Lower limb length change experimental device in hip replacement

Abstract

The invention discloses a lower limb length change experiment device in hip joint replacement, which comprises an artificial pelvis and an artificial lower limb, and an artificial hip joint is arranged between the artificial pelvis and the artificial lower limb; the artificial hip joint comprises an artificial acetabular cup, a groove is formed in the bottom surface of the artificial acetabular cup, the groove is matched with an artificial femoral head, and different hip rotation centers are simulated by adjusting the spherical center space position of the artificial femoral head; the artificial hip joint further comprises an artificial femoral stem, the artificial lower limb is arranged on the artificial femoral stem in a sleeving mode, and different lower limb lengths are simulated by adjusting the sleeving length of the artificial lower limb and the artificial femoral stem. The experimental device for the length change of the lower limbs in the hip replacement has the advantages that the operation is simple, the universality is good, the influence of artificial hip joints with different sizes and models on the hip rotation center of the lower limbs and the length difference of the lower limbs of a patient can be analyzed in vitro, and reference opinions are provided for a doctor to adjust a test model in the operation.

Description

Technical Field

[0001] The invention relates to the technical field of analysis and testing platforms, and in particular to a lower limb length change experimental device during hip replacement surgery. Background Art

[0002] Total hip replacement is one of the most common orthopedic surgeries. It is a procedure that uses an artificial hip prosthesis to replace the terminally diseased or damaged hip joint. The artificial hip joint is usually composed of an acetabular cup, a liner, a ball head and a femoral stem prosthesis. The acetabular cup, ball head and femoral stem prosthesis vary in size and length. During surgery, the appropriate prosthesis should be selected according to the patient's actual bone age. Incorrect selection of the prosthesis can lead to complications of unequal length of the lower limbs, which will lead to biomechanical changes in the lower limbs and the lower back, and cause the patient to have a limping gait, compensatory pelvic tilt and scoliosis after surgery.

[0003] The complications of unequal length of lower limbs are mainly caused by the deviation of the hip rotation center and the abnormal length of the femoral prosthesis stem. If the effects of artificial prostheses (size and length of acetabular cup, femoral head and femoral stem) on the patient's hip rotation center and lower limb length are tested and analyzed during surgery, the risk is greater, the cost is higher, the cycle is longer, and it is not conducive to the doctor's adjustment of the trial model. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of the above-mentioned background technology and to provide an experimental device for the change of lower limb length during hip replacement surgery.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] An experimental device for lower limb length change during hip replacement surgery comprises: an artificial pelvis and an artificial lower limb, wherein an artificial hip joint is arranged between the artificial pelvis and the artificial lower limb; the artificial hip joint comprises an artificial acetabulum, which is engaged with the artificial pelvis, and a groove is provided on the bottom surface of the artificial acetabulum, wherein the groove is matched with an artificial femoral head, and different hip rotation centers can be simulated by adjusting the spatial position of the center of the sphere of the artificial femoral head; the artificial hip joint also comprises an artificial femoral stem, and the artificial lower limb is sleeved on the artificial femoral stem and fixed by bolts, and different lower limb lengths can be simulated by adjusting the sleeve length of the artificial lower limb and the artificial femoral stem.

[0007] As a further solution of the present invention: all outer surfaces of the artificial acetabular cup except the bottom surface are provided with gaskets, and the spatial position of the center of the sphere of the artificial femoral head can be adjusted by adjusting the number of the gaskets.

[0008] As a further solution of the present invention: the gasket includes a second gasket, a third gasket and a fourth gasket, the second gasket is arranged on the top surface of the artificial acetabular cup, and the number of the second gaskets is adjusted to adjust the height position of the center of the artificial femoral head; the third gasket is arranged on the left and right sides of the artificial acetabular cup, and the fourth gasket is arranged on the front and back sides, and the number of the third gasket and the fourth gasket is adjusted to adjust the plane position of the center of the artificial femoral head.

[0009] As a further solution of the present invention: the artificial femoral head is composed of a solid spherical segment and an internally threaded circular tube, and the end surface of the internally threaded circular tube is fixedly connected to the circular cross-section of the solid spherical segment.

