Degenerative Joint Disease

"Chinook"

“Chinook” is a 5-year old spayed female Siberian Husky that was presented with a rear leg lameness of at least two months duration. Physical examination was uneventful except for the obvious lameness and noticeable pain on palpation of the right stifle (knee) joint. The owner noted that the lameness had become progressively worse over the last two weeks. Radiographs of the hips and rear limbs were recommended. A reversible sedative, Domitor, was given which relaxed “Chinook” sufficiently so that diagnostic radiographs could be taken. The sedation also allowed her joints to be palpated revealing no abnormal looseness such as that caused by ruptured internal ligaments. The patella (kneecap) did move about abnormally.

The radiographs revealed normal hips but severe degenerative joint disease (DJD) of the right stifle joint. The bone on both sides of the joint was remodeled and thickened (A). There were fragments of calcified bone and cartilage inside the joint itself (B) as well as collapse of the joint cartilages and narrowing of the joint cavity (C). The patella (kneecap) was luxated (dislocated) and very misshapen and remodeled.

The first drawing depicts a normal knee with the patella in place with its tendon centrally located on the front of the joint. The second drawing shows a luxated (dislocated) patella which as shifted medially (toward the inside of the leg) revealing the patellar groove that it normally rides in. The damage to this joint is permanent. “Chinook” will always have problems with it, although sometimes substantial relief can be achieved with medication. “Chinook” was placed on an NSAID (non-steroidal antiinflammatory drug) called Rimadyl (Pfizer). This is one of the safest and most effective non-cortisone antiinflammatory drug available for dogs. “Chinook” is doing very well as a result.