🧠 Understanding the Canine Knee

The canine knee, or stifle joint, is a complex structure composed of the femur (thigh bone), tibia (shin bone), patella (kneecap), and the menisci (cartilage pads). It’s held together by several ligaments, including the cranial cruciate ligament (CCL), which prevents the tibia from sliding forward under the femur. When this ligament ruptures, the joint becomes unstable and painful. 🦴

🔍 Recognizing a CCL Rupture

Most ruptures occur suddenly and cause immediate lameness. Common signs include:

• 🐾 Sudden non-weight-bearing lameness in a hind leg
• 🦿 Swelling on the inside of the knee (medial buttress)
• 🧪 Positive “drawer sign” or “tibial thrust” on exam

Diagnosis may require sedation for proper manipulation and radiographs to assess joint damage and rule out fractures.

📉 Causes of CCL Injury

There are two main presentations:

• 🎾 Young, active dogs with a sudden injury during play
• ⚖️ Older or overweight dogs with gradual ligament weakening that culminates in a rupture during normal movement

Breeds at higher risk include: Labrador Retrievers, Rottweilers, Golden Retrievers, Akitas, St. Bernards, Newfoundlands, and more.

🔄 What Happens Without Surgery

Without surgical repair, the knee remains unstable. This leads to:

• 🦴 Rapid development of osteoarthritis
• 😖 Persistent lameness and pain
• 🦵 Degeneration of cartilage and meniscal damage

Smaller dogs (<30 lbs) may compensate better, but most dogs—especially larger breeds—need surgical stabilization.

🩺 Surgical Repair Options

1. Extracapsular Repair

• ✅ Best for small dogs under 45 lbs
• 🧵 Uses a strong suture to mimic the ligament
• ⏳ 8–12 weeks recovery with exercise restriction

2. TPLO (Tibial Plateau Leveling Osteotomy)

• 🔩 Involves cutting and rotating the tibia
• 💪 Designed for large or athletic dogs
• 💰 More invasive and expensive
• ⏱️ 3–4 month return to full activity

3. TTA (Tibial Tuberosity Advancement)

• 📐 Alters patellar ligament angle with implants
• 🏋️ Similar recovery and results to TPLO

⚠️ No single method is superior in all cases—discuss your dog’s specific needs with your vet.

🔧 Post-Operative Rehabilitation

All surgical repairs require careful post-op management. Key elements include:

• 🧊 Ice therapy in the first 1–2 weeks
• 🚶‍♂️ Controlled leash walks
• 🧘 Passive range of motion exercises
• 💧 Hydrotherapy or underwater treadmill (from 2–4 weeks post-op)
• ⛓️ Strict confinement to prevent reinjury

🧬 Meniscal Damage

The medial meniscus is often damaged during CCL rupture. This may cause a clicking sound in the joint. During surgery, your vet will assess and either:

• 🩹 Remove the torn section
• 🧵 Attempt repair (less common due to poor healing)

📋 Quick Comparison of Procedures

🧴 Enhancing Recovery

• 💉 Adequan injections: Improve joint lubrication
• 🦴 Joint supplements: Glucosamine, chondroitin, omega-3s
• ⚖️ Weight loss: Reduces stress on joints
• 💆 Professional rehab: Physical therapy, treadmill, cold laser

🔄 Secondary Rupture Risk

Sadly, dogs that rupture one CCL are at high risk of rupturing the other within 6–12 months. Preventive care includes:

• ⚖️ Keeping your dog lean
• 💪 Maintaining muscle strength through rehab
• 🔎 Monitoring for early signs of lameness

🔧 Ask A Vet Can Help

Need help deciding on a surgery or navigating post-op recovery? Use the Ask A Vet app to consult with orthopedic vets, track healing progress, and receive custom rehab plans. 🐾💬

🐾 Final Thoughts from Dr Duncan Houston

Ruptured cranial cruciate ligaments are painful and debilitating—but with proper surgical treatment and structured rehab, most dogs return to happy, active lives. Work closely with your vet, follow rehab steps carefully, and your dog will be back on their paws soon. ❤️