Knee injuries - meniscus

Health and Nutrition > Diseases > K Reviewed by Mr Dai Rees, consultant orthopaedic surgeon

What kinds of knee injury are there?

In the knee, there are several structures: the collateral ligaments, the cruciate ligaments , the articular (joint) cartilages and the menisci. If there is injury to the knee, it is possible that more than one of these structures may be injured at the same time.

What are the menisci?

In the knee joint there are two half-moon-shaped pieces of cartilage called menisci lying firmly on the shin bone.

The outer or external meniscus is called the lateral meniscus. The inner or internal meniscus is called the medial meniscus.

It is primarily the job of the menisci to function as load distributors when we walk or run. If the menisci were not there, the articular cartilage would be too heavily loaded and could be damaged.

The menisci also help to keep the knee stable.

How do meniscus injuries occur?

Meniscus injuries mostly occur when the knee is wrenched. In a weight-bearing twisting manoeuvre, the meniscus may be caught between the thigh bone and the shin bone and subsequently damaged.

This type of injury is common if someone is tackled during a football game.

What are the symptoms of a meniscus injury?

Shortly after the accident has happened, it is difficult to diagnose whether a meniscus injury has occurred unless the knee is locked. There can be a swelling, but not always. Even the most classical symptoms may fail to appear at first.

The classic symptom is a locked knee that cannot be straightened, eg if one has been sitting with bent knees. The knee can suddenly lock on twisting and then unlock with an audible click.

Another classic symptom is pain and swelling of the knee after it has been overloaded.

How does a doctor diagnose a meniscus injury?

First and foremost it is important to find out how the injury occurred and whether the knee was locked. The doctor will feel along the knee's joint-lines and examine whether there is soreness corresponding to a meniscus. On moving the knee a little, the meniscus-click might be felt or heard.

Finally, an arthroscopy of the knee can be carried out. This is usually done under general anaesthesia. A diagnosis can be made and the meniscus tear attended to.

How is a meniscus lesion treated?

There is no standard treatment of meniscus lesions. But as a rule of thumb, as much of the meniscus as possible will be saved.

If there is only a minor lesion in the free edge of the meniscus, it may be enough to smooth it out a little, or even to do nothing at all.

If there is a more major tear, the torn portion is usually removed arthroscopically.

If there is a long split in the meniscus, it is possible to stitch it. This is also performed arthroscopically.

As the blood supply to the meniscus is limited, not all large tears are amenable to repair. Attempted repair is often tried in young people.

If the meniscus has been repaired, weight-bearing is limited for three weeks. It will be six weeks before a full range of movement is achieved.

If a portion of meniscus has been removed (a procedure called partial menisectomy), the patient can walk again as normal.

.

The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care or attention by a qualified practitioner. The materials in this web site cannot and should not be used as a basis for diagnosis or choice of treatment. Conditions for use

© Copyright 1998 - 2009 NetDoctor.co.uk - All rights reserved