Femoral neck angle stable type double-arm single-head sliding pressurization tension lock nail

Abstract

The invention relates to a femoral neck angle stable type double-arm single-head sliding pressurization tension lock pin, and belongs to the technical field of medical instruments. For treatment of femoral neck fractures, an internal fixing device which has angle stability and can continuously pressurize is lacked, an intramedullary main nail and two sets of double-arm single-head combined lock nails are arranged, the intramedullary main nail is arranged in the femoral tuberosity part, and the two sets of double-arm single-head combined lock nails and the intramedullary main nail are obliquely interlocked and connected to form an angle-stable and easy-sliding structure. The double-arm single-head combined lock pin comprises pressurizing arms and a track inward-extending supporting arm, the femoral neck fracture is pressurized and fixed through the two pressurizing arms, the track inward-extending supporting arm abuts against and supports the lower portion of the middle section of each pressurizing arm, an arc-shaped sliding supporting table and a supporting inclined face are arranged at the top end of each track inward-extending supporting arm, and the pressurizing arms are held; meanwhile, the fulcrum, relative to the pressurizing arm, of the main intramedullary nail moves inwards, a sliding rail is prolonged, the vertical swing amplitude of the pressurizing arm is reduced, the sliding retreating capacity of the pressurizing arm is improved, and the unlocking effect is generated.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a femoral neck angle-stabilized double-arm single-head sliding compression tension locking nail. Background Art

[0002] Femoral neck fractures are prone to nonunion or femoral head necrosis because most of the blood supply to the femoral head is destroyed. In addition, the effective fixation arm of the femoral head is very short, and the gravity-bearing line deviates greatly from the anatomical longitudinal axis of the femoral shaft, the shear stress increases, making it difficult to effectively fix. The mainstream fixation method in China uses three hollow compression screws for fixation. The hollow screws have good initial compression and subsequent sliding compression, but they have no angular stability. The actual angular stability can only be achieved by relying on the bone support force of the interlocking fracture interface. If osteoporosis, fracture comminution, or a large Pauwells angle is encountered, it is easy to fail; at the same time, the screw placement requires close contact with the bone cortex around the femoral neck, which is difficult to operate without navigation. Reconstruction top fixation has angular stability, but the sliding track of the locking screw inside the main screw is short, which is easy to produce a locking effect, and the sliding retreat force is greatly reduced. In addition, the asynchronous sliding of the two femoral neck locking screws causes a "Z" effect, which is prone to failure (refer to Fig.15 The United States designed the FNS fixation system, which has both sliding compression and angular stability. However, the head pin is too thick, the bone loss in the head is too much, the blood supply is greatly damaged, the necrosis rate is high, the absorption and shortening are more, and the single-pin fixation has poor anti-rotation ability.

[0003] In view of this, it is particularly important to combine the biomechanical properties of femoral neck fractures, develop and design new femoral neck fracture internal fixation devices to solve the problem of femoral neck fractures. Summary of the invention

[0004] In view of the deficiencies in the above-mentioned prior art, the present invention aims to provide a femoral neck angle-stabilized double-arm single-head sliding compression tension locking nail, which is provided with two groups of double-arm single-head combination locking nails parallel to each other and obliquely connected to the intramedullary main nail, each group of double-arm single-head combination locking nails includes a compression arm and a track inner extension support arm, and the femoral neck fracture is compressed and fixed by two compression arms. In the early stage of healing, the tension fixation and compression of the first operation are relied on, and in the later stage, the sliding compression is relied on. The two track inner extension support arms are used to respectively realize the support and stability of the corresponding compression arms, effectively preventing the compression arm from swinging horizontally. At the same time, the track inner extension support arm moves the fulcrum of the intramedullary main nail to the compression arm inward and extends the sliding track, which not only reduces the vertical swing amplitude of the compression arm, but also produces an unlocking effect, and increases the sliding backward ability of the compression arm. The "Z" effect is effectively eliminated, thereby better solving the problems existing in the background technology.

[0005] The present invention achieves the above technical objectives through the following technical solutions: The femoral neck angle-stabilized double-arm single-head sliding compression tension locking nail comprises an intramedullary main nail and two groups of double-arm single-head combined locking nails interlocked with the intramedullary main nail. The intramedullary main nail is arranged in the trochanteric part of the femur. The two groups of double-arm single-head combined locking nails are parallel to each other and both groups of double-arm single-head combined locking nails are obliquely connected to the intramedullary main nail. The femoral neck fracture is fixed by the two groups of double-arm single-head combined locking nails.

