Knee Arthroscopy 2017 - the debate continues

Arthroscopy has been over-used by orthopaedic surgeons over the last 10-20 years.

First published in 2017, and reviewed August 2023 by Dr Sheila Strover (Clinical Editor)

Originally arthroscopy was our only means of really assessing the knee other than X-ray or CT-arthrogram. We did not have MRI 20-odd years ago, and so surgeons used to do arthroscopies to see what was going on. In fact they used to make a single portal and use that as a 'diagnostic arthroscopy'.

Quite rightly, over the last 10-15 years 'diagnostic' arthroscopy has completely died a death and we just don't do it - because it is very unusual if you can't put a clinical picture together based on the clinical history, the X-rays and the MRI scan.

But there is a debate going on about the eligibility of arthroscopic surgery in the management of the symptomatic older patient with evidence of degenerative changes in their knee, and who develops new mechanical symptoms because of something obstructing the joint.

The situation was brought to the fore after the public media reacted to this medical publication in the British Medical Journal in 2016 -

Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients: randomised controlled trial with two year follow-up. Kise NJ, Risberg MA, Stensrud S, Ranstam J, Engebretsen L, Roos EM. BMJ 2016;354:i3740. doi:10.1136/bmj.i3740 pmid:27440192.

You can read useful discussions here and here.

N.I.C.E. Guidelines

N.I.C.E. - the National Institute for Health and Care Excellence - publish guidelines that assist medical practitioners, hospital decision-makers and medical insurers to make decisions about the patients in their care. In their recommendations for "Osteoarthritis: Care and Management" they recommend that the practitioners "Do not refer for arthroscopic lavage and debridement as part of treatment for osteoarthritis, unless the person has knee osteoarthritis with a clear history of mechanical locking". [Lavage means 'washing out' and Debridement means 'removing unstable bits of material'.]

What is 'mechanical locking?'

What is meant by this term is the sudden alteration in the range-of-motion of the knee with the patient unable to fully straighten the knee. This implies that something has jammed the joint - and the common example is that of a bucket-handle tear of the meniscus.

Symptoms of mechanical interference short of locking including catching and giving way, and these may be attributed to flap tears of the meniscus or the joint cartilage, or loose bits of meniscus or cartilage floating free in the joint cavity as 'loose bodies'.

When things get unclear

Now in my experience it sometimes it really is equivocal what's going on - there may be nothing on the MRI scan that you can see and yet arthroscopy reveals a large piece of loose meniscus or loose joint surface that just wasn't picked up on the scan. So in my opinion when there is persisting pain (where non-surgical interventions been tried and failed) - and there are mechanical symptoms -  it really makes sense to do an arthroscopy.

A lot of people in their 40s and 50s present with degenerative meniscal tears and they come in to see me - they can't do their sport, often they have night symptoms, catching and locking and so on - in these patients a meniscectomy can be life-changing. I was chatting to one of the fathers at the cricket last night - very fit, teaches cricket, plays cricket he is 52 he had an arthroscopy a few weeks ago and was amazed that he suddenly he had no pain and that searing stabbing pain that he was getting medially was all gone because his meniscus flap was removed. A recent patient was another good candidate for arthroscopy because he had a clear flap on his scan and removing that flap was important for the relief of symptoms, and in his case microfracture of the bar bone exposed when the flap was gone was totally appropriate. In fact his microfracture is in exactly the right spot to get the best result from microfracture - so he should do very well.

But what we have been forced to do by all the insurance companies is make sure that we take our time to get to arthroscopy.

And it is really often a 'box-ticking' exercise where we send them off for physio for 6 weeks, we give them an injection and see if they settle - and some do. But in my opinion the ones with the mechanical symptoms where you either suspect there's a flap or loose body or something that's catching and you can often see that type of tear on MRI scan these should have an arthroscopy as soon as possible to remove that piece of torn, frayed meniscus that is catching, such that they can get on with their life.

The symptomatic 'degenerate' knee

Now if you have someone who is in their late 50s with a very degenerate knee and there are no 'mechanical' symptoms - just a vague aching or pain - and they have early or severe arthritis - arthroscopy doesn't tend to help much. In fact it is a bit 50:50, and if it does help often it is only for a few weeks.

Now the difficulty is, if the next step is some form of knee replacement, and you don't have 'bone-on-bone',  then we as orthopaedic surgeons would go for the arthroscopy, even if it made the patient slightly worse and they did not get any benefit and the next step was a knee replacement. Because a knee replacement is a completely different operation to an arthroscopy.

Where arthroscopy is REALLY being abused is where people are bone-on-bone - full thickness joint surface disease - and surgeons are doing arthroscopies to 'tidy up their joint surfaces'. This is a complete waste of time - and that is being done by the bucketload around the world, and that is why we have got such a bad reputation for arthroscopy because so many degenerate knees are bing 'washed out', and it is the washout that really shouldn't be done. As a result of the washout issue the insurance companies are now monitoring what we surgeons are doing for anyone over I think the age of 45, and our conversion rate to arthroscopy. And if they feel that you are doing too many arthroscopies - irrespective of how fit and active the patient is (they can be biologically 25 or 30 and doing marathons) - if they are over the age of 45 the surgeon gets a black mark if he does an arthroscopy.

So you have to be very careful that you prove to the insurance companies that you are not some gung-ho surgeon that is just washing out loads of knees for wear-and-tear arthritis and that you are only doing the appropriate ones. And you do that by physio, injection, MRI scan, try and settle them down, and if they don't then you do an arthroscopy - it often delays surgery by a good couple of months and that sadly is the way it has gone. So there is some bad press about arthroscopy - it is based around the results of washout surgery for Grade IV arthritis and in that instance arthroscopy is NOT appropriate. It may be appropriate as a planning tool if you are considering an osteotomy or a partial knee replacement if you want to assess the knee and see if the patient is suitable for some form of knee preserving surgery, but 9 times out of 10 you can make that assessment without the arthroscopy. So what we really need to stop is the washout surgery, but where people have loose flaps of cartilage or meniscal tears that is where arthroscopy can be very useful.