The Great Debate 2015

Review

Generics, Registries and Surgeon Choice

The hot topics at this years Great Debate were more political than ever, with three issues recurring through the meeting:

• How do conclusions from registries impact on your decision making?
• What should drive surgeon choice of procedure and implant?
• How should we as a profession compare generic vs branded devices?

Following a combined meeting with EFORT in Docklands last year, the 2015 Debate returned up river to the Mermaid Conference Centre.., where four brief presentations act as the catalyst for 35 minutes of debate, drawing in presenters, faculty, and delegates, who used Twitter and 2poll to let the faculty know where they stood. Under direct questioning, experts have to admit whether they practice what they preach. This year, Ashley Blom won over the audience by admitting that he only uses cement half the time on the acetabular side, despite giving a registry focused tour de force in favour of cement for everyone and everything.

Day one belonged to the knee. The audience involved itself from the start, using a mobile friendly web-tool to vote on upcoming points of discussion - which provided a useful barometer for the faculty; to be forewarned is to be forearmed. Simultaneously, the Twitter feed sprang into life, and provided direct contact between audience and chairmen. The first session focussed on TKR prosthesis design, with Jan Victor (Ghent, Belgium) in the PCL retaining corner, Tom Schmalzried (Los Angeles, USA) in the posterior stabilised corner, and William Walter (Sydney, Australia) contending that a medial pivot design was ready for prime time. Adolph Lombardi (Ohio, USA) admitted a direct conflict of interest when reporting on the bi-cruciate retaining TKR. Preliminary results of his multicentre trial suggested no better or worse than patients with a CR knee design at this early stage of the trial, while the superior AP stability of the medial pivot was convincingly demonstrated using delegate rated videos of Lachman and anterior drawer tests. This prompted a discussion about the limitations of PROMs to detect differences between implants and techniques and a consensus demand for more sensitive patient specific outcome measures, as well as greater emphasis upon objective measures of outcome, such as gait analysis.  

Next up was surgical technology and planning. Using the 2poll system, almost 90% of those voting saw no future for robotics in arthroplasty. This set the scene for Jan Victor who predicted that a new generation of user-friendly software, increasingly compact equipment, and an intuitive workflow, will lead to a renaissance in the use of navigation, but not robotics. Dr. Lombardi then made a persuasive argument for using PSI instead, which in his hands improved alignment, and enhanced operating room efficiency. Wolfgang Fitz (Boston, USA) contended that efforts to improve prosthesis alignment alone have been superceded by custom implants based on patients’ native anatomy. It is a truism that technological advances designed to help surgeons execute a pre-op plan will be limited by the quality of the plan itself. In this context Robert Barrack (St Louis, USA) argued persuasively for a more physiological alignment of TKRs, cutting the tibia in three degrees of varus. But Adoplph Lombardi and Jan Victor both felt that a human eye can more easily judge 90 degrees to the vertical than it can 87 degrees. So arguably, unless technology is being used to guide bone cuts, a 90 degree cut combined with a lateral to medial sloped polyethylene insert, as used by Prof. Victor, may be a safer option.

Topics discussed

New device designs

In the world of knee surgery, the shortcomings of the current generation of knee replacements are recognized by industry and surgeons alike. Several quite different knee designs have recently been developed and are being actively promoted. The size and maturity of this market makes it hard for a new product to make waves. 

Kinematics

Improvements in kinematics, with resulting increases in patient satisfaction are being strongly promoted. Do the improvements in kinematics make a difference and are the enhancements big enough to make surgeons change their minds? We shall see. 

Cruciate ligaments: spare them or substitute?

Ligament function and knee arthroplasty remains a big topic: should surgeons save the PCL, or ACL or both? Will device design supplant the need for cruciates, or should implants allow both cruciates to be preserved at arthroplasty. These two opposing strategies and the clinical evidence presented by their champions need exploring.

Joint line obliquity

This is a further dimension on most surgeons’ agenda and there are many unanswered questions. Is there a real advantage to a varus joint line or should every patient have a horizontal joint line as dogma has dictated for two decades? How do modern devices and instrumentation sets manage joint alignment? Is there any clear guidance from experts on exactly what surgeons should be aiming at? Does anyone know whether he or she can get it right first time? More questions than answers here, so a promising field for debate.

Hip implant choice

On the positive side, the success rates for hip arthroplasty seemed to improve, as the whirlwind of metal ions finally dies down. Many surgeons and even entire hospitals are being driven by financial imperatives and dicta that mean specialists have to repeat the mistakes of 30 years ago. The process for choosing implants needs to be discussed.

Resurfacing

Resurfacing still has a place in any debate, as registry studies continue to show. With 15 year data showing mortality and even revision rate is lower with resurfacing, is there a case for making this the only operation offered to men under 55 years?

Bearing choice

The bearing debate will reflect the problems in making choices that have to last for half a century, and the issues that face the patient, the surgeon and the hospital in making those choices. Who is in charge, and who should be?

Approaches

With the direct anterior allowing same day discharge, is there a case for more widespread adoption? Does a bikini incision offer a surgeon a real competitive advantage in a crowded marketplace?