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Partial knee replacement
A partial knee replacement can treat an arthritic joint by replacing only the most damaged compartment of the knee. It's less invasive than a full knee replacement and, supported by our expert care, offers a quicker recovery time.
At HCA UK we offer:
- Appointments with leading knee specialists confirmed within one working day
- Advanced knee surgery including minimally invasive and robotic-assisted techniques
- Quality care: 97% of our orthopaedic patients rated us as ‘very good’ or ‘excellent’
What is a partial knee replacement?
Partial knee replacement surgery, sometimes called unicompartmental knee surgery, is a procedure to treat advanced osteoarthritis affecting a single compartment of the knee joint. A surgeon will replace the damaged part of the joint with a prosthesis. The surgery is designed to improve your mobility while reducing pain, helping you enjoy a better quality of life. It involves a smaller incision than a total knee replacement contributing to a faster recovery time.
Is partial knee resurfacing the same as a partial knee replacement?
It can be difficult to understand the difference between the types of knee replacement, especially with different surgeons using different naming conventions. A partial knee replacement is sometimes called ‘partial knee resurfacing surgery’, ‘unicompartmental knee replacement’, a ‘unicondylar knee arthroplasty’ or even an ‘unicondylar knee replacement’. You might also hear some people call a partial knee replacement a ‘uni’ or ‘half knee replacement’.
What is unicompartmental osteoarthritis?
Unicompartmental osteoarthritis of the knee is a degenerative condition that affects only one part of the knee, leaving the other regions healthy. To understand why you might experience unicompartmental osteoarthritis, it’s important to look at the anatomy of the knee joint.
Your knee connects three bones: the femur (thigh bone), patella (kneecap) and tibia (shin bone). Two protruding lumps on the bottom of your femur (femoral condyles) make up the top of the knee. The bottom of your knee is made up of the upper tibia (the tibial plateau) and the kneecap sits in front.
As well as the three bones, there are three compartments in your knee (the medial compartment, the lateral compartment and the patellofemoral compartment). When we refer to ‘unicompartmental osteoarthritis’, it means that just one of the compartments is damaged. It can happen in any compartment but is most commonly found in the medial compartment.
Unicompartmental osteoarthritis is caused by the cartilage within your joint wearing away. Cartilage stops your bones from rubbing together and acts as a shock absorber in the joint. It can thin over time, however, resulting in your joint feeling painful or stiff and your range of motion being restricted. If this happens and non-surgical options have been exhausted, you might need a partial knee replacement.
If I have a partial knee replacement, will it cure my knee arthritis?
If you have osteoarthritis in only one compartment of your knee, a partial knee replacement will cure it by removing the damaged compartment. However, it’s important to remember that arthritis could later affect another compartment. If this is the case, you might need a total knee replacement.
Who can benefit from partial knee replacement surgery?
A partial knee replacement may be effective if your knee arthritis only affects one compartment in your knee joint. This can also be called:
- Medial knee arthritis: Arthritis on the inside compartment of the knee joint
- Lateral knee arthritis: Arthritis on the outside compartment of the knee, furthest from your other knee joint.
Partial knee replacements used to be reserved for older patients but are now sometimes recommended for younger, more active people with arthritis. With modern knee replacements lasting up to 20 years, having the procedure earlier in life means you can preserve more of your knee joint but may need another replacement in the future.
If you decide to have surgery after discussions with your consultant, bear in mind that you might not be suitable for a partial knee replacement if:
- You don't have an intact anterior cruciate ligament (ACL). This is because there is a risk that, without a working ACL, the implanted components can fail. The reason for this is that the ACL ligament supports the knee joint. For the artificial joint to work optimally, the support of the ACL is necessary
- You have osteoarthritis in multiple compartments of the knee. A partial knee replacement is only suitable if one of your knee compartments is damaged. Patients with damage to two or all compartments will have better results following a total knee replacement
- You have a BMI greater than 40. If you’re classed as morbidly obese, you have a greater risk of infection and blood clots. There is also evidence to suggest that those with higher BMIs have worse outcomes and longer recovery times than those who maintain a healthy weight
- You have marked stiffness in the knee or a significant angular deformity. This is because these conditions are caused by ligament weakness, which means the soft tissue surrounding the knee might not be strong enough to support the prosthesis
- You have rheumatoid arthritis. As inflammatory arthritis usually affects the whole knee joint, most people with RA aren’t suited to a partial knee replacement.
