There are many factors that govern the success of a knee replacement procedure, one of which is the design of the implant itself. Traditional knee replacement technology offers a limited range of sizes, all of essentially the same shape, and this means that surgeons often have to compromise on implant fit, rotation and alignment. Your anatomy is unique. To achieve a perfect fit requires that the implant is personalized specifically for your knee.
Clinical studies have shown that traditional knee implants do not move in a normal manner during routine activities and rarely ‘feel normal’ to the patient. This could partly explain why 20-30% of knee patients report dissatisfaction.
So what makes a Conformis knee different?
Using data collected from a CT scan of your knee, Conformis manufacture a bespoke knee implant to exactly match your anatomy. To enable the surgeon to place the implant precisely a 3-D printed, single-use patient specific instrument set is also manufactured. Your bespoke knee is normally delivered to your hospital, ready for surgery, just 6 weeks after your CT scan has been received by Conformis. In contrast, a traditional knee replacement will be a size taken from the shelf that is the closest match.
So what evidence is there to show a Conformis knee improves patient outcomes?
There are a number of recent studies that show Conformis implants move in a similar manner to a normal knee (Zeller et al), with mid-term survivorship matching or beating that of traditional implants (National Joint Registry). Studies have also suggested a higher patient satisfaction rate following surgery.
For example, a clinical research paper published in The Journal of Bone and Joint Surgery in July 2020, found that out of 93 patients who had a Conformis iTotal knee replacement:
- 90% were satisfied, or very satisfied 1.9 years after surgery
- 88% reported their knee as feeling normal most or all of the time
- Implant survivorship was found to be 100% at an average of 23 months post-op
What about longer term implant survivorship?
The ‘National Joint Registry’ is a UK organisation that collects information on all knee replacement operations to improve clinical standards and benefit patients. It is a record of how well implants are ‘surviving’, or lasting in patients. So far at 6 years, Conformis has a cumulative revision rate (failed implant) of 1.7%. This compares to the national average of 2.5%.
The Orthopaedic Data Evaluation Panel (ODEP) is an independent panel of experts comprising mostly of leading UK surgeons. ODEP have awarded the Conformis iTotal with a 5A rating. This means that based on past performance and current scientific literature, there is at least 5 years of strong evidence that the implant performs as intended. Whilst the results so far are very encouraging, what is not yet available is meaningful long-term data (7 years plus), as the implant has only been available since 2011.
A bespoke implant is more expensive than a traditional implant but all major private health insurance companies usually approve Conformis procedures that are performed by surgeons trained in the Conformis technique. You can learn more about Conformis by visiting www.conformis.co.uk.