Details

Autor(en) / Beteiligte

• Pierantoni, Maria
• Hammerman, Malin
• Silva Barreto, Isabella
• Larsson, Daniel
• Notermans, Thomas
• Bodey, Andrew J.
• Eliasson, Pernilla
• Isaksson, Hanna

Titel

Spatiotemporal and microstructural characterization of heterotopic ossification in healing rat Achilles tendons

Ist Teil von

• The FASEB journal, 2023-06, Vol.37 (6), p.n/a

Ort / Verlag

United States

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Achilles tendon rupture is a common debilitating medical condition. The healing process is slow and can be affected by heterotopic ossification (HO), which occurs when pathologic bone‐like tissue is deposited instead of the soft collagenous tendon tissue. Little is known about the temporal and spatial progression of HO during Achilles tendon healing. In this study we characterize HO deposition, microstructure, and location at different stages of healing in a rat model. We use phase contrast‐enhanced synchrotron microtomography, a state‐of‐the‐art technique that allows 3D imaging at high‐resolution of soft biological tissues without invasive or time‐consuming sample preparation. The results increase our understanding of HO deposition, from the early inflammatory phase of tendon healing, by showing that the deposition is initiated as early as one week after injury in the distal stump and mostly growing on preinjury HO deposits. Later, more deposits form first in the stumps and then all over the tendon callus, merging into large, calcified structures, which occupy up to 10% of the tendon volume. The HOs were characterized by a looser connective trabecular‐like structure and a proteoglycan‐rich matrix containing chondrocyte‐like cells with lacunae. The study shows the potential of 3D imaging at high‐resolution by phase‐contrast tomography to better understand ossification in healing tendons. In this study, we characterize the heterotopic ossifications (HO) at different stages of healing (1, 2, 3, 6, 12, 16 and 20 weeks postinjury) in a rat model. We investigate deposition, microstructure, and location by phase contrast‐enhanced synchrotron microtomography (SR‐PhC‐μCT), a state of the art technique that allows 3D imaging at high‐resolution of soft biological tissues, in combination with histology. The schematic shows an overview of a 12 week healing tendon imaged by SR‐PhC‐μCT from the muscle junction to the heal bone junction (HO deposits appear in bright white within the healing tissue) and a cross‐section showing two types of HO deposits (* vs. triangle). Histology shows chondrocyte‐like cells with lacunae in an HO deposit form a 12‐week healing tendon stained with nuclear fast red & alcian blue (left) or hematoxylin & eosin (right).