Bone Abstracts

Background: Bone involvement in patients with β-thalassemia is well known, but only few studies have analyzed bone microarchitecture and the prevalence of intervertebral disc calcifications (IDCs) in these patients. The aim of our study was to evaluate the bone quality in a group of patients with β-thalassemia in terms of geometry and microarchitecture properties; moreover, we evaluated the presence of IDCs in these patients.

Material and methods: Our retrospective case–control study was conducted in adults with β-thalassemia (aged 18–50 years). Patients were divided, according with the ISCD, into 2 groups: subjects with BMD Zs ≤−2.0, below the expected range for age, and subjects with BMD Zs >−2.0, within the expected range for age. Assessment of proximal femur geometry was performed using the Hip Structural Analysis (HSA), providing the following parameters: Hip Axis Length (HAL), Femoral Strength Index (FSI), Cross-Sectional Moment of Inertia (CSMI), Cross-Sectional Area (CSA), Section Modulus (Z), and buckling ratio (BR). Assessment of bone quality was performed using the Trabecular Bone Score (TBS), stratifying subjects into 3 groups: with abnormal (TBS ≤1.200), partially altered (TBS >1.200 and <1.350), and normal (TBS ≧1.350) trabecular microarchitecture. Finally, we evaluated the prevalence of IDCs highlighted by images of Vertebral Fracture Assessment.

Results: We evaluated 49 patients with β-thalassemia, mean aged 35.2±9.6 years, divided into two groups: 25 patients with Zs ≤−2.0 and 24 patients with Zs >−2.0. There was a statistically significant difference between groups in number of fragility fractures (P=0.0339). Furthermore, TBS of patients with Zs ≤−2.0 was significantly lower than individuals Zs >−2.0 as mean value (P=0.0006) and as categorized value (P=0.0061). Finally, we evidenced in seven patients (14.29%) the presence of at least one IDC.

Conclusions: Our results showed that β-thalassemia is characterized not only by a reduction in BMD, but also by a geometric and qualitative bone microarchitecture involvement, demonstrated that HSA and TBS should be included in the assessment of these subjects, in order to obtain a proper management and prevention of fragility fractures; furthermore, presence of IDCs might be better investigated.