Cruciate ligament rupture Dog
Cruciate ligament rupture in dog


The anterior cruciate ligament has a special importance in the knee joint - it allows a hinge movement of the joint and prevents "sliding back and forth" of the bony structures. The cruciate ligament rupture is still one of the most common orthopedic diseases in dogs.

The diagnosis cruciate ligament rupture is a typical sports injury in humans. With our four-legged friends it behaves somewhat differently. In addition to the traumatic causes, it is usually a "degenerative process", i.e. the cruciate ligament shows signs of wear over the years, becomes thinner and thinner and finally tears. The changes in the ligament structure increase with age and with increasing body weight of the dog (negative effects are also caused by poor training).

The final tear of the cruciate ligament (cruciate ligament tear dog - we have written an extra page on the subject of cats) usually causes only minor to moderate pain. Although many dogs do not load the affected leg at all at first, an apparent improvement occurs within 2 to 3 weeks - the dogs partially load again, until suddenly another deterioration occurs: this is not infrequently the moment when the inner meniscus is massively damaged (quasi a "shock buffer" between the bony parts of the joint).

The instability of the joint causes the dog enormous discomfort, with every load the bones shift against each other - the dog feels insecure. The situation is aggravated over time by the first signs of arthrosis or a painful joint effusion.

Causes of cruciate ligament rupture in dogs

Some dog breeds are more prone to cruciate ligament tears due to their anatomy. In particular, they are more common in larger dogs such as Rottweilers, Newfoundlands and Staffordshire Terriers. Knee joint biomechanics in dogs are different from those in humans, so surgical techniques cannot simply be transferred from human medicine.

Anatomy of the knee joint

The knee joint is a hinged joint with about 30° of rotation. It consists of the thigh (femur), the tibia (shinbone), the fibula (fibula) and the patella (kneecap). The stability of the joint is provided by two straight collateral ligaments and the two cruciate ligaments. The cruciate ligaments prevent severe twisting of the knee and forward sliding of the lower leg. Between the bones are the menisci, which have shock-absorbing and stabilizing functions.

graph LR A(Anatomy of the knee joint)-->B(Thigh) A-->C(tibia) A-->D(fibula) A-->E(patella) A-->F(Ligaments) A-->G(Cruciate ligaments) A-->H(Menisci)

The cruciate ligament as one of the most important tendons of the knee

Together with the collateral ligaments, the cruciate ligaments stabilize the knee joint. Each knee joint has an outer and an inner cruciate ligament, which are actively involved in the extension of the leg. The cruciate ligament gets its name because the two ligaments cross in the middle of the knee joint. If one of the cruciate ligaments tears, the stability and mobility of the knee is severely limited.

Cruciate ligament rupture Dog
Cruciate ligament rupture dog / cat 12

The main symptoms and signs of a cruciate ligament rupture in dogs

Dogs with a cruciate ligament tear typically show difficulty in starting, a bending posture of the affected hind leg and touching the ground only with the tip of the foot. The muscles of the hind leg slacken, and when sitting, the knee is tucked under the abdomen or splayed to the side. Expressions of pain occur only when the ligament tears further.

Cruciate ligament tear dog gait

The cruciate ligament rupture dog is characterized in most cases by a so-called"start-up lameness". Depending on the degree of injury, the lameness varies. With minor tears, your dog may limp slightly for a few days and then walk normally again. Such a previous injury increases the risk of a sudden jerk if your dog moves spontaneously and jerkily. Dogs also tense their hind leg and put it in a bent position. Normally, they do not lift their paw: if at all, only the tip of the paw touches the ground.

Your dog alternates between running fast and walking very slowly. The affected leg becomes thinner due to muscle breakdown. The cruciate ligament hurts with each subsequent cruciate ligament tear dog (otherwise dogs do not show pain with degenerative tears). In a traumatic cruciate ligament tear, your dog will show sudden, severe lameness and pain at the time of the accident. Your four-legged friend stretches his leg out to the side while sitting. The knee joint is swollen. The knee of your hairy nose becomes "hot"(high heat development).

