There is an increased prevalence of backbone or "vertebral" fractures in children with arthritis and other "chronic rheumatic diseases," according to Canadian researchers.

"Our study has demonstrated that vertebral fractures are not an uncommon sequelae among this high-risk population," lead investigator Dr. Meranda Nakhla told Reuters Health.

These children are known to be at risk for having abnormally low bone mass — a condition called osteopenia that could progress to the brittle-bone disease osteoporosis.

In the Journal of Pediatrics, Nakhla, of Montreal Children's Hospital, and colleagues report that they studied 90 patients (22 boys and 68 girls) attending the rheumatology clinic at that institution. The children had conditions including juvenile idiopathic arthritis and various types of connective tissue disease.

In all, 10 boys and 7 girls (19 percent) were found to have a total of 50 vertebral fractures, giving an average of 2.9 per affected child, which is much higher than that found in the general population.

"Significant predictors" of backbone fractures were male sex, increased body weight, and high cumulative dose of steroid drugs used to treat their illness.

Nakhla also noted that 44 percent of children backbone fractures had no outward symptoms. Therefore, "our study findings raise the issue of whether children with rheumatic diseases should be regularly screened for fractures," Nakhla said.