Stand-alone access system for minimally invasive spinal surgery

1. A retractor assembly for conducting minimally invasive surgery comprising:

at least three retractor blades that are relatively articulable with respect to each other and are configurable in a self-supporting closed shape for defining a working channel to a surgical site,

each of the retractor blades having a length and inner and outer surfaces joined by two side surfaces,

the retractor blades being configurable such that the lengths of the retractor blades align in a substantially common direction along the working channel and the inner surfaces of the retractor blades face an interior of the working channel,

the side surfaces between adjacent retractor blades comprising mating features configured to abut each other in the form of compression joints to temporarily interconnect the adjacent retractor blades and retain the retractor blades in a desired configuration surrounding the working channel and to constrain a collapse of the retractor blades into the working channel,

wherein at least one of the retractor blades is configured to translate in the substantially common direction relative to the other retractor blades, and at least one of the retractor blades is configured to be pivoted relative to the other retractor blades such that an end of the retractor blade is moved away from a center of the working channel;

interconnections between the retractor blades being limited to the mating features which are shaped to (a) permit relative angular motion between the retractor blades toward and away from the working channel over a continuum of positions along the lengths of the retractor blades and (b) permit relative translation between the retractor blades in the substantially common direction along the working channel.

2. The retractor assembly of claim 1 in which the mating features include male and female features formed in the side surfaces of adjacent retractor blades.

3. The retractor of claim 2 in which the mating feature of one side surface of each of the retractor blades includes a male feature and the mating feature of other side surface of each of the retractor blades includes a female feature.

4. The retractor assembly of claim 2 in which the mating features remain substantially constant through the range of contact positions along a common length of the adjacent retractor blades.

5. The retractor assembly of claim 1 in which joints between the side surfaces of adjacent retractor blades are formed at least in part as mating bevel surfaces.

6. The retractor assembly of claim 1 in which the retractor blades include top and bottom ends, and further comprising an adaptor mounted adjacent to the top end of at least one of the retractor blades and a handle is attached to the one retractor blade through the adaptor.

7. The retractor assembly of claim 1 in which the one of the retractor blades is arranged as a dissecting tool.

8. The retractor assembly of claim 7 in which another of the retractor blades differs from the one retractor blade for performing an additional surgically related function.

9. The retractor assembly of claim 8 in which the another retractor blade is arranged for at least one of propagating light to the surgical site and imaging the surgical site.

10. The retractor assembly of claim 8 in which the another retractor blade is arranged for at least one of irrigating and aspirating the surgical site.

11. The retractor assembly of claim 1 in which additional retractor blades are arranged for individually replacing one or more of the retractor blades performing a different or revised function.

12. The retractor assembly of claim 1 in which the closed shape approximates a triangle for holding a stable shape under compression from surrounding dilated tissue.