High resolution imaging of normal and osteoarthritic cartilage with optical coherence tomography

Objective. We describe optical coherence tomography (OCT), a high resolution micron scale imaging technology, for assessment of osteoarthritic articular cartilage microstructure. OCT is analogous to ultrasound, measuring the intensity of backreflected infrared light rather than acoustical waves. Methods. OCT imaging was performed on over 100 sites on 20 normal and osteoarthritic cartilage specimens in vitro. Results. Microstructures that were identified included fibrillations, fibrosis, cartilage thickness, and new bone growth at resolutions between 5 and 15 μm. In addition, the polarization sensitivity of imaging suggested a diagnostic role of polarization spectroscopy. Conclusion. OCT represents an attractive new technology for intraarticular imaging due to its high resolution (greater than any available clinical technology), ability to be integrated into small arthroscopes, compact portable design, and relatively low cost.