Fracture prediction by bone trait dis-integration using DXA among a clinical cohort of adults with cerebral palsy
Prepared by: AACPDM Digest reviewer/committee member Kathleen Friel, PhD
Keywords:
- Cerebral palsy
- DXA
- Bone mineral density
- Hip fracture
Study Type: Retrospective cohort study
Summary:
Adults with CP have a higher incidence of fractures than adults who do not have CP. A better understanding the factors that raise risk can drive the development of therapies that would reduce risk, and therefore enhance quality of life in this population. This study examined the association between bone trait dis-integration and risk of fractures in adults with CP (n=75) who received a hip dual-energy X-ray absorptiometry (DXA) scan between 01/01/2012–03/05/2021 at one medical center. Participants were followed through 09/12/2023 for fractures.
Bone mineral density (BMD), bone mineral content (BMC), and bone area were measured on each DXA scan. Measures were taken from the femoral neck of the hip. The study team focused on these measures alone, and in addition, on the interaction between bone size and mass. The integration or dis-integration of these measures may be of clinical importance to adults with CP and has not been adequately studied.
The primary outcome variable was the interaction term between BMC-area residual and bone area, from a sex-stratified multiple linear regression of bone area and BMC that adjusted for age and GMFCS group. Overall, 19 participants (25.3%) experienced a fracture during the study period, with a median follow-up duration of 0.8 years before the fracture occurred. As BMC-area residual decreased, the odds ratio of a fracture increased, but only for those with a smaller bone area.
Overall, the study emphasizes that adults with CP are at risk for fractures. This risk is more deeply understood by examining the differential effect on bone strength by key size-mass trait dis-integration patterns that are conditional on bone size. By assessing integration and dis-integration, future studies can identify key variables that increase risk of fractures in adults with CP. These findings would also pave the way for bone strengthening therapeutics for adults with CP and other individuals with neurodevelopmental disorders.