|Radiography and histology of the centrodistal tarsal joint of Icelandic horses
Osteoarthrosis (OA) in the distal tarsal joints, bone spavin, is a common problem in Icelandic horses which are 6-12 years old. This very interesting study determines nature, location and age of appearance of early radiographic and histological changes in the centrodistal tarsal joint (CD) of young Icelandic horses.|
|Slab sections from the CD of young Icelandic horses were examined by high detail radiography (age 6 months to 6 years, n = 111) and histology (age 6 months to 4 years, n = 82) to detect and describe the early changes indicative of OA. Horses younger than 5 years were unridden.
Chondronecrotic lesions histologically similar to those described in the early pathogenesis of OA were seen in 33% of the joints, located both medially and laterally.
Radiographic sclerosis of the subchondral bone was recorded in 60% of the specimens, most often medially.
Medial location was not associated with chondronecrosis, but was strongly related to age. Sclerosis was an infrequent finding on the lateral side, and was probably secondary to chondronecrosis in the corresponding part of the joint.
Small defects in the subchondral bone were considered to be the most specific radiographic sign of OA as they were strongly associated with chondronecrosis.
CONCLUSIONS: The high prevalence of chondronecrosis in the young horses indicates an early onset and slow progression of the disease. The early appearance also shows that the initiation of the disease is unrelated to the use of horses for riding.
As clinical manifestation of OA in the distal tarsal joints is most often described in mature or old horses, the first stages of the disease are not likely to result in clinical signs. Subchondral bone sclerosis did not appear to be a primary factor in the development of OA in the CD but was considered to reflect an uneven distribution of biomechanical forces within the joint.
The development of OA in the CD of young Icelandic horses seems to be due to poor conformation or joint architecture rather than trauma or overloading. These aetiological factors are likely to be of importance for OA in the distal tarsal joints in other breeds as well.
The influence of hindlimb conformation and the architecture of the distal tarsal joints on the biomechanics of joints need to be investigated, preferably by locomotion analysis in young horses.
Source: Bjornsdottir S, Ekman S, Eksell P, Lord P. (2004): High detail radiography and histology of the centrodistal tarsal joint of Icelandic horses age 6 months to 6 years. In: Equine Vet J. 2004 Jan;36(1):5-11
Tell a friend
Send this article
Unusual cause of unilateral facial swelling in a coltNovel topical therapy of equine sarcoidsConventional radiography versus CT to diagnose osteomyelitis in foalsNovel surgical treatment of recurrent laryngeal neuropathy in horses Standing repair of a fracture of the third metatarsal bone of a Hunt Thoroughbred mare Unusual cause of bilateral blindness in a young Quarter HorseAdvanced imaging of an incomplete fracture of Os metacarpale III in a young WarmbloodEquine external beam radiation therapyInsulin dysregulation in horses with SIRSThe farrier role in supporting horse owners to prevent laminitisCT description of equine oromaxillary sinus and oronasal fistulaeInsulin and the structural integrity of equine digital lamellae