Intramedullary fixing device for femur fractureTechnical Field
The invention belongs to the technical field of femoral neck fracture reduction fixing appliances, and particularly relates to an intramedullary fixing device for femoral fracture.
Background
Fracture of the femoral neck and tuberosity is a common frequently occurring occurrence of the elderly. When the screw and nail plate system is fixed on the fracture of the femoral neck or the intertrochanteric fracture, the traditional internal fixation method for the fracture of the femoral neck is quite a lot, and the fracture is difficult to operate and has a lot of complications, so that the joint replacement is often performed finally. The femur neck anatomical structure is special, the neck stem angle and the forward inclination angle exist on different planes, and the positions are deep and hidden, so that the positioning guide needle is difficult to correctly place. In clinic, when the internal fixation is used for treating fracture of femoral neck and femoral tuberosity, the guide needle is firstly put into the fracture for positioning. The main factor of the traditional fixing mode of the guide needle placement is the problem of infirm fixing usually based on the clinical experience of doctors.
On the other hand, the femoral neck includes an outer hard bone portion and an inner loose bone portion, as shown in fig. 15, which fills the entire bone cavity. The inner layer loose bone parts are large in size and small in density, the intramedullary nails are fixed on the outer layer hard bone parts and have fixing strength, but the fixing strength of the intramedullary nails fixed on the inner layer loose bone parts is insufficient, and most of the intramedullary nails are actually positioned on the inner layer loose bone parts. The outer diameter of the root and the tail end of the femur neck is larger than that of the neck, and partial intramedullary nail is exposed outside the neck, so that the problem of poor fixation of the intramedullary nail is caused.
In the prior art, a structure similar to an expansion wire is adopted, the inner wall of a bone cavity is supported in the bone cavity of a femur neck through expanding an expansion part, the bone cavity is actually supported on a loose bone part and compresses the loose bone part to a hard bone inner wall, and the bone pressing device through expansion has the following problems: the expansion surface is an arc surface, a loose bone part cannot be completely stripped to be in direct contact with the inner wall of a hard bone, so that the firmness degree is insufficient after compression, (2) sufficient constraint force of a femoral neck in the circumferential direction cannot be provided after expansion and compression, the femoral neck is likely to be misplaced due to rotation, (3) the expansion surface is large in damage to the loose bone part, when the inner end of the expansion surface is expanded, all the loose bone part in the cavity of the femoral neck is damaged, (4) the expansion part of the inner end of the expansion surface cannot be completely matched with the inner wall of the cavity of the femoral neck, sufficient anti-torsion force cannot be provided, the fracture reduction of a patient suffering from the femoral neck fracture is required to be maintained at the position in the lower limb, the point is embedded by an acetabulum and is not completely spherical, and the rotation of the body position brings large torsion force to an internal supporting part, so that the expansion part of the inner end is in point contact with the inner wall of the femoral neck, and the internal pressure firmness is poor. For example, the 'expansion fixing femoral head inner support body' provided by publication number CN 202146350U comprises a support main body and an inner expansion screw, the support main body is sleeved outside the inner expansion screw, the top of the support main body is arc-shaped, the support main body is provided with radial expansion wings, each expansion wing consists of a plurality of wings, expansion gaps are formed between each wing, the inner expansion screw is provided with an expansion section, the expansion section can expand the expansion wings after the inner expansion screw is placed into the support main body, and the support main body is in threaded connection with the inner expansion screw. And as another example, the femur tuberosity with publication number CN 2659365Y is fixed with a self-locking compound interlocking intramedullary nail. And other technical solutions applied to the inter-tuberosity cavity of the femur for support, approximately in the form of an expansion peg. The technique generally utilizes the expansion nail principle to implant the expansion nail into the inner cavity of the femur Long Buwei, the expansion degree of each expansion blade is limited, and is insufficient to form a large enough inner support body, in addition, the scheme needs to screw and advance inwards, the screw is easy to reach the limit support and prop against the end part of the femur inner cavity, and cannot advance continuously, so that the expansion direction of each expansion blade is in an abduction shape, the hanging relation cannot be formed on the femur bulge part inner cavity, and the expansion blades cannot go deep into fluffy bone to contact with the outer hard bone wall due to the existence of a large width, so that the problems of insufficient traction strength and insufficient rotation preventing capability of the expansion blades are possibly caused, and secondary damage accidents are possibly caused due to the fact that the fixing state is unstable.
