Anterior Cruciate Ligament (ACL) Repair

What is ACL/CCL ?

The cranial cruciate ligament or anterior cruciate ligament   (C) is one of the main stabilizing structures of the stifle joint (in man this joint would be called the knee). The cranial cruciate ligament serves to prevent forward movement/Slipping of the tibia bone (shin bone) relative to the femur bone (thigh bone), to prevent internal rotation of the tibia bone, and to limit hyperextension of the stifle. Its main job is to hold the femur and tibia in proper alignment during all forms of activity.

Two meniscal cartilages (M) located inside of the joint are crescent-shaped pads that serve as cushions, provide stability to the joint, and help to push the nourishing joint fluid into the cartilage of the femur and tibia bones. Several other ligaments also hold the stifle together, however, infrequently rupture in dogs

Cranial Cruciate ligament disease

  • Cranial cruciate ligament disease is the most common orthopedic condition in dogs and inevitably results in degenerative joint disease (arthritis) in the knee joint. It is referred to as a disease because it is typically the result of a degenerative process in the knee joint of dogs, rather than from athletic injury or trauma. Traumatic CCL rupture may be seen in less than5-10% of the total CCL ruptures seen in dogs.
  • It may affect all breeds of the dogs but most common in Labrador retrievers, Rottweilers and Mastiffs of any age.
  • The ligament may undergo progressive degeneration and partial tearing over a period of months before it suddenly ruptures during normal physical activity and shows the symptoms of CCL rupture.
  • The cause is unknown, but conformation of the limbs and genetics may play a role.
  • Partial ligament tears may be difficult to diagnose and frequently occur in both legs at the same time.
  • When the ligament tears, the stifle becomes unstable. The femur and tibia bones that form the joint then rub back and forth on each other (termed “drawer movement”). This results in pain due to stretching of the joint capsule, potential damage to the meniscal cartilage, and inflammation of the joint (called arthritis). In about half of the patients that we operate, the meniscal cartilage on the inner side of the joint (medial meniscus) has been torn and the damaged portion must be removed.

Symptoms of CCL disease

Some of the symptoms your pet may display are:

  • Limping
  • Holding the hindlimb up
  • Sitting with the leg stuck out to the side
  • Stiffness, especially after excercise
  • Not wanting to play or excercise
  • Pain when the joint is moved or touched
  • Swelling of the joint
  • Clicking sound when walking

How is ACL disease diagnosed

Your veterinarian should review your dog’s medical historyand perform a complete examination using tests of the integrity of the CCL, including the “cranial drawer” and”tibial thrust” tests. X-rays should be performed to assess the amount of arthritis present and aid in determining treatment options. Sedation or anesthesia is necessary for making the definitive diagnosis, to avoid causing pain to your pet.

Surgical Treatment Options Available at Allwest Animal Hospital:

  • Extra-capsular: ECR/ Lateral suture or TightRope Techniques
  • Intra-capsular or anatomical correction: With TPLO
  • Neuteralizing the shearing forces with TTA


Lateral Suture Stabilization (LSS)

  • This technique is used most commonly for small dogs and cats.
  • It is one of the extracapsular techniques which means the function of the ccl ,which is inside the joint, is replaced by placing a suture outside the joint.
  • The suture , most commonly a type of medical grade “fishing line”, is placed around the fabella and through the proximal tibia.


TightRope Technique (TR)

  • This is used for all medium breed dogs, Sometimes in large breed dogs where tibial plateau angle is less than 25 degrees and there is no meniscus tear or no DJD (arthritis) yet present in the joint.
  • This is an improved method for extracapsular stabilization of the ccl.
  • This technique uses small drill holes in the femur and tibia to pass a synthetic ligament-like biomaterial
  • through a small incision to provide bone-to-bone stabilization. The biomaterial is called FiberTape and
  • has the properties that make it stronger and less prone to failure than any other suture materials currently being used for CCL reconstruction.
  • Large or Giant breeds of dogs have a better outcome when the TPLO is performed.
  • We have noted that dogs that have a steeply-sloped tibial plateau should receive the TPLO instead of the lateral imbrication technique or TightRope regardless of their size. The lateral imbrication technique cannot overcome the forces on the stifle joint caused by a steep slope and frequently the nylon band will tear or loosen in the postop period.
  • All dogs that are going to have cruciate surgery should
  • have a correctly positioned x-ray taken to measure the
  • slope of the tibia so that an informed decision can be
  • made on the appropriate type of surgery that should be performed. In our experience dogs that have a steep tibial slope (especially large breeds) do much better with the TPLO surgery. This may not be an important factor in small breeds even with a steep tibial slope, but the clients should be aware of the fact that a steep tibial slope will put much greater force on the nylon bands, therefore they may break.

Expected convalescent period

  • By 2 weeks after the surgery, your pet should be touching the toes to the ground at a walk.
  • By 8 weeks the lameness should be mild to moderate.
  • By 6 months after the surgery, your pet should be using the limb well.

Success rates

  • With the extracapsular techniques, about 85% of the cases are significantly improved from their preoperative state. With the extracapsular technique, we can expect that 50% of these dogs will have some degree of lameness, whether it is mild or intermittent following heavy activity.  On the other hand, about 50% regain normal function of the limb.
  • Even though these surgeries  may not return the limb to perfectly normal function, these dogs usually are greatly improved over their condition prior to surgery.
  • The extracapsular techniques will not stop the progression of arthritis that is already present in the joint. As a result, your pet may have some stiffness of the limb in the mornings. In addition, your pet may have some lameness after heavy exercise or during weather changes.  To help with stiffness chondroitin sulfate, MSM and glucosamine combinations may be given.

Potential complications

  • Anesthetic death can occur, but is rare
  • Infection at the surgical site
  • Sterile reaction to the nylon bands/FiberTape
  • Premature loosening or breakage of the nylon bands in LSS
  • If the meniscal cartilages were not found to be damaged at the initial surgery, it is possible that damage may occur at a later date, thus requiring a second surgery. The sign of a meniscal tear is a sudden onset of lameness.
  • Entrapment of the peroneal nerve by the nylon sutures(LSS) is very painful and can result in permanent functional impairment of limb function.

Postop care

  • Ice pack the stifle three times daily, 10 minutes per session for the first 2 days to help reduce the swelling and pain.
  • Hotpack the stifle starting on the third day after surgery, 10 minutes per session prior to the passive range of motion of the joint.  The hotpacking will soften the soft tissues prior to the range of motion of the joint and will make it less painful to do the exercise.
  • Passive range of motion of the joint involves flexing and extending the stifle joint, and should be done 10 minutes following the hotpacking. After the range of motion exercises have been completed, a cold compress is applied to the stifle for about 5 to 10 mintues.
  • The rehabilitation therapy should be done until your pet is bearing a significant amount of weight on the limb.
  • During the first two months, activity is restricted to short leash walks outside.
  • Running, jumping, and rough play are forbidden.
  • Gradual increasing the activity during the third month after surgery allows for a safe return to function.
  • Unleashed activity can take place after four months.

For further information or to schedule an appointment, please contact Allwest Animal Hospital at 604-870-9333 or request an appointment online.