What is Total Knee Replacement?

Total Knee Replacement, also known as Total Knee Arthroplasty, is a surgical procedure used to treat severe knee arthritis and advanced knee joint damage. During the procedure, the damaged cartilage and worn surfaces of the knee joint are removed and replaced with specially designed metal and plastic components that recreate the smooth movement of a healthy knee.

The knee is made up of three main compartments where the femur (thigh bone), tibia (shin bone), and patella (kneecap) meet. Over time, arthritis, injury, or joint degeneration can cause the cartilage in these areas to wear away. This can lead to pain, stiffness, swelling, instability, and difficulty walking or performing everyday activities.

Modern knee replacement techniques and implant designs are highly advanced and are tailored to the patient’s anatomy, activity level, and severity of joint damage.

Who is Suitable for Total Knee Replacement?

Total Knee Replacement may be suitable for patients who have significant knee pain, stiffness, and reduced mobility that interfere with daily life and have not improved with conservative treatment.

Patients who may be candidates include those with:

• Severe Knee Arthritis: Commonly osteoarthritis, rheumatoid arthritis, or post-traumatic arthritis.
• Persistent Knee Pain: Pain that continues during walking, climbing stairs, standing, or even at rest.
• Reduced Mobility and Function: Difficulty walking long distances, exercising, or performing normal activities.
• Advanced Joint Damage: Significant cartilage loss, deformity, or bone-on-bone contact seen on imaging.
• Failure of Non-Surgical Treatments: Limited improvement despite physiotherapy, medications, injections, weight management, braces, or activity modification.
• Knee Deformity: Bow-legged or knock-kneed alignment caused by joint degeneration.
• Night Pain or Sleep Disturbance: Ongoing discomfort affecting quality of sleep and overall well-being.

Suitability for surgery depends on several factors, including age, general health, activity level, weight, bone quality, and patient expectations. Some younger active patients and older adults may both benefit from knee replacement, depending on their symptoms and level of disability.

An orthopaedic assessment, clinical examination, and imaging investigations such as X-rays or MRI scans help determine whether Total Knee Replacement is the most appropriate treatment option.

Benefits of Total Knee Replacement

For appropriately selected patients, Total Knee Replacement can significantly improve comfort, mobility, and quality of life.

Potential benefits may include:

• Pain Relief: Reduction in chronic knee pain caused by arthritis or joint degeneration.
• Improved Mobility: Easier walking, climbing stairs, standing, and daily movement.
• Better Knee Function: Improved joint stability, strength, and overall knee performance.
• Improved Quality of Life: Increased independence and ability to participate in work, hobbies, travel, and social activities.
• Correction of Deformity: Improved knee alignment in patients with bowing or joint collapse.
• Reduced Stiffness: Increased range of motion and smoother joint movement.
• Improved Sleep: Less night pain and discomfort.
• Long-Term Durability: Modern knee implants are designed to provide long-lasting function for many patients over many years.

Many patients can return to low-impact activities such as walking, swimming, cycling, golf, and light recreational exercise after recovery and rehabilitation.

Types of Total Knee Replacement?

Standard Total Knee Replacement

This is the most commonly performed type of knee replacement. The damaged surfaces of the femur and tibia, and often the underside of the kneecap, are replaced with artificial components designed to recreate normal joint movement.

Cemented Total Knee Replacement

In this technique, specialised bone cement is used to secure the implant components to the bone. This is the most widely used fixation method and is suitable for many patients.

Cementless Total Knee Replacement

Some implants are designed to allow bone to grow directly into the implant surface for long-term fixation. This approach may be considered in selected patients with good bone quality.

Robotic-Assisted Total Knee Replacement

Robotic-assisted technology may help improve surgical precision, implant positioning, and alignment. The robotic system assists the surgeon during the procedure but does not perform the surgery independently.

Patient-Specific Knee Replacement

Advanced imaging and customised surgical planning may be used to better match the implant positioning to the patient’s individual anatomy.

Complex or Revision Total Knee Replacement

Some patients with severe deformity, ligament damage, bone loss, or failed previous knee replacements may require more specialised implants and reconstruction techniques.

Alternative Options to Total Knee Replacement

Not all patients with knee pain require Total Knee Replacement. In many cases, non-surgical treatments or less invasive procedures may help manage symptoms, particularly in earlier stages of arthritis.

