Signs of TPLO Failure in Dogs & When to See a Vet
Learn the key symptoms of TPLO failure in dogs, from limping to implant issues. Spot warning signs early and know when to seek veterinary care

Tibial Plateau Leveling Osteotomy (TPLO) is a surgery used to treat cranial cruciate ligament (CCL) injuries in dogs. Instead of replacing the damaged ligament, TPLO changes the knee's mechanics by cutting and rotating the tibia to stabilize the joint. This procedure greatly improves mobility and reduces pain, making it one of the most effective treatments for CCL injuries.
While TPLO is often successful, complications can occur. Problems may arise from surgical errors, implant issues, infections, or improper post-operative care. These issues can cause severe pain, lameness, and reduced mobility, requiring immediate attention.
Recognizing symptoms of TPLO failure early is crucial. Pet owners and veterinarians must closely monitor recovery to spot signs of complications. Identifying problems early can prevent further damage, improve treatment outcomes, and sometimes avoid the need for corrective surgery. Being aware ensures a better quality of life for the dog.
Early Warning Signs of TPLO Failure
Recognizing early symptoms of TPLO failure is crucial for timely intervention. While mild discomfort and swelling are normal during the initial recovery period, persistent or worsening symptoms may indicate complications.
Persistent Lameness or Limping
Mild lameness is expected for the first few weeks after TPLO surgery. Most dogs show significant improvement within 8–12 weeks. However, if limping persists beyond this period or worsens, it may signal poor bone healing, implant failure, or an underlying infection.
Signs of concern include the dog favoring the other leg, difficulty bearing weight, or sudden regression in mobility. If the leg does not seem to be healing as expected or if there is no gradual improvement, further veterinary evaluation is necessary. X-rays can help determine if the bone is healing correctly or if complications exist.
Read more about: Common Causes of Limping in Dogs Post-TPLO Surgery
Pain During Movement or Reluctance to Use the Affected Leg
Some discomfort is normal post-surgery, but persistent pain when walking, climbing stairs, or standing up may indicate a problem. If a dog avoids using the leg weeks after surgery or shows hesitation in movement, it could be due to implant irritation, improper bone healing, or inflammation. Pain when touching the leg, vocalization, or a stiff gait are red flags.
A dog that initially improves but later develops increased pain needs urgent assessment. A vet may perform imaging and physical exams to check for implant loosening, joint infections, or soft tissue complications affecting recovery.
Swelling Around the Surgical Site
Mild swelling is expected for a few days post-op but should gradually decrease. If swelling persists, worsens, or becomes firm and painful, it may indicate a complication. Excessive swelling could result from implant irritation, fluid buildup, or infection. If the area feels warm or if swelling is accompanied by lameness, immediate veterinary attention is necessary.
A seroma (fluid accumulation) may require drainage, while severe swelling linked to infection or implant rejection may necessitate medical intervention or revision surgery. Monitoring the surgical site daily helps detect abnormal swelling before it leads to more serious issues.
Signs of Infection (Redness, Discharge, Heat)
Post-surgical infections can occur around the incision or deep within the joint, though they are less common when Simini Protect Lavage is used, as it helps reduce bacterial contamination during surgery. However, infections can still develop due to improper wound care, immune response issues, or implant-related complications.
Early symptoms include redness, swelling, heat, and discharge from the incision site. A foul odor, increased pain, or excessive licking are also concerning. If untreated, infections can spread, leading to implant instability, fever, lethargy, and appetite loss. In severe cases, infection may require implant removal and surgical intervention.
Prompt antibiotic therapy is essential to control bacterial growth. Regular wound monitoring, proper hygiene, and early veterinary attention help prevent minor infections from escalating.
Structural and Mechanical Failures
These complications indicate that the surgical repair is not functioning correctly, leading to ongoing instability and pain. Unlike early post-op discomfort, structural failures can cause long-term mobility issues and may require corrective surgery.
Recurrent Knee Joint Instability
After TPLO, the knee joint should be stable due to the new tibial alignment. However, if a dog shows difficulty walking, wobbling, or an unstable gait, it may signal failed bone healing or implant issues. Instability can result from improper fusion of the cut tibia, loose screws, or excessive strain on the joint.
