Bone marrow lesions in the knee: the clinical conundrum.

Osteoarthritis (OA) of the knee is a common, debilitating condition. Twelve percent of people aged 60 years or older have symptomatic knee OA. With increasing global incidence of obesity, the prevalence of OA is set to dramatically rise Cartilage deterioration is a hallmark of the disease, but other areas are equally as important, such as changes to the subchondral bone. Magnetic resonance imaging (MRI) has enabled us to view bone marrow lesions (BMLs) in the subchondral bone, allowing progress to be made in understanding their natural history, effect on pain, structural deterioration and other factors. The focus of this review is to try to put a new clinical perspective for the patients with BMLs in relation to pain, functional decline and prognosis.