[0006] As a further preferred solution of the above technical solution: each group of double-arm single-head combination locking nails includes a pressure arm and an inward-extending track support arm, two parallel pressure arms pass through the two first nail holes on the intramedullary main nail, two parallel inward-extending track support arms pass through the two second nail holes on the intramedullary main nail, and the top end of each inward-extending track support arm abuts against the bottom of the adjacent pressure arm.

[0007] In order to achieve the above purpose, further, the axial angle α1 between the pressure arm and the intramedullary main nail is 45°, and the axial angle α2 between the track inner extension support arm and the intramedullary main nail is 42.5°.

[0008] A further preferred solution is that the diameter of the pressure arm is 6.5-6.9 mm, and the tail end thereof is provided with a self-tapping thread with a length of 15-20 mm.

[0009] A further preferred solution is that the distance between the two pressurizing arms is 1.5 to 2 times the diameter of the pressurizing arm itself.

[0010] Based on the above technical solution, further, the diameter of the track inner extension support arm is 6.5 mm, and the track inner extension support arm is provided with an external thread, and the track inner extension support arm is connected to the second nail hole through the external thread.

[0011] A further preferred solution is that a support platform is provided at the top end of the inner extension support arm of the track, and the pressure arm is supported by the support platform.

[0012] Preferably, the support platform includes an arc-shaped sliding support platform and a supporting slope. The arc-shaped sliding support platform is arranged at the top end of the inwardly extending support arm of the track. The supporting slope is located between the external thread and the arc-shaped sliding support platform. The depth of the supporting slope gradually increases from the middle section of the inwardly extending support arm of the track to its top end. The end of the supporting slope is connected to the arc-shaped sliding support platform.

[0013] More preferably, the length of the arc-shaped sliding support platform is 5 mm, the depth of the recessed arc-shaped sliding support platform is 2.5 mm, the upper end of the arc-shaped sliding support platform is an arc-shaped concave surface, and the depth of the arc-shaped concave surface gradually deepens from the tail end of the inner support arm of the track to the tail end of the inner support arm of the track.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention sets two groups of double-arm single-head combination locking nails, which include a pressure arm and an inner extension support arm of the track, wherein the two pressure arms are parallel to each other and the distance between them is 1.5 to 2 times of the diameter of the pressure arm. The two pressure arms are used to pressurize and fix the femoral neck fracture, which can not only make the fracture continue to slide and pressurize, but also maintain the stability of the metal support angle. At the same time, the inner extension support arm of the track moves the fulcrum of the main nail relative to the pressure arm inward and extends the sliding track, which not only reduces the vertical swing amplitude of the pressure arm, but also produces an unlocking effect and increases the sliding backward ability of the pressure arm. The "Z" effect is effectively eliminated, thereby better solving the problems existing in the background technology part.

[0015] 2. The present invention sets a support part at the top end of the track inner extension support arm, and the support part includes an arc-shaped sliding support platform and a supporting inclined surface. The cylindrical side surface of the track inner extension support arm that originally contacts the pressure arm is designed to be a combination of an arc-shaped concave surface and an inclined plane. After the track inner extension support arm is rotated into place, it is supported on the side wall of the pressure arm in a semi-wrapped manner by the arc-shaped concave surface, thereby increasing the lateral restriction between the arc-shaped sliding support platform and the pressure arm, preventing the pressure arm and the track inner extension support arm from relative displacement, and at the same time utilizing the supporting inclined surface to increase the contact area with the pressure arm, thereby further improving the stability of the track inner extension support arm in supporting the pressure arm.

