As we know, Sasori has
turned his body into a puppet, with a small "core of living flesh" being the only living part of it:
This question also states that when summoned by Edo Tensei,
the reincarnated seem to retain any permanent body damage and physical limitations they received during their lifetime.
Obviously, Sasori would fall under someone who had suffered some physical...limitations. We know that
after being brought back by Edo Tensei, Sasori eventually was released, and vanished like any other summoned shinobi (of flesh and bones), so it clearly wasn't another puppet:
So how was Kabuto able to summon Sasori? If the reincarnation retains body damage, wouldn't he only be able to reincarnate Sasori's "Living Core"? I doubt that the process of "enchanting", which Kabuto can perform, involves re-making the whole body.