What Is a Cranial Cruciate Ligament (CCL) Tear?
The stifle joint (or knee) in dogs is the joint between the femur and tibia bones. Inside this joint are several important structures, the medial and lateral menisci (cushion between bones) and the cranial and caudal cruciate ligaments.
One of the most common orthopedic injuries in dogs is damage or a tear of the cranial cruciate ligament (CCL). This ligament attaches from the back of the femur down to the front of the tibia.
This injury can range from a partial tear to a complete tear. There is a natural backwards slope to the weight-bearing surface of the tibia. This is referred to as the Tibial Plateau Angle (TPA). If the cruciate is intact, the joint is very stable.
When a dog bears weight with a damaged CCL, the femur will slide down the back of the tibia, forcing the tibia forward. This abnormal movement is called tibial thrust. The tibial thrust is painful, puts the meniscus at risk for damage, and begins to wear down the smooth cartilage, creating arthritis.
Surgical Options for CCL Tears
In humans, the ACL can often be repaired, but in dogs that is not an option. The ligament is often in pieces or frayed like a rope.
The canine knee with CCL disease will naturally try to help stabilize the joint by thickening the joint capsule. This can create some degree of stability during low-intensity movements, but does not solve the problem.
The original surgery back in the 70’s aimed at stabilizing the joint with a thick suture on the outside of the joint that runs in the same direction as the CCL. This prevents the tibial thrust, but over time the suture will stretch or break. This procedure is still done, but generally is done on smaller dogs.
In the late 90’s, the idea of changing the geometry of the joint became the new focus for surgical correction. These two procedures are the TPLO (Tibial Plateau Leveling Osteotomy) and the TTA (Tibial Tuberosity Advancement). Both procedures have a similar success rate, but the TPLO is the most commonly performed surgery.
What Is TPLO Surgery?
TPLO stands for Tibial Plateau Leveling Osteotomy. The goal of the procedure is to change the tibial plateau angle to prevent the femur from sliding off the back of the tibia.
This is done by using a crescentic saw blade (1/4 of a circle) to cut the top of the tibia in half. The top of the tibia can then be rotated to a calculated distance to create the desired post-op plateau angle. The segment is then fixed in place with a large bone plate and screws.
The femur now sits on a relatively flat plateau and thus does not create excessive tibial thrust. This change in geometry negates the need for an intact CCL.
During this procedure, the joint is opened and explored to evaluate any damage to the meniscus. If there is a tear in the meniscus, it may be addressed by trimming the torn piece off or removing the entire damaged section.
It is always best to try and leave a normal meniscus in place because it does provide a cushion between the bones. If it is left intact, there is always a chance it could be damaged in the future, but much less likely.
Common Complications After TPLO Surgery
TPLO has a high success rate, but complications may occur if recovery protocols aren’t followed closely.
Swelling:
It is common to see some swelling around the incision and even down lower on the leg. This is normal for several days post-op.
Infection:
Most commonly due to licking of the incision.
- Ensure the pet is always wearing a hard plastic cone that extends beyond the tip of the nose for 2 weeks postoperatively.
- If the pet licks the incision, it can lead to an infection of the bone plate and/or screws. This becomes very problematic for healing.
Signs to Watch For:
- Redness, swelling, or discharge from the incision site
- Foul odor from the incision
- Fever or lethargy
- Open incision
Surgical Hardware Issues:
Signs to Watch For:
- Lameness or worsening pain despite rest
- Acutely painful or non-weight bearing
- Frequently happens after overactivity or a slip
- STRICT cage rest during the first 8 weeks of recovery is essential
Pivot Shift:
- Abnormal rotational instability after TPLO
- Creates a strange gait due to the rotation of the tibia inward when weight-bearing
- Rare and poorly understood
- Can occur intraoperatively or post-operatively and require a secondary procedure to stabilize
Delayed Healing or Non-Union:
Signs to Watch For:
- Persistent lameness or non-improvement in the leg after the initial recovery period
- No visible improvement in X-rays showing bone healing after 8 weeks
- Can be due to overactivity during recovery, infections, or implant loosening
Muscle Atrophy:
- Noticeable muscle loss in the affected leg is normal
- The goal is to build the muscle mass back up during the latter half of recovery
- Rehabilitation exercises or physical therapy may help to prevent or reduce muscle atrophy during recovery
- Gradually increasing activity after bone healing has been confirmed
TPLO Recovery Tips: Ensuring a Strong Outcome
Rest & Restricted Activity:
- Limit your dog’s physical activity, including jumping, running, and climbing stairs, for at least 8 weeks.
- Use a leash for bathroom breaks and only allow short, supervised walks as recommended by your vet.
- Use a towel to support their back end when walking on slick surfaces (particularly important in the first 2 weeks post-op).
Prevent Licking:
- Keep cone on at all times until the incision is healed
Pain Management:
- Administer pain medication on time and as directed
Follow-up Appointments:
- Schedule and attend all follow-up appointments with your veterinarian to monitor healing progress through physical exams and X-rays
- 2 weeks post-op: check incision, mobility, and remove staples
- 8 weeks post-op: check mobility and take X-rays to assess bone healing
Weight Management:
- Keeping your dog at a healthy weight is important to reduce stress on the healing leg
- Dogs tend to gain weight when their activity is restricted, so the food portions may need to be reduced during recovery
Is TPLO Right for Your Dog?
A cranial cruciate ligament tear can lead to long-term arthritis, pain, and mobility issues. If your dog is a good candidate for TPLO, it can restore function, relieve pain, and get them back to their favorite activities.
Call or book an appointment at All Pets Animal Hospital Rogers today to schedule your consultation and learn if TPLO is the best option for your dog. We’re here to help your best friend heal.