Revision Knee Replacement Surgery
Revision knee replacement means replacing part or all of a previous knee replacement, and it covers an unusually wide range. At one end it is a minor adjustment exchanging a worn plastic bearing. At the other it is a major reconstruction replacing significant amounts of bone. What determines which one you are facing is why the first replacement failed.
Revision knee replacement is a larger and less predictable operation than a first replacement, and it rewards a surgeon who has worked out why the original failed before starting. Steven Struhl, MD is board certified in orthopedic surgery and separately in sports medicine, has practiced in New York since 1991, is a Fellow of the American Academy of Orthopaedic Surgeons, and operates at NYU Langone Orthopedic Hospital. He reviews prior operative reports and imaging as part of every revision evaluation.
Why a Knee Replacement Needs to Be Revised
- Plastic Wear: the polyethylene bearing wearing over years, which is the most predictable reason and often the simplest to address.
- Aseptic Loosening: components losing their fixation to bone without infection, frequently following wear particle release.
- Infection: the most serious cause, and the one that changes the entire treatment plan.
- Instability: ligament balance that has failed, producing a knee that gives way.
- Stiffness: motion that never returned or was lost, limiting function.
- Malalignment: components positioned in a way that loads the knee abnormally.
- Periprosthetic Fracture: a break in the bone around the implant.
Establishing which of these applies is the entire evaluation, because revising a knee without knowing why the first one failed tends to reproduce the failure.
Evaluating a Failed Knee Replacement
Pain after a knee replacement is not by itself an indication for revision, and revising a painful knee without a demonstrated cause has a poor record. The evaluation is systematic. Radiographs are compared against earlier films to identify loosening, wear, and position change. Blood tests including inflammatory markers screen for infection, and joint aspiration is performed whenever infection is a possibility, because an infected revision is a fundamentally different operation. CT assesses component rotation and bone stock. Prior operative reports establish which implants are in place, which determines what is needed in the operating room.
What Revision Surgery Involves
Revision is longer and more complex than a primary replacement, and the exposure alone frequently takes as long as an entire first replacement.
- Careful Exposure: working through scar tissue while protecting the extensor mechanism.
- Component Removal: taking out the existing implants while preserving as much bone as possible.
- Bone Loss Assessment: determining what remains and how to reconstruct what does not.
- Augments and Cones: metal wedges, sleeves, or cones filling defects where bone is missing.
- Stemmed Components: longer stems extending into the femur and tibia to gain fixation beyond the damaged bone.
- Increased Constraint: implants that provide more built in stability where ligaments can no longer do it.
- Bone Graft: used to reconstruct contained defects.
Where infection is the cause, treatment is typically staged. The implants are removed, an antibiotic spacer is placed, intravenous antibiotics are given over several weeks, and the new replacement is implanted only once the infection is cleared.
Recovery After Revision Knee Replacement
- Weeks One to Six: weight bearing as the reconstruction allows, which is more variable than after a first replacement, with motion started early.
- Weeks Six to Twelve: support weaned, motion and strength advanced.
- Months Three to Six: endurance and gait rebuilt, and most patients returning to daily activity.
- Months Six to Twelve: the final result settling, generally more gradually than after a primary replacement.
Expectations and Risks
Being direct about this is more useful than reassurance. Revision knee replacement carries higher rates of infection, stiffness, and further revision than a first replacement, and the functional result is generally not as good. Most patients still gain substantial pain relief and a knee that works for daily life, which is why the operation is worth doing when it is indicated.
Although most people are happy with the result, complications can occur and they are worth understanding before deciding. If you are undecided, waiting until you are confident is a reasonable position, since revision is elective in most circumstances other than infection.
Schedule a Revision Knee Consultation in New York City
A knee replacement that hurts, gives way, or has lost motion deserves a full investigation rather than an immediate second operation, because the reason for the failure determines what the revision has to accomplish. Dr. Struhl evaluates failed knee replacements at his Manhattan and White Plains offices and reviews prior operative reports and imaging. Contact Dr. Steven Struhl to schedule a consultation.
