Cruciate Ligament Disease
Cranial cruciate ligament (CCL) disease is the most common orthopedic condition in dogs and the leading cause of hind limb lameness. Unlike acute ACL tears in humans, canine CCL disease is typically a progressive degenerative process where the ligament weakens over time before partial or complete rupture. It leads to joint instability, meniscal damage, and osteoarthritis.
Symptoms & Signs
- Sudden or progressive hind limb lameness
- Sitting with leg extended to the side
- Stiffness after rest
- Difficulty rising
- Muscle atrophy of affected leg
- Joint swelling (effusion)
- Clicking sound (meniscal tear)
Causes & Risk Factors
Primarily degenerative: chronic inflammation and weakening of the ligament fibers over time. Contributing factors include obesity, conformational abnormalities (steep tibial plateau angle), genetic predisposition, immune-mediated inflammation, and hormonal influences (early neutering may increase risk).
Diagnosis
Physical examination: cranial drawer sign and tibial thrust test. Radiographs showing joint effusion, osteophytes, and tibial displacement. Arthroscopy for definitive assessment of ligament and meniscal status. 40-60% of dogs rupture the contralateral CCL within 1-2 years.
Treatment
Surgical stabilization preferred: TPLO (tibial plateau leveling osteotomy), TTA (tibial tuberosity advancement), or lateral suture technique. Choice depends on dog size and surgeon preference. Post-operative rehabilitation essential. Conservative management for small dogs (<15kg) or poor surgical candidates.
Prevention
Maintaining healthy body weight. Appropriate exercise (avoiding repetitive high-impact activities). Delaying neutering in large breeds may reduce risk. Strengthening hind limb musculature.
Prognosis
Surgical: 85-90% return to good-excellent function. TPLO has best evidence for large dogs. Without surgery: chronic lameness and progressive osteoarthritis. Meniscal damage worsens prognosis. Contralateral rupture risk is significant.