Differential acoustic properties of early cartilage lesions in living human knee and ankle joints

Abstract

Objective. Although numerous studies have been performed to determine whether there are histologic, biochemical, biomechanical, and metabolic differences between knee and ankle cartilage, none have investigated the presence of such differences in living human cartilage. We previously developed an ultrasonic evaluation system for articular cartilage that analyzes the A-mode echogram using wavelet transformation. The current study was undertaken to determine whether the acoustic properties of living human cartilage differ between knee and ankle joints.Methods. Twenty-eight patients were subjected to ultrasonic evaluation under arthroscopy. After arthroscopic grading, the cartilage was measured using an ultrasonic probe. Two quantitative parameters were used, i.e., the maximum magnitude and the echo duration at the 95% interval of the maximum magnitude.Results. In intact cartilage, the maximum magnitude and echo duration did not differ between the knee and the ankle. In lesional cartilage, in contrast, the maximum magnitude was higher, and the echo duration was shorter, in the ankle than in the knee. These differences were statistically significant.Conclusion. Ultrasound findings could be used to judge the degree of early cartilage degeneration in vivo on the basis of objective data such as the maximum magnitude and echo duration. Because we were unable to quantitatively analyze the biochemical and biomechanical properties of the cartilage in this study, our biochemical and biomechanical findings are based only on qualitative assessment. Nevertheless, the results indicate that this ultrasonic evaluation system may be useful for elucidating the processes of articular cartilage degeneration in osteoarthritis.Osteoarthritis (OA), also referred to as degenerative joint disease, is one of the most prevalent chronic conditions, although not all joints are equally affected by the disease (1). Studies of cadavers have revealed that full-thickness cartilage defects occur ϳ20 times more often in the knee than in the ankle (2,3). Symptomatic OA with radiographic changes occurs ϳ8-9.4 times more frequently in the knee than in the ankle in patients seeking treatment (4,5). Therefore, several researchers have focused on comparing the cartilages from these 2 joints to determine whether they possess histologic, biochemical, biomechanical, and/or metabolic differences (6-10). There has been a great deal of effort, in studies using cartilage from cadavers, to elucidate the differences between these 2 joints. Indeed, such studies may help us to understand the different susceptibilities of these 2 joints and the pathogenesis of OA in general. However, none of these investigations have been conducted with living human cartilage.We previously developed a novel system for evaluating articular cartilage, in which the acoustic properties of articular cartilage are measured by introducing an ultrasound probe into the knee joint under arthroscopy (11,12). The analysis system is based on wavelet transformation of the reflex echogram from arti...

Imaging the joint in osteoarthritis: a place for ultrasound?

“…In OA, sonography has shown its capability in detecting and evaluating a large number of abnormalities involving hyaline cartilage, synovial fluid and synovial membrane, menisci, joint capsule and bursae as well as in the bony cortex [1,11,21,[23][24][25][26][27][28][29][30][31][32][33][34][35][36]. Recent development of high-resolution transducers and more powerful machines has rendered US an emerging and even more widely used tool to image and investigate both early and late changes in OA [9,11,17,32,33].…”

Mouse models of graft-versus-host disease

“…The Fas-FasL pathway is particularly important in hepatic GVHD, consistent with the keen sensitivity of hepatocytes to Fas-mediated cytotoxicity in experimental models of murine hepatitis (Van Den Brink et al, 2000). Fas-deficient recipients are protected from hepatic GVHD, but not from other organ GVHD, and administration of anti-FasL (but not anti-TNF) MAbs significantly blocked hepatic GVHD damage occurring in murine models (Van Den Brink and Burakoff, 2002;Van Den Brink et al, 2000;Hattori et al, 2005). Although the use of FasL-deficient donor T cells or the administration of neutralizing FasL MAbs had no effect on the development of intestinal GVHD in several studies, the Fas-FasL pathway may play a role in this target organ, because intestinal epithelial lymphocytes exhibit increased FasL-mediated killing potential (Lin et al, 1998).…”

A Pilot Feasibility Study for Ultrasound Evaluation of Living Human Wrist Cartilage: Site-Specific Differences in Acoustic Properties

“…We analyzed the reflex ultrasound echoes from articular cartilage by wavelet transformation and revealed that the maximum magnitude is correlated with the aggregate modulus from indentation tests. 9 Moreover, we previously applied this method to knee and ankle joints under arthroscopy 11 and in the current study have applied it to living human wrists for the first time.…”

“…The distribution pattern of the wrist cartilage data was spindle-shaped along the y axis and similar to that for ankle cartilage data. 10,11 The mean maximum magnitude and echo duration were 3.41 Ϯ 1.50 (range, 0.89 -7.53) and 1.33 s Ϯ 0.30 (range, 0.51-2.17 s), respectively.…”