Quadriceps strengthening exercises- Quad Clenches: Lie flat on your back or sit upright on a chair with leg kept horizontally on another surface. Now, tighten the muscle on the front of the thigh by pushing your knee down. You should feel your thigh muscles clench, Hold for 3 secs. Repeat 10 times twice a day. Short Arcs: Lie flat on your back or sit upright with your leg placed horizontally on a flat surface like a chair or bed. Place a rolled up towel under the knee. Pull your toes towards you and clench you thigh muscles. Slowly lift your foot up off the bed until your knee is straight (keep your knee resting on the towel). Hold for 3 secs and slowly lower them on the chair. Repeat 10 times twice a day. Straight Leg Raise: Lie flat on your back. One leg and knee will be straight and other leg should be bent. Pull your toes towards you and tighten/clench the muscle on the front of the thigh, locking your knee straight. Lift your foot up in the air, about 6 inches off the bed. Hold for 3 secs and slowly lower the leg. The knee must remain straight the whole time you are doing this exercise.

You should meet a physiotherapist so that you can get the physiotherapy and learn the exercises that you should do on a daily basis to strengthen the muscles over your leg. You should also knowingly take an effort to correct your posture and try to walk as normal as you can. If you feel excessive pain and inability to put any pressure over the leg you should visit your treating orthopedician at the earliest

Hi..It's common thing after surgery when u start independent walk bt u need to consult  physiotherapist near by you and learn strengthening exercise and gait training.proper rehabilitation required.