Acute hematogenous osteomyelitis

Introduction to acute blood-borne osteomyelitis Acute hematogenous osteomyelitis (acute hematogenous osteomyelitis) is also called acute osteomyelitis, because in most cases, the purulent bacteria invade the inflammation caused by connective tissue in the bone marrow. A small number of infections from adjacent soft tissue spread or secondary to open fractures, if not treated in time, will cause bone structure damage, disability, and even spread and life-threatening. Some cases can be converted into chronic lesions, and the course of disease is long. Because it is more common in children, it may affect the nutrition and growth of children. basic knowledge The proportion of illness: 0.003% Susceptible people: more common in children Mode of infection: non-infectious Complications: septic arthritis, fracture, sepsis, suppurative osteomyelitis

Cause of acute blood-borne osteomyelitis

The disease occurs mostly in children and adolescents. It starts at the metaphysis of the long bones. The bacteria in the clusters stagnate here. After the lesion is formed, the abscess is surrounded by bone. The drainage is not good, and there are many severe toxemias. After that, the abscess expands in different directions depending on the local resistance.

(1) Causes of the disease

The pathogen is often hemolytic Staphylococcus aureus. In recent years, it has also toxic Hemolytic Staphylococcus aureus. Occasionally, Salmonella, pneumococcal or other pyogenic bacteria are found. Most of them are resistant to blue and streptomycin. The primary lesions were pustules, gingival abscesses and upper respiratory tract infections.

(two) pathogenesis

The occurrence of osteomyelitis, the size of bacterial virulence is an external factor, systemic or local bone resistance is an intrinsic factor, there are many terminal small arteries at the end of the long bone, the circulation is rich, the blood flow is slow, the bacteria are easy to breed, and some bacteria For example, staphylococci often aggregate into clusters, forming embolism in small arteries, blocking the end of blood vessels, leading to local tissue necrosis, which is conducive to bacterial growth and infection. Clinically, local tissue damage caused by sprains and contusions is often osteomyelitis. The indirect cause of the occurrence.

48 hours after the start of infection, the bacterial toxin can damage the capillary circulation of the metaphysis, and generate pus at the metaphysis. After entering the periosteum through the Harvard system and the Volkman tube, the periosteum is peeled off, resulting in bone destruction, necrosis and thus The induced repair response (bone hyperplasia) coexists at the same time. The early stage is mainly destruction and necrosis. The cortical bone inner layer receives the blood supply from the metaphysis. After the blood supply is damaged, the bone is necrotic. The granulation tissue separates it from the surviving bone. Forming a dead bone piece, the periosteum reacts to form a new bone called involucrum, which infects the infected bone and necrotic bone. After the capsule appears, the defect forms cloaca and sinus, drains the pus, and later accumulates bone. the Lord.

After the formation of intraosseous infection, the surrounding area is bone, the drainage is not smooth, and there are many severe toxemia manifestations. Later, as the abscess expands, the infection spreads along the direction of less local resistance.

Abscess spread

(1) The abscess spreads to the long bone end, because the ability of the epiphyseal plate to resist infection is strong, the pus does not easily penetrate the tarsal plate into the joint cavity, and diffuses into the medullary cavity, causing the bone marrow cavity to be involved, and the pressure of the pus in the medullary cavity is increased. Then spread along the central tube to the subperiosteal layer to form a subperiosteal abscess.

(2) The pus breaks through the metastatic bone of the metaphysis, and penetrates into the periosteum to form a subperiosteal abscess; when the pressure is further increased, the periosteum breaks into the soft tissue and can also invade the bone marrow cavity along the Harvard tube.

(3) penetrate the joints, cause septic arthritis, pediatric epiphyseal plate is a natural barrier against infection, abscess is not easy to enter the joint cavity, but the adult tarsal plate is not resistant, it is easy to have arthritis, such as the metaphysis is located in the joint capsule Inside (such as the femoral neck in the hip capsule), the abscess can also penetrate the metaphyseal cortex into the joint to form septic arthritis.

2. Bone nutrition

The part of the bone marrow cavity is supplied by the nourishing blood vessel, and the cortical part close to the periosteum is supplied by the subperiosteal small blood vessel network. When the periosteum is lifted by the abscess, the cortical bone loses the blood supply from the periosteum, which seriously affects the circulation of the bone and causes osteonecrosis. After the pus enters the bone marrow and the central canal, the nourishing blood vessels passing through the lumen form thrombus and pustules due to inflammation, and the blood supply in the bone is blocked, causing osteonecrosis, distribution and size of the necrotic area, depending on the ischemic range. In severe cases, the entire bone necrosis can occur. Due to periosteal dissection, the deep periosteal cells of the periosteum are inflammatoryly stimulated to generate a large amount of new bone, which is wrapped around the dead bone to form a cladding, which can replace the diseased bone to support the pus. From this, small pieces of dead bone can be absorbed or discharged through the sinus, large pieces of dead bone can not be discharged or absorbed, the dead space can not be closed, the wound is not cured for a long time, becoming chronic osteomyelitis.

