(HealthDay News) – For adolescents with leg or ankle fractures, wearing a cast results in loss of bone mineral density in the hip or lower limb, according to a study published in the Feb. 1 issue of The Journal of Bone & Joint Surgery.
Dimitri Ceroni, M.D., of the University Hospitals of Geneva in Switzerland, and associates used dual X-ray absorptiometry scans of the total body, lumbar spine, hip, leg, and calcaneus to calculate bone mineral density before and after cast immobilization for 50 adolescents with leg or ankle fractures. Participants were matched with healthy controls and values were compared between the groups.
The researchers found no observed differences in bone mineral density or content between the injured and control group at the time of fracture. In the injured group, bone mineral parameters were significantly lower on the injured side at cast removal, with differences ranging from −5.8% to −31.7% for bone mineral density, and from −5.2% to −19.4% for bone mineral content. Compared with healthy controls, the injured adolescents had a significant decrease in bone mineral density at the hip, greater trochanter, calcaneus, and total lower limb during the cast period.
“Osteopenia does develop in the injured limb during cast immobilization for fracture treatment,” the authors write. “Further investigation is required to determine if the bone mineral mass will return to normal or if a permanent decrease is to be expected, which may constitute a hypothetical risk of sustaining a second fracture.”