Patellar tendonitis more precisely called patellar desmopathy or patellar ligament desmitis in veterinary literature is a recognized complication of TPLO surgery. It is also one of the most under-discussed.

Research published in PMC shows radiographic evidence of patellar ligament thickening in 93% of dogs at 4 weeks after TPLO, though most cases are asymptomatic.

Understanding what this condition is, when it becomes a clinical problem, and how it is treated helps owners navigate one of the more commonly missed post-TPLO findings.

Quick answer: Patellar desmitis after TPLO is inflammation and thickening of the patellar ligament. Radiographic thickening occurs in 93% of TPLO dogs at 4 weeks but is usually asymptomatic. Clinically significant cases cause pain and increased lameness. Most are self-limiting; shock wave therapy accelerates resolution.

Key takeaways

• Radiographic patellar ligament thickening occurs in 93% of TPLO dogs at 4 weeks: most are asymptomatic and self-limiting
• Clinically significant patellar desmitis causes pain, swelling, and increased lameness beyond expected post-op discomfort
• TPLO changes stifle biomechanics and increases patellar tendon load: this explains why desmitis occurs more after TPLO
• Shock wave therapy (SWT) significantly reduced patellar ligament thickness at weeks 6 and 8 in a 2012 clinical trial
• Most cases are self-limiting: rest and NSAIDs resolve the majority of clinically significant cases within weeks to months
• Excessive post-operative activity is a modifiable risk factor: strict restriction in the first 8 weeks reduces desmitis risk

What is patellar desmitis after TPLO?

The patellar ligament runs from the kneecap (patella) to the tibial tuberosity — the bony bump just below the knee on the front of the tibia.

It is a critical structure for leg extension and stifle stability.

After TPLO surgery, the biomechanics of the stifle change fundamentally. The tibial plateau is rotated and held at a new angle.

This changes how forces are distributed around the knee, including the forces that pass through the patellar ligament.

The patellar ligament experiences altered tension and loading patterns after TPLO that it did not experience before surgery.

PMC research (2025 retrospective study) confirms desmopathy typically develops within 2.5 months after surgery, affecting the distal portion, and that TPLO causes more ligament thickening than other CCL repair methods.

A separate PMC study using elastosonography confirmed that patellar tendon tendinopathy can be easily detected clinically but that the exact damage evaluation is challenging without ultrasound or advanced imaging.

Why does TPLO cause patellar tendonitis?

Several mechanisms contribute:

Altered stifle biomechanics: TPLO changes the angle of the tibial plateau and the position of the tibial tuberosity relative to the femur. This alters patellar tendon geometry and tension during weight-bearing.

Surgical trauma: retraction and manipulation of soft tissues around the tibial tuberosity during the procedure causes local inflammatory changes that can involve the patellar tendon.

Intraoperative tension increase: rotating the proximal tibial segment may change the tension in the patellar tendon directly, especially during the initial healing phase.

Excessive postoperative exercise: Clinicians Brief's treatment review notes that excessive postoperative exercise is a commonly proposed contributing factor. Dogs allowed too much activity too early are more likely to develop clinically significant desmitis.

How common is patellar desmitis after TPLO?

Radiographic evidence of patellar ligament thickening at 4 weeks post-TPLO is reported in 93% of dogs in clinical studies.

The vast majority of these dogs have no clinical signs the radiographic finding does not translate into a symptomatic problem for most patients.

Clinically significant desmitis where the dog shows pain and lameness attributable to the patellar ligament specifically is less common but well-recognized by veterinary orthopedic surgeons.

Laguna Hills Animal Hospital notes that patellar tendinosis is relatively benign in most cases and improves with rest and medication.

Signs of clinically significant patellar desmitis

Unlike the asymptomatic radiographic finding, clinical patellar desmitis produces:

• Pain on direct palpation of the patellar ligament (between the kneecap and tibial tuberosity)
• Swelling or thickening directly over the ligament
• Lameness that is worse than expected for the dog's recovery stage
• Reluctance to fully extend the stifle during walking or exercise
• Stiffness after rest that improves briefly with movement

These signs typically appear in the first 6 to 10 weeks after TPLO.

Diagnosis

A veterinarian diagnoses patellar desmitis through:

Physical examination: palpation of the patellar ligament for thickening, pain response, and heat. A dog with significant desmitis will react to direct pressure on the ligament.

Radiographs: thickening of the soft tissue shadow over the patellar ligament on a lateral stifle projection. This is often identified at the routine 4 to 6 week post-TPLO radiographic recheck.

Ultrasound: provides direct visualization of the ligament, showing thickening, fiber disruption, and periligamentous edema. Ultrasound is more sensitive than radiographs and is the preferred modality for detailed assessment.

Treatment

Rest and activity restriction

The foundation of treatment for most cases. Reducing the mechanical load on the patellar ligament allows the inflammatory process to resolve.

Strict activity restriction should already be in place for post-TPLO recovery patellar desmitis is a reason to enforce it rigorously.

NSAIDs

Anti-inflammatory medication reduces pain and local inflammation. Meloxicam or carprofen at appropriate veterinary doses is the standard pharmaceutical approach for most dogs with symptomatic desmitis.

Shock wave therapy (SWT)

Clinicians Brief reviewed a trial of 30 large-breed TPLO dogs: SWT at weeks 4 and 6 significantly reduced patellar ligament thickness on radiographs at weeks 6 and 8 vs. controls.

SWT should be considered for dogs with clinically significant patellar desmitis.

Laser therapy

Low-level laser therapy (photobiomodulation) may reduce local inflammation and support tissue healing, though evidence specific to patellar desmitis after TPLO is limited compared to the SWT evidence base.

For the complete TPLO complications reference, see 15 common complications after TPLO surgery in dogs. For the incision infection guide, see TPLO incision infection symptoms and prevention.

For the general lameness guide that helps distinguish desmitis from other causes of post-TPLO lameness, see lameness after TPLO surgery in dogs.

For the TPLO failure rate context, see TPLO failure rate in dogs explained.

Frequently asked questions

Is patellar tendonitis after TPLO serious?

In most dogs, no. The radiographic finding is near-universal but typically asymptomatic and self-limiting.

Clinically significant desmitis causes pain and increased lameness but usually resolves with rest, NSAIDs, and sometimes shock wave therapy. It rarely causes permanent dysfunction.

