Unicompartmental knee arthroplasty – also called partial knee replacement or minimally invasive partial knee replacement – is a surgical procedure used to treat isolated areas of severe knee arthritis.
Featured Image: Mako Robotic Arm for Knee Arthroplasty
Anatomy of the knee
The knee is made up of three compartments – the patellofemoral where the kneecap (patella) and thigh bone (femur) meet, the medial tibiofemoral which is on the inside of the knee and the lateral tibiofemoral which is on the outside.
Osteoarthritis, or wear and tear arthritis, can affect any compartment of the knee. Unicompartmental arthritis refers to disease in just one compartment of the knee. You will hear the terms bicompartmental for arthritis that affects two compartments and tricompartmental for the most serious form of the disease, affecting all three compartments of the knee.
What is unicompartmental knee arthroplasty
If only one compartment of your knee is affected by arthritis, you may be offered a partial knee replacement, rather than a total knee replacement.
This means that rather than removing the entire knee joint and replacing it with an artificial implant, only the affected compartment will be replaced.
The advantage of this is that more of your own tissue is retained, resulting in faster recovery from the operation, decreased pain and less blood loss. Retaining your internal knee ligaments (ACL and PCL) helps your knee move more freely as before, in a more natural manner.
Mako robotic arm assisted surgery: Benefits for unicompartmental knee arthroplasty
Arthroplasty is a surgical procedure to restore function to your damaged knee. Some leading edge orthopaedic surgeons like us have begun using a new approach to unicompartmental knee arthroplasty; using smaller incision surgery rather than a traditional open approach, with the adjunct use of Mako robotic assisted surgery.
This involves making a smaller incision of around 3 inches in the surface of the knee through which the joint is prepared and the artificial knee implant is inserted.
The smaller size of the incision means there is less damage to the muscles and tendons around the knee and recovery times are generally shorter.
Patients undergoing this procedure usually leave hospital after just one night stay and are normally able to walk unaided within one or two weeks of surgery. Blood loss is also less and there is less patient reported post-operative pain.
How do I know if I have unicompartmental osteoarthritis?
Osteoarthritis is a degenerative condition caused by the cartilage in your knee joint becoming worn. It produces a range of symptoms, which normally worsen as the disease develops. You may experience:
- Pain which feels worse when you move around or put weight on the affected joint. With severe arthritis, the pain may interfere with your normal day-to-day activities and can have a significant impact on your quality of life.
- Stiffness of the knee, particularly after a period of inactivity.
- Swelling or tenderness in the affected area.
- Crepitus which is cracking, popping or grating in the knee.
Until you undergo diagnostic imaging, it will be impossible to tell which parts of the knee are affected.
Related Reading: Tricompartmental Osteoarthritis – what it is and how it is treated
Diagnosis of unicompartmental osteoarthritis
After taking a full history, you will be given a physical examination to check for possible signs and symptoms of arthritis. If your doctor suspects you may have the disease you will be sent for an X-ray to check for signs of cartilage loss or bony growths, which can occur as arthritis develops.
In the majority of cases you will also have an MRI scan to check the condition of soft tissues in the knee joint. The diagnosis will reveal if you have unicompartmental, bicompartmental or tricompartmental arthritis, and importantly what treatment options are appropriate for you to consider.
Who is suitable for unicompartmental arthroplasty?
The procedure is normally offered to people with severe arthritis symptoms affecting one compartment of their knee. Not all surgeons offer this new minimally invasive robotic assisted approach but will offer a traditional partial knee replacement.
Alternatives to surgery
You will not normally be offered surgery until your symptoms are having a significant impact on your quality of life. This is because all surgery carries some risk and your surgeon will want to exhaust other treatment options initially.
Less invasive treatments may be recommended such as painkilling medication and anti-inflammatories, physiotherapy which can provide exercises to improve joint movement and flexibility, or injections (corticosteroids and hyaluronic acid) into the knee joint which may provide shorter-term pain relief.
If you are experiencing symptoms including knee pain, stiffness, swelling or crepitus, it is important to visit an orthopaedic consultant to obtain a proper diagnosis. Once the cause has been established and the severity of your symptoms ascertained, a treatment plan can be recommended.
Carrothers Orthopaedics Consultations – Cambridge
Carrothers Orthopaedics is currently open and scheduling clinic appointments, as well as surgery. The safety of patients and staff remains our number one priority at all times. We are happy to discuss fully the risks and benefits of any proposed orthopaedic surgery, in the context of the ongoing UK Covid-19 pandemic.
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For your convenience, we offer appointments at both Nuffield Hospital Cambridge and Spire Cambridge Lea Hospital.