support orthopaedic device (1) for a knee joint, comprising a proximal connector (2) and a distal connector (3), articulated among themselves and respectively intended to be associated with a proximal bone (100) and a distal bone (101) of a lower limb connected among themselves by a knee joint. The device comprises a first rod (4a) and a second rod (4b), which are hinged, according to hinging axes normal to a median excursion plane of the orthopaedic device (1), to the proximal connector (2) and to the distal connector (3) so as to form with them an articulated quadrilateral. The articulated quadrilateral is planarly mobile according to a plane parallel to the excursion plane between a configuration corresponding to an extended position of the knee joint and configurations corresponding to bendings of different entity of the knee joint; the relative motion imposed to the proximal and distal connectors (2, 3) by the articulated quadrilateral is consistent with the physiological movement of the knee joint.
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0. 26. A method of supporting a joint with an orthopedic support, comprising:
providing a first anchoring device that is fixable to a first bone, a second anchoring device that is fixable to a second bone, and an articulated joint, the articulated joint having a reference aperture defined therein;
implanting the orthopedic support, the implanting including:
inserting a guide into the first or second bone;
positioning the articulated joint to dispose the guide in the reference aperture;
anchoring the first anchoring device to the first bone;
anchoring the second anchoring device to the second bone;
coupling the articulated joint to the first and second anchoring devices; and
removing the guide from the first or second bone during the implanting step,
wherein the steps are performed in the order recited.
0. 27. A method of supporting a joint with an orthopedic support, comprising:
providing a first anchoring device that is fixable to a first bone, a second anchoring device that is fixable to a second bone, and an articulated joint, the articulated joint having a reference aperture defined therein;
implanting the orthopedic support, the implanting including:
inserting a guide into the first or second bone;
positioning the articulated joint to dispose the guide in the reference aperture;
anchoring the first anchoring device to the first bone;
anchoring the second anchoring device to the second bone;
coupling the articulated joint to the first and second anchoring devices; and
removing the guide from the first or second bone during the implanting step, wherein
the first anchoring device includes a longitudinal rail.
0. 31. A method of supporting a joint with an orthopedic support, comprising:
providing a first anchoring device that is fixable to a first bone, a second anchoring device that is fixable to a second bone, and an articulated joint, the articulated joint having a reference aperture defined therein;
implanting the orthopedic support, the implanting including:
inserting a guide into the first or second bone;
positioning the articulated joint to dispose the guide in the reference aperture;
anchoring the first anchoring device to the first bone;
anchoring the second anchoring device to the second bone;
coupling the articulated joint to the first and second anchoring devices; and
removing the guide from the first or second bone during the implanting step, wherein
the second anchoring device includes a rigid partial ring.
0. 25. A method of supporting a joint with an orthopedic support, comprising:
providing a first anchoring device that is fixable to a first bone, a second anchoring device that is fixable to a second bone, and an articulated joint, the articulated joint having a reference aperture defined therein;
implanting the orthopedic support, the implanting including:
inserting a guide into the first or second bone;
positioning the articulated joint to dispose the guide in the reference aperture;
anchoring the first anchoring device to the first bone;
anchoring the second anchoring device to the second bone;
coupling the articulated joint to the first and second anchoring devices; and
removing the guide from the first or second bone during the implanting step, wherein
the inserting includes inserting the guide in a femoral channel in a direction parallel to an articulation axis of a limb including the first and second bones.
