Elbow dysplasia is a broad term that encompasses four abnormal conditions: ununited anconeal process (UAP), fragmented medial coronoid process (FMCP), osteochondritis dissecans of the medial humeral condyle (OCD) and ununited medial epicondyle (UME).
- UAP is characterized by failure of the fusion of the anconeus with the alecranon by 5 months of age. It affects mostly large-breed dogs.
Treatment consist in removing the ununited fragment from the joint. Occasionally patients are candidates for screw fixation of the fragment.
- FMCP is characterized by failure of the cranial portion of the coronoid process to fuse with the main portion of the coronoid process. Movement of the loose coronoid fragment inflames the joint and causes damage to the opposite joint surface, the medial humeral condyle.
Treatment consists in removing the fragment. Often time the remaining portion of the medial coronoid process is causing excessive pressure against the opposing articular surface of the medial humeral condyle and needs to be “shaved” or removed (subtotal coronoidectomy).
- OCD of the medial humeral condyle is characterized by detachment of an area of articular cartilage from the underlying bone of the humeral condyle. It is often found in association with FMCP.
Treatment consists in removing the cartilage flap and irritating the underlying bone to promote the growth of fibrocartilage to fill the defect.
- UME is a very rare condition characterized by failed fusion of part of the medial humeral epicondyles.
Treatment consists of resecting the detached fragments.
All patients having undergone surgery for any form of “Elbow dysplasia” must be limited to moderate, controlled exercise (leash walked) for 6 weeks post-surgery.
Patients with UAP and FMCP should be examined 5-6 weeks following surgery to assess the amount of fluid in their elbow joint. Patients with excessive fluid accumulation should have the excess fluid removed by inserting a needle in the joint under local anesthesia and a small dose of steroid (cortisone) injected in this elbow joint and remain on limited activities for an additional month.