A type of femoral stem for veterinary hip joint

Abstract

This invention discloses a femoral stem for veterinary hip joints, comprising a distal cone, a stem body, and a proximal segment connected in sequence. The surfaces of the distal cone and stem body are provided with several grooves, the length of which is aligned with the insertion direction of the femoral stem. The proximal segment has a neck on its proximal medial side and a locking pin on its proximal lateral side, used to connect the proximal segment to the femoral bone. The grooves on the surfaces of the distal cone and stem body effectively disperse the pressure within the femoral medullary cavity during prosthesis insertion, facilitating clinical operation. The locking pin fixation of the proximal segment provides dual stability to the femoral stem, effectively improving the stability in all directions and overall anti-rotation performance after prosthesis implantation.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a femoral stem for a veterinary hip joint. Background Technology

[0002] Veterinary orthopedic instruments are tools and equipment specifically designed for orthopedic surgery in animals. With increasing emphasis on pet health and welfare, the demand for treatment of pet orthopedic diseases such as fractures and arthritis has significantly increased, driving the rapid growth of the veterinary orthopedic instrument market.

[0003] Surgical steps for veterinary hip joint femoral stem prosthesis: After removing the femoral head, the femoral stem prosthesis is implanted into the femoral medullary cavity along the medial condyle and fixed; the superficial bone tissue of the acetabulum is removed, and the acetabular cup is fixed inside the acetabulum. These two procedures work together to achieve the physiological function of the hip joint.

[0004] In existing animal femoral stem designs, the distal cone has a nearly circular cross-section. This regularly shaped distal cone cross-section often does not conform to the physiological structure of the femoral medullary cavity, resulting in less contact surface and larger gaps between the prosthesis and bone tissue. Ultimately, this leads to insufficient anti-rotation performance of the femoral stem. Pets are naturally active, subjecting the femoral stem to multi-directional forces; insufficient product stability can cause rotational loosening of the femoral stem. Utility Model Content

[0005] The purpose of this utility model is to provide a femoral stem for a veterinary hip joint, so as to at least partially solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A femoral stem for a veterinary hip joint includes a distal cone, a stem body, and a proximal segment connected in sequence. The surfaces of the distal cone and the stem body are provided with a plurality of grooves, the length direction of which is arranged along the insertion direction of the femoral stem. The proximal end of the proximal segment has a neck on its inner side and a locking pin is provided on its outer side. The locking pin is used to connect the proximal segment and the femoral bone.

[0008] Optionally, the proximal segment has a locking hole extending from the proximal end of the proximal segment to the outer sidewall of the proximal segment, and the locking pin passes through the locking hole.

[0009] Optionally, the locking pin includes a head and a rod, with a stepped structure between the head and the rod. The locking hole includes a first locking hole and a second locking hole. The head of the locking pin is located in the first locking hole, and the rod passes through the second locking hole. A radial gap is provided between the head and the first locking hole, and a radial gap is provided between the rod and the second locking hole.

[0010] Optionally, the rod portion includes a threaded section and a smooth section, the nail head has a smooth outer surface, and the smooth section of the rod portion is clearance-fitted with the second locking hole.

[0011] Optionally, the angle between the axis of the locking hole and the central axis of the handle body is less than 45°.

[0012] Optionally, the cross-section of the handle is D-shaped, and the outermost edges of the front and rear sides of the cross-section of the handle are close to the outer side of the handle.

[0013] Optionally, at least one groove is provided on each of the front side, rear side, inner side, and outer side.

[0014] Optionally, the projection of the groove along its length is arc-shaped.

[0015] Optionally, the projection of the groove in the handle portion along the groove length direction is arc-shaped, and the projection of the groove in the distal cone portion along the groove length direction is straight-line.

[0016] Optionally, the depth of the trench varies from shallow to deep and then back to shallow along its length from the proximal end to the distal end.

[0017] Optionally, the projection of the groove in the groove width direction is an arc shape.

[0018] Optionally, the outer surface of the proximal segment is provided with a porous coating.

[0019] Optionally, both the distal cone and the stem are connected to the femoral medullary cavity using bone cement.