0. 13. A support orthopaedic device for a joint, comprising
a first anchoring device operable to be integrally associated with a first bone;
a second anchoring device operable to be integrally associated with a second bone, the first and second bones being connected by a joint;
a first connector operable to be connected to the first anchoring device, a distal portion of the first connector having a reference aperture defined therein, the reference aperture being operable to receive a guide integrally associated with the first bone;
a second connector operable to be connected to the second anchoring device and to articulate with the first connector;
a first rod and a second rod hinged to the first connector and to the second connector to provide a four-bar linkage, the four-bar linkage having a main configuration corresponding to an extended position and a plurality of secondary configurations corresponding to different degrees of bending; and
a lock mechanism operable to lock the four-bar linkage in the main configuration or in any one of the secondary configurations, wherein
at least one of the first and second rods includes a threaded aperture defined therein, and
the lock mechanism includes a locking screw insertable into the threaded aperture and into a slot of one of the first and second connectors, the locking screw being clampable against a wall of the slot to lock the four-bar linkage.
0. 23. A support orthopaedic device for a joint, comprising
a first anchoring device operable to be integrally associated with a first bone;
a second anchoring device operable to be integrally associated with a second bone, the first and second bones being connected by a joint;
a first connector operable to be connected to the first anchoring device, a distal portion of the first connector having a reference aperture defined therein, the reference aperture being operable to receive a guide integrally associated with the first bone;
a second connector operable to be connected to the second anchoring device and to articulate with the first connector;
a first rod and a second rod hinged to the first connector and to the second connector to provide a four-bar linkage, the four-bar linkage having a main configuration corresponding to an extended position and a plurality of secondary configurations corresponding to different degrees of bending; and
a lock mechanism operable to lock the four-bar linkage in a finite plurality of locking configurations, wherein
at least one of the first and second rods includes a threaded aperture defined therein,
the second connector includes a plurality of locking apertures defined therein,
one of the locking apertures of the second connector is aligned with the threaded aperture at a locking configuration, and
a pin is insertable through one of the locking apertures to the threaded aperture to lock the four-bar linkage.
0. 24. A support orthopaedic device for a joint, comprising
a first anchoring device operable to be integrally associated with a first bone;
a second anchoring device operable to be integrally associated with a second bone, the first and second bones being connected by a joint;
a first connector operable to be connected to the first anchoring device, a distal portion of the first connector having a reference aperture defined therein, the reference aperture being operable to receive a guide integrally associated with the first bone;
a second connector operable to be connected to the second anchoring device and to articulate with the first connector;
a first rod and a second rod hinged to the first connector and to the second connector to provide a four-bar linkage, the four-bar linkage having a main configuration corresponding to an extended position and a plurality of secondary configurations corresponding to different degrees of bending; and
a stop mechanism positionable to limit the excursion of the four-bar linkage, the stop mechanism including a stop screw, the stop screw being insertable into an aperture of one of the first and second connectors, and one end of the stop screw is positionable to interfere by contact with at least one of the first and second rods to limit the excursion of the four-bar linkage, wherein
the first connector includes two side walls that rise laterally in relation to a base to form a hinging bracket for the first rod and the second rod,
the first and second rods both include a first segment, hinged to the first connector, with transversal extension equal to the distance between the side walls and a second segment, hinged to the proximal connector, with reduced transversal extension compared to the first segment to allow crossing of the two rods, and
the second connector includes two side-by-side brackets, inside which, according to parallel and offset axis, the second segments of the first rod and the second rod are introduced and hinged.
