Some proximal humeral fractures in elderly patients are accompanied by medial metaphyseal comminution and quality of the bone is so poor that head preserving osteosynthesis seems to be amenable. In cases of medial metaphyseal comminution, lateral locking compression plate (LCP) fixation also has a tendency to become a matter of screw cut out or loss of fixation. The author reports on successful treatment of two osteoporotic proximal humeral fractures combined with medial meta-physeal comminution, with application of additional direct medial supporting plate fixation. Medial plate fixations were added when the fractures were still unstable after the conventional lateral LCP fixation and anterior circumflex humeral arteries had been ruptured before. The fixations were stable enough to start exercise immediately after surgery. The inclinations of the humeral neck were not changed until the last follow-up and clinical results were satisfactory without humeral head osteonecrosis which was a concern.