Total knee replacement involves surgically removing the damaged cartilage and bone from the knee joint and replacing it with metal and plastic components. This procedure is recommended for patients with severe arthritis or joint damage who have not found relief from other treatments. The new knee joint significantly reduces pain and improves function and quality of life.
The surgery itself is painless due to anaesthesia, but post-operative pain and discomfort are expected. Pain management strategies, including medication and physiotherapy, are essential during recovery.
Total knee replacement is very effective for severe knee conditions. Most patients experience significant pain relief and improved function, with the majority reporting a substantial improvement in their quality of life.
The actual surgical procedure for a total knee replacement usually takes about one to two hours. This can vary slightly depending on the complexity of the case, the type of implant being used, and whether it's a first-time or revision surgery. Some patients with more severe joint deformity or previous surgeries around the knee may require additional time. Before surgery begins, there’s also preparation time in the operating theatre, including anaesthesia and sterile setup, which adds another 30 to 60 minutes. So while the time spent under anaesthesia may be closer to two to three hours in total, the knee replacement itself is typically completed within about 90 minutes. After surgery, patients are monitored in recovery before being transferred to the ward. Most people remain in hospital for a few days, depending on how quickly they regain mobility, manage pain, and meet physiotherapy goals. It's natural to feel that the entire process takes longer than expected, but much of the focus during and after surgery is on ensuring safety, reducing the risk of complications, and setting the stage for a smooth recovery.
A total knee replacement can last many years—often 15 to 20 years or more—depending on several factors such as the patient’s age, activity level, weight, and the type of implant used. Modern knee prostheses are highly durable, and advancements in surgical techniques and materials have improved longevity even further. For many patients, especially those over 60, a single knee replacement may last the rest of their lives. However, younger and more active individuals may place greater stress on the joint, potentially leading to earlier wear and tear. In such cases, revision surgery may eventually be required. A key factor in implant longevity is post-operative care and lifestyle. Maintaining a healthy weight, avoiding high-impact activities (like running or jumping), and adhering to rehabilitation plans can significantly prolong the life of the replacement. Infections or complications such as loosening or misalignment can also impact how long the joint lasts. Regular follow-up with an orthopaedic surgeon is essential to monitor the condition of the implant over time. X-rays and clinical assessments help detect early signs of wear or loosening so that any necessary interventions can be planned early. Overall, knee replacements are considered a long-term solution for managing severe arthritis and restoring mobility.
A total knee replacement is designed to be a long-term solution, and in many cases, the new joint can last 15 to 20 years or even longer. Advances in surgical technique and implant technology have improved the durability of modern knee prostheses, meaning that for many patients—especially those over 60—a single knee replacement may last a lifetime. However, the longevity of the joint can be influenced by several factors. These include your activity level, weight, overall health, and how well you follow post-operative instructions. High-impact activities, excessive strain on the joint, or trauma can accelerate wear and lead to earlier revision surgery. That said, even younger or more active individuals who take care of their new knee can often enjoy many years of improved function and pain relief. Surgeons typically use long-term follow-up and occasional imaging to monitor the knee for signs of wear or loosening. While no implant can be guaranteed to last forever, most patients find that a total knee replacement significantly enhances their mobility and quality of life, often for decades. If problems do arise, revision surgery is an option, though it’s generally more complex than the initial operation.
Like any major surgery, total knee replacement carries certain risks, although serious complications are relatively uncommon. The most common risks include infection, blood clots (deep vein thrombosis or pulmonary embolism), and issues related to wound healing. Infection can range from superficial to deep within the joint, sometimes requiring further surgery if not managed with antibiotics. Blood clots are a concern after any lower limb operation, so preventive measures such as blood thinners, compression stockings, and early mobilisation are routinely used. Some patients may also experience stiffness, reduced range of motion, or ongoing discomfort even after recovery, though most people report significant improvement compared to their pre-surgery condition. In rare cases, the prosthetic components may loosen or wear out over time, leading to instability or the need for revision surgery. Nerve or blood vessel injury is also possible, though extremely uncommon. Some individuals may notice numbness around the incision site or changes in knee sensation, which often improve over time. While these risks sound concerning, they must be weighed against the potential benefits—particularly if knee pain and limited mobility are affecting quality of life. Careful surgical planning, experienced surgeons, and a commitment to post-operative care all help to minimise these risks and optimise outcomes.
