[Secondary prevention of osteoporosis and identification of high risk patients]

Low bone mass is a major determinant of bone fragility. With respect to hip fracture risk however, there is limited contribution of BMD to the exponential age-related increase in hip fracture incidence. Large prospective studies have identified a number of additional risk factors for hip fractures independent of bone density. These can be classified as skeletal factors and fall-related factors. Body height and hip axis length are positively correlated with fracture risk. Neuromuscular impairment with low gait speed, difficulty in doing a tandem walk, lower limb dysfunction, body sway or inability to rise from a chair without using one's arms predict future fracture risk. According to the concept of evidence-based medicine (EBM) preventive strategies are now available. Supplementation with calcium and vitamin D restores bone quality through suppression of secondary hyperparathyroidism and decreases the risk of falling through improvement of neuromuscular co-ordination and body sway. Treatment with the bisphosphonates alendronate and risedronate increase bone strength and result in a significant reduction of vertebral as well as non-vertebral fractures. Hip protectors absorb energy during a fall and reduce hip fracture risk by 56%. Risk factor based patient selection may improve the cost-effectiveness of therapy.