In our to cut, or not to cut series, we try to answer the question of whether surgery is the best treatment for a particular condition. We are in the middle of ski season at the time of writing this, so this week on the “to cut, or not to cut” series, meniscus injuries are on the chopping block.
I have to say, the amount of articles and research about meniscus injuries is overwhelming, and for a while I felt like all I was learning was that I had more questions than when I started. But the conclusion that I have come to is this:
Almost all meniscus injuries should be managed with physical therapy first.
Obviously I am biased. I believe in what I do because it has worked for me and so many of my patients. But if you are a naturally skeptical person (like me) and don’t want to take my word for it, I’ve laid out some of the reasons why I’ve come to this conclusion.
Over 500,000 partial meniscectomies (partial meniscus removals) are performed each year in the United States. You would expect the research behind these surgeries to be incredibly supportive and clear cut right? Surprisingly, this is not the case. (1)
Meniscus tears are the quintessential "pathoanatomical treatment approach" injury, which focuses on restoration of normal anatomy as a treatment for pain and dysfunction. This model assumes that your pain is happening because of your “abnormal” anatomy. This treatment model, if used in isolation, can lead to unnecessary surgeries, confusion, and decreased participation in the activities of life that give us joy. However, when we use our knowledge of anatomy as a guideline to inform our treatment methods, then we can focus more energy on the big picture: function.
With that in mind, let’s use anatomy to develop some guidelines, and get an understanding of how the meniscus works.
Image: link
Each knee has two menisci, one medial (inside), and one lateral (outside), that are made up of fibrocartilage similar to that of a ligament. They create a stable footing for the thigh bone (femur) to sit on top of the shin bone (tibia).
Anatomically, the menisci provide stability to the knee. They help prevent the femur from shifting on the tibia by acting like chock blocks, similar to how airplane wheels are held in place.
Image (left): link
Image (right): link
Now that we know what it is, and what it does, how does the meniscus become injured? There are two primary types of meniscus injuries: acute tears and degenerative tears.
These injury types sort of explain themselves, but it’s important to understand that degenerative tears often take time to develop and can be difficult to directly link to the source of knee pain. For example, if you went from having no knee pain, to having significant pain in a matter of a few weeks without an acute injury, it’s hard to say that your pain is happening because of a degenerative meniscus tear that may have been there 3 months ago when you were feeling fine.
Acute meniscal tears often happen from a twisting, pivoting, hyperflexion, or medially directed force. Both acute and degenerative meniscus tears can result in catching and locking of the knee, swelling, stiffness, as well as pain near the joint line (see image below).
Image: link
So why would a health care practitioner recommend surgery? The primary theory for performing surgery on the meniscus is that without repairing the damaged structure, the knee would be less stable and less able to absorb shock, which would increase the risk of osteoarthritis in the long term. However, there is no significant evidence that a partial or full meniscectomy has any significant health benefit. In fact, it could even increase the risk of developing knee arthritis. (3) Additionally, there is evidence that physical therapy treatment is just as effective as a partial meniscectomy at a 2 year follow up, as seen below. (4)
So that’s it then right? Close the book, meniscus surgery is out.
…Not exactly
There seem to be less studies comparing meniscus repair and physical therapy treatment. Depending on the location and shape of a meniscus tear, it may respond well to a surgical repair. Based on my experience and some research regarding meniscal root tears, surgical treatment of these injuries may be more effective than physical therapy treatment alone, especially in younger patients with acute traumatic tears. (2)
A common trend in the literature is that there is often little difference in outcomes between those who have surgery vs. those who only do rehab, which means that there are plenty of people who get satisfactory results with surgical treatment. When it comes down to it, a person’s beliefs about their body and the benefits of surgery vs. rehab alone matter greatly in the decision making process.
So what is the answer to our main question…to cut? Or not to cut?
As with most things, it depends.
But I can confidently say that for most cases, physical therapy is a good first line treatment. A physical therapist can evaluate your knee, help you manage pain, swelling, range of motion, and can help you re-introduce exercise into your routine. If you aren't progressing well and surgery is the next step, we can recommend an orthopedist that we've had good experiences with. And if you do get surgery, you'd probably benefit from some help getting back to the activities you love.
Do you have knee pain that might be due to a meniscus tear?
Disclaimer: The information provided in this blog post is for general informational purposes only and is not intended as medical advice.
Sources:
Järvinen, T. L., & Guyatt, G. H. (2016). Arthroscopic surgery for knee pain. BMJ, i3934 (link)
Faucett SC, Geisler BP, Chahla J, Krych AJ, Kurzweil PR, Garner AM, Liu S, LaPrade RF, Pietzsch JB. Meniscus Root Repair vs Meniscectomy or Nonoperative Management to Prevent Knee Osteoarthritis After Medial Meniscus Root Tears: Clinical and Economic Effectiveness. Am J Sports Med. 2019 Mar;47(3):762-769. doi: 10.1177/0363546518755754. Epub 2018 Mar 8. PMID: 29517925. (link)
Sihvonen R, Paavola M, Malmivaara A for the FIDELITY (Finnish Degenerative Meniscus Lesion Study) Investigators, et alArthroscopic partial meniscectomy for a degenerative meniscus tear: a 5 year follow-up of the placebo-surgery controlled FIDELITY (Finnish Degenerative Meniscus Lesion Study) trialBritish Journal of Sports Medicine 2020;54:1332-1339. (link)
van der Graaff SJA, Eijgenraam SM, Meuffels DE, et alArthroscopic partial meniscectomy versus physical therapy for traumatic meniscal tears in a young study population: a randomised controlled trialBritish Journal of Sports Medicine 2022;56:870-876. (link)
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