Acute blood-borne osteomyelitis prevention

Mostly caused by blood-borne disseminated infection, it should be actively prevented to treat sepsis; actively prevent and treat various infectious diseases of skin and mucous membranes; actively prevent upper respiratory tract infections, etc., focusing on patient care, including pre-operative and post-operative care:

First, preoperative care

1, acute osteomyelitis with high fever, chills, anorexia, irritability and other symptoms, pain, swelling, limited mobility is a local symptom, should be treated according to critical care, high temperature application of physical cooling and drug cooling, alcohol rubbing bath, etc. .

2, systemic support therapy can not be ignored, such as fever, rehydration, calculation of intake, in order to maintain water and electrolyte balance, can lose fresh blood when anemia, give a high protein diet and add a variety of vitamins.

3, the skin must be cleaned before surgery to remove skin dirt, skin should avoid damage to the skin.

4, diet management: generally 8 hours before surgery fasting, 4 hours of water.

5, preoperative examination and coordination: preoperative examination is extremely important for diagnosis and development of treatment plans, nursing staff should closely cooperate, such as urged parents to leave urine specimens, escort children to do X-ray film, special inspection preparation and do Good skin test and so on.

6. Psychological care: After the child arrives at the hospital, the nurse should have a high degree of compassion and responsibility for the child, carefully care for the child, establish a friendly relationship with the child, and talk to the parents to let the parents know the general disease knowledge and The nursing method enables parents and children to have a sense of trust in the medical staff, thereby improving the mood of the child, improving confidence, and promoting physical and mental recovery of the child.

Second, postoperative care

1. Observing vital signs: Most children undergo general anesthesia during pediatric surgery. After returning to the ward, they should generally go to the supine position and head to one side to prevent vomiting from aspiration, keep the airway open, and measure vital signs every 30 minutes. Once, until the general anesthesia is awake.

2, after the operation of easy to digest, nutritious food, due to brakes in bed activities, easy to cause constipation, give more crude fiber food, drink more water, eat more fruits and vegetables to prevent constipation.

3, the affected limb is fixed with plaster cast, which is beneficial to relieve pain and prevent fracture, but touch the bone protrusion. If the pain is obvious, it indicates that there is gypsum compression, it needs to be treated in time, and keep the bed clean and dry, pay attention to massage the skin of the compression site. To prevent the occurrence of hemorrhoids, observe the blood circulation at the distal end of the limb, pay attention to skin color, temperature, feeling, pain and swelling.

4, the bone marrow cavity into the two silicone tube continuous irrigation and drainage of exudate, can be washed with gentamicin in normal saline, the 24-hour flushing solution should be evenly dripped, the amount of infusion and the amount of fluid to be recorded in detail, If the difference is large, there may be blockage of the output tube, use physiological saline to make it smooth, observe the changes of drainage, smell, color, change the sterile drainage bottle daily, and observe whether the appearance of the wound dressing is clean, extubation Indications: 1 drainage fluid clear; 2 limb swelling subsided; 3 children with normal body temperature can be extubated according to the general condition of the child.

5, functional exercise: early injury and extremity muscle relaxation and contraction activities, to prevent muscle atrophy and joint adhesions, in addition to continued muscle relaxation and contraction exercise in the late stage, the range of activities can be extended to all major joint-based comprehensive functional exercise.

Acute hematogenous osteomyelitis complications Complications septic arthritis fracture sepsis suppurative osteomyelitis

Acute blood-borne osteomyelitis has a high mortality rate (about 25%) in the past, but due to further understanding of the disease in recent years, early diagnosis and active treatment, the application of appropriate antibacterial drugs and comprehensive therapy, the mortality rate has been greatly reduced (about 2%).

Due to bone damage caused by bone infection, the formation of dead bone, often turned into chronic suppurative osteomyelitis, and even various complications, affecting function, common complications are:

(a) septic arthritis.

(B) pathological fractures.

(3) Limb growth disorders, such as osteophyte destruction, affected limb length, affected limbs become shorter; or due to inflammation near the epiphysis, blood supply is abundant, causing the epiphysis to grow faster, and the affected limb is slightly longer, sometimes due to partial involvement of the epiphysis , the formation of abnormal growth, such as knee varus or eversion.

(4) Joint contracture and rigidity.

