Anti-osteoporosis therapy and fracture healing.

BACKGROUND: A number of medications are approved for treatment of osteoporosis. As mode of action usually is anti-catabolic/anti-resorptive or anabolic, it is of interest to know whether these drugs affect not only normal bone remodeling, but also fracture healing. OBJECTIVE: The purpose of this paper is to give a short overview of the potential effect of various anti-osteoporotic medication on fracture healing. METHODS: A narrative literature review was performed to describe the current knowledge. RESULTS: Anti-catabolic/anti-resorptive drugs: for bisphosphonates, the most common class of drugs in this group, experimental studies have shown a larger and stronger callus and delayed remodeling but no evidence of delayed healing. A human monoclonal antibody to RANKL is another anti-catabolic drug, with the only report to date showing enhanced healing in an animal model. Strontium ranelate is a drug where both anti-catabolic and a weak anabolic effect have been proposed, with experimental data ranging from no effect to significant increase in both callus volume and strength. Anabolic drugs: PTH has demonstrated accelerated healing of various experimental fractures and of distal radius and pelvic fractures in humans. While the exact mechanism is not fully understood, PTH results in increased recruitment and differentiation of chondrocytes and enhancement of endochondral ossification. A monoclonal antibody to block sclerostin is another potential anabolic pathway, where animal data have shown increase in bone mass and strength. The potential effect on fracture healing is yet to be studied. CONCLUSION: There are still large gaps in the understanding of the potential effect of anti-osteoporotic drugs on fracture healing, although based on present knowledge a recent or present fracture should not be considered as a contraindication to such treatment.