Revision total knee replacement involves re-operation on the knee due to a variety of potential causes including:
- Polyethylene wear (plastic).
- Loosening of one or more of the components.
- Ligament injury.
- Kneecap (patella) dislocation.
The overall results of revision surgery are still quite successful, but less predictable than a first time operation. Soft tissue scarring, and stiffness is more common. Bone quality can often be diminished, which can hinder the success of implant fixation.
One of the most common situations for revision surgery involves wear of the plastic spacer. This can create inflammation in the bone (osteolysis). This can lead to bone inflammation, weakening, and destruction. Current sterilizing techniques are much improved over those of the 80's and 90's. This will likely serve to greatly improve the longevity of the plastic component.
The change of the plastic spacer has been the least difficult of the revision procedures. When the metal femur or metal tibial components need to be removed, bone weakness often can impair the reimplantation process. Occasionally large, structural bone grafts are required to restore the bone integrity, and secure the implants. Sometimes small, particle bone grafts can be used to help the bone in the healing process to reconstitute its strength.
The complication risk is slightly increased in revision surgery including infection, ligament injury, tendon injury, stiffness or loosening due to poor bone quality.
The recovery time occasionally maybe shorter than a normal knee replacement, as in the example of a plastic exchange. It may also be longer in situations that involve more complete component revision surgery, or in situations of infection