Menisci are crescent shaped fibro-cartilage structures that act to absorb shock, redistribute load, lubricate and provide stability to the knee. We have two menisci in each knee: one on the inside and another on the outside. These are referred to as the medial and lateral meniscus respectively.
Meniscus tears are often described as a single entity. However, individuals may present completely differently, including their reported onset of symptoms, clinical presentation and imaging findings.
An injury to the meniscus may be sudden and traumatic in nature, often the result of a twisting mechanism of injury. In contrast, some occur after seemingly little force or with no reportable moment of injury, usually in the context of a middle age to older individual with degenerative changes within their knee. It is important to be aware that a large proportion of the general population over the age of 40 will have a meniscus tear on MRI without the presence of symptoms (Lee, 2018). Research indicates that the presence of meniscus lesions in this population is a sign of osteoarthritis rather than a distinct clinical entity.
Management will vary significantly given the breadth of presentations and types of meniscus injuries. It is also important to correlate an examination with imaging findings to determine whether a meniscus tear is a likely source of a patient’s knee symptoms.
Historically, partial meniscectomy (i.e. partial removal of the meniscus) via arthroscopy was a popular orthopaedic procedure completed on many different types of meniscus lesions. However, recent studies have demonstrated the importance of preserving the meniscus, favoring meniscus repair or non-removal in traumatic tears and non-operative management in degenerative meniscus tears where possible (Chirichella, 2019). Of course, there are cases where meniscectomy is indicated and consultation with an orthopaedic surgeon should be sought to discuss your options.
There is robust evidence suggesting arthroscopy does not provide superior long term outcomes to conservative management for degenerative meniscus injuries (Brignardello-Petersen, 2017). As such, first line management should remain as conservative management, including weight loss, exercise and medical management.
The take home message here is: just because you have a torn meniscus, don’t automatically assume that it needs to be removed. Your orthopaedic surgeon and physiotherapist may recommend a period of conservative management first!
Brignardello-Petersen, Guyatt, G. H., Buchbinder, R., Poolman, R. W., Schandelmaier, S., Chang, Y., Sadeghirad, B., Evaniew, N., & Vandvik, P. O. (2017). Knee arthroscopy versus conservative management in patients with degenerative knee disease: A systematic review. BMJ Open, 7(5), e016114–e016114. https://doi.org/10.1136/bmjopen-2017-016114
Chirichella, Jow, S., Iacono, S., Wey, H. E., & Malanga, G. A. (2019). Treatment of Knee Meniscus Pathology: Rehabilitation, Surgery, and Orthobiologics. PM & R, 11(3), 292–308. https://doi.org/10.1016/j.pmrj.2018.08.384
Lee, Park, Y. J., Kim, H. J., Nam, D. C., Park, J.-S., Song, S. Y., & Kang, D. G. (2018). Arthroscopic meniscal surgery versus conservative management in patients aged 40 years and older: a meta-analysis. Archives of Orthopaedic and Trauma Surgery, 138(12), 1731–1739. https://doi.org/10.1007/s00402-018-2991-0