Revision Knee Replacement

A knee replacement is built to last many years, and most do. But no implant is permanent, and a replacement can loosen, wear, become unstable, stiffen, or become infected. When that happens, a second operation can remove some or all of the existing implant and replace it. That operation is called revision knee replacement.

At a glance: Revision knee replacement replaces a failed or failing knee implant. It is a longer and more complex operation than a first-time replacement, because bone and soft tissue have already been altered and because the cause of failure has to be identified before anything is replaced.

The joint replacement surgeons at Midwest Orthopaedics at Rush perform revision surgery, including for patients whose original replacement was performed elsewhere.

Signs your knee replacement may be failing

Some failures announce themselves; others develop slowly enough that patients accommodate them for years. Symptoms worth an evaluation include:

New or worsening pain in a knee that had settled after the original surgery — particularly pain with weight-bearing or with the first steps after sitting.
A feeling that the knee is loose, shifting, or giving way, or a lack of confidence going down stairs.
Swelling that will not settle, or that returns repeatedly.
Loss of motion — a knee that will not straighten fully or bend as far as it once did.
Warmth, redness, drainage, or fever, which can indicate infection and should be evaluated promptly rather than watched.
A clunk, click, or grinding that is new.
Pain after a fall, which may indicate a fracture in the bone around the implant.

Pain by itself is not a diagnosis, and not every painful replacement needs revision. But the causes that respond best to treatment are generally the ones caught early, and infection in particular changes the entire plan depending on how long it has been present.

Why a knee replacement fails

Identifying the reason matters more than anything else in this operation, because revising a knee without knowing why the first one failed tends to reproduce the failure. Common causes:

Aseptic loosening. The bond between implant and bone breaks down over time and the component loosens. The most common reason for late revision.
Infection. Can appear soon after the original surgery or years later, sometimes seeded from an infection elsewhere in the body. Infection changes the entire treatment plan and is ruled in or out first.
Polyethylene wear. The plastic bearing surface wears over years of use. Wear particles can provoke an inflammatory response that dissolves bone around the implant — a process called osteolysis, which can loosen a component that was otherwise well fixed.
Instability. The knee gives way or feels unreliable because soft-tissue balance or component position does not hold it steady through its range of motion.
Stiffness. A knee that never regained adequate motion, or that lost it later to scar tissue.
Malposition. Components positioned outside the intended range, which can cause pain, accelerated wear, and instability.
Periprosthetic fracture. A break in the bone around the implant, usually after a fall, sometimes in bone weakened by osteolysis.
Extensor mechanism problems. Injury or failure of the quadriceps or patellar tendon, or problems involving the kneecap component.

Who is more likely to need revision

Revision risk is not evenly distributed. Factors that raise it include:

Younger age at the time of the original replacement. A knee replaced at 55 has more years and more cycles to survive than one replaced at 75. This is the single most consistent risk factor.
Higher body weight, which increases load across the implant.
High-impact activity sustained over years.
Diabetes, immunosuppression, smoking, or prior joint infection, which raise infection risk specifically.
Prior surgery on the same knee before the replacement.
Inflammatory arthritis and the medications used to treat it.

None of these means a replacement will fail. They shape how closely a knee is followed and what is discussed before a first replacement in a younger patient.

How your surgeon finds the cause

A revision workup is a process of elimination, and infection is ruled out before anything else because it changes every subsequent decision.

History and examination. When the pain started, whether there was ever a pain-free interval after the original surgery, what makes it worse, and how the knee behaves under load. A knee that was never comfortable points somewhere different from one that was fine for eight years.
X-rays, including weight-bearing and comparison with previous films where available. Serial X-rays showing a progressive lucent line around a component are strong evidence of loosening.
Blood tests. Inflammatory markers such as ESR and CRP screen for infection. Normal values make infection much less likely; raised values prompt further investigation.
Joint aspiration. Fluid is drawn from the knee and analysed for cell count, differential, and culture. This is the most direct test for periprosthetic joint infection and is done whenever infection is a possibility.
Advanced imaging. CT for component rotation and bone loss, MRI with metal-suppression sequences for soft tissue, and nuclear medicine bone scans in cases where loosening is suspected but not visible on plain films.

Bring your operative report and implant records if you can obtain them. Knowing exactly which components are in place helps with planning — some implants have specific removal requirements — though their absence does not prevent an evaluation or an operation.

If your knee replacement is painful, unstable, or simply not working the way it should, the first step is finding out why. We evaluate patients whose original replacement was performed elsewhere, and we will tell you plainly whether revision is the right answer.

