The Spine in β-Thalassemia Syndromes

In Brief Study Design. Literature review. Objective. To present a comprehensive overview of spinal involvement in patients with β-thalassemia, aiming to orient the spinal surgeon to these potentially disabling complications. Summary of Background Data. β-thalassemia, an inherited disorder of hemoglobin synthesis, is the most common monogenetic disease worldwide. Patients with thalassemia major (TM) suffer a severe anemia that requires regular blood transfusions for survival and iron chelation therapy to control transfusional iron overload. Thalassemia intermedia is a phenotype of thalassemia with a milder course and anemia, wherein most patients remain transfusion independent. Spinal involvement related to disease course and treatment is common in patients with thalassemia syndromes, yet it has not been constructively reviewed in the literature. Methods. Potentially relevant studies were identified from an electronic search of MEDLINE (1966 to the second week of May 2010). Results. In patients with TM, genetic and acquired risk factors lead to osteoporosis, pathologic fractures of the spine, and back pain. Osteoporosis in TM patients is progressive; thus, early diagnosis and treatment are recommended. Bisphosphonates are relatively safe and effective in this patient population. Characteristic intervertebral disc degeneration is also seen in patients with TM who have evidence of severe iron overload or those who receive the subcutaneous iron chelator deferoxamine. Spinal asymmetry and overt scoliosis are common in patients with TM. The prognosis seems favorable, with many patients showing spontaneous resolution without the need for intervention. In patients with thalassemia intermedia, ineffective erythropoiesis drives extramedullary hematopoietic tissue formation, which is mostly evident on magnetic resonance imaging. Paraspinal involvement is of greatest concern because of the associated spinal cord compression. Several treatment options have been described, including transfusion therapy, laminectomy, radiotherapy, and the use of fetal hemoglobin-inducing agents that decrease the hematopoietic drive. Conclusion. Current knowledge supports that spinal involvement in patients with β-thalassemia is common and diverse yet still requires further prospective evaluation. Osteoporosis, pathologic fractures of the spine, and back pain are common in β-thalassemia patients. Characteristic intervertebral disc degeneration is attributed to iron overload and chelation. Spinal asymmetry and overt scoliosis may occur but carry a mild course. Paraspinal tissue formation due to compensatory hematopoiesis foci is common in nontransfused patients and remains worrisome.