Osteomyelitis and Osteitis – Recognizing Bone Infections and Treating Bone Inflammation

Bacteria that penetrate the bone or even reach the bone marrow can cause inflammation there.

The pathogens often enter the body through open surgery or a bone fracture, triggering bone inflammation (osteitis). For osteomyelitis to develop, an additional factor must be present: in this case, the bacteria are carried by the blood (hematogenously) into the bone marrow, where they cause inflammation.

The disease usually presents in an acute form with the typical signs of inflammation:

• redness,
• pain, and
• heat.

In the chronic form, the bacteria become encapsulated within the bone. This can lead to pain and restricted movement in the joints. The condition becomes chronic in 10–30 percent of cases. Occasionally, these capsules rupture as the disease progresses and discharge their purulent contents outward.

The most common form of bone inflammation (osteitis) occurs after surgery, with men being affected more often than women. The reason for this is unknown. Children, on the other hand, are more likely to develop bone marrow inflammation (osteomyelitis).

If the disease is detected late, the inflammation can spread further within the bone marrow. This can lead to irreparable damage to the bone marrow and joints.

Illustration of osteomyelitis in the femur © designua | AdobeStock

Initially, the bacterial infection causes

• fever,
• malaise, and
• increased fatigue.

In children, the fever can rise as high as 40°C and be accompanied by chills.

Within a few days, bone and joint pain also develop. However, signs of inflammation do not become apparent until the condition progresses further. The affected areas then swell significantly and feel warm to the touch. Osteomyelitis most commonly occurs in the knee joints or upper arms.

The main cause of inflammation of the bone and bone marrow is a bacterial infection. The pathogens enter the body via

• surgical wounds,
• open fractures, or
• the bloodstream

. Depending on the route of infection, a distinction is made between:

• Hematogenous bone infections (bacteria enter the bone via the bloodstream),
• Post-traumatic osteomyelitis (bacteria enter through fractures or surgical incisions),
• Referred osteomyelitis (bacteria colonize bone tissue originating from implants).

The most common pathogens associated with osteomyelitis are:

• staphylococci,
• streptococci,
• Mycobacterium tuberculosis, among others, as well as
• very rarely, viruses and fungi.

In addition to the infection risks mentioned above, there are a number of other risk factors for infection. These include, for example:

• malnutrition,
• advanced age,
• excessive consumption of nicotine, alcohol, or drugs,
• pre-existing kidney failure,
• liver damage,
• impaired respiratory function,
• immunodeficiency,
• tumors, and
• systemic and metabolic diseases such as diabetes mellitus or atherosclerosis.

A thorough medical history provides the physician with initial clues. The physician asks the patient about their medical history and specific symptoms.

Following this, the blood is tested for inflammatory markers (e.g., C-reactive protein). The bacteria causing the inflammation can also be directly detected via a joint aspiration.

In the early stages of diagnosis, both CT and MRI can detect inflammation. These procedures are among the modern imaging techniques. If osteomyelitis has already caused bone damage, this can be easily detected on an X-ray.

To successfully treat bone marrow inflammation, the causative bacteria must be eliminated. The simplest way to do this is through antibiotic therapy.

Bacteria are becoming increasingly resistant to antibiotics worldwide. Therefore, the doctor must identify the exact strain of the pathogen before starting antibiotic therapy. Only then can it be targeted effectively. To do this, the doctor performs a puncture to collect tissue samples. These samples can then be tested in the laboratory to identify the pathogen.

Antibiotics for the treatment of osteomyelitis are taken orally (by mouth). The active ingredient dissolves and enters the bloodstream. From there, the antibiotic travels to the bone marrow via the same route as the disease-causing bacteria. The bacteria then die off, and the inflammation subsides.

The prognosis depends to a large extent

• on age,
• the type of infection,
• the type of pathogen, and
• the patient’s immune status

. As a rule, however, acute osteomyelitis is uncomplicated and therefore highly treatable.

In adults, chronic bone marrow inflammation is more common, which can complicate the prognosis.

This is particularly problematic, albeit rare, in children, whose skeletal system is still developing. Damage caused by bone or bone marrow inflammation that is detected too late can certainly lead to long-term complications. Possible consequences include skeletal deformities or leg length discrepancies.

There is no way to prevent osteomyelitis. Paying attention to your own body can help with early diagnosis. Therefore, especially after recovering from bone injuries (e.g., fractures), be on the lookout for persistent symptoms such as

• pain and
• limited mobility.

Extra caution is also needed with children. Their immune systems are not yet fully developed, making them more susceptible. This is why children are more likely to suffer from tonsillitis or other bacterial infections. In such cases, the bacteria can also spread through the bloodstream.

What is osteomyelitis?

Osteomyelitis is an infection of the bone or bone marrow caused by pathogens such as bacteria or, rarely, fungi. The disease can be acute or chronic and occurs as hematogenous osteomyelitis or exogenous osteomyelitis. Osteomyelitis and osteitis often affect bone tissue and surrounding tissue.

What are the symptoms of osteomyelitis?

Typical symptoms include pain in the affected bone, swelling, warmth, and redness. In acute osteomyelitis, fever, pus, or an abscess may also occur. Chronic osteomyelitis often causes similar symptoms over a long period of time.

How is osteomyelitis diagnosed?

Osteomyelitis is diagnosed through a physical examination, blood tests, and imaging procedures such as MRI or X-rays. When osteomyelitis is suspected, diagnostic testing and identification of the pathogens help determine the appropriate treatment. Early diagnosis of osteomyelitis is important to prevent complications or sepsis.

What is the treatment for osteomyelitis?

Treatment for osteomyelitis usually consists of antibiotic therapy and surgery to remove infected tissue. In severe cases, surgery may be necessary, particularly in cases of post-traumatic osteomyelitis or the chronic form of the disease. Treatment for osteomyelitis depends on the pathogen, the course of the disease, and the affected bone.

What are the risks and long-term consequences of osteomyelitis?

If left untreated, osteomyelitis can lead to the spread of infection, bone fractures, or chronic conditions. People with diabetes mellitus or chronic conditions such as diabetes are at an increased risk for osteomyelitis. Possible long-term consequences of osteomyelitis include permanent bone damage, limited mobility, or, in rare cases, amputation.