Surgery planning tool for spinal correction rod

Abstract

This invention relates to a surgery planning tool, which is not a patient implant, comprising an elongated body including at least a portion having the shape and the size of a spinal correction rod.

Claims

1. A method comprising: a first step of obtaining two 2D X-ray images of a spine; after the first step, performing a second step of making a patient specific 3D spinal reconstruction from said two 2D X-ray patient images; after the second step, performing a third step of determining a patient specific spinal correction; after the third step, performing a fourth step of manufacturing a surgery planning tool having a shape of a patient specific spinal correction rod implant that is over bended or under bended as compared to a final shape of the spinal correction rod implant after being implanted; visually comparing a shape of the spinal correction rod implant with the shape, and bending the spinal correction rod implant so that the spinal correction rod implant presents curvatures corresponding to the shape; and implanting the spinal correction rod implant such that it assumes the final shape, such that, as a result of the final shape, a straightening effort is exerted on the spine to align with the patient specific spinal correction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an example of a patient radiography and 3D modeling, both frontal view on the left side and sagittal view on the right side, showing patient spine suffering from a scoliosis.

(2) FIG. 2 shows an example of a 3D modeling, posterior view, showing patient spine previously suffering from a scoliosis but now straightened by two spinal correction rod implants.

(3) FIG. 3 shows an example of a 3D modeling, sagittal view, showing patient spine previously suffering from a scoliosis but now straightened by two spinal correction rod implants.

(4) FIG. 4A shows an example of a surgery planning tool according to a first embodiment of the invention.

(5) FIG. 4B shows another example of a surgery planning tool according to a first embodiment of the invention.

(6) FIG. 5 shows an example of a surgery planning tool according to a second embodiment of the invention.

(7) FIG. 6A shows an example of a front view of a surgery planning tool according to a third embodiment of the invention.

(8) FIG. 6B shows an example of a back view of a surgery planning tool according to a third embodiment of the invention.

(9) FIG. 7A shows an example of a front view of a surgery planning tool according to a fourth embodiment of the invention.

(10) FIG. 7B shows an example of a back view of a surgery planning tool according to a fourth embodiment of the invention.

(11) FIG. 8 shows an example of a surgery planning tool according to a fifth embodiment of the invention.

(12) FIG. 9 shows an example of a surgery planning tool according to a sixth embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(13) FIG. 1 shows an example of a patient radiography and 3D modeling, both frontal view on the left side and sagittal view on the right side, showing patient spine suffering from a scoliosis. The patient 10 can be seen as well as her or his patient vertebral spine 11.

(14) On the left side of FIG. 1, when looking at the frontal view of the patient spine, if the patient was in good health, one should see a straight patient vertebral spine, which is not at all the case. On the contrary, patient vertebral spine 11 shows, in the frontal plane, a big curvature corresponding to an important scoliosis. This important scoliosis is to be corrected by implementing, respectively on both sides of this patient spine 11, two spinal correction rod implants which will straighten this curved patient spine 11.

(15) On the right side of FIG. 1, when looking at the sagittal view of the patient spine, if the patient was in good health, one should see a patient vertebral spine corresponding to a typical kyphosis for upper part 15 of patient spine 11 and to a typical lordosis for lower part 16 of patient spine 11, what is not exactly the case. These incorrect kyphosis and lordosis are to be corrected by implementing, respectively on both sides of this patient spine 11, two spinal correction rod implants which will change the respective curvatures of kyphosis and lordosis of this patient spine 11.

(16) FIG. 2 shows an example of a 3D modeling, posterior view, showing patient spine previously suffering from a scoliosis but now straightened by two spinal correction rod implants.

(17) The important scoliosis, which could be seen on FIG. 1, was corrected by implementing, respectively on both sides of this patient spine 11, two spinal correction rod implants 12 and 13 which have straightened this curved patient spine 11. Both spinal correction rod implants 12 and 13 are fixed on patient spine 11 by screws 14. The screws 14 have been screwed in the vertebra of patient spine 11. The head of each screw 14 includes a slit in which the spinal correction rod implant 12 or 13 is held in place. Both spinal correction rod implants 12 and 13, being fixed on patient spine 11 by screws 14, and being straight and rigid because being made of metal, exert a constraint on patient spine 11, thereby straightening patient spine 11.

