Why are revision knee replacements failing?

The number of knee revisions worldwide has been steadily increasing. While being complex and expensive operations, a high percentage of knee revisions fail early. This study was conducted to evaluate the causes of failure of revision knee replacements.

This study retrospectively evaluated 95 patients following knee revision surgery and who underwent further knee revision operations. Indications for index revision as well as the reason for re-revision were recorded. Follow-up was from 30 to 97 months (mean 62 months).

The main cause of failure of revision knee replacements was infection (31 of 95, 32.6%) followed by aseptic loosening (30.5%). Indications for re-revision were instability in 12.6%, persistent stiffness in 10.5%, ongoing pain in 7.3%, extensor mechanism problems in 5.2%, and suspected metal allergy in one.

Infection and loosening continue to be the main reasons for failure of knee revisions. Improving outcomes for infection management and improved fixation methods may help reduce failed knee revisions.