Osteomyelitis

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Osteomyelitis_table_infobox_0

OsteomyelitisOsteomyelitis_header_cell_0_0_0
Other namesOsteomyelitis_header_cell_0_1_0 Bone infectionOsteomyelitis_cell_0_1_1
SpecialtyOsteomyelitis_header_cell_0_2_0 Infectious disease, orthopedicsOsteomyelitis_cell_0_2_1
SymptomsOsteomyelitis_header_cell_0_3_0 Pain in a specific bone, overlying redness, fever, weaknessOsteomyelitis_cell_0_3_1
ComplicationsOsteomyelitis_header_cell_0_4_0 AmputationOsteomyelitis_cell_0_4_1
Usual onsetOsteomyelitis_header_cell_0_5_0 Young or oldOsteomyelitis_cell_0_5_1
DurationOsteomyelitis_header_cell_0_6_0 Short or long termOsteomyelitis_cell_0_6_1
CausesOsteomyelitis_header_cell_0_7_0 Bacterial, fungalOsteomyelitis_cell_0_7_1
Risk factorsOsteomyelitis_header_cell_0_8_0 Diabetes, intravenous drug use, prior removal of the spleen, trauma to the areaOsteomyelitis_cell_0_8_1
Diagnostic methodOsteomyelitis_header_cell_0_9_0 Blood tests, medical imaging, bone biopsyOsteomyelitis_cell_0_9_1
Differential diagnosisOsteomyelitis_header_cell_0_10_0 Charcot's joint, rheumatoid arthritis, infectious arthritis, giant cell tumor, cellulitisOsteomyelitis_cell_0_10_1
TreatmentOsteomyelitis_header_cell_0_11_0 Antimicrobials, surgeryOsteomyelitis_cell_0_11_1
PrognosisOsteomyelitis_header_cell_0_12_0 Low risk of death with treatmentOsteomyelitis_cell_0_12_1
FrequencyOsteomyelitis_header_cell_0_13_0 2.4 per 100,000 per yearOsteomyelitis_cell_0_13_1

Osteomyelitis (OM) is an infection of bone. Osteomyelitis_sentence_0

Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. Osteomyelitis_sentence_1

The long bones of the arms and legs are most commonly involved in children, while the feet, spine, and hips are most commonly involved in adults. Osteomyelitis_sentence_2

The cause is usually a bacterial infection, but rarely can be a fungal infection. Osteomyelitis_sentence_3

It may occur by spread from the blood or from surrounding tissue. Osteomyelitis_sentence_4

Risks for developing osteomyelitis include diabetes, intravenous drug use, prior removal of the spleen, and trauma to the area. Osteomyelitis_sentence_5

Diagnosis is typically suspected based on symptoms. Osteomyelitis_sentence_6

This is then supported by blood tests, medical imaging, or bone biopsy. Osteomyelitis_sentence_7

Treatment of bacterial osteomyelitis often involves both antimicrobials and surgery. Osteomyelitis_sentence_8

In those with poor blood flow, amputation may be required. Osteomyelitis_sentence_9

Treatment of the relatively rare fungal osteomyelitis as mycetoma infections entails antifungal medications. Osteomyelitis_sentence_10

In contrast to bacterial osteomyelitis, amputation or large bony resections is a more common fate of neglected fungal osteomyelitis namely mycetoma where infections of the foot account for the majority of cases. Osteomyelitis_sentence_11

Treatment outcomes of bacterial osteomyelitis are generally good when the condition has only been present a short time. Osteomyelitis_sentence_12

About 2.4 per 100,000 people are affected a year. Osteomyelitis_sentence_13

The young and old are more commonly affected. Osteomyelitis_sentence_14

Males are more commonly affected than females. Osteomyelitis_sentence_15

The condition was described at least as early as the 300s BC by Hippocrates. Osteomyelitis_sentence_16

Before the availability of antibiotics the risk of death was significant. Osteomyelitis_sentence_17

Signs and symptoms Osteomyelitis_section_0

Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. Osteomyelitis_sentence_18

Onset may be sudden or gradual. Osteomyelitis_sentence_19

Enlarged lymph nodes may be present. Osteomyelitis_sentence_20

In fungal infections like Mycetoma there is usually a history of walking bare footed especially in rural and farming areas. Osteomyelitis_sentence_21

Contrary to the mode of infection in bacterial osteomyelitis which is mostly blood born/hematogenous, the mode of fungal osteomyelitis mycetoma originates from the skin then invades deeper tissues till it reaches the bones. Osteomyelitis_sentence_22