[0016] 3. The present invention has a simple structure, is easy to operate, and has a good fixation effect on the femoral neck fracture end. In actual use, it can be processed into various specifications according to clinical needs to meet the diverse needs of different patients' physical characteristics and improve its universal clinical applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0018] Figure 1 It is a schematic diagram of the overall structure of the femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail of the present invention; Figure 2 For the present invention Figure 1 An enlarged schematic diagram of the structure of the double-arm single-head combination locking nail; Figure 3 It is a schematic diagram of the partial structure of the double-arm single-head combination locking nail of the present invention; Figure 4 It is a partial structural perspective view of the double-arm single-head combination locking nail of the present invention; Figure 5 is a cross-sectional view of the intramedullary main nail of the present invention; Figure 6 It is a structural schematic diagram of the pressure arm of the present invention; Figure 7It is a schematic structural diagram of the track inner extension support arm of the present invention; Figure 8 It is a side view of the track inner extension support arm of the present invention; Fig. 9 It is a partially enlarged schematic diagram of the track inner extension support arm of the present invention; Fig.10 It is a front view of the shallower end of the arc-shaped sliding support platform of the present invention; Fig.11 It is a front view of the deeper concave end of the arc-shaped sliding support platform of the present invention; Fig.12 The state diagram of the overall structure of the present invention in clinical operation Fig.13 The real object of the track inner extension support arm of the present invention Figure 1 ; Fig.14 The real object of the track inner extension support arm of the present invention Figure 2 ; Fig.15 A physical diagram of the pressure arm at the upper end of the present invention; Fig.16 A physical diagram of the pressure arm at the lower end of the present invention; Fig.17 It is a physical diagram of the overall structure of the present invention; Fig.18 The prior art operation X-ray film diagram in the background technology of the present invention; In the figure: 1. Intramedullary main nail; 11. First nail hole; 12. Second nail hole; 2. Double-arm single-head combination locking nail; 21. Pressure arm; 211. Bone self-tapping thread; 22. Track inner extension support arm; 221. External thread; 222. Arc-shaped sliding support platform; 223. Support slope; 3. Hollow nail. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0020] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc., are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0021] Embodiment 1: Reference Figure 1-6 The present invention provides a femoral neck angle-stabilized double-arm single-head sliding compression tension locking nail, comprising an intramedullary main nail 1 and a double-arm single-head combined locking nail 2. The intramedullary main nail 1 is placed in the trochanter of the femur, and two groups of double-arm single-head combined locking nails 2 are provided. The two groups of double-arm single-head combined locking nails 2 are parallel to each other and are obliquely connected to the intramedullary main nail 1. The fracture site of the femoral neck is fixed by the two groups of double-arm single-head combined locking nails 2.

[0022] Specifically, a countersunk hexagonal groove is provided at the head end of the intramedullary main nail 1. The length of the intramedullary main nail 1 is 180 mm. It consists of a cylindrical structure at the upper end and a conical structure at the lower end. The cylindrical structure and the conical structure have a smooth transition and are integrally formed. The length of the cylindrical structure is 120 mm and the diameter is 13 mm. The length of the conical structure is 60 mm and the diameter of the end is 9-10 mm.

[0023] like Figure 5 As shown, the intramedullary main nail 1 has a first nail hole 11 and a second nail hole 12 in sequence from top to bottom. There are two first nail holes 11 and two second nail holes 12. The two first nail holes 11 are parallel to each other, the two second nail holes 12 are parallel to each other, and the two first nail holes 11 and the two second nail holes 12 are alternately distributed.

[0024] like Figure 2-4 As shown, each group of double-arm single-head combination locking nails 2 includes a pressure arm 21 (a sliding pressure tension locking nail located at the upper part) and a track inner extension support arm 22 (a non-sliding support locking nail located at the lower part), the track inner extension support arm 22 is located below the pressure arm 21, the pressure arm 21 is connected to the intramedullary main nail 1 through the first nail hole 11, and the pressure arm 21 crosses the fracture line to compress and fix the fracture, the intersection of the pressure arm 21 and the intramedullary main nail 1 is a sliding connection, and the nail can be withdrawn, the track inner extension support arm 22 is connected to the intramedullary main nail 1 through the second nail hole 12, and the track inner extension support arm 22 does not cross the fracture line, the intersection of the track inner extension support arm 22 and the intramedullary main nail 1 is threadedly connected, the nail cannot be withdrawn, and the top end of the track inner extension support arm 22 abuts against the bottom of the pressure arm 1, which has a supporting and limiting effect on the pressure arm 21.

[0025] In this embodiment, the tail of the pressure arm 21 is a cross screw, the diameter of the pressure arm 21 is 6.5-6.9 mm, and its length is 85~100 mm. A bone self-tapping thread 211 with a length of 15~20 mm is provided at the top of the pressure arm 21. The spacing between the two pressure arms 21 is 1.5~2 times the diameter of the pressure arm 21. After the pressure arm 21 is inserted into the first nail hole 11, the axial angle α1 formed with the intramedullary main nail 1 is 45°.