[0010] As a further solution of the present invention: the artificial femoral head is threadedly connected to an artificial femoral head connecting rod, the artificial femoral head connecting rod is a cylindrical rod, the upper part of the artificial femoral head connecting rod is provided with an external thread, and the lower part is a smooth curved surface.

[0011] As a further solution of the present invention: the artificial lower limb is connected to an artificial femoral stem via bolts, and the artificial femoral stem is provided with a connecting rod through hole that is matched with the smooth curved surface at the lower part of the artificial femoral head connecting rod.

[0012] As a further solution of the present invention: the connecting rod through hole is a hole opened obliquely.

[0013] As a further solution of the present invention: the artificial femoral stem is provided with a limiting groove, and the limiting groove is provided with a limiting gasket.

[0014] As a further solution of the present invention: a plurality of first gaskets are arranged between the limiting gasket and the artificial lower limb, and the sleeve length of the artificial lower limb and the artificial femoral stem can be adjusted by adjusting the number of the first gaskets.

[0015] As a further solution of the present invention: an artificial femoral head fixing cover is fixed to the bottom surface of the artificial acetabular cup by bolts, and the artificial femoral head fixing cover is provided with a through hole matched with the artificial femoral head.

[0016] Beneficial effects of the present invention:

[0017] In the present invention, the lower limb length change experimental device during hip replacement surgery is simple to operate and has good versatility. It can analyze in vitro the effects of artificial hip joints of different sizes and models on the patient's lower limb hip rotation center and lower limb length difference, and provide reference opinions for doctors to adjust the trial model during surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Figure 1It is a structural schematic diagram of a lower limb length change experimental device in hip replacement surgery provided by the present invention;

[0020] Figure 2 It is a schematic diagram of a partial structural section of a lower limb length change experimental device in hip replacement surgery provided by the present invention;

[0021] Figure 3 yes Figure 2 The enlarged view of point A in the middle;

[0022] Figure 4 It is a schematic diagram of the structure explosion of a lower limb length change experimental device during hip replacement surgery provided by the present invention.

[0023] In the figure: 1. artificial hip joint; 101. first gasket; 102. limiting gasket; 103. second gasket; 104. third gasket; 105. fourth gasket; 106. artificial femoral head fixing cover; 107. artificial acetabulum; 108. artificial femoral head; 109. artificial femoral head connecting rod; 110. connecting rod through hole; 111. artificial femoral stem; 112. limiting groove; 2. artificial pelvis; 201. artificial acetabulum; 3. artificial lower limb; 301. femoral stem groove. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1 , Figure 4 As shown, the present invention is an experimental device for lower limb length change during hip replacement surgery, comprising: an artificial pelvis 2 and an artificial lower limb 3, wherein an artificial hip joint 1 is arranged between the artificial pelvis 2 and the artificial lower limb 3.

[0026] The artificial pelvis 2 is bilaterally symmetrical and includes two artificial acetabulums 201. The two artificial acetabulums 201 are also bilaterally symmetrically distributed. The artificial acetabulums 201 are square grooves, and a plurality of screw holes are arranged on the artificial acetabulums 201 for assembling the artificial hip joint 1. Two artificial hip joints 1 are also arranged, which are bilaterally symmetrically distributed. Accordingly, two artificial hip joints 1 are also arranged for each artificial hip joint, which are bilaterally symmetrically distributed.

[0027] See also Figure 2-Figure 3As shown, the artificial hip joint 1 includes an artificial acetabulum 107, which is engaged with the artificial pelvis 2, specifically in the artificial acetabulum 201. A groove is provided on the bottom surface of the artificial acetabulum 107, which is hemispherical and matched with an artificial femoral head 108. By adjusting the spatial position of the center of the sphere of the artificial femoral head 108, different hip rotation centers can be simulated.

[0028] Specifically, all outer surfaces of the artificial acetabular cup 107 except the bottom surface are provided with gaskets, and the number of gaskets is adjusted to adjust the center spatial position of the artificial femoral head 108. The gaskets are all square plates with uniform thickness, and the gaskets specifically include a second gasket 103, a third gasket 104 and a fourth gasket 105.

