Patent ID: 7434325

Claim:
A system for determining an optimal length for a retractor for use in a minimally invasive procedure with a patient, comprising: a reference instrument extending between a distal end and a proximal end, said reference instrument including a predetermined length between said distal end and an indicator thereon, said distal end being positionable in a portal adjacent to a target location in the patient with said indicator located proximally of an entry location of the portal; and a measurement instrument extending between a distal end and a proximal end, said measurement instrument including indicia extending therealong, wherein when said reference instrument is in the portal with said distal end thereof adjacent the target location and said measurement instrument is positioned along the reference instrument with said distal end of said measurement instrument adjacent the entry location, a location of said indicator of said reference instrument along said indicia of said measurement instrument provides an indication of the optimal length of the retractor for positioning in the portal.