New technology for assessing microstructural components of tendons and ligaments.

This study investigated the ability of optical coherence tomography (OCT), a recently developed technology with micron-scale resolution, to assess the microstructure of tendons and ligaments. In vitro structural- and polarization-sensitive OCT was performed on human ACL, Achilles tendon, and biceps tendon (obtained postmortem). Histology was performed on all imaged samples and compared to the corresponding OCT data. OCT images correlated well with histology. Most importantly, through polarization-sensitive OCT, the collagen in normal tissue was easily distinguished from the surrounding, supportive tissue due to the birefringent properties of organized collagen. Since the integrity of collagen is an important indicator of structural stability and pathologic state, the ability of OCT to assess collagen could be a powerful diagnostic tool in assessing tendon and ligament properties.