Role of bone densitometry as a diagnostic and monitoring tool in complex regional pain syndrome: report of a case

Abstract

Complex regional pain syndrome (CRPS) is a rare pathology, characterized by chronic pain and local changes of the affected site. It occurs after trauma or, less frequently, without a clear trigger. The diagnosis is made clinically, evaluating the presence of typical findings detailed in the Budapest criteria, such as continuous and disproportionate pain, and typical signs and symptoms, like edema, thermal asymmetry, and decreased range of motion. Imaging studies, such as radiography, magnetic resonance imaging, or 3-phase bone scintigraphy also provide valuable information, especially in cases that present with more doubts, and to make a differential diagnosis with other pathologies. In this regard, the measurement of bone mineral density by dual X-ray absorptiometry (DXA) is also a useful tool, not only in the diagnostic phase, by showing the greater demineralization of the affected limb, but also in the evaluation of the therapeutic response to bisphosphonates. We present the case of a patient with CRPS of the lower limb, where bone densitometry was very useful in her clinical management.