In these cases, you may be recommended a total knee replacement as the most effective solution. However, each patient is looked at on a case-by-case basis, so your consultant will be able to tell you whether a partial knee replacement is the best option for you.
Why might I need a partial knee replacement?
Your consultant may recommend partial knee replacement surgery if:
- Your knee pain is keeping you awake at night
- You're struggling to walk because of knee pain
- Your knee pain is persistent and hasn't responded to other treatments
As well as being used to treat arthritis, a partial knee replacement can treat other conditions such as haemophilia and gout.
How to book an appointment with one of our knee consultants
To book an appointment with one of our leading knee consultants, simply:
- Call us today or use the find a consultant button below
- If you've been to see your GP about your knee pain, please have your referral letter to hand. It'll help us speed up the booking process
- We'll usually be able to confirm your appointment immediately. If not, your appointment will be confirmed within 24 hours.
What non-surgical options are available to treat my knee arthritis?
As a partial knee replacement is a major surgery, your consultant will suggest other, less invasive treatments first. These may include:
- Maintaining a healthy weight: Being overweight increases the pressure going through the knee joint. If you’re overweight and suffering from knee arthritis, losing weight could significantly reduce your knee pain and osteoarthritis symptoms
- Anti-inflammatory injections: Corticosteroid injections help to reduce inflammation in the muscles. This can significantly improve pain for patients with osteoarthritis or rheumatoid arthritis
- Physiotherapy: Rehabilitative physiotherapy programmes work to strengthen the muscles and soft tissue around the knee joint. By improving your strength and flexibility, you can take the excessive strain off the knee joint
- Pain medications: Over-the-counter pain relief like ibuprofen or acetaminophen can be used to treat knee pain. If these aren’t having the desired effect, your consultant can recommend other prescription medications (such as biological response modifiers or antirheumatic drugs) to minimise pain.
Partial knee replacement FAQs
Following your diagnosis, a consultant will explain the procedure to you in full, including any possible risks and side effects. They’ll be happy to answer any questions you may have about the surgery.
Partial knee replacement surgery is usually carried out under general anaesthetic but it can be performed with a local anaesthetic such as an epidural. Your consultant will discuss with you what the best approach will be, and you'll need to let them know about any medication you're on. If you’re having general anaesthetic, you’ll also be advised on how long you should avoid eating and drinking before your operation.
In the lead-up to your surgery, it's best to:
- Stop smoking several weeks before the operation
- Maintain a healthy body weight
- Keep up with regular exercise
- Stop shaving or waxing near your knee
- Have a shower or bath the day before the operation
Before you go into surgery, your consultant might provide you with antibiotics to take. These help minimise your risk of infection while in theatre.
During your partial knee replacement, your surgeon will first remove the damaged bone and cartilage in the knee compartment that they’re replacing. Once these have been removed and the worn bone has been resurfaced, your surgeon will replace the damaged cartilage with implants made of metal, plastic or ceramic. These are usually cemented in but non-cemented knee replacement implants are occasionally used. Once the prosthesis is in place, your surgeon will insert a plastic spacer. This mimics your cartilage, providing a smooth cushion for your knee. The surgery is usually performed using small incisions, meaning you'll recover more quickly than with a total knee replacement.
Due to our investment in the latest medical technology, your surgery may be conducted with the assistance of the Mako robotic technology. This allows for more accurate placement of implants, resulting in the knee joint feeling more natural following surgery. It can also cause less pain and give you a faster recovery time.
After surgery, you'll be taken to a room where you'll gradually wake up. Our nurses will be there to look after you and ensure you feel comfortable. Once you're awake, they'll take your blood pressure and pulse before checking your dressing.
Once the nurses have done their post-operation checks, they'll take you to your room to rest. Most patients will be able to go home on the same day as their surgery but your care team will be able to let you know whether they need you to stay in the hospital overnight.
The operation usually lasts between one and two hours. The exact length of the procedure depends on how much of the joint the surgeon has to replace. You’ll typically spend one to two days in hospital afterwards to monitor your condition and begin your recovery.
You won't experience any pain during the surgery itself because you’ll be under anaesthetic. You’ll be able to walk quite soon after the procedure but you’ll typically experience some short-term pain doing so. Your knee might feel a bit stiff and you might have trouble bending it. Your doctor may prescribe medication to control the pain. This usually takes the form of local anaesthetic and anti-inflammatory medication.