Cause Osteomyelitis_section_1

Osteomyelitis_table_general_1

Age groupOsteomyelitis_header_cell_1_0_0 Most common organismsOsteomyelitis_header_cell_1_0_1
Newborns (younger than 4 mo)Osteomyelitis_cell_1_1_0 S. aureus, Enterobacter species, and group A and B Streptococcus speciesOsteomyelitis_cell_1_1_1
Children (aged 4 mo to 4 y)Osteomyelitis_cell_1_2_0 S. aureus, group A Streptococcus species, Haemophilus influenzae, and Enterobacter speciesOsteomyelitis_cell_1_2_1
Children, adolescents (aged 4 y to adult)Osteomyelitis_cell_1_3_0 S. aureus (80%), group A Streptococcus species, H. influenzae, and Enterobacter speciesOsteomyelitis_cell_1_3_1
AdultOsteomyelitis_cell_1_4_0 S. aureus and occasionally Enterobacter or Streptococcus speciesOsteomyelitis_cell_1_4_1
Sickle cell anemia patientsOsteomyelitis_cell_1_5_0 Salmonella species are most common in patients with sickle cell disease.Osteomyelitis_cell_1_5_1

In children, the long bones are usually affected. Osteomyelitis_sentence_23

In adults, the vertebrae and the pelvis are most commonly affected. Osteomyelitis_sentence_24

Acute osteomyelitis almost invariably occurs in children because of rich blood supply to the growing bones. Osteomyelitis_sentence_25

When adults are affected, it may be because of compromised host resistance due to debilitation, intravenous drug abuse, infectious root-canaled teeth, or other disease or drugs (e.g., immunosuppressive therapy). Osteomyelitis_sentence_26

Osteomyelitis is a secondary complication in 1–3% of patients with pulmonary tuberculosis. Osteomyelitis_sentence_27

In this case, the bacteria, in general, spread to the bone through the circulatory system, first infecting the synovium (due to its higher oxygen concentration) before spreading to the adjacent bone. Osteomyelitis_sentence_28

In tubercular osteomyelitis, the long bones and vertebrae are the ones that tend to be affected. Osteomyelitis_sentence_29

Staphylococcus aureus is the organism most commonly isolated from all forms of osteomyelitis. Osteomyelitis_sentence_30

Bloodstream-sourced osteomyelitis is seen most frequently in children, and nearly 90% of cases are caused by Staphylococcus aureus. Osteomyelitis_sentence_31

In infants, S. aureus, Group B streptococci (most common) and Escherichia coli are commonly isolated; in children from one to 16 years of age, S. aureus, Streptococcus pyogenes, and Haemophilus influenzae are common. Osteomyelitis_sentence_32

In some subpopulations, including intravenous drug users and splenectomized patients, Gram-negative bacteria, including enteric bacteria, are significant pathogens. Osteomyelitis_sentence_33

The most common form of the disease in adults is caused by injury exposing the bone to local infection. Osteomyelitis_sentence_34

Staphylococcus aureus is the most common organism seen in osteomyelitis, seeded from areas of contiguous infection. Osteomyelitis_sentence_35

But anaerobes and Gram-negative organisms, including Pseudomonas aeruginosa, E. coli, and Serratia marcescens, are also common. Osteomyelitis_sentence_36

Mixed infections are the rule rather than the exception. Osteomyelitis_sentence_37

Systemic mycotic (fungal) infections may also cause osteomyelitis. Osteomyelitis_sentence_38

The two most common are Blastomyces dermatitidis and Coccidioides immitis. Osteomyelitis_sentence_39

In osteomyelitis involving the vertebral bodies, about half the cases are due to S. aureus, and the other half are due to tuberculosis (spread hematogenously from the lungs). Osteomyelitis_sentence_40

Tubercular osteomyelitis of the spine was so common before the initiation of effective antitubercular therapy, it acquired a special name, Pott's disease. Osteomyelitis_sentence_41

The Burkholderia cepacia complex has been implicated in vertebral osteomyelitis in intravenous drug users. Osteomyelitis_sentence_42

Pathogenesis Osteomyelitis_section_2

In general, microorganisms may infect bone through one or more of three basic methods Osteomyelitis_sentence_43

Osteomyelitis_unordered_list_0

The area usually affected when the infection is contracted through the bloodstream is the metaphysis of the bone. Osteomyelitis_sentence_44

