Elbow dysplasia in dogs - British Veterinary Association.

ED simply describes the abnormal development of the elbow (a dog's elbow iscircled below). The term includes a number of specific abnormalities, whichaffect different sites in the joint. They cause problems by affecting the growthof the cartilage which forms the surface of the joint, or the structures around it.These abnormalities, called primary lesions, then start a secondaryosteoarthritic process. The most common primary lesions are:• Osteochondritis dissecans (OCD or OD)• Fragmented or ununited coronoid process (FCP)• Ununited anconeal process (UAP)Examination of different radiograhic views allows detection ofabnormalitiesThe 'extended lateral 'position gives a view of thebones and joint surfaces ofthe elbow from the side. Inthis view, the position ofthe joint is similar to that inthe standing dogThe flexed lateral view is aside on view of the elbow.This view allowsexamination of thesecondary changes in EDwhich occur in the shadedareas. Note how some ofthe shaded areas here areoverlaid by otherstructures, which makesthem difficult to examineThe 'crani-caudal' view istaken from the front to theback of the joint and givesa totally different picture.Evidence of primarydisease, which cannot beidentified on the lateralview, is seen on this view.It also enablesconfirmation of secondaryabnormalitiesThere are other, more rare, primary lesions which may occur in combinationwith these, or on their own. Primary lesions occur during the growth of apuppy, and nearly always occur in both elbows to some degree.