Abstract
A system for varying distance between bone segments comprises an intramedullary nail (100) and a driving shaft (210). The intramedullary nail (100) comprises a head (110) attached relative to a first bone segment (410); a housing (120) attached with the head (110); a rotational to linear motion convertor mechanism (140) having an input part and an output part (160); and a transmission (130) having an input member (131) & an output member (133), operatively coupled with input part (150) of rotational to linear motion convertor mechanism (140) and configured to transmit rotational motion and power at an angle. Further, at least a portion of the rotational to linear motion convertor mechanism (140) is contained in the housing (120) and the output part (160) is attached relative to a second bone segment (420). Additionally, the driving shaft (210) is configured to detachably connect with an input member (131) of the transmission.
Claims
1. A system for varying distance between bone segments comprises an intramedullary nail (100) and a driving shaft (210); wherein the intramedullary nail (100) comprises: a. a head (110) configured to attach relative to a first bone segment (410); characterized in that b. a housing (120) having at least one axial hole at one end wherein the at least one axial hole is non-circular (125), and said housing is attached with the head (110); c. a rotational to linear motion convertor mechanism (140), wherein at least a portion of the rotational to linear motion convertor mechanism (140) is contained in the housing (120); and wherein an output part (160) of the rotational to linear motion convertor mechanism (140) is configured to attach relative to a second bone segment (420) directly or indirectly and is linearly displaceable relative to the housing (120) and the head (110); d. a transmission (130) configured to transmit rotational motion and power at an angle; wherein output member (133) of the said transmission (130) operatively couples with input part (150) of rotational to linear motion convertor mechanism (140); wherein the driving shaft (210) is configured to detachably connect with an input member (131) of the said transmission (130).
2. The system as claimed in claim 1, wherein the driving shaft (210) upon connection with the input member (131) of the transmission (130) on one end (211), radially comes out of the intramedullary nail (100).
3. The system as claimed in claim 1, wherein the rotational to linear motion convertor mechanism (140) comprises a power screw (150) as an input part and a slider (160) as the output part.
4. The system as claimed in claim 3, wherein the slider (160) is radially non-circular in at least one portion (165), which interfaces with a non-circular axial hole of the housing (125), such that the slider (160) and housing (120) do not rotate relative to each other while axial/linear movement between the housing (120) and the slider (160) is allowed.
5. The system as claimed in claim 4, wherein the slider (160) has at least one axial hole (161), with at least one portion of the said hole has internal threads (163).
6. The system as claimed in claim 3, wherein at least a portion of external threads (151) of the power screw (150) and at least a portion of internal threads (163) of the slider (160) interface with each other, such that rotation of power screw (150) relative to slider (160) displaces the slider (160) relative to the head (110) and the housing (120).
7. The system as claimed in claim 3, wherein the slider (160) may further comprise at least one bulged out portion radially (166), which when approaches proximal the seat (124) or abuts the seat (124), limits the axial/linear displacement of the slider (160) relative to the housing (120).
8. The system as claimed in claim 1, wherein the intramedullary nail (100) may further comprise a distal part (170) configured to be attached with the second bone segment (420) and to rigidly fix with the slider (160).
9. The system as claimed in claim 1, wherein the transmission (130) is configured to do torque multiplication; wherein the rotational motion transmission and the torque multiplication is done in at least one stage.
10. The system as claimed in claim 1, may further comprise a tube (220) that covers over a portion of the driving shaft (210) radially and secures an attachment of driving shaft (210) with the input member (131) of transmission (130).
11. The system as claimed in claim 1, wherein the housing (120) may further be configured to attach with a third bone segment (430) and has at least one elongated hole (128) on the radial surface.
12. The system as claimed in claim 1, wherein the driving shaft (210) may further be configured to attach with a knob or power tool for ease in providing rotation.
