What Happens if the Cruciate Rupture is Not Surgically Repaired

Without an intact cruciate ligament, the knee becomes unstable, leading to abnormal wear on the bones and meniscal cartilage. Over time, the joint undergoes degenerative changes, with bone spurs (osteophytes) forming, causing chronic pain and reduced mobility. While surgery can help stabilize the joint and slow this progression, it cannot reverse the damage already done.

• In some patients, osteophytes can begin forming as early as one to three weeks after a cruciate ligament rupture. While all dogs will eventually develop degenerative joint changes, large-breed dogs tend to struggle more with the condition. Initially, a dog may seem to improve after several weeks, but full, long-term recovery back to normal function without intervention is unlikely.
  
• A study followed a group of dogs for six months after a cruciate ligament rupture. By the end of the study, 85% of dogs weighing less than 15 kg had regained near-normal or improved function. In contrast, only 19% of dogs over 15 kg achieved similar recovery. Regardless of size, both groups required at least four months to reach their maximum level of improvement.

What Happens in Surgical Repair?

There are three different surgical repair techniques commonly used today.

Extracapsular Repair

This procedure is the traditional surgical approach for repairing a cruciate rupture. It involves creating an artificial ligament on the outside of the joint. While this was once the primary method of repair, it is now understood that, regardless of the material used, the artificial ligament begins to loosen within two months.

In this procedure, the first step is to open and inspect the knee joint—an essential part of any knee surgery. The torn or partially torn cruciate ligament is then removed, and any significant bone spurs are trimmed using a specialized instrument called a rongeur. If the meniscus is damaged, the affected portion is excised. To stabilize the joint, a strong suture is looped around the fabella behind the knee and threaded through a hole drilled in the front of the tibia. This tightens the joint, preventing the abnormal drawer motion and effectively taking over the function of the cruciate ligament.

• After surgery, the dog may keep the leg lifted for about two weeks. However, knee usage gradually increases over the following two months, with most dogs eventually returning to normal function..

• After surgery, the dog typically requires 8 to 12 weeks of restricted exercise, including no running and only being taken outside on a leash, even in the backyard.
  

• The suture used in surgery will gradually loosen and break within 2 to 12 months, at which point the dog's own healed tissue will support the knee.

Tibial Plateau Leveling Osteotomy (TPLO)
This procedure takes a fresh approach to knee joint biomechanics and was initially designed for larger breed dogs. However, it is now recognized as the preferred surgical option for both large and small breeds. Compared to extracapsular repair and TTA, this is the only procedure that significantly slows the progression of arthritis in most dogs.
This procedure alters the angle at which the femur applies weight to the flat "plateau" of the tibia. By cutting and rotating the tibia, the dog's natural weight-bearing forces help stabilize the knee joint. As with other knee surgeries, the joint must be opened, and any damaged meniscus removed. The remnants of the cruciate ligament may be left intact or removed, depending on the extent of the damage.
This surgery is complex and requires specialized training in the technique. Multiple radiographs are needed to accurately calculate the osteotomy angle (the cut in the tibia). While this procedure is more invasive than extracapsular repair and typically more expensive, it offers significantly superior results.

• Most dogs typically begin touching their toes to the ground within 10 days after surgery, though in some cases, it may take up to three weeks.
• As with other surgical techniques, exercise must be restricted for 8 to 12 weeks.
• Most dogs regain full function within 3 to 4 months after surgery and can gradually return to normal activity.
• Athletic dogs experience the best outcomes with this surgery.

Tibial Tuberosity Advancement (TTA)
The TTA (Tibial Tuberosity Advancement) procedure also utilizes knee biomechanics to enhance stability but does so by altering the angle of the patellar ligament. This is achieved by cutting and repositioning the tibial crest, where the patellar ligament attaches, and securing it with a titanium or steel "cage," "fork," and plate, along with bone grafts to maintain the new alignment. Like the TPLO, this procedure involves cutting bone and requires specialized equipment, including metal implant plates. Recovery is similar to that of the TPLO, but the TTA does not slow the progression of arthritis as effectively.

Which Procedure is Better?

​The TTA and TPLO procedures are more invasive, costly, and require specialized equipment and trained personnel. They also carry a higher risk of complications. Are they worth it? Despite the differences in surgical approach, studies suggest that one-year post-operative outcomes are similar across all three procedures—extracapsular repair, TPLO, and TTA. However, arthritis progresses much more rapidly with the extracapsular technique and TTA compared to TPLO. In the long run, joint health is significantly better with TPLO, and some evidence suggests that dogs may return to normal function more quickly with this procedure.

