Femoral intramedullary nail with adjustable angle

Abstract

The invention provides an angle-adjustable femoral intramedullary nail, which belongs to the technical field of orthopedic implants, and comprises a main nail used for being implanted into a longitudinal medullary cavity of a femur, and the main nail is provided with an inclined directional hole; the guide sleeve assembly comprises a plurality of guide sleeves, the guide sleeves can penetrate through and be fixed in the directional holes, inclined holes are formed in the guide sleeves, and when different guide sleeves are fixed in the directional holes, the included angles between the center lines of the inclined holes and the longitudinal direction of the main nail are different; the lag screw is arranged in the inclined hole of the guide sleeve in a penetrating mode, and the center line of the lag screw coincides with the axis of the guide sleeve. The guide sleeve is used for guiding to replace a main nail to guide the lag screw, and a more flexible low-cost accessory is used for replacing a high-cost main piece, so that the main nail of one specification can form various different included angles with the lag screw, and the main nail can be immediately matched with the requirements of a patient clinically to achieve an optimal postoperative effect; and meanwhile, the inventory cost and the turnover cost can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of orthopedic implants, and in particular relates to an angle-adjustable femoral intramedullary nail. Background Art

[0002] Femoral intramedullary nailing is the preferred treatment option for intertrochanteric combined femoral shaft fractures. In view of the differences in patients' bones, lag screws are implanted with multiple neck-shaft angles. Currently, one main nail cannot match lag screws with multiple neck-shaft angles. Therefore, the main nails need to be divided into different angle specifications for lag screws implanted at different neck-shaft angles to meet the different needs of patients and clinical needs. Therefore, medical device manufacturers always have a large inventory of main nails of various specifications.

[0003] At present, during each operation, multiple specifications of main nails need to be sent to the hospital for doctors to choose from. Therefore, the stocking order will place an order for all specifications of main nails with multiple neck-shaft angles, which consumes a lot of raw materials, has a long processing cycle, and requires many tooling specifications (occupying the tooling inventory area). The time for production changeover and debugging of multiple specifications increases, and the risk of defective products caused by debugging increases. At the same time, due to the high cost of intramedullary nail products and the differences in the consumption cycles of main nails of different specifications, a large number of main nails of different specifications in stock will result in high backlog costs, which poses a great challenge to production capacity arrangement. In addition, the turnover of main nails of multiple specifications also requires a lot of transportation costs. Therefore, it is easy to increase costs in all aspects if multiple specifications of main nails are always prepared for one operation. Therefore, there is an urgent need for an angle-adjustable femoral intramedullary nail to solve the above problems. Summary of the invention

[0004] In view of this, the present invention aims to propose an angle-adjustable femoral intramedullary nail, so that a main nail of one specification can form a variety of different angles with the tension screw, which can be instantly matched to the patient's needs in clinical practice to achieve the best postoperative effect, while effectively reducing inventory costs and turnover costs.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows: An angle-adjustable femoral intramedullary nail comprises: A main nail, which is used for implantation into the longitudinal medullary cavity of the femur, and the main nail is provided with an oblique directional hole; A guide sleeve assembly, comprising a plurality of guide sleeves, wherein the guide sleeves can be inserted into and fixed in the directional hole, wherein an oblique hole is provided in the guide sleeve, and when different guide sleeves are fixed in the directional hole, the central line of the oblique hole has a different angle with the longitudinal direction of the main nail; A tension screw is inserted into the inclined hole, and a center line of the tension screw coincides with an axis line of the guide sleeve.

[0006] Furthermore, the guide sleeve includes a tubular body and a flange, the flange is arranged at one end of the tubular body, the tubular body is inserted into the main nail, the flange is attached to the outer surface of the main nail, a screw hole is arranged on the flange, and the flange is locked and fixed to the main nail by a fixing nail inserted through the screw hole.

[0007] Furthermore, the tubular body and the flange are integrally formed.

[0008] Furthermore, a groove is provided on the outer edge of the directional hole, and when the flange is embedded in the groove, the outer surface of the flange does not exceed the surface around the groove.

