Lateral disc cutter with replaceable blades

A surgical instrument for removing tissue between adjacent vertebrae of a spine, comprising:

• a cutter assembly, including:
• a blade including a blade end structure;
• and
• a linkage including a linkage end structure that cooperates with said blade end structure to define a pivot joint for rotation of said linkage relative to said blade,
• wherein:
• one of said blade end structure and said linkage end structure includes a spiral-shaped structure that defines and extends along a spiral axis and terminates at a detent, said detent defining a pivot axis, said spiral-shaped structure including an interior surface and an exterior surface that merge at a spiral structure extremity of said detent at said spiral axis, said interior surface defining an arcuate interior channel that extends along and is centered about an arcuate interior axis, said arcuate interior axis defining an axis radius and a circular arc angle about said pivot axis, said circular arc length defining a channel angle about said pivot axis that extends from said spiral structure extremity of said detent to an end of said arcuate interior channel along said arcuate interior axis;
• an other of said linkage end structure and said blade end structure includes a hook-shaped structure having an arcuate end portion that is centered about an end portion axis and terminates at an end portion extremity at said end portion axis, said end portion axis defining an end portion radius that is substantially equal to said axis radius, said end portion axis defining an end portion angle that is equal to or greater than said channel angle, said arcuate end portion being dimensioned for a close sliding fit within said arcuate interior channel.