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Osteomyelitis

 

BP takes a look at Osteomyelitis, a very serious bone
infection which has recently been resurfacing in the
IV drug using community & with worrying results... Hard to detect and diagnose, it's more important than ever that we know something of it's signs and symptoms.

Infection inside the bone

After noticing a considerable increase in the numbers of IV drug users who have been diagnosed with osteomyelitis. BP thought some investigation was needed as it appears to be an infection most of us know very little about, but which can have some extremely serious consequences if left untreated. Osteomyelitis is a serious bone infection which can occur in virtually any bone in the body although it usually crops up in the spine, foot or in long tubular bones such as those in the arm or leg, even fingers.

While quite rare in many countries, there has recently been a considerable rise in the numbers of intravenous drug users (IVDUs) becoming infected and this is particularly disturbing considering its often vague initial signs and symptoms which can mean diagnosis is often delayed. This, coupled with the problems IVDUs often encounter when accessing health care can mean that many users are suffering unnecessarily through late diagnosis.

This is a particular concern as some forms of the disease, such as vertebral (spinal) osteomyelitis can, if left untreated, lead to permanent paralysis, significant spinal deformity or even death. It can be an extremely painful infection of the bone and can take some time to heal so it is important for all of us to be aware of osteomyelitis and its symptoms so we know what to look out for. People with compromised immune systems such as cancer or HIV/AIDS, need also be very aware of this debilitating condition as it is often more likely to appear in people whose immune systems are not functioning well.

 

• What is it?
  

Osteomyelitis is usually a secondary infection that follows an infection borne elsewhere in the body - perhaps caused by a wound, (such as an infected abscess), surgery, bone fracture, or a foreign body such as a surgical plate. IV line, urinary catheter or bullet. Once started, the infection can then spread to the bone via the blood and when the bone is infected, pus is produced within the bone. This can result in an abscess, depriving the bone of its blood supply. Early treatment can save the bone from destruction but as bone is hard tissue it is often resistant to antibodies and this can be difficult to treat.

Similar to infective endocarditis (BP issue 7 and BP’s  A-Z of Health), osteomyelitis is usually caused by the same bacteria: Staphylococcus aureus (Staph. a). This bacterium can be introduced into the body in a variety of ways. Staph a. live intermittently on the skin in more than 70% of the population at any one time and the other 14 are colonized persistently. Those who use injecting equipment on a regular basis and inject in sites thai are potentially Staph acolonized such as the feet, hands, groin etc can be at greater risk of attracting infection (see prevention). Again, this is why a hygienic injecting regime is essential for all IV users to help reduce as many factors as possible that could encourage an infection, (see overleaf & BP no. 7).

Osteomyelitis in its acute or direct form is generally more localized, appearing suddenly with symptoms - often prominent and seen within 2 weeks of when the infection starts. With hematogenous (blood borne) osteomyelitis, the symptoms usually take longer to appear - often a month or more and will usually be related to a recent bacteriemic episode (previous infection). In the chronic (persistent) form, the bacteria can live in the bone reducing or cutting off the blood supply, with infections occurring periodically over a lifetime, though this is very rare. You may feel generally unwell, chronically fatigued and/or have non-healing ulcers or sores.

Symptoms

The onset of Osteomyelitis is insidious.
The symptoms include intense pain and a sensation of heat at the site of the affected bone and there are often small areas of tenderness and swelling. It can cause gradually progressing
neck or back pain that increases with movement and can become so severe that it is not relieved by heat, painkillers or even complete bed rest.
Abscesses that contain pus in the tissue surrounding the painful bone, fever and in some cases, fatigue. Irritability, non-healing ulcers, and a restriction of movement in the affected area are also symptoms.

 

Pyogenic (pus forming) vertebral osteomyelitis, as the name suggests,occurs in the spine and is becoming more common in IV users and those suffering from some ailment that involves using injecting devices such as diabetics or those on dialysis. This form of osteomyelitis is more prevalent in the lumbar (lower) region of the spine beeause the infection spreads to the vertebral body by a vascular (venal) route as the veins in the Sower spine drain the pelvis and provide a route of entry for the bacteria to get into the spine. Again, Staphylococcus a. is the organism most likely to infect the spine but for those of us who use drugs IV, the pseudomonas species can also be a common cause of infection.

Non-pyogenic osteomyelitis can be caused by a fungus, yeast or a parasitic organism or even the tuberculosis bacterium (which will sometimes stage itself at the thoracic or middle area of the spine).

Haematogenous (blood borne) osteomyelitis is rare except in IVDUsand the elderly and again, it can be evenmore tricky to diagnose because fever, an elevated white blood eell count (which is the usual signature that an infection is present in the body) and an actual source of infection, can often be lacking.

