A RADIOLOGICAL INVESTIGATION OF KNEE OSTEOARTHRITIS

Abstract

The task of evaluating tissue parameters in and around the knee joint in those with and without knee osteoarthritis was taken upon in this thesis. One knee X-ray, a Dual X-ray Absorptiometry scan of the lumbar spine, hip, distal femur and proximal tibia and an MRI scan of the knee were acquired from 120 healthy and 55 osteoarthritic participants 20 to 83 years of age. Scans were analyzed to yield outcome parameters of minimum joint space width (mJSW), bone mineral density (BMD) and cartilage volume and thickness using dedicated software algorithms. All osteoarthritic individuals completed WOMAC and SF-36 questionnaires. Joint space analyses revealed that healthy males have larger values than females of similar ages and that increasing disease severity is reflected by joint space narrowing. Data suggests there may be a threshold mJSW value for both males and females at which point one could be identified with early knee OA. Radiographic measures were also found to correlate with symptoms of pain (in females) and physical function. Cartilage volume and thickness analyses generally paralleled those of mJSW. Measurements appeared constant throughout the ages in healthy males while a small decline in parameters was apparent in healthy females. Increasing disease severity, body mass index and age were also significantly related to joint space narrowing. Cartilage volume and thickness were significantly correlated with pain, stiffness and physical function in those with knee OA. iv In healthy and osteoarthritic individuals, BMD measurements in the distal femur and proximal tibia were higher in males than females but were not significantly different in those with knee OA versus those without. Disease severity was found to be positively correlated with subchondral BMD in the distal femur and the proximal tibia suggesting that those with more severe disease may have more sclerotic bone compared to those with milder disease.