There is a possibility of displacement 40 days after humeral surgery, but the probability is relatively low, and generally the fracture ends are initially stabilized at this stage.
Patients with humerus fractures may still be displaced 40 days after surgery, for example, if full weight-bearing activities are performed early, if the internal fixation is removed early for various reasons, or if the humerus is subjected to a second external force that causes a secondary fracture.
Although there is still a possibility of displacement 40 days after humerus surgery, the probability is relatively low, and the vast majority of patients will not be displaced, because at around 40 days there is already a primitive bone scab, which can be connected to the fracture ends through the fibrous connective tissue, so the fracture ends already have initial stability.
If there is severe pain and swelling in the affected limb 40 days after humerus surgery, you should go to the hospital in time for treatment.