Does knee surgery do more harm than good?
Middle aged and older people with persistent knee pain should avoid arthroscopic knee surgery, according to a new review published in the BMJ. The benefits of the procedure are said to be “inconsequential” and there are potential harms.
Knee arthroscopy increasingly used
Given the small benefit of surgery, and the potential for great harm, the authors concluded that their findings do not support the use of arthroscopic surgery for middle aged or older patients with knee pain, regardless of whether they haveosteoarthritis or not.
In an associated editorial, Professor Andy Carr, of the NIHR Oxford Musculoskeletal Biomedical Research Unit, suggested that a tipping point may soon be reached where the weight of evidence against arthroscopic knee surgery will overcome concerns about the quality of the studies and vested interests. When that point is reached, there could be a swift reversal of established practice.
Put to bed
In an email statement, Jane Tadman from Arthritis Research UK commented: “Arthroscopic surgery for people with knee osteoarthritis has long been discredited as an effective treatment by a series of research studies, yet it is still performed in the UK.
“Guidelines from the National Institute for Health and Clinical Excellence (NICE) make it clear that this procedure should only be used to treat knee osteoarthritis in patients with a history of their knee locking or giving way.
“Hopefully this new evidence from 9 trials will finally put the matter to bed. People with knee osteoarthritis would benefit more from exercising to strengthen the quadriceps muscle that supports the knee joint, and to lose weight if they are too heavy.”
Arthroscopic surgery, a type of keyhole surgery, is often used to remove torn cartilage and bits of loose debris from the knee, in the hope that pain and function will be improved.
Previous studies have shown that, although this type of surgery can relieve pain, the benefits aren’t long lasting and other treatments, such as exercise, have better results.
Despite the weak evidence, arthroscopic surgery is popular with many surgeons and is increasingly used to treat middle aged and older patients with persistent knee pain.
More than 150,000 knee arthroscopies are carried out in the UK each year on this group of people.
New review
Although other reviews have looked at the benefits of knee arthroscopy, none have looked at the harms as well. This review examined both.
The researchers trawled through 18 published studies and found 9 relevant, randomised controlled trials. Most of the trials were small and only two were blinded; that is, the patients didn’t know if they were getting the real treatment or a placebo (sham surgery). The other trials compared arthroscopic surgery with exercise.
There were 1,270 patients in total, and the average age of people in the trials ranged from 50 to 63 years old. All of the patients had knee pain and degenerative knee disease.
Those who were randomly assigned to have surgery, either had part of their damaged meniscus, which is the cushioning cartilage that separates the lower end of the femur (thigh bone) from the top of the tibia (shin bone) removed, or loose debris around the joint removed, or both.
The follow-up periods ranged from 3 to 24 months.
Some small benefit
The analysis of the 9 trials showed that surgery provided a statistically significant but small amount of pain relief at 3 and 6 months, compared with control treatments. The authors compared the pain relief as being on a par with that provided by paracetamol, but less than the pain relief provided by non-steroidal anti-inflammatory drugs ( NSAIDs), such as ibuprofen.
Also, the pain relief was short-lived and disappeared a year or two after follow-up.
The researchers also found that the procedure was not significantly better at improving the knee’s function, compared with the control treatment.
Harms
Only 2 of the randomised trials had adequately reported on adverse events, so the researchers supplemented these 2 studies with 7 observational studies to identify the potential harms of knee arthroscopy.
They found that for every 1,000 procedures there were about:
4 cases of deep venous thrombosis ( blood clot in one of the deep veins, often in the leg)
1 case of pulmonary embolism (blockage in a lung artery)
6 cases of venous thromboembolism (blood clot in a vein that travels to the lungs)
2 cases of infection
1 case of death