How do I know if my dog has patellar tendonitis vs. normal post-TPLO soreness?

The key distinguishing feature is pain specifically on palpation of the patellar ligament the structure running from the kneecap to the bump just below the knee.

Normal post-TPLO soreness is diffuse and improves steadily. Patellar desmitis produces focal pain at this location, often with visible swelling over the ligament.

Can patellar desmitis be prevented?

Strict activity restriction in the first 8 weeks post-TPLO is the most effective preventive measure, since excessive early activity is a recognized contributing factor.

It cannot always be prevented altered biomechanics from the surgery itself play a role regardless of activity level but minimizing mechanical load during the healing phase reduces severity.

Does patellar tendonitis require a second surgery?

Almost never. The vast majority of cases resolve with conservative management. Shock wave therapy is effective in cases that need more active treatment.

Surgical intervention for patellar desmitis after TPLO is extremely rare.

Will this affect my dog's long-term outcome after TPLO?

For most dogs, no. Clinically significant patellar desmitis is typically a temporary complication that resolves during the recovery period.

Long-term stifle function in dogs that develop and recover from patellar desmitis is generally comparable to dogs that do not develop the condition.

Resources

• PMC. Retrospective Study on Patellar Desmopathy Following Surgical Resolution of CCL Rupture in 28 Dogs. ncbi.nlm.nih.gov
• PMC. Radiographic, Ultrasonographic and Shear Elastosonographic Changes in Patellar Ligament in Dogs Undergoing TPLO. ncbi.nlm.nih.gov
• Clinicians Brief. Treating Patellar Ligament Desmitis. cliniciansbrief.com
• Laguna Hills Animal Hospital. TPLO Surgery Complications. lhah.com
• ACVS. Cranial Cruciate Ligament Disease. acvs.org

TPLO surgery requires general anesthesia that is tailored to the individual patient. For most healthy adult dogs, TPLO anesthesia is straightforward and low-risk.

For older dogs, obese dogs, or those with concurrent medical conditions, the anesthetic plan requires additional planning.

Understanding what the protocol involves helps owners know what to expect and how to prepare their dog.

Quick answer: TPLO anesthesia includes a preoperative blood panel; premedication with an opioid and sedative; induction with propofol or alfaxalone; maintenance with isoflurane or sevoflurane; continuous monitoring; and multimodal pain management including NSAIDs, nerve blocks (sciatic/femoral or epidural), and post-operative opioids.

Key takeaways

• Preoperative blood work is standard for all TPLO patients: CBC and biochemistry identify organ dysfunction and conditions that increase anesthetic risk
• TPLO anesthesia is multimodal: combining opioids, NSAIDs, nerve blocks, and inhalant anesthetic reduces total drug doses and improves pain control
• Nerve blocks are now standard in TPLO anesthesia: femoral and sciatic blocks with bupivacaine reduce post-operative opioid requirements
• A published feasibility study achieved total opioid-free post-operative analgesia in TPLO dogs using nerve blocks, ketamine, isoflurane, and meloxicam
• Epidural analgesia reduces post-operative opioid requirements by 36% compared to no epidural, per PMC study data
• Food is withheld 8 to 12 hours before surgery to reduce aspiration risk; water restriction is typically shorter

Pre-anesthetic assessment

Every dog undergoing TPLO is evaluated before anesthesia to identify risk factors and optimize the anesthetic plan.

Physical examination: body weight, cardiovascular and respiratory status, mucous membrane color and capillary refill, hydration status, and assessment of concurrent conditions.

Blood work: complete blood count (CBC) detects anaemia, infection, and platelet abnormalities. Biochemistry panel assesses kidney function (creatinine, BUN), liver function (ALT, ALP, bilirubin), blood glucose, and electrolytes. These results determine anesthetic drug selection and guide fluid therapy.

ASA classification: anesthesiologists use the American Society of Anesthesiologists (ASA) physical status classification (1 to 5) to communicate overall health status. Most TPLO patients are ASA class 1 (healthy) or 2 (mild systemic disease). Dogs with significant cardiac, renal, or hepatic disease may be ASA 3 or higher and require additional monitoring or modified protocols.

Premedication

Premedication is given 20 to 40 minutes before induction.

It serves to calm the dog, reduce anxiety, provide early analgesia (preemptive analgesia), reduce the amount of induction and maintenance agent required, and make induction smoother.

Opioids (most common premedication component for TPLO):

• Hydromorphone: commonly used as a premedication; the PubMed perioperative analgesia study used hydromorphone plus acepromazine as premedication in all 56 TPLO dogs
• Methadone: provides both opioid analgesia and NMDA receptor antagonism; commonly used as a premedication in many European centres
• Morphine: used in some protocols, particularly when combined with epidural administration

Sedatives:

• Acepromazine: a phenothiazine tranquilizer that provides reliable sedation; use is reduced in patients with cardiovascular compromise due to vasodilatory effects
• Medetomidine or dexmedetomidine: alpha-2 agonists providing sedation, analgesia, and muscle relaxation; used in the opioid-free feasibility protocol (PMC 2024)
• Midazolam: benzodiazepine used particularly in geriatric or debilitated dogs for its minimal cardiovascular effects

Anesthetic induction

Induction agents produce rapid unconsciousness, allowing placement of an endotracheal tube for airway control.

Propofol: the most commonly used induction agent in healthy dogs. Provides smooth, rapid induction with a short duration, making induction-to-intubation management easy.

Alfaxalone: a neuroactive steroid with a similar profile to propofol. Used in some protocols as an alternative, particularly in smaller dogs or where propofol is not available.

Ketamine + midazolam: used in some protocols as an alternative induction combination, particularly when some degree of analgesia is desired at induction. Also used in opioid-sparing protocols.

Intraoperative maintenance

Inhalant anesthetics (isoflurane or sevoflurane) are delivered via endotracheal tube to maintain unconsciousness throughout the surgery.

Isoflurane is the most widely used agent in veterinary anaesthesia for TPLO. Sevoflurane provides faster recovery but is more expensive. Both are effective.

