Canine Arthroscopy - Where less really is more.

Arthroscopy has proven to play a significant role in the diagnosis and treatment of joint diseases in humans, horses, and most recently dogs.  Arthroscopy allows enhanced visualization of intra-articular structures and is associated with limited postoperative morbidity.  Nowadays, arthroscopy has replaced virtually all arthrotomies in human patients.  Arthroscopy has only become possible in dogs since the development of small-sized arthroscopes.  Arthroscopy in dogs was first reported in 1978 and has seen an increasing level of interest and rapid development since that date.  Small animal veterinary surgeons are currently capable of performing arthroscopic procedures on the stifle, shoulder, elbow, hip, and carpal and tarsal joint. 

Arthroscopy has numerous advantages over arthrotomy for diagnosis and treatment of joint disease.  Arthroscopy entails less disruption of the periarticular soft tissue.  Decreased soft tissue disruption leads to less pain and less chance of infection.  In most cases, return to use of the limb is quicker because of less surgically induced pain.  This is especially true when multiple joints are involved and are operated arthroscopically under the same anesthetic procedure.  A recent study by Hoelzler MG, et.al., published in Veterinary Surgery, compared stifle arthrotomy to arthroscopy.  Results of this study revealed a significant decrease in lameness, more comfortable range of motion, increased thigh circumference, and decreased synovial fluid inflammation in dogs treated with arthroscopy compared to those treated with an arthrotomy.

Arthroscopy may be employed in a diagnostic, therapeutic or combined modality.  Using arthroscopy as an exploratory procedure may prevent the necessity for an arthrotomy and is an important advantage in cases where a surgically treatable lesion is not found.  Visualization of the joint typically is better with arthroscopy than with an arthrotomy.  In joints like the shoulder and elbow, arthroscopy allows inspection of multiple areas within the joint that would not otherwise be possible without performing multiple arthrotomies.  In addition, the magnification combined with the fluid medium allows one to see joint pathology that cannot be appreciated with an arthrotomy.  Visualization of synovial membrane and cartilage pathology, in particular, is better after arthroscopy compared to arthrotomy.  With practice and development of proficiency, the length of an arthroscopic procedure is less than an arthrotomy procedure.  Cosmetic appearance of the dog is typically better after arthroscopy compared to arthrotomy.  For many owners, cosmetic appearance is very important.

Disadvantages of arthroscopy are that its use is limited to large dogs, the equipment is expensive, and considerable training is needed to become proficient with its use.  Depending on the specific joint, the dog must be at least 45 pounds or 20.5kg before an arthroscopy can be performed.  Even though the price of arthroscopy equipment is decreasing, one can easily spend $20,000 – $50,000 for the equipment and instrumentation.  Arthroscopy requires considerable practice, advanced hand-eye coordination and needs to be performed on a regular basis to be performed proficiently.

VOSM's surgeons have received extensive training in arthroscopy and are skilled at performing arthroscopic procedures for the diagnosis and treatment of diseases of the shoulder, elbow, stifle, and hock.  Diagnostic and therapeutic arthroscopic procedures in the shoulder include; osteochondritis dissecans (OCD), bicipital tenosynovitis, glenoid fractures, joint laxiety (glenoid humeral ligament tears).  Arthroscopic procedures of the elbow include:  OCD, fragmented medial coronoid process, an ununited anconeal process, and debridement of chronic osteoarthritic changes.  Arthroscopy of the stifle include:  OCD, diagnosing partial cranial cruciate ligament ruptures, debriding meniscal tears and ruptured cruciate ligament remnants prior to an extracapsular stabilization or the tibial plateau leveling osteotomy (TPLO), and performing the meniscal release prior to the TPLO.  Arthroscopy of the hock is limited to the diagnosis and treatment of OCD.

In the developmental stage of arthroscopy in the dog, a frequently expressed comment was that arthrotomy was as valuable and as easy (or easier) to perform as arthroscopy.  Now that the advantages of arthroscopy have been demonstrated, the skepticism has changed into enthusiasm.  The same evolution occurred with arthroscopy in both humans and the horse. 

References:

• Cook JL, Tomlinson JL, Stool MR, et al.  Arthroscopic removal and curettage of osteochondrosis lesions on the lateral and medial trochlear ridges of the talus in two dogs.  J Am Anim Hosp Assoc 2001; 37:75-80.
• Van Bree HJ, Van Ryssen B.  Diagnostic and surgical arthroscopy in osteochondrosis lesions.  Vet Clin North Am Small Anim Pract 1998; 28(1):161-89.
• Abercromby R.  Examination of arthroscopy as a clinical tool in small animal practice.  J Sm Anim Pract 1997; 38:174-78.
• Lewis DD, Goring RL, Parker RB, et al.  A comparison of diagnostic methods used in the evaluation of early degenerative joint disease in the dog.  J Am Anim Hosp Assoc 1987; 23:305-315.
• Hoelzler MG, Millis DL, Francis DA, et al.  Results of arthroscopic versus open arthrotomy for surgical management of cranial cruciate ligament deficiency in dogs.  Vet Surg 2004;33:146-153.