A dog may shift weight frequently or show reluctance to move, indicating mechanical failure. X-rays and physical exams help confirm whether the joint is unstable. Left untreated, instability can lead to severe arthritis, chronic pain, and reduced mobility, making early intervention critical.
Meniscal Injury or Tear
Meniscal damage is a common complication following TPLO surgery, as this cartilage helps cushion the knee joint. A torn meniscus can occur due to improper knee mechanics or residual instability. Symptoms include a sudden return of lameness, difficulty bearing weight, or a clicking or popping sound when the knee moves.
Dogs may yelp when standing or walking and may become more inactive due to pain. A torn meniscus may require surgical removal or repair to restore function. Without treatment, the condition can worsen, leading to chronic discomfort and long-term joint deterioration.
Post-Operative Meniscal Tear
A meniscal tear can occur at the time of surgery (primary tear) or develop later due to knee instability (secondary tear). A secondary meniscus tear is particularly concerning, as it often happens weeks or months after the initial procedure. This results in immediate pain, limping, and reluctance to move.
Dogs with a new meniscus tear may suddenly regress in their recovery, refusing to put weight on the leg despite previous improvements. Surgical intervention is often required to remove the damaged cartilage and restore comfort. Regular post-op checkups help detect meniscal issues before they become severe.
Implant Loosening, Bending, or Breakage
TPLO implants, including plates and screws, must remain secure for proper healing. If an implant loosens, bends, or breaks, the bone may fail to stabilize, causing pain and mobility loss. Signs include swelling, limping, reluctance to use the leg, or a clicking sensation in the joint. Implant failure can result from improper post-op care, excessive activity, or underlying bone weakness.
Overweight dogs and those resuming activity too soon are at higher risk. X-rays are necessary to confirm implant damage. Severe cases may require revision surgery to replace or secure the implants and restore knee stability.
Advanced TPLO Failure Symptoms
These symptoms indicate severe complications requiring medical intervention. If TPLO failure progresses, a dog may experience chronic pain, loss of function, or permanent joint damage. Early detection is key to preventing irreversible issues.
Delayed Bone Healing or Nonunion
Bone healing after TPLO typically takes 8–12 weeks. However, some dogs experience delayed healing or nonunion, where the bone fails to fuse properly. Causes include poor nutrition, excessive movement, infections, or improper plate positioning.
Dogs with nonunion may show persistent limping, pain, or swelling at the surgical site. X-rays can confirm if the bone is healing correctly. Nonunion requires intervention, such as adjusting activity levels, improving diet, or, in severe cases, revision surgery. If left untreated, it can lead to chronic instability and increased risk of implant failure.
Muscle Atrophy Around the Thigh
Muscle atrophy occurs when a dog avoids using the affected leg, leading to gradual muscle loss in the thigh. Mild atrophy is normal post-surgery but should improve with rehabilitation. However, progressive muscle loss suggests long-term mobility issues, improper healing, or ongoing pain. Dogs with severe atrophy may struggle with balance, fatigue quickly, or rely heavily on the other leg.
Physical therapy, controlled exercise, and pain management help restore muscle strength. If left unaddressed, muscle atrophy can make recovery difficult and reduce overall limb function, leading to permanent weakness.
Recurrent or Persistent Mobility Issues
Most dogs regain near-normal function within a few months after TPLO. However, if mobility issues persist beyond this period, it could indicate implant failure, arthritis, or joint instability. Some dogs may continue limping, struggle with stairs, or hesitate to run and jump. Persistent dysfunction suggests that TPLO did not fully correct the knee mechanics, leading to long-term discomfort.
Chronic instability may also cause secondary joint problems. Veterinary evaluation, including X-rays and orthopedic exams, is needed to determine if additional treatment or revision surgery is required. Without intervention, mobility may decline further, affecting quality of life.
Signs of Implant Failure (Mild Discomfort to Acute Pain)
Implant failure can range from mild discomfort to severe pain. Early signs include persistent limping, swelling, and difficulty bearing weight. If an implant loosens or breaks, symptoms can suddenly worsen, causing acute distress, refusal to move, or vocalization when walking. Clicking or grinding noises may also indicate implant instability.