IV constant rate infusions (CRI) during surgery augment inhalant anesthesia and reduce inhalant requirements:

• Ketamine CRI: used in opioid-sparing protocols; the PMC feasibility study used ketamine CRI at 0.6 mg/kg/h throughout surgery
• Morphine-lidocaine-ketamine (MLK CRI): a well-established combination providing balanced intraoperative analgesia with reduced inhalant requirements
• Fentanyl CRI: an opioid CRI providing titratable intraoperative analgesia

Regional analgesia (nerve blocks)

Nerve blocks have become a key component of TPLO anesthesia because they provide superior post-operative pain control compared to systemic opioids alone.

Femoral and sciatic nerve blocks (FSNB): block the main sensory nerves to the stifle joint and hind limb. Performed before surgery with bupivacaine. PMC research comparing nerve blockade approaches for TPLO confirms that femoral and sciatic nerve blocks provide superior postoperative analgesia compared to IV CRI alone.

Lumbosacral epidural: injection of morphine and bupivacaine into the epidural space. PMC data (epidural + liposomal bupivacaine study) found epidural analgesia produced 36% fewer post-operative opioid injections compared to no epidural.

Intra-articular injection: bupivacaine injected directly into the stifle joint before or after surgery. Used as an alternative or supplement to nerve blocks in some protocols.

Intraoperative monitoring

Standard TPLO monitoring includes:

• ECG: continuous heart rate and rhythm monitoring
• Pulse oximetry (SpO2): peripheral oxygen saturation
• Capnography (end-tidal CO2): assesses ventilation adequacy; dogs are often placed on mechanical ventilation during TPLO
• Blood pressure: direct arterial or indirect Doppler/oscillometric
• Temperature: hypothermia is a common complication of long anesthetic events; warming devices are used routinely
• Depth of anesthesia assessment: clinical signs including eye position, jaw tone, and response to surgical stimulation

Post-operative pain management

TPLO is a significant orthopedic procedure and post-operative pain management directly affects recovery quality and rate of return to function.

NSAIDs: meloxicam or carprofen are administered in the peri-operative period and continued at home for 7 to 14 days minimum. The PMC opioid-free protocol administered meloxicam 0.2 mg/kg IV intraoperatively.

Opioids: hydromorphone or buprenorphine for 24 to 48 hours post-operatively, reducing as the nerve block wears off and NSAID analgesia covers the residual pain.

Gabapentin: increasingly prescribed for the first 1 to 2 weeks post-operatively to address neuropathic pain components associated with the surgical trauma and healing nerve tissues.

For the full recovery guide and what to expect after waking up, see what to expect after TPLO surgery in dogs.

For the leg shaking guide that often relates to anesthetic recovery, see dog leg shaking after TPLO surgery.

For the incontinence guide related to catheterization and anesthesia effects, see dog incontinence after TPLO surgery. For the post-surgical pain guide, see dog whining after TPLO surgery: causes and care.

Frequently asked questions

Is TPLO anesthesia safe for dogs?

For healthy adult dogs, TPLO anesthesia is considered low-risk. The most significant risks involve cardiovascular depression from the anesthetic agents and hypothermia during the procedure.

These are managed through continuous monitoring and supportive care. Pre-anesthetic blood work identifies dogs with conditions that increase risk.

How long is the dog under anesthesia for TPLO?

Total anesthesia time typically ranges from 1.5 to 2.5 hours for a standard TPLO, depending on the surgeon's experience and any complications.

Dogs are usually extubated within 15 to 30 minutes of the end of surgery as they recover consciousness.

What happens if my dog is in pain when it wakes up from TPLO?

Post-operative pain assessment is performed by the veterinary team as the dog recovers. Rescue analgesia (additional opioid doses) is given if pain scores exceed defined thresholds.

The goal of the multimodal protocol is to prevent pain peaks rather than treat pain after it occurs.

Contact the surgical team if your dog appears to be in significant pain after discharge.

My dog is older. Is anesthesia more dangerous?

Age increases anesthetic risk because older dogs are more likely to have subclinical cardiac, renal, or hepatic disease, slower drug metabolism, and reduced physiological reserve.

Thorough pre-anesthetic bloodwork and cardiac assessment (chest X-ray, echocardiogram in selected cases) helps quantify risk. The anesthetic team adjusts protocols for older patients with reduced drug doses and enhanced monitoring.

What does fasting before TPLO mean?

Food is typically withheld for 8 to 12 hours before anesthesia to reduce the risk of vomiting and aspiration during induction or recovery.

Water restriction is typically shorter often until the night before or only 2 to 4 hours before surgery.

Follow your surgeon's specific instructions, which are tailored to your dog's size and health status.

Resources

• PMC. Postoperative Opioid-Free Analgesia in Dogs Undergoing TPLO: A Feasibility Study. pmc.ncbi.nlm.nih.gov
• PMC. Incidence of Postoperative Opioids in TPLO Dogs After Liposomal Bupivacaine With or Without Morphine Epidural. ncbi.nlm.nih.gov
• PubMed. Comparison of Perioperative Analgesic Protocols for Dogs Undergoing TPLO. pubmed.ncbi.nlm.nih.gov
• PMC. Effects of Saphenous and Sciatic Nerve Blocks, Lumbosacral Epidural or MLK CRI on Postoperative Pain in TPLO Dogs. pmc.ncbi.nlm.nih.gov
• VCA Animal Hospitals. Tibial Plateau Leveling Osteotomy (TPLO) in Dogs. vcahospitals.com

A seroma is one of the most common soft tissue complications after TPLO surgery in dogs.

Finding a soft lump under the skin near the surgical site is alarming, but in most cases it is a benign finding that resolves with strict rest and time.

Understanding the difference between a seroma and a more serious complication helps you respond appropriately.

Quick answer: A seroma is clear serum fluid under the TPLO incision, not an infection. Small seromas resolve in 1 to 3 weeks with rest; larger ones need sterile aspiration. Call your vet if the swelling is hot, fast-growing, or producing discharge.

Key takeaways

• A seroma is clear serum fluid under the skin — not an infection; a benign accumulation from disrupted blood and lymphatic vessels
• Excessive activity is the leading preventable cause: unnecessary movement produces more fluid and enlarges the seroma
• Small seromas resolve with strict rest in 1 to 3 weeks: the lymphatic system reabsorbs the fluid without intervention
• Large seromas may need needle aspiration: a sterile outpatient procedure by your vet; never drain at home
• Warm packs twice daily help reabsorption: 10 minutes of warmth twice daily is recommended for established seromas
• A seroma that becomes warm, red, painful, or produces discharge needs immediate vet attention it may have become infected

What is a seroma?