13. A system for varying distance between bone segments comprises: an intramedullary nail (100) configured for implanting in the intramedullary cavity (490) of bone; and a driving shaft (210); characterized in that wherein the intramedullary nail (100) comprises a head (110), housing (120), transmission (130) and rotational to linear motion convertor mechanism (140) assembled together; wherein one end (211) of the driving shaft (210) is configured to operatively couple with an input member (131) of said transmission (130) after successful coupling, other end (212) of the driving shaft (210) is accessible from outside a human/animal body (480).
14. The system as claimed in of claim 13, wherein the head (110) is configured to attach relative to a first bone segment (410).
15. The system as claimed in claim 13, wherein the rotational to linear motion convertor mechanism (140) comprises a power screw (150) as an input part and a slider (160) as the output part.
16. The system as claimed in claim 15, wherein the output part (160) of the rotational to linear motion convertor mechanism (140) attaches, directly or indirectly, relative to a second bone segment (420).
17. The system as claimed in claim 13, wherein a rotation of the driving shaft (210) when operatively coupled with the input member (131) of the transmission (130) causes linear displacement of the slider (160) relative to the housing (120) and the head (110).
18. The system as claimed in claim 17, wherein a direction of linear displacement of slider (160) relative to the housing (120) and the head (110) is changed by changing a direction of rotation of the input member (131) of transmission (130).
19. The system as claimed in claim 13, wherein the driving shaft (210) is decoupleable from the input member (131) of transmission (130).
Description
BRIEF DESCRIPTION OF DRAWINGS
[0038] This invention is described by way of example with reference to the following drawings. These drawings being referred herein are for the purpose of illustrating preferred embodiments of the invention only, and not for the purpose of limiting the same.
[0039] FIG. 1. shows an intramedullary nail 100 of a first embodiment of the system, implanted in an intramedullary cavity 490 of a bone, and is connected with different bone segments 410 and 420;
[0040] FIG. 2 shows the intramedullary nail 100 of FIG. 1 further connected with a driving shaft 210 and a tube 220, in accordance with an embodiment of the present invention;
[0041] FIG. 3 shows the intramedullary nail 100 of a second embodiment of the system, which is implanted in the intramedullary cavity 490 of the bone, and is connected with the different bone segments 410, 420, and 430;
[0042] FIG. 4 shows the intramedullary nail 100 of FIG. 3 further connected with the driving shaft 210 and the tube 220, in accordance with an embodiment of the present invention;
[0043] FIG. 5 shows a head 110 of the intramedullary nail 100, in accordance with the embodiments of the present invention;
[0044] FIG. 6 shows a housing 120 of intramedullary nail 100 of the system of FIG. 1 for limb lengthening and bone compression, in accordance with an embodiment of the present invention;
[0045] FIG. 6s shows the sectional view of the housing 120 of FIG. 6, in accordance with an embodiment of the present invention;
[0046] FIG. 7 shows a transmission 130 of intramedullary nail 100, in accordance with the embodiments of the present invention;
[0047] FIG. 7r shows a rotational to linear motion convertor mechanism 140 of intramedullary nail 100, in accordance with the embodiments of the present invention;
[0048] FIG. 8 shows a power screw 150 of the intramedullary nail 100, in accordance with the embodiments of the present invention;
[0049] FIG. 9 shows a slider 160 of the intramedullary nail 100, in accordance with the embodiments of the present invention;
[0050] FIG. 9s shows a sectional view of the slider 160 of FIG. 9, in accordance with the embodiments of the present invention;
[0051] FIG. 10 shows a distal part 170 of the intramedullary nail 100, in accordance with an embodiment of the present invention;
[0052] FIG. 11 shows a driving shaft 210 of the system, in accordance with the embodiments of the present invention;
[0053] FIG. 12 shows a tube 220 of the system, in accordance with the embodiments of the present invention;
[0054] FIG. 13 shows the intramedullary nail 100 of the system of FIG. 1 with sectional view of housing 120, slider 160 and power screw 150;
[0055] FIG. 14 shows displaced slider 160 of the system of FIG. 2, in accordance with an embodiment of the present invention;
[0056] FIG. 15 shows the implanted first embodiment of the system of FIG. 2, in accordance with an embodiment of the present invention;
[0057] FIG. 15g shows a bone segment gap variation done by the first embodiment of the system of FIG. 15, in accordance with an embodiment of the present invention;
