OSTEOMYELITIS

Disusun oleh:

Pryta Widyaningrum

030.09.186

Athika H. Romadhona

030.09.

Pembimbing :

dr.Heka P. sp.OT

RUMAH SAKIT UMUM DAERAH KOJA

Fakultas Kedokteran Universitas Trisakti

Jakarta, Desember 2013

Periode 30 September – 7 Desember 2013

Definition

Osteomyelitis is inflammation and destruction of bone and surrounding tissues, most

commonly caused by Staphylococcus Aureus, and situations, including:

An open injury to the bone, such as an open fracture with the bone ends

piercing the skin.

An infection from elsewhere in the body, such as pneumonia or a urinary tract

infection that has spread to the bone through the blood (bacteremia, sepsis).

A minor trauma, which can lead to a blood clot around the bone and then a

secondary infection from seeding of bacteria.

Bacteria in the bloodstream bacteremia (poor dentition), which is deposited in

a focal (localized) area of the bone. This bacterial site in the bone then grows,

resulting in destruction of the bone. However, new bone often forms around

the site.(1)

Osteomyelitis can be either acute or chronic. This disorder usually occurs as a result

of an infection in one part of the body that is transported through the bloodstream to a

bone in a distant location.

A chronic open wound or soft tissue infection can eventually extend down to the bone

surface, leading to a secondary bone infection.

Incidence

Osteomyelitis affects about two out of every 10,000 people. If left untreated, the

infection can become chronic and cause a loss of blood supply to the affected bone.

When this happens, it can lead to the eventual death of the bone tissue.

Osteomyelitis can affect both adults and children. The bacteria or fungus that can

cause osteomyelitis, however, differs among age groups. In adults, osteomyelitis often

affects the vertebrae and the pelvis. In children, osteomyelitis usually affects the

adjacent ends of long bones. Long bones (bones of the limbs) are large, dense bones

that provide strength, structure, and mobility. They include the femur and tibia in the

legs and the humerus and radius in the arms.

Osteomyelitis does not occur more commonly in a particular race or gender.

For example, it's estimated that between 30% and 40% of people with diabetes, who

experience a puncture injury to the foot, will develop osteomyelitis. One in every 200

people with sickle cell anaemia (a hereditary blood condition) will develop

osteomyelitis in any given year.

Risk Factor

Some people are more at risk for developing the disease, including:

People with diabetes

Patients receiving hemodialysis

People with weakened immune systems

People with sickle cell disease

Intravenous drug abusers

The elderly

Etiology

Osteomyelitis is caused by

Contiguous spread (from infected tissue or an infected prosthetic joint)

Bloodborne organisms (hematogenous osteomyelitis)

Open wounds (from contaminated open fractures or bone surgery)

Trauma, ischemia, and foreign bodies predispose to osteomyelitis. Osteomyelitis may

form under deep decubitus ulcers.

About 80% of osteomyelitis results from contiguous spread or from open wounds; it

is often polymicrobial. Staphylococcus aureus (including both methicillin-sensitive

and methicillin-resistant strains) is present in ≥ 50%; other common bacteria include

streptococci, gram-negative enteric organisms, and anaerobic bacteria. Osteomyelitis

that results from contiguous spread is common in the feet (in patients with diabetes or

peripheral vascular disease), at sites of bone penetrated by trauma or surgery, sites

damaged by radiation therapy, and in bones contiguous to decubitus ulcers, such as

the hips and sacrum. A sinus, gum, or tooth infection may spread to the skull.

Hematogenously spread osteomyelitis usually results from a single organism. In

children, gram-positive bacteria are most common, usually affecting the metaphyses

of the tibia, femur, or humerus. Hematogenously spread osteomyelitis in adults

usually affects the vertebrae. Risk factors in adults are older age, debilitation,

hemodialysis, sickle cell disease, and IV drug use. Common infecting organisms

include S. aureus (methicillin-resistant S. aureus [MRSA] is common) and enteric

gram-negative bacteria (in adults who are older, debilitated, or receiving

hemodialysis); S. aureus, Pseudomonas aeruginosa, and Serratia sp (in IV drug

users); and Salmonella sp (in patients with sickle cell disease). Fungi and

mycobacteria can cause hematogenous osteomyelitis, usually in immunocompromised

patients or in areas of endemic infection with histoplasmosis, blastomycosis, or

coccidioidomycosis. The vertebrae are often involved.

