(03) 6214-3060Unicompartmental knee replacement is a type of partial knee replacement where just one of the two tibiofemoral compartments is replaced – usually the medial compartment (inside of the knee).
A unicompartmental knee replacement is a smaller operation than a total knee replacement with less pain, less blood loss and a faster recovery. Patients are usually on their feet walking the next day and stay in hospital for 2 to 4 days.
Unicompartmental knee replacement is only appropriate when the arthritis is isolated to one compartment of the knee. If your pain is isolated to the inside aspect of your knee then you may be suitable. Age, gender, activity levels and body mass are also a consideration.
Superior functional results are achieved after unicompartmental compared to total knee replacement. People with unicompartmental knee replacements generally have a more “normal” feeling knee and recover more rapidly compared to a total knee replacement. However, unicompartmental knee replacement carries a greater risk of revision surgery compared to total knee replacement. According to the Australian Joint Replacement Registry revision surgery is most commonly required for loosening of the implants or progression of arthritis to involve other areas of the knee. The Australian registry shows 79% of all unicompartmental knees last at least 15 years. For young patients (aged < 55) the 15 year survivorship is 67.5%. If revision surgery is required it is generally easier to revise a unicompartmental knee to a total knee than it is to revise a primary total knee replacement to another total knee replacement.
As with total knee replacement one of the most crucial aspects to ensure a good result with longevity is to correctly size and align the partial knee replacement. This helps to avoid early loosening, wear and ultimately failure – with subsequent revision to a full knee replacement. To achieve correct fit and alignment I use patient specific cutting guides which are produced based on precise measurements from a MRI scan and are then 3D printed to fit each patient’s unique anatomy. Patient specific guides have been shown to be more accurate than traditional “eyeballing” guides. Please see this video for a full explaination of this procedure and technology