[0058] FIG. 16 shows a construction of the intramedullary nail 100 of the system of FIG. 3 for bone transport, with sectional view of housing 120, slider 160 and power screw 150, in accordance with an embodiment of the present invention;
[0059] FIG. 17 shows a housing 120 of intramedullary nail 100 of the system of FIG. 3 for bone transport, in accordance with an embodiment of the present invention;
[0060] FIG. 17s shows the sectional view of the housing 120 of FIG. 17, in accordance with an embodiment of the present invention;
[0061] FIG. 18 shows displaced slider of the system of FIG. 4, in accordance with an embodiment of the present invention;
[0062] FIG. 19 shows the implanted second embodiment of the system of FIG. 4, in accordance with an embodiment of the present invention; and
[0063] FIG. 19g shows the bone segment gap variation done by the second embodiment of the system of FIG. 19, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
[0064] The present invention is described hereinafter by various embodiments with reference to the accompanying drawings, wherein reference numerals used in the accompanying drawings correspond to the like elements throughout the description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, the embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only and are not intended to limit the scope of the invention. In addition, a number of materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary and are not intended to limit the scope of the invention.
[0065] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.
[0066] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, Appearances of the phrase “in an embodiment”, “in another embodiment” and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment. As used throughout this description, the word “may” is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense, (i.e. meaning must). Further, the words “a” or “an” mean “at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope.
[0067] The systems, methods, and examples provided herein are only illustrative and not intended to be limiting.
[0068] In simple terms, the present invention can be understood as a system for treating skeletal deformities. An intramedullary nail fixes to a bone segment on one end. A driving shaft connects to an input member of transmission fitted inside the intramedullary nail on one end and comes out of the body on another end. When the driving shaft is rotated (from out of the body), it transmits that motion to the said transmission. The transmission further transmits that motion to a rotational to linear motion convertor mechanism. The linearly displacing part of said rotational to linear motion convertor mechanism is fixed (in rigid connection) with another bone segment (directly or indirectly). When the linearly displacing part displaces, the bone segment fixed (in rigid connection) to it also displaces, resulting in varying the distance between the bone segments. The resultant displacement between bone segments is prismatic and has only one degree of freedom. The intramedullary nail may be fixed (in rigid connection) to two or more than two bone segments.
The present invention will now be explained with reference to the drawings:
[0069] A system is provided for a varying distance between bone segments, in accordance with the embodiments of the present invention. The proposed invention provides a system that is for varying distance between bone segments by increasing or decreasing the distance between the parts of a system that are fixed (in rigid connection) with different bone segments (directly or indirectly). The system comprises an intramedullary nail, a driving shaft and a tube.
[0070] FIG. 1 shows the intramedullary nail 100 of a first embodiment of the system, implanted in an intramedullary cavity 490 of a bone, and is configured to attach with different bone segments i.e., a first bone segment 410, a second bone segment 420. Further, FIG. 2 shows the first embodiment of the system, where the intramedullary nail 100 is further connected with the driving shaft 210 and the tube 220. And, FIG. 3 shows the intramedullary nail 100 of a second embodiment of the system, which is implanted in the intramedullary cavity 490 of the bone, and is connected with the different bone segments 410, 420 and 430. Furthermore, FIG. 4 shows the second embodiment of the system, wherein the Intramedullary nail 100 is further connected with the driving shaft 210 and the tube 220.
[0071] In accordance with the embodiments of the present invention, the intramedullary nail 100 comprises: a head 110, a housing 120, a transmission 130, and rotational to linear motion convertor mechanism 140. In accordance with an embodiment of the present invention, the intramedullary nail 100 further comprises a distal part 170. The rotational to linear converter mechanism 140 preferably comprise a power screw 150 and a slider 160.