1. support A support orthopaedic device for a knee joint, comprising
a first anchoring device and a second anchoring device, the first and second anchoring devices being arranged to be integrally associated respectively with a proximal bone and a distal bone of a lower limb, and the proximal bone and the distal bone being connected among themselves by a knee joint,;
a proximal connector and a distal connector, the proximal connector and the distal connector being articulated among themselves and respectively intended operable to be directly connected to said first and a second anchoring devices,;
a first rod and a second rod hinged, according to hinging axes normal to a median excursion plane of the orthopaedic device, to the proximal connector and to the distal connector so as to form with them a four-bar linkage;, said four-bar linkage being planarly mobile according to a plane parallel to the excursion plane between a main configuration corresponding to an extended position of the knee joint and a plurality of secondary configurations corresponding to a different degree degrees of bending of the knee joint, the relative motion imposed to the proximal and distal connectors by the four-bar linkage being consistent with the physiological movement of the knee joint,
wherein said proximal connector presents, in correspondence with one of its distal ends, a includes a reference aperture defined therein at a distal end and normal to the excursion plane, the reference hole, normal to the excursion plane, intended aperture being operable to temporarily house a guide thread integral with the proximal bone to allow the accurate positioning of the proximal connector with respect to the bone,
wherein the device comprises a first means to lock arranged to allow the locking of the four-bar linkage in the main configuration or in any one of its secondary configurations, and
wherein at least one of the first and second rods has a comprises a first transversal threaded aperture defined therein, the first transversal threaded hole with aperture having an axis normal to the excursion plane of the device;, and the first means to lock comprising comprises a locking screw, insertable into the first transversal hole threaded aperture and into a slot of a first septum integral with one of the distal or proximal connectors;, said locking screw being clampable against a wall of the first septum to lock the four-bar linkage in a wanted configuration.
11. support A support orthopaedic device (1) for a knee joint, comprising a proximal connector (2) and a distal connector (3), the proximal connector and the distal connector being articulated among themselves and respectively intended operable to be directly connected to
a first anchoring device and to a second anchoring device (5, 6), the first and second anchoring devices being arranged to be integrally associated respectively with a proximal bone (100) and a distal bone (101) of a lower limb, and the proximal bone and the distal bone being connected among themselves by a knee joint,;
a proximal connector and a distal connector, articulated among themselves and respectively intended to be directly connected to said first and a second anchoring devices; characterised in that it comprises
a first rod (4a) and a second rod (4b); said first and second rods (4a, 4b) being hinged, according to hinging axes normal to a median excursion plane of the orthopaedic device (1), to the proximal connector (2) and to the distal connector (3) so as to form with them an a four-bar linkagearticulated quadrilateral; linkage, said four-bar linkagearticulated quadrilateral linkage being planarly mobile according to a plane parallel to the excursion plane between a main configuration corresponding to an extended position of the knee joint and a plurality of secondary configurations corresponding to different degree of bendings of different entity degrees of bending of the knee joint, the relative motion imposed to the proximal and distal connectors (2, 3) by the four-bar linkagearticulated quadrilateral being consistent with the physiological movement of the knee joint,
wherein said proximal connector (2) presenting, in correspondence with one of its distal ends, a includes a reference aperture defined therein at a distal end and normal to the excursion plane, the reference hole (20), normal to the excursion plane, intended aperture being operable to temporarily house a guide thread (200) integral with the proximal bone (100) to allow the accurate positioning of the proximal connector with respect to the bone,
wherein the device comprises a second means to lock arranged to allow the locking of the four-bar linkage in a finite plurality of possible locking configurations, and
wherein at least one of the first and second rods has a comprises a second transversal aperture defined therein, the second transversal hole with aperture having an axis normal to the excursion plane of the device;, the second means to lock comprising comprises a second septum integral with one of the distal or proximal connectors, said second septum comprises a plurality of locking holes apertures defined therein, one of which the locking apertures of the second septum is aligned with the second transversal hole aperture at a possible locking configuration, and a pin being therefore is insertable through one of the locking holes apertures and the second transversal hole aperture to lock the four-bar linkage in the wanted locking configuration.
