Main nail for intramedullary nail system and intramedullary nail system

Abstract

The present invention relates to a main nail of an intramedullary nail system, which is particularly suitable for fixing lesser trochanter fractures and is also suitable for fixing common intertrochanteric fractures. A main nail of an intramedullary nail system, characterized in that it has an intramedullary nail main nail, the center of the intramedullary nail main nail is a through hole, and there are at least one hole on the proximal and distal side walls of the intramedullary nail main nail for accommodating a tension screw, a compression screw or a fixing locking nail; the proximal end of the intramedullary nail main nail is provided with an oblique overlapping hole, and the overlapping hole is characterized in that it is larger at the top and smaller at the bottom; an oblique arc groove is provided on the outer side wall of the proximal end of the intramedullary nail main nail along the lesser trochanter direction, the depth of the arc groove does not exceed its radius, and the bottom plane where the arc groove is located does not interfere with the outer contour surface of the upper hole in the overlapping hole; the proximal end of the intramedullary nail main nail has at least one proximal transverse locking nail hole located below the overlapping hole; and the distal end of the intramedullary nail main nail is provided with at least one distal end locking nail hole.

Description

Technical Field

[0001] The present invention relates to a main nail for an intramedullary nail system, and is particularly suitable for the main nail of an intramedullary nail system for fixing a lesser trochanteric fracture. In addition, the present invention also relates to an intramedullary nail system using the main nail. The main nail and intramedullary nail system are also suitable for fixing an intertrochanteric fracture of the femur or a femoral shaft fracture. Background Art

[0002] For patients with intertrochanteric fractures, if they also have lesser trochanteric fractures, it is necessary to reconstruct the femoral force line and fix the fractured part of the lesser trochanter during surgery. For femoral nails currently on the market, the locking screw hole in the lesser trochanter direction and the lag screw hole in the femoral head direction all pass through the center plane of the main nail. In the extended part of the lag screw along the femoral neck direction, the two holes interfere with each other in space, which makes it impossible to use the lag screw along the femoral neck direction and the screw along the lesser trochanter direction at the same time during surgery. Only one of the two can be selected. When facing patients with intertrochanteric fractures and fractures in the lesser trochanteric area, doctors give priority to using lag screws along the femoral head direction, and then use Kirschner's needles to assist in fixation of the lesser trochanteric fracture, reduce the freedom of fracture fragments, and restore the cortical bone support of the medial wall of the femur. Due to the limitations of the design of the intramedullary nail prosthesis, such fractures in the lesser trochanter area have not been professionally and effectively fixed. The potential risk is insufficient support for the medial wall, which increases the risk of secondary fractures after surgery. At the same time, if the fractured lesser trochanter is fixed completely from the space outside the main nail during surgery, the space occupied by the main nail in the medullary cavity needs to be completely avoided when the screw is implanted, which causes great damage to the patient's unilateral femur and is prone to iatrogenic fractures. Especially for patients with a small proximal femoral diameter, there is a lack of sufficient bone mass on one side of the femur to provide screw fixation. Summary of the invention

[0003] The purpose of the present invention is to provide a main nail for an intramedullary nail system in view of the shortcomings of the above intramedullary nail. In particular, for patients with intertrochanteric fractures and lesser trochanteric fractures, the femoral intramedullary nail designed according to this scheme can not only complete the reconstruction of the femoral force line, but also provide fixation of the lesser trochanteric fracture part. At the same time, the intramedullary nail designed according to the scheme of the present invention is also suitable for the fixation of intertrochanteric fractures or femoral shaft fractures.

[0004] The main nail used in the intramedullary nail system includes a main nail body, an overlapping hole and an arcuate groove. The main nail body has a proximal end and a distal end, and has an axial central through hole. The overlapping hole is arranged at the proximal end, and radially obliquely penetrates the main nail body. The side of the overlapping hole close to the proximal end is larger than the side close to the distal end, and is used to accommodate a tension screw and a compression screw respectively. The arcuate groove is arranged on the outer wall of the proximal end along the direction of the lesser trochanter, and is used to accommodate a trochanter fixing locking nail. The axis of the overlapping hole and the axis of the arcuate groove are not in the same plane, and the overlapping hole is arranged to avoid the arcuate groove.

