A femoral stem prosthesis

Abstract

The present invention relates to the field of orthopedic medical devices, and in particular to a femoral stem prosthesis, comprising an upper end that is connected to each other and a lower end that fixes the position of the femoral stem prosthesis, a protrusion is provided on one side of the upper end, and a baffle that contacts the intertrochanteric fracture is provided on the other side, thereby achieving the effect of being able to repair the intertrochanteric fracture, reducing the number and probability of complications, and improving the success rate of the operation.

Description

Technical Field

[0001] The invention relates to the field of orthopedic medical instruments, and in particular to a femoral stem prosthesis. Background Art

[0002] The outer side of the upper femur is the greater trochanter, the lower side is the lesser trochanter, and the junction of the femoral shaft and the femoral neck is the intertrochanteric area, which is the area subject to the greatest shear stress. The greater trochanter, lesser trochanter and intertrochanteric area are all cancellous bones. Due to the particularity of the force line distribution, a dense longitudinal bone plate is formed at the inner and rear side of the connection between the femoral neck and the femoral shaft, called the femoral calcar. The femoral calcar extends vertically upward along the anterior and lateral side of the lesser trochanter, the upper pole is fused with the posterior cortical bone of the femoral neck, the lower pole is fused with the posterior medial cortical bone of the femoral shaft below the lesser trochanter, the front edge is connected to the anterior medial cortical bone of the upper femur, and the rear edge is connected to the outer and posterior side of the upper end of the femur. The existence of the femoral calcar determines the stability of intertrochanteric fractures.

[0003] The existing artificial hip joint prosthesis imitates the structure of the human hip joint. The prosthesis handle is inserted into the femoral medullary cavity, and the head and the acetabulum or the prosthesis metal cup are rotated to achieve flexion and extension and movement of the femur.

[0004] The above-mentioned existing technical solutions have the following defects: the artificial hip joint handle structure has certain limitations. For example, when the femoral trochanter is fractured, bone plates are often used for treatment and bone screws are used for fixation. When artificial hip replacement surgery is required at the same time, the bone screws of the bone plate have the disadvantage of being unable to be fixed. With the improvement of people's living standards, patients' requirements for surgery are gradually increasing. In order to reduce the probability of complications and improve the success rate of surgery and postoperative effects, a design that can solve the problem of intertrochanteric fracture repair is urgently needed in the existing technology. Summary of the invention

[0005] The purpose of the present invention is to provide a femoral stem prosthesis, which can repair intertrochanteric fractures, reduce the frequency and probability of complications, and improve the success rate of surgery.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] A femoral stem prosthesis comprises an upper end connected to each other and a lower end for fixing the position of the femoral stem prosthesis, a bulge is arranged on one side of the upper end, and a baffle contacting with an intertrochanteric fracture is arranged on the other side.

[0008] By adopting the above scheme, when people have an intertrochanteric fracture, they can insert the lower end of the femoral stem prosthesis into the femur, the protrusion on the upper end of the femoral stem prosthesis can be connected to the hip joint, and the baffle at the upper end can contact the trochanteric bone. Afterwards, people can wrap a steel wire between the femoral stem prosthesis and the femur, which can make the femoral stem prosthesis more stably fixed, thus completing the repair of the intertrochanteric fracture; because there is no need to use a bone plate or bone screws at this time, it is convenient for people to replace the hip joint later, thereby reducing the number and probability of complications and increasing the success rate of the operation.

[0009] The present invention is further configured such that the cross-sectional shape of the lower end is conical and the tip thereof faces away from the upper end.

[0010] By adopting the above solution, the lower end is set to be conical, which makes it easy to insert the lower end into the femur.

[0011] The present invention is further configured such that a plurality of ridges are provided on the outer surface of the lower end along the axial direction of the lower end.

[0012] By adopting the above solution, the convex ridges at the lower end can reduce the possibility of the lower end of the femoral stem prosthesis rotating inside the femur.

[0013] The present invention is further configured such that a TI coating and a HA coating are provided between two adjacent convex ridges.