[0020] The beneficial effects of this utility model are as follows: The distal cone and stem of this utility model are provided with several grooves, which can effectively disperse the pressure brought by the cavity when the prosthesis is inserted into the femoral medullary cavity, which facilitates clinical operation; the proximal segment is fixed with locking screws, which can achieve dual stability of the femoral stem and effectively improve the stability in all directions and the overall anti-rotation performance of the prosthesis after implantation. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a front view of the femoral stem of the veterinary hip joint according to an embodiment of the present invention;

[0023] Figure 2This is a top view of the femoral stem of the veterinary hip joint according to an embodiment of the present invention;

[0024] Figure 3 for Figure 2 AA section view;

[0025] Figure 4 for Figure 1 BB section view;

[0026] Figure 5 for Figure 1 CC section view;

[0027] Figure 6 for Figure 1 DD sectional view.

[0028] in:

[0029] 1. Distal cone;

[0030] 2. Handle; 21. Front side; 22. Rear side; 23. Inner side; 24. Outer side;

[0031] 3. Proximal segment; 31. Neck; 32. Locking hole; 321. First locking hole; 322. Second locking hole;

[0032] 4. Trench;

[0033] 5. Locking pin; 51. Pin head; 52. Bar. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0035] This embodiment provides a femoral stem for veterinary hip joints, used in animal hip replacement surgery; the femoral stem is inserted into the femoral medullary cavity for fixation and reconstruction of hip joint physiological function. Figures 1-6 As shown, the femoral stem of the veterinary hip joint includes a distal cone 1, a stem body 2 and a proximal segment 3 connected in sequence. The surfaces of the distal cone 1 and the stem body 2 are provided with a number of grooves 4. The length direction of the grooves 4 is set along the insertion direction of the femoral stem. The proximal medial side of the proximal segment 3 is provided with a neck 31. The proximal lateral side of the proximal segment 3 is provided with a locking pin 5, which is used to connect the proximal segment 3 and the femoral bone.

[0036] In this embodiment, the surfaces of the distal cone 1 and the stem 2 are provided with several grooves 4, which can effectively disperse the pressure brought by the femoral stem when it is inserted into the femoral medullary cavity, making clinical operation convenient; the proximal segment 3 is fixed with locking screws 5, which can achieve dual stability of the femoral stem and effectively improve the stability in all directions and the overall anti-rotation performance after the prosthesis is implanted.

[0037] Specifically, such as Figure 3 As shown, a locking hole 32 extends from the proximal end of the proximal segment 3 to the lateral sidewall of the proximal segment 3, and a locking pin 5 is inserted into the locking hole 32. The locking pin 5 obliquely protrudes from the sidewall of the proximal segment 3 through the locking hole 32 and extends laterally. The locking pin 5 obliquely connects the proximal segment 3 and the femoral bone, which is beneficial to the stability of the connection between the two.

[0038] Furthermore, the locking pin 5 includes a pin head 51 and a rod portion 52, with a stepped structure between the pin head 51 and the rod portion 52. The locking hole 32 includes a first locking hole 321 and a second locking hole 322. The pin head 51 of the locking pin 5 is located in the first locking hole 321, and the rod portion 52 of the locking pin 5 passes through the second locking hole 322. A radial gap is provided between the pin head 51 and the first locking hole 321, and a radial gap is provided between the rod portion 52 and the second locking hole 322. In this embodiment, the outer diameter of the pin head 51 is larger than the outer diameter of the rod portion 52, and the transition between the pin head 51 and the rod portion 52 forms a stepped structure. The diameter of the first locking hole 321 is larger than the diameter of the second locking hole 322. Correspondingly, the transition between the first locking hole 321 and the second locking hole 322 forms a stepped structure. The pin head 51 is located in the first locking hole 321. The stepped structure can restrict the movement of the pin head 51 towards the femoral bone, thereby restricting the locking position of the locking pin 5.

