Abstract
We examined knee joint sounds using an Electronic Stethoscope. 4000 model (ES 4000: 3M LittmannTM). The stethoscope was set on the medial, lateral and suprapatellar sides, and joint sounds were recorded during flexion-extension motions. The joint sound recordings were converted to phonographs displaying sound oscillations or sound frequencies using proprietary software. The objects investigated were 12 joints of grade-0 (a physically unimpaired person), 12 joints, grade-1, 10 joints of grade-2, 16 joints of grade-3, and 8 joints of grade-4 by the Kellgren & Lawrence grading system. The sounds recorded at the suprapatellar side were the most audible. The K-L grading system was thought to be relative to the production of joint sound. In osteoarthritis knees, the phonographs showed that there was a high incidence of high frequency sound. The highest frequency recorded was less than 1 kHz. We concluded that joint auscultation with the ES4000 stethoscope was useful as a method for the early detection and dynamic joint function estimation for gonarthrosis.
