Systems and methods for intra-operative image analysis

Abstract

A system and method that acquire (i) at least a reference image including one of a preoperative image of a surgical site with skeletal and articulating bones and a contralateral image on an opposite side of the patient from the surgical site, and (ii) at least an intraoperative image of the site after an implant has been affixed to the articulating bone. The system generates at least one reference landmark point on at least one anatomical feature on the articulating bone in the reference image and at least one intraoperative landmark point on that anatomical feature in the intraoperative image. The reference and intraoperative images are compared, and differences between the orientation of the articulating bone in the two images are utilized to analyze at least one of offset and length differential.

What is claimed is: 
     
         1 . A processor-implemented method of estimating one or more post-operative parameters during a surgical procedure, the method comprising:
 registering a preoperative image and an intraoperative image based on an anatomical feature, wherein the anatomical feature is associated with an articulating bone capable of articulating relative to a first bone, wherein the preoperative image comprises a depiction of the first bone and the articulating bone, and the intraoperative image comprises a depiction of at least one portion of the articulating bone, a surgical implant attached to the articulating bone, and the first bone;   determining, based on a first center of rotation of the articulating bone in the registered intraoperative image, an angle of rotation to align a longitudinal axis of the articulating bone in the registered preoperative image with a corresponding longitudinal axis of the articulating bone in the registered intraoperative image;   determining, based on the angle of rotation, a corrected location of the anatomical feature in the registered intraoperative image;   estimating the one or more post-operative parameters based on the corrected location of the anatomical feature in the registered intraoperative image; and   displaying the one or more estimated post-operative parameters.   
     
     
         2 . The method of  claim 1 , wherein the surgical procedure is one of:
 a hip arthroplasty; or   a knee replacement; or   a shoulder replacement; or   a wrist replacement; or   a foot replacement.   
     
     
         3 . The method of  claim 2 , wherein the surgical procedure is the hip arthroplasty, the first bone is a pelvic bone, the articulating bone is a femur, and the one or more estimated post-operative parameters comprise at least one of a leg length, or an offset, or a combination thereof. 
     
     
         4 . The method of  claim 1 , wherein the first center of rotation of the articulating bone in the registered intraoperative image is determined based on one of:
 a second center of rotation, wherein the second center of rotation is associated with the surgical implant in the registered intraoperative image, or   a third center of rotation, wherein the third center of rotation is associated with a digital representation of the surgical implant in the registered intraoperative image.   
     
     
         5 . The method of  claim 1 , wherein the preoperative image is either an ipsilateral image or a flipped contralateral image. 
     
     
         6 . The method of  claim 5 , wherein the preoperative image is the flipped contralateral image and determining the first center of rotation of the articulating bone in the registered intraoperative image comprises:
 determining the first center of rotation of the articulating bone based on the flipped contralateral image.   
     
     
         7 . The method of  claim 1 , further comprising:
 performing, prior to the estimation of the one or more post-operative parameters, at least one of:   scaling at least one of the registered preoperative image or the registered intraoperative image, or   aligning the registered preoperative image and the registered intraoperative image; or   a combination thereof.   
     
     
         8 . The method of  claim 7 , wherein scaling at least one of the preoperative image or the intraoperative image comprises one of:
 scaling the registered preoperative image to a match an intraoperative image scale; or   scaling the registered intraoperative image to match a preoperative image scale; or   rescaling the registered intraoperative image and the registered preoperative image to a consistent scale.   
     
     
         9 . The method of  claim 8 , wherein the consistent scale to effect the rescaling is determined based on one or more of:
 known parameters associated with a radiographic device used to capture the preoperative image and the intraoperative image, or   known dimensions of a marker appearing in the preoperative image and in the intraoperative image, or   direct anatomical measurements, or   known dimensions of the surgical implant.   
     
     
         10 . The method of  claim 7 , wherein the scaling and the aligning are based on stationary base lines in the registered preoperative image and corresponding stationary base lines in the registered intraoperative image, wherein each stationary base line connects feature points on the first bone in the registered preoperative image, and each corresponding stationary base line connects corresponding feature points on the first bone in the registered intraoperative image. 
     
