Lattice isomorphisms of orthodox semigroups with no nontrivial finite subgroups

Two semigroups are lattice isomorphic if their subsemigroup lattices are isomorphic, and a class of semigroups is lattice closed if it contains every semigroup which is lattice isomorphic to some semigroup from that class. An orthodox semigroup is a regular semigroup whose idempotents form a subsemigroup. We prove that the class of all orthodox semigroups having no nontrivial finite subgroups is lattice closed.