Monday, March 27, 2017

How CCL Injuries Affect Dogs

Damage to the cranial cruciate ligament (CCL) is the most common cause of canine hind limb lameness and is a major cause of degenerative joint disease in the stifle (knee) joint of companion dogs. The cranial cruciate ligament is critical to stabilizing a dog’s stifle, which is the equivalent of the human knee. When the CCL is torn, the upper ends of the two long lower leg bones (the tibia and fibula, like the shin bone in people) become loose within the knee joint, causing abnormal friction, wear and tear. This, in turn, leads to joint swelling (effusion), stifle joint instability, pain, lameness in the affected rear legs and, ultimately, chronic irreversible degenerative joint changes. Dogs with ruptured CCLs will become lame suddenly, because of the pain associated with this injury. They may feel better after rest, but once they rise, walk around or exercise, the pain will return, as will the lameness. They will just plainly hurt.

Symptoms of CCL Injury

The outward signs of cruciate damage depend upon the severity of the injury, which can range from a partial tear to a complete rupture of the affected ligament. Without surgical correction and appropriate post-operative management, the effects of CCL injuries can progress and become permanent. Most owners of dogs with cranial cruciate ligament injuries first notice a sudden onset of lameness or limping in one or both rear legs. Most of these injuries happen when a dog is romping, roughhousing, running, playing, jumping or engaging in other enthusiastic antics. Owners often report that their dog suddenly stumbled, possibly yelped and then “came up lame.” However, the affected ligament probably experienced excessive wear and tear well before observable signs of damage became apparent.

Symptoms of this condition that owners may notice include:
- Lameness in one or both hind legs; may be non-weight-bearing; may come and go; may come on very suddenly
- Limping or reluctance to use one or both hind limbs, which worsens with exercise and improves with rest
- Weakness
- Abnormal posture, especially over the back and hip areas
- Reluctance to rise, run or jump
- Morning stiffness that takes time to “warm out of”
- Sitting at an odd angle, with a hind leg slanted off to one side
- Swelling (effusion) around the stifle joint
- Atrophy (withering away) of the muscles of the affected limb

All or only some of these signs may be noticed by owners. However, regardless of the severity of the injury, the signs of CCL damage usually become worse if they are not treated, because the pain felt by the dog increases as the stifle joint progressively deteriorates.
Dogs At Increased Risk

All breeds and both genders are susceptible to this injury. Rottweilers, Labrador Retrievers, Staffordshire Bull Terriers, Newfoundlands and other active, large-breed dogs seem to be at an increased risk of suffering from CCL damage. Most affected animals are in good body condition and are not systemically ill at the time of their injury. Rupture of the CCL can happen in any dog at any age, but it is more likely to occur in young, active animals. When a cruciate ligament ruptures in one leg, there is an increased chance that the CCL in the other leg will eventually become compromised, probably because of the increased weight that will be required to support the other leg as it heals.

Goals of Treating Canine CCL Injuries

When a dog suddenly comes up lame in one or both hind legs, its owner should take it to a veterinarian as soon as possible. Left untreated, damage to the stifle (knee) joint usually is progressively degenerative; any chance of reasonable recovery wanes without treatment. A dog that favors an injured leg for a long period of time also runs a significant risk of eventually damaging some part of its “good” leg, because it is being over-used. The goals of treating canine cruciate ligament (CCL) injuries are to relieve pain, improve stability and function of the stifle joint and minimize the progression of degenerative changes.
Treatment Options

Dogs that injure their cranial cruciate ligament suddenly (acutely) should start medical management as soon as the injury is diagnosed. “Medical management” means treatment with medication and other sorts of supportive care. Conservative medical management of CCL injuries includes administration of non-steroidal anti-inflammatory drugs (NSAIDs), subcutaneous or intravenous fluids, rest, exercise restriction and possibly corticosteroid therapy. Steroids should not be given at the same time as NSAIDs, because severe gastrointestinal and other adverse side effects can occur when these two types of drugs are combined. Sometimes, medical management without surgery is all that is needed for small dogs, older dogs or dogs whose CCL is only stretched or partially torn. However, in most cases, surgical stabilization of the stifle joint is the only effective way to treat this injury and reduce the risk of future degenerative damage to the joint. Torn or ruptured cruciate ligaments will not re-attach or re-grow without surgical intervention.

There are a number of surgical options for stabilizing the stifle joint, and more are being developed all the time. Some of the current techniques include intra-articular grafts, extra-capsular suture stabilization, tibial plateau leveling osteotomy (TPLO), tibial tubercle advancement (TTA), arthroscopic reconstruction and medial meniscal release. A detailed description of these surgical techniques is beyond the scope of this article. A dog’s veterinarian is the best one to assess its injuries and select the best surgical procedure in any given case. Frequently, a general practitioner will consult with or refer the dog to a veterinary orthopedic specialist, because selection of the “best” surgical technique remains controversial even among experts.

After surgery, the dog normally will be managed medically with non-steroidal anti-inflammatory drugs, and possibly other drugs or supplements to promote healthy cartilage repair (these are called “chondroprotective agents”). A number of chondroprotective supplements are available, both over-the-counter and by veterinary prescription, to help keep cartilage and joints well-lubricated. These include polysulfated glycosaminoglycans, glucosamine, chondroitin sulfate, hyaluronan, Vitamin C, omega 3 and 6 fatty acids and MSM, among others. These can be quite effective in reducing inflammation and relieving pain.

In many cases, good dietary management and weight loss alone can dramatically reduce the pain and other symptoms that accompany CCL damage, as overweight dogs tend to suffer more from this injury than do fit dogs. Moderate, regulated exercise and/or exercise restriction can stimulate cartilage growth and help delay joint degeneration, and long controlled walks in early or mild cases of CCL damage may help prevent loss of rear muscle mass. Physical therapy, hydrotherapy (swimming and other water exercises), passive flexion and extension of the affected limb and controlled low-impact on-leash walks often are incorporated into the recovery process. It takes a long time – often months – for a dog to heal from CCL surgery. During much of that time, the dog should be strictly confined and only walked outside on a leash to potty.

Other, less traditional techniques that may or may not benefit affected dogs, in addition to medical treatment, might include: massage therapy to stimulate blood flow to the stifle area and reduce joint stress; application of acupuncture and/or acupressure techniques; use of herbal or other non-regulated supplements or homeopathic “remedies”; and other forms of supportive care that may help to ease pain, increase circulation, speed healing and otherwise promote wellness, relaxation and comfort. Some of these adjunct approaches lack controlled studies of their effectiveness and may not have established quality control methods or ways to assess their benefit to dogs with partially or totally torn or ruptured cranial cruciate ligaments. Chiropractic adjustment or manipulation of dogs with musculoskeletal conditions is highly controversial among veterinary professionals, unless it is performed by or under the direct supervision of a veterinarian with orthopedic expertise.

Dogs that undergo surgical correction of injured cruciate ligaments have a very good prognosis for return to long-term, pain-free function. Stabilization of the stifle joint, post-operative treatment with non-steroidal anti-inflammatory medications, and judicious rehabilitation typically result in rapid resolution of the pain that caused the lameness. If joint effusion (swelling) and discomfort persist, some dogs respond well to steroid therapy at immunosuppressive levels (but not at the same time as NSAIDs are being administered). Owners should know that following damage to the CCL in one leg, the other leg is at a greatly increased risk of suffering a similar injury – even if the first injury is surgically corrected. The contralateral (or “good”) limb is forced to bear an unusually large amount of additional weight, stress, wear and tear before surgery on the “bad” limb takes place, and also during the long recovery process, which typically takes months.


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