Is immobility the principle cause of osteopenia and pathologic fractures in non-ambulatory cerebral palsy patients?

Fractures without significant trauma are not uncommon in osteopenic children who have non-ambulatory cerebral palsy (NACP). The aim of our investigation was to identity factors other than immobility which may contribute to the occurrence of these fractures. We reviewed the charts of 16 children with NACP who are followed at the Children's Clinic for Rehabilitative Services in Tucson, Arizona. All are nutritionally dependent on commercial formulas administered through gastrostomy tube. The quantity of formula ingested was determined by their physicians and nutritionists, was administered by their caregivers and was based on weight changes observed in these patients over time. Caloric intake in 11 of the 16 children was less than 50% of the RDA based on weight and age and in 15 of the 16 was less than 75% of the RDA. Of the 16 children, 9 received less than 75% of the RDA for calcium, 11 received less than 75% of the RDA for phosphorous, and 10 received less than 75% of the RDA for vitamin D. In one of the two children who suffered multiple fractures the RDA intakes for calcium, phosphorous and vitamin D intakes were respectfully 45%, 45% and 54% and in the other child were 78%, 75% and 46%. Our results document these as well as other micronutrient deficiencies. The non-ambulatory, tube-fed child with cerebral palsy has lower caloric needs and if given un-supplemented standard commercial formulas receives a suboptimal intake of micronutrients which places the child at risk for attendant complications. The data suggest that osteopenia and non-traumatic fractures may be attributed, at least in part, to inadequate intake of crucial vitamins and minerals. Further studies are necessary to validate our observations and define optimal calcium and other micronutrient supplementation in this population.