(18) FIG. 3 shows an example of a 3D modeling, sagittal view, showing patient spine previously suffering from a scoliosis but now straightened by two spinal correction rod implants.

(19) The incorrect kyphosis and lordosis, which could be seen on FIG. 1, were corrected by implementing, respectively on both sides of this patient spine 11, two spinal correction rod implants 12 and 13 (only spinal correction rod implant 13 can be seen on FIG. 3) which have changed the respective kyphosis and lordosis curvatures of this curved patient spine 11. Both spinal correction rod implants 12 and 13 are fixed on patient spine 11 by screws 14. The screws 14 have been screwed in the vertebra of patient spine 11. The head of each screw 14 includes a slit in which the spinal correction rod implant 12 or 13 is held in place. Both spinal correction rod implants 12 and 13, being fixed on patient spine 11 by screws 14, and being correctly curved and rigid because being made of metal, exert a constraint on patient spine 11, thereby changing and making correct the respective kyphosis and lordosis curvatures of respectively the upper part 15 and lower part 16 of this curved patient spine 11.

(20) FIG. 4A shows an example of a surgery planning tool according to a first embodiment of the invention.

(21) Once the surgery planning is made with planning software, the lengths and shapes of the rods are used to produce the planning templates which are the surgery planning tools. These planning templates are 3D printed and then sterilized, for instance with gamma ray sterilization, and sent to the hospital for the surgery.

(22) The surgery planning tool 1 is no patient implant. The surgery planning tool 1 comprises an elongated body 9 which includes at least a portion having the shape and the size of a spinal correction rod. Here, this elongated body 9 as a whole has the shape and the size of the spinal correction rod implant it represents. This elongated body 9 has the length and the curvature of the spinal correction rod implant it represents.

(23) The surgery planning tool 1 is a 3D (three dimensional) printed plastic rod which is in two parts, an upper part 3 and a lower part 4, which can be fastened together, via a quick quarter turn fastener 2.

(24) The surgery planning tool 1, which is the planning template, can have a length too long to be printed in one part, thus this template can be printed in two parts 3 and 4, and the two parts 3 and 4 are assembled during the surgery preparation using a printed fixation part 2 such as a quick quarter turn fastener.

(25) On the end of upper part 3 there is a piece of information 7 about patient and/or patient spinal correction which has been etched in the plastic. On the end of lower part 4 there is a piece of information 8 about patient and/or patient spinal correction which has been etched in the plastic.

(26) At upper end of surgery tool 1, there is an upper plate 5 which first indicates it is the upper end and which second allows for the surgeon to more easily manipulate the surgery planning tool 1, by holding this upper plate 5 firmly and precisely between her or his fingers, the plan of this upper plate 5 being in the sagittal plane of the surgery planning tool 1. At lower end of surgery tool 1, there is an lower plate 6 which first indicates it is the lower end and which second allows for the surgeon to more easily manipulate the surgery planning tool 1, by holding this lower plate 6 firmly and precisely between her or his fingers, the plan of this lower plate 6 being in the sagittal plane of the surgery planning tool 1 and being in the same plan as the upper plate 5.

(27) By visually comparing the straight and long original rod with this surgery planning tool 1, the surgeon first cuts the original rod either at the same length as this surgery planning tool 1 or slightly longer, and second bends the cut rod so that this rod presents the same curvatures, kyphosis and lordosis, as the surgery planning tool 1. Afterwards, if applicable, the surgeon may again cut the already cut and bent rod at the same length as this surgery planning tool 1. When this cut and bent rod presents the same length and the same curvature as this surgery planning tool 1, it can be implemented as a spinal correction rod implant within patient body.

(28) FIG. 4B shows another example of a surgery planning tool according to a first embodiment of the invention.

(29) The surgery planning tool 1 comprises an elongated body 9 which includes at least a portion having the shape and the size of a spinal correction rod. Here, this elongated body 9 as a whole has the shape and the size of the spinal correction rod implant it represents. This elongated body 9 has the length and the curvature of the spinal correction rod implant it represents.

(30) The surgery planning tool 1 is a 3D (three dimensional) printed plastic rod which is in three parts, an upper part 3, an intermediate part 103 and a lower part 4, which can be fastened together, via two quick quarter turn fasteners 2 and 102. Upper part 3 and intermediate part 103 can be fastened together, via a two quick quarter turn fastener 2. Intermediate part 103 and lower part 4 can be fastened together, via a two quick quarter turn fastener 102.