[0005] According to one aspect of the main nail for an intramedullary nail system of the present invention, the depth of the arcuate groove is smaller than the radius of the trochanter fixation screw.

[0006] According to another aspect of the main nail for the intramedullary nail system of the present invention, the main nail body has at least one proximal transverse locking nail hole, and the proximal transverse locking nail hole is located on a side of the overlapping hole close to the distal end.

[0007] According to another aspect of the main nail for the intramedullary nail system of the present invention, the diameter of the proximal portion is greater than the diameter of the distal portion, and the angle between the axis of the proximal portion and the axis of the distal portion is 0 to 8 degrees.

[0008] According to another aspect of the main nail for an intramedullary nail system of the present invention, the angle between the axis of the overlapping hole (12) and the axis of the proximal portion is 120 to 140 degrees.

[0009] According to another aspect of the main nail for the intramedullary nail system of the present invention, the arc groove is arranged to avoid the thin-walled area around the overlapping hole and is located on the side of the overlapping hole close to the proximal end. The cutting area of ​​the arc groove at the proximal end of the main nail avoids the thin-walled area formed by the overlapping hole at the proximal end of the main nail. The arc groove is preferably located closer to the tail end of the main nail, which is safer in clinical practice, ensuring that the fatigue strength of the main nail of the intramedullary nail meets clinical requirements.

[0010] According to another aspect of the main nail for the intramedullary nail system of the present invention, the main nail has two transverse locking nail holes at the proximal end. One of the two transverse locking nail holes at the proximal end is a long slot hole, and the other is a circular hole. The long slot hole is closer to the overlapping hole than the circular hole.

[0011] According to another aspect of the main nail for the intramedullary nail system of the present invention, the main nail has three distal end locking nail holes. One of the distal end transverse locking nail holes is a long slot hole, and the other two are circular holes. The two circular holes are in the same direction. The angle between the axis of the long slot hole and the axis of the circular hole is 10 to 25 degrees.

[0012] According to another aspect of the main nail for the intramedullary nail system of the present invention, the farthest circular hole in the locking nail holes of the distal end portion is a threaded hole, and a convex ridge is provided in the long slot hole.

[0013] The present invention also aims to provide an intramedullary nail system using the above-mentioned main nail to address the shortcomings of the above-mentioned intramedullary nail. The intramedullary nail system includes the above-mentioned main nail, a lag screw and a tuberosity fixing locking nail. The lag screw can be arranged on one side of the overlapping hole close to the proximal end, and the tuberosity fixing locking nail can be arranged in the arc-shaped groove.

[0014] According to one aspect of the intramedullary nail system of the present invention, a compression screw is further included. The compression screw can be disposed on one side of the overlapping hole close to the distal end.

[0015] According to another aspect of the intramedullary nail system of the present invention, it further comprises at least one fixing screw, wherein the fixing screw is disposed in the transverse locking screw hole of the proximal portion.

[0016] According to another aspect of the intramedullary nail system of the present invention, the system further comprises at least one fixing screw, wherein the fixing screw is disposed in the transverse locking screw hole of the distal end portion.

[0017] The main nail used for the intramedullary nail system and the intramedullary nail system of the present invention have reasonable design and compact structure, and are particularly suitable for patients with intertrochanteric fractures and concomitant lesser trochanteric fractures. The femoral intramedullary nail designed according to this scheme can not only complete the reconstruction of the femoral force line, but also provide fixation of the lesser trochanteric fracture part.

[0018] Meanwhile, the intramedullary nail designed in the scheme of the present invention is also suitable for fixation of intertrochanteric fractures or femoral shaft fractures. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings:

[0020] Figure 1 It is a schematic diagram of the main nail structure of the intramedullary nail system of the present invention;

[0021] Figure 2 This is a schematic diagram of the main nail in the intramedullary nail system of the present invention. Figure 1 ;

[0022] Figure 3 This is a schematic diagram of the main nail in the intramedullary nail system of the present invention. Figure 2 ;

[0023] Figure 4 This is a schematic diagram of the main nail in the intramedullary nail system of the present invention. Figure 3 ;

[0024] Figure 5 This is a schematic diagram of the main nail in the intramedullary nail system of the present invention. Figure 4 .