Once the bone is infected, leukocytes enter the infected area, and, in their attempt to engulf the infectious organisms, release enzymes that lyse the bone. Osteomyelitis_sentence_45

Pus spreads into the bone's blood vessels, impairing their flow, and areas of devitalized infected bone, known as sequestra, form the basis of a chronic infection. Osteomyelitis_sentence_46

Often, the body will try to create new bone around the area of necrosis. Osteomyelitis_sentence_47

The resulting new bone is often called an involucrum. Osteomyelitis_sentence_48

On histologic examination, these areas of necrotic bone are the basis for distinguishing between acute osteomyelitis and osteomyelitis. Osteomyelitis_sentence_49

Osteomyelitis is an infective process that encompasses all of the bone () components, including the bone marrow. Osteomyelitis_sentence_50

When it is chronic, it can lead to bone sclerosis and deformity. Osteomyelitis_sentence_51

Chronic osteomyelitis may be due to the presence of intracellular bacteria (inside bone cells). Osteomyelitis_sentence_52

Also, once intracellular, the bacteria are able to escape and invade other bone cells. Osteomyelitis_sentence_53

At this point, the bacteria may be resistant to some antibiotics. Osteomyelitis_sentence_54

These combined facts may explain the chronicity and difficult eradication of this disease, resulting in significant costs and disability, potentially leading to amputation. Osteomyelitis_sentence_55

Intracellular existence of bacteria in osteomyelitis is likely an unrecognized contributing factor to its chronic form. Osteomyelitis_sentence_56

In infants, the infection can spread to a joint and cause arthritis. Osteomyelitis_sentence_57

In children, large subperiosteal abscesses can form because the periosteum is loosely attached to the surface of the bone. Osteomyelitis_sentence_58

Because of the particulars of their blood supply, the tibia, femur, humerus, vertebra, the maxilla, and the mandibular bodies are especially susceptible to osteomyelitis. Osteomyelitis_sentence_59

Abscesses of any bone, however, may be precipitated by trauma to the affected area. Osteomyelitis_sentence_60

Many infections are caused by Staphylococcus aureus, a member of the normal flora found on the skin and mucous membranes. Osteomyelitis_sentence_61

In patients with sickle cell disease, the most common causative agent is Salmonella, with a relative incidence more than twice that of S. aureus. Osteomyelitis_sentence_62

Diagnosis Osteomyelitis_section_3

The diagnosis of osteomyelitis is complex and relies on a combination of clinical suspicion and indirect laboratory markers such as a high white blood cell count and fever, although confirmation of clinical and laboratory suspicion with imaging is usually necessary. Osteomyelitis_sentence_63

Radiographs and CT are the initial method of diagnosis, but are not sensitive and only moderately specific for the diagnosis. Osteomyelitis_sentence_64

They can show the cortical destruction of advanced osteomyelitis, but can miss nascent or indolent diagnoses. Osteomyelitis_sentence_65

Confirmation is most often by MRI. Osteomyelitis_sentence_66

The presence of edema, diagnosed as increased signal on T2 sequences, is sensitive, but not specific, as edema can occur in reaction to adjacent cellulitis. Osteomyelitis_sentence_67

Confirmation of bony marrow and cortical destruction by viewing the T1 sequences significantly increases specificity. Osteomyelitis_sentence_68

The administration of intravenous gadolinium-based contrast enhances specificity further. Osteomyelitis_sentence_69

In certain situations, such as severe Charcot arthropathy, diagnosis with MRI is still difficult. Osteomyelitis_sentence_70

Similarly, it is limited in distinguishing bone infarcts from osteomyelitis in sickle cell anemia. Osteomyelitis_sentence_71

Nuclear medicine scans can be a helpful adjunct to MRI in patients who have metallic hardware that limits or prevents effective magnetic resonance. Osteomyelitis_sentence_72

Generally a triple phase technetium 99 based scan will show increased uptake on all three phases. Osteomyelitis_sentence_73

Gallium scans are 100% sensitive for osteomyelitis but not specific, and may be helpful in patients with metallic prostheses. Osteomyelitis_sentence_74

Combined WBC imaging with marrow studies have 90% accuracy in diagnosing osteomyelitis. Osteomyelitis_sentence_75

Diagnosis of osteomyelitis is often based on radiologic results showing a lytic center with a ring of sclerosis. Osteomyelitis_sentence_76

Culture of material taken from a bone biopsy is needed to identify the specific pathogen; alternative sampling methods such as needle puncture or surface swabs are easier to perform, but do not produce reliable results. Osteomyelitis_sentence_77

