Ex vivo magnetic resonance imaging of the distal row of equine carpal bones: assessment of bone sclerosis and cartilage damage.

The research investigated the capability of Magnetic Resonance (MR) imaging in identifying cartilage and bone lesions in the distal row of carpal bones in horses. The findings suggest that MR imaging can successfully detect minor cartilage and bone lesions not visible through radiography or macroscopic examination.

Introduction and Methodology

• The researchers used the distal row of carpal bones (C2, C3, and C4) from eight left intercarpal joints sourced from four Standardbred Trotters and four Swedish Warmblood horses.
• The prime objective was to evaluate MR imaging’s potential in detecting cartilage and bone lesions.
• The joints used for this study were already classified based on macroscopic and radiographic examinations. Levels of classification included normal, mild, moderate, or severe articular cartilage lesions and bone sclerosis.

Outcomes and Analyses

• After MR imaging of the joints, researchers found that the classifications made using the macroscopic and radiographic examinations correlated well with the MR images.
• Bone sclerosis or the hardening and abnormal density of the bone tissue was observed in the MR images as regions displaying decreased signal intensity.
• A quantitative analysis of the MR images showcased a significant difference in signal intensity between areas showing radiographic bone sclerosis and areas with radiographic nonsclerotic bone.

Use of Histology

• The team used the MR images to guide the placement of histology slices, which were then examined under a microscope.
• This double-check procedure ensured the lesions identified from the MR imaging were accurately confirmed through microscopic verification.

Conclusion and Applications

• The researchers concluded that the condition of the cartilage, including lesions and loss, is linked to the sclerosis of underlying bone.
• The research demonstrated that MR imaging could detect minor cartilage and bone lesions in cadaveric carpal joints that were not visible using radiography or macroscopic examination.
• Another significant finding was that the MR imaging protocols designed in this study can be used effectively on intact joints.
• The study’s conclusion emphasizes the utility of MR imaging in tracking changes in the interactions between the articular cartilage and subchondral bone over time and in live subjects.