[0025] In the figure: 1. Main nail, 2. Lag screw, 3. Compression screw, 6. Fixation screw, 7. Tuberosity fixation screw

[0026] 11. main nail body, 12. overlapping holes, 13. central through hole, 15. proximal end nail locking hole, 16. arc-shaped groove, 17. distal end nail locking hole;

[0027] Among them, 121 is an upper hole, 122 is a lower hole; 151 is a proximal long slot hole, 152 is a proximal circular hole;

[0028] 171. Distal circular hole, 172. Distal long slot hole, 172. Distal circular threaded hole. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings. The described implementation is a part of the implementation of the invention, rather than all the implementations. Based on the implementation of the present invention, all other implementations obtained by ordinary technicians in this field without making creative work are within the protection scope of the present invention.

[0030] See attached Figure 1-4 A main nail of an intramedullary nail system includes a main nail 1. The center of the main nail 1 is a through hole 13. The outer contour of the main nail 1 is thicker and straight at the proximal end and thinner and arc-shaped at the distal end. The proximal and distal axes of the main nail 1 have an angle of 0-8°. The proximal and distal ends of the main nail 1 have a smooth transition, and there are at least one hole on the proximal and distal side walls of the intramedullary nail for accommodating a tension screw 2, a compression screw 3 or a fixing locking nail 6.

[0031] An oblique overlapping hole 12 is provided at the proximal end of the main nail 1. The side of the overlapping hole 12 close to the proximal end is larger than the side close to the distal end (i.e., the so-called "larger at the top and smaller at the bottom"). The overlapping hole 12 is composed of an upper hole 121 and a lower hole 122. The angle between the axis of the overlapping hole 12 and the proximal axis of the main nail of the intramedullary nail is 120 to 140 degrees. The tension screw 2 can be installed in the upper hole 121 of the overlapping hole 12, and the compression screw 3 can be installed in the lower hole 122.

[0032] An oblique arc groove 16 is provided on the outer side wall of the proximal end of the main nail 1 along the direction of the lesser trochanter. The bottom plane of the arc groove 16 does not interfere with the outer contour surface of the upper hole 121 (large hole) above the overlapping hole 12 in the space of the proximal end of the femur. The cutting area of ​​the arc groove 16 at the proximal end of the main nail avoids the thin-walled area formed by the overlapping hole 12 at the proximal end of the main nail. The position of the arc groove 16 is preferably closer to the tail end of the main nail of the intramedullary nail. This area is safer in clinical practice, ensuring that the fatigue strength of the main nail 1 of the intramedullary nail meets clinical needs.

[0033] The proximal end of the main nail 1 is provided with at least one proximal transverse nail locking hole (transverse hole) 15 below the overlapping hole 12. The proximal transverse nail locking hole 15 is provided with a long slot hole 151 at the top and a circular hole 152 at the bottom.

[0034] The distal end of the main nail 1 is designed with no less than one distal locking hole 17, and preferably three distal locking holes 17 are provided, wherein two distal locking holes 171 and 173 are in the same direction, and the other distal locking hole 172 has an angle of 10-25° with the axes of the other two distal locking holes, wherein the distalmost locking hole 173 is preferably designed as a circular threaded hole, and the distal locking hole 172 is preferably designed as a long slotted hole with a convex ridge.

[0035] A threaded assembly is pre-installed in the central through hole 13 at the proximal end of the main nail 1, which is used to switch the positioning relationship between the tension screw 2 and the intramedullary nail main nail 1, and stabilize the two states of locking and unlocking. In the unlocked state, the tension screw 2 can slide along its axis in the main nail 1.

[0036] The proximal tail of the main nail 1 can be installed with a tail cap in the central through hole.

