When measuring design complexity (DC) in the field of medical devices, some of the aspects to consider are the

number of components, interactions between components, part variations and the product’s overall functionality.

Taking into consideration these aspects, several authors have developed metrics in an effort to quantitatively

measure DC. While these metrics consider DC from different perspectives, there is an underlying relationship

between each one. This paper presents a study of seventy-five knee replacement devices in an effort to understand the connection between these factors and complexity. To achieve this, product information and surgical techniques were gathered to analyze the devices’ complexity using six DC metrics. Furthermore, a correlation analysis was performed to unravel the relationships between these metrics for knee replacements and in contrast to previous results with hip replacements. This research provides a framework for future developments with an understanding of complexity metrics in the field of medical devices.