A case of revision surgery after left knee arthroplasty A 67-year-old woman who had a unicondylar knee replacement in a private hospital in 2011 came to the hospital for another surgery 2 years after the surgery when she started to have severe pain. She came to the hospital for another surgery. We performed a revision surgery and replaced her knee with a total knee surface replacement. During the surgery, we felt that unicondylar replacement, if the indications are good, especially for young patients, can really preserve the bone volume and facilitate the revision after several years or more. The patient is now 72 hours post-operative and is walking in bed and can get out of bed to go to the bathroom by himself.