Tibial Plateau Leveling Osteotomy (TPLO)
Surgical Treatment for Ruptured Cranial Cruciate Ligament
What is Cranial Cruciate Disease
Cranial cruciate ligament (CCL) disease is the most common cause of hind limb lameness in dogs. The CCL plays a crucial role in stabilising the stifle (knee) joint, and its rupture can result in the knee joint hyperextending, rotating, and the shin bone moving forwards relative to the thigh bone. This instability leads to significant pain, lameness, and eventual osteoarthritis if left untreated.
Trauma and age-related degeneration of the ligament are the two main causes of rupture, and these can be influenced by age, activity levels, obesity, genetics and breed. Degeneration of the ligament is much more common and results in intermittent bouts or chronic low grade lameness which eventually leads to non-weight bearing lameness when the ligament finally ruptures.
The most effective surgical technique to treat this condition is Tibial Plateau Levelling Osteotomy (TPLO).

What is TPLO?
The top of the tibia has a natural slope upon which the femur sits. When the cruciate ligament – which attaches the tibia to the femur – is ruptured, the femur falls down this slope, resulting in instability and pain.
The aim of a TPLO surgery is to reduce this slope and thereby reduce or eliminate the instability.
TPLO involves making a circular cut around the top of the tibia and rotating it so its contact surface is level. A bone plate with screws is placed to stabilise the bones in the new alignment. This makes the knee more stable, despite not having an intact CCL.
How is Cranial Cruciate Ligament Rupture Diagnosed?
The first suspicion of an injured CCL is any dog with a limp in a hind leg. Some signs can be subtle and ongoing or recurring if there is only a partial injury. Other animals can develop a sudden-onset lameness and don’t want to put any weight on their leg. It is not uncommon for a dog to have cruciate disease in both legs, and these dogs have difficulty getting up and don’t want to walk far.
Signs you may notice include:
- Sudden onset lameness
- Limping when exercising
- Limping after waking up and difficulty rising
- Reduced activity levels, depression and lethargy
- Swelling around the knee
On examination we may be able to detect:
- Pain on manipulation of the knee joint
- Joint effusion
- Thickened and swollen joint
- No pain or abnormalities anywhere else in the leg
Confirmation of the diagnosis requires sedation to obtain x-rays and examine the knee joint when the patient is relaxed and pain-free. X-rays can confirm joint effusion (swelling), detect supporting signs of osteoarthritis and eliminate other causes of pain in the knee.
The definitive test is detecting the femur sliding down the tibial plateau which can only happen if the ligament is ruptured. Partial tears will give a positive “Cranial Drawer test”. In cases of a full rupture, a dog will also have a positive “Tibial Thrust” test.
What Patients will Benefit from TPLO?
TPLO can be performed in most sizes of dog, but is especially suited to medium to larger breeds of dogs, especially if they are quite active.
As a general rule a TPLO is best suited for dogs over 15-20kg, but this is assessed on a case-by-case basis.
Dogs less than this weight can do quite well on other techniques such as a lateral stabilisation, and dogs heavier than this tend to have poorer responses to lateral stabilisation, and can develop arthritis in this joint at an earlier age.
With a TPLO surgery, dogs are less painful in the immediate post op period, are faster to regain function in the affected leg, and will develop osteoarthritis later in life compared to conservative treatment or other surgical techniques.
TPLO at Wigram Vets
Dr Christina Morris, DVM, MVM (Dist. CA Surgery), CCRP, performs TPLO surgeries using the OssAbility Guided TPLO system.
Using x-rays provided by us, an expert case-by-case report is provided to take the guesswork out of surgical planning and can identify patient-specific risk factors to minimise the risks of complications.
Post-Operative Care
TPLO surgery has a high success rate, especially if appropriate post op care is taken.
Most animals will be able to walk out of the clinic and bear weight on the leg quickly after the procedure. We use a multi-modal pain control approach which starts before the surgery, includes epidural anaesthesia and is continued following the surgery.
Physiotherapy is very important for a successful outcome and speeding up the recovery process, and is tailored on a case-by-case basis. Included in our surgical package are 8 weekly sessions with our rehab practitioner, Kate Donald, BSc PGDipSciComm. Once we are happy the wound has healed after 10-14 days, Kate will continue the rehab and recovery treatment which includes laser therapy, massage therapy, balance and strength training and the use of the underwater treadmill.
8 weeks following the surgery we x-ray the leg to confirm bony healing has completed, which is also included in the surgical package. From here there is a gradual increase in the amount of exercise with the expectation of being completely normal by the 5-6 month mark.
Complications
Complications are uncommon but can occur with any surgical procedure. These include infection, progression of arthritis, injury to the meniscus within the joint, fracture around the implant, loosening of the implant and patella luxation.
If you have any questions regarding cruciate disease or TPLO, please don’t hesitate to contact Christina.