System and Method for Altering Growth of Bones

Abstract

The present inventions relate to a system and method for altering growth of bones. More precisely, the system is an orthopedic apparatus for correcting rotational deformities and limb length discrepancies. A system of cable-couplings with linking members is used, the linking members being posts or screws traversing bones. Due to the flexibility and adaptability of the system and its components, the cable-coupling members may be installed at varying angles and locations while allowing for growth arrest or rotational corrections of said bones. A method to limit growth using cable-couplings systems is also provided.

Claims

1) An orthopedic fixation device for altering growth of a bone to be used with a growth plate, the device comprising: one bicortical post assembly comprising two telescopic monocortical posts, a first of the two monocortical posts being slideable and rotatable into a second of the two monocortical posts; and two coupling assemblies, each coupling assembly comprising two retaining portions, at least one of the retaining portions being adapted to receive and engage an extremity of the bicortical post assembly, each coupling assembly being positionable on a side of the bone and being adapted to flexibly conform with the side of the bone.

2) (canceled)

3) (canceled)

4) (canceled)

5) The device of claim 1, wherein the first of the two monocortical posts is a male component and the second of the two monocortical posts is a female component, the male component being slideable and freely rotatable into the female component.

6) (canceled)

7) The device of claim 1, each of the monocortical posts comprising a cortical threaded portion adjacent to one of the retaining portions of the coupling assembly.

8) The device of claim 1, each of the monocortical posts comprising a cannulation for guidance over wire.

9) The device of claim 1, each of the monocortical posts comprising a head portion adapted to engage with one of the retaining portions of the coupling assembly.

10) The device of claim 9, the head portion freely rotating when inserted in one of the retaining portions of the coupling assembly.

11) (canceled)

12) (canceled)

13) The device of claim 1, each coupling assembly comprising two coupling members flexibly attached to one another by a flexible tether.

14) (canceled)

15) The device of claim 13, the coupling members moving freely along the flexible tether.

16) (canceled)

17) (canceled)

18) (canceled)

19) (canceled)

20) The device of claim 1, the position of the coupling assemblies being mirrored from one another in view of the center of the growth plate.

21) The device of claim 1, the device stopping the vertical growth of the bone.

22) The device of claim 1, the device comprising two bicortical post assemblies.

23) (canceled)

24) (canceled)

25) (canceled)

26) A coupling assembly positionable on a side of a bone, the coupling assembly comprising: two couplings, each coupling comprising an aperture for receiving a bone fastening element and tethering apertures; and a flexible tethering member received by the tethering apertures and linking the two couplings for the two couplings to be positioned to conform to the side of the bone, wherein the tethering apertures allow free translation of the flexible tethering member.

27) (canceled)

28) The coupling assembly of claim 26, the aperture allowing free rotation of the bone fastening element.

29) (canceled)

30) (canceled)

31) The coupling assembly of claim 26, further comprising at least one crimping element for securing the flexible tethering member to the two couplings.

32) The coupling assembly of claim 31, the at least one crimping element being a sphere secured to an end of the flexible tethering member and having physical dimensions preventing passage through the tethering apertures.

33) (canceled)

34) (canceled)

35) A method for correcting limb length discrepancy or a deformity of a bone using a growth plate, the method comprising: placing a first coupling assembly on one side of the bone to flexibly conform with the side of the bone; placing a second coupling assembly on the other side of the bone to flexibly conform with the side of the bone; adjusting for each of the first and the second coupling assemblies a length between a first coupling and a second coupling by sliding a tethering member through tethering apertures of the first and the second couplings; passing two first fixing elements through in retaining portions of the first coupling assembly; passing two second fixing elements through two retaining portions of the second coupling assembly; threading the fixing elements to the bone above or under the growth plate.

36) (canceled)

37) (canceled)

38) (canceled)

39) (canceled)

40) (canceled)

41) The method of claim 35, further comprising the step of: creating a bicortical post assembly by inserting a male monocortical post into a female monocortical post, the male monocortical post sliding and freely pivoting within the female monocortical post.

