Definitions, pathogenesis, and pharmacological options for bone marrow lesions: an updated review

Abstract

The term “Bone Marrow Lesions” (BMLs) identifies a pathological state characterized by a structural degeneration of the osteochondral unit (OCU) and by an alteration of the biochemical balance existing between articular cartilage and subchondral bone. These lesions, if they do not resolve spontaneously and if not adequately treated, can give rise to chronic degenerative diseases such as osteoarthritis and, in the most serious cases, evolve into stress fractures. The technique considered to be the gold standard for the detection of BMLs is Magnetic Resonance Imaging (MRI), to which BMLs appear as an area of ill-defined hyperintensity (high signal) in subchondral bone in fat-suppressed T2-weighted sequences, and hypointense areas (low signal) in T1-weighted sequences. There are several pharmacological intervention strategies for the treatment of BMLs, primarily the administration of bisphosphonates, but in recent years Iloprost treatment is also proving to be an effective therapeutic strategy. The aim of this review is to provide further evidence on the sequence of clinical-biological events leading to the appearance of these lesions, and on the current treatment strategies with the best outcome, in order to shed light on the importance of conducting further research in this field, since BMLs are part of a pathological picture characterised by numerous variables.