For several decades in orthopedic care, the traditional solution to meniscus tears has been to identify them on an MRI and cut out the offending piece. While there’s little doubt that meniscus degeneration is at play in the cascade of knee arthritis, how all of this works is not so well understood. Now, a new study continues to point in the direction that meniscus surgery is likely the exact opposite of what we should be doing to help middle-aged patients with knee pain.
What is the Meniscus?
The meniscus is a spacer that helps to cushion the knee cartilage. This structure can get normal tears as we age, much like your face naturally wrinkles over time. While a huge industry has emerged around removing parts of the meniscus when tears are seen on an MRI, there’s little hard scientific evidence that this is a good idea.
· Trial after trial and “best evidence” has found knee arthroscopy to be ineffective for osteoarthritis and degenerative meniscal tears, and some surgeons refuse to do it
· Studies show no difference in pain and function over two years between arthroscopy and placebo
· In their own profession, orthopaedic surgeons recognise that many doctors are doing what has always traditionally been done and relying more on their own personal experience than on evidence provided by placebo controlled trials
· Research shows 20-50% of people over 50 have a torn meniscus, though most don’t require intervention
· While the benefits of knee arthroscopy appear minimal, orthopaedic surgeons warn that the risks of knee surgery are outweighed by potential harms including DVT, VTE, pulmonary embolism (blood clots on the lung) and infection
· Major international guidelines, including those from the Australian Orthopaedic Association, advise against arthroscopic debridement and/or lavage for osteoarthritis. However, around 100,000 of these procedures are done annually, unnecessarily costing the healthcare system an estimated $500 million a year
Every year thousands of Australians with osteoarthritis still undergo a knee arthroscopy even though trial after trial has found it is ineffective and some surgeons refuse to do it.
The procedure is costly at $4000-$5000 a procedure and involves keyhole surgery where the orthopaedic surgeon uses a camera introduced through small ports to identify frayed meniscal cartilage and shave off the worn edges.
In 2012, Professor Ian Harris, orthopaedic surgeon, of the University of NSW’s faculty of medicine, in a review for the Medical Journal of Australia, wrote “It’s a waste of time and money,” “The use of arthroscopy for knee osteoarthritis has been allowed to continue, exposing patients to an intervention that is at best ineffective, and at worst, harmful,” Med J Aust 2012; 197 (7): 364-365. “The best evidence we have is that it’s just not effective, not only for arthritis but for any degenerative meniscus tears”
A 2002 randomised controlled trial published in the prestigious New England Journal of Medicine found no difference in pain and function over two years between arthroscopy and placebo surgery in 180 patients with osteoarthritis.
A 2007 retrospective, evidence-based review of the current literature yielding 18 relevant studies, found limited evidence-based research to support the use of arthroscopy as a treatment method for osteoarthritis of the knee. The authors concluded that “Arthroscopic debridement of meniscus tears and knees with low-grade osteoarthritis may have some utility, but it should not be used as a routine treatment for all patients with knee osteoarthritis.”
Similarly, a 2008 trial published in the New England Journal of Medicine found no benefit between arthroscopy and placebo in terms of osteoarthritis pain, stiffness or physical function over placebo and medical and physical therapy, or medical and physical therapy alone.
The Cochrane group is a global independent network of researchers, professionals, patients, carers, and people interested in health, “gather and summarize the best evidence from research to help you make informed choices about treatment”. A 2009 Cochrane review shows that in people with OA, arthroscopic debridement: “Probably does not improve pain or ability to function compared to placebo (sham surgery)”
Professor Harris and his colleagues at Liverpool, St George and Sutherland hospitals in south-west Sydney have stopped performing the procedure on patients aged over 50. However they observe that it is entrenched among most orthopaedic surgeons across Australia. More than 50,000 Australians of all ages had a knee arthroscopy in 2011/2012 according to MBS data, up from 29,000 in 1999/2000.
In an interview with Australian medical magazine Australian Doctor Professor Harris said a large proportion would have been over 50. “It’s very difficult to change practice. [Doctors are] doing what has always traditionally been done and relying more on their own personal experience than on evidence provided by placebo controlled trials,” Professor Harris said.
“The truth is it’s easy to justify an arthroscopy for any patient who has a sore knee and a meniscus tear.” But the risk of over-treatment is immense with research showing 20-50% of people over 50 have a torn meniscus, though most don’t require intervention, he said. While the benefits appear minimal, orthopaedic surgeons warn that the risks of knee surgery are outweighed by potential harms including DVT, VTE, pulmonary embolism (blood clots on the lung) and infection,
Most recently, a meta-analysis of nine randomised trials published on 16 June 2015 in The British Medical Journal (BMJ)involving more than 1200 middle-aged and older patients with meniscal tears and/or osteoarthritis has found that arthroscopic surgery has a small but significant effect on pain that gradually disappears over one year. The analysis showed pain relief lasts only 1—2 years, comparable to paracetamol, less effective than NSAIDs and of “markedly smaller” benefit than exercise therapy. Arthroscopy in these patients results in only small improvements for pain, no benefit in physical function and carries the potential for harm.
The procedure is associated with six cases of VTE, four cases of symptomatic DVT, two cases of infection, one case of pulmonary embolism and one case of death per 1000 surgeries, according to the Danish and Swedish authors.
In an accompanying editorial Professor Andy Carr, an orthopaedic surgeon and director of the National Institute for Health Research musculoskeletal biomedical research unit at the University of Oxford, wrote, “Supporting or justifying a procedure with the potential for serious harm, even if this is rare, is difficult when that procedure offers patients no more benefit than a placebo,”
The authors of the BMJ study suggest that the demand for arthroscopy is driven by the results of knee MRI scans, even though incidental findings of “degenerative” lesions are also common among people without knee symptoms or osteoarthritis.
Melbourne rheumatologist Professor Rachelle Buchbinder agreed, telling Australian Doctor news journal, “There are some indications for arthroscopic knee surgery, but in people over the age of 40 with knee pain, osteoarthritis or degenerative meniscal tears, the majority [of surgeries] are unnecessary and probably causing more harm than good”.
Major international guidelines, including those from the Australian Orthopaedic Association, advise against arthroscopic debridement and/or lavage for osteoarthritis. However, around 100,000 of these procedures are done annually, unnecessarily costing the healthcare system an estimated $500 million a year, according to estimates from Professor Hunter and colleagues at the university’s Institute of Bone and Joint Research.