella handle and movable relative to it; One end is connected to the back of the corresponding first umbrella leaf, and the other end is connected to multiple first umbrella ribs at the corresponding positions of the first sleeve.

3. The minimally invasive implantable artificial femoral head joint prosthesis according to claim 2, characterized in that, The first umbrella rib is hinged to the first sleeve and the first umbrella blade, respectively.

4. The minimally invasive implantable artificial femoral head joint prosthesis according to claim 1, characterized in that, The second support prosthesis also includes: A second connecting seat is installed on the umbrella handle, and the plurality of second umbrella blades are distributed circumferentially at intervals along the second connecting seat; A second sleeve fitted onto the umbrella handle and movable relative to it; One end is connected to the back of the corresponding second umbrella leaf, and the other end is connected to multiple second umbrella ribs at the corresponding positions of the second sleeve.

5. The minimally invasive implantable artificial femoral head joint prosthesis according to claim 4, characterized in that, The second umbrella rib is hinged to the second sleeve and the second umbrella blade respectively.

6. The minimally invasive implantable artificial femoral head joint prosthesis according to claim 4, characterized in that, The second sleeve is located below the first sleeve.

7. The minimally invasive implantable artificial femoral head joint prosthesis according to claim 4, characterized in that, The length of the second umbrella rib is less than or equal to the length of the first umbrella rib.

8. The minimally invasive implantable artificial femoral head joint prosthesis according to claim 1, characterized in that, The cylinder is threadedly connected to the umbrella handle.

9. The minimally invasive implantable artificial femoral head joint prosthesis according to any one of claims 1-8, characterized in that, It also includes a tail cap that is threaded to the lower end of the umbrella handle.

10. The minimally invasive implantable artificial femoral head joint prosthesis according to claim 1, characterized in that, It also includes a top cover that is fixedly connected to the top of the umbrella handle.

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