12. support A support orthopaedic device for a knee joint, comprising a first anchoring device and a second anchoring device, the first and second anchoring devices being arranged to be integrally associated respectively with a proximal bone and a distal bone of a lower limb, and the proximal bone and the distal bone being connected among themselves by a knee joint,; a proximal connector and a distal connector, the proximal connector and the distal connector being articulated among themselves and respectively intended operable to be directly connected to said first and a second anchoring devices,; a first rod and a second rod hinged, according to hinging axes normal to a median excursion plane of the orthopaedic device, to the proximal connector and to the distal connector so as to form with them a four-bar linkage;, said four-bar linkage being planarly mobile according to a plane parallel to the excursion plane between a main configuration corresponding to an extended position of the knee joint and a plurality of secondary configurations corresponding to different degree degrees of bending of the knee joint, the relative motion imposed to the proximal and distal connectors by the four-bar linkage being consistent with the physiological movement of the knee joint, wherein said proximal connector presents, in correspondence with one of its distal ends, a includes a reference aperture defined therein at a distal end and normal to the excursion plane, the reference hole, normal to the excursion plane, intended aperture being operable to temporarily house a guide thread integral with the proximal bone to allow the accurate positioning of the proximal connector with respect to the bone; the device comprises means to stop positionable to unilaterally limit the excursion of the four-bar linkage so as to limit the bendings bending of the knee joint to a wanted angle, wherein the means to stop comprise comprises a stop screw, the stop screw is insertable into a threaded stop hole integral with aperture defined in one of the proximal and distal connectors and with an axis parallel to the excursion plane of the device, one end of the stop screw being is arranged to interfere by contact with at least one of the first and second rods, by limiting the excursion of the four-bar linkage; wherein the distal connector comprises two side walls which rise laterally in relation to a base to form a hinging bracket for the first rod and the second rod, said first and second rods both having comprise a first segment and a second segment, the respective first segments being hinged to the distal connector, with transversal extension equal to the distance between the side walls, and a the respective second segment, segments being hinged to the proximal connector, with reduced transversal extension compared to the first segment to allow crossing without interference of the two rods;, and the proximal connector comprising comprises two side-by-side brackets, inside which, according to parallel but and offset axis, the second segments of the first rod and the second rod are introduced and hinged.
2. orthopaedic The orthopaedic device 1 according to
3. orthopaedic The orthopaedic device according to
4. orthopaedic The orthopaedic device according to
5. orthopaedic The orthopaedic device according to
6. orthopaedic The orthopaedic device according to
7. orthopaedic The orthopaedic device according to
8. orthopaedic The orthopaedic device according to
9. orthopaedic The orthopaedic device according to
10. orthopaedic The orthopaedic device according to
0. 14. The orthopaedic device according to claim 13, wherein the first connector includes a connector operable to hold a longitudinal rail of the first anchoring device.
0. 15. The orthopaedic device according to claim 13, wherein the second connector includes a connector operable to fasten the second connector to a rigid half ring of the second anchoring device.
0. 16. The orthopaedic device according to claim 13, wherein the first rod and the second rod are crossed at least in the main configuration.
0. 17. The orthopaedic device according to claim 16, wherein a ratio between a distance between the hinging axes of the first and the second rods to the first connector and a distance between the hinging axes of the first and second rods to the second connector is between 3.5 and 4.3.
0. 18. The orthopaedic device according to claim 16, wherein a ratio between distances of the hinging axes of the first rod and distances of the hinging axes of second rod is between 0.9 and 1.1.
0. 19. The orthopaedic device according to claim 16, wherein a ratio between a distance of hinging axes of the first rod and a distance between hinging axes of the first and second rods to the second connector is between 1 and 1.2.
0. 20. The orthopaedic device according to claim 13, wherein
the threaded aperture is defined in the first rod, and
the slot has a shape of a circular arc with a centre on a hinging axis of the first rod to the second connector.
0. 21. The orthopaedic device according to claim 13, further comprising a stop mechanism positionable to limit the excursion of the four-bar linkage.
0. 22. The orthopaedic device according to claim 21, wherein
the stop mechanism includes a stop screw,
the stop screw is insertable into an aperture defined in one of the first and second connectors, and
one end of the stop screw is positionable to interfere by contact with at least one of the first and second rods to limit the excursion of the four-bar linkage.
0. 28. The method according to claim 27, wherein the positioning includes positioning the articulated joint such that the guide passes through the reference aperture.
0. 29. The method according to claim 27, wherein the anchoring the first anchoring device includes clamping the longitudinal rail to a bone screw inserted into the first bone.
