What is a Meniscus?
A meniscus is a crescent shaped disk that’s found in the knee. It functions as a shock absorber or cushion between the femur (thighbone) and the tibia (shinbone). It helps with knee stability, lubrication, proprioception, and congruity. Each knee has 2 menisci—one on the outer part (lateral) of the knee and one at the inner part (medial) of the knee. The lateral meniscus (outer) facilitates complex and combined movements at the knee such as sliding and rolling. The medial meniscus (inner) is less mobile than the lateral meniscus and is more prone to damage often from forceful twisting of the knee.
Causes of a meniscus tear...
The meniscus can be torn during activities causing direct contact/pressure from forceful twisting or rotation—often as a noncontact injury. Individuals who participate in sports related activities such as soccer, tennis, basketball, and football are at a higher risk for meniscus tears. Meniscus tears are not exclusive for athletes or individuals who participate in sports. As we age, the meniscus weakens and becomes brittle (degeneration that can lead to arthritis). Simple activities are associated with meniscus tears such as squatting, kneeling, or lunging.
Symptoms of a meniscus tear
- Pain: sharp, locking
- Loss of motion: inability to bend or straighten the knee
- May have clicking, locking, catching, or the knee “giving way”
- Popping sensation during the injury
- Knee joint effusion/swelling and tenderness in the knee joint
How is it diagnosed?
The diagnosis of a meniscus tear is through a combination of history, physical examination, and diagnostic tests. Your doctor will ask you to describe the symptoms, circumstances surrounding the injury and the mechanism of the injury. Other questions include location of the pain, sensation, previous injuries, self-treatments, and whether the patient is involved in leisure or competitive athletics as management decisions are dependent on these questions. Physical examination will be performed by your doctor which includes a thorough examination of the lower extremity such as comparing the uninjured to the injured side, observing for deformity, discoloration, swelling, abrasions, gait and stance—noting lower extremity alignment, fluid bulging in the knee, performing range of motion, and determining ligament stability. Diagnostic tests include performing a knee x-ray to rule out fractures and a magnetic resonance imaging (MRI) to take multiple pictures of the structure of the knee (cartilage, ligaments, meniscus).
What is the treatment for a meniscus tear?
Your age, activity level, type, size, and where the meniscus tear occurs play an important factor affecting the treatment management. The meniscus has limited blood supply and flows only to the outer edges of the meniscus. The outer one third of the meniscus is called the “red zone” due to the good blood supply while the inner two thirds— “red-white & white-white zone,” has limited blood supply. Outer tears tend to heal better due to the blood supply while inner meniscus tears tend to be more difficult.
So…Will I need surgery?
- Meniscus preservation is the overall goal, but like individuals, meniscus tears come in various shapes and sizes and each individual has various expectations and goals.
- So, do all meniscus tears require surgery? —no, meniscus surgery is not the only option. Various research studies have shown that arthroscopic surgery was not superior to exercise therapy. Meaning, non-surgical treatments were as effective as the surgical intervention.
- Does that mean non-surgical treatment is better? –no, each case is different and careful consideration with a shared-decision model approach and close communication should be taken by both the patient and their doctor.
- Some patients have benefitted from a nonsurgical approach only such as resting, ice, compression, elevation (RICE), non-steroidal anti-inflammatory medicines taken either by pills or cream, and physical therapy and exercise. Exercise has been shown to improve knee function, reduce joint pain, improve flexibility, and proprioception. Some studies have recommended to start patients with meniscus injury through the conservative approach and if it fails then surgery can be considered and carried out. On the other hand, others can and have benefitted from surgery especially if the injury is in the “red zone” such as in a meniscal repair. Partial meniscectomy can preserve some of the function of the meniscus and beneficial in the “white-white” zone.
Beaufils, P., Becker, R., Verdonk, R., Aagaard, H., & Karlsson, J. (2015). Focusing on results after meniscus surgery. Knee Surgery, Traumatology, Arthroscopy, 23(1), 3-7. DOI 10.1007/s00167-014-3471-x
Herrlin, S. V., Wange, P. O., Lapidus, G., Hallander, M., Werner, S., & Weidenhielm. (2013). Is arthrospic surgery beneficial in treating non-traumatic, degenerative medial meniscal tears? A five year follow-up. Knee Surgery, Sports Traumatology, Arthroscopy, 21(2), 358-364. doi: 10.1007/s00167-012-1960-3
Katz, J. N., Brophy, R. H., Chaisson, C.E., de Chavez, I., Cole, B. J., Dahm, D. L., … Losina, E. (2013). Arthroscopic partial meniscectomy was not more effective than physical therapy for meniscal tear and knee osteoarthritis. Journal of Bone & Joint Surgery, 95(22), 2058. doi: doi: 10.2106/JBJS.9522.ebo745
Katz, J. N., Brophy, R. H., Chaisson, C.E., de Chavez, I., Cole, B. J., Dahm, D. L., … Losina, E. (2013). Surgery vs physical therapy for a meniscal tear and osteoarthritis. The New England Journal of Medicine, 368(18), 1675-1684. doi: 10.1056/NEJMoa1301408
Kise, N. J. Risberg, M. A., Stensrud, S., Ranstam., J., Engebretsen, L., & Roos, E. M. (2016). Exercise therapy for degenerative meniscal tear in middle aged patients: Randomised controlled trial with two year follow-up. BMJ, 354(i3740), 1-9, doi: 10.1136/bmj.i3740
Khan, M., Evaniew, N., Bedi, A., Ayeni, O. R., & Bhandari, M. (2014). Arthroscopic surgery for degenerative tears of the meniscus: A systematic review and meta-analysis. CMAJ, 186(14), 1057-1064. doi: 10.1503/cmaj.140433
Monk, P., Roberts, P. G., Palmer, A. J. R., Bayliss, L., Mafi, R., Beard, D., … Price, A. (2017). The urgent need for evidence in arthroscopic meniscal surgery: A systematic review of the evidence for operative management of meniscal tears. The American Journal of Sports Medicine, 45(4), 965-973. doi: https:// doi-org.ezproxy3.library.arizona.edu/10.1177/0363546516650180
Mordecai, S. C., Al-Hadithy, N., Ware, H. E., & Gupte, C. M. (2014). Treatment of meniscal tears: An evidence based approach. World Journal of Orthopedics, 5(3), 233-241. doi: 10.5312/wjo.v5.i3.233
Roberts, A. (2016). The complete human body: The visual guide to the human anatomy. New York, NY: Dorling Kindersley Limited.
Sihvonen, R., Paavola, M., Malmivaara, A., Itala, A., Joukainen, A., Nurmi, H., … Jarvinen, L. N. (2013). Arthroscopic partial meniscectomy versus sham surgery for a degenerative meniscal tear. The New England Journal of Medicine, 369(26), 2515-2524. doi: 10.1056/NEJMoa1305189
Uphold, C. R., & Graham, M. V. (2013). Clinical Guidelines in Family Practice. Gainesville, FL: Barmarrae Books, Inc.