Pain and swelling after activity are the hallmarks of osteoarthritis, and many people describe their knee as feeling stiff, especially first thing in the morning or if they’ve been immobile for a while. The knee might become swollen at the back (known as a Baker’s cyst), and sometimes the knee becomes permanently ‘bow-legged’ or ‘knock-kneed’ in shape. You may find your knee grinds or makes a creaking noise when bending.

Initially, you might feel some pain going up and down stairs or when twisting or kneeling on the knee, but as the arthritis progresses, pain may become ever-present or disturb your sleep. There may be wasting of the muscles supporting your knee (especially your quads muscles on the front of the knee). The knee may also feel unstable or as if it may give way.

Knee osteoarthritis is an irreversible process, but in the early stages, studies have shown that exercise and physio are helpful for knee arthritis and help to keep the affected knee strong. If you’re overweight, trying to lose excess weight will reduce the stress on your knees. Some patients may choose to take a painkiller after a busy day on their feet. Presently, there isn’t compelling evidence to support the routine use of injection treatment with hyaluronic acid or platelet-rich plasma (PRP) for knee osteoarthritis, and we try to avoid using steroid injections for osteoarthritis because, in the long-term, it degrades the joint further.

Many patients find that if they adapt their exercise regime to keep active whilst reducing impact activity (such as running), they can manage their symptoms well in the early stages.

When you come to the clinic, I’ll be asking you lots of questions about how your knee is affecting you and the impact it has on your work, your family life, as well as your sports and hobbies. I’ll want to understand your expectations, whether you’re medically well, and whether you can cope with surgery and the necessary rehabilitation.

Sometimes, people have medical conditions such as diabetes or are on blood thinning medications, and occasionally, people may need to lose a little bit of weight before they undergo surgery.

Knee replacement surgery is an excellent option if you have exhausted conservative options and you have pain and symptoms that are impacting your life daily.

Partial knee replacement surgery may be a good option if knee osteoarthritis affects the medial or lateral compartment of the knee. In other words, it’s designed to replace one-half of the knee. It’s also known as a unicompartmental knee replacement.

Partial knee replacement surgery is less invasive than a total knee replacement, and the recovery is a little quicker and more comfortable. They don’t last forever, although on average, we can anticipate that a partial knee replacement will last for 15 years before it fails – this is why the vogue has been to offer this surgery to older rather than younger people. If you’ve reached 80 years of age and you only have arthritis in one compartment of your knee, it’s much less likely that you’ll go on to develop arthritis in other areas of your knee.

Partial knee replacement isn’t suitable for you if you have arthritis in addition to areas of your knee, if your knee has become very deformed, or if your anterior cruciate isn’t intact.

The surgery is usually carried out under spinal anaesthesia (to numb the leg) and sometimes with additional light sedation. A short incision is made vertically over the front of the knee to one side of the knee cap. The worn sides of the joint are cut away using a ‘jig’ to place the cuts accurately, and then the bone is prepared to receive the new implant. This consists of metal components for the femoral and tibial sides of the joint, separated by a polyethylene plastic spacer. The implant is fixed in place with cement, and the incision is closed with stitches. My preference is to use a ‘Physica ZUK’ partial knee replacement prosthesis, which is a fixed-bearing device.

After the surgery, you will be seen by a physiotherapist who will assist you in standing and walking with crutches and get you started with physio exercises. Most people will spend a night in hospital and will use crutches for a few days. If you’re working, you’ll need to take six or more weeks off work, depending on your occupation. You can return to driving when you’re able to get in and out of the car OK if you have an automatic car and have had left knee surgery, or, if the surgery was on your right knee when you’re able to control the vehicle and carry out an emergency stop, which may be around six weeks.

If you’re struggling with advanced knee osteoarthritis that involves more than one compartment of the knee, a total knee replacement may be the best option for you, particularly if there is a big deformity because of the arthritis process.

Knee replacement surgery is now performed as a day-case procedure and occasionally an overnight stay. We found that patients recover better and quicker in their own homes with the right support and advice in place. Usually, it’s carried out under spinal anaesthesia (to numb the leg fully) and light sedation.

The first step involves making an incision a few inches long over the front of the knee and then removing the worn cartilage surfaces by making precise cuts into the ends of the thigh bone (femur) and shin bone (tibia). These cuts are made accurately using a jig scaffold, and the implant, consisting of femoral and tibial metal components, is fixed using a special cement. A polyethylene (plastic) spacer is placed between the two metal components, acting as a shock absorber and providing a surface for the metal bearings to pivot and swivel.

I typically do not replace the back of the kneecap (patella) unless it is fully worn out, as research has shown no significant difference in outcomes between replacing and not replacing the kneecap. The entire procedure takes about one to two hours, and the incision is then stitched closed.

After the surgery, you’ll be taken to recovery, and the spinal block will gradually wear off, with normal sensation returning to your leg. A physiotherapist will then encourage you to take your first steps on your new knee.

You’ll be given effective pain management so that you can progress with your physio exercises when you return home. Performing the rehab ‘homework’ prescribed by your physiotherapist and attending regular sessions is crucial. Patients who actively participate in rehab, work on achieving a good range of motion and swiftly rebuild muscle strength around the knee have the best outcomes post-surgery.

Some discomfort during rehabilitation is common but manageable, and regular icing will help reduce swelling. In the first few days, focusing on fully straightening the knee is essential, so avoid sleeping with a pillow under your leg at night.

At the two-week stage, we meet again in the clinic to check on the wound’s healing, and we’ll do an X-ray to ensure excellent alignment. We would then meet again at the six-week and six-month stages.

Keep the wound clean and dry for the first two weeks after the operation. You can shower using a protective cover to keep the knee dry, but avoid taking baths.

It is important to understand that while knee replacement surgery is highly effective, it cannot replicate the function of your native knee. Your knee may feel stiff in the first few months, and kneeling on the floor may be uncomfortable. However, many people adapt by finding alternative ways to get to the ground if required for their occupation.

Regarding sports and activities after a total knee replacement, it is essential to remember that knee replacements are artificial and are not as durable as a ‘native’ knee. High-impact activities such as running are not advised, as they can cause the implant to wear down and may feel uncomfortable. However, many people can return to playing doubles tennis, golf, and even skiing. Cycling and swimming are highly recommended. It can take at least a year or two for your knee to feel fully ‘settled in’.

The amount of time needed off work depends on your occupation. Desk-based workers may require around a month, while those with manual jobs may need six to twelve weeks off work.

Knee replacement is a very successful operation, and whilst risks can never entirely be removed, my team and I do our very best to minimise risk wherever possible.

Potential risks of knee replacement surgery include infection (less than 1%), fracture to the tibia or fibula bone (rare), early loosening, bleeding, damage to nerves or blood vessels, and blood clots.

Knee replacements have excellent longevity, and studies have shown that at 20 years, 80% of knee replacements still function well.