Keyhole knee surgery is 'waste of time' review finds
"Keyhole knee surgery for arthritis pain 'is pointless'," the Daily Mail reports.
The headline is prompted by a review of the available evidence around knee arthroscopy (keyhole) procedures for people with degenerative knee conditions such as osteoarthritis – so called 'wear and tear arthritis'.
In spite of the headlines, this conclusion is not particularly newsworthy as it is consistent with current recommendations of UK guideline groups like the National Institute For Health and Care Excellence (NICE) and the British Orthopaedic Association.
One exception raised by the review is that knee arthroscopy is often performed, and recommended by these organisations, for people with mechanical locking or clicking symptoms, often consistent with meniscal tears (tears in wedges of cartilage in the knee joint). Based on the evidence from one key trial last year, the expert panel who did the review conclude there's no evidence for a benefit in these people either.
It remains to be seen whether recommendations in future updates of UK guidelines will alter as a result of these findings.
Where did the story come from?
The guidance was produced by researchers from various international institutions, including McMaster University and University of Toronto in Canada and South Western Sydney Clinical School in Australia. It received no sources of financial support and the authors declare no conflict of interest.
The Daily Mail coverage, while mainly accurate, may be a little misleading as it says these procedures are currently performed "on patients with a common form of arthritis" – implying osteoarthritis. This isn't strictly true as arthroscopy is not currently recommended for people with osteoarthritis; only if there are symptoms of locking.
What kind of research was this?
This was a clinical practice guideline on the role of arthroscopic (keyhole) surgery for degenerative arthritis and meniscal tears.
Degenerative knee arthritis can generally be thought of as osteoarthritis. It is a medical term used to describe people (usually older than 35) with knee pain who may have signs and symptoms of osteoarthritis or meniscal tears, such as locking or clicking.
The menisci are wedges of cartilage in the knee joint, in between the thigh and shin bones. The authors explain how a quarter of people over the age of 50 have some degree of degenerative knee disease.
In this guidance document, an expert panel reviewed current practice and looked at the evidence on knee arthroscopy. They discussed these findings – along with patients with first-hand experience of degenerative knee disease and its treatment – to form recommendations around the use of knee arthroscopy.
What do the group say about current practice?
The experts explain how the management of people with osteoarthritis (degenerative knee disease) often includes "watchful waiting" to see what happens, alongside exercise and weight loss (if overweight) and use of anti-inflammatory painkillers as needed.
More invasive treatment options that may be considered include steroid injections into the knee joint, arthroscopic knee surgery or knee replacement. There's no fixed consensus on what's best and management will often vary between patients.
However, keyhole approaches appear most common and more than 2 million procedures are performed worldwide each year, at a cost of $3bn per year in the US alone. They are particularly used when there are signs of meniscal tear.
What is the evidence for knee arthroscopy?
The experts considered available systematic reviews on knee arthroscopy. They considered pain, function and quality of life to be the most important and relevant outcomes for patients. In one review, though many of the 25 studies had looked at these outcomes, it was difficult to know what real-life meaning the changes would have (for example, a three-point change on a rating scale).
A key randomised controlled trial from last year found that knee arthroscopy was no better than exercise for people with degenerative knee arthritis with meniscal tear – yet this is often seen as a particular indication for this procedure.
The panel considered the quality and strength of the evidence using a recognised systematic approach (GRADE – Grading of Recommendations, Assessment, Development and Evaluations) to form their recommendations.
What does the group recommend about knee arthroscopy?
They strongly recommend against the use of arthroscopy in nearly all patients with degenerative knee disease based on systematic review evidence. They say that this recommendation applies to patients regardless of imaging evidence of osteoarthritis or the presence of mechanical locking or clicking symptoms (indicating meniscal tears).
The panel say they are confident that knee arthroscopy does not improve long term pain or function. They did find evidence that for a small number of people (less than 15%) arthroscopy gave small improvements in pain or function for a few months, but this wasn't sustained by one year.
They consider that the potential risks of the procedure outweigh any possible short-term benefit. Aside from rare complications, common drawbacks are that it can take weeks for people to fully recover from arthroscopy. Pain, swelling and difficulty putting weight on the leg are common.
Symptoms from degenerative knee conditions often fluctuate, and many can experience improvement over time without intervention.
The panel feel confident that further research is unlikely to alter this recommendation.
The only helpful use of arthroscopy is for people with a truly locked knee they can't straighten. The recommendations also aren't relevant to people with sports injuries or major trauma.
This expert panel review provides compelling evidence against the use of knee arthroscopy for degenerative knee conditions/osteoarthritis. This procedure often has varied and inconsistent use in clinical practice.
As part of their review the researchers also considered what other government organisations currently recommend about the procedure.
NICE already says knee arthroscopy (with washout – flushing the joint with fluid) should not be performed for people with osteoarthritis. The only indication NICE currently gives for the procedure is people who have a clear history of mechanical locking symptoms. But it's not clear whether the person has to have a truly locked knee, or locking and clicking symptoms that come and go.
The British Orthopaedic Society, like NICE, advises against arthroscopy for people with osteoarthritis but does recommend the procedure for people with mechanical locking symptoms. It also explicitly recommends arthroscopy with partial meniscal removal for people with meniscal tears.
Therefore, UK guidelines currently support the advice not to use the procedure for osteoarthritis, but do recommend it for locking/meniscal symptoms. It remains to be seen whether these expert panel findings alter recommendations in future updates of these guidelines.
Links To The Headlines
Links To Science
Siemieniuk RAC, Harris IA, Agoritisas T, et al, Arthroscopic surgery for degenerative knee arthritis and meniscal tears: a clinical practice guideline. BMJ. Published online May 10 2017