A total knee replacement (TKR), also known as total knee arthroplasty, is considered when other treatments for knee pain and disability have failed to provide relief. Some common reasons to consider TKR include:

1. Severe Pain: When knee pain is severe and interferes with daily activities, despite conservative treatments such as medications, physical therapy, or injections.

2. Decreased Mobility: If knee pain and stiffness limit mobility and prevent participation in activities that were once enjoyed.

3. Functional Limitations: Difficulty performing basic tasks like walking, climbing stairs, or getting in and out of chairs due to knee pain and stiffness.

4. Joint Damage: When X-rays or other imaging tests reveal significant damage to the knee joint, such as severe arthritis, osteoarthritis, rheumatoid arthritis, or other conditions affecting the knee joint.

5. Failure of Other Treatments: If other treatments like medications, corticosteroid injections, physical therapy, or assistive devices have failed to provide adequate relief.

6. Worsening Symptoms: Progressive worsening of symptoms despite attempts at conservative management.

It's important for individuals considering TKR to discuss their symptoms, medical history, and treatment options with their healthcare provider. The decision to undergo TKR is typically made collaboratively between the patient and their healthcare team after considering various factors such as age, overall health, severity of symptoms, and expected benefits and risks of surgery.