Articular Sound and Clinical Stages in Knee Arthropathy

Abstract

Objective: To clarify the pathophysiology of knee arthropathy, articular sound in the knee joint was recorded using an accelerometer, vibroarthrography (VAG), during standing-up and sitting-down movements in patients with osteoarthropathy (OA) of the knees. Methods: VAG signals and angular changes of the knee joint during standing-up and sitting-down movements were recorded in patients with OA, including 17 knees with OA at KellgrenÀLawrence stage I and II, 16 knees with OA at III and IV stages, and 20 knees of age-matched control subjects. Results: The level of VAG signals was greater in knees with a higher stage of OA at 50À99 and 100À149 Hz among the groups (ANOVA with TukeyÀKramer multiple comparisons test, p < 0:01). The VAG signals did not correlate with WOMAC-pain or physical scores. Conclusions: We considered that the increase in VAG signals in these ranges of frequency corresponded with pathological changes of OA, but not self-reported clinical symptoms. This method of VAG can be used by clinicians during interventions to obtain pathological information regarding structural changes of the knee joint.

Preliminary study of optimal measurement location on vibroarthrography for classification of patients with knee osteoarthritis

“…Previous studies described a difference in the frequency based on FFT7, 8 ) or signal variations (jitter and shimmer analysis)13 ) between normal knee and knees with OA. So far, however, there are no true VAG data between the femur and tibia, because it is impossible to measure areas just next to impact in vivo .…”

“…A previous study8 ) demonstrated that a high frequency area (200−600 Hz) obtained by fast Fourier transform (FFT) is a key feature of knee OA. Another study7 ) reported that a frequency of 50−150 Hz in patients with knee OA using FFT was higher than that in age-matched elderly. FFT does not take time information into account, and therefore FFT analysis cannot be applied to investigate the relationship between knee joint motion and VAG signal frequency information.…”

“…Vibroarthrography (VAG) is a noninvasive method of assessing cartilage degeneration or knee OA4,5,6,7,8 ) . A previous study8 ) demonstrated that a high frequency area (200−600 Hz) obtained by fast Fourier transform (FFT) is a key feature of knee OA.…”

“…The accelerometer and microphone used to measure VAG signals from the knee joint were positioned around knee joint areas, such as the medial or lateral femoral condyles7, 8 ) . The skin around the knee joint locations was expected to move during the tasks (gait, standing up, and walking up and down stairs).…”

Joint motion quality in vibroacoustic signal analysis for patients with patellofemoral joint disorders

“…It is based on recording the vibroacoustic signal during movement of articular surfaces. It has been demonstrated that VAG signals generated by degenerative cartilage differ from healthy joint signals[ 17 , 18 ]. Although the VAG method is still in development, it shows repeatability in subsequent motion cycles[ 15 , 19 ] and in addition accuracy of over 90% when compared with the clinical findings made in the standard diagnostic procedures[ 11 , 20 ].…”