Disclosure of Invention
Aiming at the defects and problems of various fixing modes of the existing femur neck, the invention provides a method for realizing that all blades are unfolded in the inner cavity between femur tuberosities to form a reverse hanging relation by screwing a small knob at the tail end, and the tightening nut is screwed to lock and fix, so that the fracture part of the femur neck can be effectively fixed from the inside, and enough torsion preventing force can be provided.
The invention solves the technical problem by adopting a femoral fracture intramedullary fixation device which mainly comprises an outer sleeve, a core bar, a blade set, a driving component and the like. Wherein the peripheral edge of the front end pipe orifice of the outer sleeve is uniformly distributed with a plurality of axial knife grooves, the outer circumferential wall near the pipe orifice is provided with an inward concave annular groove, the outer side of the rear end pipe orifice of the outer sleeve is provided with a thread section, the outer side of the thread section is provided with a tensioning nut, the core rod comprises a screw rod section, the rear end of the core rod is connected with a tail end small knob, the core rod is matched and sleeved in the outer sleeve, the whole core rod can be driven to rotate relative to the outer sleeve by rotating the tail end small knob, the blade group comprises a rigid ring and a plurality of blades, each blade comprises a shaft hole at the tail end and an arc-shaped cutter head at the head end, each blade is sleeved on the rigid ring through the shaft hole at the tail end of the blade, the blade can rotate freely relative to the rigid ring, the rigid ring is sleeved in the annular groove, each blade is positioned in the corresponding blade groove, the driving assembly comprises a movable sleeve which is connected to the outer side of the threaded section of the core rod in a threaded mode, protruding hinging seats are respectively arranged at the peripheral edge of the outer side of the movable sleeve, shaft holes are respectively formed in the hinging seats and are respectively hinged with push-pull rods through pin shafts, pin holes are further distributed in the inner sides of the middle parts of the blades, and the tail ends of the push-pull rods are respectively hinged in the corresponding pin holes through pin shafts.
Further, the driving assembly further comprises a fixed sleeve fixed at the front end of the outer sleeve, and the inner end of the core rod is sleeved on the fixed sleeve and can rotate freely.
And a sleeve head can be sleeved at the inner end of the mandrel, the sleeve head is matched and sleeved in the central hole of the fixed sleeve, the tail end of the mandrel, namely the sleeve head end part, is sleeved with a base plate, the base plate is fixed at the sleeve head end part through a penetrating wire, the penetrating wire spirally enters the central screw hole, and a small fit gap exists between the base plate and the fixed sleeve so that the base plate can rotate along with the sleeve head, namely the core rod.
In order to prevent the fixed sleeve from rotating relative to the outer sleeve, a combined screw hole and a locking wire can be arranged at the outer edge of the fixed sleeve and the inner edge of the pipe orifice of the outer sleeve.
A pair of blind holes are formed in the end face of the fixed sleeve, and the fixed sleeve is screwed and assembled by being clamped into the corresponding blind holes through a fork-shaped wrench.
The outer edge profile of the cutter head of the cutter blade protrudes outwards and is toothed, and the end part of the cutter head of the cutter blade can also be in a hook shape.
When the tightening nut is arranged on the outer side of the thread section, the gasket close to the curvature of the bone surface is sleeved.
4-8 axial knife grooves are formed in the front end of the outer sleeve, and blades with matched thickness are respectively arranged in each axial knife groove.
The intramedullary nail is implanted and fixed in the femoral bone cavity, the proximal end of the intramedullary nail is provided with a penetrating side hole, the outer sleeve is installed in the proximal side hole of the intramedullary nail in a matching penetrating way, and the tensioning nut and the gasket thereof are supported on the side wall of the side hole of the intramedullary nail. When the intramedullary nail is matched with the device, the key can be arranged on the outer side of the outer sleeve and the key slot is arranged on the side hole of the intramedullary nail by adopting special-shaped hole matching or key matching.
The outer end of the outer sleeve is fixedly provided with a wall plate, the center of the outer sleeve is provided with a perforation, a small knob at the tail end is led out from the perforation, at least one pair of positioning holes are formed in the eccentric position of the end plate, a clamping piece is inserted into each positioning hole, the outer circumferential surface of the tensioning nut is provided with a convex-concave groove, and the clamping piece is clamped in a groove at the outer circumferential side of the tensioning nut. When the gasket consistent with the surface curvature of the bone is sleeved on the inner side of the tensioning nut, the insertion hole can be formed in the gasket, the clamping leading-out fork rod penetrates into the insertion hole, the tensioning nut can be prevented from rotating, and the stability of the outer sleeve can be further improved.
