ABSTRACT
PURPOSE: To evaluate the ability of optical coherence tomography (OCT) to provide real-time, high-resolution structural analysis of the full thickness rabbit articular repair tissue following chondrocyte transplantation. MATERIALS AND METHODS: Full thickness articular cartilage defects were created in the patellar grooves of the distal femur of 30 adult rabbit knee joints. Allogenic cultured chondrocytes embedded in collagen gels were implanted into the surgical defects. Six animals per time point were sacrificed at 2, 4, 8, 12 and 24 weeks after surgery. The repair tissues were sequentially analyzed by arthroscopic surface imaging, OCT, and histology. RESULTS: OCT was able to identify the bone and cartilage interface in normal rabbit articular cartilage and regenerated cartilage at 24 weeks post chondrocyte implantation. OCT was able to identify fine surface fibrillations at 24 weeks. More importantly, OCT was able to detect the embedded gaps between the repair tissue and surrounding cartilage. CONCLUSION: OCT provides a minimal invasive means to obtain an instant "optical biopsy" of the rabbit articular repair tissue without damaging the specimen.