(5) Traumatic osteomyelitis often has delayed fracture and disconnection due to infection, and limited joint activity.

(6) If the timely and effective treatment is not carried out in the acute phase, or the bacterial virulence is strong, sepsis or sepsis may be complicated, and the seriousness may endanger the patient's life.

(7) The risk of recurrence of osteomyelitis is related to the location of the infection and whether it is treated promptly and effectively. The recurrence rate of osteomyelitis in the tibia can be as high as 50%, involving the proximal femur, proximal and distal tibia. The recurrence rate of osteomyelitis in the metaphysis is 20% to 30%, while the distal humerus, the upper limb bone and the spinal inflammatory infection have a better prognosis and are easy to heal. The recurrence rate of children with acute osteomyelitis after one year of treatment is 4%.

Acute blood-borne myeloinflammation symptoms Common symptoms chills high fever soft tissue swelling irritability, loss of appetite, meningeal irritation, bone destruction, severe pain, severe pain

1. Systemic symptoms are acute, and there are obvious symptoms of systemic poisoning at the beginning. There are many relaxation and hyperthermia, up to 39~40°C, sometimes with chills, rapid pulse, dry mouth, loss of appetite, headache, vomiting, etc. Meningeal irritation, children with irritability, severe cases may have sputum, coma and other sepsis performance, retrospective history, and some have infections.

Acute osteomyelitis caused by trauma, in addition to serious complications or a large number of soft tissue injuries and infections, generally systemic symptoms are mild, infection is limited, and few sepsis occurs, but should be alert to the risk of anaerobic infection.

2. Local symptoms in the early stage have local severe pain and pulsating pain, muscles have protective tendons, fear of moving the affected limbs, children often put their limbs in a protective posture to relieve pain, the skin temperature of the affected part is increased, and there is deep tenderness, but In the early stage, there was no obvious swelling. After a few days, the local skin edema and redness were the manifestations of subperiosteal abscess. After the abscess penetrated the periosteum into the soft tissue, the pressure was relieved and the pain was relieved, but the symptoms of soft tissue involvement were obvious, local redness and swelling. , heat, tenderness, and fluctuations, pus into the bone marrow cavity after the bone, the entire limb pain and swelling, osteoporosis due to inflammation, often accompanied by pathological fractures.

Acute blood-borne osteomyelitis

The main methods of examination for this disease are as follows:

1, laboratory inspection

In patients with acute suppurative osteomyelitis, white blood cells and neutrophils are significantly increased in the early stage, and the white blood cell count is increased, generally above 10×10 9th power/L, and neutrophils may account for more than 90%. Anemia and erythrocyte sedimentation rate increase, the positive rate of early blood bacterial culture is 50% to 75%. Usually, blood positive culture results can be obtained 24 hours after infection. Local bone puncture can extract pus, smear can find bacteria to confirm diagnosis, blood and While the pus bacteria are cultured, they should be tested for bacterial drug sensitivity in order to select effective antibiotic treatment.

2, bacteriological examination

Blood culture can obtain pathogenic bacteria, but not every culture can get positive results, especially those who have used antibiotics have lower blood culture positive rate, and take blood every 2 hours during the cold and high fever period. Three times, the blood culture positive rate can be increased, and the pathogenic bacteria obtained should be tested for drug sensitivity in order to adjust the antibiotics.

3, local abscess wind puncture

The selected inner core puncture needle is pierced at the most obvious dry end of the tenderness, and penetrates deeply while inhaling. Do not penetrate into the bone once, so as to avoid bringing bacteria with simple soft tissue abscess into the bone, and extracting turbid liquid or bloody liquid can be used. Smear examination and bacterial culture, smear found in most pus cells or bacteria can be clearly diagnosed, any nature of the spur liquid should be used for bacterial culture and drug sensitivity test.

4, X-ray inspection

X-ray examination within 14 days after onset is often found to be abnormal. The time of X-ray manifestation in cases with antibiotics can be delayed to about 1 month. X-ray examination is difficult to show bone abscess less than 1 cm in diameter, so early X The line manifests as a lamellar periosteal reaction and sparse bone at the metaphysis. When the smiling bone abscess merges into a large abscess, the dry bone area will be scattered on the X-ray film. The dead bone can be large or small. The small dead bone is characterized by increased density and shadow. It is located in the abscess cavity and completely free from the surrounding bone tissue. The large dead bone can be used for osteonecrosis of the segment. The density is increased and the trabecular structure is visible. There are pathological fractures in a few cases.

5, CT examination

Subperiosteal abscess can be found in advance, and it is still difficult to display small bone abscesses.

