When is the right time to have a knee replacement? Many patients worry that a knee replacement will wear out or fail within a few years and feel they should hang on as long as possible before having surgery. Certainly, patients should try all non-surgical interventions prior to proceeding with knee replacement. These include:
- Weight loss
- Exercise program
- Simple tablets such as paracetamol or anti-inflammatories
- Joint injections such as cortisone, hyaluronic acid, or platelet-rich plasma (PRP)
However, once quality of life starts to be affected despite these measures, then a knee replacement is a consideration. Patients who are severely affected by arthritis can experience:
- Significant pain with activity
- Stiffness after a period of inactivity
- Reduced ability to walk longer distances
- Poor sleep due to knee pain
- Deformity (bow legs or knock knees)
But what about age? Many patients in their 50’s and 60’s are cautious about knee replacement as there is a misunderstanding in the community that knee replacements only last 10 years. If we look at the Australian National Joint Replacement Registry (NJRR) data, which has tracked every knee replacement performed in Australia for the last 18 years, we see that the overall rate of knee replacement failure is only 8.4% at 17 years after implantation. That is to say, 92% of knee replacements will still be functioning in a patient 17 years after surgery.
Many patients are told to hold out for another year if possible. But will this make much of a difference to this failure rate? The NJRR data suggests this improvement is only minor.
According to this data, a patient who is 55 who waits a decade until they are 65 will have a 5% reduction in the likelihood that their knee replacement will last more than 17 years. During this time, presumably the patient has suffered significant pain and disability.
If quality of life is sufficiently diminished by knee pain from arthritis, younger patients may choose to accept this slightly higher risk of revision surgery in order to return to function and enjoy life sooner.
The Oxford Knee Score can help to quantify the severity of knee arthritis. It is a simple 12-question means of measurement of the pain and functional effects of knee arthritis. Patients scoring below 30 (out of 48) are potential candidates for successful knee replacement surgery.
Take the quiz below now!