Acute hematogenous osteomyelitis is also known as acute osteomyelitis because most cases are inflammations caused by septic bacteria attacking the connective tissue in the bone marrow via the bloodstream. In a few cases, the infection spreads from adjacent soft tissues or is secondary to an open fracture. If left untreated, the bone structure can be destroyed and disability can occur, or the infection can spread and become life-threatening. In some cases, the disease may become chronic, with a long course, and may affect the nutrition and growth of children, as it is most often seen in children.
The causative organisms are often hemolytic Staphylococcus aureus, and in recent years there are also more virulent hemolytic white staphylococci, occasionally Salmonella, pneumococci or other septic bacteria, most of which are resistant to penicillin and streptomycin. Common primary lesions are pustules, gingival abscesses and upper respiratory tract infections.
The preferred sites of osteomyelitis are the lower femur and upper tibia, followed by the upper femur, humerus and distal radius. However, it can occur in all other bones. Signs and symptoms vary with the severity of the infection, the location, the extent of inflammation, the duration of the disease, the age of the child, and the degree of resistance.
They can be broadly classified into 3 types.
1, septicemia type
This type accounts for about 80%. Systemic symptoms are the manifestation of acute sepsis, there may be high fever, coma, delirium and other symptoms. Even toxic shock occurs. Because of blood dissemination, it is often accompanied by serious infections in other sites, such as purulent pericarditis, pneumothorax, brain abscess, etc. Severe cases may be complicated by migratory lesions in the heart, lungs, liver, kidneys and other organs, leading to functional impairment of multiple organs. Local symptoms include persistent severe pain, fear of movement, pressure pain, axial percussion pain, and circumferential swelling of the affected limb. In a few cases, systemic symptoms are the main manifestation, but the local signs of the affected bone are very late, so early detection of bone lesions is needed.
2.Complicated arthritis type
This type is mostly in newborns and small infants. The systemic symptoms are often mild and the body temperature is not high, but there is irritability, refusal to eat and weight gain. The lesions are mostly found on the upper femur, upper tibia or upper humerus. Since the epiphysis is included in the joint capsule or the destruction of the epiphysis affects the basis of epiphyseal plate attachment, the inflammation spreads easily into the joint and some epiphyseal slippage or destruction occurs, which affects the future development.
3.Limited destruction or bone abscess type
This type is mostly seen in school-age children, with mild clinical symptoms, localized swelling and pain, and limited movement of nearby joints. Individual children may develop sympathetic joint effusion.
Examination items.
1.X-ray examination
X-ray examination within 14 days after the onset of the disease often shows no abnormal findings, and the appearance of X-ray manifestation can be delayed to about 1 month in cases with antibiotics. it is difficult to show bone abscesses smaller than 25px in diameter on X-ray examination, so the early X-ray manifestation is laminar periosteal reaction with sparse bone in the epiphysis. Scattered worm-like bone destruction in the epiphyseal region with extension into the medullary cavity appears on X-ray only when a small bone abscess merges into a larger abscess, when the dense bone becomes thin and irregular changes in the inner and outer layers appear in sequence. The bone destruction results in the formation of dead bone, which may be large or small. Small dead bone may appear as a shadow of increased density, located in the pus cavity, and completely free from the surrounding bone tissue. Large dead bones may be whole segments of osteonecrosis, with increased density and no trabecular structures visible. In a few cases, pathological fractures are present.
2.CT examination
It can detect subperiosteal abscesses in advance, but it is still difficult to show small bone abscesses.
3.MRI examination
It can detect the inflammatory abnormal signal in the long bone epiphysis and bone stem at an earlier stage, and can also show the subperiosteal abscess. Therefore, MRI examination is significantly better than X-ray and CT examination.
4.Radionuclide bone imaging
The vasodilatation and increase of blood vessels at the site of the lesion make 99mTc concentrated at the early stage of the lesion in the epiphysis, and the positive result is usually available 48h after the onset of the disease. Radionuclide bone imaging can only show the location of the lesion, but cannot make a qualitative diagnosis, so this test is only of indirect diagnostic value.
1. Acute hyperthermia and toxemia manifestations.
2. Severe pain in the long bone epiphysis and reluctance to move the limb.
3. There is a distinct pressure area in the area.
4, Increased white blood cell count and neutrophil ratio. Local stratified puncture has diagnostic value.
Etiological diagnosis lies in obtaining the causative organism. Blood culture with stratified puncture fluid culture is of great value. Repeated blood cultures are required to increase the positive rate.
Early treatment is necessary
After taking the specimen and sending it for bacterial culture, give antibiotics immediately and do not wait for the culture results. In recent years, high-dose antibiotics are administered intravenously. When the causative organism and the sensitive antibiotic are clearly identified, the effective drug is immediately replaced. Intravenous administration is given for 2 to 3 weeks and can be changed to oral antibiotics for 2 to 3 weeks after the infection is controlled. The affected limb is immobilized in a functional position with a cast or skin traction to ensure rest, reduce pain and prevent the spread of infection and pathological fracture. Systemic supportive therapy should not be neglected, such as antipyretics, fluid replacement, fresh blood transfusion, high protein diet and multivitamins. In severe cases of systemic toxicity, adrenocorticosteroids may be used as appropriate.
Acute osteomyelitis often requires surgical drainage. Early cases within 24 hours of onset may be cured by conservative therapy if the temperature drops and pain is relieved after adequate and effective treatment. Delayed or delayed diagnosis, such as severe systemic and local symptoms, requires surgical drainage if there is pus on the puncture. Surgical treatment includes incision and drainage with bone drilling or window decompression. Two silicone tubes may be placed in the incision or medullary cavity, one for irrigation with a drip of antibiotic solution and the other for drainage. Wounds with low pus accumulation can be sutured after flushing with antibiotic solution, and half of them can get a one-stage wound healing.