Stable fixation of unstable proximal humerus fractures until bony consolidation. Early mobilization of the shoulder and early active rehabilitation program to ensure a good functional outcome and a good restoration of the activities of daily living. Unstable two-, three- and four-part fractures of the proximal humerus (classified according to the AO classification as: 11-A2, A3, B1, B2, B3, C1, C2, C3). Nonunions of the proximal humerus, especially at the neck. Pathologic fractures of the proximal humerus. Comminuted humeral head fractures in old patients, which cannot be reconstructed adequately. Proximal humerus fractures in the immature patient. Local infection after previous surgery. Deltopectoral approach. Blunt mobilization of the deltoid muscle. Suture loops through the supraspinatus tendon, the infraspinatus tendon, and the subscapularis tendon close to their bony insertion. Careful indirect reduction of the fracture fragments without further damage to their blood supply. Correct positioning of the LPHP (Locking Proximal Humerus Plate) on the lateral side of the humerus, approximately 5 mm below the tip of the greater tuberosity. Indirect approximation of the subcapital fracture component to the plate, by tightening a standard 3.5-mm cortical bone screw inserted into the first hole distal to the metaphyseal fracture line. Temporary fixation of the plate with 1.8-mm Kirschner wires. Fixed-angle fixation of the plate to the bone, using locking screws. Additional stabilization of the tuberosities to the plate with suture loops. Between January 1, 1997 and April 30, 2002, 64 patients with acute fractures of the proximal humerus were treated with fixed-angle plating at the UKH Graz. 36 patients meeting the inclusion criteria (that is primary operative stabilization within 14 days after trauma in a standardized way and minimal follow-up period of 12 months) were assessed 31 months after surgery on average, using the Constant Score and the DASH Score. The mean age of the 22 women and 14 men was 57.5 years (21-78 years). According to the AO classification eight fractures were classified as 11-A3, one fracture as B1, five fractures as B2, three fractures as B3, one fracture as C1, 16 fractures as C2, and two fractures as C3. A mean Constant Score of 62.6 points and an age-related Constant Score of 80.7% on average, as well as a DASH Score of 18.0 points were obtained, constituting a satisfactory result in three quarters of all patients. Complications observed were two humeral head necroses, one partial necrosis after a head-splitting fracture with nevertheless good clinical result, and a deep infection in two cases. Breakage of the plate was seen in one patient with an A3.3 fracture without medial buttress; no further surgery was necessary; the fracture healed after a short period of immobilization.