Three-dimensional visualization of lumbar facet joint degeneration by using synchrotron radiation-based propagation phase contrast micro-tomography

English Keywords:Synchrotron radiation  Phase contrast imaging  Lumbar facet joint  Three-dimensional visualization

English Abstract:

  【Abstract】 Objectives: To investigate the three-dimensional morphology of lumbar facet joint(LFJ) in rats using synchrotron radiation-based propagation phase contrast micro-tomography(SR-PPCT), and to discover the potential mechanism of lumbar zygapophysial joint pain. Methods: L4/5 LFJs were harvested from healthy SD rats of young and aging group respectively. The specimens were scanned by SR-PPCT at BL13W1 of Shanghai Synchrotron Radiation Facility(SSRF) in China. The three-dimensional visualization images of LFJs were reconstructed by VG Studio Max for further analysis. Independent sample t test was used to compare the differences of LFJ cartilage, subchondral bone plate, cancellous bone and joint space between two groups of rats. Results: The joint space, cartilage thickness, cartilage volume, subchondral bone plate thickness, subchondral bone(BV/TV), (BS/TV) and cancellous bone(TbN) of young group′s LFJs were 38.00±4.50μm, 15.6±0.63μm, (51.25±1.49)×104μm3, 16.37±1.23μm, (60±5)%, 180±20mm-1, 6.85±0.31mm-1 respectively. The data LFJs of aging group were 16.25±0.85μm, 18.90±2.14μm, (37.00±1.83)×104μm3, 72.48±3.14μm, (87±4)%, 0.97±0.08mm-1, 2.07±0.21mm-1. Compared with the young group, the LFJs of aging group′s joint space was narrowed, the cartilage volume was decreased, the subchondral bone plate became thicker, the void-like structure gradually disappeared, and the number of trabecular bone in the subchondral was decreased. Conclusions: Synchrotron radiation phase contrast imaging enables the simultaneous visualization of both cartilage and subchondral bone with high precision. During LFJ degeneration, subchondral bone changes appear in parallel to the cartilage degeneration, and the changes in one component (cartilage or subchondral bone) cause adaptive changes.