(31) The surgery planning tool 1, which is the planning template, can have a length too long to be printed in one part, thus this template can be printed in three parts 3, 103 and 4, and the three parts 3, 103 and 4 are assembled during the surgery preparation using printed fixation parts 2 and 102 such as quick quarter turn fasteners.

(32) On the end of upper part 3 there is a piece of information 7 about patient and/or patient spinal correction which has been etched in the plastic. On the end of lower part 4 there is a piece of information 8 about patient and/or patient spinal correction which has been etched in the plastic. On the middle of intermediate part 103 there is a piece of information 107 about patient and/or patient spinal correction which has been etched in the plastic.

(33) At upper end of surgery tool 1, there is an upper plate 5 which first indicates it is the upper end and which second allows for the surgeon to more easily manipulate the surgery planning tool 1, by holding this upper plate 5 firmly and precisely between her or his fingers, the plan of this upper plate 5 being in the sagittal plane of the surgery planning tool 1. At lower end of surgery tool 1, there is an lower plate 6 which first indicates it is the lower end and which second allows for the surgeon to more easily manipulate the surgery planning tool 1, by holding this lower plate 6 firmly and precisely between her or his fingers, the plan of this lower plate 6 being in the sagittal plane of the surgery planning tool 1 and being in the same plan as the upper plate 5.

(34) FIG. 5 shows an example of a surgery planning tool according to a second embodiment of the invention.

(35) The surgery planning tool 20 comprises an elongated body 29 which includes a hollow 21 formed by a cavity 21 having the shape and the size, and more precisely the curvature and the length, of a spinal correction rod implant. The elongated body 29 of the surgery planning tool 20 has a shape complementary to spinal correction rod implant. The spinal correction rod implant can then be put within the cavity 21 and rests against the back of the cavity 21, allowing for the surgeon to see if its shape and size are satisfactory or if this spinal correction rod implant still needs cutting and/or bending to be performed by the surgeon. This cavity 21 is surrounded by an edge 22. At both extremities of the cavity 21 are located ends 23 of this edge 22. On this edge 22 are printed one or more pieces of information 27 containing information about the patient and about the spinal correction rod implant to be implemented in this patient spine by the surgeon. The surgeon will get two such surgery planning tools 20, one for each spinal correction rod implant.

(36) FIG. 6A shows an example of a front view of a surgery planning tool according to a third embodiment of the invention.

(37) The surgery planning tool 30 comprises an elongated body 39 which includes two hollows 31 formed by two cavities 31 having the shape and the size, and more precisely the curvature and the length, respectively of two spinal correction rod implants to be implemented respectively on both sides of the patient spine. The elongated body 39 of the surgery planning tool 30 has a shape complementary to both spinal correction rod implants. Each spinal correction rod implant can then be put within its cavity 31 and rests against the back of its cavity 31, allowing for the surgeon to see if its shape and size are satisfactory or if this spinal correction rod implant still needs cutting and/or bending to be performed by the surgeon. These cavities 31 are surrounded by an edge 32. A wall 34 is located between both cavities 31. At both extremities of these cavities 31 are located ends 33 of this edge 32. On this edge 32 is printed no information. The information about the patient and about the spinal correction rod implant to be implemented in this patient spine by the surgeon will be provided on another support like a sheet of paper being packed in the same package as the surgery planning tool 30.

(38) FIG. 6B shows an example of a back view of a surgery planning tool according to a third embodiment of the invention.

(39) A flange 35 surrounds the edge 32. This flange 35 is sufficiently protruding so that the surgery planning tool 30 back rests on this flange 35 and not on the back of the cavities 31, although the cavities 31 have a given depth, when this surgery planning tool 30 rests on its back.

(40) FIG. 7A shows an example of a front view of a surgery planning tool according to a fourth embodiment of the invention.