[0026] In this embodiment, a countersunk hexagonal groove is provided at the tail end of the track inner extension support arm 22. The diameter of the track inner extension support arm 22 is 6.5 mm, and its length is 5.3 mm and 6.3 mm. An external thread 221 is provided on the track inner extension support arm 22. The external thread 221 is opened near its tail end, and the length of the external thread 221 is 27.5 mm. The external thread 221 cooperates with the internal thread in the second nail hole 12, and the track inner extension support arm 22 is connected to the second nail hole 12 through the external thread 221. After the track inner extension support arm 22 is inserted into the second nail hole 12, the axial angle α2 formed with the intramedullary main nail 1 is 42.5°; the hexagonal groove of the track inner extension support arm 22 is set to facilitate the doctor to fine-tune the position of the track inner extension support arm 22 with a screwdriver to ensure the effective support of the track inner extension support arm 22 to the pressure arm 21.

[0027] Embodiment 2: On the basis of the above-mentioned first embodiment, in order to better prevent the pressure arm 21 from shifting and rotating in angle, the structure of the track inner extension support arm 22 is further designed as follows.

[0028] like Figure 7-11 As shown, a support portion is provided at the top end of the track inner extension support arm 22, and the support portion includes an arc-shaped sliding support platform 222 and a support inclined surface 223. The arc-shaped sliding support platform 222 and the support inclined surface 223 are formed by cutting on the track inner extension support arm 22, wherein: the arc-shaped sliding support platform 222 is provided at the top end of the track inner extension support arm 22, and the upper end of the arc-shaped sliding support platform 222 is an arc-shaped concave surface, and the depth of the arc-shaped concave surface gradually deepens from the tail end of the track inner extension support arm 22 to the tail end of the track inner extension support arm 22, that is, the cross-section of the arc-shaped sliding support platform 222 is a "crescent" shape that decreases successively (refer to Fig.10 , Fig.11 ), the supporting slope 223 is an inclined plane, the supporting slope 223 is located between the external thread 221 and the arc-shaped sliding support platform 222, the depth of the supporting slope 223 gradually increases from the middle section of the inner extension support arm 22 of the track to the top end, and the end of the supporting slope 223 extends to connect with the arc-shaped sliding support platform 222. At the same time, the end height of the supporting slope 223 does not exceed the lowest support point of the arc-shaped sliding support platform 222.

[0029] When the track inward extension support arm 22 is rotated into position, it is supported on the bottom side wall of the pressure arm 21 in a semi-wrapped manner through the arc-shaped concave surface, thereby increasing the contact between the arc-shaped sliding support platform 222 and the pressure arm 21, and can effectively prevent the pressure arm 21 and the track inward extension support arm 22 from relative displacement. At the same time, the support inclined surface 223 is used to further increase the contact area with the pressure arm 21, thereby improving the stability of the track inward extension support arm 22 in supporting the pressure arm 21.

[0030] In this embodiment, if Figure 8 , Figure 10-11 As shown, the length b of the arc-shaped sliding support platform 222 is 5 mm, and the recessed depth of the arc-shaped sliding support platform 222 extends from 2.5 mm close to the head end c1 of the track inner extension support arm 22 to 3 mm away from the head end c2 of the track inner extension support arm 22.

[0031] Embodiment three: The invention discloses a femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail, referring to Fig.12 , combined with the actual product picture that has been produced by the present invention and is about to be put into clinical use Figure 13-Figure 17 , in clinical practice: According to the clinical treatment plan, the patient underwent closed reduction and temporary fixation in the emergency (or sub-emergency) department; after anesthesia, the patient was placed on a traction bed for reduction. After the fracture was roughly reduced by anteroposterior and lateral fluoroscopy, three Kirschner wires with a diameter of 2.5 mm were inserted into the femoral neck for temporary fixation. At the same time, the ipsilateral tibial tuberosity bone was traction-immobilized with a traction weight of 6 kg. After traction for 7-9 days, a decisive surgical treatment was performed. Because closed immobilization can fully subside the original traumatic inflammation, it can greatly increase the fracture healing ability and greatly reduce (or even eliminate) the absorption / shortening phenomenon of the fracture end. After one week of traction, open reduction can also produce a secondary trauma healing response for those with poor surgical reduction, increase the fracture healing ability, and bone grafting can be used to increase the healing ability if necessary.