0. 30. The method according to claim 27, further comprising adjusting a clamp with respect to the longitudinal rail.
0. 32. The method of claim 31, wherein the anchoring the second anchoring device includes clamping the rigid partial ring to a bone screw inserted into an anterior surface of the second bone.
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This application is a §371 national stage entry of International Application No. PCT/IB2009/006795, filed Sep. 10, 2009, which claims priority to Italian Application No. BO2008A000549, filed Sep. 11, 2008, both of which are hereby incorporated herein by reference in their entirety.
The present invention relates to a support orthopaedic device for a knee joint.
In particular, the device is of the type comprising a proximal connector and a distal connector, articulated to each other and intended to be respectively associated to a femoral bone and to a tibial bone of the lower limb of a patient, these bones being connected to each other through a knee joint.
Knee joint compartments may be subject to surgical operations for trauma or corrective treatment. Such operations, as in the general case of any orthopaedic operation, are characterized by a post-operational period in which the ossification process takes place; in this phase, it is generally necessary to ensure that the joint is not subjected to excessive loads.
The unloading of the joint may be obtained by total immobilization of the knee; on the other hand, this solution has substantial therapeutic drawbacks, and is therefore not often used.
A known alternative solution foresees the use of an orthopaedic device of the type mentioned above, which is provided for allowing partial or total transmission of loads through the operated joint.
In these cases, the proximal and distal connectors are generally associated to anchoring devices, which are respectively associated to the femoral and tibial bones of the patient.
A primary drawback of known orthopaedic devices is the articulation between the two connectors. In fact the relative movement imparted to the two connectors has to be unitary and above all has to reproduce in the most faithful manner possible the movements of the anchoring bones, which are physiologically determined by the natural joint. Such functional conditions are not ensured by simple and efficient constructive morphology. In fact, the coupling provided by the knee joint foresees a combination of rotations and relative slipping among the two affected bones, whose kinematics are difficult to reproduce with a reliable and small-sized mechanism. In fact, such a coupling cannot be reproduced by a simple hinge having a fixed rotational axis. In any case, a system is provided which allows the distraction of the joint, by moving the articulation contact surfaces farther away from each other in order to allow a minimal rotational movement, even if the device does not faithfully reproduce traditional joint movement.
A second problem arising from the therapeutic use of orthopaedic devices according to the known art is the precise positioning of the same device with respect to the bone structure of the patient. In particular, it is of fundamental importance that the articulation of the two connectors is provided on a plane that is normal to the articulation axis of the lower limb. The known anchoring devices are associated, by means of screws, to suitable bone sites on the femur and tibia. The bone surface in these sites is not normal with respect to the articulation axis; as a result there is no morphological reference that may guide the fixing operation of the orthopaedic device. Moreover, the attachment sites are relatively remote from the joint compartment, further complicating the problem regarding a proper positioning of the orthopaedic device.
The technical problem which the present invention has to solve is therefore to provide an orthopaedic device having a structure that overcomes said drawbacks of the known art.
This technical problem is solved by an orthopaedic device of above said type, also comprising a first rod and second rod that are hinged to each other along hinging axes that are normal to a median excursion plane of the orthopaedic device 1 itself, to the proximal connector and to the distal connector, so as to form with them a four-bar linkage. The four-bar linkage is planarly mobile along a plane parallel to the excursion plane, between a main configuration corresponding to an extended position of the knee joint and a plurality of secondary configurations corresponding to different degrees of bending of the knee joint; in particular, the relative motion imposed on the proximal and distal connectors by the four-bar linkage is consistent with the physiological movement of the knee joint.
In general, the idea of the present invention is to reproduce the flexing and extending movements of the knee joint by means of a four-bar linkage, two opposed members of which are provided by the connectors. This constructive solution allows for a reduced size and complexity of the orthopaedic device, while on the other hand ensuring the relative movement of the different elements to reproduce, in a sufficiently faithful manner, the physiological movement of the knee joint.
