Your legs need even more work to stay strong and give your body the support it requires. Leg routines should include extensions a machine,or with boots. A warm up set followed by an amount of weight you can only get 6 to 8 reps out of souls do the trick.be sure to warmup the knees adquately so to avoid any injury to these vital joints.
You should also do leg presses or the ultimate leg move the squat. Squats with deep breathing are some of the overall best growth and strength exercises, not just for legs but for the whole body.
A routine of squats, heavy bench presses, lat pull downs and overhead presses can be a fabulous overall routine and one that will promote growth If done heavy and slow with good breathing.
Remember as always be sure you are up to this type of routine and your Dr has given you the ok.
Stay strong..live long!