There is no such element in the latest ver of ANSYS - it was removed with its tetrahedral counterpart (solid72) from v5.7 (approx) onwards I think due to efficiency (too many DOFs i.e. 48 DOF per element!) and element-coupling errors (erroneous results even with consistent DOF). Shells and beams NEED 6 DOF, as mentioned above, and implementing a 6 DOF element would be wasteful, frankly. RIP solid72/3.
I am no specifically looking for that element (SOLID73), which I also heard that performed very badly, but any solid element that permits using shells, beams, and solids all together.
You can use all the standard solids together with shells, beams etc. but you need to write constraint equations to tie the DOF together. If you use ANSYS use the CE command to do this, otherwise check the literature for ways of writing these (*EQUATION etc. for example in ABAQUS).
A number of solid element formulations with rotational DOFs exist and have been proposed over the years.
Cmfg, this paper might help:
"Hybrid stress tetrahedral elements with Allman's rotational D.O.F.s", K. Y. Sze, Y. S. Pan
You can find it in the International Journal for Numerical Methods in Engineering