Risk factors for intra-articular involvement in proximal humeral fractures

Introduction: Identification of intra-articular involvement in proximal humeral fractures is important for operative decision making. The aim of this study was to identify the risk factors associated with intra-articular involvement in proximal humeral fractures. 

Materials and methods: One hundred consecutive three-dimensional computed tomography reconstructions of proximal humeral fractures were identified. The fracture lines were then accurately transcribed onto a two-dimensional superior view of the humeral head and each fracture was assessed for intra-articular involvement. Statistical analyses were undertaken to identify risk factors for intra-articular involvement and extent of involvement. Furthermore, for each risk factor, common fracture patterns were identified and compared to anatomical landmarks.

Results: Overall, 58% of the fractures involved the articular surface. High-energy mechanism, female gender, age ≥ 65, and posterior dislocation were risk factors for intra-articular involvement. Low-energy mechanism, female gender, age ≥ 65, varus angulation, and posterior dislocation were risk factors for increased extension of the fracture onto the articular surface.

Conclusion: Intra-articular involvement in proximal humeral fractures is influenced by demographics and fracture characteristics (mechanism of injury, angulation, and dislocation). Patients with identified risk factors should be appropriately evaluated for intra-articular fractures during preoperative planning to assist in operative decision making. Level of evidence: Basic science; anatomy study.