Comparison Between In Vitro and Simulated Arthroscopy Electromechanical Measurements of Human Articular Surfaces Using the Arthro-BST

Materials & Methods: One closed cadaveric knee joint was obtained from Science Care (Arizona, USA). An orthopaedist opened the joint and defined 12 measurement sites on the distal femur with a permanent marker. The joint was then closed with stitches to perform arthroscopy. The distal femur was then isolated from the joint and in vitro measurements were performed at matched sites by 4 users (the orthopaedist and 3 engineers). Visual ICRS scoring and histological Mankin scores were obtained for all sites. In this study, we reanalyzed all electromechanical output from the Arthro-BST by taking the first valid measurement only. The Arthro-BST (Biomomentum Inc., Laval, Canada) calculates a quantitative parameter which is inversely proportional to the electromechanical activity of cartilage.

Results: An intraclass correlation coefficient (ICC) of 0.85 (95%CI: 0.68–0.95) was calculated among the four users, while an ICC of 0.89 (95%CI: 0.63–0.97) was found between QP values obtained under simulated arthroscopy and in vitro. Strong correlations were found between simulated arthroscopy and in vitro QP values (r=0.83, p=0.0009, N=12, Fig.1). Strong correlations were also obtained between the QP values obtained arthroscopically and the Mankin Score (r=0.84, p=0.0007, N=12, Fig.2a) and the ICRS Scoring (r=0.80, p=0.001, N=12, Fig.2b).

Conclusion: This study revealed strong correlations of QP values obtained in arthroscopy with histological Mankin and visual ICRS scores. In addition to correlation of QP with gold standards, high ICCs suggest that the Arthro-BST could be considered as a powerful tool for articular cartilage assessment.