Study of Bone Quality and Fracture Line Morphology of the Posterior Medial Humeral Calcar in Proximal Humeral Fractures

Abstract Objective: To investigate the relationship between fracture line morphology, bone quality and fracture morphology of the posterior medial humeral calcar in proximal humeral fractures METHODS: CT data of patients with proximal humeral fractures diagnosed in our hospital from 06/2019 to 06/2021 were retrospectively analyzed to describe the map and coordinate analysis of the posterior medial humeral calcar fracture based on three-dimensional reconstruction, to create varus, valgus and normal groups according to the inclination angle of the humeral head, and to measure the bone mass of the posterior medial humeral calcar and perform statistical analysis.RESULTS: Sixty-two patients met the inclusion criteria, aged 15 to 72 years, there were 21 varus, 24 valgus and 17 normal types. Epiphyseal extension occurred most frequently posteriorly and medially, with the fracture line ending mostly posterior to the greater tuberosity. The thickness of the varus was (2.33 ± 0.47), valgus was (2.59 ± 0.33) and normal type was (2.69 ± 0.53). The T-test showed that the thickness of the bone in the varus was less than the other two types, and bone density and pinch angle were no statistically significant.CONCLUSION: There is no correlation between the trend of the posterior medial fracture line of the humeral calcar, bone density and internal, external rotation of the humeral head. The medial bone thickness after varus is less than that of valgus and normal fractures. The fracture line endpoint is mostly located posterior to the greater tuberosity.