An advantage of the invention is the fact that the device according to the present invention is easily positioned and modularly assembled with other known orthopaedic devices, ensuring a fast and precise implant.
Further characteristics and advantages will be more clearly understood from the following detailed description of a preferred embodiment of the present invention, which is non-limiting, with reference to the attached figures, which are illustrative but not limiting in scope.
With reference to the appended figures, reference numeral 1 indicates a support orthopaedic device for a knee joint. The primary task of such a device, as already said, is to transmit the same loads that would otherwise act on the joint, allowing for proper healing during the post-surgery period and at the same time ensuring an at least partial mobility of the affected lower limb.
The orthopaedic device 1 comprises a proximal connector 2 and a distal connector 3, which are articulated to each other and are provided to be respectively associated to a proximal bone 100 and distal bone 101 of a lower limb, which are connected to each other by means of the knee joint. In particular, in the preferred embodiment of the appended figures the proximal bone 100 is the femur of the patient, whereas the distal bone 101 is advantageously the tibia.
Said orthopaedic device 1 also comprises a first rod 4a and a second rod 4b, said rods 4a, 4b being hinged, along hinging axes that are normal to a median excursion plane of the same device, to proximal connector 2 and distal connector 3, in order to form a four-bar linkage with them.
The four-bar linkage, which is schematically shown in
The four-bar linkage is planarly mobile according to a plane which is normal to the excursion plane between a main configuration corresponding to an extended position of the knee joint and a plurality of secondary configurations corresponding to different degrees of bending of the knee joint; the relative motion imparted to the proximal and distal connector 2, 3 by the four-bar linkage is consistent with the physiological movement of the knee joint.
As can be seen in attached
The first anchoring device 5, in the preferred embodiment, comprises a longitudinal rail 50, provided with at least a first clamp 51 which may be associated to a femoral surface by means of an assembly of bone screws. The bone screws are advantageously inserted into a femur, which, as previously said, extends along a longitudinal axis x that is not perpendicular to the joint axis y of the limb (in particular, the angle between the two is approximately) 81°. The first clamps 51 may be adjusted with respect to the longitudinal rail 50. The attachment site of the bone screws is preferably located on a lateral surface of the femur; therefore device 1, which is rigidly fixed to the distal end of the longitudinal rail 50, is in a lateral position with respect to the lower limb.
In an alternative embodiment of present invention, not shown, the first anchoring device 5 may comprise a ring, or a ring portion, which is connected to proximal connector 2.
As can readily be seen in
The second anchoring device 6 comprises a rigid half ring 60 and a second clamp 61 that can be associated to a tibial surface by means of bone screws. Thanks to the provision of the rigid half ring it is possible to associate the bone screws of the second clamp 61 to the front surface or middle-front surface of the tibia, taking advantage of the most suitable sites for such an implant.
As discussed before, for a proper operation of the orthopaedic device the excursion plane of the device has to be normal to the articulation axis of the lower limb, identified by x in
In particular, said means for precise positioning comprise a first portion 20a of one of the connectors 2, 3, said portion 20a having at least a reference hole 20 to temporarily receive a guide thread 200 which is fixed to the bone of the corresponding connector; advantageously, the reference hole 20 is normal to the excursion plane.
In the preferred embodiment shown, the first portion 20a is provided on the proximal connector 2, and the reference hole 20 is positioned on a distal end of connector 2, with respect to the proximal bone 100 to which it is associated. In this way, as shown in
From an operational point of view, a method for fixing the device according to the invention to the bone structure of a patient comprises the following steps: an insertion step of a thread in the femoral channels in a direction parallel to the articulation axis y of the limb, followed by anchoring of the proximal connector 2 and the distal connector 3 to the bone structure of patient, by means of said anchoring means 5, 6.