Vetinfo explains that a seroma is a swelling resulting from the accumulation of fluid under the skin.

It is made of serous fluid (blood plasma without most of the cells), so it is usually watery with a slight pink tinge rather than dark blood or cloudy infected fluid.

After TPLO surgery, the osteotomy site and surrounding soft tissues leave behind a space between tissue layers called dead space where fluid from disrupted capillaries and lymphatics can collect.

The fluid pools there before the body's healing processes close the space.

Seromas feel soft, fluctuant (squishy), and move under finger pressure. They are usually not painful when small and are not warm to the touch.

These features distinguish them from infections, which are typically warm, firm, painful, and may produce purulent discharge.

What causes seromas after TPLO?

Excessive activity

This is the most important and most preventable cause. Vetinfo confirms that seromas occur when a dog is active immediately after surgery instead of remaining inactive during recovery.

Every unnecessary step disrupts the tissue planes that need to approximate and seal, producing more fluid.

The surgeon Dr.

Matt confirms on JustAnswer that the best way to reduce seromas is to restrict activity as much as possible at least 8 weeks of restricted activity after TPLO is recommended.

Dead space at the surgical site

TPLO surgery involves significant soft tissue dissection around the proximal tibia. Closing this space with sutures reduces but does not eliminate dead space.

Any gap between tissue layers fills with fluid before normal healing closes it.

Surgical drainage

In some cases, surgical drains are placed during the procedure to allow fluid to escape rather than collect.

Not all surgeons routinely place drains some reserve them for dogs considered at higher risk of seroma formation.

Patient factors

Larger dogs produce more dead space and more fluid. Dogs with more subcutaneous fat are at higher risk.

Dogs that are particularly active during recovery despite attempts at confinement are most likely to develop significant seromas.

Recognizing a seroma

Classic signs:

• Soft, squishy swelling directly under or near the incision site
• The swelling moves under pressure it feels like a water balloon
• Normal skin color over the swelling (not red or purple)
• Not painful when gentle pressure is applied
• Not warm to the touch
• No discharge from the skin over the swelling

When to suspect infection instead:

• The swelling is warm, red, or firm rather than soft
• A draining tract or discharge appears from the skin
• The dog shows increased pain, fever, lethargy, or loss of appetite
• The swelling is growing rapidly

Treatment

Small seromas: observation and rest

Cuteness notes that most often the body absorbs the fluid and the swelling diminishes. For small seromas (typically under 3 cm), the approach is:

• Enforce strict activity restriction no running, jumping, or free roaming
• Cold compresses in the first few days (reduces new fluid production)
• Warm compresses from days 5 onward 10 minutes, twice daily to promote fluid reabsorption
• Monitor size and character daily

Large or persistent seromas: needle aspiration

Large seromas that are uncomfortable or not responding to rest may be drained by your veterinarian using a sterile needle and syringe. This is a simple outpatient procedure.

Cuteness confirms that veterinarians may drain or aspirate the seroma to make the dog more comfortable.

Aspiration provides relief but does not address the underlying dead space. The seroma may refill sometimes multiple aspirations are required. After aspiration, continued strict rest is essential.

Compression bandaging

A gentle compression bandage applied by your vet reduces dead space and discourages fluid refilling after aspiration.

Improper bandaging can cause pressure sores or circulatory compromise, so bandages must be applied and monitored by a veterinarian.

Surgical drain placement

If a seroma repeatedly refills after aspiration, a closed suction drain may be placed to allow ongoing drainage until the dead space closes.

This is uncommon but is an option for persistent or large seromas.

For the full fluid buildup guide covering all types of post-TPLO fluid accumulation, see fluid buildup after TPLO surgery in dogs.

For incision complications including infection, see TPLO incision infection symptoms and prevention. For the full complications reference, see 15 common complications after TPLO surgery in dogs.

For the incision redness guide to distinguish seroma from infection, see redness after TPLO surgery in dogs: causes and care.

Frequently asked questions

Can a seroma go away on its own?

Yes in the majority of cases, small seromas resolve without intervention as the body reabsorbs the fluid over 1 to 3 weeks.

Strict activity restriction is essential; without it, the seroma will continue to refill as fast as it drains.

Do not assume a seroma will resolve if the dog is not being properly confined.

Should I drain the seroma myself at home?

Never. Home drainage risks introducing bacteria into a sterile fluid collection, converting a benign seroma into an infected abscess. Only a veterinarian should aspirate a seroma under sterile conditions.

If you believe the seroma needs draining, contact your vet.

My dog's seroma looks like it ruptured through the skin. What do I do?

Spontaneous seroma rupture does occasionally occur. The fluid drains through the skin, leaving a small wound.

Contact your vet immediately for guidance the wound will need to be kept clean and monitored for infection. A veterinarian Dr.

Matt reports this occurrence on JustAnswer, confirming prompt vet contact is appropriate.

How long does a seroma last after TPLO?

Small seromas typically resolve in 1 to 3 weeks with strict activity restriction. Larger ones may take 4 to 6 weeks and may require aspiration.

If a seroma persists beyond 4 weeks without improvement, a veterinary recheck is warranted.

Is a seroma the same as an infection?

No. A seroma is sterile fluid no bacteria. An infection involves bacterial colonization and produces different characteristics: warmth, redness, purulent discharge, systemic illness signs.

Bacterial culture distinguishes them definitively if clinical assessment is uncertain.

Resources

• Vetinfo. Seroma After-Surgery Care for Dogs. vetinfo.com
• Cuteness. What Are the Treatments for Seroma Formation in Dogs? cuteness.com
• VCA Animal Hospitals. Seroma in Dogs. vcahospitals.com
• TPLO Info. Recovery FAQs. tploinfo.com

CCL (cranial cruciate ligament) rupture is one of the most common orthopedic injuries in dogs.

Canine CCL rupture often develops gradually through progressive degeneration. Early signs are subtle and easy to dismiss as aging or a minor sprain.

Recognizing the signs early improves outcomes because partial tears can progress to complete ruptures if not addressed.

Quick answer: Common signs a dog may need TPLO surgery: persistent rear limb limping, stiffness after rest, toe-touching gait, sitting with one rear leg extended (positive sit test), stifle swelling and warmth, and sudden non-weight bearing. A drawer test and radiographs confirm CCL rupture.