Alternative treatment options may include:

• Physiotherapy: Strengthening exercises, flexibility programs, and gait training to improve joint support and movement.
• Activity Modification: Avoiding high-impact activities that aggravate symptoms.
• Weight Management: Reducing body weight may help decrease stress on the knee joint.
• Pain Relief Medications: Anti-inflammatory medications or other pain management strategies.
• Cortisone Injections: Temporary reduction of inflammation and pain within the joint.
• Viscosupplementation Injections: Lubricating injections that may help selected patients with mild to moderate arthritis.
• Bracing and Supports: Knee braces may assist with alignment and stability.
• Walking Aids: Canes or walkers may reduce pressure on the joint.
• Partial Knee Replacement: In selected patients where arthritis affects only one compartment of the knee, a Unicompartmental Knee Replacement may be considered instead of a full replacement.
• Arthroscopic Surgery: In limited cases, minimally invasive surgery may help address mechanical symptoms, although it is generally less effective for advanced arthritis.
• Lifestyle and Exercise Programs: Low-impact exercise such as swimming, cycling, and supervised strengthening programs may help maintain mobility and reduce symptoms.

When knee pain becomes severe and conservative treatments no longer provide adequate relief, Total Knee Replacement may become the most effective long-term option for improving function and quality of life.

Preparation Before a Total Knee Replacement?

Preparing properly before a Total Knee Replacement can help improve recovery, reduce complications, and optimise surgical outcomes. Your orthopaedic surgeon and healthcare team will guide you through the preparation process based on your individual health and needs.

Before surgery, patients may be advised to:

• Attend an Orthopaedic Assessment: A detailed consultation, examination, and review of imaging, such as X-rays or MRI scans, is performed to assess the severity of joint damage and plan surgery.
• Complete Pre-Operative Investigations: Blood tests, heart tests, medical clearance, and other assessments may be required before surgery.
• Review Medications: Some medications, including blood thinners, anti-inflammatory medications, or supplements, may need to be adjusted or temporarily stopped before surgery.
• Optimise General Health: Managing diabetes, blood pressure, heart conditions, and other medical issues may help reduce surgical risks.
• Stop Smoking: Smoking may impair wound healing and increase the risk of complications.
• Maintain Physical Activity: Gentle strengthening and physiotherapy exercises may help improve muscle support and assist recovery after surgery.
• Prepare the Home Environment: Arranging mobility aids, removing tripping hazards, and organising support at home may help make recovery safer and easier.
• Discuss Post-Operative Rehabilitation: Understanding the rehabilitation plan and expected recovery timeline may help patients prepare mentally and physically for surgery.
• Plan Support After Surgery: Assistance with transport, meals, shopping, and daily activities may be needed during the early recovery period.

Patients are usually provided with fasting instructions and hospital admission details before the procedure.

What Happens During a Total Knee Replacement?

Total Knee Replacement is performed in a hospital under either general anaesthesia or spinal anaesthesia, often with additional pain management techniques.

During the procedure:

• The Knee Joint is Accessed: A surgical incision is made at the front of the knee to expose the damaged joint surfaces.
• Damaged Cartilage and Bone are Removed: Worn and arthritic portions of the femur, tibia, and sometimes the underside of the kneecap are carefully removed.
• The Joint is Prepared: The bone surfaces are shaped to fit the artificial implant components accurately.
• Implants are Inserted: Metal components are attached to the femur and tibia, with a smooth plastic spacer placed between them to allow movement.
• Patella Resurfacing May be Performed: In some cases, the underside of the kneecap is also resurfaced.
• Alignment and Stability are Checked: The surgeon carefully assesses knee motion, stability, alignment, and implant positioning before completing the procedure.
• The Incision is Closed: The tissues and skin are repaired, and dressings are applied.

Some surgeons may use robotic-assisted or computer-assisted technology to help improve surgical precision and implant alignment.

The procedure typically takes between 1 and 2 hours, depending on the complexity of the surgery and individual patient factors.

What to Expect After a Total Knee Replacement?

Recovery after Total Knee Replacement occurs gradually over weeks to months. Most patients experience significant improvement in pain and mobility as healing and rehabilitation progress.

After surgery, patients may expect:

• Hospital Recovery: Most patients remain in the hospital for several days, depending on their recovery progress and overall health.
• Pain Management: Pain-relief medications, ice therapy, and other strategies are used to manage discomfort.
• Early Mobilisation: Walking and gentle movement often begin shortly after surgery, sometimes on the same day or the following day.
• Physiotherapy Rehabilitation: Structured physiotherapy plays an important role in improving strength, flexibility, balance, and walking ability.
• Swelling and Bruising: Mild to moderate swelling, stiffness, and bruising are common during the early recovery phase.
• Use of Walking Aids: Crutches, a walker, or a cane may be needed temporarily during recovery.
• Improving Knee Function Over Time: Range of motion and mobility gradually improve with rehabilitation and exercise.
• Return to Daily Activities: Many patients can resume basic daily activities within several weeks, although full recovery may take several months.
• Scar Healing: The surgical scar gradually matures and softens over time.