[0009] Furthermore, the flange is engraved with an angle value of the angle between the center line of the inclined hole and the longitudinal direction of the main nail.

[0010] Furthermore, a first guide pin hole is provided in the longitudinal center of the main nail, and a second guide pin hole is provided on the tubular body. When the guide sleeve is inserted into the inclined hole, the center line of the first guide pin hole coincides with the center line of the second guide pin hole, and the diameter of the first guide pin hole is less than or equal to the diameter of the second guide pin hole.

[0011] Furthermore, the tension screw is provided with an anti-rotation groove, and the main nail is provided with an anti-rotation nail, and the anti-rotation nail can extend into the anti-rotation groove.

[0012] Furthermore, the anti-rotation nail includes a nut and a polished rod, wherein the nut is threadedly connected in the main nail and extends longitudinally along the main nail.

[0013] Furthermore, the anti-rotation groove extends in a long strip shape along the length direction of the tension screw.

[0014] Furthermore, the main nail includes a proximal end, a middle section and a distal end, the proximal end of the main nail is detachably mounted with a tail cap, the distal end of the main nail is radially provided with a locking hole, and a locking nail is detachably mounted in the locking hole.

[0015] Beneficial effects of the present invention: The angle-adjustable femoral intramedullary nail of the present invention utilizes a guide sleeve to guide instead of the main nail guide tension screw, and uses a more flexible low-cost accessory guide sleeve to replace the high-cost main nail. The outer surface dimensions of different guide sleeves are completely consistent, and are all compatible with the same main nail. The center lines of the oblique holes of different guide sleeves have different angles with the longitudinal direction of the main nail. Different guide sleeves form a guide sleeve assembly. In order to match the patient's neck-shaft angle, only one set of guide sleeve assemblies, a main nail and a tension screw are needed. Compared with the original method of setting directional holes of different angles on the main nail, the number of main nails required for surgery is greatly reduced, greatly shortening the stocking cycle; with the reduction in the stocking of main nails, the site occupation of warehousing and logistics is effectively reduced, saving the circulation costs of warehousing and outbound. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 This is a schematic structural diagram of an angle-adjustable femoral intramedullary nail according to an embodiment of the present invention; Figure 2 A partial cross-sectional view of an angle-adjustable femoral intramedullary nail according to an embodiment of the present invention; Figure 3 is a cross-sectional view of a main nail according to an embodiment of the present invention; Figure 4 This is a schematic structural diagram of a guide sleeve according to an embodiment of the present invention; Figure 5 is a cross-sectional view of a guide sleeve according to an embodiment of the present invention; Figure 6 This is a schematic structural diagram of a lag screw according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of an anti-rotation pin according to an embodiment of the present invention; Figure 8 It is a schematic diagram of the coordinated installation of the tension screw and the guide sleeve according to an embodiment of the present invention.

[0017] Description of reference numerals: 1. Main nail; 11. First guide pin hole; 12. Orientation hole; 13. Groove; 14. Interlocking hole; 2. guide sleeve; 21. tubular body; 22. flange; 23. oblique hole; 24. screw hole; 25. second guide pin hole; 3. Lag screw; 31. Threaded end; 32. Fitting end; 33. Anti-rotation groove; 4. Tail cap; 5. Fixing nail; 6. Locking nail; 7. Anti-rotation nail; 71. Nut; 72. Plain rod. DETAILED DESCRIPTION

[0018] The guide pin hole 11 is aligned with the guide pin and implanted into the longitudinal medullary cavity of the femur along the guide pin. The proximal end of the main nail 1 is provided with an oblique directional hole 12, and the angle between the center line of the directional hole 12 and the axis of the first guide pin hole 11 can be a certain angle value of 120°-130°, and the outer edge of the directional hole 12 is provided with a groove 13.

