The first uses of the polymers at the articular level were: joint components, cement fixation of prosthetic components at the bone, and sutures of tendons and ligaments. Since 1970, when polymethyl methacrylate (PMMA) was introduced, bone cement is the choice of choice to fix the prosthetic implant to bone. The cementation of the implant components is a commonly used procedure for hip, knee and shoulder arthroplasty: the femoral stem and the acetabular cup (in the case of total hip arthroplasty), the femoral and tibial components (in the case of total knee arthroplasty), the humeral stem (in hemiarthroplasty, total arthroplasty: anatomical or arthroplasty with inverse shoulder prosthesis) The objectives of this study are to establish the optimal indication of the cementing process, to evaluate and compare the results of cemented hemiarthroplasty, the real benefit from the immediate postoperative functional recovery program, for elderly patients with a diminished bone stock with complex fractures of proximal humerus. The success of the surgical treatment for complex fractures of proximal humerus depends to a large extent on establishing a correct diagnosis, an optimal surgical indication, a thorough preoperative planning, an optimal implant, a periarticular soft tissue reconstruction, and an effective postoperative recovery program.