[0072] Additionally, FIG. 5 illustrates the head 110 which is configured to attach with the first bone segment 410 via bone screws 310, through screw holes 111. The head 110 further includes a hole 115 which allows access to input member 131 of transmission 130, another hole 116 to rigidly fix with the housing, a bore 112 with internal threads 113 to connect with a jig and also jig aligners 114.
[0073] Next FIG. 6 shows the housing 120 of first embodiment of the system of—FIG. 1. The housing 120 is a tubular part with an axial hole 122, in which a slider 160 is linearly displaces. The housing 120 has one more axial hole 121 (preferably bigger than the axial hole 122) to fit transmission 130. The housing 120 has a seat 124 to make the axial hole 125 smaller than the axial hole 122 wherein, the seat 124 is configured to restrict/limit the linear displacement of the slider 160 relative to housing 120 as discussed. The shape of at least one of the axial holes 121, 122, 125 of the housing 120 is non-circular. In addition, FIG. 6s shows the housing 120 of the first embodiment of system for limb lengthening and bone compression, wherein the axial hole 125 is non-circular. The housing 120 has one hole 127 radially, for accessing the input member 131 of transmission 130. The housing 120 also has a hole 126 for fastening the housing 120 with the head 110.
[0074] Then, FIG. 7 shows transmission 130 where 131 is input member of transmission 130 and 133 is output member of transmission 130. The input member 131 of transmission 130 when provided with rotational motion results in rotation of output member 133 of transmission 130, wherein axis of rotation of input member of transmission 132 and axis of rotation of output member of transmission 134 are inclined to each other. Preferably the angle between the said axes are between 1 to 179 degree and/or 181 to 359 degree. The transmission 130 is preferably designed to multiply torque.
[0075] Further, FIG. 8 shows a power screw 150 which is a rotating part and an input side of the rotational motion to linear motion convertor mechanism 140. External threads of power screw 151 are preferably buttress, or trapezoidal, or acme or square. Also, FIG. 9 shows a slider 160 which is an output part (i.e., a linearly displacing part) of the rotational to linear motion convertor mechanism 140. The slider 160 is configured with bone screw holes 162 to fix with the second bone segment 420 via the bone screws 320. The slider 160 has an axial hole 161, with internal threads 163 in a portion (as in a nut). The threads 163 are preferably buttress, or trapezoidal, or acme or square. At least a portion of slider 160 linearly displaces/slides in the axial hole 122 of housing 120. A portion of slider 165 is non-circular radially. Preferably the non-circular shape has flat and/or convex walls. Then FIG. 9s shows the sectional view of the slider 160 with a bulged out portion 166 radially, which limits the axial/linear displacement of it relative to the housing 120 when the slider 160 is near the seat 124 or abuts the seat 124.
[0076] After that, the FIG. 10 illustrates a distal part 170 which is configured to fix with slider 160 and also configured to fix with the second bone segment 420 by bone screw(s) 320 passing through bone screw hole(s) 172. The distal part 170 increases stability of the slider 160 when in the intramedullary cavity of bone 490. Further, FIG. 11 shows the driving shaft 210 whose one end 211 is configured to operatively couple with input member 131 of transmission preferably by attachment/connection and its other end 212 is configured for ease in gripping for rotation.
[0077] FIG. 12 shows the tube 220, in accordance with the embodiments of the present invention. The tube 220 when covers over the end 211 of the driving shaft 210 which connects/attaches with input member 131 of transmission 130, such that it's covering secures the said connection/attachment from decoupling by axial pull out, prevents osseointegration over the driving shaft 210 and also supports driving shaft 210. When the tube 220 is employed, its length only allows it to come up to or somewhat out of bone 410 and not out of skin 460.
