Bone mineral density in pediatric Marfan syndrome patients with scoliosis: a retrospective case-control study using hounsfield units

Bone mineral density (BMD) in pediatric Marfan syndrome (MFS) patients remains debated. While dual X-ray absorptiometry for BMD assessment is gold standard, it is unreliable in scoliosis. Hounsfield Units (HU) measurement from lumbar CT scans in pediatric patients is increasingly used. The aim of this study is to evaluate BMD in patients with MFS by comparing HU values with those of adolescent idiopathic scoliosis (AIS) patients scheduled for spinal correction surgery. Propensity score matching (1:2, ages 10–19) was performed between MFS and AIS patients based on age, sex, body mass index (BMI), and spinal deformity severity. HU values were measured at L1, L3, and L5 on middle axial CT images using reconstruction software, excluding posterior vertebral body radiolucency. Medication histories were recorded. From 33 MFS and 209 AIS patients undergoing posterior fusion (2007–2024), 31 MFS patients were matched 1:2 with 62 AIS controls. One MFS patient had used progesterone before CT. HU values were significantly lower in MFS than AIS at each vertebra; average HU was 168.7 vs. 214.0 (P < 0.001). In MFS patients, low HU values were associated with low BMI, large Cobb angle, and prior angiotensin receptor blocker use. No patients in either group received vitamin D or other bone-related treatments. While routine CT is discouraged to minimize radiation, utilizing existing preoperative data for opportunistic bone screening may be considered for pediatric MFS patients, given the high prevalence of values below the osteoporotic threshold.