Magnetic resonance imaging of the knee in chronic knee pain. A 2-year follow-up

Objective: The aim of the study was to evaluate the change over time of car tilage defects, subchondral lesions and meniscal abnormalities of the knee using magnetic resonance (MR) imaging with a 2-year interval in patients wi th chronic knee pain. Design: In the format of a prospective study of early osteoarthritis (OA), the signal knee (most painful at the inclusion in the study 1990) in 47 ind ividuals, 25 women and 22 men (aged 41-57 years, median 50), with chronic k nee pain, with or without radiographically determined knee OA, were examine d using MR imaging on a 1.0 T imager with a 2-year interval (median 25 mont hs, range 21-30). Cartilage defects, subchondral lesions and meniscal abnor malities were recorded and compared in blind between the examinations. Results: Five new cartilage defects and eight subchondral lesions appeared during the 2-year interval. Seven defects and seven subchondral lesions dis appeared during the same time. Thirty-two out of 93 cartilage defects (34%) and 19 out of 32 subchondral lesions (59%) displayed an increase or a decr ease in size over time. A meniscal abnormality appeared in three locations, and disappeared in none. In 14 out of 54 locations (26%) with a meniscal a bnormality an increase or a decrease of the abnormality was recorded over t ime and no abnormality decreased. Conclusions: After the 2 years of observation it was possible to register, using MR imaging, the appearance, increase, decrease and disappearance of c artilage defects, subchondral lesions and meniscal abnormalities in middle- aged people with chronic knee pain. This has to be considered in studies of the natural course of knee CA as well as in studies of the intraarticular effect of pharmacological treatment aiming at cartilage repair or protectio n. (C) 2001 OsteoArthritis Research Society International.