What Is Osteomyelitis?

Osteomyelitis is an infection and destruction of bones that can be caused by aerobic or anaerobic bacteria, mycobacteria, and fungi. Osteomyelitis is prevalent in long bones, in the feet of diabetic patients, or in areas of penetrating bone injury caused by trauma or surgery. The most common site in children is long bones with good blood supply, such as the metaphysis of the tibia or femur.

Basic Information

English name: osteomyelitis
Visiting department: orthopedics
Common locations: Long bone

Common causes: Caused by a blood-borne infection or by trauma or surgical infection
Common symptoms: Bone pain, difficulty walking, local swelling, etc.
Contagious: no

Causes of osteomyelitis

Infections are caused by blood-borne microorganisms (blood-induced osteomyelitis); they spread from infected tissues, including infections that replace joints, contaminated fractures, and bone surgery. The most common pathogen is Gram-positive bacteria. Osteomyelitis caused by gram-negative bacteria can be seen in drug users, patients with sickle cell disease, and patients with severe diabetes or trauma. Fungal and mycobacterial infections are often confined to bone and cause painless chronic infections. Risk factors include wasting disease, radiation therapy, malignancy, diabetes, hemodialysis, and intravenous medication. In children, any process that causes bacteremia can induce osteomyelitis.

Clinical manifestations of osteomyelitis

Osteomyelitis refers to inflammatory diseases caused by pyogenic bacteria infection of bone marrow, bone cortex and periosteum. Most of them are caused by blood, but also caused by trauma or surgical infection. Most of them are caused by pyogenic bacillus or other lesions in the blood. And reach the bone tissue. Limbs and bones are most susceptible to invasion, especially the hip joint. Recurrent episodes are common clinically, which seriously affects physical and mental health and work ability. Acute osteomyelitis has high fever and local pain at the onset of osteomyelitis. When it is turned into chronic osteomyelitis, it will have ulcers, pus, and dead bones or hollows. Severe patients are often life-threatening and sometimes have to take emergency measures for amputation, which can lead to life-long disability.

Osteomyelitis

Laboratory inspection

The white blood cell count can be normal. But ESR and C-reactive protein increased.

2.X-ray inspection

X-ray changes appear 3 to 4 weeks after infection, showing irregular thickening and sclerosis of bone, residual bone resorption areas or voids, which may include dead bones of various sizes, and sometimes the bone marrow cavity is not visible. Some small bone cavities and small dead bones cannot be visualized in hardened bones, so the actual number is often more than shown in the photos.

3.CT inspection

If the X-ray findings are not clear, CT examination can be used to determine the formation of the diseased bone and show the formation of paravertebral abscess. The radiation bone scan is reflected in the early stage of the disease, but it cannot distinguish the infection.

4. Biopsy

For fractures and tumors, a biopsy and surgical biopsy can be performed through the disc space or infected bone. Feasible bacterial culture and drug sensitivity test.

5. Iodine oil contrast

In order to clarify the relationship between dead bone or bone cavity and sinus tract, iodized oil or 12.5% sodium iodide solution can be used for sinus angiography.

Osteomyelitis diagnosis

Patients with this disease often experience localized bone pain, fever, and discomfort, suggesting that osteomyelitis may be present. The white blood cell count is normal. But ESR and C-reactive protein increased. X-ray examination changes occurred 3 to 4 weeks after infection. Bone destruction, swelling of the soft tissue, and invasion of the subchondral bone plate can be seen. The intervertebral disc space is narrowed and bone destruction is accompanied by shortened vertebrae. If the X-ray findings are not clear, CT examination can be used to determine the formation of diseased bone and show the formation of paravertebral abscess. The radiation bone scan is reflected in the early stage of the disease, but it cannot distinguish the infection, fracture and tumor, and the puncture biopsy can be performed through the disc space or infected bone. And surgical biopsy.

Differential diagnosis of osteomyelitis

Clinically, the type of osteomyelitis and diseases with similar clinical manifestations as osteomyelitis need to be identified:

1. For bloodborne osteomyelitis, there are three main types of clinical

(1) Acute hematogenous osteomyelitis is characterized by systemic symptoms, no change in X-ray examination within 10 days of onset, and most cases have no history of previous attacks.

(2) Subacute hematogenous osteomyelitis is characterized by no symptoms of systemic poisoning, X-ray changes have occurred at the time of onset, the course of the disease has been more than 10 days, and there is no history of previous attacks.

(3) Chronic blood-borne osteomyelitis is characterized by the presence or absence of systemic symptoms based on changes in the condition, X-ray changes are common, and a history of previous infection episodes.

