Systems and methods for patient-specific total disc replacement
A method of tailoring a spinal implant to correspond to a specific patient's needs includes: pre-operatively evaluating a patient to determine a desired spinal segment response; and modifying one or more features of flexures of an implant to provide the desired spinal segment response. Modifying one or more features of flexures of the implant can include modifying one or more of a thickness, width, length and/or shape of the features of the flexures. Various systems for executing the methodologies taught herein are also provided.
1 . A method of tailoring a spinal implant to correspond to a specific patient's needs, the method comprising:
pre-operatively evaluating information regarding a patient to determine a desired spinal segment stiffness response, comprising:
determining a first range of motion for a target spinal segment, the first range of motion for the target spinal segment comprising at least two of:
a flexion/extension component;
a lateral bending component;
an axial rotation component; and
a compression component;
wherein the determining the first range of motion for the target spinal segment comprises:
manipulating the target spinal segment within the first range of motion under a load; and
capturing and reviewing images of the target spinal segment as manipulated along the at least two of the flexion/extension component, the lateral bending component, the axial rotation component, and the compression component;
determining a hysteresis curve for the target spinal segment based on the first range of motion as determined from the images; and
modifying one or more flexures of the spinal implant to cause the spinal implant to correspond with the first range of motion of the target spinal segment to provide the desired spinal segment stiffness response.
2 . The method of claim 1 , wherein the first range of motion for the target spinal segment comprises each of the flexion/extension component, the lateral bending component, the axial rotation component, and the compression component.
3 . The method of claim 1 , wherein the capturing and reviewing images comprises capturing and reviewing X-ray images as the patient manipulates a spine of the patient within the first range of motion.
4 . The method of claim 1 , wherein the first range of motion is determined from imaging of markers attached at the target spinal segment while under the load.
5 . The method of claim 1 , wherein the first range of motion is determined from a series of images or video of the target spinal segment under the load.
6 . The method of claim 1 , wherein the determining the hysteresis curve for the target spinal segment further comprises fitting at least one of a Boltzmann curve, a DIP Boltzmann curve, and a freehand curve to data points determined from the images.
7 . A method of tailoring a spinal implant to correspond to a specific patient's needs, the method comprising:
pre-operatively evaluating information regarding a patient to determine a desired spinal segment response, comprising:
determining a first range of motion for a target spinal segment, the first range of motion for the target spinal segment comprising at least two of:
a flexion/extension component;
a lateral bending component;
an axial rotation component; and
a compression component;
wherein the determining the first range of motion for the target spinal segment comprises:
manipulating the target spinal segment within the first range of motion under a first load; and
capturing and reviewing images of the target spinal segment as manipulated along the at least two of the flexion/extension component, the lateral bending component, the axial rotation component, and the compression component;
determining a hysteresis curve for the target spinal segment based on the first range of motion as determined from the images; and
modifying one or more features of the spinal implant to provide the desired spinal segment response.
8 . The method of claim 7 , wherein the method further comprises manipulating a second spinal segment adjacent the target spinal segment within a second range of motion under a second load, and capturing and reviewing images of the second spinal segment as manipulated within the second range of motion.
9 . The method of claim 7 , wherein the method further comprises determining a high-flexibility zone (HFZ) range of motion using a calculation of a percentage of the first range of motion, and wherein the determining the hysteresis curve for the target spinal segment further comprises taking into account the HFZ range of motion as determined from the calculation.
10 . The method of claim 7 , wherein the method further comprises:
determining a high-flexibility zone (HFZ) range of motion by:
manipulating the target spinal segment within the first range of motion under a second load that is less than the first load; and
capturing and reviewing a second set of images of the target spinal segment as manipulated within the first range of motion under the second load,
wherein the determining the hysteresis curve for the target spinal segment further comprises taking into account the HFZ range of motion as determined from the second set of images.
11 . The method of claim 7 , wherein the modifying one or more features of the spinal implant comprises modifying at least one of a thickness, a width, a length, and a shape of one or more flexures of the spinal implant.
12 . The method of claim 7 , wherein the first range of motion for the target spinal segment comprises at least three of the flexion/extension component, the lateral bending component, the axial rotation component, and the compression component.
13 . The method of claim 7 , wherein the first range of motion for the target spinal segment comprises each of the flexion/extension component, the lateral bending component, the axial rotation component, and the compression component.
14 . The method of claim 7 , wherein the determining the hysteresis curve for the target spinal segment further comprises fitting at least one of a Boltzmann curve, a DIP Boltzmann curve, and a freehand curve to data points determined from the images.
15 . A method of tailoring a spinal implant to correspond to a specific patient's needs, the method comprising:
pre-operatively evaluating information regarding a patient to determine a desired spinal segment stiffness response, comprising:
determining a first range of motion for a target spinal segment, the first range of motion for the target spinal segment comprising:
a flexion/extension component;
a lateral bending component;
an axial rotation component; and
a compression component;
wherein the determining the first range of motion for the target spinal segment comprises:
manipulating the target spinal segment within the first range of motion under a first load; and
capturing and reviewing images of the target spinal segment as manipulated along each of the flexion/extension component, the lateral bending component, the axial rotation component, and the compression component;
determining a hysteresis curve for the target spinal segment based on the first range of motion as determined from the images; and
modifying one or more features of the spinal implant to cause the spinal implant to correspond with the first range of motion of the target spinal segment to provide the desired spinal segment stiffness response.
16 . The method of claim 15 , wherein the method further comprises determining a high-flexibility zone (HFZ) range of motion using a calculation of a percentage of the first range of motion, and wherein the determining the hysteresis curve for the target spinal segment further comprises taking into account the HFZ range of motion as determined from the calculation.
17 . The method of claim 16 , wherein the determining the hysteresis curve for the target spinal segment further comprises fitting at least one of a Boltzmann curve, a DIP Boltzmann curve, and a freehand curve to data points determined from the images and the calculation.
18 . The method of claim 15 , wherein the method further comprises:
determining a high-flexibility zone (HFZ) range of motion by:
manipulating the target spinal segment within the first range of motion under a second load that is less than the first load; and
capturing and reviewing a second set of images of the target spinal segment as manipulated within the first range of motion,
wherein the determining the hysteresis curve for the target spinal segment further comprises taking into account the HFZ range of motion as determined from the second set of images.
19 . The method of claim 18 , wherein the determining the hysteresis curve for the target spinal segment further comprises fitting at least one of a Boltzmann curve, a DIP Boltzmann curve, and a freehand curve to data points determined from the images and the second set of images.
20 . The method of claim 15 , wherein the desired spinal segment stiffness response comprises an energy curve corresponding to the hysteresis curve.
21 . The method of claim 15 , wherein the modifying one or more features of the spinal implant comprises modifying at least one of a thickness, a width, a length, and a shape of one or more flexures.
22 . The method of claim 15 , wherein the determining the hysteresis curve for the target spinal segment further comprises fitting at least one of a Boltzmann curve, a DIP Boltzmann curve, and a freehand curve to data points determined from the images.