Failed Total Knee Replacement

When a Knee Replacement May Not Function as Expected

A total knee replacement aims to reduce pain and restore more comfortable movement. In some cases, symptoms continue or return over time. Understanding these patterns can help identify whether knee replacement failure might be contributing to your symptoms.

Persistent Pain After Knee Replacement

Persistent pain after knee replacement may relate to soft-tissue irritation, implant loosening, alignment issues, or factors outside the prosthesis, such as hip or spine conditions. A structured clinical review helps differentiate these possibilities.

Stiffness and Reduced Movement

Some people experience difficulty bending or straightening the knee after surgery. This may relate to scarring, soft-tissue tightness, or early stiffness that did not fully resolve. In some cases, reduced motion can limit daily activity or contribute to discomfort on stairs or inclines.

Instability or a Feeling of Giving Way

A knee that feels unstable may be related to soft-tissue imbalance, ligament laxity, or component positioning. This can occur slowly over time or may follow a particular event. Instability can affect confidence in walking, particularly when changing direction or walking on uneven ground.

Recurrent Swelling or Warmth

Some swelling is common after surgery, but swelling that persists long-term may relate to knee prosthesis issues such as wear debris, synovial irritation, or less commonly infection. This may be accompanied by warmth or fullness after activity.

Additional Patterns That May Suggest Further Review

These symptoms may develop gradually or appear unexpectedly and can be related to different knee replacement complications.

Difficulty With Functional Tasks

Challenges with prolonged standing, rising from a chair, or navigating stairs may indicate reduced strength, stiffness, or subtle mechanical issues that warrant evaluation.

Mechanical Sensations

Some people describe clicking or grinding that feels different from their early post-operative phase. While some sounds are expected, new mechanical sensations may be relevant when symptoms persist.

Reduced Confidence in the Knee

A sense that the knee does not move predictably, even without pain, may reflect an imbalance between components and surrounding soft tissues. This can influence gait and weight-bearing patterns over time.

Common Causes of Failed Total Knee Replacement

Several mechanical and biological factors are recognised as common causes of knee replacement failure. Understanding these helps explain why symptoms may develop.

Implant Loosening

Loosening of the knee implant may occur over time due to wear, alignment issues, or underlying bone quality. Loosening can cause pain with weight-bearing and difficulty with prolonged walking. Imaging and, in some cases, specific tests may be used to assess fixation.

Polyethylene Wear

The spacer between the metal components may show signs of wear after many years. This can lead to inflammation, mechanical symptoms, or gradual changes in stability.

Alignment or Rotational Issues

Small variations in component alignment or limb rotation may influence how forces travel through the knee. This can affect comfort, function, or stability, especially during activity that involves bending or twisting.

Soft-Tissue Imbalance

The ligaments around a replaced knee continue to contribute to stability. If these tissues become stretched, tight, or imbalanced, symptoms such as instability or stiffness may occur.

Infection

Infection after knee replacement may present with pain, swelling, warmth, or stiffness. Some infections appear early, while others develop slowly. Diagnosis may involve blood tests, imaging, or joint aspiration.

Fractures Around the Implant

Less commonly, a fracture may occur around a prosthetic component. These injuries usually follow a fall or significant impact and require prompt assessment.

Additional Factors That May Influence Knee Function

Not all symptoms come from the implant itself. In some cases, nearby structures or general health factors play a role.

Muscle Weakness or Deconditioning

Reduced quadriceps or hip strength may alter movement patterns, affect balance, and increase strain on a replaced knee.

Scar Tissue and Soft-Tissue Irritation

The capsule, tendons, or soft tissues may become irritated or develop dense scar tissue that limits motion or comfort during activity.

Coexisting Joint or Spine Conditions

Hip arthritis, lumbar spine issues, or foot and ankle alignment may contribute to altered load through the knee and influence postoperative symptoms.

How a Failed Knee Replacement Is Assessed

Assessment for failed knee replacement aims to clarify the source of your symptoms and identify which structures or processes may be involved.

Clinical Examination

Your surgeon will assess your movement, alignment, strength, stability, and walking pattern. These findings help guide the next steps in the investigation.

Imaging

X-rays assess component position and bone integration. A CT scan may help evaluate alignment or rotation if needed. Ultrasound or other imaging may be used to assess soft tissues or swelling.

Blood Tests and Joint Aspiration

If infection is a possibility, blood tests may be arranged. In some cases, removing a small amount of joint fluid helps clarify infection or inflammatory changes.

Review of Surgical History

Previous operation notes, implant details, and rehabilitation history can provide important context for current symptoms.

Treatment Pathways for a Failed Knee Replacement

Management depends on the underlying cause, your symptoms, and your overall health.

Non-Surgical Management

Options may include physiotherapy to improve movement or strength, activity modification, or medication to manage inflammation. These approaches may be suitable when symptoms are mild or when testing shows that the implant is stable.

Revision Total Knee Replacement

Revision total knee replacement may involve removing some or all components of the previous implant and placing new parts designed to improve stability and alignment. This may be considered when symptoms significantly affect daily activities and when investigations show a clear mechanical or structural cause.

Results vary depending on individual circumstances. Your surgeon will discuss risks, potential benefits, and expected recovery to help you make an informed decision.

Infection Management

If an infection is confirmed, treatment may include antibiotics and, in some cases, surgical cleaning or staged procedures. The approach depends on the type of bacteria and how long the infection has been present.

When to Seek Review for Knee Concerns After Replacement

You may consider an assessment if you notice:

• Pain that persists or increases over time
• Stiffness or movement restriction that limits daily tasks
• Recurrent swelling or warmth
• Clicking, catching, or locking
• A sensation of instability or giving way
• Difficulty performing activities that were previously manageable
• Uncertainty about imaging findings or your surgical history

A knee surgeon in Sydney, such as Dr Jonathan Negus, can help determine why symptoms may be occurring and discuss suitable options based on your assessment and imaging findings.

Next Steps

Understanding why a knee replacement is not performing as expected can be complex. A structured review provides clarity and helps identify whether the issue relates to the implant, surrounding tissues, or other contributing factors.

With clear information and a tailored plan, many people feel more confident about the next steps in managing their symptoms.

If you have ongoing symptoms after a previous knee replacement and would like clarity about possible causes or treatment pathways, you can arrange a consultation with Dr Jonathan Negus to discuss your condition, investigations, and management options.

This information is intended as a general guide and may not apply to every situation. Assessment and treatment recommendations vary depending on individual circumstances. Please speak with a qualified health professional for advice specific to your condition.