Factors that may commonly complicate osteomyelitis are fractures of the bone, amyloidosis, endocarditis, or sepsis. Osteomyelitis_sentence_78

Classification Osteomyelitis_section_4

The definition of OM is broad, and encompasses a wide variety of conditions. Osteomyelitis_sentence_79

Traditionally, the length of time the infection has been present and whether there is suppuration (pus formation) or sclerosis (increased density of bone) is used to arbitrarily classify OM. Osteomyelitis_sentence_80

Chronic OM is often defined as OM that has been present for more than one month. Osteomyelitis_sentence_81

In reality, there are no distinct subtypes; instead there is a spectrum of pathologic features that reflect balance between the type and severity of the cause of the inflammation, the immune system and local and systemic predisposing factors. Osteomyelitis_sentence_82

Osteomyelitis_unordered_list_1

  • Suppurative osteomyelitisOsteomyelitis_item_1_3
    • Acute suppurative osteomyelitisOsteomyelitis_item_1_4
    • Chronic suppurative osteomyelitisOsteomyelitis_item_1_5
      • Primary (no preceding phase)Osteomyelitis_item_1_6
      • Secondary (follows an acute phase)Osteomyelitis_item_1_7
  • Non-suppurative osteomyelitisOsteomyelitis_item_1_8

OM can also be typed according to the area of the skeleton in which it is present. Osteomyelitis_sentence_83

For example, osteomyelitis of the jaws is different in several respects from osteomyelitis present in a long bone. Osteomyelitis_sentence_84

Vertebral osteomyelitis is another possible presentation. Osteomyelitis_sentence_85

Treatment Osteomyelitis_section_5

Osteomyelitis often requires prolonged antibiotic therapy for weeks or months. Osteomyelitis_sentence_86

A PICC line or central venous catheter can be placed for long-term intravenous medication administration. Osteomyelitis_sentence_87

Some studies of children with acute osteomyelitis report that antibiotic by mouth may be justified due to PICC-related complications. Osteomyelitis_sentence_88

It may require surgical debridement in severe cases, or even amputation. Osteomyelitis_sentence_89

Antibiotics by mouth and by intravenous appear similar. Osteomyelitis_sentence_90

Due to insufficient evidence it is unclear what the best antibiotic treatment is for osteomyelitis in people with sickle cell disease as of 2019. Osteomyelitis_sentence_91

Initial first-line antibiotic choice is determined by the patient's history and regional differences in common infective organisms. Osteomyelitis_sentence_92

A treatment lasting 42 days is practiced in a number of facilities. Osteomyelitis_sentence_93

Local and sustained availability of drugs have proven to be more effective in achieving prophylactic and therapeutic outcomes. Osteomyelitis_sentence_94

Open surgery is needed for chronic osteomyelitis, whereby the involucrum is opened and the sequestrum is removed or sometimes saucerization can be done. Osteomyelitis_sentence_95

Hyperbaric oxygen therapy has been shown to be a useful to the treatment of osteomyelitis. Osteomyelitis_sentence_96

Before the widespread availability and use of antibiotics, blow fly larvae were sometimes deliberately introduced to the wounds to feed on the infected material, effectively scouring them clean. Osteomyelitis_sentence_97

There is tentative evidence that bioactive glass may also be useful in long bone infections. Osteomyelitis_sentence_98

Support from randomized controlled trials, however, was not available as of 2015. Osteomyelitis_sentence_99

History Osteomyelitis_section_6

The word is from Greek words ὀστέον osteon, meaning bone, μυελό- myelo- meaning marrow, and -ῖτις -itis meaning inflammation. Osteomyelitis_sentence_100

In 1875, American artist Thomas Eakins depicted a surgical procedure for osteomyelitis at Jefferson Medical College, in an oil painting titled The Gross Clinic. Osteomyelitis_sentence_101

Fossil record Osteomyelitis_section_7

Main article: Paleopathology Osteomyelitis_sentence_102

Evidence for osteomyelitis found in the fossil record is studied by paleopathologists, specialists in ancient disease and injury. Osteomyelitis_sentence_103

It has been reported in fossils of the large carnivorous dinosaur Allosaurus fragilis. Osteomyelitis_sentence_104

Osteomyelitis has been also associated with the first evidence of parasites in dinosaur bones. Osteomyelitis_sentence_105

See also Osteomyelitis_section_8

Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Osteomyelitis.