The ACL (in humans) or CCL in dogs is a tough band of tissue that stabilizes the knee front to back. Both dogs and humans can injure or tear this ligament; however, treatment for the two species varies greatly. In humans, who have a vertical standing knee position, the ACL is mostly involved in stabilizing the knee when it is bent or flexed (in activities like jumping or running). Dogs have different anatomy; the normal standing angle of the dog’s knee is flexed, which means even STANDING requires the CCL to be intact.
Since the dog’s standing angle is flexed at about 135 degrees, the weight-bearing surface of the tibia (shinbone) is sloped backwards. When the CCL is torn, the femur (thighbone) slides backwards off the sloped tibia. This is the reason that your dog may literally be unable to bear weight in a standing position with this injury – the knee is unstable even in a standing position (let alone running or jumping). ANY abnormal unstable movement of the tibia relative to the femur of more than just a few millimeters can cause extreme pain and will eventually lead to arthritis.
Ligaments have limited blood supply, so injuries take MONTHS to heal. Partial or complete tears of the CCL may never fully heal, resulting in alternative measures to make the knee stable again. Additionally, CCL tears may cause the knee to become so unstable the meniscus (shock absorber of the knee joint) may also become torn, leaving a painful flap of cartilage inside the joint.
Conservative Management - heal strained or partially torn ligament, build up scar tissue and bone bridging to help stabilize total CCL tear
A) Strict Cage Rest
Stage 1: Strict cage rest for 6-8 weeks to allow as much scar tissue and bone bridging to form as possible to hopefully stabilize the knee. Anti-inflammatory medications are typically given through this period for pain and swelling inside the knee. This requires dedication from the family – STRICT cage rest means out for bathroom breaks and to eat only and on a leash. NO running, jumping, playing, stairs, or furniture.
Stage 2: After 2 months and clearance by one of our vets, begin slow controlled leash walks for up to 10 minutes twice a day. Slowly increase length of walks by 5 minutes each week. In between walks, there should still be no running, jumping, playing, stairs, or furniture – any explosive activity could set back recovery or cause a complete tear.
Stage 3: After you are up to 30-40 minutes of walking (should take ~6 weeks to build up to this) and doing well, you can start short (5-10 minute sessions) of controlled off leash play and gradually increase weekly until back to full activity, as long as the dog is not limping.
Stage 4: Long term, weight management is essential – dogs with recovered CCL injuries need to stay on the lean side to avoid catastrophic arthritis damage to the knee. Joint supplements (oral and/or injectable) are recommended for control of arthritis/scar tissue that will occur.
Supervised rehabilitation may occur at any/all stages of conservative management. Rehab can go a long way to a quicker recovery and less long term pain from arthritis. Swimming or Underwater Treadmill therapy have been shown to increase conservative rehabilitation by keeping muscles toned (muscles waste away quickly on cage rest) without putting weight bearing strain on the unstable knee. Options for local swimming therapy or underwater treadmill are included below.
Acupuncture and electro acupuncture (placing a micro electrical current between acupuncture needles, across the knee joint) have been shown to help decrease local inflammation and pain associated with a torn CCL. In addition, acupuncture can help to keep stimulating the muscles surrounding the knee in a low impact manner, helping to stabilize and balance the knee. One recent study suggested that electroacupuncture could even help protect against joint cartilage erosion in unstable arthritic knees! We offer acupuncture services here in our clinic – we ask that you try at least 3-4 sessions before deciding if it is helping your dog, as acupuncture can have a cumulative effect and can take up to 4 sessions before a large difference is seen. Acupuncture and electroacupuncture run $56 per session at our office.
Surgery – requires an orthopedic veterinarian. Consultation with an orthopedic surgeon typically runs ~$150 and sedated x-rays of the knee(s) in question typically run about $140 per knee.
A) Lateral Suture (aka “Tightrope Procedure”) - ~$2,000-2,500. A very strong suture (similar heavy weight fishing line) is placed to mimic the function of the CCL. In the short term, this should return stability of the knee artificially. The long term goal is to facilitate the scar tissue and bone bridging that will provide stability even if the suture stretches or breaks from repeated stress and flexing of the knee joint. This surgery is preferred in small breed dogs or older inactive dogs.
B) Tibal Plateau Leveling Osteotomy (TPLO) ~$300-5000. A circular cut is made in the bone around the top of the tibia (shinbone) and it is rotated so that the normal “backwards” slope of the tibia becomes almost level, stabilizing the knee in the absence of the CCL. The cut piece of bone is permanently held in place by attaching a metal plate and screws.
C) Tibial Crest Advancement (TTA) ~3000-5000. An alternative to TPLO surgery, in this surgery, a vertical cut in the front of the tibia (shinbone) is made and advanced forward. The cut piece of bone is held in place by metal plates and screws and helps to level the slope of the tibia, stabilizing the knee in the absence of the CCL.