What Is Joint Effusion? Is It The Excess Fluid Around The Knee

Jоіnt Effusion

A joint effusion is the presence of increased intra-articular fluid. It may affect any joint. Commonly it involves the knee.

Knee pain can be quite debilitating, as it is one of the most used and complex joints of the human body. The stability of the knee is due to four ligaments[1], muscles, and the actual joint structure. During the course of a normal day, the knee goes through a whole range of motions, from sitting, walking, twisting etc.

The term “water on the knee” is a generic term that describes the accumulation of excess fluid (edema) in or around the knee joint. As a result of a trauma, overuse, or other underlying conditions or disease, water on the knee may exist.

Often times, when a person has water on the knee, the underlying condition is arthritis. The term arthritis means “joint inflammation”. People also refer to arthritis as being “joint pain” as well.

The two most common types of arthritis are osteoarthritis (OA) which affects over 27 million people a year (mostly women), while rheumatoid arthritis (RA) affects over two million adults. Most of them being women over the age of 45.

Although these two types of arthritis affect millions of people and are the two most common types of arthritis, there are over 100 different types of arthritis.

When an individual has water on the knee, pain relief can occur when the fluid is removed from the joint. Pain relief can be subsided when this fluid returns.

You also may have “water on the knee” due to a traumatic injury. Fluid or blood can accumulate in the knee joint as a result of a meniscus tear or ligament injury.

Moreover, when an individual suffers an ACL tear, they may have also torn small blood vessels which can cause fluid to accumulate in and around their knee. Prepatellar bursitis can also cause water on the knee.

Our joints are extremely important for our functional activities, from the temporomandibular joint for eating and talking to the major weight-bearing joints such as the hips and knees. Our joints are designed to allow us to move about, to accomplish tasks and to bear weight, a job they do superbly well.

However, with injury, illness or disease our joints can be affected in various ways, limiting our abilities and causing stiffness and pain. Physiotherapists are trained to examine joints logically, determine the limiting factors and construct a treatment plan accordingly, with many techniques at their disposal.

In the human body, the junction between two bones is called a joint and they can function as a movement, weight bearing or force transmission joints according to their structure. The shoulder is a movement joint, the symphysis pubis a force transmission joint and the hip a weight bearing and movement joint.

Synovial joints are the most common type, making up all of our major obviously useful joints. Articular cartilage lines the bone ends to reduce friction and allow effortless movement, the synovial membrane lining the joint secretes synovial fluid and the joint capsule, a ligamentous bag, supports the joint against stresses.

Observing the patient as they walk into the examination room and sit down can give the physiotherapist valuable information about the state of their joint.

Slow and guarded movement is common, along with splinting of the joint and carrying it in a close and protected position to minimise joint stresses.

Once the physio has taken a history they will check out the joint visually, looking for swelling, effusion, warmth or a joint deformity.

If there is no obvious problem in a cool, settled joint the physiotherapist will need to stress the joint more thoroughly to find the restriction. However, a swollen, inflamed joint should be treated acutely as soon as possible.

Moving on from the relatively quick visual joint assessment the physiotherapist will start to palpate around the joint structures. This systematic manual examination allows the physiotherapist to clarify which parts of the anatomy are involved in the problem.

The typical areas tested will be the ligaments, the areas where the tendons and ligaments insert to the bone, the joint line itself and around the margins of the joint.

Any fluid in the knee, called an effusion, can be identified as it moves about if it is thin, it is very firm if the swelling is tight and it is thick and deformable if the swelling is older and stickier.

The active joint range of motion is then assessed and this is the joint movement the patient can do for themselves. Depending on the joint, this is expressed in degrees or as a proportion of the tested normal range on the other side, with the limitation of range noted and the reason.

The passive range is then tested and the physiotherapist moves the joint for the patient to see if any more movement is possible within the limits of discomfort.

If the active range is poor and the passive range full, i.e. the joint can move where it should, then weakness or pain may be the limiting factors. If the passive and active ranges are both restricted then joint stiffness may be the problem.

degenerative joint disease

Osteoarthritis, or degenerative joint disease, affects the elderly in parts of the body where it hurts the most.

A person suffering from knee osteoarthritis will most likely equate it with cardiovascular disease because the breakdown of articular cartilage of knee joints restricts movement and the patient has to follow a set regimen affecting his lifestyle.

Knee Osteoarthritis is due to injury, congenital disorder, or obesity. The deterioration[2] of articular cartilage, a smooth and fibrous connective tissue that acts as a protective cushion, narrows the joint space between bones. In time, the cartilage becomes grooved and fragmented and surrounding bones thicken or sprout into spurs.

