ELASTOGRAPHY FOR LIGAMENT CHARACTERIZATION
Methods and system for characterizing ligament properties using elastography are disclosed. An ultrasound system capable of performing shear wave elasticity imaging and/or supersonic shear imaging may retrieve one or more images from a proposed surgical site. The one or more images may be provided to a surgical planning system that identifies one or more properties of ligaments proximate to the surgical site. Musculoskeletal simulations may be performed using the identified properties to preoperatively identify a surgical plan. Preoperative identification of a surgical plan may enable a surgeon to select from more fine-tuning options for a joint replacement than conventional systems.
1 . A method for intraoperative surgical planning for a joint of a patient, the method comprising:
obtaining, by an imaging system, one or more images of an anatomy of the patient proximate to a surgical site prior to making an incision, the anatomy comprising a ligament;
providing the one or more images to a computer-assisted surgical system;
assessing a laxity of the joint using the one or more images and kinematic data captured during a range-of-motion test of the joint; and
displaying, based on the assessing, one or more steps of a surgical plan.
2 . The method of claim 1 , wherein the assessing comprises determining a stiffness measure associated with the ligament from the one or more images using elastography and using the stiffness measure with the kinematic data to perform gap balancing of the joint.
3 . The method of claim 2 , wherein the stiffness measure is determined based on a shear wave propagation velocity through the ligament, the shear wave propagation velocity measured by the imaging system using at least one of shear-wave elasticity imaging or supersonic shear imaging.
4 . The method of claim 1 , further comprising performing, in real-time and in parallel with the range-of-motion test, an elastography analysis to measure a patient-specific strain pattern for the ligament for a given range of motion.
5 . The method of claim 4 , further comprising, after resection of one or more bones and placement of trial implants, performing a second elastography assessment combined with a second range-of-motion test to determine whether a target strain pattern has been achieved.
6 . The method of claim 1 , wherein displaying the one or more steps of the surgical plan comprises displaying, via an augmented reality head-mounted display, a heat map identifying tightness of one or more ligaments surrounding the joint.
7 . The method of claim 1 , wherein displaying the one or more steps of the surgical plan further comprises providing guidance to a user via at least one of a haptic system or an auditory system.
8 . The method of claim 1 , further comprising selecting a thickness of an implant based upon the assessed laxity of the joint.
9 . A surgical system for intraoperative surgical planning for a joint of a patient, the surgical system comprising:
an imaging system configured to obtain one or more images of an anatomy of the patient proximate to a surgical site prior to making an incision, the anatomy comprising a ligament; and
a computer system coupled to the imaging system, the computer system configured to:
receive the one or more images from the imaging system,
assess a laxity of the joint using the one or more images and kinematic data captured during a range-of-motion test of the joint, and
generate one or more steps of a surgical plan based on the assessed laxity.
10 . The surgical system of claim 9 , wherein the computer system is configured to assess the laxity of the joint by determining a stiffness measure associated with the ligament from the one or more images using elastography and using the stiffness measure with the kinematic data to perform gap balancing of the joint.
11 . The surgical system of claim 10 , wherein the stiffness measure is determined based on a shear wave propagation velocity through the ligament, the shear wave propagation velocity measured by the imaging system using at least one of shear-wave elasticity imaging or supersonic shear imaging.
12 . The surgical system of claim 9 , further comprising a tracking system configured to track a position and an orientation of an ultrasound probe of the imaging system, wherein the computer system is further configured to register the one or more images to a preoperative anatomical model associated with the patient based on the tracked position and orientation of the ultrasound probe.
13 . The surgical system of claim 12 , wherein the ultrasound probe comprises an optical tracking array, and wherein the tracking system is configured to determine the position and the orientation of the ultrasound probe based on a position of the optical tracking array.
14 . The surgical system of claim 12 , wherein the ultrasound probe is attached to a robotic arm, and wherein the position and the orientation of the ultrasound probe are determined based on tracking information associated with the robotic arm.
15 . The surgical system of claim 9 , further comprising a display coupled to the computer system, wherein the computer system is further configured to display, via the display, the one or more steps of the surgical plan, and wherein the display comprises an augmented reality head-mounted display configured to display a heat map identifying tightness of one or more ligaments surrounding the joint.
16 . A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:
receiving one or more images of an anatomy of a patient proximate to a surgical site, the one or more images obtained prior to making an incision, the anatomy comprising a ligament;
assessing a laxity of a joint of the patient using the one or more images and kinematic data captured during a range-of-motion test of the joint; and
generating one or more steps of a surgical plan based on the assessed laxity.
17 . The non-transitory computer-readable medium of claim 16 , wherein assessing the laxity of the joint comprises determining a stiffness measure associated with the ligament from the one or more images using elastography and using the stiffness measure with the kinematic data to perform gap balancing of the joint.
18 . The non-transitory computer-readable medium of claim 17 , wherein the stiffness measure is determined based on a shear wave propagation velocity through the ligament, the shear wave propagation velocity determined using at least one of shear-wave elasticity imaging or supersonic shear imaging.
19 . The non-transitory computer-readable medium of claim 16 , wherein the operations further comprise performing, in real-time and in parallel with the range-of-motion test, an elastography analysis to measure a patient-specific strain pattern for the ligament for a given range of motion.
20 . The non-transitory computer-readable medium of claim 19 , wherein the operations further comprise, after resection of one or more bones and placement of trial implants, performing a second elastography assessment combined with a second range-of-motion test to determine whether a target strain pattern has been achieved.