The use of Phonoarthrometry to detect Osteoarthritis in the Human Knee Joint: A Clinical Proof of Concept Study

The potential clinical value of sounds and vibrations produced by joints as they move has been studied extensively since 1902 however as of yet no clinically useful device exists. The phonoarthrometer is an experimental prototype diagnostic tool which has the potential to detect joint disorders through interpretation of the sounds produced when the knee joint is moved naturally. The study aims to evaluate the phonoarthrometers’ clinical usefulness through its ability to detect osteoarthritis of the human knee joint. Investigation of the phonoarthrometers’ ability to detect osteoarthritis involved taking the prototype device into a clinical environment and using it to test osteoarthritic affected knee joints. A dataset from knee joints defined as normal was also collected for use in the building of the core microstructure database and for use as a comparative control group. The vibration signal of the knee joint was collected via accelerometer sensors placed at the patella and a medial joint line. An electro-goniometer was used to collect the angular data of the knee in motion. All participants were required to complete a set of test protocols designed to gather both loaded and unloaded data from the knee joint. Collected data was then analysed using the phonoarthrometer software. The phonoarthrometer was able to differentiate an osteoarthritic knee vibration response from a healthy normal knee response. This manifested as a greater level of suppression in the vibration response from the osteoarthritic knee group compared with the normal knee group. Detection between medial and lateral compartment osteoarthritis was possible due to differences in the suppression level of the vibration signal. Determination of the severity of the osteoarthritis in the affected knee was not consistent enough to be conclusive. The phonoarthrometer in its current state of development would be limited in its usefulness as a diagnostic device. Further improvements to its detection ability are needed to allow the level of detail needed for a clinically useful diagnosis.