The invention has the beneficial effects that: the device can be conveniently implanted into a femoral medullary cavity and is easy to adjust and fix, and after the blades are unfolded, a reverse hanging mode and an external pulling mode are adopted, so that a plurality of uniformly distributed blades apply tension to the outside at the expansion part of the femoral neck cavity simultaneously, the two ends of a fracture can be promoted to approach inwards, in addition, the fracture part can be effectively prevented from rotating, and the device is simple and reliable to use.
The device provided by the invention can also realize that the blades can be automatically unfolded to different degrees so as to be contacted with the inner cavity wall between the femur tuberosities to form independent hanging relation, so that the blades can bear external pulling pressure, the pulling force is uniformly dispersed, and local overlarge compression is prevented.
Drawings
FIG. 1 is a schematic view of the present invention in use.
FIG. 2 is a schematic diagram of the structure of the present invention.
Fig. 3 is a schematic view of the outer sleeve of fig. 2.
Fig. 4 is a schematic view of the core rod of fig. 2.
Fig. 5 is a schematic view of the blade assembly of fig. 2.
Fig. 6 is a schematic view of a partially enlarged cross-sectional structure of fig. 2.
Fig. 7 is a schematic view of the structure of the blade of fig. 2.
Fig. 8 is a through-nail structure diagram.
Fig. 9 is a drawing of the structure of the sleeve head.
Fig. 10 is a schematic diagram of a fixed-sleeve structure.
Fig. 11 is a diagram of a moving sleeve structure.
FIG. 12 is a second schematic diagram of the structure of the present invention.
Fig. 13 is a schematic view of the blade of fig. 12 in an unfolded state.
Fig. 14 is a block diagram of the blade of fig. 12.
Fig. 15 is a front view of the core pin of fig. 12.
Fig. 16 is a schematic view of a six-blade structure.
Fig. 17 is a schematic view of a ganged blade configuration.
Detailed Description
Example 1: an intramedullary fixing device for femur fracture is shown in figure 1, and is placed in the intramedullary cavity of femur neck fracture position, after the corresponding region is drilled and disinfected, one end of said device is implanted into the deep portion of femur neck intramedullary cavity, and can not be pushed, then the internal several blades can be simultaneously unfolded by means of successively regulating end small knob, and can not be continuously screwed, then the tension nut can be screwed again, so that said device can be wholly withdrawn outwards until the blades are supported in the femur neck inner cavity, and can not be screwed. Thus, the device can be easily implanted in the femoral medullary cavity and easily adjusted and fixed. When the device is used, the tensioning nut presses a steel plate gasket, and the steel plate is matched and attached to the surface of bone.
The specific structure of the device is shown in FIG. 2, and includes outer sleeve 10, core rod 20, and blade set 30, and drive assembly 40.
As shown in fig. 3, a plurality of knife grooves 11 along the axial direction are uniformly distributed on the peripheral edge of the front end pipe orifice of the outer sleeve 10, an annular groove 12 which is inwards recessed near the pipe orifice is formed, a threaded section 13 is arranged on the outer side of the rear end pipe orifice of the outer sleeve, as shown in fig. 2, a tensioning nut 14 is arranged on the outer side of the threaded section 13, and a gasket 15 which is close to the curvature of the bone surface is sleeved on the outer side of the threaded section.
As shown in fig. 4, the core rod 20 includes a screw section 21, and a distal small knob 21 is connected to the rear end of the core rod 20, and the entire core rod 20 can be driven to rotate by rotating the distal small knob 21.
As shown in fig. 1, core rod 20 is fit inside outer sleeve 10, both of which are rotatable.
As shown in fig. 5, the blade set 30 includes a rigid ring 31 and a plurality of blades 32, each blade 32 includes a shaft hole 33 at its distal end and an arcuate cutter head 34 at its head end, each blade 32 is respectively fitted over the rigid ring 31 through the shaft hole 33 at its distal end, and each blade 32 is freely rotatable with respect to the rigid ring 31. During processing, the rigid ring is provided with a notch in advance, the rigid ring is expanded by a tool so that the notch is enlarged, the shaft holes of the blades sequentially penetrate into the rigid ring through the notch, and then the notch is welded, ground and polished.
