Ununited aconeal process of the elbow refers to a portion of bone at the back of the elbow joint which fails to fuse during development and growth. This fragment of bone is large and causes significant lameness and pain the elbow joint when it becomes detached.
The condition is diagnosed in young, rapidly growing, large breed dogs, with patients usually being diagnosed under 12 months of age. A second group of patients are diagnosed later in life, should the fragment become displaced after initially being stable. The large mobile fragment and abnormal wear of cartilage within the joint lead to the progression of debilitating osteoarthritis and ongoing joint pain. The diagnosis of an ununited acaoneal process within the elbow is based on clinical examination and presence of a fragment seen on x-rays.
Treatment choice depends, in part, on the age of the patient at the time of diagnosis. Patients diagnosed under 12 months of age with normal appearing fragments are candidate for reattachment of the fragment using a screw, and cutting of the bone at the back of the elbow to relieve tension across the fragment. Patients older than 12 months, or those with abnormal appearing fragments, are candidates for complete removal of the fragment.
The prognosis for resolution of the lameness and return to function is reasonable, despite the progression of significant osteoarthritis, but considerably better than those patients who are left untreated.
Long-term options for the management of elbow dysplasia are based on maintenance of lean boy condition, physiotherapy, joint supplementation (fish oils, glucosamine, chondroitin, pentosane polysulphate injection), joint anti-inflammatories and exercise moderation.