X-ray examination signs of cat joint disease, the disease makes cats miserable! The cat's joint disease will break out slowly with age, and the causes of joint disease are divided into Congenital and acquired causes, the specific diagnosis also needs to use some auxiliary means such as X-ray examination to confirm the diagnosis. In the radiographic examination of joint diseases, different symptoms have different appearances, and we need to identify them.

1. Changes in articular surfaces

Unsmooth articular cartilage and the underlying bony articular surface bone are eroded and replaced by pathological tissue, resulting in joint destruction and uneven articular surface. In the early stage of the disease, when only the articular cartilage is destroyed, the joint space is narrowed, and the bony articular surface is damaged, which is eroded and rough or has obvious defects. More common in the late stage of suppurative joint inflammation, degenerative joint disease and so on.     

Joint border ossification There is new bone growth around the articular surface, forming joint lips or joint osteophytes. More common in degenerative osteoarthritis, tendon, ligament insertion point ossification. A shadow in the subchondral bone of the articular capsule cavity with a circular or quasi-circular defect area with a clear edge, communicating with or not communicating with the joint cavity, is called a bone cyst.

Fracture of the articular surface, cracks in the articular surface, or large defect in the articular bone. Seen in intra-articular fractures or bone end fractures.

Second, changes in joint space

The widening of the joint space is caused by a large amount of effusion in the joint due to inflammation, and the swelling of the joint capsule and the widening of the joint space can be seen. Such lesions are more common in various effusion arthritis and joint diseases.

Joint space narrowing When joints undergo degenerative changes, articular cartilage degenerates, necroses, and dissolves, causing joint space narrowing, More common in the late stage of septic arthritis, degenerative joint disease and so on.

The width of the joint space is uneven. When the supporting ligaments of the joint, such as the lateral ligament, are ruptured, the joint loses its stability. An X-ray image that is wide on one side and narrow on the other.

The disappearance of the joint space is mostly the X-ray manifestation of osseous connection of the joint, that is, the ankylosis of the joint. When the joint is obviously damaged, the bone ends of the joint are connected by bone tissue, resulting in bony healing. More common in acute suppurative arthritis after healing, degenerative joint disease.

The result of intra-articular fracture of foreign body in the joint space is that the fracture fragment is free in the joint cavity, and high-density bone images appear; External foreign bodies can enter the joint cavity during the trauma, and foreign body shadows can be seen; when the joints are infected with gas-producing bacteria, air shadows appear in the joint space.

III. Changes of extra-articular soft tissue shadows

Swelling is mainly caused by inflammation of the joints. Due to joint effusion or hyperemia, hemorrhage, edema and inflammatory exudation of the joint capsule and its surrounding soft tissue, the soft tissue around the joint is swollen, and the extra-articular soft tissue shadow, density and structure are unclear on X-ray films.

Atrophy, atrophy of extra-articular soft tissue can cause the shadow of extra-articular soft tissue on X-ray to shrink and its density to decrease. Such lesions are often seen in joint disuse, such as long time of fracture fixation.    

Open injury to the joint with foreign body in the soft tissue, the foreign body enters the soft tissue, and air shadow appears in the shadow of the extra-articular soft tissue or shadows of foreign objects. The avulsion fracture of the bony shadow joint capsule or joint ligament and the ossification of the muscle, tendon, ligament or joint capsule at the articular bone insertion point will cause a high-density bony shadow within the shadow of the extra-articular soft tissue.