As shown in fig. 2 and 16, the rigid ring 31 is inserted from the front end of the outer sleeve 10, and the rigid ring 31 can press the end of the outer sleeve 10 to have a properly converged diameter smaller by having a plurality of knife grooves 11, and when the rigid ring 31 is pressed in, the blades are simultaneously arranged so as to be positioned in the corresponding knife grooves 11, and after the rigid ring 31 enters the annular groove 12, the end of the outer sleeve is restored to the natural state. Thus, each blade 32 can freely swing within the corresponding pocket 11.
As shown in fig. 6, the driving assembly 40 includes a fixed sleeve 41 fixed to the front end of the outer sleeve 10 and a movable sleeve 42 screwed to the outside of the core rod screw section 21, and protruding hinge seats 43 are provided at the outer peripheral edges of the movable sleeve 42 (as shown in fig. 8 to 11, which are views of the driving assembly 40), respectively, and shaft holes 44 are provided at the hinge seats 43, respectively, and push-pull rods 36 are hinged through pins, respectively. As shown in fig. 6 and 7, pin holes 35 are further distributed on the inner side of the middle part of each blade 32, and the tail ends of the push-pull rods are hinged in the corresponding pin holes 35 through pin shafts respectively.
As shown in fig. 6, the inner end of core rod 20 is sleeved in a fixed sleeve and can rotate freely. Specifically, a sleeve head 45 is sleeved at the inner end of the mandrel, the sleeve head 45 is matched and sleeved in the central hole of the fixed sleeve 41, as can be seen in the figure, a backing plate 46 is sleeved at the tail end of the mandrel, namely the sleeve head end, the backing plate 46 is fixed at the end of the sleeve head 45 through a penetrating wire 47, the penetrating wire is screwed into the central screw hole 23, and a small matching gap exists between the backing plate 46 and the fixed sleeve 41 so that the backing plate 46 can rotate along with the sleeve head, namely the core rod.
It can be seen that the rigid ring 31 is sleeved and restrained from the outer side of the front end of the outer sleeve 10, and the fixed sleeve 41 is supported from the inner side of the front end opening of the outer sleeve 10, so that under the combined action of the rigid ring 31 and the fixed sleeve 41, both the fixed sleeve and the rigid ring can be firmly fixed at the front end of the outer sleeve. As can be seen, the fixed sleeve 41 is screwed inside the front end port of the outer sleeve.
In order to prevent the fixed sleeve from rotating relative to the outer sleeve, a combined screw hole 48 is arranged at the outer edge of the fixed sleeve and the inner edge of the pipe orifice of the outer sleeve, and a locking wire is arranged. To improve the convenience of the fixing sleeve 41 in mounting and dismounting, a pair of blind holes 49 are formed in the end face of the fixing sleeve, and the fixing sleeve is screwed and assembled by clamping a fork spanner into the corresponding blind holes.
In order to improve the clamping degree of the blade, the outline of the outer edge of the cutter head 34 of the blade protrudes outwards and is provided with teeth, the end part of the cutter head 34 of the blade can also be provided with a hook shape, and the outline of the cutter head of the blade is preferably designed to be approximately matched with the inner wall of the femur neck intramedullary cavity bulge Long Buwei so as to improve the contact area.
From the assembled relationship of fig. 2 and 6, the core 20 can be rotated within the outer sleeve 10 by rotating the end knob 22, but each blade 32 is connected to the movable sleeve 42 by a push-pull rod 36 so that the movable sleeve 42 cannot rotate and thus can move axially along the core as the core rotates. The axial movement of the movable sleeve forces the push-pull rod 36 to drive or pull the respective blade 32 to effect the unfolding or folding action. When the tool is used, the tool is inserted into the femoral neck intramedullary cavity to a deep position along the drill hole, the small knob 22 at the tail end is screwed to enable all the blades to be unfolded at the same time, when the blades are unfolded to a certain degree or are unfolded to the extent that the blades cannot be screwed, the whole outer sleeve is pulled outwards by screwing the tensioning nut 14, and all the blades are further pressed to be clamped on the inner wall of the bulge part of the femoral neck intramedullary cavity, so that a stable supporting relationship is formed.
