Mr. Haddad: Thanks again to Seth for a great meeting and the opportunity to reawaken European debate.
Now you all understand what brings this all about. The Germans have made a rule that we have to put hinges in everyone. And as a result of that, we being rational Brits, have worked out that that is not necessary and therefore we will exit Europe at any cost. (laughter)
The reality is that we are not radical. We are rational. Seth, I knew Thorsten would quote this paper and, of course, we use hinges, but we use hinges in selected patients where appropriate and because we’ve learned from Thorsten and others we can make them work extremely well.
Don’t get me wrong. Thorsten’s a charming, good-looking, impressive man. How many people have a gym in their office? There are women queuing up to have their picture taken with Thorsten. But there was a day when Thorsten realized that the knee is not a hinge. It has condyles. And you can balance it.
So, the principles of revision are straightforward. We definitely have to be surgically radical and there is no doubt the ENDO-Klinik led the way by being very aggressive and using hinge implants.
But the reality is that hinges don’t always go well, and the salvage is very difficult to come back from. We have a very established infection service doing a large number of single-stage revisions, but we use hinges less than 25% of the time. And we’re not crazy.
The reality is, it’s all about the debridement. And I have to keep telling Thorsten, debridement is not ablation. Looking at the MCL doesn’t mean you have to remove it. It’s nice to have a cancer analogy, but that principle is to debride what you need to debride and then let somebody else reconstruct and it doesn’t stop you from debriding too much. You must really debride well and try to preserve knee balance.
Because there are several phases to debridement and it’s not just a question of cutting everything that you can see. It’s surgical. It’s mechanical. It’s chemical. And there are other methods.
Of course, we expose, we explant, we excise the membrane very much as Thorsten showed you, and there are occasions when you just have to take it all out and some kind of hinge or tumor implant is needed. But if you correct and ream properly; if you use pulse lavage effectively; use hydrogen peroxide to really clean those surfaces and then add in chemical debridement, you’ve got every chance of retaining tissues that give you a knee that you can reconstruct.
We do this effectively and we try and retain some of the soft tissue envelope and preserve the collaterals so we can reconstruct a knee that looks like a knee replacement.
The other concern that people cite for using hinges is bony deficiency. We now have zonal fixation particularly with cones, which means we can reconstruct without having to go to a long-stemmed hinge. So, we’ve got different, varying, evolving forms of metaphyseal fixation that really allow us to take difficult situations and reconstruct without having to rely on long stems. Because a knee is not a hip and if you just use stems for fixation as we do the hinge, you will occasionally run into trouble.
So, we reconstruct rather than replacing. We try and fill the bone. Here’s a scenario where you might be really tempted to think that a hinge would work in an infected knee with a periprosthetic fracture, a collapsed tibia…all sorts of reasons just to bail out and do a radical solution.
But the reality is if you debride; if you clean, you can come back and then reconstruct the metaphysis and you can get to a stage where you can reconstruct with a stabilized condylar knee without necessarily having to apply a radical solution.
Some basic principles: preserve the epicondyles, where you can—of course, if they are infected you take them away. Cones to improve zone 2 fixation. Cemented stems with antibiotic-loaded cement. That way you get a better joint line restitution. We think we improve function. We avoid burning bridges. And I suspect in the long run, it’s cheaper.
Of course, we use hinges, but they are a salvage device. Because hinges have problems. It’s tough to control the patellofemoral joint and get tracking so we base our choice on collaterals and balancing rather than going to one solution for everybody. That probably gives us more options in terms of biomechanics and functions.
