Presented at the American Association of Equine Practitioners, 56th Annual Convention, 2010, Baltimore, Maryland.
FRACTURES OF THE DISTAL PHALANX AND ASSOCIATED SOFT TISSUE AND OSSEOUS ABNORMALITIES IN 22 HORSES WITH OSSIFIED SCLEROTIC UNGUAL CARTILAGES DIAGNOSED WITH MAGNETIC RESONANCE IMAGING
Version of Record online: 20 MAY 2011
© 2011 Veterinary Radiology & Ultrasound
Veterinary Radiology & Ultrasound
Volume 52, Issue 4, pages 394–401, July/August 2011
How to Cite
SELBERG, K. and WERPY, N. (2011), FRACTURES OF THE DISTAL PHALANX AND ASSOCIATED SOFT TISSUE AND OSSEOUS ABNORMALITIES IN 22 HORSES WITH OSSIFIED SCLEROTIC UNGUAL CARTILAGES DIAGNOSED WITH MAGNETIC RESONANCE IMAGING. Veterinary Radiology & Ultrasound, 52: 394–401. doi: 10.1111/j.1740-8261.2011.01813.x
- Issue online: 19 JUL 2011
- Version of Record online: 20 MAY 2011
- Received April 14, 2010; accepted for publication February 2, 2011.
- distal phalanx;
- ungual cartilage
Ungual cartilage ossification in the forelimb is a common finding in horses. Subtle abnormalities associated with the ungual cartilages can be difficult to identify on radiographs. Magnetic resonance (MR) imaging findings of 22 horses (23 forelimbs) with a fracture of the distal phalanx and ossified ungual cartilage were characterized and graded. All horses had a forelimb fracture. Eleven involved a left forelimb (seven medial; four lateral), and 12 involved a right forelimb (five medial; seven lateral). All fractures were nonarticular, simple in configuration, and nondisplaced. The fractures were oriented in an axial proximal to abaxial distal and palmar to dorsal direction, and extended from the base of the ossified ungual cartilage into the distal phalanx. The fracture involved the fossa of the collateral ligament on the distal phalanx in 17 of 23 limbs. The palmar process and ossified ungual cartilage was abnormally mineralized in all horses. Ligaments and soft tissues adjacent to the ossified ungual cartilages were affected in all horses. The routine site of fracture in this study at the base of the ossified ungual cartilage extending into the distal phalanx suggests a biomechanical cause or focal stress point from cycling. The ligamentous structures associated with the ungual cartilages were often affected, showed altered signal intensity as well as enlargement and were thought to be contributing to the lameness. In conclusion, ossified ungual cartilages may lead to fracture of the palmar process of the distal phalanx and injury of the ungual cartilage ligaments.