The diagram of
First of all, the four-bar linkage used is a Grashof mechanism, in which the relative excursion of links is however operatively limited at least by the anchoring to the bone structures of the lower limb.
The first and second rod 4a, 4b which comprise the four-bar linkage, cross each other at least in their main configuration. In particular, the four-bar linkage remains inverted for the better part of its operative configurations, wherein by operative configurations one refers to the main configuration and secondary configurations which are operatively feasible. The inverted position of the four-bar linkage allows the instant centre of rotation of the device to be held inside the four-bar linkage's volume, thereby constraining the instant axis of rotation near the knee joint. In fact, as per Chasles' theorem, the instant centre of rotation is at the crossing C of the longitudinal axes z′, z″, shown in
In particular it would be advantageous if an inversion configuration, i.e. a dead point configuration, were to form part of the group of secondary configurations; in this case such a configuration corresponds to a bending at a substantially right angle of the knee joint.
Advantageous dimensional characteristics of the four-bar linkage according to the invention comprise: a ratio of the distance between hinging axes and the first and second rods 4a, 4b of distal connector 3 and the distance between hinging axes and the first and second rods 4a, 4b of the proximal connector 2 higher than 1, and preferably comprised between 3.5 and 4.3 (the value of the ratio in the illustrated embodiment is 43/11); a ratio of the distances of the opposed hinging axes in relation to first and second rods 4a, 4b between 0.9 and 1.1 and preferably equal to 1, as in the illustrated embodiment; ratio of distances of the opposed hinging axes of first rod 4a and the distance between the hinging axes of first and second rods 4a, 4b of distal connector 3 higher than 1 and preferably lower than 1.2 (the value of the ratio in the illustrated embodiment is 47/43). Obviously, all these values are absolutely non-limiting with reference to the present invention.
The orthopaedic device 1 according to the invention advantageously comprises: first locking means 30 provided for locking the four-bar linkage in the main configuration or in any one of its secondary configurations; second locking means 34 provided for locking the four-bar linkage in a finite plurality of possible locking configurations; stop means 37 adjustable for unilaterally limiting the excursion of the four-bar linkage in order to inhibit the bending of the knee joint to which the device 1 is associated.
At least one of first and second rod 4a, 4b comprises a first transversal threaded hole 40a, with axis normal to the excursion plane of device 1; the first locking means 30 comprise a locking screw 31, insertable into the first transversal hole 40a and into a slot 32 of a first septum 33, integral with one of the distal or proximal connectors 2, 3. Therefore the locking screw 31 may be clamped against the wall of the first septum 33 peripheral to slot 32, allowing the four-bar linkage to be locked in a desired configuration.
At least one of the first and second rods 4a, 4b features a second transversal hole 40b with axis normal to the excursion plane of the device 1. The second locking means 34 comprise a second septum 36 integral with one of the distal or proximal connectors 2, 3, which features a plurality of locking holes 35a, 35b (although, as said, the real locking of the device is preferably obtained by means of locking screw 31 of first locking means 30, and these holes are mainly used as references for the degree of articulation bending). Each of the locking holes 35a, 35b is aligned with the second transversal hole 40b at a possible locking configuration. In these configurations, it suffices to insert a pin through the two holes to lock the rod to the connector, therefore locking the four-bar linkage in the desired locking configuration.
In the preferred embodiment shown, the two locking holes 35a, 35b allow the four-bar linkage to be locked in above said main configuration, and in a secondary configuration corresponding to a right angle bend of the limb associated with device 1.
The stop means 37 comprise a stop screw 38, insertable into a threaded stop hole 39. The stop hole 39 is integral with one of the connectors 2, 3 and has an axis which is parallel to the excursion plane of device 1. The end of the stop screw 38 is provided in order to interfere with the movement of at least one of the rods 4a, 4b through contact, limiting the excursion of the four-bar linkage. In this case, it is provided for interfering with the rotation of the second rod 4b.