[0039] Optionally, the rod portion 52 includes a threaded section 521 and a smooth section 522, and the screw head 51 has a smooth outer surface. The threaded section 521 of the rod portion 52 is driven into the femoral bone and connects with it; the smooth section 522 of the rod portion 52 is clearance-fitted with the second locking hole 322. A radial gap is provided between the screw head 51 and the first locking hole 321, and the clearance fit between the smooth section 522 of the rod portion 52 and the second locking hole 322 enables micro-movement during femoral stem implantation, allowing the femoral stem to be fixed in an accurate position.

[0040] Optionally, such as Figure 3 As shown, the angle α between the axis of the locking hole 32 and the central axis of the handle 2 is less than 45°, which can more effectively distribute gravity.

[0041] Specifically, such as Figure 5As shown, the cross-section of the stem 2 is D-shaped. The D-shaped cross-section more closely resembles the physiological structure of the femoral medullary cavity, resulting in a larger contact area between the distal cone 1 and the stem 2 and the femoral medullary cavity, leading to more uniform force distribution. Furthermore, the distance between the anterior side 21 and the posterior side 22 of the stem 2 gradually decreases from the outer side to the inner side of the stem 2, causing the moment of inertia of the stem 2's cross-section to move towards the outer side, resulting in a larger moment of inertia and a stronger ability to overcome rotational torque. The gradual decrease in cross-section size from proximal to distal in the stem 2 makes the femoral stem structure more closely resemble the skeletal morphology. The excellent contact method, optimized structure, and enhanced moment of inertia of this embodiment all contribute to improving the anti-rotational performance of the femoral stem. The cross-section of the distal cone 1 is similar in shape to the cross-section of the stem 2.

[0042] Optionally, such as Figure 3-5 As shown, the anterior side 21, posterior side 22, medial side 23, and lateral side 24 of the stem 2 and distal cone 1 are each provided with at least one groove 4. The groove 4 on each side can disperse the intracavitary pressure during prosthesis insertion on each of the four sides. Furthermore, the groove 4 significantly increases the contact area between the prosthesis and the medullary cavity. In this embodiment, bone cement is filled between the stem 2 and the distal cone 1 and the medullary cavity; the groove 4 also increases the holding force of the bone cement on the femoral stem, preventing rotation and improving the stability of the femoral stem.

[0043] In this embodiment, as Figure 3 and Figure 4 As shown, the groove 4 is arc-shaped along its length, and the radius R1 of the arc along the length of the groove 4 is 150-200 mm. Figure 2 As shown, the length L2 of the groove 4 in the longitudinal direction accounts for 50% to 75% of the total length L1 of the distal cone 1 and the stem 2 in the longitudinal direction. This design can effectively disperse the pressure brought into the femoral medullary cavity when the femoral stem prosthesis is inserted, which facilitates clinical operation.

[0044] In other embodiments, the groove 4 on the handle 2 is arc-shaped along its length, and the groove 4 on the distal cone 1 is straight along its length. In the length direction, the groove 4 on the handle 2 communicates with the groove 4 on the distal cone 1, and the connection between the groove 4 on the handle 2 and the groove 4 on the distal cone 1 is tangent.

[0045] Optionally, such as Figure 3 and Figure 4 As shown, the depth of groove 4 gradually increases from the proximal end of the femoral stem to the distal end and then gradually decreases. In this embodiment, the depth of groove 4 ranges from 0.2 to 0.5 mm.

[0046] Specifically, such as Figure 5As shown, the cross-section of the bottom of groove 4 is arc-shaped. In this embodiment, groove 4 significantly increases the contact area between the femoral stem and the medullary cavity, increases the holding force of bone tissue on the femoral stem, and improves the stability of the femoral stem. In this embodiment, the radius R2 of the arc at the bottom of groove 4 is 1-2 mm.

[0047] Specifically, such as Figure 6 As shown, the cross-section of the proximal segment 3 is rectangular, and the width of the cross-section of the proximal segment 3 in the front-to-back direction is smaller than the width in the inner-to-outer direction; all four corners of the cross-section of the proximal segment 3 are rounded, and the radii of the two outer rounded corners are smaller than the radii of the two inner rounded corners.

