What is a Meniscus?
A meniscus is an anatomical structure made of fibrocartilage (mix of fibrous and cartilaginous tissue, resulting in an overall structure owning both tough and elastic characteristics), located inside a joint cavity. In the human body you can find menisci in the wrist, part of the shoulder joint, the jaw, but their “most famous” location is in the knee (they are attached on the tibial plateau, in regards of the femur condyles). Their shape is usually called “half crescent” due to the image of a half moon it represents.
The role of a meniscus is to facilitate the articulation between the two bones composing a joint, enhancing what is called the “congruence” of a joint. This will act in favour of a better shock absorption by the joint and a reduction of the frictions created during any movement. A meniscal tear occurs when there is injury to the meniscus, this can be caused by lots of different factors which will be described below.
What are the common causes of a Meniscal Tear?
The most common cause of a meniscus tear in the younger population is often when playing sports. This injury usually happens following a mechanism of twisting and/or brutal rotation of the knee while in movement: a typical example of movement leading to such mechanism can be found in basketball where a player would brutally change direction with the body weight bearing predominantly on one leg more than the other one. In the case of a traumatic injury leading to a meniscal tear (for example when skiing), the meniscus isn’t always the only structure involved: the cruciate and collateral ligaments can also be affected, part of a complex injury called an “unhappy triad”. This injury occurs due to a lateral force applied on the knee with the foot fixed on the ground. The menisci can also degenerate with age, and the tear would in this case result from a minor injury.
What are the symptoms of a Meniscal Tear?
One of the main symptoms an individual usually immediately reports when experiencing a meniscal tear is hearing an audible “popping” sound at the time of the incident. Walking may not be altered immediately after the incident but may be more difficult, with stiffness in the knee associated with progressive pain over the days following the initial onset.
The tear will lead to an inflammatory reaction in the body causing a swelling and sensation of heat in the affected knee. The swelling may not be immediate at the time of the injury, but usually will develop in the first hours.
The pain described by the patient can usually be precisely located and described along the joint line of the knee, either on its medial or lateral aspect depending on the meniscus affected.
Because of the pain and the inability to have full mobility in the knee, the patient may describe a sensation of instability in the affected leg and feeling like the knee is “giving way” when in action. In the case of a tear with detachment of a part of the meniscus, any active bending or straightening of the knee will be reduced with a feeling of something “locking” inside the knee.
Do I need to go to the GP or visit my local hospital?
A visit to the GP or a physical therapy specialist (physiotherapist, osteopath) is recommended when the first symptoms suspecting a meniscal tear are felt. While an osteopath will test and conduct a meticulous physical examination to help determine if the suspicion of tear is founded or not, only the GP can refer the patient to a local hospital for further imaging that will give a clear medical diagnosis.
How is a Meniscal Tear diagnosed?
There are orthopaedic tests that can be used to assess a suspicion of meniscal tear. However a full clinical diagnosis can only be ascertained with the support of medical imaging.
In this case, the best way of obtaining a clear image of the knee health and diagnosing a potential injury affecting the meniscus is an MRI: this method of imaging gives access to every structure (hard and soft tissue) in your body.
As soon as the first symptoms appear, it is recommended to consult a physical specialist (physiotherapist or osteopath for example) or GP. This will help with rapidly determining the severity of the potential injury, as well as conducting a specific examination of the area. Although the therapist won’t be able to medically diagnose a meniscal tear or its severity, with the use of orthopaedics test an estimation can be made, before referring to get an imaging medical diagnosis. Two tests are used to assess the integrity of a patient’s knee: Apley’s and McMurray’s.
While Apley’s test is conducted with the patient lying on their tummy, with the affected knee bent at 90 degrees combined with an applied distraction and then compression of the knee coupled to rotations in both directions, McMurray’s is conducted with the patient lying on their back, the knee fully flexed progressively brought into a 90 degrees flexion associated with an internal or external rotation.
Apley’s test is determined positive if pain is present during the test, and McMurray’s if a “click” is felt associated with pain. Both these tests are described as having a poor methodology with a sensitivity and specificity reported at 60% and 70% respectively (Egedus et al., 2007).
What are the treatment options for a Meniscal Tear?
