The humeral head is mostly cancellous bone wrapped in cartilage, and in elderly fracture patients that cancellous stock is thin. Holding a reduced head fragment means placing support directly under the joint surface — and doing it gently, because aggressive threads in soft subchondral bone can cut channels that loosen the whole construct.
The smooth locking peg answers that requirement. Locked rigidly to the plate at a fixed angle, the peg advances into the head without cutting threads and acts as a strut beneath the articular surface, sharing load across a broad contact area. The plate itself follows the lateral metaphysis, with lengths for fracture lines that run into the shaft. Fragment reduction, peg placement and plate length remain decisions for the operating surgeon.
