Five-year risk of fracture and subsequent fractures among adults with cerebral palsy

Background: Epidemiologic evidence documenting the incidence of fracture and subsequent fractures among adults with cerebral palsy (CP) is lacking, which could inform fracture prevention efforts. The objective was to characterize the 5-year rate of initial and subsequent fragility fractures among adults with CP. Methods: This retrospective cohort study used Medicare claims from 01/01/2008-12/31/2019 from adults >= 18 years old with CP (n = 44,239) and elderly >= 65 years old without CP (n = 2,176,463) as a comparison. The incidence rate (IR), IR ratio (IRR), and site distribution were estimated for the initial and subsequent fragility fractures over 5-years by sex and age. Results: The IR of fragility fracture at any site over the 5-year follow-up was similar for 18-30-year-old men with CP (IR = 5.2; 95%CI = 4.4-5.9) and 30-34-year-old women with CP (IR = 6.3; 95%CI = 5.3-7.2) compared to the same sex youngest-old (65-74 years old) without CP (IRR = 1.09 and 0.94, respectively, both P > 0.05), and increased with older age for those with CP. The number of fragility fractures and IR of subsequent fragility fractures was similar for young men and middle-aged women with CP compared to elderly without CP, and increased with older age for those with CP. The proportion of fragility fracture at the tibia/fibula decreased while the vertebral column and multiple simultaneous sites (most involved hip/lower extremities) increased with older age. Conclusion: Young and middle-aged adults with CP had similar-to-worse initial and subsequent fragility fracture profiles compared to the general elderly population- a well characterized group for bone fragility. Findings emphasize the need for fracture prevention efforts at younger ages for CP, possibly by similar to 5 decades younger.