TPLO has a high overall success rate, but complications do occur. The published overall complication rate ranges from 10 to 34%, with most complications being minor and manageable.
Knowing what to watch for -- and when a sign requires a same-day call vs. a mention at the next scheduled appointment -- allows owners to respond appropriately.
Quick answer: The 15 most common post-TPLO complications: surgical site infection, seroma, implant loosening or failure, osteomyelitis, late meniscal tear, tibial tuberosity fracture, delayed bone healing, persistent lameness, non-union, intra-articular screw placement, nerve damage, patellar tendon thickening, patellar luxation, progressive osteoarthritis, and contralateral CCL rupture. Most are minor and manageable.
Key takeaways
- The overall complication rate is 10 to 34%: most complications are minor (swelling, mild infection); serious complications such as implant failure or osteomyelitis are less common
- SSI is the most frequent single complication: reported in 2.9% to 17.3% of TPLO procedures; most are superficial and treatable with antibiotics if caught early
- Late meniscal tear occurs in 1.8% to 10.5% of cases where the meniscus was normal at surgery; it presents as sudden lameness return with meniscal click
- Tibial tuberosity fracture is reported in 1 to 9% of TPLO cases: incorrect positioning and oversized saw blades are the main risk factors
- Implant-associated infection occurred in 3.4% and osteomyelitis in 0.6% across numerous studies; osteomyelitis requires strong antibiotics for 4 to 6 months and sometimes plate removal
- Contralateral CCL rupture is a significant long-term risk: 30 to 40% of dogs develop rupture of the opposite CCL; owners should monitor the opposite stifle
Early complications (weeks 0 to 8)
1. Surgical site infection (SSI)
The most common complication. SSI ranges from superficial incisional infection (treatable with oral antibiotics and wound care) to deep implant-associated infection requiring plate removal.
Signs: redness spreading beyond the incision, warmth, swelling, cloudy or malodorous discharge.
Incidence: 2.9% to 17.3% per published literature; the PMC 769-TPLO study (769 procedures) found 8.5%.
Management: culture-directed antibiotics for superficial infections; surgical debridement and sometimes plate removal for deep implant infections.
2. Seroma
A localized collection of clear serous fluid under the skin near the incision, typically appearing 1 to 3 weeks post-surgery.
Signs: soft, fluctuant swelling at or near the incision; no warmth or redness; clear fluid if aspirated.
Incidence: common; most resolve without treatment.
Management: monitoring; aspiration if large or causing discomfort; bandaging in some cases.
3. Acute lameness from overactivity
The dog is over-active during the restriction period and bears too much load on the plate before the osteotomy heals.
Signs: sudden worsening of lameness after a period of improvement; may indicate implant stress or early failure.
Management: strict crate rest; radiographic assessment to rule out implant displacement.
4. Wound dehiscence
The incision edges separate before fully healing. More common in dogs that lick the incision despite an e-collar that fits incorrectly.
Signs: open wound edges, sometimes with tissue visible.
Management: cleaning and re-closure in most cases; e-collar compliance review.
Mid-term complications (weeks 4 to 16)
5. Delayed bone healing
The osteotomy is not showing expected consolidation on radiographs at the 6 to 8 week checkpoint.
Signs: radiographic evidence of widening osteotomy gap or absence of callus formation; may or may not produce clinical signs.
Risk factors: infection, excessive activity, poor bone quality (older dogs, large breeds), NSAIDs at high doses for extended periods.
Management: extended activity restriction; investigate for underlying infection; nutritional support.
6. Tibial tuberosity fracture
A fracture of the tibial tuberosity (the prominence where the patellar tendon attaches) caused by the osteotomy saw blade coming too close to this structure.
Incidence: 1 to 9% per Laguna Woods Vets; higher in dogs with high TPA, high body weight, and large TPA change.
Signs: acute severe lameness; radiographic evidence of fracture.
Management: surgical repair or conservative management depending on displacement.
7. Late meniscal tear
A meniscal tear occurring after TPLO in a meniscus that appeared normal at surgery. See the dedicated meniscal tear article for full detail.
Incidence: 1.8% to 10.5% of cases with normal meniscus at TPLO (Dog Discoveries).
Signs: sudden lameness regression; meniscal click on movement; pain on stifle manipulation.
Management: partial meniscectomy.
8. Implant loosening or failure
The plate or screws shift, bend, or break -- typically from premature overactivity before the osteotomy heals.
Signs: sudden severe lameness; pain at plate site; radiographic evidence of screw loosening, plate migration, or osteotomy displacement.
Management: revision surgery in most cases of significant displacement.
