Ramsay Newsroom

Dr Christopher Vertullo, a specialist orthopaedic knee surgeon who operates at Pindara Private Hospital on the Gold Coast, has completed a PhD examining the “effects of surgeon preference-driven variation on outcomes in total knee replacement”.

Dr Vertullo’s thesis was the first paper to explore the motivations driving surgeons to prefer a particular total knee replacement (TKR) over the many others that are available.

“This is an important area to investigate given the increasing incidence of TKR worldwide and the burden of revision [redo surgery] due to early prosthesis failure,” Dr Vertullo said.

Decades of innovations in TKR design have led to a surprisingly large number of prostheses being used – more than 500 different types and brands in Australia.

He said surgeons tended to have a dominant preference for one type of implant over another due to a large variety of complex factors, against a background of a lack of consensus as to what constitutes practice-changing clinical evidence. These factors included surgeons having a strong desire for improved patient function, reproducibility of outcome and consistency.

“These factors can make it difficult for a surgeon who has a preference for one type of prosthesis over another to easily change that preference,” Dr Vertullo said.

Some TKR designs have higher risks of failure (also known as revision) than others.

The most common reasons for re-performing TKR surgery are loosening, infection, pain and instability.

Dr Vertullo said when surgeons currently examine the failure risk of their preferred prosthesis, they typically compare it to the average failure risk for all prostheses listed in the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR).

“This means a surgeon may understandably believe their preferred TKR is satisfactory, because they are comparing it to the average of all implants rather than the lowest risk options.”

Dr Vertullo suggested an alternative approach would be for surgeons to adopt an “Optimum Prosthesis Combination” (OPC) as the benchmark comparator – a TKR with the lowest risk of failure in each of the 5 categories of design.

Currently the OPC is a minimally stabilised, fixed bearing TKR with cemented or hybrid fixation, highly-crossed linked polyethylene and a resurfaced patella, with a failure rate of only 2.4% at 10 years compared to 5.5% for alternative designs options.

“This OPC concept has the long-term potential to aid surgeons’ clinical decision-making to reduce revision risk, improve patient outcomes, and reduce costs.”

Dr Vertullo said standardisation of care using evidence-based guidelines and decision tools is increasingly becoming essential to enhance health care value.

“As such, unwarranted prosthesis variations can be reduced,” he said.

Dr Vertullo said his research was also relevant to surgeons, patients and health care funders on a broader scale.

“While the findings and conclusions are directly applicable to knee arthroplasty surgery, the concepts are indirectly applicable to all forms of surgery where surgeons have preference for a variation of management.”