You could try something like 0/44/17:
Talent Calculator - World of Warcraft
You lose Impale, Imp. TC, Deflection, and Imp HS but gain prot talents up to Last Stand and defiance. The DPS loss isn't that great compared to a 17/44 spec, and the loss of the early ams talents as an OT aren't too bad. Your biggest challenge as an OT will be generating threat without being beaten on so you have less rage to work with. Defiance helps cover the gap.
I have a feeling I'll be flamed for this build, but I've used it in the past with good results.
Alternatively, you could spec full fury (17/44) and just accept the fact that you'll be handicapped where threat is concerned.