Spondylose

nicht entzündliche, degenerative Erkrankung an den peripheren Endplatten der Wirbelkörper mit Knochenzubildung

viele Studien unterscheiden nicht zw. DISH und Spondylosen

Radiologie: kleine Osteophyten bis Knochenbrücken über den Intervertebralspalt

Spondylosis is diagnosed on radiographic (Figure 1) or histopathological examination. Using radiographs, a distinction has been made between end-plate osteophytes (type 1) described to be the result of spondylosis, and a group of three other types (types 2, 3 and 4) of new bone formation. The spurs of type 2 and 3 have, compared to type 1, a broader base of origin at the vertebral body and grow out to be type 4, which consists of a contiguous ventral band of new bone (Figure 2). These last three types were described to be comparable with those seen in human diffuse (or disseminated) idiopathic skeletal hyperostosis (DISH), formerly called ankylosing hyperostosis. Most other studies of canine vertebral hyperostosis did not specifically distinguish between spondylosis and DISH. In these studies, all bridging ossifications were thought to be severe spondylosis. Dogs diagnosed with spondylosis have been subdivided into three subclasses according to the degree of osteophytes development. In grade 1, the bony spur does not protrude beyond the caudal/cranial edge of the vertebral border, in grade 2 it does protrude beyond the caudal/cranial edge of the vertebral border, and in grade 3, a bony bridge is formed from the corner of one vertebra to the next (Figure 1). It has been proposed that in the past DISH in dogs was possibly described as a severe variant of grade 3 spondylosis. Although radiographic differentiation between DISH and severe spondylosis may be challenging, the two disorders do differ in radiographic appearance.

The prevalence of canine spondylosis increases with age, with a described breed predilection for Boxers. In Norwegian Boxers, a prevalence of 26% (104/402) of spondylosis was found. In Italian Boxers, an even higher prevalence (50%) of grade 3 spondylosis was reported. The prevalence and the degree, or grade, of spondylosis were described to increase with age.

In cats a high prevalence of spondylosis is also reported. In the 1960s prevalence ranging from 34–68% was reported. In 55 out of 100 cats more than one site of the axial column was affected. The caudal thoracic region, cranial lumbar region and the lumbosacral region were reported to be most often affected by spondylosis. Spondylosis in the cervical spine is described less often. In cats, spinal segments T4–T10 are described to be most frequently affected by spondylosis. More extensive new bone formation was found more frequently in the caudal part of the vertebral column.

Clinical signs reported to be related to severe canine spondylosis are stiffness in the back, lameness, changes in gait and pain. In working dogs the diminished spinal flexibility limits activity. Osteophyte formations extending dorsolaterally can incidentally compress spinal nerve roots at the level of intervertebral foraminae. Spondylosis was also detected on computed tomography (CT) images in 62% of dogs with degenerative lumbosacral stenosis (DLS). Although the presence of spondylosis has been suggested to be correlated with Hansen's type 2 disc protrusion, spondylosis is also found in combination with healthy intervertebral discs. Generally, spondylosis has been described not to be of great clinical relevance in dogs. In cats, the spondylosis-associated changes of the intervertebral junction, a cartilaginous joint, are dissimilar to those associated with osteoarthritis of synovial joints. Nevertheless, both osteoarthritis and spondylosis are considered as part of degenerative joint disease and are suggested to be a possible overlooked cause of clinical disease in cats. Cats are known to mask signs of skeletal pain and often adjust their behaviour as a coping mechanism.

When only pain and stiffness are reported, most veterinarians in general practice start out with a conservative treatment similar to that for degenerative osteoarthritis (arthrosis), which consists of bodyweight reduction, controlled exercise or physiotherapy and non-steroidal anti-inflammatory drugs (NSAIDs).

Meij B (2012): Spondylosis and Spinal Abnormalities: When Are They Relevant? WSAVA/FECAVA/BSAVA World Congress 2012.