Purpose:To prospectively evaluate the association between clinical features and structural abnormalities found at magnetic resonance (MR) imaging in patients with osteoarthritis (OA) of the knee. Materials and Methods:The study was approved by the institutional medical ethics review board.

This pilot study presents a technique for three-dimensional and quantitative analysis of meniscus shape, position, and signal intensity and compares results in knees with (n 5 20) and without (n 5 11) radiographic osteoarthritis. 3-T MR images with 2mm section thickness were acquired using a proton density-weighted, fat-suppressed, coronal, fast spinecho sequence. Segmentation of the tibial, femoral, and external surface of the medial meniscus and the tibial joint surface was performed. Three-dimensional parameters were computed to describe the shape, position, and signal intensity of the entire meniscus and three subregions (body, anterior, and posterior horn). Key results included a greater size (i.e., volume, surface areas, and thickness), increased medial extrusion (i.e., greater extrusion distance, greater meniscal area uncovered by tibial surface), and elevated signal intensity of the medial meniscus in osteoarthritis than in nonosteoarthritis knees, particularly in the meniscus body. These results need to be confirmed in larger cohorts, preferably under weight-bearing conditions. Magn Reson Med 63:1162-1171, 2010. V C 2010 Wiley-Liss, Inc.Key words: meniscus; osteoarthritis; extrusion; coverageThe meniscus plays an important role in normal knee function by providing a higher degree of joint conformity (congruity) and by distributing loads over a wider area (1). Meniscal pathology (i.e., extrusion and tears) is frequent in the general population, even among asymptomatic individuals, and becomes more common with increasing age (2). Meniscal pathology has also been associated with knee pain (3-6) and osteoarthritis (OA) progression, specifically with increased rates of cartilage loss (7-12). These findings have generally relied on semiquantitative scoring of the meniscus (4,13), and only few studies have utilized quantitative measures of meniscus position (subluxation) or shape (14-16).Gale et al. (14) used coronal fat-saturated proton density and T 2 -weighted images to investigate the relationship between meniscal extrusion (subluxation) and joint space narrowing in 233 participants with symptomatic knee OA and in 58 asymptomatic controls. They determined the degree of extrusion to the nearest millimeter in the image where the greatest distance between the most peripheral aspect of the meniscus and the border of the tibia (excluding osteophytes) was observed. The OA participants displayed more extrusion of the medial meniscus (MM) than controls (5.1 versus 2.8mm; P ¼ 0.001). Modest degrees of meniscal extrusion were common in controls, but severe degrees (>7mm) were unique to OA cases. Hunter et al. (15) explored the role of meniscal tears (semiquantitative scoring (13)), extrusion, and height as risk factors for cartilage loss in 257 subjects. Extrusion and height were measured quantitatively in the coronal MR image showing the maximal medial tibial spine volume and in two sagittal images, one through the medial and one through the lateral tibia. Meniscal coverage and height were smaller in knees with men...

The schuss view is suggested as the most accurate method for the evaluation of JSW in femorotibial OA.

Objective-The performance characteristics of hyaline articular cartilage measurement on magnetic resonance imaging (MRI) need to be accurately delineated before widespread application of this technology. Our objective was to assess the rate of natural disease progression of cartilage morphometry measures from baseline to 1 year in knees with osteoarthritis (OA) from a subset of participants from the Osteoarthritis Initiative (OAI).Methods-Subjects included for this exploratory analysis are a subset of the approximately 4700 participants in the OAI Study. Bilateral radiographs and 3T MRI (Siemans Trio) of the knees and clinical data were obtained at baseline and annually in all participants. 160 subjects from the OAI Progression subcohort all of whom had both frequent symptoms and, in the same knee, radiographic OA based on a screening reading done at the OAI clinics were eligible for this exploratory analysis. One knee from each subject was selected for analysis. 150 participants were included. Using sagittal 3D DESSwe (double echo, steady-state sequence with water excitation) MR images from the baseline and 12 follow-up month visit, a segmentation algorithm was applied to the cartilage plates of the index knee to compute the cartilage volume, normalised cartilage volume (volume normalised to bone surface interface area), and percentage denuded area (total cartilage bone interface area denuded of cartilage).Results-Summary statistics of the changes (absolute and percentage) from baseline at 1 year and the standardised response mean (SRM), ie, mean change divided by the SD change were calculated. On average the subjects were 60.9 years of age and obese, with a mean body mass index of 30. Despite being extraordinarily prevalent OA remains a condition that is poorly understood, and a condition for which available effective therapeutic options are limited to symptomatic treatment. The development of therapies aimed at joint preservation in OA is constrained by the slow progress of the condition, its heterogeneous clinical manifestations and the need for long-term follow-up to observe changes in structure. NIH Public AccessNew technologies may improve the assessment of early disease development, and progression, and could greatly facilitate measurement of structural outcomes in OA clinical trials. Foremost among these is magnetic resonance imaging (MRI), a sensitive non-invasive method for assessing joint morphology. 5 6 MRI is ideally suited for imaging arthritic joints as: (1) it is free of ionising radiation; (2) it defines both calcified as well as soft tissue joint components; and (3) its tomographic viewing perspective obviates morphological distortion, magnification and superimposition. MRI of the knee can directly visualise hyaline articular cartilage and cover the whole joint in one examination, meaning that the cartilage defects in the joint can be visualised directly regardless of their location. 5Although yet to be formally accepted by regulatory authorities, many experts now agree that MRI may b...