Minimal access lumbar diskectomy instrumentation and method

Abstract

A minimal incision maximal access system allows for maximum desirable exposure along with maximum access to the operative field utilizing a minimum incision as small as the METRx and Endius systems. Instead of multiple insertions of dilating tubes the design is a streamlined single entry device to avoid repetitive skin surface entry. The system offers the capability to expand to optimum exposure size for the surgery utilizing hinged bi-hemispherical or oval working tubes applied over an introducer obturator which is controllably dilated to slowly separate muscle tissue. Deeper end working and visualization areas with maximum proximal access and work dimensions are provided to makes the operative procedure safer in application and shorten the surgeons's learning curve because it most closely approximates the ability to use open microdiskectomy techniques.

1 - 2 . (canceled) 
   
   
       3 . An obturator comprising:
 a first pivoting member having a first end, a second end, and a first pivot surface between said first and second ends, said first pivoting member between said first pivot surface and said first end forming a first exterior hemicylindrical surface;   a second pivoting member having a first end, a second end, and a second pivot surface between said first and second ends and in pivoting contact with said first pivot surface, said second pivoting member between said first pivot surface and said first end forming a second exterior hemicylindrical surface, said first and second exterior hemicylindrical surfaces forming a cylindrical section when brought into close relation with each other; and   a ratchet mechanism connected between said first and said second pivoting members to selectably hold said first and said second exterior hemicylindrical surfaces apart from each other.   
   
   
       4 . The obturator of  claim 3 , wherein said ratchet mechanism further comprises a curved ratchet member having a first end attached to said first pivoting member, said ratchet member having a series of teeth along said curved ratchet member, and a latch supported from and movable with respect to said second pivoting member and a selectably engaging the teeth of said curved ratchet member. 
   
   
       5 . The obturator of  claim 3 , wherein a length between said second ends of said first and said second pivoting members and a pivot point form a manual handle portion and wherein said ratchet mechanism is farther from said pivot point than said manual handle portion. 
   
   
       6 . The obturator of  claim 3 , wherein said first and second pivoting member second ends are hingeably attached to each other. 
   
   
       7 . The obturator of  claim 3 , wherein said first and second pivoting members each form a part of a control shaft for accommodating a guide pin. 
   
   
       8 . The obturator of  claim 3  further including at least one spreading leg, the at least one spreading leg having:
 an upper portion having an insertion tang; and   a lower spreading leg portion having an insertion slot for interfitting with said insertion tang.   
   
   
       9 . An obturator and working tube kit for performing a surgical procedure at a location in a patient's body comprising the obturator of  claim 3  and a working tube.