[0037] Embodiment 1: Figure 2 A schematic diagram of the main nail usage status of an intramedullary nail system Figure 1 The main nail of the intramedullary nail system has a main nail 1, a lag screw 2, a compression screw 3 and at least one fixing locking nail 6, wherein the lag screw 2 and the compression screw 3 are installed in the overlapping hole 12 at the proximal end of the main nail 1. The lag screw 2 and the compression screw 3 are installed obliquely from bottom to top to a suitable depth. At this time, driving the compression screw 3 can drive the lag screw 2 to retreat smoothly along its axis, generating a compression effect at the fracture end.

[0038] In a further embodiment, when the lesser trochanter is fractured, a trochanter fixation locking nail 7 is inserted into the arc groove 16 at the proximal end of the main nail 1 from the outside to the inside, toward the lesser trochanter, so as to fix the free fracture fragment in the lesser trochanter.

[0039] In a further embodiment, at least one fixing locking nail 6 is inserted into the locking nail hole 17 at the distal end of the main nail 1 to complete the fixation of the main nail 1 in the patient's medullary cavity. Figure 2 As shown in the figure, when there are three distal fixing locking screws 6, two of them are in the same direction, and the middle one and the two fixing locking screws in the same direction above and below it have an angle of 10-25° on the axis, forming distal interlocking, thereby improving the stability of the main screw 1 in the medullary cavity.

[0040] Embodiment 2: Figure 3 A schematic diagram of the main nail usage status of an intramedullary nail system Figure 2 A main nail of an intramedullary nail system comprises a main nail 1 and a fixing locking nail 6.

[0041] In a further embodiment, preferably, at least one fixing locking nail 6 is installed in the locking nail hole 17 at the distal end of the main nail 1 to complete the fixation of the main nail 1 of the intramedullary nail at the distal end of the patient's medullary cavity. Figure 3As shown in the figure, when there are three distal fixing locking screws 6, two of them are in the same direction, and the middle one and the two fixing locking screws 6 in the same direction above and below it have an angle of 10-25° on the axis, forming distal interlocking, thereby improving the stability of the main intramedullary nail 1 in the medullary cavity.

[0042] In a further embodiment, two fixing locking nails 6 are installed in the locking nail hole 15 at the proximal end of the intramedullary nail, and the installation order is to first install the fixing locking nail 6 at the upper middle of the proximal transverse locking nail hole 15. The fixing locking nail 6 is preferably close to one side of the upper edge of the long slot hole 151, and after the fracture end is pressurized and closed by the instrument, the fixing locking nail 6 at the lower middle of the proximal locking nail hole 15 is installed.

[0043] In a further embodiment, when the lesser trochanter is fractured, a trochanter fixation locking nail 7 is inserted from the outside to the inside toward the lesser trochanter in the arc groove 16 at the proximal end of the intramedullary nail main nail 1, so as to fix the free fracture fragment in the lesser trochanter.

[0044] Embodiment 3: Figure 4 A schematic diagram of the main nail usage status of an intramedullary nail system Figure 3 A main nail of an intramedullary nail system comprises a main nail 1, a lag screw 2, a compression screw 3 and a fixing locking nail 6. The lag screw 2 and the compression screw 3 are installed in overlapping holes 12 at the proximal end of the main nail 1, and the lag screw 2 and the compression screw 3 are installed obliquely from bottom to top to the expected depth.

[0045] In a further embodiment, preferably, at least one fixing locking nail 6 is installed in the locking nail hole 17 at the distal end of the main nail 1 to complete the fixation of the main nail 1 at the distal end of the patient's medullary cavity. Figure 4 As shown in the figure, when there are three distal fixing locking screws 6, two of them are in the same direction, and the middle one and the two fixing locking screws in the same direction above and below it have an angle of 10-25° on the axis, forming distal interlocking, thereby improving the stability of the main intramedullary nail 1 in the medullary cavity.

