I am wondering if anyone can give clarification on whether MBB performed on L3, L4, L5, and S1 (on the sacral ala) is coded as 64493 64494 and 64495 or only 64493 and 64494? I am getting conflicting info stating it is for L4/L5, L5/S1 and S1/S2 facet joints and another stating it only involves the L4/L5,and L5/S1. The op report makes no mention of facet joints only that MBB was performed on the L3,L4,LT, and S1 nerves. I need some solid references for the S1 involvement and whether it entails an additional facet joint.

If anyone can recommend an anatomy sheet showing the medial branch targets and the facet joints involved that would be great too!

Thanks in advance!