Vibrational Analysis on Patellofemoral Joint Degradation of Swine’s Knee

Abstract

Knee’s severe patellofemoral joint degeneration gives a lot of people difficulty to endure daily life because walking or any leg movement can cause serious pain. At present, physical examination, x-ray and MRI are often used to diagnose the condition; however, each of the methods has its own disadvantages. For instance, physical examination is highly dependent on the skill of the doctor who practiced the examination, which cannot avoid misdiagnosing the condition. X-ray can detect wounds and tears, but the accuracy is also not top-notch since the result of an x-ray is a 2-dimension picture. MRI is the most reliable method for diagnosing the condition; however, the cost is very high. We propose that other than x-ray and MRI, patellofemoral joint degeneration can be identified by analyzing vibrational signals obtained from an accelerometer attached to the patella while sitting and moving the leg up and down. At the beginning of the study, swine’s knees are used to imitate human’s knee. Swine’s knees with various surface degradation levels are put on a machine that mimics the mechanism of knee motion. An accelerometer is mounted on the patella of the swine’s knee while the machine is running to measure the friction and roughness induced vibration of the patella. The vibration results suggest that more surface degradation the higher vibration signal amplitude. Nevertheless, the method still needs a lot more improvement on the database and testing procedures, in order to make it accurate, dependable and affordable. Hence, with further analysis on patient’s knees it is highly possible to determine whether patient’s knee is degraded or not and at what degradation level.