The population is getting older and more active and more and more people are getting problems with their knees.
There are very good reasons to delay knee replacement in these young people, ans osteotomy has an important role to play here.
These days, lot of people now are having very serious problems with their knees at an early age, and it is not uncommon to meet someone in their mid-30s onwards with very serious problems in one compartment, perhaps more, within their knee. Usually this is someone who has been sporty and they have ruptured their ligaments and have soldiered on with an unstable knee, or perhaps they have had trauma in the form of a significant blow to the knee after a motor cycle injury.
So we have these real challenges now of a young patient with a very damaged knee compartment, and although there are a few proven surgical options available to us such as meniscal surgery, cartilage surgery and ligament surgery, dealing with the pain of arthritis for a young person is very difficult. Now knee replacement is a very good operation and partial knee replacement is also a very good operation, but once a patient "loses" their own knee joint there is no going back. I do a lot of partial knee replacements and my patients are happy but they carry all of the very serious risks that a knee replacement carries, and if they go wrong then you are into revision knee surgery territory.
The worst complication of a knee replacement is an infection. If the infection is deep, their partial or complete knee replacement needs to be removed, a temporary replacement put in and then after 6 weeks of antibiotics (to eradicate the infection) it may be safe for a new knee replacement to be put in. The sort of infection that we are talking about here usually has only an 85% clear-up rate so you are looking at 15% of patients where you won’t eradicate that infection, and in the ones that do successfully have their infection dealt with then those patients have got a revision knee which often does not work quite as well as the first time knee. So that’s one problem. The other problem is, even in the hands of very experienced knee surgeons, ten patients out of a 100 are going to come to the clinic and say “I am now much worse off than I was before you did my knee replacement”.
Dealing with an infected osteotomy is again not an easy problem but it’s completely different from dealing with an infected knee joint where you have limited choices, ie. whatever happens from that moment on that patient has to have an artificial knee. The difference with the osteotomy is that usually you can eradicate the infection by carrying out a surgical washout and debridement and if that doesn’t work well then we have several other options available to get the osteotomy site to heal up. The most common approach is just antibiotic suppression, ie. getting the infection under control with antibiotics until the osteotomy has healed, and when this happens the plate can be removed and the infection has gone. So although infection is a serious problem but it is much much more straightforward to deal with by a combination of surgery and antibiotics than the situation where you have replaced the whole of the knee. As an osteotomy is a completely extra-articular procedure (it is done outside of the knee joint), even if infection occurs the knee joint itself is not affected. Treating and eradicating infection in bone, or part of a bone, is much easier than treating infection inside an artificial knee joint.
You can’t usually salvage an infected knee replacement – once they are infected they usually need to be changed – but you can salvage an infected osteotomy and it might even mean that the patient has to spend a short time in plaster as you would do if you had a fracture but with appropriate surgery and antibiotics infection is not something that is that difficult to deal with. And it is very rare in both cases.
Modern day knee replacements are supposed to last you ten years at least, and when we say ten years actually 95% of knee replacements are actually functioning well at ten years, which means only 5% fail by the ten year mark. And now we’ve got very good data for 20 years, and the 20-year failure rate is around about 15%. So a well-positioned knee replacement in appropriate patients tends to do very well but really you have to have a sedentary lifestyle for a knee replacement to last a very long time. So if you are 65 and you don’t do that much and you are not that active, it is going to last you forever.
What we have found is with the young patients that are coming in with their arthritic knees, we are doing knee replacements at an earlier age and the results are much much worse in the 60 and under age group and very much in anyone under the age of 50. Now that doesn’t mean that we don’t do knee replacements in these patients (indeed, they are sometimes the only option), and it doesn’t mean that we don’t have success in this younger age group, but what follow-up studies have shown us is that the failure rate is much much higher in a young active patient versus that sedentary patient who is 65, because in the former group their pain goes and they want to be active again, and the knee replacement doesn’t cope with that terribly well.
So knee replacement survivorship in the young patient is not great, meaning you have three options:
If you take a total knee replacement, the advice most surgeons give to their patients is that "you may just get back to doubles tennis". And "you don’t want to be too active on it as it is designed for pain relief and to allow you to walk two or three miles and to go up and down a flight of stairs without pain", and "if you do too much with your total knee replacement the knee will swell and will cause you discomfort and it won’t last that long if you are very active on it". For a partial knee replacement we say to patients “You can be more active but again avoid impact” and patients frequently do get back to a week of skiing, a bit of windsurfing, golf is much more comfortable but then some feel so good they go on and do silly things like run and they shouldn’t.
Now with an osteotomy in some circumstances you are dealing with a different group of patients, because if you do your osteotomy for relatively early disease in the joint, before the horse has bolted, the patient usually does have a reasonably good knee. You have offloaded them, you have significantly reduced their pain and as the rest of the knee is not bad, they can get back to a lot more active lifestyle such as gentle impact activity. A few professional athletes get back to playing professional sport but generally speaking we are talking about someone like a farmer who wants to be active on the farm and go out every day and walk around and have a knee that works and he is not going to wear it out. And that is what osteotomy is going to allow someone with a physical lifestyle to do.
In terms of sport a lot of patients get back to a light degree of impact activity like jogging, and certainly cycling. With a knee replacement we used to say 90%, a bend of a right-angle, was success. We’ve moved on from there now. Now we say to patients, particularly to patients with a good range of movement before the surgery, we would like to get you to 125 degrees, which is only 10-15 degrees less than "normal". With an osteotomy if you have a normal range of movement before the surgery, you shouldn’t lose any of that movement. So you should have a normal range of movement in your knee after the surgery. Again, as the surgery is extra-articular, ie. doesn't involve the knee joint itself, the range of movement in your knee remains full. Often with an artificial knee joint you don’t get that. That is something that a lot of patients complain of following knee replacement surgery.