[0048] Specifically, the outer surface of the proximal segment 3 is coated with a porous structure. After the porous structure coating is applied to the outer surface of the proximal segment 3, the surface is rough, and the presence of micropores facilitates bone ingrowth, improving the connection between the prosthesis and the femoral medullary cavity. The distal cone 1 has a low-notch structure at its end, which facilitates the insertion of the femoral stem into the medullary cavity.

[0049] Both the distal cone 1 and the stem 2 are connected to the femoral medullary cavity using bone cement. In this embodiment, after the femoral stem is inserted, the distal cone 1 and the stem 2, made of bone cement, can adhere tightly to the surface of the cancellous bone within the medullary cavity, thus achieving excellent filling effect. Furthermore, the simultaneous use of bone cement and a porous coating on the same femoral stem in conjunction with the medullary cavity allows for initial stable fixation of the femoral stem using bone cement and locking screws 5. After a certain period of implantation, the porous coating can grow into the medullary tissue within the porous coating to achieve biological fixation, ensuring the long-term stability of the femoral stem implantation.

[0050] Optionally, such as Figure 2 As shown, the cross-section of the femoral stem 2 and distal cone 1 gradually decreases from large to small from proximal to distal. The proximal segment 3 transitions to the stem 2 via a rounded arc. This design makes the prosthesis structure more closely resemble the skeletal morphology, and the streamlined appearance better meets the requirements of animal mechanics.

[0051] Specifically, such as Figure 3 As shown, the distance L3 from the intersection of the central axis of the distal cone 1 and the central axis of the neck 31 to the end of the distal cone 1 accounts for 50% to 70% of the projected length L of the femoral stem on the central axis of the distal cone 1. This design makes the structural features of the three parts of the stem 2, neck 31 and distal cone 1 evenly distributed, and the overall appearance of the femoral stem is aesthetically pleasing.

[0052] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the system or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0053] Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0054] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0055] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0056] Finally, it should be noted that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A veterinary hip femoral stem, characterized by: It includes a distal cone, a stem, and a proximal segment connected in sequence. The surfaces of the distal cone and the stem are provided with a number of grooves. The length direction of the grooves is set along the insertion direction of the femoral stem. The proximal medial side of the proximal segment is provided with a neck. The proximal lateral side of the proximal segment is provided with a locking pin. The locking pin is used to connect the proximal segment and the femoral bone.

2. The veterinary hip femoral stem of claim 1, wherein: The proximal segment has a locking hole extending from the proximal end of the proximal segment to the outer sidewall of the proximal segment, and the locking pin passes through the locking hole.

3. The femoral stem for veterinary hip joints according to claim 2, characterized in that: The locking pin includes a head and a rod, with a stepped structure between the head and the rod. The locking hole includes a first locking hole and a second locking hole. The head of the locking pin is located in the first locking hole, and the rod passes through the second locking hole. There is a radial gap between the head and the first locking hole, and a radial gap between the rod and the second locking hole.

4. The femoral stem for veterinary hip joints according to claim 3, characterized in that: The rod portion includes a threaded section and a smooth section, the nail head has a smooth outer surface, and the smooth section of the rod portion is clearance-fitted with the second locking hole.

5. The femoral stem for a veterinary hip joint according to any one of claims 2-4, characterized in that: The angle between the axis of the locking hole and the central axis of the handle is less than 45°.

6. The femoral stem for veterinary hip joints according to claim 1, characterized in that: The cross-section of the handle is D-shaped, and the distance between the front and rear sides of the handle gradually decreases from the outer side of the handle to the inner side of the handle. And / or, the front side, rear side, inner side and outer side are each provided with at least one of the grooves.

7. The femoral stem for veterinary hip joints according to claim 1, characterized in that: The depth of the groove gradually increases from the proximal end of the femoral stem to the distal end of the femoral stem and then gradually decreases.

8. The femoral stem for veterinary hip joints according to claim 1, characterized in that: The cross-section of the bottom of the trench is arc-shaped.

9. The femoral stem for veterinary hip joints according to claim 1, characterized in that: The outer surface of the proximal segment is provided with a porous coating.

10. The femoral stem for a veterinary hip joint according to claim 9, characterized in that: Both the distal cone and the stem are connected to the femoral medullary cavity using bone cement.

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