Pathophysiology

The pathogenesis of osteomyelitis has been explored in various animal

models; these studies have found that normal bone is highly resistant to infection,

which can only occur as a result of very large inocula, trauma, or the presence of

foreign bodies. Certain major causes of infection, such as Staphylococcus aureus,

adhere to bone by expressing receptors (adhesins) for components of bone matrix

(fibronectin, laminin, collagen, and bone sialoglycoprotein); the expression of the

collagen-binding adhesin permits the attachment of the pathogen to cartilage. The role

of the fibronectin-binding adhesins of S. aureus in the attachment of bacteria to

devices surgically implanted in bone has recently been elucidated.

Fibronectin-Binding Protein and the Degree of Adherence of S. aureus to

Bone-Implanted Metallic Devices. S. aureus that has been internalized by cultured

osteoblasts can survive intracellularly. The intracellular survival of bacteria

(sometimes in a metabolically altered state, in which they appear as so-called small-

colony variants) may explain the persistence of bone infections. Once the

microorganisms adhere to bone, they express phenotypic resistance to antimicrobial

treatment, which may also explain the high failure rate of short courses of therapy.

Normal bone remodeling requires the coordinated interplay of osteoblasts and

osteoclasts. Cytokines (such as interleukin-1, interleukin-6, interleukin-11, and tumor

necrosis factor) generated locally by inflammatory and bone cells are potent osteolytic

factors. The role of bone growth factors in normal bone remodeling and their

therapeutic usefulness are still unclear. During infection, phagocytes attempt to

contain invading microorganisms and, in the process, generate toxic oxygen radicals

and release proteolytic enzymes that lyse surrounding tissues. Several bacterial

components act directly or indirectly as bone-modulating factors. The presence of

arachidonic acid metabolites, such as prostaglandin E2, which is a strong osteoclast

agonist generated in response to fracture, decreases the amount of the bacterial

inoculum needed to produce infection.

Pus spreads into vascular channels, raising the intraosseous pressure and impairing

blood flow. The ischemic necrosis of bone results in the separation of devascularized

fragments, which are called sequestra. Microorganisms, infiltrations of neutrophils,

and congested or thrombosed blood vessels are therefore the principal histologic

findings in acute osteomyelitis. One of the distinguishing features of chronic

osteomyelitis is necrotic bone, which can be recognized by the absence of living

osteocytes.(2)

PATHOPHYSIOLOGY OF OSTEOMYELITIS

SEKELETAL

SYSTEM

Risk Factors:

-trauma

-diabetes

-hemodialysis

-splenectomy

ETIOLOGY/CAUSE:

- Newborns (younger than 4 mo)

S. aureus, Enterobacter species, and group A and B Streptococcus species

- Children, adolescents (aged 4 y to adult) S. aureus (80%), group A Streptococcus species, H. influenzae, and Enterobacter species

- Adult S. aureus and occasionally Enterobacter or

Bacterial invasion ( hematogenous, loval extension , trauma)

Neutrophil invasion

Compensatory Mechanisms

Gross/Anatomical Physical Changes:

Vascular congestionSmall vessel thrombosisEdemainflammation

if compensation failsgreat losses

Molecular Changes:

Pus spread to vascular channelIncrease intraosseous pressureDecreased blood flowexudation of polymorphonuclear leukocytesincreased erythrocytesincreased WBC

Hematogenous Osteomyelitis

Osteomyelitis develops after bacteremia mostly in prepubertal children and in

elderly patients. In children, infection is usually located in the metaphyseal area of

long bones (particularly the tibia and femur), usually as a single focus

Pathophysiologic Manifestation on Effect on Bodily Function:

↓ cardiac output↓ impaired cellular metabolismischemic necrosissystemic infectionlysis of the bone cell

Clinical Manifestations ( S/S ) :

Increased CRP compliment reactive proteinIncreased erythrocyte sendimentatiion rate ESR

Drainage of pus through the skin

Pain and/or tenderness in the

infected area

Swelling and warmth in the

infected area

Fever

Nausea, secondarily from being ill

with infection

Laboratory Exams:

CBCBone scanESRBone lesion biopsy or culture

Bone sclerosis or deformity

Complications:

Multiple Organ FailureDeath

Appearance on MRI of Various Types of Osteomyelitis.