[0019] like Figure 4 As shown, the guide sleeve 2 includes a tubular body 21 and a flange 22. The tubular body 21 and the flange 22 are integrally formed, and the flange 22 is arranged at one end of the tubular body 21. The tubular body 21 is inserted into the directional hole 12 of the main nail 1, and the flange 22 is attached to the outer surface of the main nail 1. Specifically, in this embodiment, when the guide sleeve 2 is installed in the directional hole 12, the flange 22 is embedded in the groove 13, and the outer surface of the flange 22 does not exceed the surface around the groove 13, which can play a role of smooth transition and effectively reduce irritation to soft tissue.

[0020] In this embodiment, the cross section of the directional hole 12 is an oblong shape, and the inner wall of the directional hole 12 and the outer wall of the tubular body 21 are in contact with each other, so that the tubular body 21 of the guide sleeve 2 also has an oblong cylindrical structure.

[0021] The flange 22 is provided with a screw hole 24, and the flange 22 is locked and fixed on the main nail 1 by the fixing nail 5 passing through the screw hole 24. In this embodiment, the screw hole 24 is a countersunk hole, and when the fixing nail 5 locks the flange 22 on the main nail 1, the head of the fixing nail 5 sinks into the screw hole 24, thereby reducing irritation to soft tissue.

[0022] The tubular body 21 of the guide sleeve 2 is provided with a second guide needle hole 25. When the guide sleeve 2 is inserted into the directional hole 12 of the main nail, the center line of the first guide needle hole 11 coincides with the center line of the second guide needle hole 25. In particular, the diameter of the second guide needle hole 25 is not less than the diameter of the first guide needle hole 11, so that the preset guide needle can pass smoothly, thereby facilitating the installation of the main nail 1.

[0023] like Figure 5 As shown, the axis of the first guide needle hole 11 / the second guide needle hole 25 intersects with the center line of the oblique hole 23 to form an obtuse angle α, and the angle value of the angle α is engraved on the flange 22, which is equivalent to the angle value of the patient's neck-shaft angle.

[0024] The average neck-shaft angle of men is 132°, and the average neck-shaft angle of women is 127°. In this embodiment, the guide sleeve 2 assembly includes three types of guide sleeves 2 with angles α of 125°, 130° and 135°, but is not limited to these three angles. According to specific circumstances, guide sleeves 2 with multiple different angles can be set in the guide sleeve 2 assembly. In this embodiment, the angle between the center line of the directional hole 12 and the axis of the first guide needle hole 11 is 120°-130°, so as to facilitate the processing of inclined holes 23 with different inclination angles inside the guide sleeve 2.

[0025] like Figure 6 As shown, the tension screw 3 includes a threaded end 31 and a mating end 32. The threaded end 31 is locked in the femoral head, and the mating end 32 is inserted into the oblique hole 23 of the guide sleeve 2. The threaded end 31 is designed as a tapered thread, that is, the thread outer diameter of the threaded end 31 is consistent, and the thread bottom diameter gradually increases from the left end to the right end to achieve intraoperative pressurization. The mating end 32 is a bare rod structure, and an anti-rotation groove 33 is provided on the side of the mating end 32.

[0026] like Figure 7 As shown, the anti-rotation nail 7 includes a nut 71 and a polished rod 72. The nut 71 is threadedly connected in the main nail 1 and extends longitudinally along the main nail 1. In this embodiment, the nut 71 and the polished rod 72 are integrally formed.

[0027] Figure 8 The figure shows the schematic diagram of the installation of the tension screw 3 and the guide sleeve 2. When the tension screw 3 is inserted into the guide sleeve 2, the anti-rotation groove 33 is connected with the second guide needle hole 25. Figure 2 The lower end of the light rod 72 of the anti-rotation screw 7 can extend into the anti-rotation groove 33 along the second guide pin hole 25, which can effectively prevent the lag screw 3 from rotating in the circumferential direction. In particular, the anti-rotation groove 33 extends along the length direction of the lag screw 3, providing a certain adjustment space for the implantation depth of the lag screw 3.