[0046] Embodiment 4: Figure 5 A schematic diagram of the main nail usage status of an intramedullary nail system Figure 4 A main nail of an intramedullary nail system comprises a main nail 1 and a fixing locking nail 6, and is suitable for fixing femoral shaft fractures.

[0047] In a further embodiment, preferably, at least one fixing locking nail 6 is installed in the locking nail hole 17 at the distal end of the main nail 1 to complete the fixing of the main nail 1 at the distal end of the patient's medullary cavity. Figure 5 As shown in the figure, when there are three distal fixing locking screws 6, two of them are in the same direction, and the middle one and the two fixing locking screws in the same direction above and below it have an angle of 10-25° on the axis, forming distal interlocking, thereby improving the stability of the main intramedullary nail 1 in the medullary cavity.

[0048] In a further embodiment, two fixed locking nails 6 are installed in the proximal locking nail hole 15 of the intramedullary nail. The installation order is to first install the upper fixed locking nail 6 in the proximal transverse locking nail hole 15. The fixed locking nail 6 is preferably close to the upper edge of the long slot hole 151. After the fracture end is pressurized and closed by an instrument, the lower fixed locking nail 6 in the proximal locking nail hole 15 is installed.

Claims

1. A main nail for an intramedullary nail system, characterized in that: include: A main nail body (11) having a proximal end and a distal end, and having an axial central through hole (13); an overlapping hole (12) arranged at the proximal end and obliquely passing through the main nail body (11) in the radial direction, wherein a side (121) of the overlapping hole (12) close to the proximal end is larger than a side (122) close to the distal end, and is used to accommodate a tension screw (2) and a pressure screw (3), respectively; and an arcuate groove (16) arranged on the outer wall of the proximal end along the direction of the lesser trochanter, and is used to accommodate a trochanter fixing locking nail (7); wherein the axis of the overlapping hole (12) and the axis of the arcuate groove (16) are not in the same plane, and the overlapping hole (12) is arranged to avoid the arcuate groove (16); The depth of the arc-shaped groove (16) is smaller than the radius of the trochanter fixing nail (7); The main nail body (11) has at least one proximal transverse nail locking hole, and the proximal transverse nail locking hole is located on a side of the overlapping hole (12) close to the distal end; The diameter of the proximal portion is greater than the diameter of the distal portion, and the angle between the axis of the proximal portion and the axis of the distal portion is 0 to 8 degrees; The angle between the axis of the overlapping hole (12) and the axis of the proximal end portion is 120 to 140 degrees; The arc-shaped groove (16) is arranged to avoid the thin-walled area around the overlapping hole (12) and is located on a side of the overlapping hole (12) close to the proximal end; There are two proximal transverse locking nail holes, one of which is a proximal long slot hole and the other is a proximal circular hole, and the proximal long slot hole is closer to the overlapping hole (12) than the proximal circular hole; There are three distal transverse locking nail holes, one of which is a distal long slot hole, and the other two are distal circular holes. The two distal circular holes have the same direction, and the angle between the axis of the distal long slot hole and the axis of the distal circular hole is 10 to 25 degrees.

2. The main nail for the intramedullary nail system according to claim 1, wherein the farthest distal circular hole in the distal end transverse locking nail holes is a threaded hole, and a convex ridge is provided in the distal long slot hole.

3. An intramedullary nail system, characterized in that: It comprises a main nail (1) as claimed in any of the above claims, a tension screw (2) and a trochanter fixing locking nail (7), wherein the tension screw (2) can be arranged on a side (121) close to the proximal end of the overlapping hole (12), and the trochanter fixing locking nail (7) can be arranged in the arc groove (16).

4. The intramedullary nail system according to claim 3, further comprising a compression screw (3), wherein the compression screw (3) can be arranged on a side (122) close to the distal end of the overlapping hole (12).

5. The intramedullary nail system according to claim 4, further comprising at least one fixing screw (6), wherein the fixing screw (6) is disposed in the transverse locking screw hole at the proximal portion.

6. The intramedullary nail system according to claim 4, further comprising at least one fixing screw (6), wherein the fixing screw (6) is disposed in the transverse locking screw hole at the distal portion.

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