Osteomyelitis is an inflammatory disease of the bone marrow that can in principle affect all bones in the body. The cause of bone marrow inflammation is often bacteria, especially staphylococci. Learn more about the symptoms, diagnosis and treatment options!
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Quick Overview: Osteomyelitis
Causes: In most cases, bone marrow inflammation is caused by bacteria. They can enter the bone marrow from outside through inflammation that is already present in the body (such as tonsillitis) or through injuries or operations.
Symptoms: An acute infection may cause fever and chills. Swelling, overheating and pressure pain in the affected area are also typical.
Diagnosis: Diagnosis is made through blood tests and imaging procedures such as ultrasound, X-rays, MRI or scintigraphy.
Therapy: Acute osteomyelitis is usually treated in hospital with antibiotics. In severe cases, surgery may be necessary.
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What is osteomyelitis?
In osteomyelitis, the inside of the bone, the bone marrow, is inflamed. If, on the other hand, the outer part of the bone becomes diseased, experts speak of osteitis (inflammation of the bone). However, since the bone marrow as well as the joints and the periosteum are usually affected, the terms are often used synonymously.
The cause of bone marrow inflammation is usually an infection with bacteria, most commonly staphylococci. Viruses or fungi are less common pathogens.
Osteomyelitis can occur in any bone. Infections often occur in the long bones of the arms and legs, but hand or jaw bones can also be affected.
Bone marrow inflammation: who is affected?
Acute osteomyelitis occurs primarily in children under 5 years of age. Older people over 60, on the other hand, are often affected by the chronic form – men more often than women. In addition, people with diabetes mellitus have an increased risk of developing a bone infection. Patients with joint prostheses are also more susceptible: around one to two percent develop inflammation in the bone marrow.
Symptoms: This is how osteomyelitis manifests itself
The symptoms of osteomyelitis can be very different. They depend, among other things, on whether bacteria are the cause of the bone marrow inflammation and whether it is acute or chronic.
Bacterial osteomyelitis
Acute osteomyelitis is usually accompanied by severe, very general symptoms. Examples are:
With chronic bone inflammation, the symptoms are less severe. However, acute attacks can always occur.
Non-bacterial bone marrow inflammation
Such general symptoms are absent in osteomyelitis, which is caused by other pathogens. The most important symptom is pain in several areas of the body. In addition, localized swelling and overheating can occur.
In the rheumatic form of bone marrow inflammation, skin changes such as psoriasis or acne can also occur.
Causes of osteomyelitis
In principle, bacteria can get into the bone in two ways: either they enter from the outside, for example through a wound or during an operation, and directly infect the bone marrow. Or they reach the bones and bone marrow from an existing source of infection in the body via the bloodstream.
The bacteria is present in around 80 percent of all cases of osteomyelitis Staphylococcus aureus responsible.
Less common causes of osteomyelitis are:
- Streptococci
- Haemophilus influenzae
- Pseudomonas aeruginosa
- Salmonella
- Mycobacterium tuberculosis
- Escherichia coli
- viruses or fungi
Certain factors such as diabetes mellitus or a weakened immune system increase the risk of bone marrow inflammation.
Osteomyelitis: What forms are there?
Experts differentiate between different forms of osteomyelitis, depending on whether the inflammation arises from hematogenous spread (endogenous) or is due to exogenous causes (injuries, operations). In addition, the disease can be acute or chronic.
Acute hematogenous osteomyelitis: Bacteria enter the bone marrow from another source of infection in the body and infect it. This can be the case, for example, with tonsillitis or a urinary tract infection. The pathogens are already present in the body. The form primarily affects children and adolescents, whose bones have a very good blood supply. The thigh bone (femur) and the shin bone (tibia) in particular are often affected.
Acute exogenous osteomyelitis: The Purulent inflammation of the bone marrow occurs after an open fracture (fracture) or surgery on the bone. The pathogen is introduced from outside (exogenously) and does not reach the bone via the bloodstream.
Primary chronic osteomyelitis: The body’s own immune system was able to keep the pathogens in check, but was not able to successfully eliminate them. As a result, an abscess develops in the bone (Brodie abscess) or the bone cortex hardens (sclerosation). The bacteria that cause it are usually not detectable.