[0029] The second gasket 103 is arranged on the top surface of the artificial acetabular cup 107, and the number of the second gaskets 103 is adjusted to adjust the height position of the center of the ball of the artificial femoral head 108. The third gasket 104 is arranged on the left and right sides of the artificial acetabular cup 107, and the fourth gasket 105 is arranged on the front and back sides. The number of the third gasket 104 and the fourth gasket 105 is adjusted to adjust the plane position of the center of the ball of the artificial femoral head 108. The bottom surface of the artificial acetabular cup 107 is fixed with an artificial femoral head fixing cover 106 by bolts. The artificial femoral head fixing cover 106 is a square plate, and the square plate is provided with a through hole adapted to the artificial femoral head 108, and the through hole is spherical, so that the artificial femoral head 108 is assembled on the artificial acetabular cup 107.

[0030] Wherein, the artificial femoral head 108 is composed of a solid spherical segment and an internally threaded circular tube, and the end face of the internally threaded circular tube is fixedly connected to the circular cross section of the solid spherical segment. The spherical radius of the solid spherical segment of the artificial femoral head 108, the spherical radius of the hemispherical groove of the artificial acetabulum 107 and the spherical radius of the central spherical through hole of the artificial femoral head fixing cover 106 are the same, so that the solid spherical segment of the artificial femoral head 108 can rotate in the above-mentioned groove and through hole, and the movement of the human femoral head in the acetabulum can be simulated.

[0031] Moreover, the artificial femoral head 108 is also threadedly connected to an artificial femoral head connecting rod 109, which is a cylindrical rod. The upper portion of the artificial femoral head connecting rod 109 is provided with an external thread, and the lower portion is a smooth curved surface.

[0032] The artificial hip joint 1 also includes an artificial femoral stem 111. The artificial lower limb 3 is provided with a femoral stem groove 301 adapted to the artificial femoral stem 111. The artificial lower limb 3 is sleeved on the artificial femoral stem 111 so that the artificial femoral stem 111 can slide in the femoral stem groove 301. After sliding to a preset position, the artificial femoral stem 111 can be fixed to the artificial lower limb 3 by bolts. By adjusting the sleeve length of the artificial lower limb 3 and the artificial femoral stem 111, different lower limb lengths can be simulated.

[0033] Specifically, the artificial femoral stem 111 is provided with a connecting rod through hole 110 that is compatible with the smooth curved surface at the bottom of the artificial femoral head connecting rod 109 . The connecting rod through hole 110 is an obliquely opened hole, which facilitates adjustment of the embedded position of the artificial femoral head connecting rod 109 in the connecting rod through hole 110 .

[0034] See also Figure 3-Figure 4 As shown, the artificial femoral stem 111 is provided with a limiting groove 112, and the limiting groove 112 is an annular groove structure. The limiting groove 112 is provided with a limiting gasket 102, and the shape of the limiting gasket 102 is adapted to the limiting groove 112, so that the limiting gasket 102 can be inserted into the limiting groove 112 for fixation. After the limiting gasket 102 is inserted into the limiting groove 112, it will extend out of the surface of the artificial femoral stem 111, serving as a limiting mark. A plurality of first gaskets 101 are arranged between the limiting gasket 102 and the artificial lower limb 3, and the shape of the first gasket 101 is adapted to the artificial lower limb 3, so as to avoid interference with the insertion of the artificial femoral stem 111 into the femoral stem groove 301. The sleeve length of the artificial lower limb 3 and the artificial femoral stem 111 can be adjusted by adjusting the number of the first gaskets 101.

[0035] The inventors found that the risk of intraoperatively testing and analyzing the effects of artificial prostheses on the patient's hip rotation center and lower limb length is high, the cost is higher, the cycle is longer, and it is not conducive to the doctor's adjustment of the trial model. Therefore, in vitro research on the effects of artificial hip joints on the hip rotation center and lower limb length is a problem that needs to be solved.