[0014] By adopting the above scheme, the TI coating increases the friction and porosity of the femoral stem prosthesis, prolongs the initial and long-term stability, and the HA coating can induce bone ingrowth, allowing the femoral stem prosthesis to grow rapidly and enhance the anti-sinking ability of the femoral stem prosthesis.

[0015] The present invention is further configured such that the surface of the lower end is provided with trabeculae, and the trabeculae are located on a side of the convex ridge close to the upper end.

[0016] By adopting the above scheme, the trabeculae on the lower end surface are conducive to bone growth.

[0017] The present invention is further configured such that the baffle is recessed inwardly away from the convex side surface, and bone trabeculae are arranged on the inner surface of the baffle.

[0018] By adopting the above scheme, the trabeculae on the inner surface of the baffle are conducive to bone growth.

[0019] The present invention is further configured such that a bolt hole is provided on one side of the upper end away from the protrusion.

[0020] By adopting the above scheme, if the patient's intertrochanteric fracture is a severe fracture, people can install a protective plate that matches the femoral stem prosthesis on the side of the femur away from the protrusion, and open mounting holes on the protective plate and the femur, and use bolts to connect the mounting plate, femur and femoral stem prosthesis together.

[0021] The present invention is further configured such that the upper end and the lower end are connected via a cone-matching structure or are integrally formed.

[0022] The present invention is further configured such that the trabeculae are formed by laser melting technology.

[0023] By adopting the above scheme, laser cladding technology can be used for cladding on substrates of different materials, and the cladding powder materials can also be varied, which can be applied to different parts of the human body and has strong applicability.

[0024] In summary, the present invention has the following technical effects:

[0025] 1. By setting up the femoral stem prosthesis, people can use the femoral stem prosthesis to repair the intertrochanteric fracture when they have it, thereby reducing the frequency and probability of complications and increasing the success rate of the operation;

[0026] 2. By providing the convex ridge, after the lower end of the femoral rod is inserted into the femur, the convex ridge can reduce the possibility of the lower end of the femoral stem rotating inside the femur;

[0027] 3. By setting up trabeculae, trabeculae can promote bone growth at the intertrochanteric fracture site. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is an overall structural diagram of a femoral stem prosthesis in Embodiment 1 of the present invention;

[0029] Figure 2 It is the overall structural diagram of the holding frame in the present invention;

[0030] Figure 3 yes Figure 1 Cross-section view from medium AA perspective.

[0031] In the figure, 1, femoral stem prosthesis; 11, upper end; 12, lower end; 13, protrusion; 14, baffle; 141, Kirschner wire hole; 15, convex ridge; 16, first threaded hole; 2, holding frame; 21, holding rod; 22, sleeve; 23, limit block; 3, trabeculae. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0033] The area between the greater trochanter and the lesser trochanter is mainly composed of cancellous bone, which is rich in blood supply and is supplied by the branches of the lateral and medial femoral circumflex arteries. The gluteus medius and gluteus minimus are attached to the greater trochanter, and are pulled upward and outward after a greater trochanter fracture; the iliopsoas is attached to the lesser trochanter, and is pulled upward and inward after a lesser trochanter fracture; the adductor muscles cause the distal fracture to shift inward and upward, so if intertrochanteric injuries are not repaired in time, the affected limb will be shortened and externally rotated, and the branches of the lateral and medial femoral circumflex arteries will be insufficiently supplied, causing adverse effects.

[0034] The trabeculae between the trochanters and the trabeculae at the femoral head form a triangular mechanical structure like a cantilever. The primary and secondary pressure trabeculae are integrated with the medial cortex and the medial femoral calcar to play a supporting role, thereby resisting the strong varus stress of the hip. If the intertrochanteric space is not repaired, it will not play a supporting role, and therefore cannot resist the strong varus stress of the hip.

