Texas Equine Veterinary Association

www.teva-online.org • Page 26 5); however, they can occasionally be observed in the distal humeral condyle. Much like stifle cysts of the medial femoral condyle, there is commonly articular communication through a cloaca. Degree of lameness is highly variable and often fluctuates with use. There are usually no definitive signs that localize the lameness to the elbow. Palpation of the caudal and lateral joint pouch of the elbow may reveal some excess fluid; however this is not always consistent. Elbow extension and flexion often worsen the lameness. Localization requires confirmation of improvement in lameness following elbow joint intrasynovial anesthesia. Definitive diagnosis requires radiographic verification of the cyst via medial-to- lateral and cranial-to-caudal radiographs. Treatment is variable and highly dependent on the pathology present within the elbow. Conservative management consists of prolonged rest and administration of systemic and intra- articular, anti-inflammatory therapy. 10,11 Stall rest and controlled exercise is recommended for approximately 90 days. Following rest, it is important to re-evaluate for lameness to determine if exercise can be increased or if surgical treatment is required. Prognosis for conservative management of subchondral cysts appears good as long as there is no radiographic evidence of secondary arthritis. Surgical management is highly dependent on the location of the lesion. Subchondral and articular cartilage defects of the distal humerus are sometimes accessible arthroscopically and can be surgically debrided. 12 In contrast, subchondral and articular cartilage defects of the proximal radius are not accessible arthroscopically. Proximal radius cysts can be drilled and the contents of the cyst extirpated from a periarticular approach (Figure 6). Clinically, periarticular drilling of elbow subchondral cysts appears to result in less long-term evidence of secondary degenerative joint disease when compared to conservative management. In general, if economics prevent surgical management and/or no osteoarthritis signs are present, treat conservatively. It is very important to re-evaluate these patients frequently to assess for development of secondary osteoarthritis. If secondary osteoarthritis develops and is rapidly progressing, then surgical intervention is recommended. concLusIon While elbow lameness is quite uncommon, this is a fairly comprehensive review of pathology that can cause lameness. Performing the appropriate diagnostics and confirmation with intrasynovial anesthesia will help aid in determination of the appropriate treatment options. RefeRences 1. Moyer W, Schumacher J, Schumacher J. A guide to equine joint injection and regional anesthesia. Veterinary Learning Systems, Yardley, PA. 2007. 2. Mez JC, Dabareiner RM, Cole RC, et al. Fractures of the greater tubercle of the humerus in horses (15 cases). J Am Vet Med Assoc 12:1878. 2000. 3. Dyson S. Interpreting radiographs. Radiology of the equine shoulder and elbow. Equine Vet J. 5:352. 1986. 4. Watkins JP. Radius and Ulna (2012). In J Auer, J Stick (Eds.). Equine Surgery (1363-1378). St. Louis, Mo. Saunders Elsevier. Figure 4. Example of a complete luxation with concurrent ulnar and small caudal radial fracture fragment (Monteggia Fracture). The fracture was repaired with open reduction and internal fixation resulting in a horse that was able to return to its intended use. (Photo courtesy of Dr. Jeffrey P. Watkins, Texas A&M University) Figure 5. Small subchondral bone cyst located on the medial aspect of the proximal radius. Proximal to the cyst there is also a subchondral defect of the distomedial humeral condyle. The cyst is inaccessible through the joint; however, the defect of the distal humerus is likely accessible arthroscopically.

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