Meniscus rupture, or meniscus injury, accounts for about ¼ of all injuries occurring to the knee joint, which can affect either young, active individuals due to an injury during a sporting activity or older individuals due to degenerative disorders. But what are menisci and how can a meniscus injury be diagnosed? Is a physiotherapy treatment or an meniscus operation?

In this article, we will try to answer these questions, understand when to seek professional advice from a musculoskeletal specialist, and what to do to resolve this issue. In particular, we will look at the most common and effective exercises recommended during the rehabilitation phase after a meniscus tear.

Menisci: What are they?

Many people have surely heard, especially in the sports world, of someone who has 'ruptured their meniscus' without actually knowing what it is. What are menisci? The menisci are semilunar fibrocartilaginous structures (we can liken them to pads), triangular in cross-section, which are located in the lateral and medial aspect (innermost part) of the knee joint (between the femur and tibia). The vascularisation of the menisci is rather peculiar in that it tends to decrease with age Whereas in children, more than half of the meniscus is vascularised, in adults the vascularisation is 10%-30% and mainly concerns the outer part (called the vascular or red zone), where we also find free nerve endings and mechanoreceptors, which are completely absent in the inner part (called the non-vascular or white zone).

It is precisely because of this poor vascularisation at the level of the menisci, healing times after a meniscus injury depend on various factors that we will see below. The medial meniscus (or inner) has a "C" shape. The medial collateral ligament fits over it and together they stabilise the knee joint especially against valgus stress; it is less mobile and therefore more prone to injury. The lateral meniscus, on the other hand, is shaped like an 'O'. It has no contact with the Lateral Collateral Ligament and, being more mobile, is rarely subject to injury or rupture.

How do menisci move? During knee extension they move anteriorly, due to their joint morphology but also due to the pull of the quadriceps; while during knee flexion (i.e. when we bend the leg) they move posteriorly. Now that we understand what the menisci are, let's try to understand what they are used for. Among the main functions of the menisci are:

-Cushioning the load:  reduce friction forces on the joint 

-Load distribution: increasing the contact area between the femur and tibia so as to reduce joint stress and thus avoid early degenerative phenomena (such as arthrosis)

- Stabilising the joint: increasing the articular congruence between the bone surfaces

- Joint nourishment:  lubricating cartilage by bringing nourishment through synovial fluid

-Proprioceptive role : contribute to the proprioception of the knee due to the presence of mechanoreceptors and free endings

Meniscus rupture: causes

An injured meniscus can mainly affect young people,  especially when engaging in sports activities (with or without contact, such as football, rugby, basketball, skiing, tennis) that involve stopping, jumping and changes of direction, they are more likely to suffer a meniscus rupture, especially an injury to the medial meniscus, due to a traumatic event, while elderly individuals are more likely to suffer a meniscus rupture due to a traumatic event. a degenerative lesion, therefore meniscosis (especially those who perform activities that involve frequent squatting). Risk factors, i.e., factors predisposing to injury, include female sex, advanced age, high body mass index (BMI), low levels of physical activity, or delayed repair of the Anterior Cruciate Ligament (ACL).

One of the most common injury mechanisms is that affecting the "posterior horn of the medial meniscus". especially after the return in extension from maximum flexion (as when doing a deep squat), where precisely the medial meniscus gets caught at the level of the femoral condyle and can no longer slide forward, it is pinched in the posterior horn.

How can a meniscus injury be detected? The specialised physiotherapist is able to use tests, in particular the McMurray test, Apley's test, Thessaly test and Ege test, to test the meniscal integrity, and any positivity to these tests (which reproduce pain in the patient) could lead to a meniscal problem. Importantly, combining the results of the various tests remains the best way to increase the diagnostic accuracy of the physical examination to detect a meniscal injury.

Is it always necessary to have an MRI or X-ray? We know how, just like other types of conditions that can afflict the musculoskeletal system (e.g. the presence of a herniated disc in the case of lumbosciatica), 'pain' does not necessarily indicate 'rupture or lesion'; there are in fact subjects who, despite having a meniscal lesion visible on Magnetic Resonance Imaging (MRI), are completely asymptomatic, and subjects with significant symptoms at the knee, do not actually have any sign of injury visible on bioimaging. The clinical examination that attests to a mechanical block that restricts the entire movement and investigates the presence of instability is certainly one of the main reasons for an in-depth diagnostic examination through MRI or a possible surgical consultation. Knee arthroscopy is considered the gold standard for the diagnosis of meniscal injuries.