The clinical features of this form of osteomyelitis are typically chills, fever and

malaise, local pain, and swelling. Blood cultures are often positive for the infection.

Total-body scintigraphy is useful in detecting any metastatic sites of infection and

should be repeated in case of an early negative result.

The infecting organisms differ according to the age of the patient. S. aureus and

streptococci are typical in neonates; S. aureus is found later in life; and gram-negative

rods are found in the elderly. Fungal osteomyelitis is a complication of catheter-

related fungemia, the use of illicit drugs contaminated by candida species, and

prolonged neutropenia. Pseudomonas aeruginosa can be isolated from injection-drug

addicts (often from cervical vertebrae) and from patients with urinary catheters in

place for long periods (often from lumbar vertebrae).

Vertebral infection, a rare disease in adults, typically involves two adjacent vertebrae

and the disk space between them. Neck or back pain and fever are the main

symptoms. Blood cultures are often negative, so needle biopsy with multiple

specimens for microbiologic and pathological examination is the diagnostic procedure

of choice. If the culture from the first biopsy specimen is negative, a second biopsy

guided by CT should be performed. In the event of a second failure to establish the

diagnosis, the alternatives are either empirical therapy or an open surgical biopsy.(2)

Osteomyelitis Due to a Contiguous Focus of Infection

Osteomyelitis after injury is the most prevalent type and is usually associated

with an open fracture or occurs after surgery necessary for reconstruction of bone.

Infections associated with prostheses are also common. Between 500,000 and 1

million hip replacements per year were performed worldwide during the late 1980s;

because the techniques for other joint replacements (e.g., knee or elbow) have

improved, the annual number of artificial joints inserted has become much higher.

Infection associated with a prosthesis may occur within 12 weeks after surgery (acute

infection), within 24 months after surgery (chronic infection, often with less virulent

microorganisms), and in patients with hematogenous infection, even later. Patients

usually have little or no fever and present with a painful, unstable joint on physical

examination or radiography. Because of the difficulty of distinguishing mechanical

from infectious loosening, a positive culture of fluid aspirated from the artificial-joint

space or of bone from the bone–cement interface is required for diagnosis. Gram's

staining and quantitative cultures of material obtained from deep tissues are useful in

distinguishing colonization from infection. Coagulase-positive and coagulase-

negative staphylococci account for 75 percent of the bacteria cultured.

Osteomyelitis Due to Vascular Insufficiency

In patients with diabetes or vascular insufficiency, osteomyelitis is found almost

exclusively in the feet. The disease starts insidiously in an area of previously

traumatized skin in a patient with claudication. Cellulitis may be minimal as the

infection progressively burrows its way to the underlying bone (e.g., toes, metatarsal

heads, and tarsal bones). Physical examination elicits either no pain (if there is

advanced neuropathy) or excruciating pain (if the destruction of bone has been acute).

One must carefully assess the vascular supply to the affected limb and look for

concomitant neuropathy. If one can gently advance a sterile surgical probe to reach

bone, the diagnosis of osteomyelitis is clearly established. In cases of early bone

infection in which the clinical presentation does not establish the diagnosis and the

results of plain-film radiographs are still normal, MRI may permit the detection of the

early infection. The extent of vascular compromise can be assessed by transcutaneous

oximetery (once inflammation has been controlled) and by measurements of pulse

pressure with Doppler ultrasonography. If serious ischemia is suspected,

arteriography, including examination of the foot vessels, should be performed.(2)

Diagnosing osteomyelitis

To diagnose osteomyelitis, the doctor will first perform a history, review of systems,

and a complete physical examination. In doing so, the physician will look for signs or

symptoms of soft tissue and bone tenderness and possibly swelling and redness. The

doctor will also ask you to describe your symptoms and will evaluate your personal

and family medical history. The doctor can then order any of the following tests to

assist in confirming the diagnosis:

Blood tests: When testing the blood, measurements are taken to confirm an

infection: a CBC (complete blood count), which will show if there is an

increased white blood cell count; an ESR (erythrocyte sedimentation rate);

and/or CRP (C-reactive protein) in the bloodstream, which detects and

measures inflammation in the body.

Blood culture: A blood culture is a test used to detect bacteria. A sample of

blood is taken and then placed into an environment that will support the

growth of bacteria. By allowing the bacteria to grow, the infectious agent can

then be identified and tested against different antibiotics in hopes of finding

the most effective treatment.