Long-term complications (months 3 and beyond)
9. Osteomyelitis
Bone infection extending from a superficial SSI or introduced via hematogenous seeding. Difficult to treat.
Incidence: 0.6% per Dog Discoveries citing multiple studies.
Signs: persistent lameness; draining tract; radiographic bone destruction, periosteal reaction, or sequestrum.
Management: Laguna Woods Vets confirms osteomyelitis requires strong antibiotics for 4 to 6 months; a wound culture aids antibiotic selection; plate removal is often required.
10. Non-union
The osteotomy fails to heal, resulting in permanent instability at the cut site.
Risk factors: infection, inadequate fixation, excessive motion, poor blood supply.
Signs: persistent lameness; radiographic evidence of osteotomy gap persisting beyond 16 weeks with no bridging callus.
Management: revision surgery, bone grafting, and often implant revision.
11. Intra-articular screw placement
A screw tip violates the joint space, causing joint damage and persistent pain. Best identified on the postoperative radiograph.
Signs: ongoing lameness; pain on stifle range of motion; radiographic evidence of screw in joint space.
Management: removal of the offending screw.
12. Persistent lameness without identifiable cause
Some dogs have persistent mild lameness despite uncomplicated bone healing and no identifiable complication. This may reflect residual arthritis progression, muscle atrophy, or subclinical meniscal issues.
Management: rehabilitation, joint supplements, and management of secondary osteoarthritis.
13. Patellar tendon thickening
Fibrous thickening of the patellar tendon develops in some TPLO dogs over time. This is typically not clinically significant.
Signs: palpable thickening of the patellar tendon on examination; usually incidental finding.
Management: generally none required; physiotherapy in some cases.
14. Patellar luxation
Medial patellar luxation can develop or worsen after TPLO, particularly if the plate is contoured in a way that affects patellar tracking.
Signs: intermittent lameness, popping of the patella medially on examination.
Management: surgical correction (trochleoplasty and tibial crest transposition) in symptomatic cases.
15. Progressive osteoarthritis
All dogs with CCL disease develop some arthritis progression regardless of surgical technique. TPLO slows but does not stop this process.
Signs: gradual stiffness, lameness that is worse after rest, reduced activity tolerance.
Management: joint supplements (omega-3 fatty acids, glucosamine), weight management, NSAIDs for flares, hydrotherapy.
Contralateral CCL rupture: a special consideration
Contralateral CCL rupture is not a complication of TPLO but deserves mention.
Midvalley Animal Clinic confirms it is very common (30 to 40% of patients) for both knees to develop this ligament injury.
Owners of dogs that have had unilateral TPLO should monitor the opposite stifle for early signs.
For the infection guide, see TPLO plate infection signs and treatment. For the meniscal tear guide, see dog meniscus tear after TPLO surgery.
For the failure rate overview, see TPLO failure rate in dogs. For the implant failure signs, see TPLO implant failure signs and causes.
Frequently asked questions
What is the most common serious complication after TPLO?
Deep implant-associated infection requiring plate removal is the most common serious complication, with an implant removal rate of 3.5 to 7.5% of procedures (ResearchGate).
Osteomyelitis (0.6%) and tibial tuberosity fracture (1 to 9%) are other serious but less common complications.
Is a 10 to 34% complication rate high for an orthopedic surgery?
The range is real but the majority of complications are minor -- a seroma, mild superficial infection treated with antibiotics, or a brief period of increased lameness.
Serious complications requiring revision surgery are significantly less common. TPLO's overall success rate (93% limb function restoration at 1 year per a 2013 study) reflects that most dogs recover well.
Can complications be prevented?
Most can be reduced in risk but not eliminated.
Owner-controlled risk reduction: e-collar compliance, strict activity restriction for 8 to 12 weeks, daily incision inspection, and attending all scheduled vet appointments.
What happens if my dog develops two complications simultaneously?
This is uncommon but does occur (for example, SSI leading to delayed bone healing). Management is coordinated by your surgical team based on the severity and interaction of the complications.
Contact your vet immediately for any concern.
Should I be worried every time my dog limps?
A degree of lameness is expected throughout the recovery period. The key signal is trajectory: steadily improving lameness is expected; suddenly worsening or reversed lameness is not.
Monitor for any sudden changes and contact your vet for trajectory reversals.
Resources
- PMC. Surgical Site Infection After 769 TPLOs. pmc.ncbi.nlm.nih.gov
- Laguna Woods Vets. TPLO Surgery Complications. lhah.com
- Dog Discoveries. TPLO Failure and Complications in Dogs. dogdiscoveries.com
- Clinician's Brief. Common Tibial Plateau-Leveling Osteotomy Complications. cliniciansbrief.com