42) The coupling assembly of claim 1, further comprising at least one crimping element for securing the flexible tether to the two couplings.

43) The coupling assembly of claim 42, the at least one crimping element being a sphere secured to an end of the flexible tether and having physical dimensions preventing passage through tethering apertures on the two couplings.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and other objects, features and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawings in which:

[0036] FIG. 1 is a front view of an embodiment of a device assembly for guiding growth of bones in accordance with the principles of the present invention, the device assembly being shown with two cable-coupling assemblies and two post assemblies.

[0037] FIG. 2 is a front view of an embodiment of a cable-coupling assembly with a fixed cable length in accordance with the principles of the present invention.

[0038] FIG. 3 is a perspective view of the cable-coupling assembly of [FIG. 2].

[0039] FIG. 4 is an illustration of a multifilament cable and of a crimp in accordance with the principles of the present invention.

[0040] FIG. 5 is a perspective view of an embodiment of a post assembly of the device assembly, the post assembly comprising female and male components.

[0041] FIG. 6 is a cross-sectional view of the post assembly of [FIG. 5].

[0042] FIG. 7 is a perspective view of a female post component of the post assembly of [FIG. 5].

[0043] FIG. 8 is a perspective view of a male post component of the post assembly of [FIG. 5].

[0044] FIG. 9 is a front view of an embodiment of a device assembly for guiding growth of bones in accordance with the principles of the present invention, shown installed in bone, spanning a growth plate and configured to cause growth arrest.

[0045] FIG. 10 is a side view of an embodiment of a device assembly for guiding growth of bones in accordance with the principles of the present invention, shown installed in bone, spanning a growth plate and configured to cause derotation.

[0046] FIG. 11 is a front view of an embodiment of a device assembly for guiding growth of bones in accordance with the principles of the present invention, the device assembly being shown in bone spanning a growth plate and configured to cause rotation and is using cortical screws as fasteners.

[0047] FIG. 12 is a flow chart illustrating a method for using an orthopedic device for growth arrest in accordance with the principles of the present invention.

[0048] FIG. 13 is a flow chart illustrating a method for using an orthopedic device for the correction of rotational deformity in accordance with the principles of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0049] A novel method and system for guiding growth of bones will be described hereinafter. Although the invention is described in terms of specific illustrative embodiment(s), it is to be understood that the embodiment(s) described herein are by way of example only and that the scope of the invention is not intended to be limited thereby.

[0050] Referring to [FIG. 1], an embodiment of an orthopedic device assembly 100 is illustrated. The orthopedic device assembly 100 comprises two cable-coupling assemblies 200 and two post assemblies 300. Each of the post assemblies 300 further comprises a female post 310, post member or component (also shown in [FIG. 7]) and a male post, post member or component 315 (also shown in [FIG. 8]).

[0051] Each of the female 310 and male 315 posts generally include a semi-spherical or conical head 330 and 335, respectively, designed to engage a mating surface in the cable-coupling assembly 200. One of the advantages of having a spherical or conical mating between the posts 310 and 315 and the cable-coupling assemblies 200 is that it allows for non-parallel placement of the metaphyseal posts or cortical screws with regards to the epiphyseal ones. Such non-parallel placement generally aims at allowing more surgical flexibility and at allowing a lower profile and a better contouring of the bone.

[0052] FIGS. 2 and 3 show a cable-coupling assembly 200 wherein FIGS. 5 and 6 show a post assembly 300.