How is the TPLO performed?
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Q: Does My Dog Really Need Surgery?  I Read That They’ll Do Just Fine Without Surgery.

A: Published studies indicate that about 15% of dogs can regain reasonably good clinical function without surgery, with most of these cases being small breeds weighing under 7 to 10 kg. Dogs that do recover normal function typically do so within 4 to 6 weeks after the initial onset of lameness. However, for the majority of dogs, surgery is the only reliable way to restore proper function—braces, medications, herbs, physical therapy, or simply hoping for improvement are not effective alternatives.

Q: Which Patients Will Benefit From TPLO?

A: Although TPLO can be performed on almost any patient, including small dogs and cats, it is particularly beneficial for larger, active breeds. While opinions among surgeons may vary, most agree that smaller dogs tend to have similar outcomes regardless of the surgical technique used. In general, dogs weighing over 20 kg (45 pounds), especially those with high activity levels, experience the greatest benefits from TPLO.

Q: Why Is TPLO So Costly, Especially When Compared To Other Cruciate Repair Surgeries?

A: TPLO requires specialized equipment, including a motorized bone saw with a uniquely designed curved blade, a stainless steel bone plate, and 6 to 9 bone screws. The procedure also involves taking 4 to 6 X-rays and demands extensive training for the surgeon. Each surgery requires a significant time investment, with preparation, operation, and recovery taking approximately 2 to 4 hours per patient.

Q: What Aftercare Is Required?

A: Surgeons take different approaches to post-operative care, and there is no definitive evidence to determine the best method. Some recommend strict rest, limiting stair climbing, and kenneling when unsupervised. Others encourage controlled leash walks and moderate exercise, while some advocate for immediate post-surgical physical rehabilitation. Regardless of the approach, follow-up X-rays are necessary at various stages to monitor bone healing. Once the bone has fully healed, exercise can be gradually increased to normal levels.

Q: What About Possible Complications?

A: TPLO is a major surgical procedure, and complications can occur. Research suggests that complication rates may be slightly higher than with less invasive surgeries, though factors such as patient characteristics and surgeon experience also play a role. Most complications are minor and can be managed without additional surgery, leading to successful outcomes. These include issues like infections and patellar tendon inflammation.
More serious complications, such as plate or screw failure and fractures of the tibia or fibula, are uncommon. There have also been rare cases of bone cancer developing months or years after surgery in the operated area. However, the connection between TPLO and bone cancer remains controversial, as the upper tibia is a common site for this cancer in dogs, even in those without prior surgery or cruciate issues. Whether TPLO increases this risk is unclear.
One of the most frequent post-operative complications is not directly related to TPLO itself. Meniscal cartilage tears are a common consequence of an unstable joint and may be present at the time of surgery or develop later. Up to 11% of dogs experience new meniscal tears post-surgery, similar to rates seen in humans undergoing knee surgery. These dogs often recover well after surgery but may suddenly become lame again weeks or months later due to a meniscal tear.
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Q: Is TPLO Really Better Than Other Surgical Options?
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A: If your dog is large, young, and active, the answer is likely yes—TPLO is the best option. However, the supporting research has not always been conclusive. For the first 20 to 25 years after TPLO was developed, surgeons observed significantly better outcomes in large dogs compared to other surgical techniques. Yet, early research data didn’t seem to confirm these findings.One major factor was Dr. Barclay Slocum’s decision to patent the TPLO technique and equipment, which limited access to the procedure and subsequently restricted research opportunities. Additionally, veterinary research is inherently more limited in scope compared to human medicine. While studies in the New England Journal of Medicine often involve tens or even hundreds of thousands of human patients, veterinary studies are typically much smaller—considering a study with 50 animals to be substantial. The reason? Funding. The financial resources available for veterinary research are vastly smaller than those in human medicine.
In recent years, however, research has begun to validate what surgeons have long observed: dogs undergoing TPLO recover faster, develop less joint arthritis, and achieve better long-term function compared to other surgical techniques. Current evidence indicates that TPLO provides superior outcomes over TTA and extracapsular repair. While definitive conclusions are still being drawn, it appears that other similar procedures, such as CWO, CBLO, and TTO, may also offer similar benefits.
         