[0028] The implantation process of the intramedullary nail in this embodiment is as follows: before the operation, a guide sleeve 2 corresponding to the neck-shaft angle is matched according to clinical needs, installed in the directional hole 12 of the main nail 1, and fixedly assembled to the main nail 1 with a fixing nail 5; the main nail 1 is implanted into the femoral medullary cavity through a preset guide needle, and then the tension screw 3 is implanted into the patient's body through the oblique hole 23 in the guide sleeve 2; the anti-rotation nail 7 is screwed into the main nail 1, and its lower end extends into the anti-rotation groove 33, intersecting with the tension screw 3 to achieve the anti-rotation function, and the locking nail 6 is implanted in the locking hole 14 at the distal end of the main nail 1, and finally the tail cap 4 is assembled on the top of the main nail 1.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An angle-adjustable femoral intramedullary nail, characterized in that: include: A main nail (1) is used for implantation in the longitudinal medullary cavity of a femur, wherein the main nail (1) is provided with an oblique directional hole (12); A guide sleeve (2) assembly, comprising a plurality of guide sleeves (2), wherein the guide sleeves (2) can be inserted into and fixed in the directional hole (12), wherein an oblique hole (23) is provided in the guide sleeve (2), and when different guide sleeves (2) are fixed in the directional hole (12), the central line of the oblique hole (23) has different angles with the longitudinal direction of the main nail (1); A tension screw (3) is inserted into the inclined hole (23) of the guide sleeve (2), and the center line of the tension screw (3) coincides with the axis line of the guide sleeve (2).

2. The angle-adjustable femoral intramedullary nail according to claim 1, characterized in that: The guide sleeve (2) comprises a tubular body (21) and a flange (22), wherein the flange (22) is arranged at one end of the tubular body (21), the tubular body (21) is inserted into the main nail (1), the flange (22) is attached to the outer surface of the main nail (1), a screw hole (24) is arranged on the flange (22), and the flange (22) is locked and fixed on the main nail (1) by a fixing nail (5) inserted into the screw hole (24).

3. The angle-adjustable femoral intramedullary nail according to claim 2, characterized in that: The tubular body (21) and the flange (22) are integrally formed.

4. The angle-adjustable femoral intramedullary nail according to claim 2, characterized in that: The outer edge of the directional hole (12) is provided with a groove (13), and when the flange (22) is embedded in the groove (13), the outer surface of the flange (22) does not exceed the surface around the groove (13).

5. The angle-adjustable femoral intramedullary nail according to claim 2, characterized in that: The flange (22) is engraved with the angle value of the angle between the center line of the inclined hole (23) and the longitudinal direction of the main nail (1).

6. The angle-adjustable femoral intramedullary nail according to claim 2, characterized in that: A first guide needle hole (11) is provided at the longitudinal center of the main nail (1), and a second guide needle hole (25) is provided on the tubular body (21); when the guide sleeve (2) is inserted into the oblique hole (23), the center line of the first guide needle hole (11) coincides with the center line of the second guide needle hole (25), and the diameter of the first guide needle hole (11) is less than or equal to the diameter of the second guide needle hole (25).

7. The angle-adjustable femoral intramedullary nail according to claim 1, characterized in that: An anti-rotation groove (33) is provided on the side of the tension screw (3), and an anti-rotation nail (7) is provided on the main nail (1), and the anti-rotation nail (7) can extend into the anti-rotation groove (33).

8. The angle-adjustable femoral intramedullary nail according to claim 7, characterized in that: The anti-rotation nail (7) comprises a nut (71) and a polished rod (72); the nut (71) is threadedly connected inside the main nail (1) and extends longitudinally along the main nail (1).

9. The angle-adjustable femoral intramedullary nail according to claim 7, characterized in that: The anti-rotation groove (33) extends in a long strip shape along the length direction of the tension screw (3).

10. The angle-adjustable femoral intramedullary nail according to claim 1, characterized in that: The main nail (1) comprises a proximal end, a middle section and a distal end. The proximal end of the main nail (1) is detachably mounted with a tail cap (4). The distal end of the main nail (1) is radially provided with a locking hole (14), and a locking nail (6) is detachably mounted in the locking hole (14).

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