Vitamin D status in healing of distal humeral fractures: Clinical observations.

Background: Fracture healing is a complex biological process that begins soon after a fracture has occurred. Whereas the role of vitamin D status on the maintenance of bone health is well established, the clinical effects of vitamin D deficiency in the healing of distal humeral fractures are less well explored. This study examines the role of vitamin D serum levels in distal humeral fractures (C2, C3) managed with open reduction and double plate fixation, by comparing its concentration in patients with or without radiographic signs of fracture healing and in control subjects. Our hypothesis is that 6 months from treatment vitamin D levels will be different between the groups of patients.

Material and methods: We measured the vitamin D serum level in a cohort of consecutive adult patients aged 30 to 60 years. They included a group of subjects without fractures who were admitted to our clinic in the 6 months preceding the study (controls) and two groups of patients with humeral fractures who at 6-month follow-up showed or failed to show radiological signs of fracture healing.

Results: The mean vitamin D concentration was 23.03 μg/L (±5.8) in the group with radiographic signs of fracture healing, 9.30 μg/L (±2.60) in the group with radiographic signs of delayed union and 26.15 μg/L (±11.76 μg/L) in the control group. Significantly different (p < 0.05) concentrations were measured between the fracture groups, between the group with radiographic signs of fracture healing and the control group and between the group with radiographic signs of delayed union and the control group.

Discussion: Vitamin D is primarily involved in the stages of hard callus formation and remodelling. It also has several functions that affect the early stages of fracture healing. Vitamin D influences the cellular process of bone healing, although the underlying mechanism is still partly unclear. It would be useful to determine the vitamin D status of fracture patients at admission and to start supplementation, with periodic checks, to foster the consolidation phase. Although vitamin D is clearly not the only factor influencing the consolidation of a surgically treated distal humerus fracture, its concentration can easily be determined and managed. Our data suggest that vitamin D levels should be determined at admission and that fracture patients with low concentrations should be started on vitamin D supplementation.