The fracture at the elbow doesn't seem to be united though a clearer xray would be required

Hi It's not very rare prob which u r facing. In the human body knee and elbow joints are considered as complex joint,so rehabilitation or regaining full range after surgery or fracture of these two joints need time,patience and most importantly a good physio. Doing exercises in ur own will not help u out much since long time has passed so it needs extensive physiotherapy where they will do stretching and strengthening exercise and prior to hot fomentation will b done which will relax ur muscles to b stretched.