I got my doc up to 150 and then took Living Anatomy at 170. You heal crippled limbs always (I haven't failed once yet, and I've gotten a lot of crippled limbs), and you heal weakening about 90% of the time.
210% is what was needed pre-wipe for the 100% chance (or is it 95%?), I'm not sure if they changed the formula just like how they changed the First Aid/Luck formula.