Design, Development and Validation of a Knee Brace to Standardize the US Imaging Evaluation of Knee Osteoarthritis

Objective: A repeatable and reliable follow-up of knee injuries would be desirable to prevent
delayed diagnosis and to monitor the efcacy of the applied treatment over time. Ultrasound (US) techniques
are an attractive option to this purpose, since they are safe, low-cost and non-invasive. However, its use in
the clinical practice is limited by the high dependency on the operator's experience. Hence, the objective of
this study is to provide a standardization of the US image acquisition process for knee osteoarthritis (OA)
allowing an extended clinical use of US technologies in this domain. Methods: Clinical specications were
provided by expert musculoskeletal radiologists thus identifying the subject poses and the US probe positions
needed to evaluate the cartilage structure, signs of synovitis and joint effusion. Such considerations were
used to derive the technical requirements needed for the development of a wearable brace equipped with
specic openings to guide the correct placement of the probe. The feasibility of the developed wearable
brace was tested on three healthy volunteers, which were asked to acquire informative US images, similar to
the reference images performed by the musculoskeletal radiologist. Results: Thanks to the knee brace, the
untrained subjects were able to self-acquire informative B-mode images comparable to the corresponding
images acquired by an expert clinician. Discussion/Conclusion: The use of a knee brace intended for knee
OA US diagnosis demonstrated the possibility to standardize the acquisition protocol and make its application
achievable also for untrained subjects, representing a key step toward tele-ultrasonography.