Secondary-chronic osteomyelitis: In this form, the pathogens were introduced into the joint or bone from outside and settled there. This causes inflammatory attacks and purulent fistulas.
Other forms of osteomyelitis
There are rheumatic forms of osteomyelitis that are not caused by bacterial infection. An important special form is chronic recurrent (recurring or recurrent) multifocal osteomyelitis (CRMO), which primarily occurs in children and adolescents and is often associated with an autoimmune disease.
A particular emergency is osteomyelitis in infants, which is caused, for example, by an umbilical cord infection or pneumonia. It requires immediate surgical treatment, otherwise it can destroy bones near the joint and cause growth problems.
This is how the diagnosis of osteomyelitis is made
To diagnose osteomyelitis, a physical examination is first carried out and the medical history (anamnesis) is taken in order to obtain evidence of an existing source of infection.
Doctors ask, for example, whether they are aware of tonsillitis, sinusitis, tooth root inflammation or inflammation of an sebaceous gland. This can provide initial indications as to whether endogenous osteomyelitis may be present. If those affected have recently had a joint operation or injury, this is more likely to indicate exogenous osteomyelitis.
A blood test shows whether certain inflammation levels are increased. The pathogen can also be isolated and identified, which is important for choosing the right antibiotic. This can also be achieved through a joint puncture, in which synovial fluid is removed using a thin needle.
Imaging procedures
Imaging procedures are also used to determine the location and extent of the bone marrow inflammation more precisely. This includes:
Ultrasound examination: Evidence of abscess (purulent inflammation) or joint effusion
scintigraphy: especially in acute hematogenous osteomyelitis
Magnetic resonance imaging (MRI = magnetic resonance imaging): An MRI primarily helps to differentiate bone marrow inflammation from Ewing’s sarcoma, a very malignant form of bone cancer.
X-ray image: in the late stage, when bony changes are already present
Blood count: Important blood values and what they mean
Therapy of osteomyelitis
The aim of therapy is to stop the infection and prevent complications such as life-threatening blood poisoning (sepsis).
In the case of acute bone marrow inflammation, the affected extremity (arm, leg) is elevated and immobilized, for example with a splint. The patients also receive high-dose antibiotic therapy for around four to six weeks. Children are usually treated with penicillins. Therapy usually takes place in the hospital.
Surgical treatment for bone marrow inflammation
If the symptoms do not improve with antibiotics, doctors try to remove the bacteria surgically. For example, abscesses or dead tissue (necrosis) are eliminated. These form the breeding ground for the infection to continue and possibly spread.
In chronic osteomyelitis, an insert containing antibiotics is sometimes inserted into the purulent focus of infection to completely kill the bacteria. If the germs have severely damaged the bone substance, it must be filled up to ensure the stability of the bone. In this so-called spongiosaplasty, surgeons transfer healthy bone tissue into the diseased bone section.
After the operation, those affected continue to receive antibiotics and the affected area of the body is immobilized. In the first year, patients have to go for check-ups every three months. This is the only way to ensure that the osteomyelitis has healed completely. An annual check is sufficient for the following two years.
Course and prognosis of osteomyelitis
If left untreated, osteomyelitis can lead to life-threatening blood poisoning if the pathogens spread through the bloodstream. Children up to the age of two are also at risk of bacteria infecting their joints. The consequences can be purulent joint effusions, joint damage and growth disorders. The affected limb shortens or deforms, which may require subsequent orthopedic surgery. Adults are more prone to chronic osteomyelitis, which is accompanied by bone changes and increases the risk of bone fractures.
It is crucial that acute bone marrow inflammation is diagnosed and treated in a timely manner. Then it often heals without any lasting damage. Complete recovery usually occurs, especially in children and adolescents. In some cases, repeated relapses are possible.
Can osteomyelitis be prevented?
Osteomyelitis cannot be specifically prevented. However, existing infections should always be treated as quickly as possible to reduce the risk of osteomyelitis. It is recommended that any swelling or warming of the joints should always be checked by a doctor.
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