How is the cruciate ligament rupture diagnosed in dogs?

A cruciate ligament rupture test in dogs is performed with the so-called drawer test diagnosed (tibial compression test for cruciate ligament rupture dog). With this test, the veterinarian checks the mobility of the knee joint. To do this, pull the lower leg in the direction of the front legs. If the lower leg can be pulled forward like a drawer, unlike the upper leg, this indicates a tear of the anterior cruciate ligament. In addition, an effusion can be clearly felt. This test is usually easier to perform in small dogs than in larger breeds. Larger dogs have more muscle mass, which they contract during the test. For this reason, the drawer test may come back negative even if your charge has a torn cruciate ligament. An additional x-ray or CT scan will be taken to confirm the diagnosis.

How does a cruciate ligament tear occur in dogs: degenerative or traumatic cruciate ligament tear?

A cruciate ligament tear (tear) can occur in two different ways:

a) Traumatic injury

On the one hand, an injury / cruciate ligament rupture dog may occur as a result of an accident. In this case, it is called a trauma or traumatic rupture.

b) Degenerative rupture / degenerative cruciate ligament rupture dog

When the cruciate ligament tears due to long wear and tear, medical science refers to it as a degenerative rupture. Aging processes, poor posture and constant overuse can lead to tears in your dog's cruciate ligament that become deeper over time. Therefore, this type of cruciate ligament tear should be assumed to be pre-damaged. Excess weight, heavy physical exertion, or unusual tibial formation all favor degenerative cruciate ligament tears. The difference between a cruciate ligament tear in dogs and in humans lies in the intensity of the tear. In dogs, the cruciate ligament does not tear completely in most cases, but fiber by fiber (cruciate ligament tear dog hind leg).

Frequently asked questions - FAQs:

Can a torn cruciate ligament dog heal by itself?

A healing of a cruciate ligament rupture dog by itself is unlikely to impossible, the dogs during a cruciate ligament rupture rather the not damaged side increased load and thus on the not yet damaged side also damage can arise.

What happens if you do not have a cruciate ligament rupture in a dog operated on?

An untreated cruciate ligament tear can lead to arthrosis and meniscus damage and thus further aggravation of the clinical picture.

How soon does a torn cruciate ligament in a dog require surgery?

The urgency of surgery depends on several factors, including the severity of the injury, the age and general health of the animal, and individual circumstances.
In cases of complete cruciate ligament tears and in situations where conservative therapy is unsuccessful, surgery is usually required to restore joint function. The urgency of surgery varies depending on the factors listed above, but in general, surgery should be performed as soon as possible to ensure the best possible prognosis. In many cases, surgery is recommended within 1-2 weeks of diagnosis to minimize the risk of secondary damage to articular cartilage and other structures. Early intervention can help slow or prevent the development of osteoarthritis and other degenerative changes in the joint. However, in some cases, a longer waiting period before surgery may be considered, for example, if the dog is suffering from other health problems that need to be treated first.

What happens if you don't have surgery for a torn cruciate ligament?

If a torn cruciate ligament in a dog is not operated on, various complications can occur. The stability of the affected joint remains compromised, which can lead to increased instability and pain for the animal. In the long term, there is an increased risk of developing osteoarthritis and other degenerative changes in the joint. These chronic joint changes can limit the dog's mobility, reduce its quality of life, and increase the need for subsequent surgical intervention. Therefore, the decision not to have surgery for a torn cruciate ligament should be carefully considered and made in consultation with an experienced veterinarian.

Does a dog have pain from a cruciate ligament tear?

Yes, a dog may experience pain from a cruciate ligament tear. The pain results from instability of the affected joint, the inflammatory response, and possible associated injuries, such as damage to the meniscus. Pain intensity can vary depending on the severity of the injury and individual factors. Adequate treatment is therefore important to relieve pain and improve the dog's quality of life.

