Acute septic arthritis in children

Introduction to acute septic arthritis in children Acute suppurative arthritis (acutesuppurativearthritis) is more common in the knee, hip, shoulder, and elbow joints. In infants and young children, it is often closely related to osteoporosis of the metaphysis. However, many cases are invaded into the joint synovium by blood. And caused, in the end, can also destroy the osteophytes and secondary osteomyelitis. basic knowledge The proportion of illness: 0.021% Susceptible people: children Mode of infection: non-infectious Complications: ischemic necrosis

Causes of acute septic arthritis in children

(1) Causes of the disease

This disease is often complicated by bacteremia or sepsis of Staphylococcus aureus. The common pathogen is Staphylococcus aureus. Occasionally, Streptococcus, Escherichia coli, Pneumococci or Meningococcus can be found. Special care should be taken during femoral vein puncture to avoid accidental entry into the hip joint. There are three ways in which bacteria invade the joint:

1. Blood-borne infections from the affected joints such as carbuncles, bruises, upper respiratory tract infections or otitis media, bacteria invade the bloodstream, and stay in the synovial membrane.

2. Direct invasion from nearby lesions such as osteomyelitis spread to adjacent joints (osteomyelitis of the upper femur of the baby can often be complicated by hip septic arthritis.

3. Direct contamination of joint puncture, exploration of surgery or other accidental injuries.

(two) pathogenesis

Bacterial invasion of the joint causes synovial congestion, exudation and other acute inflammation. The exudate is serous in the early stage and quickly turns into serous fibrinous or purulent. When the joint capsule is highly dilated, it can cause pathological dislocation, which is more common in Hip joint, synovial edema, congestion, exudate to swollen joints, exudate in the synovial cavity is initially thin and turbid, of which white blood cells can reach 50,000/mm3, joint fluid smears can find bacteria, sugar in synovial fluid The content is lowered and the protein is increased.

After a few days, if the inflammation is not controlled, the joint glassy cartilage can be quickly eroded. The staphylococcal pus can dissolve the glassy cartilage within 3 to 24 hours. The cartilage is dissolved due to the action of the enzyme in the pus. This enzyme may be from it. Released from polymorphonuclear cells, autolysis changes faster when the body temperature increases, cartilage damage begins at the close contact of the upper and lower articular surfaces, and the following joints are often in the middle of the negative focus, and the synovial membrane is gradually replaced by granulation tissue. The exposed bone surface also grows granulation tissue, and the infection can spread to the bone tissue, whereby the joint can undergo fibrotic or bony fusion.

Acute septic arthritis prevention in children

Actively prevent and treat infectious diseases, strengthen nursing, enhance physical fitness, prevent trauma and so on.

Acute septic arthritis complications in children Complications ischemic necrosis

The hydrostatic pressure in the hip joint is increased. After the joint is filled, the blood supply can cause avascular necrosis of the femoral head. On the X-ray photograph, the center of the femoral head can disappear. In this case, the load should be avoided and the double page can be used. Hip herringbone plaster fixed, can be walked by the disease after inflammation control, can be protected with abduction brace for 1 to 2 months, flat hip is a common sequela of avascular necrosis of the femoral head, femoral head tarsal stop growth, and femur The trochanter bones continue to develop, and a certain degree of hip varus is produced in the future. If the hip varus is severe, it can be corrected by abducting osteotomy at the upper end of the femur.

Unequal length of the lower extremities is also a common complication. For the long side, an epiphyseal block is performed at an age of growth potential.

Pathological dislocation is caused by increased intra-articular pressure. Surgical drainage should be performed for this complication, and the reduction should be performed at the same time, or orthopedic surgery should be performed half a year after the inflammation subsides.

Symptoms of acute septic arthritis in children Common symptoms Leukocytosis Joint swelling Soft tissue swelling Joint pain Joint effusion Irritability Appetite Loss

Generally, there are manifestations of sepsis or traumatic history, such as fever, rapid pulse, increased white blood cells, swelling of the affected joints, pain and limited mobility. Most of the affected limbs are in a semi-flexed position. X-ray films show joint capsule bulging and surrounding soft tissue swelling. If the treatment is not timely, the glassy articular cartilage surface will soon be destroyed and degenerative. The joint is filled with pus and the muscle spasm can cause pathological dislocation, which can cause deformity and limited activity. Most cases have a history of trauma or infection. Such as otitis media or skin infections, the onset is more urgent, the main complaint is the local joint pain, the following limbs and joints are involved in lameness, the sick child quickly can not walk because of weight-bearing pain, in addition to irritability, loss of appetite, fever, body temperature Up to 40 °C, signs of inflammation of the joint local temperature increase, swelling, joint effusion, due to protective muscle spasm, the joint is in a semi-flexed state, extensive tenderness along the joint line during palpation, automatic or passive joints are painful Because of the false sputum.

The systemic response of newborns and infants is mild or absent, and the only signs are joint swelling and flexion contracture.

Joint pain, swelling, limited mobility, systemic symptoms of infection and related tests can be conceived in this disease, and then confirmed by joint puncture, joint puncture is best carried out under strict aseptic conditions in the operating room, with 16-18 Lumbar puncture with core, hip joint puncture using the anterior joint approach, the femoral artery as a marker, at the midpoint of the inguinal ligament, 1.5 cm below the femoral artery outside the inguinal ligament, needle inward 45 ° ~ 60 ° thorn Into, when there is a sense of falling into the joint capsule, stop the needle, be careful not to damage the articular cartilage surface to prevent the infection from spreading into the bone. Before the puncture, carefully check the needle and use a core needle to prevent the needle or cellulose from clogging. Needle.

Examination of acute septic arthritis in children

Joint puncture can obtain turbid liquid or viscous pus, the number of cells exceeds 4×10 ⁹ /L (4000/mm3), mainly with neutral polynuclear cells, fibrin increases in joint fluid, and solidifies quickly after extraction. The content is lower than that in the blood, and the pathogenic bacteria can be seen by smear Gram staining.

X-ray examination of acute septic arthritis: early manifestation of joint capsule effusion expansion, if the hip joint will have the femoral head displaced or even out, the infection persists, bone decalcification and joint space narrowing can be seen .

Diagnosis and diagnosis of acute septic arthritis in children

diagnosis

If the amount of joint fluid is small or the pus is thin, you can first inject 1ml of normal saline, then pump it again. The joint fluid should be sent to culture and smear to identify the pathogenic bacteria. This is not only helpful for diagnosis, but also suitable for selection. The medicine is also helpful.

At the beginning of the onset, the joint fluid may be serous and bloody. After a few days, the turbidity and the number of cells increase (generally 15,000 to 20,000/mm3), the proportion of neutral polymorphonuclear leukocytes increases, the sugar in the joint fluid decreases, and the average blood glucose is lower. Low 50mg/100ml, acidic precipitation method to check mucus protein, can be found that the quality of the protein is not as normal.

Small babies, especially newborns, suffer from sepsis, often without fever, but there will be irritability, refusal to eat, and even weight loss. At this time, the possibility of sepsis should be thought of, and repeated infections of bone and joints should be observed repeatedly.

Differential diagnosis

1. Tuberculous arthritis: There are many primary lungs, tuberculin test is positive, and the symptoms are mild.

2. Joint blood: such as hemophilia joint blood, a history of bleeding, hematology can be used as the final basis.

3. Synovitis: Temporary synovitis caused by virus or trauma, systemic symptoms are mild, local swelling is also light, if there is joint fluid can be extracted, but no suppuration.

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