Why does my knee replacement hurt years later?

Last reviewed: September 29, 2026

Several things can cause it. New pain in a knee that had been doing well for years is worth having checked.

The most common cause found in knees that need a second operation years later is loosening, where the implant parts come loose from the bone. In a large series of repeat knee operations, infection was the leading cause in the first two years and loosening the leading cause after that. The plastic spacer between the metal parts also wears slowly, and heavy use or extra weight may speed this up. Some spacers have worn out early because of how a particular product was made or packaged. Parts that were not well aligned, or a knee not well balanced during surgery, are also linked to failure.

Infection can start years later too, when bacteria from the teeth, bladder or skin travel through the blood to the knee. Other causes include a knee that has become unstable, a break in the bone next to the implant, irritated tendons around the kneecap, and pain coming from the hip or lower back.

Surgeons usually start with an exam and X-rays. When infection is possible, blood tests for inflammation come next, and fluid may be drawn from the knee for testing.

In general:

• Fever, chills, redness, swelling, or pain at rest as well as with activity need prompt attention.
• Tell your dentist and other doctors that you have a knee replacement.
• Note when the pain started and what makes it worse, and bring that to the visit.

Drafted with AI assistance from published sources, reviewed and edited by Babak Sheikh, MD.

Sources:

• American Academy of Orthopaedic Surgeons. OrthoInfo: Total Knee Replacement. https://orthoinfo.aaos.org/en/treatment/total-knee-replacement/
• American Academy of Orthopaedic Surgeons. Diagnosis and Prevention of Periprosthetic Joint Infections, Clinical Practice Guideline. 2019. https://www.aaos.org/globalassets/quality-and-practice-resources/pji/pji-clinical-practice-guideline-final-9-18-19-.pdf
• Sharkey PF, et al. Why are total knee arthroplasties failing today—has anything changed after 10 years? J Arthroplasty. 2014. https://doi.org/10.1016/j.arth.2013.07.024
• Nickel BT, et al. Delamination and Oxidation in Compression-Molded Polyethylene. J Bone Joint Surg Am. 2025. https://doi.org/10.2106/JBJS.24.00857
• Berend ME, et al. Tibial component failure mechanisms in total knee arthroplasty. Clin Orthop Relat Res. 2004. https://doi.org/10.1097/01.blo.0000148578.22729.0e
• Cottino U, et al. Painful knee arthroplasty: current practice. Curr Rev Musculoskelet Med. 2015. https://doi.org/10.1007/s12178-015-9296-5

This is general information about what published research shows. It is not medical advice and it is not about your situation. Reading it does not create a doctor-patient relationship with me. I am a retired orthopedic surgeon and I do not see patients. Talk with your own doctor before changing anything about your care. If something feels suddenly or seriously wrong, get medical care promptly rather than waiting.

This page is provided as is. I make no guarantee that it is accurate, complete or current, and medical evidence changes. Use of it is at your own risk.

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