Knee revision surgery removes some or all of the parts of the original prosthesis and replaces them with new ones.
It is a longer, more complex procedure than primary knee replacement surgery that requires extensive planning, and specialized implants and tools to achieve a good result.
In a primary total knee replacement, the surfaces of the femur, tibia, and patella are replaced with a metal implant.
During primary total knee replacement, the knee joint is replaced with an implant, or prosthesis, made of metal and plastic components.
Over time problems such as implant wear and loosening may require a revision procedure to replace the original components.
Different types of revision surgery:
only one implant or component of the prosthesis has to be revised.
all three components—femoral, tibial, and patellar—are removed or replaced and the bone around the knee needs to be rebuilt with augments of metal pieces that substitute for missing bone, or bone graft.
In most cases, specialized implants with longer, thicker stems that fit deeper inside the bone for extra support are utilized.
In revision surgery longer stems fit more securely into the bones and provide stability.
Indications for revision surgery:
Implant Loosening and Wear
During the initial surgery the knee prosthesis is either cemented into position or bone was expected to grow into the surface of the implant.
The implant id firmly fixed, but overtime, it may loosen from the underlying bone, causing the knee to become painful.
Loosening: high-impact activities, excessive body weight, and wear of the plastic spacer between the two metal components of the implant are all factors.
Younger patients undergoing knee replacement may “outlive” the life expectancy of their artificial knee.
Tiny particles may wear off the plastic spacer and accumulate around the joint causing an immune reaction that attacks the healthy bone around the implant, leading osteolysis.
With osteolysis the bone around the implant deteriorates, making the implant loose or unstable.
A nuclear medicine bone scan may help determine if the prosthesis has loosened from the bone.
A magnetic resonance imaging (MRI) scan or a computed tomography (CT) scan may be used to help determine the condition of the bone.
The procedure is longer and more complex than primary total knee replacement, it has a greater risk of complications.
Poor wound healing
Reduced range of motion or stiffness in the knee.
Infection in the wound or the new prosthesis.
Bleeding
Blood clots
Bone fracture during surgery
Damage to nerves or blood vessels
Pulmonary embolism
Medical problems.
The procedure is more complex and takes longer to perform than primary total knee replacement.
Such surgery takes from 2-3 hours.
If cement was used in the primary total knee replacement, it is removed.
The original implant is removed and the bone surfaces prepared and augmented for the revision implant.
Rarely, bone graft material may be used to help rebuild the knee.
The graft may come from the patient’s bone or from a donor.
Recovery after revision surgery is usually slower than recovery after primary total knee replacement.
A continuous passive motion machine (CPM) is a knee support that slowly moves the knee to help restore early range of
Graded compression stockings, and blood thinners are used to prevent thromboembolism.
The risk of infection is slightly higher after revision surgery than after primary total knee
The majority of patients with revision surgery experience favorable long-term outcomes, including relief from pain and increased stability and function.