[0032] During the operation, the patient is placed on the traction bed again, and a 5-6 cm skin incision is made longitudinally above the trochanteric part of the femur to fully expose the top of the trochanteric part. First, a guide pin is inserted, and fluoroscopy is used to confirm that the guide pin is placed in the appropriate position in the medullary cavity. Then the proximal femoral medullary expansion is performed. Before medullary expansion, the Kirschner wire that hinders the medullary expansion is removed. In addition, a suitable position is selected to insert the Kirschner wire to maintain reduction. The main intramedullary nail 1 is inserted to a suitable depth, and 1-2 hollow nails with a diameter of 7.3 mm are inserted next to the main intramedullary nail 1 (mostly on the front side) as perpendicular to the fracture line as possible to fix it with pressure. After the fracture line disappears completely, two non-sliding support locking nails 22 are inserted, and finally two sliding compression tension locking nails 21 are inserted. Patients without anatomical reduction or with poor fracture prognosis are immediately opened, reduced and bone grafted to increase the fracture healing ability.

[0033] It should be noted that in clinical practice, reference Fig.12As shown in the figure, 1-2 7.3mm hollow screws are placed outside the intramedullary main screw for compression fixation, and the concept of reconstructing the nail angle stability is combined with the concept of hollow screw compression. It not only retains the advantages of thin nails and multiple nails of hollow screws, but also successfully transforms the "bone support angle stability" into "metal support angle stability", which can reduce bone absorption caused by micro-motion of the fracture ends (at the same time, delaying the operation to increase the growth capacity of the bone ends and further reduce bone end absorption), reduce the occurrence of nail withdrawal and shortening, and does not require strict wall fixation with simple hollow screws, reduces the difficulty of surgical fluoroscopic positioning, and facilitates the development of clinical work in primary hospitals.

[0034] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. Femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail, characterized in that: The invention comprises an intramedullary main nail (1), and two groups of double-arm single-head combined locking nails (2) connected to the intramedullary main nail (1). The intramedullary main nail (1) is placed in the trochanteric part of the femur, the two groups of double-arm single-head combined locking nails (2) are parallel to each other, and the two groups of double-arm single-head combined locking nails (2) are connected to the intramedullary main nail (1) at an angle, and the femoral neck fracture is fixed by the two groups of double-arm single-head combined locking nails (2).

2. The femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail according to claim 1, characterized in that: Each set of double-arm single-head combination locking nails (2) comprises a pressure arm (21) and a track inner extension support arm (22), wherein two parallel pressure arms (21) penetrate two first nail holes (11) on the intramedullary main nail (1), and two parallel track inner extension support arms (22) penetrate two second nail holes (12) on the intramedullary main nail (1), and the top end of each track inner extension support arm (22) abuts against the bottom of the adjacent pressure arm (21).

3. The femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail according to claim 2, characterized in that: An axial angle α1 between the pressure arm (21) and the intramedullary main nail (1) is 45°, and an axial angle α2 between the track inner extension support arm (22) and the intramedullary main nail (1) is 42.5°.

4. The femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail according to claim 3, characterized in that: The pressure arm (21) has a diameter of 6.5-6.9 mm and a self-tapping thread (211) with a length of 15-20 mm is provided at its top.

5. The femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail according to claim 4, characterized in that: The distance between the two pressure arms (21) is 1.5 to 2 times the diameter of the pressure arm (21).

6. The femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail according to claim 3, characterized in that: The track inner extension support arm (22) has a diameter of 6.5 mm and is provided with an external thread (221), through which the track inner extension support arm (22) is connected to the second nail hole (12).

7. The femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail according to claim 6, characterized in that: A support portion is provided at the top end of the track inner extension support arm (22), and the pressure arm (21) is supported by the support portion.

8. The femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail according to claim 7, characterized in that: The support portion comprises an arc-shaped sliding support platform (222) and a supporting inclined surface (223); the arc-shaped sliding support platform (222) is arranged at the top end of the track inner extension support arm (22); the supporting inclined surface (223) is located between the external thread (221) and the arc-shaped sliding support platform (222); the depth of the supporting inclined surface (223) gradually increases from the middle section of the track inner extension support arm (22) to the top end thereof; the end of the supporting inclined surface (223) is connected to the arc-shaped sliding support platform (222).

9. The femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail according to claim 8, characterized in that: The length of the arc-shaped sliding support platform (222) is 5 mm, and the recessed depth of the arc-shaped sliding support platform (222) is 2.5-3 mm.

10. The femoral neck angle stabilizing double-arm single-head sliding compression tension locking nail according to claim 9, characterized in that: The upper end of the arc-shaped sliding support platform (222) is an arc-shaped concave surface, and the depth of the arc-shaped concave surface gradually increases from the tail end of the track inner extension support arm (22) close to the tail end of the track inner extension support arm (22) to the tail end of the track inner extension support arm (22) away from the tail end.

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