Cranial Cruciate Ligament Rupture in Dogs
One of the most common causes of hind-limb lameness in dogs, involving a torn knee ligament that often develops gradually rather than from a single injury.
Overview
Cranial cruciate ligament (CCL) rupture involves partial or complete tearing of the ligament stabilizing the knee (stifle). While it can occur acutely from trauma, it more often develops from gradual ligament degeneration over time, and predisposes the joint to secondary meniscal injury and osteoarthritis.
Clinical signs
- Hind-limb lameness, ranging from intermittent and mild to complete non-weight-bearing
- Sitting with the affected leg held out to the side
- Joint swelling or effusion
- An audible or palpable "click" if the meniscus is also torn
Diagnosis
- Orthopedic exam findings, including the cranial drawer test and tibial thrust test
- Radiographs to assess joint effusion and evaluate for pre-existing osteoarthritis
- Advanced imaging in select cases
Treatment
- Surgical stabilization for most dogs, especially larger or more active ones - common techniques include TPLO, TTA, or extracapsular repair
- Conservative management (rest, weight control, physical rehabilitation) considered for smaller dogs or poor surgical candidates
Prognosis
Generally good to excellent with appropriate surgical repair and rehabilitation. Dogs that rupture one CCL are at increased risk of rupturing the opposite knee over time.
This page is general reference information for educational purposes. It is not a substitute for an individual clinical assessment, current formulary guidance, or the judgment of a licensed veterinarian treating a specific patient.
Frequently asked questions
Does my dog definitely need surgery for a torn cruciate ligament?
Surgery generally gives the best long-term outcome, especially for larger or more active dogs. Conservative management can be considered for smaller dogs or those who aren't good surgical candidates, but your vet can help weigh the options for your specific dog.
Will my dog tear the other knee too?
It's a recognized risk - a meaningful proportion of dogs that rupture one cranial cruciate ligament go on to injure the opposite knee within a couple of years, so keep an eye on that leg going forward.