(41) The surgery planning tool 40 comprises an elongated body 49 which includes two hollows 41 formed by two cavities 41 having the shape and the size, and more precisely the curvature and the length, respectively of two spinal correction rod implants to be implemented respectively on both sides of the patient spine. The elongated body 49 of the surgery planning tool 40 has a shape complementary to both spinal correction rod implants. Each spinal correction rod implant can then be put within its cavity 41 and rests against the back of its cavity 41, allowing for the surgeon to see if its shape and size are satisfactory or if this spinal correction rod implant still needs cutting and/or bending to be performed by the surgeon. These cavities 41 are surrounded by an edge 42. A wall 44 is located between both cavities 41. At only one extremity of these cavities 41 is located an end 43 of this edge 42. At the other extremity of these cavities 41 is located no end 43 of this edge 42, but an opening 46 of this edge 42. There is a stop 43, for stopping the spinal correction rod implants, only at one extremity of these cavities 41 and not at the other extremity. On this edge 42 are printed one or more pieces of information 47 containing information about the patient and about the spinal correction rod implant to be implemented in this patient spine by the surgeon.

(42) FIG. 7B shows an example of a back view of a surgery planning tool according to a fourth embodiment of the invention.

(43) Four corners 45 surround the edge 42. These four corners 45 are sufficiently protruding so that the surgery planning tool 40 back rests on these corners 45 and not on the back of the cavities 41, although the cavities 41 have a given depth, when this surgery planning tool 40 rests on its back. Four corners 45 are more stable than a flange 35 as on FIG. 6B.

(44) Surgery planning tools 20, 30 and 40, represented on FIGS. 5, 6A, 6B, 7A and 7B, allow for the surgeon to check more precisely the correctness of length and curvature of the spinal correction rod implants, than the surgery planning tools 50 and 60, represented on FIGS. 8 and 9, thanks to the existing back of the cavities 21, 31 and 41.

(45) FIG. 8 shows an example of a surgery planning tool according to a fifth embodiment of the invention.

(46) The surgery planning tool 50 comprises an elongated body 59 which includes two hollows 31 formed by two through holes 51 having the shape and the size, and more precisely the curvature and the length, respectively of two spinal correction rod implants to be implemented respectively on both sides of the patient spine. The elongated body 59 of the surgery planning tool 50 has a shape partially complementary to both spinal correction rod implants. Each spinal correction rod implant can then be put just in its through hole 51 without going completely through the elongated body 59, allowing for the surgeon to see if its shape and size are satisfactory or if this spinal correction rod implant still needs cutting and/or bending to be performed by the surgeon. These through holes 51 are surrounded by an edge 52. A wall 54 is located between both through holes 51. At both extremities of these through holes 51 are located ends 53 of this edge 52. On this edge 52 are printed one or more pieces of information 57 containing information about the patient and about the spinal correction rod implant to be implemented in this patient spine by the surgeon.

(47) FIG. 9 shows an example of a surgery planning tool according to a sixth embodiment of the invention.

(48) The surgery planning tool 60 comprises an elongated body 69 which includes two hollows 61 formed by two through holes 61 having the shape and the size, and more precisely the curvature and the length, respectively of two spinal correction rod implants to be implemented respectively on both sides of the patient spine. The elongated body 69 of the surgery planning tool 60 has a shape partially complementary to both spinal correction rod implants. Each spinal correction rod implant can then be put just in its through hole 61 without going completely through the elongated body 69, allowing for the surgeon to see if its shape and size are satisfactory or if this spinal correction rod implant still needs cutting and/or bending to be performed by the surgeon. These through holes 61 are surrounded by an edge 62. A wall 64 is located between both through holes 61. At both extremities of these through holes 61 are located ends 63 of this edge 62. On this edge 62 are printed one or more pieces of information 67 containing information about the patient and about the spinal correction rod implant to be implemented in this patient spine by the surgeon. The elongated body 69 comprises two hinged parts 65 and 66 which are foldable over each other so as to reduce the length of said elongated body 69, said parts 65 and 66 being hinged preferably in the middle of said elongated body 69. There is a hinge 68 between said parts 65 and 66.

(49) Surgery planning tools 50 and 60, represented on FIGS. 8 and 9, are less bulky and easier to conceive, than the surgery planning tools 20, 30 and 40, represented on FIGS. 5, 6A, 6B, 7A and 7B, thanks respectively to the flatness of these surgery planning tools 50 and 60, and to their only partially complementary shape to the spinal correction rod implants.

(50) The invention has been described with reference to preferred embodiments. However, many variations are possible within the scope of the invention.