7 Revision Knee Replacement Signs You Should Not Ignore

Important: Not every painful knee replacement needs revision surgery. The diagnosis must be established before treatment is planned.

1

Persistent or worsening knee pain

Pain is one of the most common reasons patients seek review after knee replacement. The pattern matters.

Pain that never settled after surgery, pain that has gradually increased, or pain that appears after a long comfortable period may indicate that the knee needs further evaluation.

The location, timing and triggers of pain can provide useful clues. Pain during weight-bearing, pain at rest and sudden pain after an injury may have different causes.

2

Repeated or increasing swelling

Some swelling can occur during recovery, and the amount varies between patients. Swelling becomes more concerning when it is increasing, repeatedly returns, appears with warmth or redness, or develops after the knee had previously settled.

Swelling may be related to inflammation, instability, wear, infection or another problem around the joint. It should be interpreted together with the patient’s examination and imaging.

3

Instability or a feeling that the knee may give way

A replaced knee should feel sufficiently stable for everyday activities. A new sensation of buckling, shifting, wobbling or giving way may suggest an instability problem.

Instability can affect confidence, walking speed and stair use. It may also increase the risk of falling, particularly in older patients.

4

Increasing stiffness or loss of movement

Difficulty fully straightening or bending the knee can affect walking, chair transfers, stairs and personal care.

Stiffness may be related to scar tissue, swelling, implant position, infection or another mechanical issue. A reduction in movement that is getting worse deserves assessment.

5

A visible change in alignment or walking pattern

A leg that appears increasingly bowed, knock-kneed or differently aligned compared with before may indicate a mechanical problem.

Patients may also notice limping, uneven steps, difficulty balancing or the feeling that one leg has changed. These observations should be discussed during examination rather than judged from appearance alone.

6

New symptoms after a fall, twist or direct injury

Sudden pain, inability to bear weight, marked swelling or a noticeable change in the knee after a fall or injury requires prompt assessment.

The concern may involve a fracture around the implant, damage to the supporting structures or another injury. Revision surgery is only one possible treatment and depends on the findings.

7

Fever, wound drainage, redness or increasing warmth

Infection can occur soon after knee replacement or develop later. Symptoms can include increasing pain, swelling, redness, warmth, wound drainage, fever, chills or feeling generally unwell.

These symptoms should not be monitored at home for several days without advice. Contact the treating team or seek urgent medical assessment.

Usually discussed during routine follow-up

• Symptoms that are gradually improving
• Mild activity-related discomfort during rehabilitation
• Swelling that reduces with the advised recovery measures
• Temporary stiffness that is improving with the prescribed programme

Should be assessed sooner

• Symptoms that are getting worse instead of better
• New pain after a previously comfortable period
• Giving way, sudden loss of movement or inability to bear weight
• Fever, wound drainage, increasing redness, warmth or rapidly increasing swelling

Seek prompt medical advice for:

• High temperature, chills or feeling acutely unwell
• Pus or persistent drainage from the wound
• Rapidly increasing redness, warmth, pain or swelling
• Sudden inability to stand or walk after an injury
• New calf pain or marked calf swelling
• Chest pain or shortness of breath

1. Symptom history

The doctor asks when the pain began, whether the knee was ever comfortable after surgery, what activities trigger symptoms and whether there has been fever, drainage, injury or instability.

2. Physical examination

The surgeon assesses movement, swelling, warmth, tenderness, alignment, ligament stability, muscle function and walking pattern.

3. X-rays

Current X-rays may be compared with earlier images to look for changes in implant position, loosening, wear, fracture, alignment or bone loss.

4. Infection tests when required

Blood tests and analysis of fluid taken from the knee may be advised when infection is suspected. Antibiotics should not be started without medical advice when a planned diagnostic aspiration may be required, unless urgent treatment is necessary.

5. Additional imaging in selected cases

CT or other specialised investigations may be used when standard X-rays do not fully explain the symptoms or when surgical planning requires more detail.

Key takeaway

The purpose of assessment is not to rush into revision surgery. It is to understand why the knee is painful and choose the most appropriate treatment for that cause.

How do I know whether my knee replacement is failing?

Symptoms such as worsening pain, swelling, stiffness, instability or a change in function can suggest a problem, but they do not confirm implant failure. Examination, X-rays and selected tests are required.

Can a knee replacement become infected years later?

Yes. Joint replacement infection can occur soon after surgery or develop later. New persistent pain, swelling, warmth, fever or drainage requires medical review.

Is clicking after knee replacement always dangerous?

Not necessarily. Some patients notice sounds from an artificial joint without pain or instability. New clicking accompanied by pain, swelling, giving way or loss of function should be assessed.

Is revision knee replacement more complex than the first surgery?

It can be more complex because the surgeon may need to manage previous implants, bone loss, scar tissue, instability or infection. The exact procedure depends on the cause and the components involved.

When should I get a second opinion?

A second opinion may be useful when symptoms remain unexplained, revision surgery has been proposed, infection is suspected, or the patient wants to understand available options before making a decision.