Evaluation of bone density in infancy and adolescence. Review of medical literature and personal experience.

The evolution of medical and surgical therapies allows the increased survival rate of a growing number of children affected by rare pathologies. In this light osteoporotic disease is also of orthopaedic interest as it is sometimes the outward manifestation of serious pathologies (i.e. osteogenesis imperfecta). Sometimes, even in infancy and adolescence, osteoporosis is associated with complications due to fractures; in other cases it seems to have no immediate consequence. Nevertheless it must be considered as a fracture risk factor in adulthood as it negatively affects the achievement of peak bone mass. The evaluation of variations in bone mass that take place during growth is thus of particular importance in order to guarantee a level of bone health suitable for the next phase. These remarks compose the premise of a study on bone resistance carried out on a study population of between 6 and 18 years of age in the city of Pavia. To determine the resistance of the bone an ultrasound device was employed (Omnisense™ , Sunlight Medical Ltd, Tel Aviv, Israel) in two skeletal sites, distal radius and midshaft of tibia. The analysis of our results and a review of the relevant literature indicate that the median values of normality, against which we compare the measurements of the patients under examination, depend not only on age, sex, skeletal sites, race, and even ethnic group. The introduction of this new parameter, to be kept in mind when interpreting the results, invites us to be very prudent in determining the diagnostic threshold values in paediatric age. As with anthropometric data (weight, height, cranial circumference) it is possible to suggest an interpretation of the patient's SOS values comparing them with the 'centile curves' typical to the region the child belongs to. Of course, further studies are required to understand what are the variables involved and to determine the extension of the geographical area to be examined to obtain suitable reference curves.