Osteotomy, knee replacement & the value of sharing ideas
This is a report back from a recent (Oct 2016) visit to the premier osteotomy centre in Europe (& possibly the world), where I was hosted by surgeons Philipp Lobenhoffer and Kristian Kley - good friends of mine and individuals that I have learned so much from over the last decade.
Kristian organised a really exceptional programme of cases with two double osteotomies, four distal femoral osteotomies and three high tibial osteotomies, and also some very interesting total knee replacement surgery. We had excellent discussions as always, and thought about innovations that we could introduce to make osteotomy more efficient and more safe and reproducible for other surgeons.
Take-home messages
Amongst the many things I learned, here are some of my 'take home' messages:
- The first take-home message was in knee replacement surgery. For many years I have been following the concepts of kinematic knee replacement surgery, in other words fitting the knee in accordance with the patient's own anatomy (and not just putting it in according to the average, which is how we had been doing it for many years).
We have been taking our jigs and pretty much setting the figures to the same for every single patient coming through, making the first cut at the end of the femur usually at 5 degrees of valgus (but of course many patients have got more or less valgus). We have been making the cut on the tibial side at 90 degrees to the floor, which isn't actually the way our anatomy is normally. In fact it is three degrees inclined from the inner aspect of the knee rising to the outer aspect of the knee.
So in Hannover for the last two years they have been doing kinematic knee replacements where they have been cutting the femur in valgus and the tibia in varus, and they say the results have been surprising in terms of the improvement. Maybe this is one of the reasons why in our practice we have this 20% failure rate in knee replacement - we are just doing the same to everyone where a more individualised approach would be more appropriate.
So this now something that I am certainly going to look at. I think it helps that we are all deformity surgeons and constantly looking at the anatomy of the limb and calculating angles by doing this, and we can apply this to our knee replacement surgery. It maybe isn't what I was expecting to walk away with but actually one of the biggest things that I will take home from Hannover is a change in technique for total knee replacement surgery. - Another thing that was an eye-opener for me that we will definitely be getting in is a pneumatic system for moving the leg during knee replacement surgery from extension into deep flexion. We currently rely on a system to do this and we only have two positions - cross bars for the feet to rest on - a little bit of flexion and then we can flex the knee up and rest the foot on another bar - but actually being able to dial in different levels of flexion was a very interesting thing to see. Actually Philipp Lobenhoffer said that, if on a desert island and there were only one or two bits of equipment you could take, this would be one that he would certainly be taking with him. It looked fantastic and is something again to hopefully introduce into my own practice in the UK.
- My third take-away relates to osteotomy. I have always used four K-wires to create my cage for closing the osteotomy - two high and two low. In Hannover they just use a single K-wire for each, and actually it makes it much easier in many ways. As long as you're careful about the saw-blade position I think you can be more accurate it is of course easier to perform and quicker. This is probably the most difficult part of a closing-wedge osteotomy - directing two K-wires to meet each other across a bone and doing it with two wires is half as difficult as doing it with four wires. So again a very simple but useful tip to have picked up and something that I will be taking back to our practice.
- Kristian Kley also demonstrated this very nice technique for feathering the bone with a saw near the end of the procedure when almost closed to get the final few millimetres of closure. It's something that I have seen in his lectures but really seeing it first hand makes all the difference. So again for something that I consider myself to be a real expert in it was interesting to see so many of these tips and pearls from a centre of excellence and to learn from their experience.
- Next we talked about the best place to actually start the osteotomy in terms of wire position on the femur, and I think a lower position does make more sense - something they have been doing in Hannover as the plate is gripping with the screws into the stronger bone distally. Also they have learned to bend the plate very slightly to improve its fit and this seems to work extremely well.
- It really helped - talking of planning - to sit down and go through their planning technique and compare it to my own, and it just reminded me of the importance of keeping to the rules that we have created - not cutting any corners - and probably going for double osteotomy rather than single osteotomy to make smaller corrections in both bones rather than a larger correction on a single bone to maintain a horizontal joint line. Currently we accept an MPTA (medial proximal tibial angle - which is the figure that we measure around the knee) - of 95 degrees - but probably we should reduce this to 93, and do more surgery in the femur as well as the tibia.
Adrian Wilson
This trip to Hannover was long overdue, and something that I really wanted to do for my own education.
What is always very humbling as a surgeon - and so important - is coming to a centre like this and seeing these two amazing surgeons in action together. It’s probably been the best educational trip that I’ve made since being a Consultant.
I travel a lot as a result of my educational activities, but usually I am doing the teaching - live demonstrations, and lectures. It’s not often that I can really immerse myself in someone else’s practice like I have here, and take home all these subtleties that they have developed to make osteotomy surgery even more straightforward than I have done already in my practice.
Kristian Kley & Adrian Wilson
I ‘scrubbed’ for all the cases and it has just been totally superb. I think that surgeons shouldn’t just get used to their own techniques and not look to improve and modify and incrementally change things to improve for themselves and for the sake of their patients.
Kinematic vs. mechanical alignment: What is the difference?
Discussion between Doug Jackson and Stephen Howell.
For any surgeons interested in the 2016 osteotomy masterclass at Basingstoke, UK....