How can meniscus injuries be classified? Depending on location, we have lesions of the anterior horn, posterior horn or body. Based on shape, however, we distinguish:

• -Longitudinal injuries
• -Radial injuries
• -Horizontal injuries
• -Flap injuries
• -Beak injuries
• -Bucket-handle injury

Meniscus injury: symptoms

Symptoms of meniscus injury are common to other clinical conditions affecting the knee, as there are many structures in this joint that can suffer and thus be a source of pain (ligamentous lesions, tendinopathies, etc.), so a history by the specialised physiotherapist and a careful clinical examination are of fundamental importance. In fact, it is necessary to investigate the traumatic event and therefore any torsion injuries of the knee (in sportspeople, the triggering movement is generally a torsional movement with a flexed knee), the presence of delayed swelling with meniscus inflammation (after about 6-24 h after the injury) and any episodes of locking or collapse of the knee. Among the main symptoms of medial or lateral meniscus injury are :

• Pain during palpation at the level of the joint interline (medial or lateral)
• Pain and limitation of movement during maximum knee flexion or extension
• Swelling 
• Hematoma/spillage
• Episode of blockage or failure
• Presence of joint shocks
• Pain when administering meniscal tests (McMurray test and positive Thessaly test)
• Pain during major daily activities such as walking, climbing and descending stairs, kneeling or performing other activities under load

Meniscus rupture: physiotherapy treatment or surgery?

Meniscus injury can be cured through physiotherapy treatment or through surgical treatment. Which to choose? Certainly the type of treatment depends on many variables such as the characteristics of the subject and the type of lesion. As far as surgical treatment is concerned, there are different types of intervention that may involve a meniscectomy (i.e. total or partial removal of the meniscus, especially in individuals aged >45 years) or meniscus repair (especially in individuals aged <35 years); other types of surgery also involve prosthesis or transplantation.

You found out you had a ruptured meniscus and were told you had to have surgery? This is not always the case! In fact, some studies have questioned the role of surgery as a means of improving the symptoms reported by patients with a meniscus tear because, in general, no association has been found between structural pathology and self-reported results in pain or function during activities of daily living. We can say that surgical treatment should only be considered when there is a failure of conservative treatment or in those cases where there are persistent symptoms.

The approach of first choice must therefore be treatment based on rehabilitation aimed at symptom reduction, recovery of articularity and muscle strength, balance and proprioception, restoration of main functional activities in daily life, and recovery of sport-specific gestures. According to some studies in fact, physiotherapy is an effective treatment option for individuals with meniscus ruptures and, in the long term, provides better results than surgery in terms of recovering muscle strength and function. In a particularly acute phase, it may be useful to use anti-inflammatory drugs to reduce pain and swelling along with physiotherapy treatment.

Meniscus rupture: rehabilitation exercises

Are meniscus injury exercises effective enough to reduce pain? Which are the most important in the case of a meniscus rupture? To answer these questions, let's look at a 2017 study in which subjects aged between 18 and 40, with a meniscal lesion (visible on MRI) suitable for surgery, were followed for 12 weeks three times a week with a programme based on education and physiotherapy. The physiotherapy programme was based on exercises aimed at restoring mobility and strengthening the muscles by increasing, as the pain was reduced, the difficulty using weights, elastic bands, proprioceptive boards, etc.

Let us look at some of them:

-knee bends with heel resting on the couch

-lifting the extended leg

-isometric quadriceps strengthening exercises

-Ischiocrural strengthening exercises

-semisquats and lunges

This programme was considered feasible, relevant and effective by the patients, with important improvements in symptoms, functionality in activities of daily living, sports activities, and all subjects stated that they did not want to undergo knee surgery after finishing the physiotherapy programme.

Meniscus injuries: recovery times

As we mentioned earlier, the meniscus is poorly vascularised, recovery times for meniscus rupture depend on many factors such as the extent, location of the lesion, functional demand of the subject, etc.; generally 6 to 12 weeks are required.

Conclusions

Have you discovered you have a ruptured meniscus and are worried? Turn to an experienced physiotherapist, who will offer you rehabilitation treatment aimed at reducing pain, recovering movement and muscle strength, and enabling you to return to your sporting activity as soon as possible.

Source

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• Smith BE, Thacker D, Crewesmith A, Hall M. Special tests for assessing meniscal tears within the knee: a systematic review and meta-analysis. Evid Based Med. 2015 Jun;20(3):88-97. doi: 10.1136/ebmed-2014-110160. Epub 2015 Feb 27. PMID: 25724195.
• Tornbjerg SM, Nissen N, Englund M, Jørgensen U, Schjerning J, Lohmander LS, Thorlund JB. Structural pathology is not related to patient-reported pain and function in patients undergoing meniscal surgery. Br J Sports Med. 2017 Mar;51(6):525-530. doi: 10.1136/bjsports-2016-096456. Epub 2016 Sep 16. PMID: 27638845.
• Skou ST, Thorlund JB. A 12-week supervised exercise therapy programme for young adults with a meniscal tear: Programme development and feasibility study. J Bodyw Mov Ther. 2018 Jul;22(3):786-791. doi: 10.1016/j.jbmt.2017.07.010. Epub 2017 Jul 27. PMID: 30100313.