Fractures may occur in compliant patients even while on active treatment. Inadequate responders are patients with an incident fracture (incident fractures) and a significant decrease in bone mineral density (BMD) or patients with a significant decrease in BMD and insufficient change in the relevant bone remodeling marker after at least one year of treatment.
Atypical, poorly healing fractures associated with long-term antiresorptive therapy, particularly minimal trauma fracture of the femoral shaft, at a given BMD can be considered a treatment failure.