Key takeaways

• Hind limb lameness is the most common presenting sign: any dog with a persistent rear leg limp warrants veterinary evaluation; CCL rupture is the most common orthopedic cause
• The classic sitting posture change is highly specific: a dog now sitting with one rear leg extended to the side rather than tucked under is compensating for stifle pain (positive sit test)
• Intermittent lameness that comes and goes may indicate a partial tear: partial tears progress to complete ruptures in most dogs without treatment
• Stiffness after rest or sleep is a common early sign: the dog seems fine after moving around but is stiff when first rising
• Non-weight bearing or acute severe lameness after activity indicates a complete CCL rupture; the dog holds the leg entirely off the ground
• Both stifles are at risk: 30 to 40% of dogs develop CCL rupture in both knees over time; monitor the opposite side in any dog with known CCL disease

The 13 signs

1. Hind limb limping after exercise

The dog walks normally at rest but limps noticeably after running, playing, or climbing stairs. The limping may resolve after 10 to 30 minutes of rest.

This pattern suggests the joint can handle low-level loading but is symptomatic under increased mechanical stress.

SustainableVet.org confirms: occasional limping may come and go, especially after exercise or long walks; some days may seem better than others, but this inconsistency is a sign of joint problems.

2. Toe-touching gait (barely bearing weight)

The dog walks with most weight on three legs, barely resting the toes of the affected rear limb on the ground.

The toe touches down for stability and ground contact but carries almost no weight.

SustainableVet.org confirms: the dog may lightly place just the toes of the affected leg on the ground without putting full weight on it; this is a common sign of knee pain.

Coldwater Online confirms: sitting with the leg kicked out to the side is a classic signal.

3. Sitting with one rear leg extended to the side (positive sit test)

A dog with stifle pain cannot comfortably flex the knee to a normal sitting position. Instead, the affected leg extends out to the side while the dog sits.

This is reproducible and highly suggestive of stifle pathology.

AESC confirms: dogs with CCL tears often sit with one leg stuck out to the side rather than tucked normally.

4. Stiffness after rest or sleep

The dog gets up from sleeping or lying and is noticeably stiff and lame for the first few minutes. After moving around, the stiffness resolves.

This is the classic pattern of joint inflammation: fluid redistribution during rest causes stiffness that is mobilized by movement.

Coldwater Online confirms: stiffness after rest, especially in the morning or after a nap, is a classic early signal.

5. Reluctance to go up or down stairs

Climbing stairs requires repetitive stifle flexion and load bearing. A dog with a partial or complete CCL tear shows hesitation or refusal to use stairs, often pausing at the base or top.

6. Reluctance to jump into the car or onto furniture

Loading into the car from the ground requires a pushing-off motion from the rear legs with sudden stifle extension. Dogs with CCL pain become reluctant to perform this movement.

7. Muscle atrophy of the rear leg

The quadriceps and hamstring muscles of the affected leg visibly reduce in size compared to the opposite leg. This occurs because the dog guards the painful limb and reduces loading over time.

Noticeable asymmetry in thigh circumference is a sign of chronic or progressive CCL disease.

8. Swelling at the stifle joint

The stifle (knee) joint becomes palpably enlarged.

The medial compartment (inside of the knee) often shows a visible soft tissue swelling called a medial buttress -- fibrous tissue that develops in response to chronic joint instability.

The joint may feel warm compared to the opposite stifle.

MetLife Pet Insurance confirms: the stifle area may appear swollen or feel warm to the touch.

9. Audible popping or clicking from the knee

Meniscal damage accompanies CCL rupture in approximately 40 to 60% of chronic cases.

When the unstable tibia slides across the femoral condyles, it may crush or tear the meniscus, producing an audible clicking or popping sound.

AESC confirms: popping noises as the knee joint moves may be heard and are a sign of possible meniscal involvement.

10. Sudden complete non-weight bearing after activity

The dog was running, playing, or jumping, then suddenly cried out and completely stopped using the rear leg. This acute presentation indicates a sudden complete CCL rupture.

Unlike gradual partial tears, complete acute ruptures are painful and dramatic at onset.

Sandringham Vet confirms: most dogs with a CCL tear will avoid putting weight on the affected leg; difficulty standing up or sitting from a resting position is common after complete rupture.

11. Chronic intermittent lameness with improvement then worsening

The dog limps, seems to improve, then worsens again. This cyclical pattern often reflects a partial tear progressing with activity then settling with rest.

Without treatment, partial tears progress to complete ruptures in most dogs.

12. Both rear legs showing signs simultaneously

Some dogs present with bilateral CCL disease -- both stifles partially or completely ruptured.

These dogs show a characteristic bunny-hopping gait (using both rear legs together rather than alternating) or severe difficulty rising.

Midvalley Animal Clinic notes 30 to 40% of patients will develop CCL rupture in both knees over time.

13. Hindquarters weakness or instability during activity

The dog's rear end seems weak or gives way during turning, running, or on uneven terrain. This reflects dynamic instability of the stifle under load rather than pain at rest.

How the diagnosis is confirmed

Signs alone are not sufficient for definitive diagnosis. Veterinary confirmation requires:

Physical examination tests

Tibial thrust test: the vet applies cranial-directed force to the hock while stabilizing the femur. In a CCL-deficient stifle, the tibia slides forward under this force.

Drawer test: with the dog sedated or relaxed, the vet grasps the femur and tibia and attempts to slide them in opposite directions. Forward movement of the tibia relative to the femur (cranial drawer) confirms CCL rupture.

Chewy confirms: your veterinarian will check for tibial thrust -- abnormal sliding of femur and tibia. A positive drawer test confirms CCL rupture is very likely.

Radiographs

X-rays assess joint fluid accumulation (which causes fat pad displacement on the lateral view -- the "fat pad sign"), early arthritis changes, and tibial plateau angle (TPA) measurement for surgical planning.

Radiographs do not directly image the CCL but confirm the secondary changes of CCL disease.

Arthroscopy or arthrotomy

At the time of surgery, the surgeon directly inspects the CCL and menisci. This provides the definitive diagnosis and allows concurrent meniscal treatment.

For the TPLO surgery overview, see what causes TPLO surgery to be needed in dogs. For alternatives, see alternatives to TPLO surgery for dogs.