A rotation of the locking screw 38 about its axis corresponds to its traversing along the axis of locking hole 39; in this way it is possible to modify the position of the end of the screw provided for limiting the angular excursion of rod 4a, 4b, by adjusting the maximum bending angle of the device. Advantageously, the screw and the four-bar linkage are formed in order to provide a substantially linear relationship between the angle of rotation of the screw and variation of the maximum excursion angle of the limb associated to the device 1.
Structurally, the first septum 33, the second septum 36 and stop hole 39 are all integral with the distal connector 3. In particular, this distal connector comprises a base 3a, from which two lateral walls laterally rise, forming a hinging bracket for first rod 4a and second rod 4b. These lateral walls are parallel to the excursion plane of device 1 and are contiguous to both hinged rods 4a, 4b. The first septum 33 and second septum 36, as shown in the appended figures, are part of one of these walls.
The first transversal hole 40a is provided on the first rod 4a, whereas the second transversal hole 40b is provided on the second rod 4b. The rods are preferably identical, with a first segment hinged to distal connector 3, having a transversal extension equal to the distance between the lateral walls of the connector; a second segment, hinged to proximal connector 2, having a reduced transversal extension in order to allow the two members to cross without interference.
Slot 32 has a circular arc shape with centre on the hinging axis of first rod 4a to distal connector 3. The terminal portion of locking screw 31, when unclamped, slides within this circular arc; in any case, slot 32 limits the angular excursion of first rod 4a.
The two lateral walls of distal connector 3, which are inferiorly joined by base 3a, are joined on the upper side by cross beams 3b. Such cross beams are lateral with respect to the free central space inside of which the first and second rod 4a, 4b may move.
One of the beams 3b, in particular the one nearer to the second rod 4b, has a stop hole 39 for inserting the stop screw 38. This beam also has a hole with an axis that is normal to that of the stop hole 39, inside which a screw is inserted that interacts with the stop screw 38 in order to lock it in the desired position.
The base 3a of the distal connector 3 is provided for association with the above-mentioned rigid half ring 60, which is mounted in a distal position underneath the base 3a. To this end, the base 3a provides suitable connecting means, i.e. a central hole 300 on the bottom of the bracket defined by the lateral walls, as well as longitudinal slots 301 provided on a portion of the base which is not surmounted by lateral walls. These openings allow insertion of fixing screws of the rigid half ring 60, as shown in
The proximal connector 2 comprises, at its distal end (also ways referring to the femoral bone, to which it is associated) two side-by-side brackets, into which the second segments of first rod 4a and second rod 4b are inserted and hinged, according to parallel but offset axes. Reference hole 20, which is preferably a through hole, is provided on the distal end of both brackets, in a lateral position with respect to the central free space inside of which first and second rod 4a, 4b may move.
The proximal portion of the proximal connector 2 is advantageously arranged in such a way as to be associated to a longitudinal rail 50 of above said type. To this end, it comprises suitable connection means, i.e. two shaped and parallel grooves 21 and at least one main threaded seat 22 for inserting a locking member 23 of the longitudinal rail.
Obviously, in order to meet contingent and specific needs a person skilled in the art may introduce various modifications and variations to above said orthopaedic device, which are all within the scope of protection of the invention, as defined by the following claims.
Venturini, Daniele, Bagnasco, Mara, Marini, Graziano
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Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Aug 27 2014 | Orthofix S.r.l. | (assignment on the face of the patent) | / | |||
Oct 12 2023 | ORTHOFIX S R L | JPMORGAN CHASE BANK, N A , AS ADMINISTRATIVE AGENT | SECURITY INTEREST SEE DOCUMENT FOR DETAILS | 065381 | /0804 | |
Nov 06 2023 | JPMORGAN CHASE BANK, N A | ORTHOFIX S R L | RELEASE BY SECURED PARTY SEE DOCUMENT FOR DETAILS | 065609 | /0233 |
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