A dog's cranial cruciate ligament (CCL) is also called an ACL or 'cruciate'. This tissue connects the shin bone to the thigh bone and when it gets torn or injured it can be very painful. In this blog, our Hoquiam vets discuss the causes of ACL injuries in dogs as well as two different types of ACL treatment surgery available.
What is the Cruciate, CCL, or ACL?
We have a thin piece of connective tissue in our knee called the anterior cruciate ligament (ACL) that connects the lower leg bone (tibia) to the upper leg bone (femur) it allows our knee to function efficiently. Your dog also has similar connective tissue that joins their tibia to their femur but, this tissue in dogs is called the cranial cruciate ligament or CCL.
Even though a dog's CCL and a person's ACL work a little differently, pet parents and veterinarians generally interchangeably refer to the dog's cranial cruciate ligament as their ACL, CCL, or 'cruciate'.
How could my dog tear or injure their ACL?
ACL injuries in dogs don't often come on suddenly they usually appear gradually over time, and increasingly become worse with activity. For lots of dogs, there is no single moment when they all of a sudden injure their ACL, instead, the injury usually comes on as a result of continuous exercise. Their symptoms will appear mild at first and gradually became more severe and painful for your dog.
What are the symptoms of an ACL injury in dogs?
A dog that is suffering from a torn ACL will not be able to walk normally and will experience significant pain. If your dog has torn their ACL you may notice that they are limping in their hind legs, showing signs of stiffness following exercise, and having difficulties jumping or rising up off of the floor.
What happens will happen if my dog injures or tears their ACL?
When a dog's ACL has been injured, the tibia slides forward in relation to the femur. This forward sliding movement is known as a 'positive drawer sign' and results in knee instability which can lead to osteoarthritis or damage to the cartilage and surrounding bones.
What are the treatment options for a torn ACL in dogs?
If you notice signs of an ACL injury in your dog you need to have their condition diagnosed by a vet as quickly as possible, so they can start treatment before the condition becomes worse. Many dogs with just one ACL injury will often go on to injure their other legs not long after.
Surgery Options for Treating ACL Injuries in Dogs
Extracapsular Lateral Suture Stabilization - ELSS / ECLS
This surgical treatment works by counteracting the sliding forward of the dog's shinbone ('tibial thrust') with a specifically placed suture.
The sliding motion of tibial thrust is caused by the transmission of weight up the dog's tibia and across the knee, causing the tibia to “thrust” forward in relation to the dog's femur (thigh bone). This forward thrust movement occurs because the top of the tibia is sloped, and the dog's injured ACL which would normally be able to oppose the forward force, is no longer able to prevent the unwanted movement from occurring.
Extracapsular Lateral Suture Stabilization corrects tibia thrust by “anchoring” the tibia to the femur with a suture placed by your dog's surgeon. The suture stabilizes the dog's knee by pulling the joint tight and preventing the front-to-back sliding of the tibia so that the ACL has an opportunity to heal itself, and the muscles surrounding the knee have a chance to regain their strength.
ELSS surgery is fairly quick and uncomplicated with a good success rate in small to medium-sized dogs. ELSS surgery can also be less expensive than other ACL surgical treatment options. The long-term success of ELSS surgery varies in dogs of different sizes and activity levels. Speak to your vet to find out if ELSS surgery is an option for your injured dog.
Tibial Plateau Leveling Osteotomy - TPLO
The next surgical option we'll look at for treating your dog's injured ACL is the tibial plateau leveling osteotomy (TPLO). This surgery is more complicated than ELSS surgery and aims to reduce tibial thrust without relying on the dog's ACL (CCL).
This surgery involves making a complete cut through the top of the tibia (the tibial plateau), then rotating the tibial plateau in order to change its angle. Finally, a metal plate is added to stabilize the cut bone as it heals. Over the course of several months, your dog's leg will gradually heal and strengthen.
Full recovery from TPLO surgery in dogs takes several months however some improvement can be seen within just days of the procedure. Following your vet's post-surgery instructions and restricting your dog's activities, are essential for successful healing. TPLO surgery in dogs has a good long-term prognosis, and re-injury is uncommon.
What is the recovery tie for dogs after ACL surgery?
Some dogs recover faster than others after their ACL surgery but, the recovery time for a torn ACL is always a long process!
Many dogs will be able to walk as early as 24 hours after the surgery, but it can often take 12 - 16 weeks for a full recovery and for them to return to normal activities, possibly longer.
It's important to follow your vet's instructions carefully, pay close attention to your pup's healing progress, and not rush exercise following ACL surgery. Never force your dog to do exercises if they resist as this can make them re-injure their leg.