How much does cruciate ligament surgery cost in dogs?

Cruciate ligament rupture treatment in dogs is never a cheap affair. Simple procedures like capsular ligament repair start at 900 EUR plus physiotherapy etc. TPLO / TTA surgery start at 2500 EUR plus physiotherapy and aftercare. Artificial cruciate ligament replacement methods cost similarly, but the subsequent physiotherapy costs and medication costs are lower, as the healing time is usually much faster. Therefore we recommend dog owners of particularly endangered dog breeds (we observe cruciate ligament ruptures especially in young dogs increasingly in Labradors, Golden Retrievers, all Bulldog breeds or heavier dog breeds) to take out a surgery insurance or a veterinary health insurance at an early stage.

Cruciate ligament rupture dog surgery yes or no?

Cruciate ligament rupture dog healing time without surgery: In small dogs, sometimes conservative treatment of canine cruciate ligament rupture is possible. Non-surgical therapy includes a special diet, joint protection, physiotherapy and the administration of medication. The goal of this healing method is to allow painless weight bearing on the knee joint. However, this is not usually recommended by veterinarians. The reason for this is that if the cruciate ligament is not operated on, there is a risk of meniscus damage (cruciate ligament rupture dog without surgery). In the worst case, both cruciate ligaments of your furry nose will tear over time due to extreme overloading of the healthy, remaining ligament.
Even non-operated cruciate ligament injuries can lead to cartilage damage and osteoarthritis. Surgery has the advantage that secondary damage rarely occurs. What are the surgical techniques for a torn cruciate ligament in dogs? In the case of a torn cruciate ligament, veterinarians have a choice of several different surgical methods. On the one hand, there are techniques that use the structures of the body's connective tissue or artificial materials.

Cruciate ligament rupture dog surgery methods

The path of the many surgical methods developed for this purpose for cruciate ligament rupture led via intracapsular and extracapsular techniques to the modern conversion osteotomies. Common to all is the assessment and, if necessary, treatment of the menisci (cleaning up, meniscectomy, etc.) and, as a decisive measure, stabilization of the knee joint. A distinction is made between intra- or extra-articular techniques and those with or without ligament replacement. In our small animal center, all common and proven surgical methods are used:

  • Capsule cassia shirring according to Meutstege
  • lateral thread control and a mixture of 1&2 or
  • Zlig (formerly: VetLig - intraarticular cruciate ligament replacement) or
  • TTA Rapid or
  • TPLO

Which cruciate ligament surgery method is right for your pet?

This depends on many factors, which we will be happy to discuss with you in advance by phone without obligation after receiving your documents (below you will find an inquiry form).

The choice of surgical method depends on the patient's physical conditions (methods 1&2 are often not advisable for heavier patients), the degree of arthrosis of the joint, the involvement of the menisci and is ultimately also a question of cost. This means for you as the patient owner that together we determine the right way in the consultation .

To give you a comprehensive overview of all major surgical methods of cruciate ligament rupture in small animals (dog / cat), you will find here an overview with the respective advantages and disadvantages from our own experience (as we offer and master all methods). from our point of view:

TPLO(Tibial Plateau Leveling Osteotomy)

In this surgical method of cruciate ligament rupture, a quarter-circular bone incision is made at the upper end of the tibia. The joint surface of the tibia is then rotated backwards according to a previously calculated measure. It is fixed in this new position with a bone plate and screws. The rotation reduces the tilt of the joint surface. The goal is a postoperative inclination of 5°.

The angle between the patellar ligament and the joint surface is then about 90°. Experiments have shown that with this inclination the cranial tibial thrust is neutralized and the tension of the anterior cruciate ligament (if it is not yet completely torn) is significantly reduced.

