Developmental orthopedic diseases: etiology and possible effects of nutrition and exercise

At its birth, the neonatal foal is subjected to very profound changes. These changes not only concern the respiratory and digestive tracts, but also the musculoskeletal system. The biochemical make-up of the collagen network within the extracellular matrix of articular cartilage shows a distinct topographical variation that is formed under the influence of exercise during early life. This is an important process as it will determine the ultimate quality, and hence the injury resistance, of the cartilage as this tissue is known to be unable of substantial change in the mature individual due to its low metabolic rate. In osteochondrosis two different processes should be discerned: the (multifactorial) pathogenesis of lesions and the ensuing repair process. The latter process is determined by the metabolic level of the cartilage extracellular matrix. Early lesions that are not too large may be repaired completely (and thus disappear on radiographs), but the declining metabolic level may preclude full repair of later lesions that eventually may turn into lesions that can become of clinical importance.