Anterior Cruciate Ligament (ACL) is a common injury in humans, and in dogs. In dogs the same ligament is called the Cranial Cruciate Ligament (CCL). In humans, this disease is a traumatic disease (as seen in soccer and basketball players for example). In dogs, there is a degenerative process that occurs in the knee, which predisposes dogs to tearing their CCL. Dogs can tear their cruciate doing any activity, even if it is not very athletic. CCL disease is multifactorial; it can happen in active dogs, be hereditary, occur as a result of trauma, and can be related to an individual dog’s anatomy.

Clinical Signs – You may notice your dog becomes acutely lame on a rear limb, possibly after a slip, fall, or athletic activity. If it is a partial CCL tear, your pet may put some weight on the leg. Dogs can also tear their meniscus (the shock absorber in the knee), which can be very painful.

Diagnosis – CCL tears can be diagnosed on a physical exam. Sometimes sedation or pain medication may be required to complete the exam due to the discomfort associated with the tear.

Radiographs – X-rays of the knee are important to ensure there are no other bony abnormalities present. Many times arthritis is associated with chronic cruciate disease and may be visible on radiographs. If trauma caused CCL rupture, it is good to know fractures or other bone injuries are not present. Radiographs can be performed at the time of diagnosis, or the day of surgery.

Treatment – There are many ways to fix CCL tears, and a TPLO surgery is one of the most common.

TPLO – or Tibial Plateau Leveling Osteotomy – is a bone cutting procedure that permanently fixes the torn cranial cruciate ligament. A TPLO procedure changes the anatomy and biomechanics of the knee, and eliminates the need for the cruciate ligament altogether. After the bone is cut and rotated a specific number of degrees based on preoperative radiographs, a stainless steel plate is applied to the inside part of the knee to allow the bone cut to heal. Once the bone cut is healed, the implanted plate is no longer needed, however the plate is typically left in for life, unless there are complications. Perhaps the most important part of the TPLO procedure is the strict activity restrictions in the 8 week post-operative period. This restriction from activity is needed to allow the bone to heal, and includes a gradual increase in controlled activity. Once the bone is healed, your pet can run, jump, play, and do everything that he or she, and you, want them to do!

Dr. Dusty Spencer, our staff surgeon, has been performing TPLO surgeries for years, and has even published a research study on TPLO procedures ( Under anesthesia immediately before the TPLO procedure, Dr. Spencer recommends arthroscopy, where a camera is placed into the knee to visualize the CCL tear, and evaluate the meniscus for damage. Dr. Spencer is then able to remove the torn CCL remnants, clean up the knee, and take care of the meniscus – all under minimally invasive arthroscopy, using the camera.

Rehabilitation – Physical rehabilitation is also a very important part of the recovery process after TPLO surgery. AIPS’ Rehabilitation team is lead by a Physical Therapist (holding a Master’s degree in Physical Therapy) to help guide you through the recovery process to maximize your pet’s outcome postoperatively.