Partial knee replacement: unicondylar arthroplasty
a.k.a. unicompartmental prothesis, hemiprosthesis
Some forms of knee arthritis can be treated by a partial knee prosthesis, i.e. by replacing the cartilage and meniscus only on one side of the knee joint, as shown below:
The surgery is less invasive, the skin incision shorter, rehab is faster, and the knee feels "more natural".
The following are stuations where a unicondylar arthroplasty can be discussed:
- degenerative arthritis of only the medial or the lateral side of the knee
- unicompartmental wear of the joint surfaces after meniscus surgery
- isolated bone necrosis, i.e. a portion of the load-bearing bone collapses because of insufficient blood supply in a limited area
- accelerated wear of the joint surface due to x-legs or bow-legs
The hospital stay is approximately 5-7 days, and the rehab takes 2-3 months. Full weight-bearing is permitted right away, under protection of two crutches for about 3 weeks.