Chronic knee synovitis: diagnosis and medical treatment

2021-07-20 04:21 PM

Chronic nonspecific knee synovitis is a common disease in clinical practice, manifested by prolonged pain and swelling of the knee joint, repeated many times but no cause can be found

Chronic non-specific knee synovitis is a common disease in clinical practice, manifested by prolonged swelling and pain of the knee joint, repeated many times but no cause is found, the tests detect the causes. causative agents such as bacterial infections, microcrystalline arthritis, etc., were all negative. This may be the first symptom of a systemic disease, the later stage fully manifests the symptoms of the disease (rheumatoid arthritis, ankylosing spondylitis, Treatment at this stage is treatment. In case of prolonged course (over 06 weeks), treat as rheumatoid arthritis.


Local symptoms: one or two knee joints may be inflamed. The main clinical manifestations: swelling, pain in the knee joint, less heat, obvious redness, may or may not be cocooned with effusion of the knee joint.

Systemic symptoms: little change.


Peripheral blood tests: tests to evaluate inflammation (+): increased erythrocyte sedimentation rate, increased CRP.

RF, anti-CCP can be negative or positive. Patients with positive anti-CCP are likely to progress to rheumatoid arthritis.

HLA-B27 can be negative or positive. HLA-B27-positive patients are more likely to develop ankylosing spondylitis.

Joint fluid test:

Cytology of synovial fluid: the manifestation of chronic nonspecific synovitis.

Bacterial culture: negative.

Staining for AFB, PCR-BK: negative.

Synovial membrane biopsy: through knee arthroscopy, synovial biopsy: chronic nonspecific synovitis.

X-ray of the knee joint: usually no lesions on X-ray in the early stages of erosive lesions (these patients may progress to rheumatoid arthritis).

Magnetic resonance imaging of the knee joint: indicates synovial inflammation, knee effusion, is of little value in diagnosing the disease.

Knee ultrasound: often shows thickened synovial membrane, knee effusion.

Mantoux reaction: negative.

Chest X-ray: normal.

Differential diagnosis

Common bacterial infections

Clinical symptoms: knee joint swelling, heat, redness, obvious pain, the patient has an infection syndrome.

Joint fluid cells: purulent inflammation, degenerated polymorphonuclear leukocytes.

Bacterial culture: positive or not.

X-ray: can see subchondral bone destruction (narrow joint space, bone destruction on both sides).

Joint TB

The knee joint may have a protrusion next to the knee joint.

Synovial fluid cells: can see semi-intermediate cells, bean pulp necrosis.

Fresh synovial smear for AFB: may be positive.

PCR-BK of knee joint fluid: may be positive.

X-ray of the knee joint: images of arthritis: narrowing of the joint space, subchondral bone destruction, in the late stage, the image of soft calcification around the joint.

Hemophilia of the knee joint.

Chronic inflammation after trauma

Mantoux reaction: positive.


Bilan inflammatory biomarkers: negative.

X-ray of the knee joint: there is the asymmetrical narrowing of the joint space, subchondral solidification, bone spurs.


Have a history of trauma.

Joint fluid is pink.

Balanitis: negative.

Microcrystalline arthritis

Cytology of synovial fluid: urate crystals, sometimes with oxalates, pyrophosphates.

Pigmented nodular hairy synovitis

Joint fluid is pink, blood is not clotting.

Synovial membrane biopsy: hemosiderin pigment deposition and multinucleated giant cells.

One-joint rheumatoid arthritis

Synovial membrane biopsies: rheumatoid arthritis-specific lesions.

The initial treatment is symptomatic. In case of prolonged course (over 06 weeks) after excluding other causes, treatment such as rheumatoid arthritis. Combine symptomatic (anti-inflammatory, analgesic) and slow-acting antirheumatic drugs at the outset. Symptomatic drugs can be reduced or stopped altogether. The basic treatment drugs are often used early, long-term.

Symptomatic treatment

Non-steroidal anti-inflammatory drugs

Indications: stage of moderate arthritis or replacement of corticosteroids. Be careful to avoid side effects of the drug.

