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Lower bone strength in young patients with Fontan circulation compared to controls
Anna Wikner1, Karna Johansson1, Elin Enocson1
1Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
Insights
Young patients with Fontan circulation exhibit reduced tibial bone strength, particularly in adolescents. This indicates potential age-related bone strength decline in individuals with Fontan circulation, highlighting a critical area for further research and intervention.
Area of Science:
- Pediatric Cardiology
- Biomedical Engineering
- Orthopedics
Background:
- Previous studies suggest bone deficits in patients with Fontan circulation.
- The impact of Fontan circulation on bone strength and its developmental trajectory remains unclear.
Purpose of the Study:
- To compare tibial bone strength-strain index between young patients (6-19 years) with Fontan circulation and age-/sex-matched controls.
- To investigate age-specific differences in bone strength within pediatric and adolescent subgroups.
Main Methods:
- Peripheral quantitative CT was used to examine the tibia in 20 patients with Fontan circulation and 20 controls.
- Bone strength-strain index was calculated in lateral and anterior-posterior directions.
Main Results:
- Patients with Fontan circulation had a significantly lower lateral strength-strain index compared to controls (p=0.043).
- Adolescents (13-19 years) with Fontan circulation showed significantly lower strength-strain indexes in both lateral and anterior-posterior directions compared to controls (p<0.001 and p=0.004, respectively).
- No significant differences were observed in the younger children's subgroup (6-12 years).
Conclusions:
- Young patients (6-19 years) with Fontan circulation demonstrate reduced tibial bone strength-strain index compared to controls.
- The observed bone strength deficits are primarily driven by adolescents, suggesting a potential age-related decline in bone strength in this population.
- These findings underscore the importance of monitoring bone health in adolescents with Fontan circulation.
Objectives:
Previous reports indicate bone deficits in patients with Fontan circulation. However, the consequences of these deficits on bone strength and when these changes occur are unclear.
Aim:
To compare the tibial bone strength-strain index between young patients (6-19 years) with Fontan circulation and age- and sex-matched controls, and to determine strength-strain-index in subgroups of children (6-12 years) and adolescents (13-19 years) versus controls.
Method:
The tibia was examined with peripheral quantitative CT. Based on the assessed data, bone strength-strain index was calculated in the lateral and anterior-posterior directions.
Results:
Twenty patients with Fontan and twenty controls (mean age 13.0 ± 4.4 years; 50% females) were examined. Patients had a lower strength-strain index in the lateral direction compared to controls (808.4 ± 416.8mm3 versus 1162.5 ± 552.1mm3, p = 0.043). Subgroup analyses showed no differences regarding strength-strain index in children (6-12 years) with Fontan circulation compared to controls. However, the adolescents (13-19 years) with Fontan circulation had lower strength-strain indexes in both the lateral and anterior-posterior directions compared to controls (1041.4 ± 299.8mm3 versus 1596.4 ± 239.6mm3, p < 0.001, and 771.7 ± 192.4mm3 versus 1084.9 ± 215.0mm3, p = 0.004). When adjusted for height, there were differences between patients (6-19 years) and controls in strength-strain indexes in both the lateral and anterior-posterior directions. In subgroup analyses, the results remained robust.
Conclusion:
Young patients (6-19 years) with Fontan circulation have a lower strength-strain index in the tibia compared to controls. Subgroup analyses show that this deficit is mainly driven by the differences in adolescents (13-19 years), which might suggest that bone strength decreases with age.