For TPLO vs lateral suture, see lateral suture vs TPLO for dogs. For surgery preparation, see preparing for your dog's TPLO surgery.

Frequently asked questions

Can a dog with a CCL tear recover without surgery?

Partial tears in very small dogs (under 10 to 15 kg) sometimes stabilize with strict rest and conservative management.

For most dogs, particularly those over 15 to 20 kg, conservative management does not restore normal joint stability and the lameness persists or worsens.

Complete ruptures in any dog over about 15 kg typically require surgery for full functional recovery.

How quickly does a CCL tear progress if untreated?

A partial tear typically progresses to a complete rupture within weeks to months if activity is not restricted. Arthritis develops progressively from the moment the joint becomes unstable.

Early treatment reduces arthritis progression and improves long-term outcomes.

My dog limped once and then seemed fine. Should I go to the vet?

Yes, if the limp was in a rear leg and involved guarding or reduced weight bearing. A single episode of rear limb lameness lasting more than a few minutes warrants evaluation.

Early CCL tears can produce episodic lameness that resolves with rest -- evaluation while the dog appears normal can still reveal joint instability or effusion on examination.

Does the dog need sedation for the drawer test?

Sedation often improves accuracy. A dog in pain or a large, tense dog may resist examination sufficiently to produce a false-negative drawer test.

Sedation allows full relaxation and more reliable assessment of drawer and tibial thrust.

Which breeds are most at risk for CCL rupture?

Dispomed confirms high-risk breeds include Rottweilers, Newfoundlands, Staffordshire Terriers, Mastiffs, Akitas, Saint Bernards, Labrador Retrievers, and Chesapeake Bay Retrievers. Neutered dogs are at higher risk than intact dogs of the same breed.

Obesity and poor physical condition also increase risk.

Resources

• SustainableVet. 13 Signs Your Dog May Need TPLO Surgery. sustainablevet.org
• AESC Parker. TPLO Surgery in Dogs: Frequently Asked Questions. aescparker.com
• MetLife Pet Insurance. TPLO Surgery for Dogs. metlifepetinsurance.com
• ACVS. Cranial Cruciate Ligament Disease. acvs.org

A meniscal tear after TPLO surgery is one of the most recognized post-operative complications.

The medial meniscus is at risk both at the time of CCL rupture and after surgery, when residual instability or degenerative changes can damage tissue that appeared normal during the original procedure.

Recognizing the signs early significantly improves outcomes.

Quick answer: Post-TPLO meniscal tears present as sudden lameness return in a previously improving dog, often with a meniscal click. Late tears occur in 2 to 22% of TPLO cases (RCVS). PubMed found 5.6% late meniscal tear incidence. Treatment is partial meniscectomy; all dogs treated returned to peak limb function per PubMed.

Key takeaways

• Late meniscal tears occur in 2 to 22% of post-TPLO dogs: RCVS confirms this range; a PubMed TPLO arthroscopy study found a 5.6% late meniscal tear incidence
• The hallmark sign is sudden lameness regression in a previously improving dog: RCVS confirms affected dogs display good mobility and then go suddenly lame; this trajectory reversal distinguishes meniscal injury
• The meniscal click is audible but not always present: the absence of a click does not rule out meniscal injury
• The meniscus does not heal on its own: limited blood supply prevents natural regeneration; small tears may be managed conservatively but most require partial meniscectomy
• Partial meniscectomy produces excellent outcomes: all dogs treated by partial meniscectomy returned to peak limb function (PubMed); outcomes at 6 months are comparable to dogs with intact menisci
• Concurrent meniscal tears do not worsen long-term outcomes: AVMA research found similar midterm outcomes for TPLO plus meniscectomy vs TPLO alone, despite more severe arthritis at surgery

The medial meniscus: what it is and why it is at risk

The medial meniscus is a crescent-shaped fibrocartilage structure on the inner surface of the stifle joint. It distributes joint load, provides shock absorption, and stabilizes the joint during weight bearing.

Each stifle has two menisci. The medial is injured far more frequently because it is firmly attached to the tibia and cannot shift away from the abnormal tibial movement during CCL rupture.

SustainableVet.org confirms: the medial meniscus is more prone to injury because it is firmly attached to the tibia. When the tibia slides forward, it is compressed by the femoral condyle.

Why meniscal tears occur after TPLO

Latent tears missed at surgery

At the time of TPLO, the surgeon examines the meniscus through a small arthrotomy or arthroscopy and removes any clearly damaged tissue. However, not all tears are visible at surgery.

Small partial-thickness tears or areas of early degeneration may not be identifiable intraoperatively but progress to complete tears in the weeks or months after surgery.

PMC confirms: post-surgical meniscal pathology may be due to failure of diagnosis at the time of surgery (latent tears) or a result of residual joint instability (post-liminary tears).

Residual joint instability after TPLO

TPLO eliminates the cranial shear force that destabilized the joint. However, the stifle undergoes significant remodeling in the weeks after surgery, and some residual instability may persist during this period.

This can subject a structurally weakened meniscus to loading forces that produce tearing.

SustainableVet.org confirms: meniscal tears after TPLO can occur due to ongoing joint instability before surgery, direct trauma, or degenerative changes.

Progressive degeneration

Older dogs are at higher risk for meniscal tears because the meniscus undergoes age-related degeneration -- loss of collagen fiber organization, reduced cell density, and decreased water content.

PMC confirms: increasing age is a risk factor for medial meniscal tear; the meniscus experiences oxidative stress and abnormal matrix organization that can lead to injury under normal loading forces.

Concurrent vs. late meniscal tears

Concurrent (primary) tears

These are meniscal tears present at the time of TPLO and treated during the original surgery. PubMed data found a concurrent meniscal tear prevalence of 32.2% in dogs undergoing TPLO.

These are removed at the time of the procedure via arthrotomy or arthroscopy.

Late (secondary) tears

These are meniscal tears that develop after TPLO in a previously intact or adequately treated meniscus. The PubMed TPLO arthroscopy study found a late meniscal tear incidence of 5.6%.

RCVS Canine Cruciate Registry confirms late meniscal tears are seen in 2 to 22% of cases.

SustainableVet.org confirms: a secondary meniscus tear often happens weeks or months after the initial procedure and results in immediate pain, limping, and reluctance to move.

