Questions & Answers · Knee

What happens if you wait too long for a knee replacement?

Most people get the timing wrong — in both directions

A national study compared when knees with arthritis were actually replaced against when established criteria said they should have been. Only 9% were replaced at the appropriate time; 91% of the people whose knees qualified waited more than two years past that point. And at the other end, 26% of the replacements that did happen were judged premature — done before the arthritis and symptoms justified the risks (Ghomrawi et al., 2020).

So the question isn't just "am I waiting too long?" It's "am I in the 9%?" This page is about how to get there.

What waiting actually costs

• Function

  It keeps dropping while you wait

  In a study of patients on a knee replacement waiting list, function scores fell from 15.4 to 11.8 over roughly nine months of waiting (Clark et al., 2023). The knee you bring to surgery is the knee you rehab from.

• Muscle

  Protected legs shrink

  A painful knee gets protected, protected muscles weaken, and weaker legs make every recovery slower — surgical or not. Prehab with our in-house therapy team is how we fight this while you decide.

• The joint

  Stiffness and bowing progress

  Bone-on-bone knees can lose motion and drift into a bow-legged or knock-kneed alignment. Both can turn a routine replacement into a more complex one, with a stiffer starting point for rehab.

• Life

  The ledger

  The trips not taken and floors not sat on don't come back. The most common sentence we hear after surgery, verbatim: "I wish I'd done it sooner."

When "not yet" is the right answer

The American Academy of Orthopaedic Surgeons' guideline for knee arthritis puts nonsurgical care first — exercise and strengthening, weight management, anti-inflammatories, and injections when appropriate (AAOS Knee OA Guideline, 2022). We agree, and we do that care in-house. The honest "not yet" cases look like this:

• The X-ray and the pain don't match. Moderate arthritis with pain you can manage is a strengthening-and-check-in plan, not an operation.
• You haven't really tried conservative care. A structured course of physical therapy, activity changes and, where appropriate, injections buys some knees years. Done well, it's the plan — not procrastination.
• Something fixable is in the way. The AAOS surgical guideline notes that a BMI above 40 raises infection risk, advises an A1c below 6.5 before surgery, and recommends avoiding opioids before surgery (AAOS, 2023). Getting those in range first makes the surgery safer and the result better. That's a plan with a date on it, not a no.
• You're not ready. Surgery you aren't committed to rehabbing is surgery that underperforms. It's fine to say so; we'll keep you strong in the meantime.

When the line has been crossed

The line moves when all four of these are true, honestly assessed: bone-on-bone arthritis on standing X-rays; pain that interrupts sleep or decides your day; a real trial of conservative care that no longer holds; and your own decision that the trade no longer works. At that point, waiting another year usually doesn't buy anything except the costs above — and it doesn't make the eventual surgery smaller.

One more timing point worth knowing: there's no prize for being the youngest. An implant has a finite life — about 82% of total knees are still in place at 25 years in registry data (Evans et al., 2019) — so a knee replaced in your 40s is more likely to need a second operation than one replaced in your 60s. That's part of the premature-surgery problem in the Ghomrawi study, and part of why we say "not yet" when we mean it. Am I too young for this?

The "Am I a candidate?" path at Sterling Ridge

Start with our five-minute self-assessment — the same seven questions our surgeons ask in the exam room. Then a consult with Dr. Flowers or Dr. Chin: standing X-rays, an exam, your history, and a straight answer. If it's "not yet," you leave with a plan — therapy, weight or blood-sugar goals, a re-check date — and we'll tell you what would change the answer. If it's "yes," you'll know where you'd have surgery, what it costs, and what recovery looks like before you decide anything.

Sterling Ridge is one of the Houston area's leading joint replacement practices, and our surgeons replace hips and knees every week. Qualified patients have surgery as outpatients at the Sterling Ridge / Woodforest Ambulatory Surgical Center, with our rehab team on the same campus. Our surgeons also hold privileges at several area hospitals, so when your insurance plan or your medical history calls for a hospital setting, surgery is scheduled there instead. Consults are at The Woodlands, Spring and Woodforest offices, Monday through Friday, 8:00 AM to 5:00 PM — no referral needed.

Common questions

Sources

1. Ghomrawi HMK et al. Appropriateness criteria and elective procedures — total joint arthroplasty: timeliness of total knee replacement. Journal of Bone and Joint Surgery, 2020.
2. Clark LM et al. Patient-reported function while waiting for total knee arthroplasty, 2023.
3. American Academy of Orthopaedic Surgeons. Management of Osteoarthritis of the Knee (Nonarthroplasty), Clinical Practice Guideline, 2021/2022.
4. AAOS. Clinical Practice Guideline for Surgical Management of Osteoarthritis of the Knee, 2023 update.
5. Evans JT et al. How long does a knee replacement last? Lancet, 2019.

Medically reviewed by Keith W.V. Johnson, MD, FAAOS · Updated October 20, 2026