OSTEOCHONDROSIS OF THE FEMUR

Osteochondrosis is a developmental disorder affecting cellular differe ntiation of physeal cartilage cells in dogs.(9,13-15,18,19) Common sit es of occurrence include the humeral head in the shoulder joint and th e medial aspect of the humeral condyle in the elbow joint. Lesions can occur less frequently on the trochlear ridges of the talus in the tib iotarsal joint and on the femoral condyles in the stifle joint. In a r etrospective review by the author of 52 cases diagnosed radiographical ly or surgically as osteochondrosis from November 1991 through July 19 96 at a rural university teaching hospital (Washington State Universit y, Pullman, WA) and an urban general and referral hospital (Rowley Mem orial Animal Hospital, Springfield, MA), only four (8%) patients with osteochondrosis had stifle joint lesions. Initially identified in 1959 , osteochondrosis of the stifle joint has been sporadically described in clinical reports from Europe, Australia, and the United States duri ng the 1970s and 1980s.(1,4,8,12) The largest case numbers of patients (103) were described in a 9-year review and a longterm (> 1 year) fol low-up of affected dogs in Austria.(3) Osteochondrosis of the coxofemo ral joint involving the head of the femur is extremely rare.(7,10) In this article, osteochondrosis of the femur will be discussed with rega rd to cause(s), diagnosis, and treatment.