I’ve been treating a chap with a sore knee who really wants to have an arthroscope (keyhole surgery). The knee’s been sore for a while. There’s some “degenerative changes” on a scan, including a torn meniscus. There’s a local knee surgeon who’s really good and is a friend of his. He thinks it’s a no-brainer. He needs an arthroscope. It a quick and easy solution to his problem that has worked well for him and his friends previously. It’s time to have “a bit of a tidy up”.
This is a very common presentation, and having an arthroscopic debridement is a very popular decision. 75,000 knee arthroscopies are performed in Australia each year. Therefore, you would imagine there is good evidence to support having one. Unfortunately it depends on who you speak to…
A change has been in the air since a 2002 randomised controlled study allocated 180 patients with osteoarthritis to either an arthroscopic “tidy up”, or sham surgery (where the patient was given an anaesthetic, incisions were made, but no actual “tidying up” was done) and the study concluded there was no meaningful difference in pain or function between the groups at follow up.
Since then, a number of studies have compared arthroscopic debridements and partial meniscectomy for degenerative knee injuries with exercise or doing nothing (Herrlin 2007, Kirkley 2008, Katz 2013, Sihvonen 2013, Yim 2013, Kise 2016) and the results have been unanimous.
A recent systematic review summarises: “these findings do not support the practise of arthroscopic surgery for middle aged or older patients with knee pain, with or without signs of osteoarthritis.”
And another: “A trial of nonoperative management should be the first-line treatment for such patients.”
Editorials summarise that:
“This high quality evidence dictates that meniscectomy is an ineffective treatment for symptomatic degenerative meniscal tears.”
“Arthroscopy for degenerative meniscal tears is no longer supported.” (ref)
“There is now overwhelming evidence that arthroscopic knee surgery offers little benefit for most patients with knee pain.” (ref)
SO WHY DID THE ARTHROSCOPE WORK FOR ME?
We do a lot of arthroscopes and people get better. What’s happening?
When you come and see me with degenerative knee pain and I tell you, “you need to do six weeks of strengthening exercises”, it sounds like hard work. Pffft. Understandably we want an easier option.
“Have surgery” sounds like an easier option. Someone else is doing the work for you. After the surgery, you proceed to do six weeks of strengthening exercises, but this time you’re happier to do the work because we take surgical post-op instructions seriously.
Six weeks later both these two groups are a lot better. Bingo-bango, “surgery” fixed me.
Two million knee arthroscopies a year globally, costing billions of dollars.
WHY DO PEOPLE HAVE SURGERY?
A pretty typical pathway goes something like:
I think we need to be careful at the MRI stage. MRIs are a lot cheaper and easier to get these days so it’s less of a big deal to get one. I was chatting to a mate with a sore knee and his MRI showed some degenerative changes. Rather than being told that it’s normal to see those sorts of things in knees as old as ours, and that it’s not necessarily the thing that’s giving him pain, he was told the knee is “bone on bone”. How can anyone ever expect to recover without surgery with that sort of imagery? Bone on bone seems definitive. Surely the only way to fix “bone on bone” is surgery?
But we know degenerative changes on MRI are poorly associated with symptoms, and degenerative changes are the norm in middle aged knees (ref).
Let’s try some strengthening. You will be surprised.
SO WHO SHOULD HAVE SURGERY ON THEIR CARTILAGE?
The people I do refer to a surgeon for cartilage surgery have suffered an acute twisting injury with mechanical “locking” symptoms (i.e., an inability to fully extend the painful knee because of a meniscus tear lodged between the articular surfaces).