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If the workup does not identify a clear cause, revision is generally not the answer. Operating on an unexplained painful knee replacement has a poor track record, and a surgeon who tells you they do not yet know why your knee hurts is being straight with you.

Alternatives to revision surgery

Not every failing knee replacement needs a full revision, and the alternative depends entirely on the cause:

Manipulation under anesthesia. For stiffness in the months after the original surgery, the knee can be moved through its range under anesthesia to break up scar tissue — without opening the joint. Timing matters; this works far better early than late.
Arthroscopic release. For some cases of scarring, an arthroscopic procedure may address the problem without revising components.
Polyethylene exchange alone. When the plastic bearing has worn but the metal components remain well fixed and correctly positioned, exchanging only the liner is a smaller operation than a full revision.
Debridement with implant retention (DAIR). For an infection caught early — typically within a few weeks of onset, with well-fixed components — the joint can be washed out, the plastic liner exchanged, and the metal components left in place, followed by a course of antibiotics. It avoids a much larger operation, but it only works within a narrow window.
Bracing and physical therapy. For mild instability, or where a patient is not a surgical candidate, non-operative management may be the better path.

These options are discussed against the specific cause. What they have in common is that they are less invasive than a full revision, and where one of them fits, it is generally preferred.

How revision differs from a first knee replacement

A first replacement works with a knee that has never been operated on. A revision does not, and that changes several things:

Bone loss. Removing existing components takes bone with it, and osteolysis may already have destroyed more. Filling those defects may require metal augments, cones or sleeves, or bone graft.
Bone graft. Defects may be filled with the patient's own bone (autograft) or donor bone (allograft), sometimes in structural pieces for larger deficiencies.
More constrained implants. When ligaments are deficient or absent, revision implants that provide more built-in stability are used, often with stems that extend into the femur and tibia to gain fixation in healthier bone further from the joint.
Scar tissue and soft tissue. Previous incisions and scarring affect exposure, closure, and healing.
Longer operation, greater blood loss, and a higher likelihood of an overnight or multi-night hospital stay.

What the operation involves

Revision is performed under regional or general anesthesia. The surgeon works through the previous incision where possible, removes the existing components along with any cement, assesses the bone that remains, and reconstructs what is missing before implanting new components. Restoring the joint line to its correct height and rebalancing the soft tissues are as important as the implants themselves — a knee reconstructed at the wrong joint line rarely feels right afterward.

Component choice follows from what the ligaments can still do. A knee with intact collateral ligaments may accept implants similar to a primary replacement; one with deficient ligaments needs greater built-in constraint, up to a hinged implant in the most severe cases.

Revision for infection

An infected knee replacement is treated differently, and how long the infection has been present largely determines the approach.

Early infection. Caught within a few weeks of onset with well-fixed components, DAIR may be possible — washout, liner exchange, retained metal, then antibiotics.
Two-stage revision. The established approach for established infection. In the first operation all components and cement are removed and an antibiotic-loaded cement spacer is placed in the knee. Intravenous antibiotics follow, typically for several weeks, guided by what grew on culture. Once markers and clinical signs indicate the infection has cleared, a second operation removes the spacer and implants the new replacement. The whole process commonly takes several months, and mobility is limited in between.
One-stage revision. In selected cases — a known organism sensitive to antibiotics, good soft tissue, a patient without major risk factors — removal and reimplantation are done in a single operation. It is used more selectively.

Eradicating infection takes priority over everything else. A new implant placed into an incompletely treated infection will fail.

Recovery after revision knee replacement

Recovery is individual and generally slower than after a first replacement.

In hospital. Walking usually begins with a physical therapist within a day. Hospital stays are typically longer than after a primary replacement.
Weight-bearing. Restrictions are more common than after a first replacement, particularly where bone graft, augments, or a periprosthetic fracture are involved. Follow them — they protect the reconstruction while bone heals.
Pain management. Typically a combination of regional anesthesia, non-opioid medication, and a short course of opioid medication. Opioids carry risks of dependence and side effects; the goal is the lowest effective dose for the shortest period, and most patients transition off them within weeks.
Blood clot prevention. Blood thinners, early mobilisation, and sometimes compression devices. Report new calf pain, swelling, or shortness of breath immediately.
Wound care and infection prevention. Revision wounds are watched closely, particularly where there are multiple prior incisions. Report increasing redness, drainage, or fever.
Physical therapy. Range of motion and quadriceps strength, progressing more gradually than after a primary replacement.

