Dog ACL Surgery: FAQ with Our Vet Surgeon

This article was updated on March 10th, 2023

ACL injuries are a common orthopedic complaint in dogs, in fact so common that it accounts for up to 85% of orthopedic injuries in dogs! So, you may have heard of a dog suffering from an ACL tear, but what exactly is it?

The Anterior Cruciate Ligament, or ACL, is a small but vital ligament within a dog’s knee joint. If excessive pressure it put through the joint, the ACL can rupture resulting in instability, inflammation, and lameness. A ruptured ACL also allows the femur to slide unevenly on the tibia, resulting in damage to other important structures within the joint such as the menisci. The ACL can either partially rupture or completely rupture; your veterinarian may be able to ascertain the level of damage your dog has caused through a physical examination and X-rays.

Since so many owners experience an ACL rupture in their dog, it’s only natural for them to have a lot of questions, especially when a major, potentially expensive surgery is suggested as the solution. Here we will answer some of the most frequently asked questions by owners to try and shed some light on ACL surgery in dogs. 

About ACL surgeries for dogs

Quite a few different techniques have developed over the years for repairing a torn ACL. These all come with their own advantages and disadvantages – factors such as the weight of your dog, cost of the procedure and surgeon’s preference will determine the best type of surgery for your dog. 

The different ACL surgery techniques can be divided into two main categories: extracapsular and intracapsular, referring to whether the knee joint itself is opened up during the procedure. 

The main extracapsular technique is known as a lateral suture. This surgery aims to stabilise the knee joint by placing artificial sutures outside of the joint which aim to mimic the normal function of the ACL. While this procedure is the cheapest, usually costing between $900-2500, the main two disadvantages are that the artificial suture could rupture in a similar way that the original ligament did and that any other disease process such as a meniscal tear within the joint is not addressed. 

The two main types of intracapsular repair are called a Tibial Plateau Levelling Osteotomy (TPLO) and a Tibial Tuberosity Advancement (TTA). These are both complex procedures that involve entering the knee joint itself, sawing and moving bones followed by plating and screwing them into place. Both of these procedures have a similar success rate and a similar cost ($3500-$5000). The main determining factor as to which procedure your dog will have is surgeon preference/expertise. 

What happens if I do not do the surgery? Can dogs live with a torn or damaged ACL?

While some dogs with a partially ruptured cruciate ligament may respond to non-surgical treatment, these are the minority and so surgery is always recommended. A non-surgical approach includes hydrotherapy, physiotherapy, weight management and anti-inflammatory medication to relieve your dog of any discomfort and to try and strengthen the other structures surrounding the knee joint. However, this should only really be thought of as a short term solution as a partially damaged ligament is very liable to completely rupturing; surgery can prevent this from occurring before it’s too late. If your dog has been diagnosed with a fully torn cruciate ligament then surgery is the only option. 

When is ACL surgery warranted? 

ACL surgery is almost always warranted, especially if the cruciate ligament is fully ruptured or if there is evidence of other damage such as a meniscal tear within the knee joint. Only very small dogs may be able to cope without surgery but even then they are very prone to causing further damage. 

How much does surgery cost?

The cost of anterior cruciate ligament surgery will depend on many factors including the size of your dog, the level of damage within the knee joint, the surgical technique performed and the surgeon performing the procedure. X-rays and follow up appointments are also essential in the treatment process. 

Costs can vary from as little as $900 for the lateral suture technique, up to $6000 for the TPLO technique and that’s not considering any complications that might occur during or after the procedure. It sounds like a lot of money, but this is a very specialised technique – a similar procedure in humans would cost at least twice as much! 

Cruciate ligament disease is a condition that is usually covered by pet insurance as long as it wasn’t a pre-existing condition before taking out your policy. 

What is the success rate? 

A successful surgery is one where owners report their dog returns to complete or near-complete function. The success rate of the different surgical techniques is as follows:

• Lateral suture: 85%
• Tibial Tuberosity Advancement (TTA): 90%
• Tibial Plateau Levelling Osteotomy (TPLO): 90-95%

What are the risks or potential complications from the surgery?

Cranial cruciate surgery is a major operation and so does carry risks. The procedure is carried out under a general anaesthetic and so there are dangers associated with this; older dogs or those with concurrent health conditions will be at higher risk. 

There is also the possibility of wound breakdown or infection – proper post-operative wound hygiene is important in preventing this. This study showed that only 3% of dogs suffered from complications associates with the incisional site.

Although cruciate ligament surgery has a high success rate, there is a small possibility that the implant fails, whether that be the lateral suture rupturing or plates and screws loosening (depending on the procedure). There is also a small possibility your dog may develop a luxating patella following the surgery. It’s important to know that less all these complications occurred in less than 1% of cases and were usually easily addressable. The proper aftercare and minimising your pet’s activity following the surgery will help to prevent these complication from occurring.

