Cannula for receiving surgical instruments

A method for retracting tissue adjacent a spinal location, comprising:

• making an incision in a patient over a spinal location;
• inserting a retractor into the incision;
• positioning the retractor in the patient adjacent the spinal location, the retractor having a proximal portion and a distal portion;
• pivoting the distal portion relative to the proximal portion;
• and
• expanding at least a portion of the distal portion adjacent the spinal location by moving a plurality of discrete segments of the retractor away from each other to retract tissue adjacent the spinal location;
• wherein overlap exists between discrete segments in an unexpanded and an expanded configuration, and wherein expanding at least a portion of the retractor comprises reducing overlap between adjacent discrete segments.

A method for retracting tissue adjacent a spinal location, comprising:

• making an incision in a patient over a spinal surgical location;
• inserting a retractor into the incision in the patient;
• advancing the retractor to a position adjacent the spinal location, the retractor having a proximal end and a distal end, the distal end having a plurality of discrete segments and being positioned adjacent the spinal location and the proximal end being positioned outside of the patient, the retractor having a guiding mechanism including a slot with notches extending transverse to a direction in which the slot extends;
• and
• expanding at least a portion of the retractor adjacent the spinal location by moving a plurality of discrete segments of the retractor away from each other to retract tissue adjacent the spinal location, wherein the discrete segments are moved away from each other by being guided incrementally along successive notches of the guiding mechanism.