Symptoms of a post-TPLO meniscal tear

Sudden lameness regression: the most characteristic sign. A dog making steady progress suddenly becomes lame on the operated leg. This is distinct from the gradual variability of normal TPLO recovery.

Audible or palpable meniscal click: a clicking or popping sound during stifle flexion and extension. SustainableVet.org confirms the knee may produce a clicking sound when moving. The click is heard when the torn meniscal flap is displaced by the femoral condyle.

Pain on stifle manipulation: the dog flinches, vocalizes, or resists when the stifle is flexed through its range. This distinguishes pain from benign mechanical clicking.

Stifle swelling: joint effusion may increase from the baseline level. The joint feels fuller and may be warmer than the contralateral stifle.

Reluctance to bear weight: the dog shifts weight off the operated leg, holds the leg up, or toe-touches only.

SustainableVet.org confirms: 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.

Diagnosis

Veterinary evaluation includes:

Physical examination: stifle manipulation to assess pain, range of motion, joint effusion, and presence of a palpable meniscal click. The McMurray-type maneuver and medial meniscal compression test are used to localize meniscal pain.

Radiographs: assess joint effusion (fat pad displacement), osteotomy healing, and implant position. Radiographs do not directly image the meniscus but rule out implant complications as the cause of lameness.

Arthroscopy or arthrotomy: definitive diagnosis. Direct visualization of the meniscus under anesthesia identifies the location, type, and severity of the tear.

Treatment

Conservative management

Small or partial-thickness tears without significant clinical signs can be managed conservatively with:

• NSAIDs for 4 to 8 weeks
• Strict activity restriction
• Joint supplements (omega-3 fatty acids, glucosamine, chondroitin)
• Reassessment if signs do not resolve

SustainableVet.org confirms: small tears may be managed with rest, NSAIDs, and joint supplements; but severe cases often require surgical intervention.

Partial meniscectomy

The definitive treatment for complete or symptomatic meniscal tears. The surgeon removes the damaged portion of the meniscus arthroscopically or via a small arthrotomy, leaving the undamaged portion intact.

The outcomes of partial meniscectomy are excellent. PubMed confirms: all dogs with late meniscal tears treated by partial meniscectomy returned to peak postoperative limb function based on client-assessed outcomes.

AVMA research confirms: treatment for meniscal tear results in significant improvement in lameness, with postoperative outcomes at 6 months comparable to dogs with intact menisci.

RCVS confirms: meniscal tears are treated by removing the torn portion. Dogs with long-term meniscal tears have a bit more osteoarthritis but generally maintain a good quality of life.

Post-meniscectomy recovery

Recovery after partial meniscectomy is typically faster than the original TPLO recovery. The osteotomy is already healed; the additional recovery is for the joint to settle after the meniscectomy.

Most dogs return to normal activity within 4 to 8 weeks.

For the clicking guide, see why is my dog's leg clicking after TPLO surgery?. For the lameness guide, see lameness after TPLO surgery in dogs.

For the infection signs guide, see earliest signs of TPLO infection. For the TPLO complications guide, see 15 common complications after TPLO surgery.

Frequently asked questions

How do I know if it is a meniscal tear or normal recovery variability?

The key is trajectory. Normal recovery shows week-over-week improvement with occasional minor setbacks. A meniscal tear produces a clear regression: the dog was improving, then suddenly lame.

If your dog has been consistently improving and then becomes acutely lame, contact your vet the same day.

Can a meniscal tear be seen on X-ray?

No. Radiographs cannot image cartilage. X-rays assess bone, implant, and joint effusion. A suspected meniscal tear requires arthroscopy or an MRI (less common in veterinary practice) for definitive diagnosis.

Will my dog need another general anesthetic for the meniscectomy?

Yes. Arthroscopy or arthrotomy for partial meniscectomy requires general anesthesia. The procedure is typically shorter than the original TPLO and recovery is faster because the plate and osteotomy are already healed.

Is there anything that could have been done to prevent this?

Not reliably. The risk of late meniscal tears is partly structural (inherent joint instability during healing), partly degenerative (pre-existing meniscal weakness), and partly age-related.

Strict activity restriction during recovery reduces the risk by minimizing the abnormal joint loading that can damage a weakened meniscus, but it cannot eliminate risk entirely.

My dog had a concurrent meniscal tear treated at the time of TPLO. Is the outcome worse?

No.

AVMA research confirms similar midterm functional outcomes for TPLO plus meniscectomy vs TPLO alone in dogs with intact menisci.

Resources

• RCVS Canine Cruciate Registry. Meniscal Tears. ccr.rcvsknowledge.org
• PubMed. Incidence of Medial Meniscal Tears After Arthroscopic Assisted TPLO. pubmed.ncbi.nlm.nih.gov
• AVMA Journals. Concurrent Bucket Handle Meniscal Tear Treated with Arthroscopic Partial Meniscectomy Does Not Influence Midterm Outcomes After TPLO. avmajournals.avma.org
• PMC. Associations Between Meniscal Tears and Osteoarthritis Among Dogs Undergoing TPLO. pmc.ncbi.nlm.nih.gov

TPLO surgery tibial plateau leveling osteotomy is the most commonly recommended surgical treatment for cranial cruciate ligament (CCL) rupture in dogs in the United States.

For the right dog, it reliably restores function. For some dogs, the cost, recovery demands, and surgical risks may outweigh the benefits.

Understanding both sides helps you make an informed decision with your veterinarian.

Quick answer: TPLO surgery achieves 93% functional success and durable mechanical stability. Cons include $3,000 to $6,000+ cost per leg, 10 to 16 weeks of strict recovery, a 14 to 34% complication rate, and a 30 to 50% chance the other knee eventually ruptures.

Key takeaways

• 93% of dogs regain good limb function after TPLO, based on a 2013 clinical outcomes study
• TPLO is the gold standard for medium-to-large breed dogs: ACVS recommends it as first choice for CCL rupture in dogs over 60 lbs
• Overall complication rate is 14 to 34%: fewer than 10% of cases require a second surgery
• Infection occurs in approximately 6% of cases and is the most common serious post-TPLO complication
• Recovery takes 10 to 16 weeks of strict rest, the most demanding aspect of TPLO for most families
• Cost ranges from $3,000 to $6,000+ per leg one of the most significant disadvantages for many dog owners

What is TPLO surgery?

TPLO surgery addresses CCL rupture by changing the mechanics of the stifle (knee) joint rather than replacing the torn ligament.

