Knee Replacement Regret Rate: What the Numbers Reveal

Knee replacement surgery is a surgical procedure that replaces a damaged knee joint with a prosthetic knee implant to relieve pain and restore function. While most patients report relief, a small but meaningful proportion experience post‑operative regret. Understanding the knee replacement regret rate helps surgeons set realistic expectations and equips patients to make informed choices.

Why Regret Matters in Knee Replacement

Regret isn’t just an emotional footnote; it signals unmet expectations, complications, or a mismatch between a patient’s lifestyle and the surgery’s outcomes. Researchers use regret as a safety and quality metric because it directly ties to long‑term satisfaction and the likelihood of seeking revision surgery.

How Regret Is Measured

Most studies rely on the Decision Regret Scale (DRS), a five‑item questionnaire that scores from 0 (no regret) to 100 (high regret). Patients answer statements like “I would make the same decision again” on a Likert scale. Scores above 25 are generally classified as clinically significant regret.

Reported Regret Rates Across Populations

Data from national joint registries and longitudinal cohort studies paint a consistent picture:

• Australia’s Australian Orthopaedic Association National Joint Replacement Registry (AOA NJRR) reported a 2.1% regret rate at 2‑year follow‑up for primary total knee arthroplasty (TKA).
• The US American Academy of Orthopaedic Surgeons (AAOS) pooled analysis found a 3.4% regret rate at five years, rising to 5.6% in patients over 75.
• European registries (Sweden, Norway) show regret between 1.8% and 2.9% at ten years, with higher rates linked to early complications.

In plain terms, roughly 2‑4 out of every 100 knee replacement patients feel they would have chosen a different path.

Key Drivers Behind Regret

Regret rarely stems from a single factor. The most common contributors, based on multi‑center studies, include:

1. Unrealistic pre‑operative expectations: Patients expecting to run marathons often feel let down even if pain is eliminated.
2. Post‑operative complications: Infection, stiffness, or persistent pain push regret scores above the 25‑point threshold.
3. Age and comorbidities: Older adults and those with diabetes or obesity report higher regret, partly due to slower rehab.
4. Surgeon experience and hospital volume: High‑volume surgeons (≥50 TKAs/year) consistently achieve lower regret rates-about 1.5% versus 4.2% for low‑volume providers.
5. Rehabilitation adherence: Patients who skip physiotherapy or ignore weight‑bearing restrictions are more likely to feel dissatisfied.

These factors interact. For instance, an elderly patient with diabetes operated on by a low‑volume surgeon who skips rehab is at the highest risk of regret.

Regret vs. Satisfaction: A Quick Comparison

The table shows that while overall satisfaction remains high (>80%), regret climbs noticeably after age 75, underscoring the importance of tailored pre‑operative counseling.

How Patients Can Minimize Regret

Armed with the data, patients can take concrete steps to keep regret low:

• Set realistic goals: Discuss activity expectations with the surgeon. Aiming to return to brisk walking rather than marathon running aligns with typical implant capabilities.
• Choose an experienced surgeon: Look for a surgeon who performs at least 50 TKAs per year and has a low revision rate (<2%).
• Commit to rehab: Attend at least 12 weeks of physiotherapy, focusing on range‑of‑motion and quadriceps strengthening.
• Manage comorbidities: Optimize blood sugar, lose excess weight, and quit smoking before surgery to reduce complications.
• Understand the implant: Different prosthetic knee designs (cruciate‑retaining vs. posterior‑stabilized) have subtle performance differences that may affect daily activities.

These actions directly address the five drivers listed earlier, lowering the odds of a high DRS score.

Related Concepts and Future Directions

Regret ties into a broader conversation about knee joint health. Alternative procedures, such as unicompartmental knee replacement (partial knee) or high tibial osteotomy, may present lower regret for specific patient groups (isolated medial compartment arthritis, younger active patients). Emerging technologies-robot‑assisted alignment and customized 3D‑printed implants-show promise in further reducing pain and improving functional outcomes, which could shrink the regret pool over the next decade.

For clinicians, tracking regret through the Decision Regret Scale alongside traditional metrics (infection rate, revision rate) creates a more patient‑centred quality dashboard.

Frequently Asked Questions

What exactly is the regret rate for knee replacement?

Regret rate refers to the percentage of patients who, after surgery, report that they would not choose the procedure again or would make a different decision. Most high‑quality registries place this figure between 2% and 4% at two‑year follow‑up.

How is regret different from surgical complications?

Complications are objective medical events (infection, fracture, etc.). Regret is a subjective feeling that may arise from complications, unmet expectations, or a combination of both. A patient can have no complications yet still feel regret if the functional outcome falls short of what they imagined.

Does age affect the likelihood of regret?

Yes. Studies consistently show higher regret in patients over 75, often because recovery is slower and comorbidities are more common. Younger patients (55‑64) typically have the lowest regret rates, especially when their activity goals are realistic.

Can choosing a different implant type lower regret?

Implant design can influence specific functional outcomes (e.g., deep‑knee flexion). While no implant eliminates regret entirely, selecting a prosthetic knee that matches your lifestyle-cruciate‑retaining for moderate activity or posterior‑stabilized for higher demands-helps align expectations with reality.

What role does surgeon experience play?

High‑volume surgeons (≥50 TKAs per year) report regret rates around half of those seen with low‑volume surgeons. Experience improves alignment accuracy, reduces intra‑operative errors, and often comes with better postoperative care pathways.

Is there a way to predict who will regret the surgery?

Predictive models combine age, BMI, pre‑operative pain scores, mental health status, and expectation questionnaires. Patients with high pre‑operative pain but low mental health scores and unrealistic activity goals are at the highest risk.

How does postoperative rehabilitation affect regret?

Adherence to a structured physiotherapy program reduces stiffness and improves strength, directly lowering the chance of persistent pain-a leading cause of regret. Studies show a 30% drop in regret scores for patients who complete at least 12 weeks of supervised rehab.

What should I ask my surgeon before deciding?

Ask about their annual TKA volume, average revision rate, the specific prosthetic model they recommend, expected functional outcomes, and the rehab protocol they follow. Also inquire how they handle patient expectations and whether they use the Decision Regret Scale pre‑ and post‑operatively.