6, MRI examination can be found earlier in the long bones of the metaphysis and the backbone of inflammatory abnormal signals, can also show subperiosteal abscess, therefore, MRI is significantly better than X-ray and CT examination.

7, radionuclide bone imaging

The vasodilatation and increase of the lesion site make the lesions concentrated at the end of the dry bone at the early stage of 99m sputum generally have a positive result 48 hours after the onset of the disease. The radionuclide bone imaging can only show the lesion, but can not be made. Qualitative diagnosis, so this test only has the value of indirect help diagnosis.

Diagnosis and diagnosis of acute blood-borne osteomyelitis

diagnosis

In the diagnosis, two problems should be solved, that is, the diagnosis of the disease and the diagnosis of the cause, the diagnosis should be early, because the X-ray appearance is very late, so the X-ray examination results can not be used as the diagnosis basis. For those who have the condition, MRI examination can be obtained. The diagnosis of osteomyelitis is a comprehensive diagnosis. Anyone with the following manifestations should have the possibility of acute osteomyelitis:

1. Rapid hyperthermia and toxemia performance.

2. The long bones are painful and do not want to move the limbs.

3. There is an obvious tenderness area there.

4. The white blood cell count and the proportion of neutrophils are increased, and local stratified puncture has diagnostic value.

5. The cause of the diagnosis lies in the acquisition of pathogenic bacteria. Blood culture and stratified puncture fluid culture have great value. In order to increase the positive rate, blood culture should be repeated.

6. X-ray showed local bone sparse, periosteal reaction, bone destruction, because the signs of bone destruction often appeared after 2 weeks of onset, so X-ray examination is not helpful for the early diagnosis of acute hematogenous osteomyelitis, foreign scholars It is believed that the X-ray can show soft tissue swelling, but it may occur at least 10 to 14 days after local bone destruction or periosteal reaction.

7. The positive rate of early diagnosis of bone scan is high, which can show local nuclear thick staining. 99m Tc scan can make 90%~95% of patients diagnosed 24 to 48 hours after the disease. It is suggested that patients who are suspected of this disease should not only be photographed. X-ray plain film, bone scan, for the need for surgical drainage (including spinal or pelvic infection), lesions invaded the backbone of the infection, antibiotics for 48 hours ineffective, also need to perform MR examination.

A clear diagnosis and appropriate treatment should be made early in the onset of the disease to avoid the development of chronic osteomyelitis. According to the literature, diagnosis and reasonable treatment can be made within 5 days after the onset of the disease, which can reduce the transition to acute blood-borne osteomyelitis. The opportunity of the stage.

Differential diagnosis

1. Soft tissue inflammation Early acute osteomyelitis and early cellulitis, erysipelas and other soft tissue inflammation are often difficult to identify, soft tissue inflammation, systemic poisoning symptoms are mild, local redness is more obvious, tenderness is shallow, early acute osteomyelitis tenderness often occurs in long At the end of the diaphysis, when the single finger is examined, there are deep tenderness signs in the four planes of the affected part. This is the deep cylindrical tenderness of the limb. When the soft tissue is inflamed, the lesion is located on one side of the bone, so the tenderness is limited to one or two. Plane, this is important for early differential diagnosis, in addition, the two bone scans are not the same (Table 1).

2. Acute septic arthritis swelling and tenderness in the joint space and not at the bone end, the joint mobility is almost completely disappeared. When in doubt, the joint cavity puncture drainage test can confirm the diagnosis.

Determination of C-reactive protein content in the blood is helpful to determine whether acute hematogenous osteomyelitis is complicated by septic arthritis: when combined with septic arthritis, the C-reactive protein value is higher than that of simple osteomyelitis, and after onset This difference occurs immediately; the normal value of C-reactive protein recovery in septic arthritis patients is also late, although the erythrocyte sedimentation rate also has differential diagnosis significance, but the difference between the two groups of patients appears later, and the return to normal value is much later. It is not as good as the change of C-reactive protein to accurately reflect the clinical condition.

3. Rheumatoid arthritis is part of rheumatism, slow onset, general condition (such as fever) and local symptoms (joint swelling and pain) are mild, often multi-joint migration, erythrocyte sedimentation rate, anti-O and other blood tests Positive.

4. Malignant bone tumors, especially Ewing sarcoma, often accompanied by fever, leukocytosis, X-ray shows "onion skin-like" subperiosteal new bone formation and other phenomena, must be differentiated from osteomyelitis, the main points are: Ewing sarcoma often occurs in the backbone, The scope is wide, the systemic symptoms are not as heavy as acute osteomyelitis, but there is obvious nocturnal pain, the surface may have angulated blood vessels, and local puncture and suction biopsy can confirm the diagnosis.

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