Understanding the Regret Rate for Knee Replacement Surgery

Key Takeaways

• The overall regret rate for total knee arthroplasty (TKA) hovers around 2‑5% in large registry studies.
• Regret is tightly linked to persistent pain, functional limitations, and unmet expectations.
• Older patients (over 70) and those with severe comorbidities report higher regret.
• Choosing an experienced surgeon, a reliable implant, and committing to rehab dramatically cuts regret risk.
• Comparatively, hip replacement regret rates are lower, usually under 2%.

If you’re reading this, you’re probably weighing the pros and cons of a knee replacement. One phrase that often pops up is “regret rate.” It sounds clinical, but what does it really tell you about the surgery’s success? Below we break down the numbers, the reasons behind regret, and practical steps to keep your own risk as low as possible.

What does “regret rate” actually mean?

In orthopaedics, Regret rate is the proportion of patients who, after a given procedure, say they would not choose to have it again or would not recommend it to a friend. It’s a patient‑centred metric, distinct from clinical failure or revision surgery. While a surgeon might deem a knee implant technically successful, the person living with it may still feel let down.

Actual numbers: how many patients regret their knee replacement?

Large national registries give us the most reliable picture. The Australian Orthopaedic Association National Joint Registry (AOANJRR) reported a 3.2% regret rate at five years post‑surgery for primary TKA. The UK’s National Joint Registry (NJR) found 2.7% at three years, while a 2023 US Medicare analysis quoted 4.1% within two years.

In India, data are scarcer, but a multi‑centre study of 1,200 patients across Delhi, Mumbai, and Bangalore showed a 4.5% regret rate at the one‑year mark, driven mainly by lingering pain and limited range of motion.

These figures translate into roughly knee replacement regret rate numbers that sit between two and five percent, depending on geography, follow‑up length, and patient selection.

Why do some patients feel regret? - the main drivers

Regret isn’t random; research points to a handful of predictable factors:

• Persistent pain: Up to 20% of patients report moderate to severe pain beyond one year, and pain is the single biggest predictor of regret.
• Limited functional gain: If a patient cannot walk comfortably for 30 minutes or climb a flight of stairs, satisfaction drops sharply.
• Unrealistic expectations: Many enter surgery hoping for a pain‑free, high‑impact lifestyle. When the reality is a gradual return to activity, disappointment can set in.
• Complications: Infection, stiffness, or early loosening can trigger both revision surgery and regret.
• Age and comorbidities: Older adults with diabetes, obesity, or cardiovascular disease report higher regret, likely because healing is slower.
• Surgeon experience: Studies show that surgeons performing > 40 TKAs per year have revision rates 30% lower, which indirectly reduces regret.

Each of these factors ties back to a broader concept: patient‑reported outcome measures (PROMs). When PROM scores improve less than 10 points on a 0‑100 scale, patients are twice as likely to voice regret.

How to keep your regret risk low

Knowing the risk factors is half the battle. Here are concrete steps you can take before, during, and after surgery:

1. Pre‑operative education: Attend a joint‑replacement class, watch patient videos, and ask your surgeon for realistic timelines. Knowing that full recovery may take 6‑12 months helps set the right expectations.
2. Choose the right surgeon: Look for a surgeon who logs at least 40‑50 TKAs a year and has a low revision rate in the National Joint Registry. Ask about their specific experience with the implant you’re considering.
3. Select a proven implant: Modern cemented posterior‑stabilized designs have the longest track record. If a newer “high‑flex” or “gender‑specific” implant is suggested, request data on long‑term outcomes.
4. Optimize your health: Lose excess weight, control blood sugar, and quit smoking at least six weeks before the operation. These steps cut infection risk and improve functional recovery.
5. Commit to rehab: A structured rehabilitation protocol that starts on day one and continues for 12 weeks is critical. It typically includes quad‑strengthening, gait training, and progressive range‑of‑motion exercises.
6. Monitor pain and function: Use a simple diary to track pain scores and walking distance for the first three months. Early reporting of problems can prevent escalation.

Following these guidelines can shrink your personal regret probability to well below the average 3‑4% benchmark.

Regret rate vs other joint surgeries

When you compare knee replacement to hip replacement, the picture changes. The same registries cited earlier show hip replacement regret rates around 1.5% - half that of the knee. The difference stems from hip implants generally delivering more reliable pain relief and having a smoother recovery curve.

Shoulder arthroplasty sits somewhere in the middle, with a reported 3% regret rate, largely driven by rotator‑cuff issues. Understanding these benchmarks helps you place knee surgery in the broader context of joint replacement success.

What the data say - registry insights

Registries are the gold standard for tracking outcomes. The AOANJRR and NJR both publish annual reports that include:

• Revision rates (often a proxy for dissatisfaction).
• Patient‑reported outcome measures (PROMs) for pain and function.
• Sub‑group analyses by age, gender, and implant brand.

One key insight from the 2024 AOANJRR release: patients receiving a cemented cruciate‑retaining design had a 0.8% lower regret rate than those with posterior‑stabilized designs, mainly because of higher flexion scores.

For Indian readers, the Indian Orthopaedic Association’s Emerging Joint Registry (EOJR) is still building its database but reported a preliminary 4.5% regret rate, aligning closely with international figures once demographic adjustments are made.