It may be that the fibrosis of fat associated with chronic obesity predisposes to this. Īn anecdotal observation on magnetic resonance imaging (MRI) is that in some patients with a large amount of subcutaneous fat around the knee, there are sheet-like collections of fluid in the subcutaneous fat particularly over the extensor mechanism (Fig. However, adipose is poorly oxygenated in the obese state and hypoxia has been shown to stimulate the propagation of pro-inflammatory adipokynes, resulting in adipose tissue fibrosis. Healthy adipose expansion relies on the presence of a well-coordinated process including the presence of endothelial precursor cells and pre-adipocytes. Obesity also adversely affects the biomechanics of fat surrounding joints. Obese individuals walk more slowly with shorter and broader strides, have a longer stance duration and a greater toe-out angle when compared with normal weight individuals. Increased body weight in obesity leads to changes in both joint loading and joint biomechanics during normal day-to-day activities. These changes are largely attributed to a combination of increased load and altered joint biomechanics. Numerous studies have demonstrated the role obesity plays in the development of osteoarthritis, cartilage defects, bone marrow lesions, pes anserine syndromes, and patello-femoral osteoarthritis. It is well established that obesity is an important risk factor for structural alterations in the knee joint. This may be caused by shearing injuries in fat with reduced elasticity associated with metabolic syndrome. Subcutaneous fluid around the knee is associated with an increased amount of subcutaneous fat, anterior to the knee extensor mechanism. Consensus agreement demonstrated all T2 hyper-intense lesions were anterior to the knee extensor mechanism. The median cross-sectional area of fat for the study group was 62.29cm 2 (IQR 57.1–66.5) and for controls was 32.77cm 2 (IQR 24.8–32.3) which was significantly different ( p < 0.0001). The mean cross-sectional area of bone for patients with T2 hyper-intense lesions was 31.79cm 2 (SD 2.57) and for controls 30.11cm 2 (SD 3.20) which was not significantly different ( p = 0.09). Inter and intra-rater intraclass reproducibility was “excellent” (ICC > 0.8). The location of T2 signal hyper-intense lesions was characterized by consensus. Two observers independently drew regions of interest representing cross-sectional areas of bone and fat. Age and gender-matched patients without abnormal T2 MR signal changes were selected. Following a sample size calculation on pilot data, eighteen sequential patients demonstrating hyper-intense subcutaneous signal changes around the knee on fat-saturated T2-weighted MRI were identified from PACS (18 females, mean age 45, range 31–62). This was a retrospective case-control study. The purpose of this study was to determine if there is a difference in the amount of subcutaneous fat around the knee between patients with these appearances and controls. This may be caused by chronic low-grade shearing injuries in patients who are overweight. Fluid in the subcutaneous fat is a common finding anterior to the knee on MRI.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |