Objective: Accurate, high-resolution imaging of articular cartilage thickness is an important clinical challenge in patients with osteoarthritis, especially in small joints. In this study, computed tomography (CT) mediated catheter-based optical coherence tomography (OCT) was utilized to create a digital reconstruction of the articular surface of the trapeziometacarpal (TMC) joint and to assess cartilage thickness in comparison to cryomicrotome data.
Design: Using needle-based introduction of the OCT probe, the articular surface of the TMC joint of 5 cadaver wrists was scanned in different probe positions with matching CT scans to record the intraarticular probe trajectory. Subsequently and based on the acquired CT data, 3-dimensional realignment of the OCT data to the curved intraarticular trajectory was performed for all probe positions. The scanned TMC joints were processed using a cryomicrotome imaging system. Finally, cartilage thickness measurements between OCT and cryomicrotome data were compared.
Results: Successful visualization of TMC articular cartilage was performed using OCT. The CT-mediated registration yielded a digital reconstruction of the articular surface on which thickness measurements could be performed. A near-perfect agreement between OCT and cryomicrotome thickness measurements was found (r2 = 0.989).
Conclusion: The proposed approach enables 3D reconstruction of the TMC articular surface with subsequent accurate cartilage thickness measurements, encouraging the development of intraarticular cartilage OCT for future (clinical) application.
Keywords: articular cartilage; co-registration; computed tomography; imaging cryomicrotome; optical coherence tomography.