hi, thank-you for providing the brief history of you. A thorough musculoskeletal assessment and Neuromuscular assessment is advised. As you are having difficulty in lifting the upper limb up whole sitting, standing and lying a thorough assessment is advised. also, you have a small.break at the neck of the humerus undergoing a CT scan can help us understand better the bony strength and weakness. As the muscles of the shoulder girdle are weak Due to pain , you may face the issue with not able to lift the hand up. Performing slow isometric exercises under a physical therapist should help you regain the strength and ROM of the shoulder joint. Also, as the session proceed further the exercises will be changed from isometrics to isotonics. In my clinical experience this should take about a week or two to get rid of the problem Regards Jay Indravadan Patel