Abstract
Arthroscopic procedures have become a standard diagnostic and therapeutic option for canine joint disorders in recent years. Currently, arthroscopy is used routinely and frequently to examine canine elbow for elbow dysplasia [medial coronoid disease (MCD) or fragmentation medial portion of coronoid process (FCP)], canine shoulder for osteochondrosis dissecans (OCD) and biceps tenosynovitis, and canine stifle for rupture of cranial cruciate ligament (CrCL) and meniscal injuries.
Indication
The advantages of arthroscopy over open arthrotomies are well documented. Arthroscopy provides excellent visualization and access to the joint, with a minimally invasive approach. Therefore, arthroscopic surgery may result in better diagnostic accuracy, less patient morbidity, shorter anesthetic and surgery times, lower complication rates, shorter hospital stays, and more rapid and functional recoveries. The disadvantages primarily involve the expertise and equipment required to perform arthroscopic surgery at an appropriate level. Arthroscopic equipment and special instruments can be expensive ($50,000–200,000), and arthroscopic procedures can be difficult and may require lengthy training and experience up to a few years.
Elbow Dysplasia
In small animal orthopedic surgery, exploration and treatment of the canine elbow dysplasia is likely the most common application of arthroscopy. Among different types of elbow dysplasia, fragmentation of medial portion of coronoid process (FCP) (or medial coronoid disease (MCD)) is the most frequent and important indication of arthroscopy. Other forms of elbow dysplasia [OCD, ununited anconeal process (UAP), ununited medial epicondyle (UME), and elbow incongruity] can be also visualized and treated via arthroscopy, although its role is significantly less compared with its role in FCP/MCD.
FCP/MCD
FCP/MCD is a congenital and developmental condition commonly seen in large breed dogs. Unlike other forms of elbow dysplasia (OCD and UAP), FCP can be extremely difficult to diagnosed with routine radiography. CT scan can be utilized to diagnose FCP; however, subtle cartilaginous legions can be missed with CT. Arthroscopy allows direct visualization of diseased coronoid process, and therapeutic procedures including removal of fragment, curettage of subcondral bone, or subtotal coronoidectomy. Because of these advantages, arthroscopy is now considered "a gold standard" for FCP treatment. Elbow OCD can be treated arthroscopy in a similar way.
Shoulder Arthroscopy
Canine shoulder can also be explored and treated arthroscopically. Shoulder OCD is a congenital and developmental problem commonly seen in large breed dogs. Arthroscopy eliminates a necessity of extensive and invasive open approach to the caudal part of shoulder. In mature active dogs, shoulder tenopathy can be a cause of thoracic limb lameness. Shoulder arthroscopy allows direct visualization of biceps tendon, subscapularis tendon, and glenohumeral ligament. Arthroscopic biceps release procedure can be an effective treatment for canine biceps tenosynovitis.
Stifle Arthroscopy
Canine stifle arthroscopy is valuable in diagnosing partial rupture of CrCL and meniscal tears. Its application has been limited mainly due to 1) necessity of more aggressive surgical procedure (lateral fabello-tibial extracapsular suture, TPLO, TTA) on top of arthroscopy, and 2) technical difficulty. Stifle arthroscopy provides excellent visualization of subtle CrCL tear superficial lesion of caudal cruciate ligament, condylar cartilage fibrillation, and dynamic meniscal tear.
Other Applications
Tarsal arthroscopy has been used to treat tarsal OCD, and hip arthroscopy has been used to evaluate cartilage health in canine hip dysplasia; however these applications are much less common compared with elbow/shoulder/stifle arthroscopy. Arthroscopy has been also occasionally used in feline joints.
Limitations
Arthroscopy in small animal orthopedics has numerous theoretical benefits. However, its use is still limited mainly due to technical difficulties in small joints. In addition, there is no conclusive evidence that demonstrates significant advantages of arthroscopy in small animal orthopedics over conventional arthrotomy.