VALIDATION OF AN OPTICAL METHOD FOR MEASURING THE GAP BETWEEN SUTURED TENDON STUMPS

Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine

ABSTRACT Objective: This study aims to investigate the accuracy and precision of an optical measurement method based on backlight video analysis for measuring gap distances between tendon stumps in a rigid tendon model. Methods: A rigid 3D-printed tendon model was sutured and subjected to traction using a universal mechanical testing machine. The gap between stumps was filmed in frontal and lateral planes with backlight illumination and a simple mirror system. A custom software program calculated gap distances from the recorded videos and the optical measurements were compared with mechanical testing machine measurements to assess precision and accuracy. Results: The mean difference (bias) in the frontal plane was -0.01 mm (SD: 0.01 mm) and in the lateral plane was 0.04 mm (SD: 0.03 mm). Bland-Altman analysis showed limits of agreement (LoA) of 0.04 mm in the frontal plane and 0.06 mm in the lateral plane. Measurements between planes showed a very strong correlation with a Spearman's rho correlation test of 1.000 (p<0.001). Conclusion: The optical method showed errors on the order of hundredths of a millimeter and proved to be both precise and accurate, validating a new method for gap measurement in biomechanical tendon studies.