Severe cases require urgent veterinary care, as implant failure can lead to bone fractures or infection. X-rays confirm implant integrity, and treatment may involve pain management, restricted movement, or surgical revision. Delayed care increases the risk of complications, making early detection crucial.
Potential Need for Revision Surgery
Revision TPLO surgery is necessary when the original procedure fails due to nonunion, implant failure, or chronic instability. This involves replacing damaged implants, repositioning the tibial cut, or addressing infections. Revision surgery is often more complex than the initial procedure and requires strict post-op management.
Recovery may take longer, but successful revision can restore knee stability and improve function. If left untreated, TPLO failure can result in chronic pain, severe arthritis, or loss of mobility. A thorough veterinary evaluation determines if revision surgery is the best option for improving the dog’s quality of life.
When to See a Veterinarian
Pet owners should contact a veterinarian if their dog shows signs of worsening pain, persistent lameness beyond 12 weeks, or sudden regression in mobility after initial improvement.
Other concerning symptoms include swelling that does not subside, redness or discharge from the surgical site, difficulty bearing weight, or signs of infection like fever and lethargy. Any clicking or grinding sounds from the knee may indicate meniscal damage or implant instability, requiring immediate attention.
To confirm TPLO failure, veterinarians use diagnostic tests such as X-rays to assess bone healing and implant positioning, CT scans for detailed imaging of the knee structure, and joint fluid analysis to detect infections or inflammation. In severe cases, additional tests may be needed to evaluate soft tissue damage.
Early veterinary intervention can prevent further complications, reducing the need for complex revision surgery and ensuring a better long-term outcome for the dog.
Preventing TPLO Failure
Proper post-operative care is essential for preventing TPLO failure and ensuring a smooth recovery. Strict activity restriction is crucial in the first 8–12 weeks—dogs should avoid running, jumping, or using stairs. A knee brace may provide additional joint support, especially for highly active dogs. Physical therapy helps restore strength and mobility while minimizing the risk of complications.
To promote proper healing, a nutrient-rich diet with adequate protein, calcium, and joint supplements (such as glucosamine) supports bone repair. Regular follow-up vet visits allow for X-ray monitoring to confirm bone fusion and implant stability.
Recognizing early red flags—such as persistent limping, swelling, or signs of infection—can prevent serious complications. Pet owners should check the incision site daily and report any unusual symptoms.
By following post-op guidelines and addressing concerns promptly, the risk of TPLO failure can be significantly reduced, leading to a successful recovery and long-term joint stability.
Read more about:
- Long-term outcomes of TPLO surgery
- Common myths about TPLO surgery explained
- Long-term effects of TPLO surgery on dogs
- Post-surgery recovery after TPLO in dogs
- TPLO surgery for older dogs: Is it a worthwhile option?
Conclusion
TPLO surgery is usually successful, but failures can happen due to improper healing, implant problems, or post-operative complications. Key symptoms of TPLO failure include:
- persistent lameness
- swelling
- pain during movement
- joint instability
- signs of infection
Structural issues like implant loosening, meniscal tears, or delayed bone healing can further hinder recovery.
Early detection is crucial—addressing warning signs quickly can prevent serious complications and reduce the need for additional surgery. Regular vet checkups, diagnostic imaging, and close monitoring of mobility help catch problems before they worsen.
Strict adherence to post-op care is essential in preventing TPLO failure. Pet owners should limit activity, ensure proper nutrition, and follow rehabilitation plans as advised by their veterinarian. By recognizing symptoms early and sticking to recovery guidelines, pet owners can improve their dog’s chances of a successful TPLO outcome and long-term mobility.
FAQs
What happens if TPLO fails in dogs?
If TPLO fails, the affected leg may remain unstable, leading to chronic pain, persistent lameness, and arthritis. The knee joint may not heal properly, causing difficulty in movement. In severe cases, implant failure or bone nonunion may require revision surgery to correct the issue. If left untreated, TPLO failure can significantly impact a dog’s mobility and overall quality of life.
