Last Updated on March 29, 2022 by Allison Price
Lameness in racehorses is often caused by osteochondral fractures (carpal chips fractures) of the wrist bones. Trauma, which is often associated with intense exercise, is the primary cause of lameness. The dorsal side of the joint is where chips are most common. The distal radial and proximal third bones are the most common locations in the middle carpal joint. The radiocarpal joint’s most popular locations include the proximal intercarpal bone, distal radius, proximal-radial carpal bones, and distal medial radius. The radiographic evidence of an osteochondral fragment or two and clinical signs such as synovitis, capsulitis, and radiographic confirmation of capsulitis are used to diagnose the condition. Arthroscopic surgery should be the first choice. The extent of articular cartilage injury within the joint is a major determinant of the overall prognosis.
Carpal Slab Fractures
Radiograph of the third carpal bone slab fracture, horse
Slab fractures can occur from one articular to another. Slab fractures can occur in the carpus in both the frontal and sagittal planes. A frontal slab fracture of radial bone third carpal is the most common. This is followed by fractures to the intermediate and facets bones. Lag screw fixation is the best option for fractures greater than 10 mm. If fracture fragments are too thin or unsuitable, they can be removed.
Accessory Carpal Bone Fractures
COURTESY OF DR. MATTHEW T. BROKKEN.
These fractures are much less common than those in the carpus. The most common cause of lameness is acute and severe. There may also be synovial effusion within the carpal sheath or, less frequently, the radiocarpal joint. Radiographs confirm this diagnosis. The majority of these fractures can be treated conservatively. However, if the fractures are articular or fragmented, surgery may be necessary. Horses may be able to resume athletic activities if they have fibrous union.