​So your pet is booked in for a general anaesthetic, I’m sure you now have a few questions about what that means and what you need to do. There’s no need to be too worried, hopefully you can find all your answers below but if not don’t hesitate to give the clinic a call to ask any questions that you need.

​An anaesthetic is when drugs are used to make your pet unconscious and unaware of what is happening. First we give your pet some drugs to make them relaxed and provide some pain relief in preparation for the procedure. The particular drugs 

​Your vet may or may not want you to give your pet its usual medication just before the procedure depending on what it’s on. Therefore if your pet is on long term medication make sure you check with your vet before if they want you to give it or not. 

​We admit patients for procedures between 8am and 9am so bring your pet down between these times. Make sure you dog has been for a toilet walk before hand and be prepared to stay for a little while when you drop your pet as the nurses will have a couple of questions for you. It’s really important that if your pet has been unwell at all in the days leading up to the procedure that you let us know. Sometimes we might feel it is safest to delay the procedure if your pet has been unwell. 

​There is a very small inherent risk associated with any anaesthesia, just as there is with people. The more details we have about your pet’s health on the day of the procedure the safer we can make it for your pet. Having said that the vast majority of procedures go really well and you shouldn’t be spending the whole day worrying. Monitoring your pet during the anaesthesia allows us to adjust what we’re doing to your pet’s individual needs.

​We usually ask that you give us a call between 2-4pm to check how everything has gone and organise a time to come back in and pick up your pet. 

At Northern Territory Veterinary Services, we are seeing many dogs in the NT getting sick from a relatively easily preventable illness. Pups are in particular danger of dying from this disease. What’s an even more concerning development is that we recently are seeing adult dogs succumbing to this horrible illness.  What is it? Hookworms. Yes! Hookworms. There are several worms that can cause health problems but recently hookworms have been rearing their ugly heads. We have seen an unusual number of worm infested dogs, especially puppies. Regular worming is easy to forget but it is so important to keep your pets healthy, both in the young and old.
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So what’s so unusual about this wet season? Well, we see a lot of these infections in the wet as the worms require water droplets to hatch out. So this wet season being particularly big and particularly long, we are seeing heavier burdens and greater number of animals affected.

​What is hookworm?
The hookworm is a particularly nasty parasite (about 3mm long) that hooks onto the inside of the intestinal wall and sucks out a large amount of blood to feed.  Puppies can become infected before birth, through the milk when feeding from their mum, or through the skin from the environment. This worm causes blood loss, weight loss, pain, failure to thrive and in severe cases, death.  Unfortunately, hookworm infestation is usually first noticed when the pup is already very sick with very pale gums, lethargy or bloody diarrhoea. Adult dogs are more resistant but we do diagnose infections in them too, particularly when the environmental conditions are right. They can cause a more slow lingering illness in adult dogs.

Can I catch it?
Hookworm is transmissible to humans. Personal hygiene is always important;- wash your hands after handling your dog and definitely before eating, Hookworm larvae can also hatch out in the yard and then burrow through the skin and cause itching. Children are particularly at risk. 

So how do we do we stop the cycle of infection?
Prevention is the best cure, and regular worming of all your dogs throughout their lives will help stop the vicious cycle of re-infection.
Puppies must be wormed from 2 weeks of age and every 2 weeks until they are 12 weeks old then every month until 6 months of age.  From then on, worming every 3 months is adequate, unless otherwise advised. Talk to one of our veterinarians for further advice. Over time, with regular worming, your dogs can act as vacuum cleaners for the yard and clean up the environment.
Cats don’t get hookworm but they are at risk of other intestinal worms, and so they should have a regular worming routine as well. Luckily for those slightly less sociable puddytats, there are effective top spot all wormers available now from vets. Phew!

​New dog? What to do…
When you pick up a new puppy make sure the breeder gives you information on when the puppy was wormed and what was used. If they cannot do this, it is best to assume the pup hasn’t been wormed. Any new dogs or pups should be wormed as soon as possible to avoid infecting your own yard with worms.
 
If in doubt, just ask
If you have a new puppy or are planning to breed, call into your local veterinary clinic and speak to the staff who can give you the correct advice on prevention and treatment of worms in your dog.

For further information, call us on 08 89723599 in Katherine or 08 89524353 in Alice Springs at Northern Territory Veterinary Services.