We will discuss cruciate ligament grading and how it can help inform the best treatment approach for your patient, whether conservative or surgical. This article will also cover rehabilitation modalities, nutraceuticals, pharmaceuticals and physical rehabilitation exercises.
WHAT IS CRUCIATE DISEASE?
Cruciate disease is the most common cause of pelvic limb lameness, costing more than $1.3 billion in 20031. The cranial cruciate ligament resists motion in all planes of movement of the stifle. It may rupture because of biomechanical stresses (trauma, degeneration, or conformation abnormalities), signalment factors or immune-mediated destruction of the ligament.
A torn ligament can cause joint instability, decreased weight bearing, increased stifle flexion, osteoarthritis, joint effusion, muscle weakness and compensatory problems, including contralateral cruciate ligament rupture, increased thoracolumbar flexion and increased weight bearing in the thoracic limbs.
Soft tissue strains are classified according to the severity of the strain. A grade 1 strain involves less than 5% fiber disruption with synovitis. A grade 2 strain is a partial tear associated with pain and some instability, while a grade 3 strain is a complete tear with instability. Grade 2 tears continuously stress the damaged ligament, perpetuating inflammation within the stifle. The highest rate of complications and treatment failures occurs in grade 2 cases.
During the examination, it is important to determine the extent of the cruciate injury. Grade 1 tears produce pain during cranial drawer and tibial thrust testing but do not result in instability, or movement during testing. Mild to moderate instability with cranial drawer and tibial thrust and pain typically indicate a grade 2 tear. Great instability in cranial drawer and tibial thrust with minimal discomfort suggest a grade 3 tear.
WHY IS CRUCIATE DISEASE THE LEADING CAUSE OF LAMENESS?
There is growing concern that CCLR disease is becoming more common as more dogs live primarily indoors, have higher body condition scores and lack appropriate conditioning for physical activity. So-called weekend warriors, squirrel chasers and occasional Frisbee enthusiasts may become lame if they have not adequately conditioned and strengthened the relevant muscle groups. Obesity may also contribute to cruciate disease by increasing the forces placed on the stifle and promoting systemic inflammation.
WHO IS THE RIGHT CANDIDATE FOR CONSERVATIVE MANAGEMENT?
The ideal candidate for conservative management weighs less than 30 pounds, lives a relatively inactive lifestyle, has a healthy body condition, a dedicated owner, no meniscal injury and either a grade 1 or grade 3 cruciate tear. Grade 2 tears lead to delayed healing, persistent pain and long-term consequences, such as osteoarthritis, are likely to occur.
WHAT ARE WE TRYING TO ACCOMPLISH?
The goals of conservative management include reducing pain and inflammation, allowing time for the body to stabilize the joint through periarticular fibrosis, building muscle to support the joint and addressing compensatory issues.
PRINCIPALS BEHIND CONSERVATIVE MANAGEMENT
The body will attempt to stabilize an unstable joint by forming periarticular fibrosis, osteophytes, chondrocytes and other changes associated with early osteoarthritis. Typically, sufficient periarticular fibrosis develops within six months to help stabilize the joint.
Patients that receive no intervention often stabilize during this period but may develop extensive arthritis, reduced range of motion and significant muscle atrophy. The goal of conservative management is to lessen the natural consequences of leaving an unstable joint untreated. This includes minimizing fibrosis, maintaining range of motion, strengthening surrounding muscles and reducing compensatory stress on other limbs.
Osteoarthritis will develop, so initiating joint supplements at this stage to help limit cartilage damage is important.
ORTHOTICS
Many orthotic companies provide braces for stifle stabilization, but appropriate patient and client selection is essential for successful use. Bracing options range from light neoprene wraps to rigid, structured braces.
Prices vary, but a custom-fitted brace typically costs $800 to $1,200, requires two to four weeks for fabrication and may need to be returned to the orthotist for multiple revisions to achieve a proper fit. Establishing a relationship with a local orthotist can be helpful, as patients can be referred directly for fabrication and fitting.
Challenges with bracing often stem from anatomical differences between the canine stifle and the human knee. Additionally, a brace may give owners a false sense of security that the pet can run, jump and play on a diseased stifle. Orthotics may be incorporated into conservative management and combined with rehabilitation and regenerative medicine.
REGENERATIVE MEDICINE
Regenerative medicine, including mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP), may help reduce inflammation and promote healing of damaged tissue through the release of growth factors. PRP injections may be used in cases of cruciate injury managed conservatively, as well as perioperatively or postoperatively. Although PRP does not repair the ligament, it may reduce inflammatory mediators and help create a more favorable healing environment within the joint.
SUMMARY
Conservative management of cruciate ruptures can be successful when the appropriate patient is selected. Surgery remains the gold standard, but for patients who are not surgical candidates, conservative treatment may help them live comfortable, pain-free lives.
These patients are typically monitored by a rehabilitation therapist at least annually to assess osteoarthritis and compensatory issues that may develop.
References:
- Wilke et. al. “Estimate of the annual economic impact of treatment of cranial cruciate ligament injury. JAVMA. Vol 227, No.10, Nov 2005.
- Piemattei, Flo, DeCamp. Handbook of Small animal Orthopedics and Fracture Repair. 4th edition. Saunders 2006.
About the Author
Lisa Mason | DVM, CCRT, CVA, CVPP
Dr. Lisa Mason is the founder and managing veterinarian at Florida Veterinary Rehabilitation in Deland, FL. Her passion for veterinary rehabilitation grew out of her desire to help senior pets move easier with less pain to allow owners more time with their aging pets. She grew up in the suburbs of Atlanta, Ga and went to Emory University for her undergraduate degree. She graduated from Auburn University College of Veterinary Medicine in 2012. She went on to attend the Canine Rehabilitation Institute and Chi Institute with certificates as a Canine Rehabilitation Therapist and Veterinary Acupuncturist, respectively. She moved to Florida in 2013 to begin working at Florida Wild Veterinary Hospital in Deland, Fl as an integrative, rehabilitation, and exotics veterinarian.
In July 2018, she opened Florida Veterinary Rehabilitation, a standalone veterinary rehabilitation facility. She treats a variety of conditions including: pain, osteoarthritis, soft tissue sprains and strains, postsurgical rehabilitation, conservative management of injuries, neurological disorders, and sports evaluations.
In 2020, she completed the course work to become a Certified Veterinary Pain Practitioner to better understand and apply a multimodal approach to pain management in her patients. In 2022, Florida Veterinary Rehabilitation expanded into a new facility and added new associate rehabilitation veterinarians and certified support staff to continue paving the way in state-of-the-art rehabilitation medicine. Dr. Mason performs advanced non-surgical procedures to aid in the treatment of osteoarthritis, tendinopathies, and ligament damage. She has used platelet rich plasma and rehabilitation modalities to return high level athletes back to work after injuries. Dr. Mason enjoys spending time with her family and pack of animals, as well as cycling, working out, and spending time on the beach.