[0036] When using the lower limb length variation experimental device in this hip replacement, first select a hip rotation center and lower limb length as preoperative data. The second pad 103, the 3rd pad 104, the 4th pad 105 and the artificial acetabular cup 107 are assembled. Specifically, select several 3rd pads 104 and the 4th pad 105 to be placed around the artificial acetabular cup 107, and use bolts that the artificial acetabular cup 107 is fastened in the artificial acetabulum 201. The internal threaded round tube of artificial femoral head 108 is passed through the through hole in the center of artificial femoral head fixed cover 106 again, and use bolts that artificial femoral head fixed cover 106 is fixed on the artificial acetabular cup 107 from the four corners, at this moment, the contact surface of artificial femoral head fixed cover 106 and artificial acetabular cup 107 fit, the through hole of artificial femoral head fixed cover 106 cooperates with artificial acetabular cup 107 grooves to form a spherical space, and artificial femoral head 108 is locked in the spherical space, to ensure that artificial femoral head 108 can rotate, and can not produce looseness again. Then, the end of the artificial femoral head connecting rod 109 with external threads is screwed into the internal threaded round tube of the artificial femoral head 108 and tightened, and the other end of the artificial femoral head connecting rod 109 is inserted into the connecting rod through hole 110, and the artificial femoral head connecting rod 109 is pressed and fixed in the connecting rod through hole 110 by bolts. Then, the limiting gasket 102 is inserted into the limiting groove 112, and the lower end of the artificial femoral stem 111 is inserted into the femoral stem groove 301, and one side of the limiting gasket 102 is close to the top of the femoral stem groove 301, and the artificial femoral stem 111 is pressed and fixed in the femoral stem groove 301 by bolts.

[0037] The artificial lower limb 3 is rotated and the dynamic trajectory of a certain point on the artificial lower limb 3 is recorded. The center position of the femoral head can be obtained by spatial spherical fitting, and the preoperative hip rotation center is recorded. The length from the preoperative rotation center to the capture point on the artificial lower limb 3 is temporarily recorded as the lower limb length.

[0038] The influence of the change of the hip rotation center and the length of the lower limbs on the change of the length of the lower limbs is analyzed by quantitatively changing the center of rotation of the hip and the length of the lower limbs. Specifically, the number of the second gasket 103, the third gasket 104, and the fourth gasket 105 around the artificial acetabular cup 107 is adjusted, and then the spatial position of the artificial acetabular cup 107 is changed. The thickness of the second gasket 103, the third gasket 104, and the fourth gasket 105 are uniform and the same, then the thickness of one gasket can be quantitatively calculated as the minimum amount of the spatial displacement of the artificial acetabular cup 107. The spatial position of the artificial acetabular cup 107 changes, and the spatial position of the center of the sphere of the artificial femoral head 108 changes accordingly, so the center of rotation of the hip changes. The first gasket 101 is inserted between the limiting gasket 102 and the femoral stem groove 301. The number of the first gaskets 101 is several, and the thickness is the same and uniform. By controlling the number of the first gaskets 101, the change of the length of the lower limbs caused by the change of the length of the femoral stem of the artificial hip joint is simulated.

[0039] After quantitatively changing the number of the first gasket 101, and changing the number of the second gasket 103, the third gasket 104, and the fourth gasket 105 around the artificial acetabular cup 107, shake the artificial lower limb 3 to obtain a new spatial position of the hip rotation center and the length of the lower limb. By comparing the position of the hip rotation center and the lower limb length before the number of gaskets is changed, the spatial position difference of the hip rotation center and the lower limb length difference can be obtained. Combined with the changed number of gaskets, it can assist doctors in analyzing the impact of the transformation of the hip rotation center and the change in the length of the femoral stem prosthesis after total hip replacement on the length of the lower limb (or human body movements), that is, in vitro simulation of the impact of artificial hip joints of different sizes and models (different acetabular cups, femoral heads and femoral stem prostheses) on the difference in length of both lower limbs, which is convenient for doctors to guide the operation, provide reference opinions for doctors to adjust the trial mold during the operation, and facilitate patients to achieve the purpose of equal length of both lower limbs after surgery. The experimental device for the change of lower limb length during hip replacement is simple to operate and has good versatility.

[0040] Working principle: adjust the number of the second gasket 103, the third gasket 104, and the fourth gasket 105 around the artificial acetabular cup 107, and then change the spatial position of the artificial acetabular cup 107. The thickness of the second gasket 103, the third gasket 104, and the fourth gasket 105 are uniform and the same, so the thickness of one gasket can be quantified as the minimum amount of spatial displacement of the artificial acetabular cup 107. The spatial position of the artificial acetabular cup 107 changes, and the spatial position of the center of the sphere of the artificial femoral head 108 changes accordingly, so the hip rotation center changes. Insert the first gasket 101 between the limiting gasket 102 and the femoral stem groove 301. The number of the first gaskets 101 is the same and uniform. By controlling the number of the first gaskets 101, the change in the length of the lower limb caused by the change in the length of the femoral stem of the artificial hip joint is simulated.