[0078] FIG. 13 shows a complete construction of the intramedullary nail 100 of the first embodiment of the system for limb lengthening and bone compression with sectional view of the housing 120, the slider 160 and the power screw 150. The head 110 is rigidly fixed with the housing 120. The transmission 130 is accommodated between head 110 and housing 120, where the input member 131 of transmission 130 is accessible from opening 127 and 115, and output member 133 of transmission 130 is operatively coupled with power screw 150. The input member 131 of transmission 130 is configured to attach with driving shaft 210 for operative coupling. The power screw 150 is further in the threaded connection with slider 160 (external threads 151 of power screw interface with internal threads 163 of slider). The radially non-circular portion 165 of slider interfaces with non-circular axial hole 125 of housing, such that slider 160 cannot rotate relative to housing 120. The slider 160 is fixed with the distal part 170.
[0079] Also, FIG. 14 shows displaced slider 160 of the first embodiment of system, wherein the driving shaft 210 is attached with the input member 131 of transmission 130, and tube 220 is slid over driving shaft 210. When driving shaft 210 is rotated, it transmits motion and power to the input member 131 of transmission 130, the transmission 130 transmits the rotational motion and power at an angle and multiplies the torque and gives rotational motion and power at the output member 133 of transmission 130. This output member 133 of transmission 130 rotates power screw 150 as being operatively coupled with it. The power screw 150 being in threaded connection with slider 160 (as external threads 151 of power screw interface with internal threads of slider 163) and slider 160 not being able to rotate relative to the housing 120, the slider 160 gets linearly displaced relative to the housing 120. The distal part 170 also displaces relative to the head 110 and housing 120.
[0080] FIG. 15 shows the first embodiment of system for bone compression and limb lengthening where the head 110 of intramedullary nail 100 is fixed to the first bone segment 410 by bone screws 310, and the slider 160 and the distal part 170 both connect to the second bone segment 420 via bone screws 320. The driving shaft 210 is operatively coupled with the input member 131 of transmission 130 by attachment/connection. The tube 220 is slid over the driving shaft 210 to secure its connection with input member 131 of transmission 130. When the driving shaft 210 is operatively coupled by a physical connection to the input member 131 of transmission 130 it radially comes out of intramedullary nail 100 and it's other end 212 is accessible from out of the body 480.
[0081] FIG. 15g shows the bone gap 440 variation done by the first embodiment of the system of FIG. 15, by rotating the driving shaft 210 when operatively coupled with input member 131 of transmission 130. By changing the direction of rotation of input member 131 of transmission 130 by changing direction of rotation of driving shaft 210 the direction of linear displacement of slider 160 relative to housing 120 (ultimately distal part 170 and the second bone segment 420) can be changed. The driving shaft 210 can be detached (along with tube 220) from the intramedullary nail 100. The intramedullary nail 100 is preferably kept inside the body 470 until the newly generated bone consolidates and can be removed later.
[0082] Additionally, FIG. 16 shows the second embodiment of the system for bone transport. The second embodiment uses similar parts, with similar construction and working to the first embodiment with some design variations in a few parts and its fixation with bone segments. These variations are discussed below. FIG. 16 also shows the complete construction of the second embodiment of nail with sectional view of housing 120, slider 160 and power screw 150. The head 110 is rigidly fixed with the housing 120. The transmission 130 is accommodated between head 110 and housing 120, where the input member 131 of transmission 130 is accessible from opening 127 and 115, and output member 133 of transmission 130 is operatively coupled with power screw 150. The input member 131 of transmission 130 is configured to attach with driving shaft 210 for operative coupling. The power screw 150 is further in the threaded connection with slider 160 (external threads of power screw 151 interface with internal threads 163 of slider). The non-circular portion of slider 165 interfaces with non-circular axial hole 125 of housing 120, such that slider 160 cannot rotate relative to housing 120.
[0083] FIG. 17 shows the housing 120 of the second embodiment. The housing 120 is similar to the first embodiment with few modifications like extended length, bone screw hole(s) 123 radially, working as configuration to connect to the third bone segment 430 via bone screws 330, and elongated holes 128 which allows establishing connection between slider 160 and second bone segment 420. The elongated holes 128 also allow linear displacement of slider 160 and second bone segment 420 when connected together with bone screw 320.