[0035] The femoral calcar is a dense bone plate located in the inner and posterior part of the connection between the femoral neck and the femoral body deep in the lesser trochanter. It is an extension of the posteromedial cortex of the femoral body into the cancellous tissue. Some people describe it as the "real femoral neck". It radiates outward to the gluteal tuberosity and is a continuous spiral lamellar structure. It is the focus of eccentric loading of the upper end of the femur, which is equivalent to the foundation of the crane beam. It bears huge compressive gravity when standing upright. Its lower pole is fused with the posteromedial cortical bone of the femoral body below the lesser trochanter, and it goes vertically upward along the anterior and lateral side of the lesser trochanter, and the upper pole is fused with the posterior cortex of the femoral neck. If the trochanter is not repaired, the femoral calcar cannot be reconstructed, so it cannot bear the eccentric loading of the upper end of the femur, and cannot withstand the huge compressive gravity when standing upright. It will also cause pain to the patient and make it impossible to walk and stand normally. In addition, some patients suffer from intertrochanteric fractures, which cause discomfort and lead to psychological diseases.

[0036] The femoral calcar is an important part of the internal structure of the proximal femur, located near the starting point of the lesser trochanter. It is closely related to the load-bearing function, stress conduction, stress distribution and fracture line distribution of the proximal femur, and plays a major role in the internal fixation of proximal femoral fractures and artificial joint prosthesis replacement. From a biomechanical point of view, the femoral calcar and the pressure trabeculae of the inner and lower cortical bone of the femoral neck 3 jointly bear the compressive stress and bending moment formed by the eccentric load applied to the femoral head. If the intertrochanteric fracture is not repaired, the compressive stress formed by the eccentric load on the femoral head cannot be borne.

[0037] Reference Figure 1The present invention provides a femoral stem prosthesis, comprising an upper end 11, a lower end 12, a protrusion 13 and a baffle 14, wherein the lower end 12 of the femoral stem prosthesis 1 is 120 mm long and has a diameter of 14-24 mm, the upper end 11 of the femoral stem prosthesis 1 is 80-110 mm long, with a specification of 10 mm per time, and a diameter of 14-24 mm, the upper end 11 is integrally fixed to the lower end 12 or detachably connected to the lower end 12 via a connecting block provided on the upper end 11, and the lower end The interface shape of 12 is conical and the tip is away from the upper end 11, the protrusion 13 is arranged on one side of the upper end 11, and the baffle 14 is arranged on the side of the upper end 11 away from the protrusion 13. The baffle 14 has a certain physiological curvature, so that the baffle 14 can be in closer contact with the bone at the intertrochanteric fracture. The width of the baffle 14 is the same as the thickness of the upper end 11 of the femoral stem prosthesis 1. The height of the baffle 14 is 5-15mm. In the present invention, the height of the baffle 14 is 10mm.

[0038] Reference Figure 2 When using the femoral stem prosthesis 1 to repair the intertrochanteric fracture, first install the holding frame 2 on the femoral stem prosthesis 1, and then insert the lower end 12 of the femoral stem prosthesis 1 into the femur through the holding frame 2, the baffle 14 on the femoral stem prosthesis 1 will contact the bone at the intertrochanteric fracture, and the protrusion 13 will be connected to the artificial hip joint, thereby achieving the effect of repairing the intertrochanteric fracture.

[0039] Reference Figure 2 The holding frame 2 includes a holding rod 21 and a sleeve 22. The holding rod 21 is arranged on the side of the upper end 11 of the femoral stem prosthesis 1 away from the lower end 12. A holding hole is opened on the upper end 11 of the femoral stem prosthesis 1. The end of the holding rod 21 close to the femoral stem prosthesis 1 extends into the holding hole and is threadedly connected to the upper end 11. The sleeve 22 is sleeved on the holding rod 21 and is threadedly connected to the holding rod 21. A limiting block 23 is arranged on the end surface of the sleeve 22 close to the upper end 11 of the femoral stem prosthesis 1. There are two limiting blocks 23 in total, and the two limiting blocks 23 are respectively located on both sides of the holding rod 21. A limiting groove for the limiting block 23 to enter is opened inside the holding hole.

