Sorry to hear about your broken leg. It sounds unusual that your
surgeon would send you to physical therapy for even one session.
Since you are limited in what you can do for one leg, it is a good idea to
perform intense weight training on the rest of your body. There is some,
albeit small crossover effect for any body part when you work other body parts.
Physical exercise of any kind will help your body become more efficient at
strengthening and improving the broken leg. Another good idea is to
perform isometric contractions with your injured leg.
Before weights people exclusively used isometric contraction to build their
bodies. Isometric contractions are when you hold a muscular contraction
such as flexing your biceps with no movement.
Isometric contraction are actually the best way to build and strengthen
muscle! There is a catch though. An isometric contraction only
strengthens the muscle at the angle which the joint is held at. If you
just hold it one angle the rest of the range of motion will not get stronger.
You must perform isometric contractions at all angles for your injured leg.
A way you can do it, is sitting on the couch cross your good leg over your
injured leg. Flex your quadriceps while you apply resistance with your
Hold each angle for around 20-30 seconds and move to another angle. If
you start at 90 degrees and work your way up, your quadriceps will be burning
because you're working it to exhaustion. Do this every other day until you
build enough strength to do other exercises.