TPLO Planning
Planning a TPLO

Advantages TPLO:

Permanent and reliable stabilization of the knee joint even under heavy load, even in animals with high body weight

For certain breeds and associated joint problems. only possible solution (especially for dogs that are generally prone to cruciate ligament tears due to their anatomy (e.g. Old English Bulldog))

the leading cruciate ligament surgery method in Germany

Disadvantages TPLO: 

X Serious surgery with sawing of the bone
X Redirection of forces in a non-natural way
X long healing process
X Relatively high price with all after roge costs like physiotherapy

TTA(Tibial Tuberosity Advancement)

A method similar to TPLO is the TTA (Tuberositas Tibia Advancement). Here, the rupture of the cruciate ligament is also used to modify the biomechanics of the knee joint by means of a bone incision. As in TPLO, a forward displacement of the patellar ligament results in an almost right angle between the patellar ligament and the tibial joint surface, as in TPLO.

Advantages TTA:

 Loading of the operated leg immediately postoperatively is somewhat faster than after a TPLO.

Disadvantages TTA:

X The load on the operated leg 1 year after a TTA is slightly worse than one year after a TPLO.
X Greater progression of knee joint arthrosis
X Significantly higher number of meniscal injuries postoperatively than after TPLO
X Less stability postoperatively than after a TPLO (current studies by Prof. Böttcher, University of Leipzig).

You can find a comprehensive comparison between the two surgical methods TPLO & TTA (classic) in the Dissertation by Dr Monika Höpfl here.


With the relatively new TTA-Rapid method, better results can now be achieved than with the classic TTA method. The success rates are comparable to the TPLO methods, which is why we will offer this method for special breeds for which the Vetlig method is not suitable.

Current studies on TTA-Rapid can be found here:

And the following study explains why the TTA Rapid implant made of pure titanium grade 1 with dodecahedron unit cell structure stimulates bone growth:

The procedure of the TTA-Rapid method can be seen in the following video:

What is the difference between TPLO and TTA?

When the veterinarian performs a TPLO, he cuts the dog's tibia with a circular incision. He then places special plates in the appropriate locations and screws the tibia and plates into a different position. The goal of this method is to prevent biomechanical slippage of the leg so that the support function of the cruciate ligament is no longer needed. In a TTA, additional plates and a spacer are screwed into the lower leg. Variations in the angle of the patellar tendon and altered fusion of bone structures also prevent sliding of the lower leg.

The advantage of both surgical techniques (over ligament replacement) is that the cruciate ligament can no longer tear because it has not been replaced. So it is possible that your dog can participate in sports and protective activities again after the healing and physiotherapy is completed. A significant disadvantage especially in very young dogs or very old: A renewed operation of the cruciate ligament is then with high probability no longer possible and in the worst case an amputation must take place. Our experience with artificial cruciate ligaments such as the Zlig or Novelig from more than 200 operations, however, is very positive. Especially in cases of bilateral cruciate ligament ruptures, our Petlig-Method® has proven its worth.

Tape replacement, extracapsular (Ruby, Tightrope, tape replacement according to Flo / Meutstege)

The extracapsular ligament replacement is used in the cruciate ligament rupture dog is often used in smaller dogs. Here, a plastic band is attached outside the joint in the direction of the anterior cruciate ligament. The method of fixation varies with each surgical method. This can be done with bone anchors in the femur and tibia (Ruby), with drilled holes in the femur and tibia (Tightrope) or on the sesamoid bone of the femur and with a drilled hole on the tibia (Flo).

Advantages ligament replacement extracapsular:

Shorter anaesthesia and surgery duration
 Lower price
 good experience with small and medium dog sizes
Faster healing process than with the aforementioned methods

Disadvantages Ligament replacement extracapsular:

X Replacement ligament can tear again just like a normal cruciate ligament
X "Wearing out" (osteolysis) of the bone drill holes in the tigthropic method with the consequence of renewed instability

Ligament replacement, intracapsular - Zlig (formerly: VetLig)

This method has been used on humans for 25 years. The body's own or artificial material (tendons, parts of the patellar ligament, fascia) is used as a ligament replacement instead of the torn cruciate ligament.

