How dangerous is a knee joint effusion? | Knee joint effusion – How dangerous is it?

How dangerous is a knee joint effusion?

In most cases, a knee joint effusion can be treated conservatively and should be reduced by cooling, immobilization and anti-inflammatory ointments. If the effusion does not go back despite this treatment, a doctor should be consulted to decide on further treatment.

Symptoms

Articular effusion is manifested by a swelling of the knee, which also severely restricts mobility in the knee joint. The pressure built up by the fluid in the joint also causes pain, which is usually described as dull and indicated behind the kneecap. If the knee joint is not only swollen but also overheated and reddened, this is a sign of inflammation.

This can be a sign of an infection of the joint, especially after surgery, but without surgery it can be an indication of a disease from the rheumatological circle or a metabolic disease (such as gout or pseudo-gout). The most common cause, especially in older people, is an activated arthrosis (arthrosis relapse). Depending on the underlying cause, other symptoms may also be present.

You can find more information about this on our corresponding pages:

  • Acute knee pain – This may be behind it
  • Pain behind the kneecap
  • Inflammation in the knee
  • Torn meniscus
  • Symptoms of cruciate ligament rupture
  • Arthrosis thrust
  • Gout

The diagnosis of a knee joint effusion is generally based on a physical examination. A particularly important sign here is the so-called “dancing patella (kneecap)”. Since the effusion fluid is located directly underneath the kneecap, the examiner can perceive a rebound when the kneecap is pressed down vertically.

This practically ensures the joint effusion, although it should be noted that the sign only becomes positive when the fluid has already reached a quantity of at least 10ml. Of course, there are other ways to detect knee joint effusion. These include above all the classic imaging procedures such as: If an infection is suspected to be the reason for the knee joint effusion, a microbiological examination of the fluid from a puncture can also be carried out and thus provide an indication of the exact cause.

  • Ultrasound
  • X-ray,
  • Computer tomography (CT of the knee) or
  • The magnetic resonance therapy (MRI of the knee).

The knee joint effusion cannot be shown as well or as clearly in an X-ray image as in an MRT image. Nevertheless, the accumulation of fluid in the X-ray can be recognized as an opacity in the soft tissue around the bone. In principle, however, if there is a suspected knee joint effusion, an ultrasound examination is more appropriate, as this can confirm or rule out the suspicion quickly and without radiation.

Since X-rays are more suitable for imaging bony structures, it is possible to use X-rays to assess bony injuries as the cause of a knee joint effusion. MRI, on the other hand, allows better assessment of soft tissue such as muscles and ligaments, and fluid accumulations. In addition to ultrasound, MRI (magnetic resonance imaging) is a very suitable imaging technique for diagnosing knee joint effusion.

The knee joint effusion can be clearly identified as a fluid accumulation.It is located either behind the kneecap (patella), in the joint space or in the back of the hollow of the knee. If the volume of the knee joint effusion expands too much, the joint capsule in the area of the popliteal fossa may expand, which is then called a Baker’s cyst. With the MRI, it is usually possible to determine whether it is due to increased synovial fluid or serious accumulation of blood or pus in the knee joint.

However, the MRI not only allows the effusion itself to be determined, but also to search for the cause. For example, capsule tears, meniscus and cruciate ligament injuries or other injuries to the tissue around the knee joint can be seen. You can find more information on this topic here: MRI of the kneeThe therapy of a knee joint effusion is primarily causal, which means that the underlying disease is treated so that the effusion disappears in the long term.

Since the knee joint effusion is usually accompanied by pain due to swelling, the generally applicable PECH rule: rest, ice, compression, elevation. Frequently, overloading or traumatic injury to the surrounding knee structures is the trigger for the effusion, so immobilization and rest in the form of a break from sports activity is a good treatment approach. Compression bandages in combination with cooling and pain-relieving ointments can also be used to combat swelling.

The purpose of elevation is to allow the fluid to escape from the joint under the force of gravity. The knee joint effusion can be treated with anti-inflammatory ointments, which should be applied to the swelling. A Voltaren® ointment containing the anti-inflammatory and pain-relieving active ingredient diclofenac is particularly suitable for this purpose.

If the effusion does not subside within a few days as a result of these measures, a doctor should be consulted. If the knee joint effusion is due to a bacterial infection, antibiotic therapy must be carried out as soon as possible, otherwise the knee joint may be permanently damaged. If these conservative approaches to the treatment of a knee joint effusion do not work, the accumulated fluid in the knee joint can be drained during a joint puncture to relieve the symptoms.

It is important to work in a sterile environment, as a needle is inserted directly into the joint and, if the work is not sterile, germs can be carried into the joint. This would be a fatal complication of the otherwise simple and safe procedure. Before the effusion is punctured, the exact extent of the fluid accumulation can be estimated with an ultrasound.

Joint puncture ultimately offers 2 therapeutic approaches: A surgical intervention is generally not necessary and is only necessary in rare, complicated cases to drain the effusion and to repair possible damage after bacterial infestation. Physiotherapeutic follow-up treatment is recommended for aftercare. For smaller injuries, a knee bandage may also be useful to stabilize the joint after healing.

Depending on the severity of the cause of the knee joint effusion, healing after injuries, for example after a torn cruciate ligament, can take between 6-12 weeks. During this time, the knee should be protected and not subjected to extreme stress. You can read more information about this here: Knee school exercises

  • On the one hand, the effusion can flow off through the inserted needle
  • On the other hand, the puncture needle can also be used to inject drugs such as the anti-inflammatory cortisone.

    You can read more information about this here: Cortisone therapy for joint diseases

In addition to the typical treatment approaches, experience has shown that many a home remedy has also proven its worth. Since knee joint effusion is often of inflammatory origin and accompanied by swelling or redness, curd cheese or clay wraps help to relieve inflammation in the knee joint. To reduce overheating, a common symptom of knee joint effusion, a local cold application with ice packs can also be used.

Schüssler® salts and, as a homeopathic remedy, globules (e.g. Byronia alba, Rhus toxicodendron, Apis mellifica) are increasingly considered the home remedies of choice for the treatment of knee joint effusion. It is also helpful to reduce possible overweight, as this considerably reduces the stress on the knee joint.