Example 2: based on the embodiment 1, a fixing device is used which enables each blade to be self-adaptively unfolded. As shown in fig. 15, the core rod 20 has a front end having a front stub shaft 24 with a reduced diameter and a rear end having a rear stub shaft 26 with a reduced diameter, and the front and rear stub shafts are respectively fitted over the front and rear ends of the outer sleeve 10 through bushings 25 and restrained from rotating only and moving axially.
Specifically, the front shaft head 24 at the front end of the core rod is sleeved in the front fixed sleeve 41 through a shaft sleeve, the rear shaft head 26 at the rear end of the core rod is sleeved in the rear fixed sleeve through a shaft sleeve, and the rear fixed sleeve is fixedly arranged at the rear end of the outer sleeve. The front end of the core rod is positioned at the inner side of the positioning sleeve, a steel ring 38 is sleeved at the position, the peripheral edge of the steel ring extends outwards to form an outward-tilted elastic sheet 39, and each elastic sheet 39 respectively passes through the corresponding knife slot 11 and then is supported at the inner side of the corresponding knife blade 32. The pin hole in the middle of the blade is a bar-shaped hole 37, as shown in fig. 14, and the pin shaft at the tail end of the push-pull rod 36 is sleeved in the bar-shaped hole 37 in a matching way and can slide.
Thus, as shown in fig. 12 and 13, when the distal small knob 22 is turned to drive the movable sleeve 42 to move forward, the deployment power of the blades comes from the spring plates 39, instead of the push-pull rod 36, and at this time, the spring plates 32 are deployed as shown in fig. 13, and it should be noted that the extent of the blades will be slightly different, mainly limited by the position and shape of the inner wall of the femoral neck intramedullary cavity, which ensures that all the blades can be deployed and supported on the inner wall of the femoral neck intramedullary cavity. When the tension nut 14 is adjusted, the outer sleeve is driven to move outwards so as to pull the blades to move outwards simultaneously, the blades can be respectively supported on the corresponding positions of the inner side wall of the femoral neck intramedullary cavity to play a supporting role, and the supporting force of the blades is transmitted to the rigid ring 31 through the shaft sleeve 33 at the tail end of the supporting force and then transmitted to the annular groove 12 of the outer sleeve. Similarly, when the tool is removed, the tension nut 14 is first screwed to release the tension of the outer sleeve and the blades, and then the small end knob 22 is turned to drive the movable sleeve 42 to move backward, the unfolding power of the blades comes from the push-pull rods 36, and the tension overcomes the elasticity of the spring plates, so that the spring plates are compressed as shown in fig. 12.
Example 3: based on the embodiment 1 or 2, the invention can adopt six blades which are uniformly arranged at the front end of the outer sleeve, and the passive sleeve and the push-pull rod synchronously drive the expansion and the contraction as shown in fig. 16.
The above examples are only exemplary embodiments of the present invention, and other structural variations of the present invention are possible, such as designing the length of each blade to the ratio of the outer sleeve so that it can be optimally used. However, it is also possible to shorten the length of each blade by increasing the radial extension of each blade as shown in fig. 17. Specifically, each group of blades is additionally provided with an auxiliary rod one 51 and an auxiliary rod two 52 as shown in fig. 17, the auxiliary rod one is respectively sleeved on the rigid ring 31 through the shaft holes at the tail end of the auxiliary rod one, each auxiliary rod one can freely rotate relative to the rigid ring 31, the auxiliary rods are respectively hinged on the shaft holes 44 of the corresponding hinging seats 43 at the outer sides of the movable sleeves through pin shafts, and each auxiliary rod can freely rotate relative to the hinging seat. The middle parts of the auxiliary rod I and the auxiliary rod II are hinged together through a pin shaft 53 respectively. Each blade 32 includes a shaft hole 33 at its end and an arcuate cutter head 34 at its head end, each blade 32 is respectively fitted over the auxiliary lever one through the shaft hole 33 at its end, and each blade 32 is freely rotatable relative to the auxiliary lever one. The two ends of each auxiliary rod are respectively provided with a shaft hole and are respectively hinged with a push-pull rod 36 through a pin shaft. The inner side of the middle part of each blade 32 is also provided with pin holes 35, and the tail ends of the push-pull rods are respectively hinged in the corresponding pin holes 35 through pin shafts. For example, the device is mounted in engagement with an intramedullary nail placed in the femoral cavity. For example, a locking structure is provided at the tightening nut position to prevent rotation thereof, etc.