A fragility fracture is a fracture which happens from minor trauma. A stress fracture happens from repeated normal daily activities, like walking or going up or down stairs. This is a fracture from no trauma.
Bone must be at very high risk of fracture to develope a stress fracture. Clinical Osteoporosis was defined by NIH in 2001 as increased risk of fracture. Therefore, a Stress Fracture is defined as Clinical Osteoporosis.
Stress fracture does not necessarily mean low Bone Mineral Density (BMD). A person can have “normal” BMD on DXA testing and still have Clinical Osteoporosis. Fracture risk does not depend solely on BMD. Remember FRAX. Stress fractures can occur when bone is too thick, has a lot of mineral (high BMD), and is too rigid, too stiff, and too brittle.
The key to healing a stress fracture is to decrease weight bearing. That means crutches or a walker. “Canadian” crutches are far easier to manage and avoid sore armpits. Immobilization is usually not necessary as long as weight bearing is decreased.
A Stress Fracture makes the diagnosis Clinical Osteoporosis. Therefore a full Bone Health work-up is needed, including VFA and lab tests. Common findings include: low 25-hydroxy Vitamin D, Secondary HyperParathyroidism, inadequate Calcium intake, Smoking, Alcohol intake more than 2 drinks daily, body weight below BMI of 19, and poor diet / low protein nutrition.
Jay Ginther, MD