Three-dimensional characterization of the microstructure in rabbit patella–patellar tendon interface using propagation phase-contrast synchrotron radiation microtomography

Abstract

Understanding the three-dimensional ultrastructure morphology of tendon-tobone interface may allow the development of effective therapeutic interventions for enhanced interface healing. This study aims to assess the feasibility of propagation phase-contrast synchrotron radiation microtomography (PPC-SRmCT) for three-dimensional characterization of the microstructure in rabbit patella-patellar tendon interface (PPTI). Based on phase retrieval for PPC-SRmCT imaging, this technique is capable of visualizing the three-dimensional internal architecture of PPTI at a cellular high spatial resolution including bone and tendon, especially the chondrocytes lacuna at the fibrocartilage layer. The features on the PPC-SRmCT image of the PPTI are similar to those of a histological section using Safranin-O staining/fast green staining. The threedimensional microstructure in the rabbit patella-patellar tendon interface and the spatial distributions of the chondrocytes lacuna and their quantification volumetric data are displayed. Furthermore, a color-coding map differentiating cell lacuna in terms of connecting beads is presented after the chondrocytes cell lacuna was extracted. This provides a more in-depth insight into the microstructure of the PPTI on a new scale, particularly the cell lacuna arrangement at the fibrocartilage layer. PPC-SRmCT techniques provide important complementary information to the conventional histological method for characterizing the microstructure of the PPTI, and may facilitate in investigations of the repair mechanism of the PPTI after injury and in evaluating the efficacy of a different therapy.

Effect of Mechanical Stimulation Combined With Platelet-Rich Plasma on Healing of the Rotator Cuff in a Murine Model

“…After fixing the specimen in this solution and setting in a refrigerator at 4°C for 24 hours, we placed it in a micro-CT scanner (Scanco Medical). 56 Specimen analysis was performed using the CTAn, DataViewer, and CTVol programs of Sky-Scan data analysis software (SkyScan NV, Belgium). The scanning parameters were as follows: resolution, 10.4 mm; energy, 55 kVp; exposure time, 0.4 seconds; rotation step, 0.36°; and rotation, 180°.…”

Heterotopic mineral deposits in intact rat Achilles tendons are characterized by a unique fiber-like structure

“…We use a rat model in combination with cutting-edge high-resolution phase contrast enhanced synchrotron X-ray tomography to increase our knowledge of the process of HO deposition at the microscale in intact Achilles tendons. This technique offers the unique possibility to rapidly image relatively large volumes with micrometer resolution, without the need of invasive sample preparations (Gonzalez-Tendero et al, 2017;Horng et al, 2014;Zhou et al, 2018;Disney et al, 2017;Eckermann et al, 2020;Gradl et al, 2019;Horng et al, 2021). Because of low absorption and small density differences, imaging soft biological materials by conventional tomography is challenging.…”

Effect of Platelet-Rich Plasma at Different Initiation Times on Healing of the Bone-Tendon Interface of the Rotator Cuff in a Mouse Model

“…Subsequently, the specimens were placed in a micro-CT scanner (Scanco Medical). 44 Image acquisition and data analysis were performed using CTAn, DataViewer, and CTvol software (SkyScan). The scanning parameters were as follows: resolution, 10.4 μm; energy, 55 kVp; exposure time, 0.4 seconds; rotation step, 0.36°; and rotation, 180°.…”