What Causes Knee Pain Years After Knee Replacement?

For most people a knee replacement provides lasting relief, but some develop pain months or years later. Understanding the possible causes helps you know when to seek advice.

Implant Wear or Loosening

Over many years, the implant's plastic surface can wear, or components can gradually loosen from the bone. This is one of the more common causes of late pain and may eventually require review surgery.

Infection

Although uncommon, an infection can develop around the implant even years later, sometimes from bacteria spreading through the bloodstream. Warning signs include pain with swelling, warmth, redness or fever, and it needs prompt medical assessment.

Other Causes

Late knee pain can also come from soft-tissue problems, inflammation of the joint lining, scar tissue, instability, mal-alignment, or a reaction to the implant. Sometimes the pain is referred from the hip or lower back rather than the knee itself.

What to Do

New or worsening pain years after a knee replacement should always be assessed. Examination and imaging, and sometimes blood tests, help identify the cause. Many problems can be managed without further surgery; others may need a revision procedure. Early assessment gives the best chance of a straightforward solution.