What age do dogs get ACL surgery?

The age of dog has little impact on whether a dog needs ACL surgery since many other factors are involved. The average age of dog requiring ACL is about 7 years old but it can affect dogs of any age and even those as young as 6 months old. 

What other factors influence whether my dog will need ACL surgery?

In addition to age, breed and body condition score will have an impact on whether your dog needs ACL surgery. 

Larger dogs tend to be more prone to ACL rupture because they have more force going through the ligament. Breeds such as Mastiffs, Retrievers, Rottweilers, Labradors, Bulldogs and German Shepherds are more at risk but any breed of dog can rupture their ACL. 

Overweight dogs are also at a much higher risk of ACL rupture due to the increased load that the ligament must bear. Poor genetics also play a part. 

How do dogs recover from the surgery?

In the first 24 hours post-surgery it’s important that you keep your dog warm and calm; the anaesthetic drugs will be still working their way through your dog’s system so it’s normal for them to be a bit quiet. You should feed them little and often with easily digestible meals such as chicken or fish with rice. Administer any pain relief medication that your vet has provided. 

Closely monitor the incision site on your dog’s knee where the surgery was performed and contact your vet if you notice any excessive swelling or oozing from the incision site. It’s important to stop your dog from licking at the surgical site; they may need a buster collar if this is the case. Any stitches present will generally be removed at 10-14 days. 

It’s critical that your dog rests for the first 4 weeks post-surgery – crate rest is recommended. This is to reduce the movement of the knee joint to allow the bones to heal properly. Very strict short (5 minute) lead walks around the garden are allowed but jumping, running and climbing are off the cards!

From 4 weeks post-surgery onwards, you can take your dog for 2-3 walks daily. These walks can be increased in duration by 5 minutes per week, starting at 10 minute walks in week 4. It’s important to note that this is a general guide and each dog should be treated on an individual basis. After 12 weeks your dog can start off-lead exercise if the recovery is going to plan.

Dogs will likely benefit from physiotherapy or hydrotherapy during the recovery period; discuss whether this would be suitable for your dog with your vet.  

Are dogs with ACL surgery more likely to have more ACL issues down the road?

Yes, following a successful ACL injury there is a 50-60% chance that the other (non-injured) cruciate ligament will rupture in the future. This is because they’re often overcompensating with this leg, putting greater strain on the joints.  Therefore, owners must be willing to potentially repeat the process on the other leg later down the line. 

Prevention: what can owners do to avoid this surgery?

While some of the factors contributing to cruciate ligament rupture in dogs are unavoidable such as genetics and breed, many factors can be controlled. Here are some top tips for preventing an ACL tear:

• Keep your dog in shape – Excessive weight will put extra pressure on your dog’s joints, including their knees. This will wear out the ligaments faster and make them more prone to rupture. 
• Avoid high jumping – Landing wrong after a high jump puts excessive and uneven force on the knee joint. This sudden increase in pressure can be too much for the cruciate ligament to handle, resulting in rupture. 
• Regular exercise – Daily exercise is essential in maintaining strong muscles and ligaments; the stronger these are the less prone to rupture. 
• Prevent overexertion – Too much of anything can be a bad thing, including exercise. Avoid long sessions of intense exercise that involve lots of turning and jumping. Sudden changes in direction at high speeds are a recipe for a ruptured ACL. 

Example dog with ACL surgery: Charlie 

Charlie, a 6-year-old Rottweiler, presented to the clinic with a sudden onset lameness of his back right leg after having chased a tennis ball in the park. One minute he was as happy as can be, running, jumping, and diving for the ball. However, all of a sudden he yelped and refused to put any weight through his back right leg. 

The owners brought him to the vets the next day. After a short examination, it was obvious what the problem was – his knee was very unstable and he had likely ruptured his cruciate ligament. Surgery seemed like such a big step for the owners at this point and so they decided to keep Charlie well-rested for 2 weeks with pain relief. However, much to the owner’s dismay, he was no better a fortnight later. It was clear that some further investigations needed to be carried out. 

After a short anesthetic, knee and hip X-rays were taken. Marked inflammation was seen within the knee joint and some measurements were taken. An anterior cruciate ligament rupture was confirmed and the news shared with the owner. 

After some deliberation, the owners decided to go ahead with the surgery; thankfully Charlie was insured and the costs of the procedure would be covered. 

Charlie was booked in with the orthopedic vet the following week and a TPLO was performed. The surgery was a success and Charlie could immediately put weight through that leg again pain-free. After a 10-week recovery period and a gradual increase in exercise, Charlie was given the all-clear. He was very happy with his new leg! But from that point onwards, the owner was very careful not to put Charlie through any excessive exercise.