Abstract: An isometer for determining isometric graft tunnel placement for lateral side surgical augmentation or reconstruction for anterolateral or posterior lateral rotary knee instability. This graft tunnel placement isometry assessment and measurement device is designed to be used with a graft and an extra-articular technique that restores rotatory, lateral, and anterior/posterior knee stability when used by itself or in combination with intra-articular ACL/PCL reconstruction. The isometer includes an elongated body with a slider rod that slides horizontally within the body and a cannulated fixed stylus attached transversely to the first end of the elongated body. Within that cannulated fixed stylus is a guide pin that slides freely but that can also be fixed using a fixed-stylus set screw.

Abstract: An isometer for determining isometric graft tunnel placement for lateral side surgical augmentation or reconstruction for anterolateral rotatory knee instability. This graft tunnel placement isometry assessment and measurement device is designed to be used with a graft and an extra-articular technique that restores rotatory, lateral, and anterior knee stability when used by itself or in combination with intra-articular ACL reconstruction. The isometer includes an elongated body with a slider rod that slides horizontally within the body and a cannulated fixed stylus attached transversely to the first end of the elongated body. Within that cannulated fixed stylus is a guide pin that slides freely but that can also be fixed using a fixed-stylus set screw. Similarly, a cannulated movable stylus is attached transversely to the first end of the slider rod, and within that cannulated movable stylus is a guide pin that slides freely but that can also be fixed using a movable-stylus set screw.