Our knees have both a lateral and a medial meniscus. It is a fibrocartilage layer that separates your femur (thigh) from your tibia (shin). They are pivotal to providing rotational stability to your knee and act as a shock absorber during motion, helping to disperse compressive forces throughout the knee.
Meniscus tears come in many variations, and can happen to both medial and lateral meniscus. Medial is more common, though lateral tend to be slower to settle. The majority of torn meniscus injuries improve with graded rest, expert physiotherapy and a planned return to sport or activity. Occasionally, surgical intervention is required, though this is far less common these days for degenerative tears.
How does it occur?
Meniscus injuries can be caused by many, and sometimes poorly understood, mechanisms. Typically, an acute, traumatic tear results from a twisting, cutting or fast change of direction motion. Degenerational tears can occur with simple turning, golf swings, getting out of the car, kneeling or deep squatting. These are motions people would have done millions of times, then suddenly experience pain. We simply don't have all the answers as to why these tears occur.
Signs and symptoms of a torn meniscus.
Pain along the inside or outside of the knee joint is common, plus or minus joint swelling. Usually, a history of twisting with a slightly flexed knee is noted. Occasionally people experience locking, collapsing or giving way sensations. You physiotherapist has multiple clinical tests to determine a meniscal tear, including Duck Walk, McMurrays, Effusion Sweep and Joint Line Palpation tests.
Do you need scans?
Generally, no, and if you do it may be after 6 weeks of conservative rehabilitation. For an acute traumatic injury, scans may be ordered at initial consultation. Xrays don't show meniscal tissue. MRI's do, though isn't first treatment option, as scan results don't necessarily correlate with pain or functional levels. You should never diagnose or plan your rehabilitation based just on an image. You need to factor in your functional status and rehabilitation goals at all times. A study by Zanetti et al (2003) showed that 36% of non-symptomatic knees had a tear on MRI (age 18-73), without any symptoms.
What should you do about it?
First step, rest from the aggravating activity and seek medical opinion. You local knee physiotherapist will be able to perform the above mentioned tests and give you a clear idea on recovery plan or whether surgery is required. Usually, a standard meniscal tear will take 6-8 weeks to settle with conservative management. This can vary quite widely.
Should you have surgery?
Generally not. Your knee physiotherapist will assist you in making this decision. Main consideration needs to be around whether your meniscal injury is degenerative or acute. A recent systematic review of the medial research literature by Kahn et al (2014) showed no evidence for surgical intervention in degenerative meniscal tears versus conservative rehabilitation management. For an acute meniscal tear, with an inability to extend or move the knee, surgery may be required and has a high success rate. Rarely, will you need to rush into making a decision.
To make a booking to see your local knee physiotherapist for treatment of your meniscal tear or strain, please call your local clinic or book online.
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 : Canadian Medical Association Journal, 186(14), 1057–1064. http://doi.org/10.1503/cmaj.140433
Patients with Suspected Meniscal Tears: Prevalence of Abnormalities Seen on MRI of 100 Symptomatic and 100 Contralateral Asymptomatic Knees. Marco Zanetti, Christian W. A. Pfirrmann, Marius R. Schmid, José Romero, Burkhardt Seifert, and Juerg Hodler. American Journal of Roentgenology 2003 181:3, 635-641