Recovery from a total knee replacement is a gradual process that typically spans several weeks to months. Immediately after surgery, most patients spend a few days in hospital where pain management, wound care, and the beginning of physiotherapy are priorities. The goal during this early phase is to get the knee moving and reduce the risk of complications such as blood clots or stiffness. By the end of the first week, many patients are able to walk short distances with a walker or crutches. Physiotherapy continues either at home or in an outpatient setting and plays a vital role in regaining strength, flexibility, and balance. Most people can resume light daily activities—such as walking around the house or preparing simple meals—within a few weeks. By six weeks, many patients are able to walk unaided and start to feel more confident on their feet. Driving may be possible if the knee is strong enough and reaction times have returned to normal. Full recovery, including return to low-impact activities like swimming or cycling, can take anywhere from three to six months, and sometimes longer. Every recovery is a little different, so regular follow-up appointments are important to track progress and adjust rehabilitation plans as needed.
The recovery process after a total knee replacement is carefully structured to help patients regain mobility, manage pain, and return to everyday activities as safely and efficiently as possible. It begins right after surgery, often within hours, with early mobilisation. Most patients are encouraged to start moving their leg and walking short distances with assistance from a physiotherapist on the same day or the following morning. During the first few days in hospital, the focus is on pain control, preventing complications like blood clots, and beginning basic rehabilitation exercises. Patients typically stay in hospital for two to four days, although this can vary depending on individual circumstances. Once discharged, recovery continues at home or in a rehabilitation facility. Physiotherapy plays a central role during this phase—exercises focus on restoring knee movement, improving strength, and building confidence with walking and daily tasks. A walking aid such as a frame or crutches is usually needed for the first few weeks. By around six weeks, many people can walk short distances unaided and resume light household duties. Full recovery can take three to six months, sometimes longer, depending on age, fitness, and preoperative joint condition. Regular follow-ups help monitor progress and guide rehabilitation. Patience and persistence are key during this stage.
While total knee replacements are designed to be long-lasting, there is a possibility that a second surgery—known as a revision knee replacement—may be needed in the future. For many people, especially those aged over 60 at the time of their first surgery, the original knee replacement can last 15 to 20 years or more and may never need to be redone. However, several factors can influence the need for revision surgery. These include wear and tear of the implant over time, loosening of components, infection, or mechanical issues such as instability or misalignment. Younger or more active individuals may place more stress on the joint, which can increase the likelihood of needing a revision at some point. That said, improvements in implant design and surgical techniques have significantly increased the durability of modern prostheses. Many patients enjoy decades of improved mobility and pain relief after their initial surgery. If a revision is needed, it tends to be a more complex operation than the first, often requiring specialised implants and a longer recovery period. Your surgeon will monitor the knee over time with regular follow-up visits and imaging to catch any signs of wear early and guide decision-making if future surgery becomes necessary.
Most patients regain a significant range of motion after total knee replacement, but it's important to understand that it may not return to exactly what it was before arthritis or injury affected the joint. The typical goal after surgery is to achieve around 0 degrees of knee extension (being able to fully straighten the leg) and at least 110 to 120 degrees of flexion (bending the knee), which is usually enough for everyday activities like walking, climbing stairs, sitting in a chair, and getting in and out of a car. Regaining full motion depends on several factors, including the stiffness of the knee before surgery, the presence of scar tissue, muscle strength, and how diligently a patient follows their physiotherapy plan. Those who had limited mobility before the operation may find it more challenging to achieve a wide range of motion afterwards, though most still experience a substantial improvement. It’s also worth noting that progress isn’t always linear. Some patients feel stiff or swollen at times during recovery, especially in the early weeks. Ongoing rehabilitation and stretching exercises play a big role in optimising outcomes, and your surgeon and physiotherapist will guide you on what’s realistic based on your personal circumstances.
After a total knee replacement, most patients can expect to regain a good range of motion—enough to walk comfortably, climb stairs, sit, and carry out daily activities. However, returning to a completely “full” range of motion like that of a healthy, natural knee may not always be possible. Typically, the goal is to achieve full extension (being able to straighten the leg completely) and at least 110 to 120 degrees of flexion (bending the knee), which is usually sufficient for most routine movements. The degree of motion you regain will depend on several factors, including how stiff your knee was before surgery, the presence of scar tissue, and how closely you follow your rehabilitation plan. It’s also worth noting that progress is gradual. Swelling and stiffness in the early weeks are normal, but consistent physiotherapy helps improve flexibility and strength over time. Some people may achieve more than 130 degrees of bend, while others may fall slightly short depending on their individual circumstances. With dedication to your recovery exercises and guidance from your physiotherapist, it’s very likely you’ll experience a major improvement in mobility—even if the final range of motion doesn’t exactly match that of a completely natural knee.