The surgeon makes a curved cut in the top of the tibia and rotates the bone segment to flatten the tibial plateau angle, typically to around 5 degrees.

This eliminates the forward sliding force that the CCL normally resists, allowing the dog to bear weight without a functioning ligament.

According to the American College of Veterinary Surgeons (ACVS), TPLO is currently the most commonly recommended procedure for CCL rupture in large and active dogs.

To understand the full surgical process, see what is TPLO surgery in dogs.

Pros of TPLO surgery

High success rate

A 2013 clinical study published in veterinary literature found that TPLO patients achieved a 93% restoration of limb function at one year post-surgery.

This is consistently among the highest success rates of any CCL repair technique.

Vetamac reports that TPLO has higher success rates and lower complication rates compared to extracapsular repair (lateral suture) in medium and large breed dogs.

Most dogs return to running, playing, and normal daily activity with minimal long-term limitations.

Durable mechanical stability

TPLO works by fundamentally changing joint mechanics not by substituting a suture for the torn ligament.

This means the stability it provides does not depend on the integrity of a synthetic material that can loosen over time.

Extracapsular repair relies on periarticular fibrosis to maintain long-term stability after the suture eventually loosens.

TPLO does not have this limitation, making it more reliable in active dogs where joint forces are higher.

Slower arthritis progression

Osteoarthritis will develop in any stifle affected by CCL disease, regardless of treatment.

However, restoring joint stability through TPLO slows the rate of cartilage loss and reduces the severity of arthritis compared to untreated or inadequately stabilized joints.

VCA Animal Hospitals notes that TPLO offers better long-term stability and faster recovery than conservative management.

This makes it the preferred choice for many veterinarians treating CCL injuries in active dogs.

Earlier return to function

Dogs typically begin bearing weight within days of TPLO surgery. Most are walking on the operated leg within the first week and show progressive improvement through weeks 6 to 12.

This earlier functional return benefits active working dogs and reduces muscle atrophy during recovery.

Cons of TPLO surgery

High cost

TPLO surgery costs $3,000 to $6,000 per leg at specialist centres in the US, and higher in major metropolitan areas. Bilateral cases (both knees) can reach $8,000 to $12,000 total.

Additional costs include preoperative diagnostics, post-operative pain medication, follow-up radiographs, and rehabilitation therapy. This is one of the most significant barriers for many families.

Long, demanding recovery

Recovery after TPLO requires 10 to 16 weeks of strict activity restriction. Dogs must be confined, leashed at all times outdoors, and prevented from running, jumping, or using stairs.

For active dogs and their owners this is one of the hardest aspects of TPLO.

The bone takes at least eight weeks to heal. Premature activity is one of the leading causes of post-surgical complications and implant failure.

See 10 essential TPLO recovery tips for pet owners for the full recovery guide.

Complication risk

Vetamac reports that complication rates following TPLO surgery range from 14 to 34%, with fewer than 10% requiring a second surgery. The most frequent complications include:

• Surgical site infection: approximately 6% of cases
• Implant loosening or failure: less common but can require plate removal
• Late meniscal tear: occurs in 2 to 4% of cases after surgery
• Seroma or hematoma: fluid accumulation under the incision
• Tibial crest fracture: rare but serious

For the complete list, see 15 common complications after TPLO surgery in dogs. For the overall failure rate, see TPLO failure rate in dogs explained.

Not appropriate for all dogs

TPLO is not the best option for every dog. Very small dogs (under 15 to 20 lbs) often achieve equivalent outcomes with extracapsular repair at significantly lower cost and complexity.

Dogs with serious concurrent medical conditions significant cardiac, renal, or hepatic disease may be higher anesthetic risks than the procedure warrants.

Most surgeons consider TPLO the optimal choice for young, active, large-breed dogs. For older dogs, the decision involves more nuance. See TPLO surgery for older dogs for the full discussion.

30 to 50% risk of the other knee rupturing

One of the most important facts owners often learn after surgery: 30 to 50% of dogs that rupture one CCL will eventually rupture the other.

This is not a failure of TPLO both ligaments degenerate simultaneously. However, it means many families face a second surgery within 1 to 2 years.

TPLO pros and cons: summary table

For the full comparison of surgical alternatives, see alternatives to TPLO surgery for dogs. For long-term outcomes data, see long-term outcomes of TPLO surgery.

Frequently asked questions

Is TPLO surgery worth the cost?

For active, medium-to-large breed dogs with complete CCL rupture, the evidence strongly supports TPLO as worth the investment.

A 93% functional success rate and durable mechanical stability justify the cost for most families. For very small or elderly dogs, alternatives may offer equivalent outcomes at lower cost and surgical risk.

What is the biggest downside of TPLO surgery?

Most owners cite the 10 to 16 week activity restriction as the hardest part more challenging in practice than anticipated. Cost is the second most common concern.

From a medical standpoint, the 14 to 34% complication rate is the main clinical disadvantage, though most complications are manageable without a second surgery.

Can a dog live a normal life after TPLO?

Yes. The ACVS notes that the majority of dogs return to full activity including running and playing.

Long-term management may include joint supplements, weight management, and monitoring for arthritis but the vast majority of dogs live active, comfortable lives after successful TPLO recovery.

How does TPLO compare to extracapsular repair?

TPLO has higher success rates in medium and large breed dogs and provides more reliable long-term stability.

Extracapsular repair (lateral suture) is less expensive and less invasive but is generally not recommended for dogs over 30 lbs due to higher long-term failure rates in larger, more active patients.

What happens if TPLO surgery is not done?

Without surgical stabilization, CCL rupture causes progressive joint instability, ongoing meniscal damage, pain, and rapid osteoarthritis progression. In large dogs, conservative management produces significantly worse long-term outcomes than surgery.

Small dogs under 15 lbs sometimes achieve acceptable function without surgery, but even in them, surgery typically produces better results.

Resources

• ACVS. Cranial Cruciate Ligament Disease. acvs.org
• Vetamac. TPLO Surgery for Dogs: Success Rates and Alternative Options. vetamac.com
• Animal Outpatient Surgery. Is TPLO Surgery Worth It? animaloutpatientsurgery.com
• VCA Animal Hospitals. Tibial Plateau Leveling Osteotomy (TPLO) in Dogs. vcahospitals.com