What Is Knee Replacement Surgery?

Total knee replacement (total knee arthroplasty) is a highly successful surgical procedure performed in patients with advanced knee osteoarthritis. The aim is to eliminate pain permanently, restore range of motion, and improve overall quality of life.

During the operation, the worn-out cartilage surfaces of the knee joint are removed and replaced with specially designed metal and polyethylene components. This allows the patient to regain a stable, functional and pain-free knee joint.

Knee osteoarthritis (gonarthrosis) develops as a result of ageing, previous injuries, ligament or meniscus tears, and biomechanical problems that lead to the gradual wear of the joint cartilage. Pain often begins in the 40s and tends to worsen over the years. Initially, it is felt only during movement or weight-bearing, but later it may persist even at rest and at night.

Over time, this chronic pain and stiffness cause:

• Reduced walking distance,
• Difficulty climbing and descending stairs,
• Stiffness and loss of motion in the knee,
• Significant limitations in daily and social activities.

When performed on the right patient, knee replacement surgery can help the individual:

• Get rid of longstanding knee pain,
• Regain functional movement and confidence,
• Return to daily life and social activities with improved comfort.

Who Is a Candidate for Knee Replacement?

Total knee replacement is considered for patients who have:

• Severe knee pain that does not improve with medication, rest, injections, or physical therapy,
• Advanced cartilage loss and deformity of the joint on X-ray,
• Marked limitation in walking, stair climbing and daily activities,
• Night pain and pain at rest,
• Progressive functional decline and reduced quality of life,
• Daily need for painkillers due to persistent knee pain.

When deciding on surgery, the orthopaedic surgeon typically focuses on the following questions:

1. Does the patient experience night pain that disturbs sleep?
2. Is there a constant or increasing need for pain medication?
3. Has the patient’s walking distance significantly decreased?
4. Is stair climbing becoming increasingly difficult?
5. Is there clear joint space narrowing and cartilage destruction on radiographs?

If several of these questions are answered “yes”, total knee replacement is often the most effective and long-term treatment option.

How Long Does a Knee Prosthesis Last?

Modern total knee prostheses typically have a lifespan of approximately 15–25 years. This duration may vary depending on:

• The surgeon’s technique,
• The quality and design of the implant,
• The patient’s body weight,
• Level of daily activity and type of work or sports,
• Bone quality and overall joint alignment.

With appropriate patient selection, correct implant positioning and good post-operative care, knee prostheses can function safely and comfortably for many years.

Surgical Process

Knee replacement surgery can be performed under general anesthesia or regional anesthesia (spinal/epidural). The choice of anesthesia is made according to the patient’s general health status and preference.

Before the operation, an epidural catheter or peripheral nerve block may be placed to provide effective post-operative pain control. The surgical procedure itself usually takes about 1.5 hours. Most patients stay in the hospital for 1–2 days after surgery.

Post-operative course typically includes:

• First day: The patient is mobilised with a walker or crutches and can meet basic personal needs.
• A personalised rehabilitation and exercise program is explained in detail.
• Within about 6 weeks: Most patients are able to return to the majority of their daily activities.

Early mobilisation reduces the risk of blood clots, supports muscle strength and accelerates recovery.

What Are the Risks of Knee Replacement Surgery?

Although total knee replacement is a safe and commonly performed procedure, like any surgery it carries certain risks and potential complications, such as:

• Complications related to anesthesia,
• Injury to nerves or blood vessels during surgery,
• Fracture of the bone while preparing the joint,
• Excessive bleeding or need for blood transfusion,
• Infection around the wound or prosthesis,
• Blood clots in the leg veins (deep vein thrombosis) and, rarely, pulmonary embolism,
• Early loosening of the prosthesis or mechanical problems.

These risks are minimised by careful pre-operative evaluation, appropriate patient selection, modern surgical techniques and close follow-up after surgery.

How Long Does Pain Last After Knee Replacement?

Experiencing pain after surgery is normal and expected, especially in the early period:

• First 48 hours: This is usually the most painful period. Pain is controlled with strong painkillers, epidural catheter or nerve blocks.
• First 3 weeks: Intermittent mild to moderate pain or discomfort is common, especially during movement and exercises.
• Persistent or severe pain: Ongoing, severe pain that does not improve over time may indicate problems such as prosthesis loosening, infection, malalignment or muscle imbalance.

In such cases, it is important to inform your orthopaedic surgeon and undergo appropriate evaluation. Using the pain medication prescribed by your doctor as recommended will make the rehabilitation process more comfortable.

For more detailed information about recovery after knee replacement surgery, please refer to our dedicated article on post-operative rehabilitation and follow-up.