     
         11 . An apparatus to estimate one or more post-operative parameters during a surgical procedure, wherein the apparatus comprises:
 a memory to store a preoperative image and an intraoperative image,   a display, and   a processor coupled to the memory and the display, wherein the processor is configured to:   register the preoperative image and the intraoperative image based on an anatomical feature, wherein the anatomical feature is associated with an articulating bone capable of articulating relative to a first bone, wherein the preoperative image comprises a depiction of the first bone and the articulating bone, and the intraoperative image comprises a depiction of at least one portion of the articulating bone, a surgical implant attached to the articulating bone, and the first bone;   determine, based on a first center of rotation of the articulating bone in the registered intraoperative image, an angle of rotation to align a longitudinal axis of the articulating bone in the registered preoperative image with a corresponding longitudinal axis of the articulating bone in the registered intraoperative image;   determine, based on the angle of rotation, a corrected location of the anatomical feature in the registered intraoperative image;   estimate the one or more post-operative parameters based on the corrected location of the anatomical feature in the registered intraoperative image; and   display the one or more estimated post-operative parameters on the display.   
     
     
         12 . The apparatus of  claim 11 , wherein the surgical procedure is a hip arthroplasty, the first bone is a pelvic bone, the articulating bone is a femur, and the one or more estimated post-operative parameters comprise at least one of a leg length, or an offset or a combination thereof. 
     
     
         13 . The apparatus of  claim 11 , wherein the first center of rotation of the articulating bone in the registered intraoperative image is determined based on one of:
 a second center of rotation, wherein the second center of rotation is associated with the surgical implant in the registered intraoperative image, or   a third center of rotation, wherein the third center of rotation is associated with a digital representation of the surgical implant in the registered intraoperative image.   
     
     
         14 . The apparatus of  claim 11 , wherein the processor is configured to perform, prior to the estimation of the one or more post-operative parameters, at least one of:
 scaling at least one of the registered preoperative image or the registered intraoperative image, or   aligning the registered preoperative image and the registered intraoperative image; or   a combination thereof.   
     
     
         15 . The apparatus of  claim 14 , wherein to perform scaling of at least one of the preoperative image or the intraoperative image, the processor is configured to:
 scale the registered preoperative image to a match an intraoperative image scale; or   scale the registered intraoperative image to match a preoperative image scale; or   rescale the registered intraoperative image and the registered preoperative image to a consistent scale.   
     
     
         16 . The apparatus of  claim 15 , wherein the consistent scale to effect the rescaling is determined based on one or more of:
 known parameters associated with a radiographic device used to capture the preoperative image and the intraoperative image, or   known dimensions of a marker appearing in the preoperative image and in the intraoperative image, or   direct anatomical measurements, or   known dimensions of the surgical implant.   
     
     
         17 . The apparatus of  claim 14 , wherein the scaling and the aligning are based on stationary base lines in the registered preoperative image and corresponding stationary base lines in the registered intraoperative image, wherein each stationary base line connects feature points on the first bone in the registered preoperative image, and each corresponding stationary base line connects corresponding feature points on the first bone in the registered intraoperative image. 
     
     
         18 . A non-transitory computer-readable medium comprising instructions to configure a processor to:
 register a preoperative image and an intraoperative image based on an anatomical feature, wherein the anatomical feature is associated with an articulating bone capable of articulating relative to a first bone, wherein the preoperative image comprises a depiction of the first bone and the articulating bone, and the intraoperative image comprises a depiction of at least one portion of the articulating bone, a surgical implant attached to the articulating bone, and the first bone;   determining, based on a first center of rotation of the articulating bone in the registered intraoperative image, an angle of rotation to align a longitudinal axis of the articulating bone in the registered preoperative image with a corresponding longitudinal axis of the articulating bone in the registered intraoperative image;   determining, based on the angle of rotation, a corrected location of the anatomical feature in the registered intraoperative image;   estimating one or more post-operative parameters based on the corrected location of the anatomical feature in the registered intraoperative image; and   displaying the one or more estimated post-operative parameters.   
     
     
         19 . The computer-readable medium of  claim 18 , wherein the first bone is a pelvic bone, the articulating bone is a femur, and the one or more estimated post-operative parameters comprise at least one of a leg length, or an offset or a combination thereof. 
     
     
         20 . The computer-readable medium of  claim 18 , wherein to estimate the one or more post-operative parameters, the instructions configure the processor to perform, prior to the estimation of the one or more post-operative parameters, at least one of:
 scaling at least one of the registered preoperative image or the registered intraoperative image, or   aligning the registered preoperative image and the registered intraoperative image; or   a combination thereof.