[0084] FIG. 18 shows displaced slider 160 of second embodiment of system, wherein the driving shaft 210 is attached with the input member 131 of transmission 130, and tube 220 is slid over driving shaft 210. When driving shaft 210 is rotated, it transmits motion and power to the input member 131 of transmission 130, the transmission 130 transmits the rotational motion and power at an angle and multiplies the torque and gives rotational motion and power at the output member 133 of transmission 130. This output member 133 of transmission 130 rotates power screw 150 as being operatively coupled with it. The power screw 150 being in threaded connection with slider 160 (as external threads 151 of power screw interface with internal threads 163 of slider) and slider 160 not being able to rotate relative to the housing 120, the slider 160 gets linearly displaced relative to the housing 120.
[0085] FIG. 19 shows the second embodiment of system for bone transport where the head 110 of intramedullary nail 100 is fixed to the first bone segment 410 by bone screws 310, the housing 120 is fixed with the third bone segment 430 by bone screws 330, and the slider 160 is fixed the second bone segment 420 via bone screws 320, wherein constant distance is maintained between first bone segment 410 and the third bone segment 430. The driving shaft 210 is operatively coupled with the input member 131 of transmission 130 by attachment/connection. The tube 220 is slid over the driving shaft 210 to secure its connection with input member 131 of transmission 130. When the driving shaft 210 is operatively coupled by a physical connection to the input member 131 of transmission 130 the other end 212 of it is accessible from out of the body 480.
[0086] FIG. 19g shows a bone gap 440 and 450 variation done by the second embodiment of the system, by rotating the driving shaft 210 when operatively coupled with input member 131 of transmission 130. By changing the direction of rotation of input member 131 of transmission 130 by changing direction of rotation of driving shaft 210 the direction of linear displacement of slider 160 relative to housing 120 (ultimately the second bone segment 420) can be changed. The driving shaft 210 can be detached (along with tube 220) from the intramedullary nail 100 when required. The intramedullary nail 100 is preferably kept inside the body 470 until the newly generated bone consolidates and can be removed later.
[0087] For ease in rotating the driving shaft 210 of the system a part or device can be provided, which is attached to the end of shaft 212. The intramedullary nail 100 of the system is preferably implanted in the intramedullary cavity 490 of bone like tibia, femur, humerus, ulna, and radius. Fracture management by bone compression can be done with the system by decreasing the distance/gap between bone segments.
[0088] The foregoing description describes two embodiments of the present invention. It should be appreciated that these embodiments are described for the purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included in so far as they come within the scope of the invention as claimed or the equivalents thereof.
TABLE-US-00001 LIST OF REFERENCE NUMERALS: No. Denotes 100 Intramedullary nail 110 Head 111 Bone screw hole to connect with first bone segment 112 Bore 113 Threads to attach with Jig 114 Jig aligner 115 Transmission access hole on head 116 Hole for fastening 120 Housing 121 Axial hole for transmission 122 Axial hole for slider 123 Bone screw hole to connect with third bone segment 124 Seat 125 Non-circular hole 126 Hole for fastening 127 Transmission access hole on housing 128 Elongated hole 130 Transmission 131 Input member (of transmission) 132 Axis of rotation of input member (of transmission) 133 Output member (of transmission) 134 Axis of rotation of output member (of transmission) 140 Rotational to linear motion convertor mechanism 150 Power screw 151 External threads 160 Slider 161 Axial hole of slider 162 Bone screw hole to connect with second bone segment 163 Internal threads 164 Radial surface 165 Radially non-circular portion 166 Bulged out portion 170 Distal part 171 Configuration to connect with slider 172 Bone screw hole to connect with second bone segment 210 Driving shaft 211 Configuration for attachment with input member of transmission 212 Driving end (of driving shaft) 220 Tube 310 Bone screw for first bone segment connection 320 Bone screw for second bone segment connection 330 Bone screw for third bone segment connection 410 First bone segment 420 Second bone segment 430 Third bone segment 440 Bone gap between first and second bone segment 450 Bone gap between third and second bone segment 460 Skin 470 Region Inside Body 480 Region outside Body 490 Intramedullary cavity