Needle aspiration: During this test, a needle is used to remove a sample of

fluid and cells from the vertebral space, or bony area. It is then sent to the lab

to be evaluated by allowing the infectious agent to grow on media.

Biopsy: A biopsy (tissue sample) of the infected bone may be taken and tested

for signs of an invading organism.

Bone scan: During this test, a small amount of Technetium-99 pyrophosphate,

a radioactive material, is injected intravenously into the body. If the bone

tissue is healthy, the material will spread in a uniform fashion. However, a

tumor or infection in the bone will absorb the material and show an increased

concentration of the radioactive material, which can be seen with a special

camera that produces the images on a computer screen. The scan can help your

doctor detect these abnormalities in their early stages, when X-ray findings

may only show normal findings.

Cierny and Mader classified osteomyelitis based on the affected portion of the bone, the physiologic status of the host and the local environment. This classification lends itself to the treatment and prognosis of osteomyelitis; stage 1 (medullary osteomyelitis) can usually be treated with antibiotics alone, while stages 2, 3 and 4 (superficial, localized and diffuse osteomyelitis) usually require aggressive debridement, antimicrobial therapy and subsequent orthopedic reconstruction. 

Cierny-Mader staging system for long bone osteomyelitis

Anatomic type

Stage 1: Medullary osteomyelitis

Medullary osteomyelitis denotes infection confined to the intramedullary surfaces of the bone. Hematogenous osteomyelitis and infected intramedullary rods are examples of this anatomic type.

Stage 2: Superficial osteomyelitis

Superficial osteomyelitis is a true contiguous focus infection of bone; it occurs when an exposed infected necrotic surface of bone lies at the base of a soft-tissue wound.

Stage 3: Localized osteomyelitis

Localized osteomyelitis is usually characterized by a full thickness, cortical sequestration which can be removed surgically without compromising bony stability.

Stage 4: Diffuse osteomyelitis

Diffuse osteomyelitis is a through-and-through process that usually requires an intercalary resection of the bone to arrest the disease process. Diffuse osteomyelitis includes those infections with a loss of bony stability either before or after debridement surgery.

 

Physiologic class of hostClass A denotes a normal hostClass B denotes a host with systemic compromise, local compromise, or bothClass C denotes a host for whom the morbidity of treatment is worse than that imposed by the disease itself

Factors affecting immune surveillance, metabolism, and local vascularity

Systemic factors

Malnutrition Renal or hepatic failure

Diabetes mellitus

Chronic hypoxia

Immune disease

Malignancy

Extremes of age

Immunosuppression or immune deficiency

 

Local factors

Chronic lymphedema Venous stasis

Major vessel compromise

Arteritis

Small vessel disease

Extensive scarring

Radiation fibrosis

Neuropathy

Tobacco abuse (>/= 2 packs per day)

ANTIBIOTIC PROPHYLAXIS IN BONE SURGERY

In patients undergoing bone surgery, antibiotics should be administered

intravenously 30 minutes before incision of the skin and for no longer than 24 hours

after the operation. In orthopedic surgery for closed fractures, antistaphylococcal

penicillins and first-, second-, or third-generation cephalosporins decrease the

incidence of postoperative infection. By definition, open fractures include those in a

large proportion of patients who have contaminated or infected wounds at the time of

surgery.

In patients who can receive antibiotics within six hours after injury and who

receive prompt operative treatment, administration of first-generation (cefazolin) or

second-generation (cefamandole and cefuroxime) cephalosporins for one day is

appropriate. The drug therapy should be followed by close observation and treatment

with appropriate antibiotics and surgery if a postoperative infection is diagnosed.

However, the treatment of complex fractures with extensive soft-tissue damage

requires broader antibiotic therapy for longer periods.

With respect to the insertion of prosthetic devices, several experimental studies and

the early clinical experience have shown high susceptibility to infection when only a

few microorganisms of low pathogenicity, such as S. epidermidis or

propionibacterium species, are present.41 In such procedures, good preoperative

preparation, the use of surgical rooms with laminar air flow, and prophylactic

antibiotic treatment have decreased the rate of infection to around 0.5 to 2 percent.(2)

Treating and managing osteomyelitis

The objective of treating osteomyelitis is to eliminate the infection and prevent the

development of chronic infection. Chronic osteomyelitis can lead to permanent

deformity, possible fracture, and chronic problems, so it is important to treat the

disease as soon as possible.

