Hip synovitis

Definition

Synovitis of the hip joint is an inflammation of the synovial membrane, accompanied by an accumulation of fluid in the joint cavity. The cause of development is usually an infection or traumatic lesion. In children, synovitis may be observed, provoked by viral diseases (for example, influenza) or prolonged walking. Pathology is manifested by pain, swelling, difficulty in support, and restricted movement. With infectious synovitis, there is an increase in temperature and symptoms of general intoxication. Radiography, ultrasound, and joint puncture are used to clarify the diagnosis. Treatment is usually conservative.

General information

Synovitis of the hip joint is an infectious or aseptic process in the synovial membrane of the joint accompanied by fluid accumulation in the joint cavity. It is a polyetiological disease (can occur for various reasons), more often detected in children and adolescents. The prognosis is favorable; in the vast majority of cases, it ends with full recovery. It rarely turns into a chronic form.

Anatomy and causes of the disease

The synovial membrane sits around joints and ligaments to protect them. It produces a small amount of fluid (lubricating secretion) that reduces friction and provides cushioning.

The exact cause of hip synovitis is unknown, but some theories cite a history of hip bone trauma or recent viral illnesses such as upper respiratory tract infection, bronchitis, or middle ear inflammation.

One reason for the development of inflammation of the hip joint is the entry of infection into the synovial fluid. This occurs against the background of any other infectious disease. In this case, fever, a significant increase in body temperature, and general ill health are added to the classic symptoms. First, it is necessary to fight the source of infection.

The main causes:

• sports injury;
• stretching;
• blood disorders;
• metabolic problems;
• endocrine pathologies;
• dystrophic pathology of the joint;
• overweight;
• allergies;
• bruises.

Infectious pathogens that most commonly cause synovitis include pneumococci, streptococci, staphylococci, Koch’s bacillus (tuberculosis), and STIs (sexually transmitted infections).

The cause of development is usually trauma to the joint (including sports injuries). Other causes include allergic reactions, endocrine pathology, neurological disorders, arthritis, hemophilia, and degenerative-dystrophic lesions (hip jointarthrosis). Sometimes, synovitis is observed in sciatica (inflammation of the sciatic nerve). The causative agents of infectious synovitis are usually pneumococci, staphylococci, or streptococci; less often, the inflammatory process develops against the background of a specific infection (syphilis or tuberculosis).

Classification

Taking into account the etiology in orthopedics and traumatology, the following types of synovitis are distinguished:

• Traumatic – the most common, occurs due to mechanical injuries (bruises, sprains).
• Infectious – develops when pathogenic microorganisms penetrate the synovial membrane. Contact, lymphogenic, or hematogenous spread of infection is possible.
• Reactive – is the body’s response to any pathological process (intoxication, somatic disease). It is considered as a type of allergic reaction.
• Transitory arthritis usually occurs in children and adolescents under 15 years of age; boys are more commonly affected. The cause is suspected to be viral infections (e.g., flu) or overloading the joint with prolonged walking.

In the absence of treatment or inadequate treatment, acute synovitis can turn into a chronic form, but this does not happen very often. By the nature of the effusion, acute aseptic (non-infectious) synovitis is usually serous, while acute infectious synovitis is purulent. Mixed exudate forms predominate in chronic synovitis: serous-hemorrhagic, serous-fibrinous, etc. The most unfavorable are fibrinous, accompanied by gradual sclerosis of the synovial membrane.

Symptoms of synovitis

The patient is bothered by pain in the hip joint. In aseptic synovitis, the pain syndrome is mild to moderate. The affected area is edematous, and changes in the shape of the joint can be detected (more noticeable when comparing both joints). There may be some limitations of support; when walking, the patient tries to spare the affected limb, and sometimes there is lameness. Movement is moderately or slightly limited. On palpation of the joint, pain increases. The “frog test” (attempting to spread the bent legs apart while lying on the back) reveals a limitation of extension.

In infectious synovitis, all symptoms are more pronounced. Pain is intense, swelling of the joint is clearly visible, and local hyperemia and hyperthermia are detected. There is a pronounced restriction of movements; the patient spares the leg, and walking is difficult. Symptoms of general intoxication supplement local signs of synovitis: a rise in temperature to 38-38.5 degrees Celsius, general weakness, lethargy, brokenness, chills, loss of appetite, headache, nausea, or vomiting.

Diagnosis

Diagnosis is made based on the examination results and the data of additional tests. Radiography of the hip joint is prescribed to exclude skeletal pathology and identify the possible cause of synovitis. Ultrasound of the joint is used for a detailed study of intra-articular structures. The most informative study to determine the nature and, in some cases, the cause of synovitis is the puncture of the hip joint with subsequent examination of synovial fluid.

In some cases, synovitis has to be differentiated with abdominal lesions, pathologic manifestations of the genital organs, and diseases of the lower spine. Usually, a thorough examination by a traumatologist is enough to rule out extra-articular pathology. In complicated cases, consultations with other specialists are appointed: neurologist, therapist, gastroenterologist, surgeon, urologist, etc. Sometimes, radiography of the spine in the lower sections is performed.

Treatment of hip synovitis

Treatment is complex, when drawing up a therapy plan, an individual approach is used, taking into account the form and stage of the disease, as well as the severity of clinical symptoms. Patients are recommended rest, analgesics, vitamin complexes, immunostimulants, and physiotherapeutic procedures. With infectious synovitis, antipyretics are used. In acute aseptic synovitis, non-steroidal anti-inflammatory drugs are used: diclofenac, ibuprofen, meloxicam, indomethacin, etc.

In recurrent synovitis, glucocorticoid blockades are performed. Chronic synovitis is treated with medications that regulate synovial fluid production and cell membrane stabilizers (aprotinin). Patients are referred to phonophoresis, electrophoresis, shockwave therapy, massage, and physical therapy. The indication for surgical treatment is irreversible changes in the inner shell of the joint (sclerotic degeneration, formation of hypertrophic villi and petrificates). Depending on the prevalence of pathological changes, partial synovectomy is performed, removing only the affected areas, or the synovial membrane is completely excised.

All these treatment options are available in more than 600 hospitals worldwide (https://doctor.global/results/diseases/hip-synovitis). For example, Hip arthroscopy can be done in these countries for following approximate prices:

Turkey $4.1 K – in 14 clinics

United States $12.6 K in 15 clinics

Germany $12.9 K K in 35 clinics

China $16.5 K in 6 clinics

Israel $20.7 K – 29.4 K in 13 clinics.