5. Treatment principles (1) Conservative treatment is used for non-displaced stable proximal humerus fractures, and passive joint activities are started early after surgery to avoid shoulder stiffness due to long-term braking. (2) For displaced unstable fractures, incisional internal fixation is preferred in young patients, and anatomic repositioning and stable locking plate fixation are pursued intraoperatively, with aggressive bone grafting to reduce the risk of internal fixation failure. The most common indication for joint replacement is severe osteoporotic four-part fractures in the elderly. Reconstruction of the anatomical proximal humerus obtained through artificial humeral head replacement often results in a pain-free and adequate shoulder joint for daily life. (3) Pay attention to postoperative rehabilitation For incisional reduction and internal fixation, postoperative rehabilitation is about six months, and for artificial humeral head replacement, postoperative rehabilitation is 9-12 months. The picture on the left shows a comparison of the three parts of the proximal humerus with Neer’s fracture after incision and internal fixation The picture on the bottom shows the artificial humeral head after replacement