Age-specific occurrence of pathological fractures in patients with spina bifida

Pathological fractures (PFs) are common in patients with spina bifida. However, most previous studies refer to the overall fracture rate and largely neglecting putative age-dependent aspects. The aim of this retrospective study was to characterize patterns of fracture occurrence in childhood. In a retrospective study, we identified PF, all in the lower limbs, in 13% of 210 patients with spina bifida aperta. We further identified a bimodal frequency distribution of pathological fractures, with peaks at 1-5 and 10-12 years. We could thereby distinguish two groups of patients: (i) Children with a first fracture before an age of 6 years developed frequently multiple fractures within the following years, but fracture series typically stopped by 6 years-of-age. (ii) Children with a first fracture after the age of 6 years had fewer fractures, but these occurred also in adolescence. PF occurred rarely after the age of 13 years. The age at fracture correlated with the fracture site with 85% of the fractures occurring in the femur in the first five years of life and an increased frequency of tibia and foot fractures later in life. While, overall high lesion levels and preceding immobilizing events were risk factors for PF, femur fractures in children under 6 years-of-age occurred independent of their lesion level, and the age at verticalization did not correlate with PF rates.Conclusion: Based on these findings, standardized and effective preventive physiotherapeutic and/or pharmacological interventions to tackle PF in spina bifida need to consider age-specific differences in occurrence and reoccurrence of fractures.What is Known:• Pathological fractures are common in patients with spina bifida aperta, and associated risk factors include high lesion level, immobilization and low bone density.What is New:• We first report a bimodal frequency distribution of pathological fractures in childhood (first peak 1-5 years, second peak 10-12 years) and link early-onset fracture occurrence with the risk of multiple fractures arise in a short time period but a the chance of self-limitation of fracture series within a few years.• We show that femur fractures in children under 6 years-of-age occurred independent of their lesion level, and the age at verticalization did not correlate with PF rates.• We further link the age-dependent occurrence pattern with the risk of further fractures and with the chance of self-limitation of fracture series. The earlier a first fracture occurs, the more probable multiple fractures arise in a short time period. Nevertheless, early fracture series are often self-limiting within a few years.• Femur fractures in children under 6 years-of-age occurred independent of their lesion level, and the age at verticalization did not correlate with PF rates.• Based on these findings, physiotherapeutic and/or pharmaceutical concepts need to be developed in an age-adapted manner and in consideration of the potential self-limiting nature of fracture series.