Intermittent Parathyroid Hormone Accelerates Stress Fracture Healing More Effectively Following Cessation of Bisphosphonate Treatment.

Parathyroid hormone (PTH) and bisphosphonates (BPs), including alendronate (ALN), have opposing effects on bone dynamics. The extent to which PTH remains effective in the treatment of stress fracture (SFx) in the presence of an ongoing BP treatment has not been tested. SFx was induced in 150 female Wistar rats, divided into five equal groups ( = 30).

Single injection of PTH improves osteoclastic parameters of remodeling at a stress fracture site in rats.

Stress fractures (SFx) result from repetitive cyclical loading of bone. They are frequent athletic injuries and underlie atypical femoral fractures following long-term bisphosphonate (BP) therapy. We investigated the effect of a single PTH injection on the healing of SFx in the rat ulna.