Whether a partial knee replacement will be effective for you depends on the condition of your knee, your age and your weight. If your arthritis only affects one compartment of the knee joint, a partial knee replacement could be beneficial. One of the main advantages of a partial knee replacement is that it preserves the healthy bone and ligaments. This means it involves less surgery and less trauma to the knee, usually resulting in a quicker recovery.
Your knee specialist will discuss all your options with you as part of your personalised care plan.
You can expect to go home within one to two days. After your surgery, a member of our physiotherapy team will help you get moving with the assistance of crutches or a walker. They’ll be able to give you advice on the best post-operative rehab exercises to do at home to support your recovery.
Our physios will also let you know how much weight you’ll be able to bear in the early stages of your rehab from your partial knee replacement. Most patients can walk without the aid of crutches or a walker after one to two weeks.
Your consultant will sit down with you after your operation to let you know when you can get back to your usual routine, including work or exercise. This is usually six weeks after surgery.
To help speed up the recovery process, your consultant might recommend the following:
- Icing the knee: Applying an ice pack to your knee several times per day in 20-minute bursts will help minimise pain and swelling
- Elevate your knee: Elevating the knee will help reduce blood flow to the knee. This can provide relief from inflammation, pain and swelling. When elevating your knee, it’s recommended to keep it above the level of your heart. You can do this by propping your knee on cushions while lying down or resting your leg on a footstool
- Keep your incision sites clean: Carefully follow your surgeon’s advice. They’ll tell you how often to change the dressing and when you can shower again
- Physiotherapy: Your care team includes a dedicated physiotherapist. They’ll help you move safely and aid recovery with a combination of massage and exercise
- At-home exercises: You’ll be given some simple exercises to do at home to strengthen the muscles around your knee, get blood to the area for recovery and minimise joint stiffness. You should be able to do these exercises almost immediately after your surgery.
You'll need to wait around six to eight weeks after surgery before you can drive again. You'll need to be able to sit comfortably and operate all pedals effectively. This means you'll need to arrange for someone to pick you up from the hospital when you're ready to go home.
Speak with your consultant when you think you're ready to start driving again after your partial knee replacement. If you're still unable to drive three months after your operation, you need to notify the DVLA.
How quickly you return to sports or high-impact exercise depends on the complexity of your operation and how well you recover. Your consultant will let you know when they think you are ready, but it's usually only once you've regained flexibility, strength and fitness post-operation.
Low-impact sports like walking, cycling, swimming and golf are typically possible earlier than high-impact sports like running, football, skiing and tennis.
Partial knee replacement longevity has improved as implants have advanced. Most people can now expect their artificial implant to last for up to 20 years, after which you may need knee revision surgery to replace the implant. The more revisions you have, the more likely you are to lose the bone from around the knee, which can lead to complications.
Why choose HCA UK?
Fast access to quality care: We'll confirm your appointment with one of our knee specialists within 24 hours. We can also provide imaging on the same day as your appointment if needed
State-of-the-art imaging facilities: We offer the full range of orthopaedic imaging services to accurately diagnose the source of your knee pain. Your consultant can then propose the most effective treatment
Top rated: We're number one in London for private orthopaedic care based on figures from the Private Healthcare Information Network (PHIN)
We're trusted: 99% of our orthopaedic patients would recommend HCA UK to their family and friends
Leading medical facilities: Our commitment to the best standard of care means we have the highest proportion of 'Outstanding' ratings of any private hospital group in the UK by the Care Quality Commission.
How much does a private partial knee replacement cost?
We offer self-pay patients fixed price packages for knee replacement procedures, for that extra peace of mind. Your consultant will advise you if one of the packages is suitable for your course of treatment, once you've had your initial consultation and any diagnostic scans have been reviewed. If you're eligible, there will be two options to choose from. We offer fixed price packages for both partial and total knee replacement surgery.
The package cost for the knee replacement procedure are confirmed beforehand to give you the reassurance of knowing the costs that are covered. Here’s a list of the costs covered by the package:
- Standard prothesis
- Nurse-led pre assessment
- Medication
- Hospital accommodation (incl. meals)
- Inpatient nursing care
- Inpatient physiotherapy
Speak with your consultant who will confirm if a fixed price package is suitable for your treatment.
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This content is intended for general information only and does not replace the need for personal advice from a qualified health professional.