Synovitis of the knee

Synovitis is a condition of discomfort that leads to irritation and inflammation of a joint.

Each joint is surrounded by a capsule, the inner layer of which is called the synovial membrane, or synovialis for short.
This synovial membrane produces a fluid called synovial fluid. It is able to adapt to the different joint movements: it can expand and contract.
When the synovial fluid is irritated, more synovial fluid is produced, which leads to overheating, stiffness and swelling in and around the joint.

In 80% of cases, a slow-growing, benign synovial membrane tumor causes pain and swelling in the synovial of the knee. For other joints, such as hip, ankle or shoulder, this is less common.
Often synovitis is noted during arthroscopy of the temporomandibular joint, the movable connection between the lower jaw and the skull.


Who suffers from reactive synovitis?

Synovitis is found in both men and women, although rheumatoid arthritis (which involves inflammation of the synovialis) is three times as common in women. The systemic infection (septic arthritis) occurs mainly in an age under 15 years and over 55 years and mainly affects men (Marquez).

What are the causes of synovitis?

Reactive synovitis has many causes, including infections (e.g. septic arthritis, tuberculosis), direct violenceallergic reactionsgout, overloading of the joint, inflammatory, systemic, autoimmune diseases (e.g. rheumatoid arthritis). Synovitis can be limited to a single joint as an acute incident or occur as a symptom of a systemic, chronic disease involving multiple joints.

The overproduction and deposition of uric acid, as gout brings, increases the risk of reactive synovitis. Leukemia, lymphoma, psoriasis or chemotherapy treatments are among the risk factors for gout. Alcohol consumption, chronic kidney failure and high blood pressure can lead to reduced excretion of uric acid from the body, which in turn results in uric acid being deposited in the joints; in this case, the risk of gout and associated synovitis increases.

Risk factors: People who perform repetitive movements with their knees, hand, wrists, elbows, and shoulders, such as assembly line workers and throwing athletes, are at increased risk for synovitis. The inflammation can affect the joints of the lower extremities. Here, people who perform repetitive activities with hips, knees, feet and ankles are at risk, for example, who run, climb and jump a lot.

Symptoms of synovitis

Symptoms include:

In the case of synovitis, the symptoms can be alleviated by cold or heat treatment.

Diagnosis of synovitis

Medical history examination: the symptoms of synovitis are often linked to certain activities.
As a rule, the patient has performed repetitive movements or excessively stressed the joint over a long period of time. If symptoms are not associated with certain activities, infections, allergic reactions or inflammatory diseases may be considered.
This information indicates the concomitant diseases causing synovitis. One or more joints may be affected. Patients complain of joint pain, swelling, overheating and stiffness. The symptoms of synovitis could be relieved by cold therapy or heat therapy.

Physical examination: the joint should perform the maximum possible movement in order to assess pain, stiffness and possible joint noises (crepitus); tests must be carried out to check the muscular strength of the muscles acting on the joint; in this way, it can also be determined whether pain is caused by the strain.
The doctor must examine the joint play to assess the mobility and irritability of the joint. This movement is usually limited and painful. If synovitis is the result of trauma, there may be excessive joint play. The joint is swollenreddened and overheated.

Laboratory and imaging techniques

Upcoming laboratory tests include: complete blood count, urine analysis and erythrocyte sedimentation rate (ESR) to measure inflammation. At the doctor’s discretion, an analysis of rheumatoid factors and/or synovial fluid (after suction) with Gram staining can also be carried out. X-rays can be used to examine the condition of the articular surfaces. An MRI can provide valuable information, especially in the early stages of inflammation.

Treatment of synovitis

For synovitis, therapy includes taking anti-inflammatory drugs, cold and heat treatment, cortisone injections, and taking a break from symptom-enhancing activities. In addition, medicines for pain control and a bandage used day or night to immobilize and support the joint can be used. Once the symptoms have stabilized, movement exercises must be performed to improve the range of motion of the joint and restore the strength of the muscles acting at the joint.

In the case of destructive synovitis, which occurs in diseases such as rheumatoid arthritis, surgical removal of the synovial membrane may be necessary (synovectomy). Synovialis can also be destroyed by laser therapy or targeted injections of chemical substances (chemical ablation).

Rehabilitation for synovitis

Kinesio Taping for post-operative knee, knee swelling, bursitis and strain: Action: emptying. Form: Two stripe fan. Length: 25cm. Adopt the strips forming a double-fan-shaped cross-section that covers the entire knee, from top to bottom. Flex the knee as much as possible to enable them to stretch and apply without tension.

With synovitis, the goal of rehabilitation is to relieve inflammation and pain in the joint, as well as to regain normal range of motion and joint strength. In the initial phase of synovitis, the physiotherapist may advise elevating the joint to promote decongestion. The therapist will show the patient how to protect the joint to the point of swelling with the help of an elastic bandage, bandage or soft foam cushion without exposing pressure to the inflamed joint.

There are several treatment methods to control synovial inflammation. In the initial stages, as long as the joint is overheated, the physiotherapist may put ice packs on to relieve swelling and pain. Tecar therapy can be used to relax the muscles near the joints and to relieve discomfort and inflammation.

If pain and swelling subside, heat treatment is carried out to reduce the symptoms and increase blood flow in the synovialis and thus stimulate healing. Ultrasound is also used in physiotherapy. The high-frequency sound waves generate heat that penetrates deep into the synovial membrane and the affected joint.

If the pain and swelling have subsided significantly, stretching exercises and passive mobilization must be performed by the physiotherapist to regain normal range of motion. The exercise program is gradually increased and includes active exercises for stretching and muscle strengthening to return to full joint functionality without pain. The rehabilitation program can be changed depending on joint position, stage of inflammation (acute or chronic synovitis) and surgical indication. However, surgical intervention is rarely necessary.

Complications of synovitis

With chronic synovitis, the synovial membrane can watch up to the articular surface and destroy the cartilage.

Prognosis for synovitis

Acute and isolated cases of reactive synovitis usually respond well to conservative (non-surgical) treatment. If the affected joint is immobilized, overwork-related synovitis improves after just a few days, but it can take up to 8 weeks for it to heal completely (Ryan). With chronic synovitis, the development of the underlying disease is crucial to the result. Relapses are possible if the synovial grows back after surgical, chemical or laser removal and the underlying disease causes inflammation again.

Return to work

As long as the synovitis has not healed, the occupational load on the affected joint must be limited as much as possible; here the temporary transfer to another department could be useful. A temporary use of aids is also conceivable. Professional activities must be organised in such a way that there is time for physiotherapy.

Synovitis is found in both men and women, although rheumatoid arthritis (which involves inflammation of the synovialis) is three times as common in women. The systemic infection (septic arthritis) occurs mainly in an age under 15 years and over 55 years and mainly affects men (Marquez).

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