Features of Three- and Four-Part Proximal Humeral Fractures and Outcome of Internal Fixation Using the Philos® Locking Plate

Background: Proximal humeral fractures are among common types of fractures and remain a challenging issue for surgical management. This study aimed to assess the clinical outcomes and complication rates of three- vs. four-part proximal humeral fractures, treated with internal fixation using the Philos® plate.Material and Methods: In this cohort study, a total of 30 consecutive patients with three-part or four-part proximal humeral fractures based on the Neer classification were included. Surgical treatment was performed with open reduction and internal fixation using the Philos® plate. The constant score was evaluated 6 months later in follow-up. The P<0.05 was considered significant.Results: Four-part fractures were mainly caused by trauma from above, while insults of opposite direction were responsible for more than half of 3 part fractures (P=0.01). Open fractures were only observed in patients with a four-part fracture (P=0.018). No significant differences were noticed regarding gender, cause, and side of the fracture.The presence of other fractures, fracture of the implant, reduction loss, avascular necrosis (AVN) of humerus head, rotator cuff injury, and revision surgery were significantly higher in patients with four-part fractures.The mean constant score was 81.40±11.61 and 65.09±16.09 for three-part and four-part fractures, respectively (P=0.006).Conclusion: Open reduction and internal fixation with Philos® plate yield acceptable results in both types of fractures, however, the prognosis of this intervention is poorer four-part fractures