2. Diseases to be identified for acute osteomyelitis

From the whole body, it should be distinguished from acute rheumatic fever and acute leukemia. From the local and X-rays, it should be distinguished from osteosarcoma, Ewing sarcoma, and osteocytosis:

(1) Osteosarcoma usually occurs in the age of 10 to 20 years. Most of the bones in the limbs occur in the epiphysis of long bones. Occasionally, they occur in the bones. Compared with osteomyelitis, the scope of bone destruction and periosteal reaction is more limited. But sometimes X-ray identification is difficult; identification by CT, MRI, and biopsy is necessary.

(2) Ewing sarcoma is often difficult to distinguish from osteomyelitis. Ewing's sarcoma occurs in the backbone of the limbs; sometimes with severe pain, accompanied by fever and localized heat; increased erythrocyte sedimentation; increased white blood cells; CRP positive, showing an inflammatory response. On the X-ray, the periosteal response is the main part in the early stage, and the lack of changes in the bone marrow makes diagnosis difficult. Compared with osteomyelitis, the periosteal reaction is regular and mostly onion-like periosteal reaction, which is characteristic. A biopsy must confirm the diagnosis.

(3) Osteocytosis According to the site of the disease, various X-ray images are displayed. Occurs when the long tubular bones of the extremities have a high degree of osteogenesis and a significant periosteal reaction. Due to mild inflammation symptoms locally and throughout the body, compared with osteomyelitis, the extent of osteoclastosis and periosteal reaction They are all limited; as seen from dead bones, sometimes no sclerosis appears.

(4) Osteoid osteoma is sometimes difficult to distinguish from osteomyelitis. On the X-ray, it often occurs in the bias of the long tubular bone (that is, it occurs in the upper or lower center). The X-ray shows a high periosteal response and cortical hypertrophy. If you observe carefully, you can see the osseous radiograph of the lesion.

Osteomyelitis complications

There are several possible complications of chronic osteomyelitis:

Deformity

As the epiphysis is stimulated by inflammation, the affected limb becomes excessively long and grows longer, or the epiphyseal plate is damaged, which affects development. As a result, the limb is shortened, the epiphyseal plate is damaged on one side, the development is asymmetric, and the joint is varus or valgus deformity. ; Due to soft tissue scar contracture, flexion deformity can also be caused.

2. Joint rigidity

As the infection spreads into the joint, the articular cartilage surface is destroyed, making the joint fibrous or bony.

3. Cancerous

The sinus ostium skin can be associated with cancer due to constant irritation, and squamous cell carcinoma is common.

Osteomyelitis treatment

Thorough removal of the lesion, open cancellous bone grafting and repeated irrigation are currently the most commonly used treatments.

Puncture suction

In order to reduce the pressure in the bone marrow cavity and prevent inflammation from spreading up and down the bone marrow cavity, puncture and suction can be performed on the lesion and antibiotics can be injected into the cavity.

2.window drainage

X-ray examination shows that the bone has been locally damaged and the shadow of the bone marrow cavity has widened. Cortical drilling or opening of the bone can be performed in the pus in the bone marrow cavity to prevent the spread of inflammation and facilitate drainage of secretions. Or perform closed lavage treatment with antibiotics up and down the wound cavity.

3. Dead bone removal

It is the most common and basic surgical method for the treatment of chronic osteitis if the dead bone is large and the surgical time is available.

4. Pedicled muscle flap filling

Due to the large bone cavity, the bone cavity is eliminated, the sinus is not cured for a long time, and the cancellous bone filling and defect of the normal muscle tissue are filled.

5. Amputation

It is suitable for those who have multiple osteomyelitis in one limb, combined with most sinuses, who can't heal for a long time, or who have long-term stimulation of local skin due to chronic inflammation.

6. Mass diseased bone resection

It is generally applicable to patients with chronic osteomyelitis with chronic blood-derived osteomyelitis. The diseased bone has hardened significantly, or there are many local scars.

Osteomyelitis prevention

1. Scab, scabies, sores, scabies, and upper respiratory tract infections are the most common infectious diseases, and the most prone to secondary infections and the occurrence of blood-induced osteomyelitis. Therefore, the prevention of scabies, sores, scabies, and upper respiratory infections is very important to prevent the occurrence of osteomyelitis.

2. Traumatic infections include infections after tissue damage and infections after skeletal damage, which are also common causes of osteomyelitis. Therefore, active prevention should be paid attention to in daily life.

3. For infectious diseases, they should be detected early and treated promptly.

4. Open fractures must first prevent infection. Open fractures that have been internally fixed. Once infection occurs and spreads to the medullary cavity, inflammatory infections often spread to both ends along the intramedullary needle, and infection may also form under the skin where the intramedullary needle penetrates or exits. Special attention should be paid to removing the internal fixation to control infection.