A common knee surgery — the partial removal of meniscus cartilage — may provide little benefit to people with knee osteoarthritis and may actually worsen their prospects for long-term knee health, according to new research from Finland, whose findings are reported in a correspondence paper published in The New England Journal of Medicine.
Study participants who underwent surgeries to remove torn parts of meniscus cartilage in their knees faired more poorly over the next 10 years than those who had undergone sham surgeries in which no cartilage was removed.
People who received the sham surgery had less knee pain, had increased use of the knee, and experienced less later osteoarthritis compared to those who had had meniscectomies.
The meniscus is a piece of tough, C-shaped rubbery cartilage in the knee that provides shock absorption between the shin bone and the thigh bone. It can tear as the result of a sudden twist.
More commonly, however, tears occur with age, and commonly go hand-in-hand with osteoarthritis. Most older people who have arthritis in the knee also have meniscus tears, and most older people with meniscus tears have arthritis.
For many years, it was assumed that meniscus tears were the source of knee pain.
Cedars-Sinai LA orthopedic surgeon and sports medicine specialist Clint Soppe, MD, who was not involved in the recent research, told Medical News Today: ”I remember 20 years ago, 15 years ago, hearing doctors, some of my mentors, say like, ‘Oh, well, you know, that’s not arthritic pain. That’s meniscus pain.’ The problem is you can’t tell.”
The study’s senior investigator, Teppo L.N. Järvinen, MD, PhD, of the University of Helsinki, however, told us that: “There is now a substantial body of evidence suggesting that we may have been targeting the wrong problem. The meniscal tear is often a visible finding, but does not seem to be the (sole) cause of pain — at best.”
“In middle-aged and older individuals, meniscal tears are extremely common, including in people with no symptoms,” Järvinen added. “That makes it unlikely that the tear itself is usually the main driver of pain.”
“This study fits into a pattern seen across medicine: Widely used treatments can persist despite limited evidence, and when tested rigorously, may turn out to offer little benefit — or even cause harm.”
– Teppo L.N. Järvinen, MD, PhD
Paul Arciero, DPE, of the Health and Human Physiological Sciences Department at Skidmore College, who was not involved in the recent research, agreed, saying that: “Anecdotally, most individuals, both active and sedentary, who have undergone arthroscopic partial meniscectomy report worsening of their pain and mobility over time.”
In relation to this, Soppe cited the advances in our understanding of chronic pain conditions over the past few decades.
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According to him, “all these different cell mediators that we didn’t know about or know much about 20, 30 years ago — interleukin inhibitors, cytokines, enzymes, TNF-alpha, metalloprotein — all these things that we know are associated with pain, and probably associated with meniscus-type pain.”
“I think one of the most important measures is giving [knee pain] time,” said Soppe.
During that waiting period, he recommended “helping with symptoms using different modalities: anti-inflammatory pills, physical therapy, icing, [and] rest.“
“Cycling a lot of times is helpful, [as well as] injection treatments such as cortisone, hyaluronic acid, and PRP [platelet-rich plasma therapy],” Soppe suggested.
Soppe himself said he still performs meniscectomies but only under very specific circumstances, namely when a patient’s meniscus tear is displaced, out of position, and therefore potentially causing other issues, and only when the above methods, including giving it time time, have failed to help.
He also suggested that for some, osteoarthritis may be sufficiently advanced that full knee replacement is a more sensible option than meniscectomy.
Previous meniscectomy surgery is a known risk factor for successful knee replacement surgery.
Arciero noted that there may still be a place for meniscus repair, saying: “In certain cases of acute, traumatic injury to the knee joint, there remains the necessity to perform appropriate surgery to repair the meniscus. However, in the majority of routine meniscus tears/pain, the evidence shows alternative treatments are more effective long-term.”
In the study, the investigators performed diagnostic arthroscopy for participants in the sham group, noted Soppe. That procedure typically involves injecting a saline solution into the knee, slightly inflating it to provide better visibility for the tiny cameras that are to be inserted into the joint.
“They flushed the knee with fluid, which we call lavage of the joint,” he pointed out. “To me, that is not sham surgery, [because] even though they’re not messing with the meniscus, they’re potentially removing these types of cell mediators, like cytokines, interleukens, TNF-alpha, that probably modulate the pain.”
“It’s not exactly sham surgery,” he said, raising the possibility that those participants might have received some unintended pain relief after all.