In the case of canine cruciate ligament rupture, this method did not prove successful for a long time. Due to the insufficiently controllable load on the knee joints in dogs after surgery, the ligament replacement tore again in many cases.

With the development of new materials in medical technology, it is now possible to offer dogs / cats a surgical method that is considered state of the art in humans because it best mimics the natural anatomy of the animal and, unlike TPLO / TTA, does not involve any stressful changes to the bones.

With Zlig (formerly: VetLig), a synthetic ligament for intra-articular cruciate ligament replacement in small animals is now available after long preliminary work by Dr. Jacques.Pillipe Laboureau.

A tunnel technique is used to insert the Zlig as a total replacement for the cruciate ligament. The braided extra-articular parts of the ligaments are anchored in femoral and tibial bone tunnels by canulated titanium interference screws.

This technique does not cause irreversible damage.

Advantages Zlig:

Can also be used for very heavy dogs >70kg
Reproduction of the natural anatomy without serious intervention in the bone structure
the patient's hind leg can be loaded again immediately (!) after the surgery without any risks
Lower costs than with TPLO or TTA, if you look at the total effort incl. aftercare and physiotherapy
especially with young animals This method does not obstruct the later application of Zlig or TPLO / TTA again - the latter, however, are unique and final.
a good solution in case of bilateral ligament rupture in smaller dog breeds, because then both cruciate ligaments can be replaced in one operation with one-time anesthesia risk (Petlig Method®)

Disadvantages Zlig:

X higher costs than with capsular fascia lifting according to Meutstege or lateral suture tightening

X not suitable for all breeds (see above - e.g. very rare for Old English Bulldogs)

You can find more info on our special Zlig page

We offer all the methods mentioned here and are one of the leading practices in Germany for the Zlig method.

Consultation without obligation

Here you can request a non-binding consultation with Ms. Arndt, veterinarian:

Appointment request Zlig
I am interested in information about the following cruciate ligament surgery methods (multiple choice possible):
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Maximum size of a file: 516MB
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Physiotherapy with the dog

Regardless of the surgical technique, after surgery for cruciate ligament rupture dog / cat should get painkillers your furry nose and if necessary also cartilage rebuilding preparations. The cruciate ligament rupture healing time after a TPLO is about three months. In contrast, an artificial ligament replacement has a healing time of about one month. The most important measures during the healing process are consistent physical therapy, regular weight checks, and gentle exercise and leash restriction. We have summarized more information on physiotherapeutic measures here.

Prevention of cruciate ligament rupture in dogs / Cats

If your dog currently has healthy cruciate ligaments or has already had a ligament replacement, you can take active steps to prevent a (new) cruciate ligament tear. Since overweight dogs overstress their joints and cruciate ligaments more quickly, you should make sure that your dog maintains a normal weight. In addition, you can support his joints with nutritional supplements. We will gladly tell you which are the right means. If you want to do top sports with your dog, you should pay attention to the right age. High joint stress can lead to cruciate ligament tears in both puppies and older adults. A healthy, normal-weight adult dog, on the other hand, enjoys physical activity.

To reduce the risk of your dog tearing his cruciate ligament, you should take some preventive measures:

1. weight control

Obesity is a major risk factor for cruciate ligament tears. Make sure your dog is at a healthy weight by providing him with a balanced diet and weighing him regularly.

2. regular exercise

Make sure your dog gets regular exercise to keep his muscles and joints fit. However, make sure that the activities are not too intense and avoid sudden changes of direction or jumps that could put a lot of stress on the joints.

3. non-slip floors

Avoid slippery floors in your home as they can increase the risk of injury. Use non-slip mats or rugs to provide a secure foothold for your dog.

4. early detection of joint problems

If you notice any signs of joint problems in your dog, see a veterinarian immediately. Early diagnosis and treatment can reduce the risk of cruciate ligament tears.

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