Development of a Multi-Sensor Array for Non-Radiographic Micromotion Detection of Joint Prostheses

Total joint arthroplasty procedures are increasing year on year, however, the complications that are associated with the joint arthroplasty remain. Using total elbow arthroplasty as a case study due to the high loosening rates, a technique has been further developed to accurately monitor the position of the prosthesis. Micromotion detection of endoprosthetic elbow prostheses is vital for longevity along with timely, adequate treatment. At present, radiographs are used to monitor the prostheses position at the macro-scale which lacks in early detection of prostheses loosening. In this work, a multiple magnetic sensor (multi-sensor) configuration was designed that can detect real-time micromotion of the elbow prosthesis without the use of radiographs. The proposed approach can detect 0.15 mm micromotion with an average error below 0.05 mm linearly. This method also eliminated the tilting effect and increase the sensitivity of the system to 18 mm along with improving the signal to noise ratio and reducing RMS error compared to a single sensor configuration.