Intravenous Bisphosphonate in Stress Fracture Treatment -A Randomised Controlled Double Blinded Multicenter Trial

Inclusion Criteria: * Age 18-70 years * Stress fractures in the foot. A stress fracture is defined as a fracture occured after repetitive trauma, with characteristic MRI findings (ref) and distinctive pain over the fracture site at weight bearing. * at least 6 months of pain history * compliant patient * non-aided ambulatory patient prior to the injury Exclusion Criteria: * Ongoing use of bisphosphonates, PTH/PTH-analogues or use within 12 months prior to the injury * Use of bisphophonates for more than 6 months within the last 5 years * Intolerance to zoledronic acid * Renal failure (GFR\<30) * S-25(OH)vitD \> 25 * pregnancy * breast feeding * hypocalcemia * MRI contraindications