COBRA TYPE FEMORAL STEM PROSTHESIS

Abstract

The present disclosure provides a cobra type femoral stem prosthesis, that is a femoral stem prosthesis for congenital dysplasia of the hip (CDH) which includes a femoral stem cone, a femoral neck and a stem body which are connected sequentially; the stem body includes proximal segment of femoral stem, middle segment of femoral stem and distal segment of femoral stem, wherein the femoral stem cone is a cone shape; One end of the femoral neck is connected with the proximal segment of femoral stem and there is a deflection angle therebetween and the other end of the femoral neck is connected with the large diameter end of the femoral stem cone.

Claims

1. A cobra type femoral stem prosthesis, that is a femoral stem prosthesis for congenital dysplasia of the hip (CDH), which comprises a fernoral stem cone, a femoral neck and a stem body which are connected sequentially; the stem body comprising a proximal segment of a femoral stem, a middle segment of the femoral stem and a distal segment of the femoral stem, characterized in that the femoral stem cone is a cone shape; one end of the femoral neck is connected with the proximal segment of the femoral stem and there is a deflection angle therebetween, and the other end of the femoral neck is connected with large diameter end of the femoral stem cone; a surface of the proximal segment of the femoral stem is provided with a plurality of annular microgrooves; and an outer surface of the distal segment of the femoral stem is provided with a plurality of longitudinal lateral ridges extending longitudinally.

2. The cobra type femoral stem prosthesis according to claim 1, characterized in that, an acute angle between an axis of the proximal segment of the femoral stem and an axis of the femoral neck is 035 or 145180.

3. The cobra type femoral stem prosthesis according to claim 1, characterized in that, an angle between a central line of the stem body and a central line of the femoral neck is 120140.

4. The cobra type femoral stem prosthesis according to claim 1, characterized in that, the outer surface of the distal segment of the femoral stem is provided with four to ten lateral ridges, which have a height of 0.550.65 mm.

5. The cobra type femoral stem prosthesis according to claim 1, characterized in that, cross section of the femoral neck is oval.

6. The cobra type femoral stem prosthesis according to claim 1, characterized in that, the annular microgrooves have a width of 1.01.5 mm, and have a depth of 0.40.5 mm.

7. The cobra type femoral stem prosthesis according to claim 1, characterized in that, the outer surface of the proximal segment of the femoral stem is sprayed with Ti coating which has a thickness of 50800 um.

Description

DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a schematic diagram of the cobra type femoral stem prosthesis according to the disclosure;

[0016] FIG. 2 is a coronal diagram of the cobra type femoral stem prosthesis according to the disclosure;

[0017] FIG. 3 is a diagram of a deflection angle of the artificial alpha femoral stem prosthesis according to the disclosure.

DESCRIPTION OF MAIN COMPONENT SIGN

[0018] 1femoral stem cone;

[0019] 2femoral neck:

[0020] 3stem body;

[0021] 4proximal segment of the femoral stem;

[0022] 5middle segment of the femoral stem;

[0023] 6distal segment of the femoral stem;

[0024] 7annular microgrooves;

[0025] 8longitudinal lateral ridge

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0026] In order to make the technical problems, technical solutions and advantages to be solved more clearly, the following drawings and specific examples will be described in detail.

[0027] As shown in FIG. 1 to FIG. 3, a cobra type femoral stem prosthesis of the disclosure includes a femoral stem cone 1, a femoral neck 2 and a stem body 3 which are connected sequentially; wherein the stem body includes a proximal segment of femoral stem 4, a middle segment of the femoral stem 5 and a distal segment of the femoral stem 6. The femoral stem cone 1 is a cone shape. There is a deflection angle between one end of the femoral neck 2 and the proximal segment of femoral stem 4, and the other end of the femoral neck 2 is connected with the large diameter end of the femoral stem cone 1.

[0028] The outer surface of the proximal segment of the femoral stem is provided with a plurality of annular microgrooves 7, which effectively increases the contact area of the prosthesis and the bone interface, and ensures the stability of the prosthesis after the prosthesis is implanted. In the present embodiment, sawtooth groove is optimally selected for the annular microgroove, with a groove width of 1.01.5 mm and a groove depth of 0.40.5 mm.

[0029] Wherein, the angle between the axis of the proximal segment of the femoral stem 4 and the axis of the femoral neck 2 is angle , which is anteversion angle and is 035145180, preferably 15, 35, 145 and 165.

[0030] Furthermore, the angle between the central line of the stem body 3 and the central line of the femoral neck 2 is 120140, and the optimum value is 130. The design of this angle is more in line with the structure of human physiological anatomy.

[0031] The outer surface of the distal segment of the femoral stem is provided with four to ten longitudinal lateral ridge 8, preferably eight, enhancing the initial stability of the prosthesis and antirotation performance. In this embodiment, the height of the longitudinal lateral ridge is 0.550.65 mm, that is the outside diameter of the longitudinal lateral ridge is about 1.25 mm more than the foundation diameter of the femoral stem.

[0032] Wherein, the cross section of the femoral neck 2 is oval, which increases the range of activity of the prosthesis and reduces the abrasion between the femoral neck 2 and the lining of the total acetabulum.

[0033] Wherein, Ti coating is sprayed on the surface of the proximal segment of the femoral stem 4, wherein the thickness of the coating is 5000 um, the porosity factor is 1080%, and the bonding strength of the coating is more than or equal to 25 MPa.

[0034] The prosthesis adopted in the disclosure is integrated, without any need to assemble components, eliminating problems such as abrasion between components and osteolysis, reducing inventory, leading to low cost, suitable for all kinds of large-scale or small-scale factory; the design of the femoral stem of the disclosure conforms to the femoral stem for geometric shape of femoral medullary cavity of more than 90% patients; the anteversion angle in the disclosure is 35 or 145180, and patients for surgery can choose appropriate specifications of prosthesis according to their own anteversion angle, which effectively shorten the operation time, reduce the pain of patients, and improve the success rate of the operation; Ti coating is sprayed on the outer surface of the proximal segment of the femoral stem 4 in the disclosure, enhancing biological compatibility of the prosthesis, and the strength and ductility and toughness match with human bone, which creates favorable conditions for bone cells and soft tissue ingrowth and proliferation, so as to achieve a perfect match, between the prosthesis and the patient's femora, especially suitable for developmental dysplasia of the hip (DDH patients with'congenital dislocation of the hip (CDH).

[0035] The above is the preferred embodiment of the disclosure, it should be pointed out that for those of ordinary skill in the art, some improvement and polishing can be made without departing from the principle of the disclosure, and these improvements should also be regarded as the scope of protection of the disclosure.