Osteochondrosis


Osteochondrosis is a family of orthopedic diseases of the joint that occur in children, adolescents and other rapidly growing animals, particularly pigs, horses, dogs, and broiler chickens. They are characterized by interruption of the blood supply of a bone, in particular to the epiphysis, followed by localized bony necrosis, and later, regrowth of the bone. This disorder is defined as a focal disturbance of endochondral ossification and is regarded as having a multifactorial cause, so no one thing accounts for all aspects of this disease.

Signs and symptoms

These conditions nearly all present with an insidious onset of pain referred to the location of the bony damage. Some, notably Kienbock's disease of the wrist, may involve considerable swelling, and Legg-Calvé-Perthes disease of the hip causes the victim to limp. The spinal form, Scheuermann's disease, may cause bending, or kyphosis of the upper spine, giving a "hunch-back" appearance.

Cause

The ultimate cause for these conditions is unknown, but the most commonly cited cause factors are rapid growth, heredity, trauma, anatomic conformation, and dietary imbalances; however, only anatomic conformation and heredity are well supported by scientific literature. The way that the disease is initiated has been debated. Although failure of chondrocyte differentiation, formation of a fragile cartilage, failure of blood supply to the growth cartilage, and bone necrosis all have been proposed as the starting point in the pathogenesis, recent literature strongly supports failure of blood supply to growth cartilage as most likely.

Diagnosis

Classification

In humans, these conditions may be classified into three groups:
  1. Spinal: Scheuermann's disease which is a curve in the thoracic spine.
  2. Articular: Legg-Calvé-Perthes disease, Köhler's disease, Panner's disease, and Freiberg's infraction
  3. Non-articular: This group includes Sever's disease, and Kienbock's disease of the hand, and other conditions not completely characteristic of the osteochondrosis, such as Osgood-Schlatter's disease and Osteochondritis dissecans.

    Prognosis

The term osteochondrosis has been used to describe a wide range of lesions among different species. There are different types of the prognosis: latens, which is a lesion restricted to epiphyseal cartilage, manifesta, a lesion paired with a delay in endochondral ossification, and dissecans which is a cleft formation in the articular cartilage.
The prognosis for these conditions is very variable, and depends both on the anatomic site and on the time at which it is detected. In some cases of osteochondrosis, such as Sever's disease and Freiberg's infraction, the involved bone may heal in a relatively normal shape and leave the patient asymptomatic. On the contrary, Legg-Calvé-Perthes disease frequently results in a deformed femoral head that leads to arthritis and the need for joint replacement.