Choose one of the following drugs (note absolutely do not combine drugs in the group because they do not increase the treatment effect but have many side effects):

Diclofenac (Voltaren) 50mg tablet: 2 tablets/day divided into 2 or 75mg tablets x 1 tablet/day after a full meal. 75mg/day intramuscular injection can be used for the first 2-3 days when the patient is in great pain, then switch to oral.

Meloxicam (Mobic) tablet 7.5mg x 2 tablets/day after eating or as an intramuscular injection 15mg/day x 2-3 days if the patient has a lot of pain, then switch to oral route.

Piroxicam (Felden) 20mg tablet or tube, take 1 tablet/day orally after eating or inject 1 ampoule intramuscularly for the first 2-3 days when the patient has a lot of pain, then switch to oral.

Celecoxib (Celebrex) tablets 200mg dose 1 to 2 tablets / day after a full meal. Should not be used in patients with a history of cardiovascular disease and with greater caution in the elderly.


Short-term systemic glucocorticoid therapy, markedly improved inflammation.

Indications: patients who do not respond to non-steroidal anti-inflammatory drugs and severe inflammation.

Dosage and usage: In severe cases of inflammation, a mini bolus can be used: 80-125mg intravenous infusion of methylprednisolone mixed in 250ml of physiological salt for 3-5 days. After this dose, maintain oral administration of 1.5-2mg/kg/24 hours based on prednisolone. Discount 10%/week. When in high dose divided drink 2/3 morning, 1/3 afternoon.

When at a dose <40mg/day orally once a day at 8 am, after meals. Usually, after 1-2 months can be replaced with non-steroidal anti-inflammatory drugs.

Topical glucocorticoid: in case of prolonged inflammation, inject the knee joint with Depo-Medrol 40mg/1ml, Disprospan 4mg/1ml. Injected in a sterile room by a musculoskeletal specialist.

Each course of injection at one knee joint: 2 injections 7-10 days apart. After 6 months, the injection can be repeated if indicated.

Pain relievers

Indicated according to the ladder diagram of the World Health Organization. Commonly used drugs:

Paracetamol: 2-3 grams/day.

Paracetamol combined with codeine (Efferalgan Codein): 4-6 tablets/day.

Paracetamol combined with dextropropoxyphene (Di-antalvic): 4-6 tablets/day.

Basic treatment

Synthetic antimalarials

Hydroxychloroquine (Plaquenil 200mg tablet), or chloroquine 250mg/day (250mg tablet).

Contraindications: pregnant patients, people with G6PD deficiency, or liver damage.

Side effects: anorexia, vomiting, epigastric pain, darkening of the skin, dry skin, reticular inflammation in the retina. need to check vision, ophthalmoscopy every 6 months.


Indications: this is the drug of the first choice.

Contraindications: leukopenia, liver and kidney failure, chronic lung damage.

Undesirable effects: often mouth ulcers, vomiting, nausea. May cause liver and marrow cytotoxicity.

Dosage: 10-20mg/week, intramuscularly or orally. Usually started with 10mg taken once a week on a certain day of the week. The drug takes effect after 1-2 months. The dose can be adjusted according to the response of the patient. However, methotrexate resistance may occur with prolonged use. Do not use doses less than 5mg/week. Often combined with synthetic antimalarials.

Limit the side effects of methotrexate by supplementing with folic acid, the dose is equal to the dose of methotrexate (5mg tablets, 02 tablets/week divided into 2 days a week with a dose of 10mg methotrexate/week.


Indications: used for patients with positive HLA-B27 in case the disease tends to turn into ankylosing spondylitis.

Dosage: 1-2 grams/day.

Side effects: gastrointestinal disturbances, anorexia, skin rash, bullae, mouth ulcers, proteinuria, nephrotic syndrome, thyroiditis, thrombocytopenia, leukopenia, hemolysis, ...

Arthroscopic repair joints remove deformities.

Physical rehabilitation.

Examination and alignment of the knee joint.


Instruct patients on regular drug treatment and monthly checkups to monitor clinical and laboratory tests: peripheral blood cells, erythrocyte sedimentation rate, CPR, liver, and kidney function, to adjust drugs early detection of disease progression: into rheumatoid arthritis, ankylosing spondylitis.

Monitoring to prevent unwanted effects of the drug.

Instruct the patient to practice avoiding adhesions and deformity of the knee joint.