Patients are usually encouraged to continue low-impact exercise and maintain an active lifestyle following recovery.

Total Knee Replacement Prognosis

Total Knee Replacement is generally considered a highly successful procedure for appropriately selected patients with advanced knee arthritis or joint damage.

Many patients experience:

• Significant Pain Relief: Reduction in chronic arthritis-related knee pain.
• Improved Mobility and Function: Better walking tolerance, movement, and participation in daily activities.
• Enhanced Quality of Life: Increased independence and improved ability to remain active.
• Long-Term Implant Survival: Modern knee replacements may last many years, particularly with appropriate activity modification and ongoing care.

Recovery outcomes vary depending on factors such as age, general health, body weight, rehabilitation participation, muscle strength, bone quality, and pre-existing medical conditions.

Most patients can return to low-impact activities such as:

• Walking
• Cycling
• Swimming
• Golf
• Light recreational exercise

High-impact activities, heavy repetitive loading, and contact sports may place increased stress on the implant and may not be recommended.

Total Knee Replacement Risks

Potential risks may include:

• Infection: Superficial or deep infection around the joint replacement.
• Blood Clots: Deep vein thrombosis (DVT) or pulmonary embolism.
• Bleeding or Bruising: Around the surgical site.
• Stiffness: Some patients may experience reduced knee movement following surgery.
• Persistent Pain: A small number of patients may continue to experience discomfort after surgery.
• Implant Wear or Loosening: Artificial components may wear or loosen over time.
• Nerve or Blood Vessel Injury: Rare injury to nearby structures.
• Instability or Dislocation: Uncommon but may occur in some patients.
• Fracture: Bone fracture around the implant during or after surgery.
• Anaesthetic Risks: Complications related to anaesthesia or underlying medical conditions.
• Need for Revision Surgery: Some patients may eventually require further surgery if complications develop or implants wear out.

Careful surgical planning, modern techniques, rehabilitation, and appropriate follow-up help reduce the risk of complications.

What if Total Knee Replacement is Delayed?

Delaying Total Knee Replacement may allow symptoms and joint damage to progressively worsen over time.

Potential consequences of delaying surgery may include:

• Increasing Pain: Ongoing arthritis may worsen pain during walking, standing, and daily activities.
• Reduced Mobility: Progressive stiffness and reduced movement may limit independence and quality of life.
• Muscle Weakness: Reduced activity may contribute to weakening of the surrounding muscles.
• Joint Deformity: Bowing, collapse, or worsening alignment changes may become more severe.
• Reduced Physical Fitness: Ongoing pain may limit exercise and overall health.
• Difficulty Performing Daily Tasks: Walking, stairs, driving, shopping, and self-care activities may become more challenging.
• Reduced Sleep and Well-being: Chronic pain may contribute to fatigue, frustration, and reduced mental well-being.
• Progressive Joint Damage: Advanced arthritis may continue to damage bone, cartilage, and surrounding structures.

In some patients, delaying surgery for prolonged periods may also make surgery and recovery more technically challenging due to worsening deformity, stiffness, or muscle loss.

An orthopaedic assessment can help determine the most appropriate timing for surgery based on symptoms, imaging findings, activity limitations, and overall health goals.

FAQs About Total Knee Replacement

How long does a Total Knee Replacement usually last?

Modern Total Knee Replacement implants are designed to be durable and long-lasting. Many knee replacements may last 15–20 years or longer, depending on factors such as activity level, body weight, implant type, and overall joint health.

Will I set off airport security scanners after a knee replacement?

Yes, the metal components used in a knee replacement may sometimes trigger airport security scanners. Patients can usually inform security staff that they have undergone a joint replacement procedure.

Can both knees be replaced at the same time?

In some patients, bilateral knee replacement surgery may be performed during the same operation. However, this depends on the patient’s overall health and fitness, the severity of the arthritis, and the surgeon’s recommendation.

When can I drive after a total knee replacement?

Driving may be possible several weeks after surgery, once patients can safely operate a vehicle, comfortably bend the knee, and are no longer using strong pain medications. Recovery time varies by individual and by which knee was operated on.



Will the artificial knee feel completely normal?

Although many patients achieve excellent pain relief and improved mobility, an artificial knee may not feel exactly the same as a natural knee. Some patients may notice mild stiffness, clicking sensations, or awareness of the implant, particularly during certain movements.