This application claims priority to Chinese Patent Application Ser. No. CN2019110719964 filed on 5 Nov. 2019.

TECHNICAL FIELD

The invention relates to a medical artificial joint prosthesis, in particular a bionic artificial hip joint.

BACKGROUND ART

The human hip joint is the joint formed by the thigh bone (femur) and the pelvis. The hip joint is a spherical joint that includes a spherical femoral head and a bowl-shaped acetabulum. The spherical outer surface and the bowl inner surface are both covered with smooth cartilage, and the synovial membrane secretes mucus to minimize friction. When the hip joint develops a disease, the cartilage is no longer smooth, and the synovial sac shrinks due to inflammation, so the hip joint can no longer function as usual. When the hip joint leads to pain, stiffness or deformation due to degeneration, disease, or trauma, or even lead to inconvenient movement, and the symptoms cannot be relieved by drugs or other treatments, replacement of an artificial hip joint will generally be arranged by surgery for the patient, so that the patient can restore his daily activity ability.

The artificial hip joint prosthesis imitates the structure of the human hip joint, including a prosthetic metal cup used to replace the acetabulum and a spherical end used to replace the femoral head, wherein the spherical end is fixed on the femoral stem. The lower end of the femoral stem is provided with a bolt, and the femoral stem is fixed on the human femur by inserting the bolt into the femoral medullary cavity. The spherical end forms a rotating mechanism with the acetabulum or the prosthetic metal cup to realize the bending and movement of the femur.

In the existing artificial hip replacement surgery, it is possible to choose a bowl-shaped acetabulum for replacement, or a femoral stem with a spherical end for replacement according to the specific injury and condition, or both at the same time. But after a period of time, the tightness between the femoral stem and the femur on which it is located gradually decreases, and the two will become loose. Under the action of body pressure, the femoral stem and the bolt on it will sink further, causing the two legs of the patient to have different lengths, which will further affect the normal physiological function of the hip joint.

In view of the above problems, the inventor has conducted in-depth research on the existing bionic artificial hip joints, and found that the bolts on the existing femoral stems are all straight rod-shaped. In order to insert the bolts into the medullary cavity of the femur, the doctor needs to drill a deep hole in the middle of the patient's medullary cavity. For the hole, a vertical hole is naturally preferred. However, the human femur is physiologically curved, not truly straight rod-shaped. Thus, while preparing for holes required for installing existing artificial hip joints, it is necessary to destroy not only the cancellous bone, but also part of the cortex, which reduces the overall strength of the femur. Moreover, the straight rod-shaped structure mainly focuses on the inner condyle regarding bearing capacity of the vertical force.

Moreover, in order to install the existing artificial hip joint, it is necessary to remove the femoral head, femoral neck and part of the cortex on the greater trochanter, which weakens the connection between the corpus femoris and the artificial hip joint.

In addition, the existing artificial hip joint and the corpus femoris are in a hard-to-hard connection, lacking a buffer mechanism. As such, any attempt to walk will result in a rigid impact, which will inevitably lead to more serious wear and tear over the years.

These are the direct reasons leading to the disadvantages of bionic artificial hip joint in the existing technology, such as insufficient durability, insufficient strength, and susceptibility to deformation of the connection with the femur.

Contents of the Invention

In order to overcome the above problems, the present inventors have conducted intensive research and devised a bionic artificial hip joint. The artificial hip joint includes a femoral stem located above corpus femoris, and a convex force-bearing part is provided on the femoral stem. The force-bearing part abuts against the inner side of the cortex on greater trochanter and bears a part of the longitudinal stress. The hollow design of the force-bearing part is convenient for bone grafting, so that the prosthesis and the cortex on greater trochanter can be integrated to improve the stability of the connection between the bionic artificial hip joint and corpus femoris. In the middle and lower part of the femoral stem, there is a design with a predetermined curvature. This design enables the femoral stem to be inserted into the corpus femoris along the physiological curvature of the femoral medullary cavity. Therefore, the artificial hip joint and the corpus femoris are tightly connected as a whole without excessive destruction of the substantiacompactain the femoral medullary cavity, which makes the strength of corpus femoris after surgery higher, and can also make the corpus femoris and the femoral stem more tightly fixed, not easy to loosen and break. As such, the present invention is provided.

Specifically, the object of the present invention is to provide a bionic artificial hip joint which includes a femoral stem1located above corpus femoris;

a convex force-bearing part2is provided on the femoral stem1;

the femoral stem1can be combined with a cortex on greater trochanter via the force-bearing part2.

The force-bearing part2abuts against the inner side of the cortex on greater trochanter.

Wherein the force-bearing part2can be integrated with the cortex on greater trochanter.

Wherein the force-bearing part2is located on a side of the femoral stem1, and has an arc-shaped outside.

Wherein a reserved space21capable of containing bone cement is provided inside the force-bearing part2.

Wherein a hole22communicating with the reserved space21is opened via a surface of the force-bearing part2.

Preferably, the surface of the force-bearing part2is net-shaped.

Wherein the surface of the force-bearing part2is a net-shaped hard shell23.

The hard shell23is detachably fixed on the force-bearing part2.

Wherein, in the force-bearing part2, a support ridge24is provided on the inner side of the hard shell23to support the hard shell23.

Wherein, a spherical end3is arranged obliquely above the femoral stem1.

A bolt4is provided under the femoral stem1.

Preferably, both the spherical end3and the bolt4are detachably mounted on the femoral stem1.

Wherein the main part of the bolt4is in a shape of a flat rod with a predetermined curvature, and the predetermined curvature is suitably matched with the physiological curvature in the femoral medullary cavity.

Wherein the bolt4installed on the femoral stem1can be installed on the femoral stem1again after rotating 180 degrees around its own axis.

Wherein the femoral stem1is provided with a lower slot hole11for accommodating the bolt4.

The bolt4includes a main body part in a shape of a flat rod and a plug end41at the top.

The cross-sectional shapes of the plug end41and the lower slot hole11are both centrally symmetrical.

Preferably, the cross-sectional shapes of both the plug end41and the lower slot hole11are rectangular or waist-shaped.

The beneficial effects of the present invention include the following:

(1) The femoral stem in the bionic artificial hip joint provided by the present invention can be inserted into the corpus femoris along the physiological curvature of the femoral medullary cavity, so as to be in close contact with the corpus femoris, and the stability of the connection between the bionic joint and the corpus femoris and the strength of the femoral shaft are improved by destroying the corpus femoris as little as possible;

(2) The design of the plug connection in the bionic artificial hip joint provided by the present invention can correspond to the physiological curvature of the femoral medullary cavity on the two femurs by changing the angle of installation, that is, a femoral stem with a physiological curvature can be correspondingly installed in any femoral medullary cavity, without the need to prepare two sets of different femoral stems;

(3) According to the bionic artificial hip joint provided by the present invention, a force-bearing part capable of abutting against the inner side of the cortex on greater trochanter is provided on a side of the femoral stem, thereby increasing the longitudinal load of the femoral stem; filling the force-bearing part with cancellous bone, bone strips or stem cells will facilitate the integral growth of the femoral stem and the greater trochanter, thus further improving the stability of the femoral stem while providing supporting force for the femoral stem in another direction.

