If you are suffering from severe osteoarthritis of the knee, you may be eligible for knee replacement surgery. As orthopaedic surgeons, we perform both total knee replacements (also called total knee arthroplasty) and partial knee replacements (partial knee arthroplasty). But, what is the difference and how do you know which type of surgery is best for you?
Total or partial knee replacement?
The knee is made up of three compartments – the inside is called the medial compartment, the outside is the lateral compartment and the front is the patellofemoral compartment. In some people with osteoarthritis of the knee, only one compartment is affected, normally the medial compartment although sometimes it is the lateral compartment. In these cases, it may be possible to have a partial knee replacement to just replace the affected part of your knee. Partial knee replacements are generally offered to patients who have severe symptoms and lifestyle limitations from usually mid-stage osteoarthritis, before it has affected the other knee compartments.
The benefit of partial knee replacement is that more of the natural structure of your knee remains intact, including the anterior and posterior cruciate ligaments which are removed during a total knee replacement. Patients who have a partial knee replacement tend to have more ‘normal or natural’ feeling knee replacement movement and experience fewer complication and less blood loss. They may have a better range of motion in their knee post surgery and recover from surgery more quickly.
How long do partial knee implants last?
However, if you have a partial knee replacement you are more likely to need a repeat operation – called knee revision surgery – than if you have a total knee replacement.
According to Versus Arthritis, around one in 10 patients will need further surgery within 10 years.
By contrast, between 80 and 90% of total knee replacements will last around 20 years or longer. If you are overweight or involved in heavy manual work the chances of needing earlier than expected revision surgery increase.
What is Mako robotic arm assisted partial knee replacement surgery?
In some cases, the surgeon may use a new type of technology called Mako to assist with your partial knee replacement. Mako uses a state-of-the-art robotic arm to guide the surgeon, according to their pre-operative surgical plan, during the procedure.
Mako robotic arm assisted technology is used by the surgeon to create a personalised surgical plan, based on the unique anatomy of your knee. Prior to surgery, a CT scan is uploaded into the system which then produces a 3D model of your knee. This is used to plan your partial knee replacement in precise detail.
During surgery, the Mako robotic arm guides the surgeon, helping them to stay within the limits that were planned prior to surgery. This helps to ensure more accurate and hence generally less bone removal and more precise placement of the implant, at the same time protecting the soft tissues around the knee, all of which should result in better functioning of the knee over time.
Studies into Mako show that patients tend to have shorter hospital stays and less pain after surgery. Recovery times are also shorter.
Research into Mako partial knee replacements
But, how well do partial knee replacements last following Mako robotic arm assisted surgery? A study published in The Bone and Joint Journal in December 2019 looked at 1,018 partial knee replacements performed by surgery using the Mako system. Researchers wanted to evaluate how well robotic arm assisted partial knee replacements were performing at an average mid-point (five years post surgery).
They carried out a retrospective review of patients who had had surgery between June 2007 and August 2016. All patients were asked to complete a questionnaire detailing any revision surgery and outlining their level of satisfaction following their partial knee replacement.
The study showed that the implant was continuing to perform well in 97.8% of patients who had had a medial partial knee replacement, in 97.7% of those who’d had a patellofemoral knee replacement and in 93.3% of those who’d had bicompartmental knee replacement. Where there had been a need for revision surgery, it was typically because the implant had loosened or the remaining knee osteoarthritis had worsened. The vast majority of patients reported high satisfaction levels.
Partial knee replacement surgery | Cambridge
Carrothers Orthopaedics offers both Mako robotic arm assisted surgery (partial and total knee replacements) as well as patient specific implants or conventional knee replacement surgeries. Very few places in the UK currently offer the Mako approach and we are happy to explain the procedure to you and outline the benefits of the different types of knee replacement procedures.
Our consultation fees are clearly presented here.
For your convenience, we offer appointments at both Nuffield Hospital Cambridge and Spire Cambridge Lea Hospital.