What Is Septic Arthritis?

Purulent arthritis is a type of arthritis that is directly infected by purulent bacteria and causes joint destruction and loss of function, also known as bacterial arthritis or septic arthritis. It can occur at any age, but it is more common in children, elderly people with frailty, and chronic joint disease. The majority of men are males, and the male to female ratio is 2 to 3: 1. Most affected are single large joints of the limbs, such as the hip, knee, and elbow. If it is a firearm injury, it depends on the location of the injury. Generally, the incidence of knee and elbow joints is high.

Basic Information

nickname

Bacterial arthritis, septic arthritis

Visiting department

orthopedics

Multiple groups

Child, elderly frail and chronic joint disease, male

Common locations

Hip, knee and elbow

Common causes

Staphylococcus aureus, followed by Streptococcus, Pneumococcus, E. coli, Haemophilus influenzae, etc.

Common symptoms

High chills, severe systemic symptoms, and convulsions in children due to high fever. Local swelling and pain and obvious tenderness, etc.

Causes of septic arthritis

More than 50% of the pathogens are Staphylococcus aureus, followed by Streptococcus, Pneumococcus, Escherichia coli, Haemophilus influenza, and so on. Infection is most common with blood-borne infections. In addition, bacteria can enter the joints directly from joint cavity puncture, surgery, injury or infection of adjacent tissues. Hematogenous infections can also be complications of acute fever, such as measles, scarlet fever, pneumonia, etc., which are more common in children. Traumatic causes are mostly open injuries, especially if the wound is not properly treated. Adjacent infections, such as acute suppurative osteomyelitis, can spread directly to the joints.

Clinical manifestations of septic arthritis

The main symptom of septic arthritis in the acute phase is the manifestation of poisoning: the patient has a sudden chills and high fever, the systemic symptoms are severe, and pediatric patients can cause convulsions due to high fever. Acute inflammation such as local swelling and pain and obvious tenderness. Synovial fluid increases and fluctuates, which is more pronounced in superficial joints such as the knee joint, with sacral floating signs. Patients often place the knee joint in a semi-flexed position to relax the joint capsule to reduce tension. If long-term flexion, joint flexion contracture will occur, a little pain in the joint, and protective muscle spasm.

Monoarthritis

Adults involve the knee joints more, children involve the hip joints, followed by the ankle, elbow, wrist and shoulder joints, and hand and foot joints are rare.

2. Inflammatory manifestations

The joints are red, swollen, hot, and painful, with tenderness and limited movement. When deep joints such as the hip joint are infected, the swelling and pain are local, but the red heat is not obvious.

3. Symptoms of poisoning

Sudden onset of illness, symptoms of systemic poisoning such as chills, fever, fatigue, and poor appetite.

4. Primary infection

Such as pneumonia, urethritis, salpingitis, salamander and so on.

Septic arthritis examination

Laboratory inspection

(1) Blood routine The total number of white blood cells is increased and neutrophils are increased. The erythrocyte sedimentation rate increases, and the blood culture can be positive.

(2) Joint synovial fluid examination should be carried out as soon as possible. Synovial fluid is serous or purulent, the total number of white blood cells is often greater than 50 × 10 ⁹ / L, and neutrophils are greater than 80%. Gram stain can find bacteria. Bacterial culture is positive. If negative, anaerobic bacteria culture should be repeated and drug sensitivity test should be performed.

(3) Arthroscopy can directly observe the structure of the joint cavity and take synovial fluid or tissue inspection.

2.X-ray inspection

During X-ray examination, the joint capsule swelled due to the increase of joint fluid in the early stage, the gap widened, and the bone end gradually decalcified. If the articular cartilage is damaged, the joint space becomes narrow. Sometimes it can be complicated by epiphyseal slippage or pathological dislocation. At a later stage, articular surface subchondral bone was reactive hyperplasia, bone hardening, and density increased. Finally, the articular cartilage is completely dissolved, the joint space disappears, bony or fibrous rigidity, or pathological dislocation.

Diagnosis of septic arthritis

The diagnosis is mainly based on medical history, clinical symptoms and signs. Patients with suspected hematogenous purulent arthritis should undergo blood and joint fluid bacterial culture and drug sensitivity tests. X-ray examination only showed swelling of the joint; bone decalcification may occur later, joint space narrow due to cartilage and bone destruction, and joint bony or fibrous stiffness and deformity may occur in the later stage, with new bone hyperplasia, but dead bone Formation is less.

Purulent Arthritis Treatment

General treatment

(1) Rehydration to correct water and electrolyte disorders.

(2) Use skin traction or plaster support to fix the affected limb in the functional position.

(3) Active exercise;

(4) Joint puncture and drainage, rinse with normal saline.

2. Drug treatment

(1) Use of effective antibiotics In the acute phase, intravenous administration is required. After infection control, oral administration is required.

(2) Joint puncture Pumping, flushing, and injecting effective antibiotics until the joint has no fluid.

3. Surgical treatment

(1) Early surgical treatment should be done to prevent joint infection.

(2) Local treatments include joint puncture, fixation of the affected limb, and surgical incision and drainage. If it is closed, the joint fluid should be removed as much as possible, and then injected with antibiotics once a day. If it is pus or infection after injury, it should be cut open and drained as early as possible. The wound can also be treated with antibacterial drug drip drainage or local wet dressing to control infection as soon as possible. The affected limb should be properly fixed or pulled to prevent the spread of infection and maintain a functional position. Prevent contracture deformities, or correct existing deformities. Once the acute inflammation subsides or the wound heals, start the automatic and mild passive movement of the joint to restore joint mobility. However, do not move too early or too much to prevent recurrence of symptoms.

Patients should pay attention to during recovery: pay attention to rest, moderate labor, and work and rest. Keep your skin clean and hygienic to prevent infection. Follow your doctor's advice and take your medicine on time. Regular outpatient follow-up.