Meniscal injuries

Meniscal injuries

Meniscal injuries are amongst the commonest problems seen by knee specialists at Schoen Clinic.

Whilst our knee specialists commonly treat professional sportsmen and women who have sustained meniscal cartilage injuries, the majority of our patients tear their cartilages undertaking relative routine day-to-day activities.

Meniscus: structure and function

Every knee has two meniscal cartilages within it, one on the inner (medial) aspect of the knee and the other on the outer (lateral) aspect. Both act, together with the cushioning cartilage covering the ends of the bones as shock absorbers within the knee, also helping to provide stability to the joint.

These two C-shaped wedges of cartilage are made of a particular type of tough cartilage tissue, possessing the unique ability to absorb and dissipate the forces of day-to-day impact not only on sporting activity but also with every step you take.

However, as the knee does not act as a simple hinge, but also has a small degree of rotation within it, these rotating forces can on occasions lead to a pinching of the cartilage– thus causing damage. If an excessive amount of force, either as a direct result of a single twist or an accumulation of forces during unaccustomed exercise occurs, then the threshold for this structure can be exceeded, leading to a tear. Once the tear reaches the surface of the meniscal cartilage, healing of this is unlikely to occur.

It is for this reason that many cartilage injuries are very slow to settle, with many never settling at all, thus requiring surgical intervention.

Diagnostics: we take a close look at your meniscus

The diagnosis of meniscal cartilage injury is made by a combination of a thorough consultation, where our experts at Schoen Clinic will listen to the history of the injury. A careful physical examination may reveal the following tell-tale signs of a meniscal tear, such as:

  • Fluid present in the knee, known as an “effusion”
  • Marked pain on direct compression of the meniscus along the joint line
  • Discomfort when squatting
  • Clicking within the knee

In addition, we may carry out imaging tests to create a comprehensive clinical picture. These can include x-ray examination to reveal the condition of your bones, and magnetic resonance imaging (MRI) for a detailed view of your soft tissues.

X-ray images to assess damage to your knee joint

X-rays can be useful in conjunction with MRI scans to assess concurrent bony pathology within the knee. X-rays reveal a clear picture of dense structures, like bone, which can assist in determining if there are any other potential causes for your pain like osteoarthritis, loose bodies or fractures.

Magnetic resonant imaging (MRI)

After an initial examination, your consultant may refer you for an MRI scan of your knee.

MRI scans produce high-resolution images of the soft tissues in and around the knee and are very useful to assess for cartilage tears. These scans have the advantage of not producing any harmful radiation. The high degree of definition within the MRI scan allows in-house radiologists to identify any tears within a meniscus with an extremely high level of accuracy (approx. 98%). By working exclusively with specialist radiologists with a clear interest in this area, this provides a very real diagnostic advantage for the surgical team as even subtle injuries will be detected.

It is, however, useful for consultants to have seen and assessed your knee prior to the MRI, as he or she will be able to tailor the scan request to assess the damaged part in question in more detail.

Meniscus tear symptoms

A significant twisting injury whilst playing sport (e.g. football or skiing) may well result in a meniscal tear, but equally even day-to-day actions such as getting up from sitting on the floor (e.g. in a yoga class) can produce exactly the same result, especially in the older age group e.g. in orthopaedic terms this refers to patients over 40. After this age, the cartilage has started to turn from a very resilient, tough rubbery construct, to a more brittle one that is not as elastic as it once was. It is for this reason that a simple twisting injury can cause a small split within the cartilage.

The meniscus has a very limited capacity to heal by itself because the vast majority of it does not have a blood supply. This means that symptoms from a torn cartilage will often persist long after one would expect other injuries to have healed. It is not unusual for the sharp pain of the injury to improve after several weeks, only for it to return each time sport is attempted.

Some classical symptoms for meniscal injury include some or all of the following:

  • Occasional sharp stabbing pain on either the inside or outside of the knee
  • Limitation in the range of motion, particularly deep bending
  • Pain on kneeling/squatting
  • Pain climbing stairs
  • Pain made worse by exercising
  • A catching/clicking sensation
  • A feeling of ‘giving way’/instability
  • Pain at the back of the knee - often due to a Baker’s cyst (due to excess fluid related to the meniscal tear)
  • Pain from a torn cartilage may vary between a sharp stabbing pain to a dull ache and it may be intermittent or continuous
  • Occasionally, there is no pain at all associated with these injuries but simply an inability to completely straighten the leg, i.e., locked knee. This is caused by the torn meniscus jamming

Causes: how meniscal injuries occur

Meniscal injuries can occur at any age although, contrary to popular opinion, most commonly they are found in the older age group. As we age the cartilage material itself becomes more brittle, thus the tendency for it to tear increases significantly.

In the younger population, normally only significant trauma during sporting activity causes tearing, whereas, in the 40+ age group, tearing can occur more easily as a result of an accumulation of stresses, either during a single exercise or over a period of time. Consequently, it is not necessarily a single traumatic event sporting that can cause a meniscal tear, but quite often even simple day-to-day activities such as an unusually long walk or prolonged/unaccustomed exercise.

It is also possible to simply tear the cartilage in a single abnormal movement, for example when getting up from a kneeling or cross-legged position on the ground.