When is a Fracture Not a Fracture?

Professor Mark R. Forwood1

1Griffith University, Gold Coast, Australia

When it’s a stress fracture (SFx)! SFx account for 1-7% of all athletic injuries, and underlie atypical femoral fractures (AFF) following long-term antiresorptive therapy. Repetitive loading of rat forearm creates highly reproducible ulnar SFx, with a histological appearance remarkably similar to biopsies from AFF. Our studies of SFx healing revealed that periosteal woven bone stabilises the SFx site, while BMU-based remodelling repairs the SFx line, a pathophysiology quite distinct from osteoporotic fracture. Bisphosphonates (BPs) inhibit bone remodelling, and daily treatment with risedronate caused a dose-dependent decrease in all phases of remodelling in our model, partly explaining the progression of SFx to atypical femoral fracture. We hypothesized that intermittent treatment with parathyroid hormone (iPTH) could activate remodelling in the presence of a bisphosphonate, accelerating SFx healing. Our data rejected that hypothesis, confirming clinical observations that anabolic iPTH was blunted by concurrent bisphosphonate treatment, but effectively accelerated healing upon cessation of the bisphosphonate. This is important knowledge to inform treatment for athletes with poorly healing SFx and patients with early signs of atypical femoral SFx. The goal here would be to activate remodelling and healing of the SFx. Patients with a complete AFF present similarly to those with typical femur, or osteoporotic, fractures and must be managed operatively.


Professor Forwood was appointed by invitation as the Foundation Chair of Anatomy at Griffith University in 2009, and Head, School of Medical Science in 2013. His research has contributed to understanding the biology of skeletal adaptation, stress fracture repair and bone tissue quality in osteoarthritis, osteoporosis and tissue banking. He was a NHMRC Fellow at Indiana University Medical Centre from 1991-1994 with David Burr and Charles Turner, following which he returned to UQ, where he continued research in skeletal biology and taught gross and musculoskeletal anatomy. Prof Forwood’s research has been continuously funded by NHMRC since 1996. He is a member of Council of the Australian and New Zealand Bone and Mineral Society and the Board of Directors of the International Federation of Musculoskeletal Research Societies. He is also  an Editorial Board member of Bone (Elsevier) and a section editor for Current Osteoporosis Reports (Springer). In 2016, Prof Forwood was elected as a Fellow of the Queensland Academy of Arts and Sciences.