[0053] Now referring to FIGS. 2 and 3, an embodiment of a cable-coupling assembly 200 is illustrated. The cable-coupling assembly 200 comprises a tethering member 210 and two or more couplings, or coupling members, 220. The coupling 220 includes an aperture, or opening or post retaining portion, 230 generally adapted to receive and hold a fastening element such as, but not limited to, the head of a screw or a post. The perimeter of the aperture typically comprises a mating surface 240, such as a shape mating with the coupling, such as a poly-axial spherical mating surface. Each side of the coupling 220 further comprises a passage or aperture 250 adapted to receive the tethering member 210 (e.g. multifilament cable). Understandably, each of the passages 250 may be shaped and positioned at different locations on the coupling 220 to allow passage of the tethering member 210.

[0054] In some embodiments, the tethering member 210 may be flexible, such as being made of any material that exhibits some level of flexibility to follow and/or accommodate unique bone geometries and contours. For example, the tethering member 210 may be made of metal, plastic, polymer, elastomer, any other suitable materials, or any combination thereof. In addition, depending on the intended use of the tethering member 210, the length, width, and thickness of the tether may be varied.

[0055] Now referring to [FIG. 4], the tethering member 210 is embodied as one continuous cable 260 including a crimping component or mechanical fitting 270. In such embodiment, the cable-coupling assembly 200 may be assembled at time of surgery by passing the cable 260 through the passages 250 and by retaining the said cable 250 in the coupling 220, for example by crimping the cable 260 with a crimp 270.

[0056] In some embodiments, a method to install the cable-coupling assembly 200 comprises placing the couplings 220 at the ideal anatomical position before tethering together the epiphyseal coupling 220 to the metaphyseal coupling 220 spanning the growth plate. In some embodiments, the cable 260 may then be crimped at the desired length and the excess cable 260 may be cut off. The couplings 220 generally remain slideable along the cable 260.

[0057] Referring back to FIGS. 2 and 3, in yet another embodiment, the continuous cable 260 is pre-assembled to the two couplings 220 at pre-determined lengths and secured via mechanical fittings such as beads, ball clasps or sleeve crimps 270.

[0058] Now referring to FIGS. 5 to 8, the post assembly 300 may comprise a female 310 and a male component 315. The male component 315 is adapted to slide in and out of the female component 310. Moreover, the male component 315 may also be adapted to freely rotate inside the female component 310 as to allow independent rotation and advancement of components 310 and 315 into the bone. The female 310 and male 315 components typically share a central channel (cannulation) 320 and 325, respectively, used to guide the components 310 and 315 with the help of a guide wire (not shown).

[0059] The female 310 and male 315 components may include a head 330 and 335, respectively, at an extremity, the heads 330 and 335 being adapted to engage the mating surface 240 of the coupling 220. The heads 330 and 335 may have varying shapes allowing the engagement to the mating surface 240, such as but not limited to a semi-spherical shape as shown in embodiments of FIGS. 7 and 8.

[0060] The slideable mating between the female 310 and male 315 components may allow for exact length adjustment to the cortex-to-cortex distance of the post assembly 300 during insertion of said components 310 and 315. Moreover, the components may remain free to telescope after their implantation, allowing for elongation or collapse of said components even when the bone geometry changes over time.

[0061] The female 310 and male 315 components may further comprise a threaded extremity 340 and 345, respectively, adapted to engage the bone portion. In such embodiments, the head is adapted to engage the coupling 220. Each component 310 and 315 may include a recessed drive feature 350 and 355, respectively.

[0062] Now referring to [FIG. 9], for the purpose of causing temporary bone growth arrest, an embodiment of the orthopedic device 400 may be positioned to cover the span of a growth plate in a configuration where, in the sagittal view, the cable-coupling assembly 200 is placed along a bone's longitudinal axis 420. This tethering across the growth plate generally prevents further axial growth, thus causing a temporary growth arrest.

