Low-field standing magnetic resonance imaging findings of the metacarpo/metatarsophalangeal joint of racing Thoroughbreds with lameness localised to the region: a retrospective study of 131 horses.

The research article focuses on the utilization of low-field magnetic resonance imaging (MRI) to detect pathologies in the metacarpo/metatarsophalangeal (MCP/MTP) joint of Thoroughbred racehorses experiencing lameness. It finds that MRI facilitates a definitive diagnosis, highlighting conditions that may not be revealed through traditional radiographic imaging, including fractures that may lead to severe injuries.

Overview of the Research

• The study delves into the application of low-field MRI in detecting and diagnosing health issues in the MCP/MTP joint, a common source of lameness in Thoroughbred racehorses.
• The study hinges on the premise that conventional radiographic imaging methods might not always reveal pathologies that align with the degree of lameness, hence warranting alternative diagnostic procedures.
• Especially, stress fractures that occur in the distal third metacarpal/metatarsal (MC3/MT3) condyles and proximal phalanx demand a definitive diagnosis, prompting a shift towards MRI.
• The study reviews the MR images and clinical records of Thoroughbred racehorses that underwent an MRI of the MCP/MTP joint from October 2006 to August 2010.

Findings from the Research

• High-quality diagnostic images were obtained from 97.8% of the horses studied. This underscores the efficacy of MRI in generating quality images that can guide diagnosis.
• The dominant finding was a palmar/plantar osteochondral disease in MC3/MT3, which was seen in 54.9% of the horses.
• Around 19.8% of the horses were diagnosed with an incomplete condylar fracture, primarily in the lateral condyle, reinforcing the necessity of the MRI approach.
• Other findings included incomplete sagittal fractures of P1 (14.5%), ‘dorsal joint disease’ (11.4%), transverse MC3 stress fractures (1.5%), soft tissue injuries (12.2%), and proximal phalangeal ‘contusions’ (3.8%). No significant bone/soft tissue injury was found in 5.4% of the cases.

Conclusion and Implications of the Research

• The research concludes that standing MRI can detect a wide range of diseases in the MCP/MTP joints of racehorses. The procedure is notably well-tolerated, allowing for a definitive diagnosis in cases where radiographic imaging proves insufficient.
• Importantly, 35.8% of the cases showed MRI findings consistent with fracture pathology, which could not be confirmed radiographically at the time of the MRI examination. This observation carries significant therapeutic and prognostic implications and could help prevent catastrophic injury.