ObjectiveTo analyze the effectiveness of proximal humeral internal locking system (Philos) plate for proximal humerus fracture. MethodsThirty-three patients with proximal humerus fracture were treated with open reduction and internal fixation with Philos plate between January 2009 and January 2014. There were 19 males and 14 females, aged 23-89 years (mean, 56.6 years). The left side was involved in 15 cases, and the right side in 18 cases. The injury causes included falling in 20 cases and traffic accident in 13 cases. All cases received X-ray and CT scan and three-dimensional reconstruction before operation. According to the Neer classification, 8 cases were rated as two-part fractures, 15 cases as three-part fractures, and 10 cases as four-part fractures. The interval time between injury and surgery was 1-7 days (mean, 3.67 days). Postoperative functional outcome was evaluated using the Constant-Murley score. ResultsInfection and liquefaction occurred in 2 cases respectively, which was cured after corresponding treatment; primary healing of wound was obtained in the other 29 cases. Five patients had shoulder pain. The patients were followed up 11-47 months (mean, 33 months). The mean time of fracture union was 7.5 months (range, 5-9 months) on the X-ray films. Humeral head necrosis occurred in 2 patients with Neer four-part fractures, and internal fixation failure occurred in 3 patients (2 screw broken and 1 plate broken) with four-part fractures (2 cases) and three-part fractures (1 case), which was cured after conservative treatment. At last follow-up, the mean Constant-Murley score was 70.5 (range, 42-90); the results were excellent in 3 cases, good in 21 cases, moderate in 6 cases, and poor in 3 cases. ConclusionSatisfactory results can be expected for proximal humeral fracture by using of the proximal humeral internal locking system plate based on strict indication and early rehabilitation training.