PETS :: OCTOBER/NOVEMBER 2007
Stifle (knee) Injuries in Dogs and Cats
One of the most common causes of rear limb lameness in dogs is rupture of
the cranial cruciate ligament (CCL) within the stifle joint. The stifle is stabilized
by many ligaments and muscles. Of particular interest, the CCL prevents the
tibia (bottom of the joint) from displacing forward in relation to the femur
(top of the joint) during the weight bearing phase of walking. This disease
also occurs in cats but is much less common. The term injury is actually a misnomer,
since a traumatic event is rarely the cause of a CCL rupture in dogs. In most
cases, the cause of the rupture is a gradual deterioration of the ligament over
time, until the ligament finally ruptures. The deterioration is specific to
the cranial cruciate ligament and the definitive cause is unknown. In 50% of
dogs with a CCL rupture in one stifle, it will also eventually occur in the
other stifle in the future.
Rupture of the CCL usually results in a sudden severe lameness. In some cases,
the ligament develops small tears without a complete rupture. This is termed
a partial CCL rupture. These dogs tend to have a less severe lameness and the
lameness may be intermittent.
Surgery generally results in the best outcome. How-ever, in some cases the outcome is acceptable without surgery. Small dogs (less than 15 lbs) and cats are more likely to have an acceptable outcome without surgery than large dogs. Physical therapy has also been shown to aid in recovery from CCL ruptures.
Surgeries for CCL ruptures fall into 2 main categories: static vs dynamic repair. Static repair techniques involve using a synthetic material or another ligament/tendon to replace the cranial cruciate ligament. Unfortunately, synthetic materials and ligament/tendon grafts usually “wear out” over time and break. In many cases, the stifle has stabilized itself by the time the surgical repair fails. In some cases, however, the stifle stability is completely lost once surgical repair fails. Many of these cases continue to have a chronic intermittent lameness.
Recently, newer techniques (dynamic repair) have been developed to treat CCL ruptures. These surgeries do not replace the ligament, but rather change the geometry of the stifle so that the ligament is no longer necessary. Therefore, we do not have to be concerned with the replacement ligament breaking in the future. These surgeries are becoming very common in veterinary medicine and show great promise for a marked decrease in lameness. I prefer a technique called the tibial tuberosity advancement (TTA). In my experience, this procedure tends to provide consistently good results and allows animals to start using the leg much quicker than the static techniques.
In all cases of cranial cruciate ligament rupture, some irreversible arthritis will develop irregardless of treatment. Therefore, these patients may always intermittently need pain medication. However, most animals will still have a very good quality of life after recovery.
Dr. James Winkler recently joined the staff at Windcrest Animal Hospital to provide advanced surgery procedures. He is a graduate of North Carolina State University Veterinary School. Dr. Winkler completed a Small Animal Rotating Internship and Small Animal Surgery residency at Auburn University Veterinary Medical School. Dr. Winkler obtained a master’s degree in veterinary sciences during his residency. He became a diplomate of the American College of Veterinary Surgeons in 2003. Dr. Winkler has a wide variety of interests in the fields of neurologic, orthopedic, reconstructive, soft tissue, and oncologic surgery. He has two young boys, Peter and Liam as well as two horses- Red and Blue and dogs Buzz and Axel.
WINDCREST ANIMAL HOSPITAL
3705 Lancaster Pike
Wilmington, Delaware 19805
(302) 998-2995
24 Hour Emergency
TALLEYVILLE VETERINARY HOSPITAL
3001 Concord Pike
Wilmington, Delaware 19803
(302) 478-0648
HOCKESSIN ANIMAL HOSPITAL
643 Yorklyn Road
Hockessin, Delaware 19707
(302) 239-9464
