The most common injury to a dog’s knee is an ACL tear, which stands for anterior cruciate ligament tear. In dogs, the more correct term is cranial cruciate ligament tear or rupture, CCLR. This is simply because of the fact that dogs walk on all fours instead of upright, but the ligament is the same and serves the same function regardless of what it is called.
The ACL attaches at the rear of the femur, and crosses to the front of the knee to attach to the front of the tibia. It’s function is to prevent abnormal forward movement of the tibia relative to the knee joint. When torn, a veterinarian may be able to demonstrate this forward movement, called a drawer sign upon physical examination.
A pet that has torn it’s ACL may suddenly become non weight bearing lame on a rear leg, or may only toe touch with that leg. If left alone, the pet seems to improve in a week or two, but this is simply because the body starts to make changes to the knee joint to try to stabilize it. There are usually significant arthritic changes that occur if the torn ligament is not repaired. In addition, dogs that tear one ligament are more likely to tear the other one, so repairing the first tear to prevent additional strain on the non-torn ligament is recommended.
There are a number of different methods to repair a torn ACL. The choice is based on the pet’s age, activity level, degree of arthritis, size, and other factors. Options for repair include:
- Extracapsular repair
- TPLO, or tibial plateau leveling osteotomy
- TTA, or tibial tuberosity advancement
After surgery, anti-inflammatory pain medications or NSAIDs are often used. Long term use of glucosamine and chondroitin are often recommended. Rehabilitation exercises and restrictions of activity may be recommended as well. Keeping the pet at a lean weight helps decrease strain on the joints.
If your pet has injured their knee, a veterinarian visit is in order. X-rays or radiographs may be recommended, and if a torn ACL is diagnosed, a discussion with the specialty surgeon and your pet’s lifestyle will determine which type of surgery will be recommended. Together we can help your pet regain as much function as possible and decrease the likelihood of arthritis in the future. Call us today to discuss the options available to your pet!