[0040] When the holding frame 2 is needed, first insert one end of the sleeve 22 into the upper end 11 of the femoral stem prosthesis 1. At this time, it is necessary to ensure that the two limit blocks 23 on the sleeve 22 enter the limit groove inside the holding hole; then insert the holding rod 21 into the sleeve 22, and then rotate the holding rod 21. One end of the holding rod 21 will be screwed into the holding hole, and the side of the holding rod 21 will be threadedly connected to the sleeve 22, and the holding rod 21 can drive the femoral stem to move together.

[0041] Reference Figure 1After the femoral stem prosthesis 1 is inserted into the femur, in order to facilitate people to fix the femoral stem prosthesis 1 on the patient's femur, a Kirschner wire hole 141 is opened on the baffle 14. The diameter of the Kirschner wire hole 141 is 1.5-3mm. In the present invention, the diameter of the Kirschner wire hole 141 is 3mm. After the femoral stem prosthesis 1 is inserted into the femur, people can insert a Kirschner wire into the Kirschner wire hole 141 to fix the position of the femoral stem prosthesis 1.

[0042] Reference Figure 1 and Figure 3 After the femoral stem prosthesis 1 is inserted into the femur, in order to reduce the possibility of the femoral stem prosthesis 1 rotating inside the femur, 4-8 ridges 15 are arranged on the femoral stem prosthesis 1 along the circumference of the lower end 12. The height of the ridge 15 is 2mm and the width is 0.6-1mm. In the present invention, there are 4 ridges 15 in total, and the width of the ridge 15 is 1mm.

[0043] The baffle 14 of the upper end 11 of the femoral stem prosthesis 1 and the area 20 mm below are the proximal end of the femoral stem, and the rest of the area is the distal end of the femoral stem. The proximal end of the femoral stem is formed by electron beam melting technology.

[0044] After the femoral stem prosthesis is inserted into the femur, TI coating and HA coating are sprayed on the distal surface of the femoral stem to increase the friction and porosity of the prosthesis, increase the initial and long-term stability, induce bone ingrowth, enable the femoral stem prosthesis to grow rapidly, and enhance the anti-sinking ability of the femoral stem prosthesis.

[0045] Reference Figure 1 In order to facilitate bone growth at the intertrochanteric fracture site, the side of the baffle away from the protrusion is recessed inward, and a layer of trabecular bone with a thickness of 2 mm is printed on the outer surface of the proximal end of the femoral stem and the surface of the baffle away from the protrusion by laser melting technology.

[0046] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A femoral stem prosthesis, characterized in that: The invention comprises an upper end (11) connected to each other and a lower end (12) for fixing the position of a femoral stem prosthesis (1); a protrusion (13) is arranged on one side of the upper end (11); a baffle (14) in contact with the intertrochanteric fracture is arranged on the other side; the baffle (14) is provided with a Kirschner wire hole (141); the aperture of the Kirschner wire hole (141) is 1.5-3 mm; the side of the baffle (14) away from the protrusion (13) is recessed inward, and a bone trabecula (3) is arranged on the inner surface of the baffle (14).

2. A femoral stem prosthesis according to claim 1, characterized in that: The cross-sectional shape of the lower end (12) is conical and the tip thereof faces away from the upper end (11).

3. A femoral stem prosthesis according to claim 2, characterized in that: A plurality of ridges (15) are arranged on the outer surface of the lower end (12) along the circumference of the lower end (12).

4. A femoral stem prosthesis according to claim 3, characterized in that: A TI coating and a HA coating are provided between two adjacent convex ridges (15).

5. A femoral stem prosthesis according to claim 4, characterized in that: The surface of the lower end (12) is provided with bone trabeculae (3), and the bone trabeculae (3) are located on the side of the convex ridge (15) close to the upper end (11).

6. A femoral stem prosthesis according to claim 1, characterized in that: A bolt hole is provided on a side of the upper end (11) away from the protrusion (13).

7. A femoral stem prosthesis according to claim 1, characterized in that: The upper end (11) and the lower end (12) are connected via a cone-matching structure or are integrally formed.

8. A femoral stem prosthesis according to claim 1 or 5, characterized in that: The trabeculae (3) are formed by laser melting technology.

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