You don't only have your patella fractured but also the end of the femur condyle has been screwed on! For immediate guidelines you should have been told in hospital (surgeons instructions?) how much you may partially weightbear whilst it is mending and how to start mobilizing the knee and also maintaining movement of the whole leg during this time. You may need help with issues of swelling and pain and muscle inhibition and that has to be done with a live physio really who can refer back to the surgeon if problems arise rather than online. Get an appointment as soon as possible if you can for outpatient physio. Make sure you combat swelling by NOT sitting around in a chair with the foot on the floor too much but regularly lying flat with the leg supported fully and at a higher level than your hip. Do foot movements dorsal and plantarflexion to help the circulation.