Drainage: If there is an open wound or abscess, it may be drained through a

procedure called needle aspiration. In this procedure, a needle is inserted into the

infected area and the fluid is withdrawn. For culturing to identify the bacteria, deep

aspiration is preferred over often-unreliable surface swabs. Most pockets of infected

fluid collections (pus pocket or abscess) are drained by open surgical procedures.

Medications: Prescribing antibiotics is the first step in treating osteomyelitis.

Antibiotics help the body get rid of bacteria in the bloodstream that may otherwise re-

infect the bone. The dosage and type of antibiotic prescribed depends on the type of

bacteria present and the extent of infection. While antibiotics are often given

intravenously, some are also very effective when given in an oral dosage. It is

important to first identify the offending organism through blood cultures, aspiration,

and biopsy so that the organism is not masked by an initial inappropriate dose of

antibiotics. The preference is to first make attempts to do procedures (aspiration or

bone biopsy) to identify the organisms prior to starting antibiotics.

Splinting or cast immobilization: This may be necessary to immobilize the affected

bone and nearby joints in order to avoid further trauma and to help the area heal

adequately and as quickly as possible. Splinting and cast immobilization are

frequently done in children, although motion of joints after initial control is important

to prevent stiffness and atrophy.

Surgery: Most well-established bone infections are managed through open surgical

procedures during which the destroyed bone is scraped out. In the case of spinal

abscesses, surgery is not performed unless there is compression of the spinal cord or

nerve roots. Instead, patients with spinal osteomyelitis are given intravenous

antibiotics. After surgery, antibiotics against the specific bacteria involved in the

infection are then intensively administered during the hospital stay and for many

weeks afterward.

With proper treatment, the outcome is usually good for osteomyelitis, although results

tend to be worse for chronic osteomyelitis, even with surgery. Some cases of chronic

osteomyelitis can be so resistant to treatment that amputation may be required;

however, this is rare. Also, over many years, chronic infectious draining sites can

evolve into a squamous-cell type of skin cancer; this, too, is rare. Any change in the

nature of the chronic drainage, or change of the nature of the chronic drainage site,

should be evaluated by a physician experienced in treating chronic bone infections.

Because it is important that osteomyelitis receives prompt medical attention, people

who are at a higher risk of developing osteomyelitis should call their doctors as soon

as possible

Symptoms of osteomyelitis

The symptoms of osteomyelitis can include:

Pain and/or tenderness in the infected area

Swelling and warmth in the infected area

Fever

Nausea, secondarily from being ill with infection

General discomfort, uneasiness, or ill feeling

Drainage of pus through the skin

Additional symptoms that may be associated with this disease include:

Excessive sweating

Chills

Lower back pain (if the spine is involved)

Swelling of the ankles, feet, and legs

Changes in gait (walking pattern that is a painful, yielding a limp)

Chronic osteomyelitis causes intermittent (months to many years) bone pain,

tenderness, and draining sinuses.

Types

There are three main types of osteomyelitis:

Acute osteomyelitis, where the bone infection develops within two

weeks of an initial infection, injury or the onset of an underlying

disease.

Sub-acute osteomyelitis, where the bone infection develops

within one ot two months of an initial infection, injury or onset

of an underlying disease.

Chronic osteomyelitis, where the bone infection develops two months

or more after an initial infection, injury or onset of an underlying

disease.

Stages of Osteomyelitis

Prognosis

With early diagnosis and appropriate treatment, the prognosis for

osteomyelitis is good. Antibiotics regimes are used for four to eight weeks and

sometimes longer in the treatment of osteomyelitis depending on the bacteria that

caused it and the response of the patient. Commonly, patients can make a full

recovery without longstanding complications.

However, if there is a long delay in diagnosis or treatment, there can be severe

damage to the bone or surrounding soft tissues that can lead to permanent deficits or

make the patient more prone to reoccurrence. If surgery or bone grafting is needed,

this will prolong the time it takes to recover.(3)

Daftar Pustaka

1. Osteomyelitis. Medlineplus. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000437.htm

2. Osteomyelitis. The New England Journal of medicine. Available at: http://www.nejm.org/doi/full/10.1056/NEJM199704033361406.

3. Osteomyelitis. MediciNet.com. Available at: http://www.medicinenet.com/osteomyelitis/page3.htm#what_is_the_treatment_for_osteomyelitis