If the tear is large or the patient is young, dynamic, and in need to get back to a physical activity as soon as possible, professionally or recreationally, surgery may be recommended. The surgery can have two purposes: either repairing the damaged parts of the affected meniscus, or if that isn’t possible then removing torn parts completely, which will be done through a knee arthroscopy.This is a type of keyhole surgery. In the case of a damaged meniscus due to old age and/or wear and tear, a full knee replacement may be required.
A more conservative approach may be used in the first steps following the medical diagnosis. Firstly it is recommended to rest, avoid any activity stressing the affected knee, loading it, such as twisting or bending the knee. If the pain is too severe, the use of crutches to offload the joint and meniscus can be beneficial. Icing the knee can help reduce the swelling and pain level experienced by the patient: it is recommended to do it regularly every day, for periods of 15 minutes at a time, 3-4 times per day. Finally, the use of painkillers and anti-inflammatories can help manage the pain level as well as the inflammatory process occurring in the affected knee. It is always recommended to seek the advice of your GP before taking any new medications.
Whether the patient uses a conservative or surgical approach, physical therapy may be recommended to you by your consultant. Physical therapists such as Osteopaths and Physiotherapists will work with you to help strengthen and stabilise joints such as the ankle and knee which is key to the overall stability of the rest of the lower limb. The therapist may also work on releasing tensions created by the scar tissue, as well as minimising compensations developing in the associated peripheral joints and muscles.
How long does the recovery from a Meniscal Tear last?
The length of recovery will vary between a conservative non-surgical approach and a surgical repair. In the case of a rehab protocol using a non-surgical approach (recommended when the tear of the meniscus occurs in a middle-aged population caused by wear and tear), the recovery time is estimated from 6 to 8 weeks, assisted with the use of physical therapy to help in gaining increased knee strength as well as an overall lower limb stability.
In the case of a surgery repair protocol, the time estimated before walking without assistance is between 4 and 6 weeks, followed by an additional 2 to 5 months before being able to return to heavy loading of the knee or practicing sports.
Can a Meniscal Tear be prevented?
There are two main causes leading to a meniscal tear: a traumatic incident, combining awkward single leg weight bearing with torsion, or wear and tear usually occurring with age. In both these scenarii, such an injury can’t really be prevented. But similar to an ACL injury for example, you can help minimise the impact of the injury and have the best chances to reduce the recovery and rehab length by doing good stability work of the lower limb (ankle, knee, hip). This stability can be found thanks to the muscles tonicity, and with balance and coordination exercises.
What are the best exercises for Meniscal Tear rehabilitation*?
There are a various range of exercises recommended for the rehab of a meniscal tear. Below is a non-exhaustive list of some of the exercises that can be done at any stage of a conservative rehab, and after being given the green light by your doctor following knee surgery. These exercises are designed to strengthen the group of muscles attaching to the knee joint:
Wall sits isometrics. This exercise is basic but used for many knee injury rehab programs. Start by placing your whole back against the wall, with a mild flexion of both hips and knees, averaging 120 degrees. From this position, lift one leg up off the floor, so your bodyweight is only resting on one leg. Hold this position for 15 to 20 seconds depending on the difficulty of doing the exercise and/or your pain level. This exercise can be repeated 3 times for each leg.
Knee extension. You can do this exercise while seated and it shouldn’t take more than 5-10 mins to complete. Sit with both legs bent and feet flat on the ground. Flex the foot of the affected leg. Start by slowly straightening the leg until it is fully straight. Then in a controlled movement slowly bring your foot back to the starting position. This exercise can be repeated 10 times each side, for 2-3 sets.
Hamstrings curl. This exercise can be performed with and without the resistance of an elastic band. Lie on your stomach, with your legs fully extended flat on the floor. Bring your heel towards the buttocks, one foot at a time, while maintaining a flexion of your foot in order to only activate the hamstrings. Slowly bring your leg down to the floor in a controlled manner. This exercise can be repeated 10 times for each side, for 2-3 sets. You can add more loading into the hamstrings by attaching an elastic band to your ankle creating a traction effect in the opposite direction of the movement you are performing.
*It is recommended to get the OK from your GP, Osteopath or Physiotherapist before doing any of these exercises.
References
Hegedus, E.J., Cook, C., Hasselblad, V., Goode, A. and Mccrory, D.C., 2007. Physical examination tests for assessing a torn meniscus in the knee: a systematic review with meta-analysis. journal of orthopaedic & sports physical therapy, 37(9), pp.541-550.