[0063] Referring to FIGS. 10 and 11, for the purpose of correcting rotational deformity, an embodiment of the orthopedic device 500 wherein the cable-coupling assemblies 200, similar to embodiments shown in FIGS. 2 and 3, can be placed to span a growth plate in a configuration where, in the sagittal view, the cable-coupling assemblies are placed at an angle 590 with respect to the anatomical bone axis 520 and that the medial and lateral implant assemblies 201 and 202 are placed at a mirrored angle 590 to the axis 520 (forming an ‘X’). The cable-coupling assemblies 200 may be linked or fixed to the bone via orthopedic fasteners such as, but not limited to, posts or cortical screws.

[0064] Alternatively, in another embodiment (not shown), the cable-coupling assembly may be linked to the bone via a post assembly 300. The angular tethering of the growth plate may lead to rotation in transverse plane as axial growth occurs.

[0065] The present disclosure further provides methods to temporarily prevent bone growth or to correct unwanted rotational deformities. The methods may be used with any embodiment of the orthopedic apparatus 100 presented above, but are not limited therein.

[0066] Referring now to [FIG. 12], a method 600 for using an orthopedic device for growth arrest 400, such as the device shown in [FIG. 9] is illustrated. The method 600 comprises forming a first channel 470 in the epiphysis 430, 610, forming a second channel 480 in the metaphysis 440 along the growth plate plane 410 and inline with respect to the first channel 470, 620, placing a cable-coupling assembly 201 on one side of the bone spanning the growth plate 410, 630 and, inserting a first female post 311 through the epiphyseal coupling 221 and epiphyseal channel 470 and thread into a section of the bone 450, 640. The method 600 may further comprise inserting a second female post 312 through the metaphyseal coupling 222 and channel 480 and thread into a section of the bone 460, 650. The method 600 may further comprise placing a second cable-coupling assembly 202 on the other side of the bone spanning the growth plate 410, 660, inserting a first male post 316 through the epiphyseal coupling 223 and channel 470 engaging the female post 311 and thread into a bone portion 455, 670 and inserting a second male post 317 through the metaphyseal coupling 224 and channel 480 engaging the female post 312 and thread into a bone portion 465, 680. The method 600 generally aims at preventing new bone growth due to the tethering the growth plate 690.

[0067] Referring now to [FIG. 13], a method 700 for using an orthopedic device to correct rotational deformity 500 as seen in FIGS. 10 and 11 is provided. The method 700 generally allows the bone to grow while causing migration and rotation of a metaphyseal post assembly, comprised of posts 312 and 317, in the transverse plane 790. The method 700 comprises forming a first channel 570 in the epiphysis 530, 710, forming a second channel 580 in the metaphysis 540 at an angle 590 with respect to the bone's axis 520, 720 and placing a cable-coupling assembly 201 on one side of the bone spanning the growth plate 510, 730. The method 700 further comprises inserting a first female post 311 through the epiphyseal coupling 221 and the formed epiphyseal channel 570 and threading into the bone 550, 740 and inserting a second female post 312 through the metaphyseal coupling 222 and formed channel 580 and threading into the bone 560, 750. The method 700 further comprises placing a second cable-coupling assembly 202 on the other side of the bone spanning the growth plate 510, 760, inserting a first male post 316 through the epiphyseal coupling 223 and on the other side of the formed channel 570 engaging the female post 311 and threading into the bone 555, 770 and inserting a second male post 317 through the metaphyseal coupling 224 and on the other side of the formed channel 580 engaging the female post 312 and threading into the bone 565, 780. It can be appreciated that any one of the cable-coupling assemblies 201 and 202 may be installed before the other cable-coupling assembly. It can further be appreciated that posts 311, 312, 316 and 317 may be replaced by any other type of fasteners, such as screws in which case there may be two epiphyseal channels 570.1 and 570.2 and two metaphyseal channels 580.1 and 580.2.

[0068] Understandably, the orthopedic device 100 may be adapted to be installed in any type of bone requiring growth restriction.

[0069] In some embodiments, the insertion of female and male posts may be replaced by the insertion of fasteners such as screws.

[0070] While illustrative and presently preferred embodiment(s) of the invention have been described in detail hereinabove, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.