Musculoskeletal System
Bone - Osteochondrosis
Narrative
Osteochondrosis occurs in a variety of domestic species, primarily as a lesion of young, rapidly growing animals, and is thought to be influenced by dietary, hormonal, anatomic, and genetic factors. Osteochondrosis occurs as a spontaneous lesion in aged rats, although lesions may sporadically occur earlier in life. Early histologic evidence of osteochondrosis includes thickening or fragmentation of the basal layer of articular cartilage and may be observed in Sprague-Dawley rats as early as six weeks of age. This lesion tends to occur in regions of articular cartilage that are thicker, such as the caudal aspect of the medial femoral condyles and humeral head. Lesions of osteochondrosis are focal in nature, although they may occur multifocally or bilaterally in the same animal.
Historically, osteochondrosis has also been recorded as osteochondritis and osteochondritis dissecans. The term "osteochondritis" is not appropriate since inflammation is not a characteristic feature of the lesion. The term "dissecans" is inappropriate since it implies cleft formation through the articular cartilage, while osteochondrosis is a spectrum of histologic features, cleft formation being an end-stage or progressed manifestation.
Kato M, Onodera T. 1984. Spontaneous osteochondrosis in rats. Lab Anim 18:179-187.
Abstract: http://www.ncbi.nlm.nih.gov/pubmed/6748595Kato M, Onodera T. 1987. Early change of osteochondrosis in medial femoral condyles from rats. Vet Pathol 24:80-86.
Abstract: http://www.ncbi.nlm.nih.gov/pubmed/3824825Kato M, Onodera T. 1988. Morphologic investigation of osteochondrosis induced by ofloxacin in rats. Fundam Appl Toxicol 11:120-131.
Abstract: http://www.ncbi.nlm.nih.gov/pubmed/3209010Leininger JR, Riley MGI. 1990. Bones, joints, and synovia. In: Pathology of the Fischer Rat: Reference and Atlas (Boorman G, Eustis SL, Elwell MR, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, 209-226.
Long PH, Leininger JR. 1999. Bones, joints, and synovia. In: Pathology of the Mouse (Maronpot R, Boorman G, Gaul BW, eds). Cache River Press, St Louis, 645-678.
Long PH, Leininger JR, Ernst H. 1996. Proliferative lesions of bone, cartilage, tooth, and synovium in rats, MST-2. In: Guides for Toxicologic Pathology. STP/ARP/AFIP, Washington, DC.
Ytrehus B, Carlson CS, Ekman S. 2007. Etiology and pathogenesis of osteochondrosis. Vet Pathol 44:429-448.
Abstract: http://www.ncbi.nlm.nih.gov/pubmed/17606505