Sometimes, there is additional swelling in the knees caused when synovium, a membrane producing a thick fluid to nourish the cartilage, becomes inflamed and produces an additional fluid known as ‘water on the knee’.

Water on the Knee

Changes occur due to constant rubbing of joint bones leading to deformity of joints that is equally painful.

Knee osteoarthritis is diagnosed through physical and pathological examinations of joints on either side of the knee including hip joints, checking on posture, and gait.

Once knee Osteoarthritis is confirmed, a treatment is suggested depending on nature and extent of damage and on the personal physical history of the patient.

Women over 60 years of age are high-risk factors for knee osteoarthritis as they spend a major portion of their lives doing physically demanding work that has a direct relationship with Knee Osteoarthritis.

Wearing high-heeled shoes also aggravates the pain. In youngsters, knee osteoarthritis is hereditary or due to some injury.

The knee also supports out weight in conjunction to the feet. Because of the abuse, we put our knees through there can be damage to the muscle, cartilage or the joint itself.

Some of the pain can be alleviated with the use of anti-inflammatory ointments or tablets, more severe cases need medical attention for a more effective treatment while some patients have even had their knee or knees replaced.

Knee Replaced


These can vary from person to person and can range from nagging to acute pain.

  • Discomfort while doing normal daily chores
  • Inflammation of the joint
  • Tenderness around the area
  • Instability [knee gives way for no reason]
  • Locking
  • A feeling of grinding
  • Popping
  • Stiffness
  • Injury to the knee
  • Can manifest itself with body aches and back pain


Traditionally caused by old age or injury, in this day and age there are more modern causes to this problem:

  • Septic arthritis
  • Osteoarthritis
  • Arthritis
  • Gout
  • Rheumatoid arthritis
  • Bursitis
  • Tendonitis

Moreover, of course, are all the injuries we can sustain due to sport e.g. dislocation, torn ligaments, cartilage injury etc. Painful knee injuries or conditions can interfere with a person’s way of life; some may require surgery while others need extensive rehabilitation therapy.

Best Water Exercises For Arthritis in The Knees, Hips, and Joints

If you have arthritis, either osteoarthritis or rheumatoid arthritis, you may have been thinking about doing some water exercises for your knees, hips or other arthritic joints. Water exercises, meaning either those used in aqua aerobics or resistance exercises, have been used for years by arthritis sufferers to find pain relief.

Over the years water exercises for arthritis have been fine-tuned so right now the best exercises have been developed by many experts in the field.

Exercise physiologists and doctors who specialize in sports medicine, rheumatologists, physical therapists and other health professionals[3] have come up with the best arthritis exercises for use in the water.

Water exercises work very well for people who have arthritis in their knees and hips. People without arthritis greatly benefit too. The floating feeling or buoyancy of the water takes the stress off knees and hips.

If you’re doing water exercises on your own it’s best does the exercises with the water at chest-height. If you’re going to take aqua exercise classes, the instructors may make aerobics a part of your exercise period.

Of course, aerobic exercise will greatly benefit your heart and may even lower your blood pressure.

Aеrоbіс Exеrсіѕе

Aerobic exercise in the water may consist of exercise that moves the large muscles such as those in your legs. You’ll be kept constantly moving to get the heart rate up and sustained for at least 20 minutes or so.

Resistance exercise in the water contributes to building your muscles and strengthens them. Noodles (which are flotation devices) are used to exercise the arms and shoulders.

The noodle is held at about the level of the waist while you are underwater then you lift it over your head. You will feel resistance. Make sure to start the lift under the water.

You can do these exercises on your own in a public pool, private pool, Jacuzzi or wherever you have access to water. You may want to check with your doctor before starting any new water exercise routine or before you sign up for any water exercise or aqua aerobics classes.
If you’re using public pools, try to find pools that use salt water rather than chlorine. Chlorine is very hard on the body and skin. Much is absorbed and the long-term effects are not known.

Precautions such as weight reduction, changing work routine, postures, diet, avoiding injuries, participating in physiotherapy, and exercise are advised.

Other methods of relief such as acupuncture, ointments, prescription drugs, magnetic pulse therapy, vitamin regimes, and topical pain relievers are temporary.

Read More: Arthritis Pain – Simplest Ways To Deal With Arthritis Pain

To avoid having water on the knees, individuals should consider seeing their physician on a regular basis, and avoid activities that result in physical contact with their knees.

Pain medications, such as Acetaminophen, can help to reduce swelling (see your physician before taking medications).

Weight management can also take the stress off of your joints, which could result in water on the knees. Ice and elevation of your legs can also help to reduce the fluid build up.

Water on the knee is not cured by a knee brace, but the underlying conditions can be supported by a knee support, proving to be a useful adjunct in your care.

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