Meniscus Injury

The knee is a hinge joint where your shin bone (tibia) meets your thigh bone (femur). The knee joints bend and straighten and withstand considerable levels of force during weight-bearing activities of daily living (walking, stair climbing and running).

The menisci are half-moon-shaped pads of cartilage that are positioned at the top of the tibia ⁽¹⁾ and in part they act as shock absorbers. The menisci also nourish the joint cartilage, lubricate the joint and provide stability to the knee. The medial meniscus is particularly important for knee joint stability. They are made of a particular type of cartilage that gives them a tough consistency that is resistant to stress and strain. In general, after adolescence, the menisci have a poor blood supply which means injuries can take longer to heal.

Acute meniscus injuries can occur following trauma, including sporting injuries ⁽³⁾. It has been proposed that specific subgroups of patients (younger patients with acute meniscus tears) benefit more from surgery than others but there is a lack of strong evidence to support this notion.

The most common cause of acute meniscus tears is through trauma, whereas degenerative tears should be considered a feature of knee osteoarthritis and the ageing process. Sporting injuries are the most common trauma associated with acute meniscal injuries. Twisting the knee whilst weight bearing causes an increase in sheer force on the meniscus which can result in a tear ⁽³⁾.

Prevalence in the general population is low at less than 0.05%, however that is increased in athletes with figures of 12% to 14% of all knee injuries in this group⁽⁹⁾. When another injury occurs such as those suffering anterior cruciate ligament (ACL) injury, this figure increases again ranging from 22% to 86% ^{(7, 9)}. Men are thought to be up to 4 times more likely to suffer a meniscus injury than women ⁽¹⁾. They are the most common knee injury for athletes as a result of trauma ^{(3, 4, 7)}.

Musculoskeletal physiotherapists and other appropriately qualified healthcare professionals can provide you with a diagnosis by obtaining a detailed history of your symptoms. A series of physical tests might be performed as part of your assessment to rule out other potentially involved structures and gain a greater understanding of your physical abilities to help facilitate an accurate working diagnosis. If the treating clinician suspects a large or more traumatic tear, they may refer you for magnetic resonance imaging (MRI) to evaluate the knee and aid in decision making.

Your treating clinician will want to know how your condition affects you day-to-day so that treatment can be tailored to your needs and personalised goals can be established. Intermittent reassessment will ascertain if you are making progress towards your goals and will allow appropriate adjustments to your treatment to be made. Imaging studies like MRIs or ultrasound scans are usually not required to achieve a working diagnosis, but in unusual presentations, they may be warranted.

As part of your treatment, your treating clinician will help you understand the condition and what needs to be implemented to effectively manage your meniscal tear. This will include activity modification strategies as well as other useful treatments aimed at reducing discomfort. Regular adherence to a condition-specific rehabilitation programme is important in the management of this condition. It should be noted that rehabilitation exercises are not always a quick fix but, if adhered to on a consistent basis (weeks to months), have been shown to yield positive outcomes.

Depending on symptoms, conservative self-management may be appropriate. Acute injury management such as ice, compression and elevation may help initially before a guided rehabilitation programme to improve the function of the knee.

In some instances, such as when there is significant locking or giving way, it may be more appropriate to refer for a surgical opinion. If the decision is made to undergo surgery, it is paramount that rehabilitation takes place before and after surgery in an attempt to regain the function of the knee and achieve your goals.

Return to sport is entirely possible after a meniscus injury regardless of if you have surgery or not. For patients wanting to achieve a high level of function or return to sport, we would encourage a consultation with a musculoskeletal physiotherapist as you will likely require further progression beyond the advanced rehabilitation stage. Before returning to sport, a rehabilitation programme should incorporate plyometric based exercises; this might include things like bounding, cutting, and sprinting exercises.

In younger patients with no osteoarthritis, the meniscus is important in protecting the joint and sometimes a surgical repair may be recommended. Repairing the meniscus has been shown to reduce the risk of early onset osteoarthritis when compared to removing the meniscus (meniscectomy) so is recommended as the surgical option of choice. However, studies in various countries have shown that meniscectomy is much more commonly used than surgical repair ⁽⁸⁾. Both surgeries are completed arthroscopically (keyhole surgery) and require a progressive rehabilitation after surgical intervention ^(7,8).

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