Planning for home

Revision recovery asks more of you at home than a first replacement did, and planning ahead is worth the effort. Arrange help for the first stretch, clear routes through your home for a walker, sort out stairs, put what you use daily within easy reach, and consider a raised toilet seat and shower rail. Some patients spend time in a rehabilitation facility before going home, and it is easier to arrange that before surgery than after.

Risks and complications

Revision knee replacement carries the risks of any major joint operation, several of them at higher rates than a first-time replacement:

Infection — higher risk than in primary replacement, and the complication that most often drives further surgery.
Blood loss and a greater likelihood of transfusion.
Bone loss or fracture during component removal.
Nerve or blood vessel injury, uncommon but more likely where scar tissue is extensive.
Wound healing problems, particularly with multiple previous incisions.
Blood clots in the leg or lung.
Extensor mechanism injury, which is difficult to treat and has a significant effect on function.
Persistent pain or stiffness. Some patients continue to have symptoms after revision.
Further revision. Revision implants have a shorter expected lifespan than primary implants.

Long-term outcomes

Most patients who undergo revision for a clearly identified mechanical problem get meaningful relief from the symptom that brought them in — the loose component, the instability, the worn bearing. That is what the operation is designed to do, and it generally does it.

What revision does not reliably do is return the knee to the way it felt at its best after the original replacement. Function after revision is, on average, somewhat less than after a well-functioning primary replacement, and revision implants do not last as long. Results are better when the cause was clear and mechanical, and less predictable when the original problem was unexplained pain. Your surgeon should be candid with you about which situation you are in.

Knee specialists at Midwest Orthopaedics at Rush

Revision knee replacement is performed by board-certified, fellowship-trained orthopedic surgeons at Midwest Orthopaedics at Rush. Our knee and sports medicine surgeons completed subspecialty fellowship training after residency, and the group treats knee conditions across the full range — from first-time injuries through complex reconstruction.

Revision is technically demanding and benefits from surgeons who perform it regularly. Our joint replacement surgeons handle complex revisions including significant bone loss, instability requiring constrained implants, and staged treatment of infected replacements — and we routinely see patients referred from outside practices for a second opinion.

Browse our knee specialists to read individual profiles, see where each surgeon practices, and request an appointment directly. Appointments are available across our Chicago-area locations.

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Frequently asked questions

What is the success rate of revision knee replacement?

Outcomes depend heavily on why the revision was needed. Revisions for a clear mechanical cause — loosening, wear, instability — generally do well. Revisions for infection or for unexplained pain are less predictable, and infection revisions carry a real risk of recurrence. Your surgeon can discuss what the evidence suggests for your specific situation rather than a single overall figure.

How long does a knee replacement last?

Longevity varies with age, weight, activity level, implant type, and component position. Registry data shows most primary knee replacements still functioning well at fifteen years and beyond, but no implant is permanent and individual results vary.

How many times can a knee replacement be revised?

There is no fixed number, but each revision removes more bone and makes the next one harder. Second and third revisions are performed, and each becomes progressively more complex, with a greater likelihood of needing highly constrained implants. This is part of why surgeons are cautious about revising a knee without a clear cause.

Is revision knee surgery worse than the original replacement?

It is a bigger operation with a longer recovery and higher complication rates, and function afterward is on average somewhat less than after a well-functioning primary replacement. That said, it is performed because the current knee is not working, and the comparison that matters is against leaving the problem alone.

How do I know if my knee replacement has failed?

New or worsening pain, a knee that feels loose or gives way, swelling that will not settle, lost motion, or warmth and fever. Any of these is worth an evaluation. Some causes are far easier to address early — infection especially.

Can revision be done if my first replacement was somewhere else?

Yes. Bring your operative report and implant records if you can get them, since knowing which components are in place helps with planning. Not having them does not prevent an evaluation.

Does every failing knee replacement need a full revision?

No. Depending on the cause, options include manipulation under anesthesia for stiffness, exchanging only the plastic liner, or washout with liner exchange for an early infection. The workup determines which applies.

What happens if my knee replacement is infected?

Treatment depends on how long the infection has been present. Early infections may be treated with washout, liner exchange, and antibiotics. Established infections are usually treated in two stages — removing the implant, placing an antibiotic spacer, treating with intravenous antibiotics, then implanting a new replacement once it has cleared. That process commonly takes several months.

If your knee replacement is painful, unstable, or not working the way it should, an evaluation is the first step in finding out why. Schedule an appointment with the knee specialists at Midwest Orthopaedics at Rush.

This page is general information about a surgical procedure and is not medical advice. Talk with a physician about your own symptoms, imaging, and treatment options.

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