Growing Spine Model

Abstract

A spinal surgery modeling system includes a spine model and a spine movement device. The spinal surgery modeling system provides a three-dimensional hands-on model that can be configured to have any desired variation of spinal alignment of the spine model by hydraulic actuation of the spine movement device to simulate the biomechanical feel and behavior of a patient's spine. The spine model may include various vertebral body or disc conditions and allows a clinician to examine and/or adjust the model and observe the three-dimensional outcome of such adjustments.

1 . A spinal construct comprising:
 a plurality of screws; and   an adjustable rod including:
 a hollow member defining a bore therethrough; and 
 a first end member including a first segment in direct slidable engagement with the bore of the hollow member and a second segment securable to at least one screw of the plurality of screws, the first segment having a first shape and the second segment having a second shape different from the first shape, and the bore of the hollow member having a complementary geometry to that of the first segment. 
   
     
     
         2 . The spinal construct according to  claim 1 , wherein the first segment of the first end member is rotationally fixed relative to the hollow member. 
     
     
         3 . The spinal construct according to  claim 1 , wherein the first shape of the first segment of the first end member is an I-beam shape. 
     
     
         4 . The spinal construct according to  claim 1 , wherein the second shape of the second segment of the first end member is a compound shape. 
     
     
         5 . The spinal construct according to  claim 4 , wherein the compound shape includes an elongate round portion, an elongate head portion, and a neck portion connecting the elongate round portion with the elongate head portion. 
     
     
         6 . The spinal construct according to  claim 3 , wherein the bore of the hollow member has an I-beam shape. 
     
     
         7 . The spinal construct according to  claim 1 , wherein the hollow member has a fixed axial length and the bore extends longitudinally through the fixed axial length, and the bore is open at the first and second ends of the hollow member. 
     
     
         8 . The spinal construct according to  claim 1 , wherein the first end member is freely extendable and retractable relative to the hollow member. 
     
     
         9 . The spinal construct according to  claim 1 , wherein the adjustable rod further includes a second end member including a third segment engageable with the bore of the hollow member and a fourth segment securable to at least one screw of the plurality of screws. 
     
     
         10 . The spinal construct according to  claim 9 , wherein the third segment of the second end member has a third shape different from a fourth shape of the fourth segment of the second end member. 
     
     
         11 . The spinal construct according to  claim 9 , wherein the first and second end members are axially movable relative to the hollow member. 
     
     
         12 . The spinal construct according to  claim 11 , wherein the first and second end members are freely extendable and retractable relative to the hollow member. 
     
     
         13 . The spinal construct according to  claim 9 , wherein the second end member has a different range of travel relative to the hollow member than the first end member. 
     
     
         14 . The spinal construct according to  claim 9 , wherein the third segment of the second end member has a third shape that is different from the first shape of the first segment of the first end member. 
     
     
         15 . The spinal construct according to  claim 14 , wherein the first segment of the first end member and the third segment of the second end member are each in direct slidable engagement with the bore of the hollow member. 
     
     
         16 . A spinal construct comprising:
 a plurality of screws; and   an adjustable rod including:
 a hollow member defining a bore therethrough; and 
 a first end member including a first segment in direct slidable engagement with the bore of the hollow member and a second segment securable to at least one screw of the plurality of screws, the first segment having an I-beam shape and the second segment having a compound shape including an elongate round portion, an elongate head portion, and a neck portion connecting the elongate round portion with the elongate head portion, wherein the bore of the hollow member has an I-beam shape. 
   
     
     
         17 . The spinal construct of  claim 16 , wherein the adjustable rod further includes a second end member including a third segment engageable with the bore of the hollow member and a fourth segment securable to at least one screw of the plurality of screws. 
     
     
         18 . The spinal construct of  claim 17 , wherein the first and second end members are axially movable relative to the hollow member. 
     
     
         19 . The spinal construct of  claim 16 , wherein the first segment of the first end member is rotationally fixed relative to the hollow member. 
     
     
         20 . The spinal construct of  claim 16 , wherein the second end member has a different range of travel relative to the hollow member than the first end member.