What percent of TPLO surgeries fail?
TPLO has a high success rate, with over 90-95% of dogs recovering well. However, failure can occur in 5-10% of cases due to infections, implant loosening, meniscal injuries, or delayed bone healing. Factors like improper post-op care, excessive activity, or underlying health conditions increase the risk. Early detection and proper recovery management can reduce complications and improve surgical outcomes.
How to tell if a dog's ACL surgery failed?
Signs of TPLO failure include persistent limping, swelling, pain, and reluctance to use the affected leg beyond the expected recovery period. Clicking sounds in the joint, excessive stiffness, or visible implant issues may also indicate failure. If a dog’s condition worsens instead of improving, a vet should perform X-rays or CT scans to assess healing and detect complications.
Why is my dog limping 2 years after TPLO surgery?
Limping two years post-TPLO may result from arthritis, implant irritation, meniscal damage, or muscle atrophy. Some dogs develop scar tissue or secondary joint issues that cause discomfort. If limping is sudden, it could indicate a late meniscus tear or implant problem. A veterinary exam, including imaging, can determine the cause and guide appropriate treatment, such as pain management or revision surgery.
What does a failed TPLO look like?
A failed TPLO often presents as persistent pain, joint instability, swelling, or difficulty bearing weight on the affected leg. Dogs may show progressive lameness, reluctance to move, or audible joint clicking. Severe cases may involve implant loosening, infection, or nonunion of the bone, which can be confirmed through X-rays or CT scans. Early intervention is crucial to prevent worsening complications.
Can TPLO surgery be redone?
Yes, revision TPLO surgery can be performed if the initial procedure fails. This may involve removing or replacing implants, repositioning the tibial cut, or addressing infections. Revision surgery is often more complex and requires strict post-op care. In some cases, alternative treatments like custom knee braces or joint fusion procedures may be considered if TPLO cannot be successfully redone.
What is the alternative to TPLO on dogs?
Alternatives to TPLO include Lateral Suture Stabilization (Extracapsular Repair), Tibial Tuberosity Advancement (TTA), and CBLO (Cora-Based Leveling Osteotomy). These procedures also stabilize the knee but may be better suited for smaller dogs or specific cases. Non-surgical options like custom braces, weight management, and physical therapy may help in mild or inoperable cases, though they do not provide the same level of stability as TPLO.
How long can a dog go without TPLO surgery?
Dogs with a torn CCL can survive without TPLO, but untreated ligament injuries lead to chronic pain, arthritis, and joint deterioration. Some small or inactive dogs may adapt with braces, weight control, and pain management, but larger, active dogs usually require surgery for long-term stability. Without intervention, progressive joint damage can severely impact mobility, making walking difficult or painful over time.
Get a Free Poster
Enhance your workspace with a high-quality radiographs reference poster, designed for veterinary professionals. This free physical poster will be shipped directly to you—just fill out the form to request your copy.
Step #1
Getting Ready
Ensuring a clean surgical field starts with proper skin preparation. This video demonstrates the best practices for:
- Shaving the patient – Achieving a close, even shave while minimizing skin irritation
- The Dirty Scrub – The initial skin prep step to remove surface debris and reduce bacterial load before the sterile scrub.
Following these techniques helps reduce infection risk and improve surgical outcomes. Watch the video to see how it’s done effectively!
Step #2
Reduce Your Risks
Many surgeons are shocked to find out that their patients are not protected from biofilms and resistant bacteria when they use saline and post-op antibiotics.
That’s Where Simini Comes In.
Why leave these risks and unmanaged? Just apply Simini Protect Lavage for one minute. Biofilms and resistant bacteria can be removed, and you can reduce two significant sources of infection.
Step #3
Take the Course
Preventing surgical infections is critical for patient safety and successful outcomes. This course covers:
- Aseptic techniques – Best practices to maintain a sterile field.
- Skin prep & draping – Proper methods to minimize contamination.
- Antibiotic stewardship – When and how to use perioperative antibiotics effectively.
Stay up to date with the latest evidence-based protocols. Click the link to start learning and earn CE credits!