[0041] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope of the claims of the present invention.

Claims

1. An experimental device for measuring the length change of lower limbs during hip replacement surgery, characterized in that: include: An artificial pelvis (2) and an artificial lower limb (3), wherein an artificial hip joint (1) is arranged between the artificial pelvis (2) and the artificial lower limb (3); The artificial hip joint (1) comprises an artificial acetabulum (107), the artificial acetabulum (107) is engaged with the artificial pelvis (2), a groove is provided on the bottom surface of the artificial acetabulum (107), the groove is matched with an artificial femoral head (108), and different hip rotation centers are simulated by adjusting the spatial position of the center of the sphere of the artificial femoral head (108); The artificial hip joint (1) further comprises an artificial femoral stem (111), the artificial lower limb (3) is sleeved on the artificial femoral stem (111) and fixed by bolts, and different lower limb lengths can be simulated by adjusting the sleeve length of the artificial lower limb (3) and the artificial femoral stem (111).

2. The lower limb length change experimental device during hip replacement surgery according to claim 1, characterized in that: The outer surfaces of the artificial acetabulum (107) other than the bottom surface are all provided with gaskets, and the spatial position of the center of the sphere of the artificial femoral head (108) can be adjusted by adjusting the number of the gaskets.

3. The experimental device for measuring the length change of lower limbs during hip replacement surgery according to claim 2, characterized in that: The gasket comprises a second gasket (103), a third gasket (104) and a fourth gasket (105); the second gasket (103) is arranged on the top surface of the artificial acetabular cup (107); the number of the second gaskets (103) is adjusted to adjust the height position of the center of the ball of the artificial femoral head (108); the third gaskets (104) are arranged on the left and right sides of the artificial acetabular cup (107); the fourth gaskets (105) are arranged on the front and rear sides; the number of the third gaskets (104) and the fourth gaskets (105) are adjusted to adjust the plane position of the center of the ball of the artificial femoral head (108).

4. The experimental device for measuring the length change of lower limbs during hip replacement surgery according to claim 1, characterized in that: The artificial femoral head (108) is composed of a solid spherical segment and an internally threaded circular tube, and the end surface of the internally threaded circular tube is fixedly connected to the circular cross section of the solid spherical segment.

5. The experimental device for measuring the change in lower limb length during hip replacement surgery according to claim 3, characterized in that: The artificial femoral head (108) is threadedly connected to an artificial femoral head connecting rod (109), and the artificial femoral head connecting rod (109) is a cylindrical rod. The upper part of the artificial femoral head connecting rod (109) is provided with an external thread, and the lower part is a smooth curved surface.

6. The experimental device for measuring the change in lower limb length during hip replacement surgery according to claim 5, characterized in that: The artificial lower limb (3) is connected to an artificial femoral stem (111) via bolts, and the artificial femoral stem (111) is provided with a connecting rod through hole (110) adapted to the smooth curved surface at the bottom of the artificial femoral head connecting rod (109).

7. The experimental device for measuring the change in lower limb length during hip replacement surgery according to claim 6, characterized in that: The connecting rod through hole (110) is a hole opened obliquely.

8. The lower limb length change experimental device in hip replacement surgery according to claim 6, characterized in that: The artificial femoral stem (111) is provided with a limiting groove (112), and the limiting groove (112) is provided with a limiting gasket (102).

9. The lower limb length change experimental device during hip replacement surgery according to claim 8, characterized in that: A plurality of first gaskets (101) are arranged between the limiting gasket (102) and the artificial lower limb (3), and the sleeve length of the artificial lower limb (3) and the artificial femoral stem (111) is adjusted by adjusting the number of the first gaskets (101).

10. The lower limb length change experimental device during hip replacement surgery according to claim 3, characterized in that: An artificial femoral head fixing cover (106) is fixed to the bottom surface of the artificial acetabulum (107) by means of bolts, and the artificial femoral head fixing cover (106) is provided with a through hole matched with the artificial femoral head (108).

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