 

• Diagnosis
  

 

Diagnosis of Osteomyelitis may involve
the following tests.

A blood test may show elevated white
blood cell and ESR (erythrococte sedimentation
rate) counts and blood cultures
could help to identify the causative
organism. However, they may often need
to pull out the big guns in bone scanning
when it comes to diagnosing
osteomyel itis.

A bone scan can indicate an infected bone.

An MRI scan (magnetic resonance
imaging) uses radio waves and a magnet
to produce cross-sectional views of specific
parts of the body and provides detailed information aboutsoft tissue, the
bone marrow and bone marrow tumors.

A computed tomography (CT or CAT)
scan is a type of x-ray image that also
produces cross-sectional views of parts
of the body. The x-ray beam rotates
around the patient who has been injected
with a special dye to help the area of the
body to reflect the x-ray beam

Bone densitometry is a noninvasive
evaluation procedure that uses x-rays to
measure bone mass or the weight of the
skeleton as the amount of bone in it
determines its strength. Bone densitometry
is also used to measure the bone mass
in the spine, hips and arms as these are
the areas most likely to fracture when the
bone mass is low.

Radionuclide bone scan. This method
of diagnosis uses technetium-99, a radioactive
substance which is absorbed by
the tumor. A special camera is then used
to produce an image on a computer in
order to pinpoint its location and can also
detect any spread of the disease into
other organs.

Biopsy. This is a procedure in which a
sample of tissue is removed and sent to a
laboratory for examination by a pathologist.
This may be done in one of two
ways. A needle biopsy uses a hollow needle
to draw tissue from the tumor, whereas
an open biopsy is a surgical procedure
in which an incision is made through the
skin in order to expose the turnor and
allow a sample to be taken.
Once a diagnosis has been made, the
disease may be treated.

 

• Treatment Options
  

Osteomyelitis in less serious cases may be treated without surgery and the first
option is often antibiotics. If this is the case, intravenous antibiotics are administered in hospital and may be continued at home for up to six weeks. Oral antibiotics may be needed for several months. Bracing of the bone and pain-killers may also be required to aid complete recovery.

The basic treatment is all dead, infected and compromised tissue is removed surgically — this includes skin, muscle, tendon, ligaments and, yes, bone. Thereafter, the tissues must rest and recover under the protection of good nutrition, antibiotics and adequate blood flow. Reconstruction is performed when, once again, the wound bed is healthy, clean and viable with the goal to return as much function and form to the extremity as possible. Other methods are:

Free Tissue Transfers: Tissue or bone is moved from another part of your body to reconstruct the extremity. Bone or muscle is moved with its blood supply (artery and vein) and reattaehed to provide healthy tissue to assist healing at the old site of your infection. The tissue moved serves a new purpose and never functions as it did previously.

Bone Grafts: Bone grafts are used to fill defects in bones or to help the ends of bones heal together. Usually the marrow from the inside of the bone is used. Bone graft usually comes either from the back of the pelvis or from the tibia, just beneath the knee. Each site yields a different amount of graft. The site used is based on how much bone is needed.

External Fixators: These are metallic devices used outside the skin to support the bone while it heals. Pins pass from the device, through the skin and into the bone. Most are used for a relatively short time { 4-6months) to hold bones in place until healing is complete.

Herbs may be employed in order to strengthen and tone the body's systems.
There are a number of herbs that can have a beneficial effect such as goldenseal, Barberry and ordinary garlic can fight infection. There are even herbs that relieve pain like St John's wort and valerian. Although very few studies have been undertaken, Homeopathy may also he considered as an option but has to be individually tailored to suit.

Hyperbaric Oxygen Therapy. Hyper (increased) baric (pressure) oxygen therapy means breathing 100% oxygen under increased atmospheric pressure in a specially designed medical device called a hyperbaric chamber. (Michael Jackson sleeps in one!) This is a relatively recent treatment and has had dramatic success in many areas of medicine, not just osteomyelitis. Surgery is often regarded as the last resort but depending on the severity of the disease, it may be the only option available.

Surgery may be necessary in cases of chronic osteomyelitis or when there has been some delay in diagnosis in order to drain abscesses adjacent to the nearest bone and remove all the dead tissue such as the tissue transfers and bone grafts mentioned earlier. The most drastic form of surgery is, of course, amputation but this is only carried out in the most extreme eases.

Prognosis: The prognosis is variable but markedly improved
with timely diagnosis and aggressive therapeutic intervention.

 

• Prevention
  

With Osteomyelitis, because it's usually a secondary infectionthat stems from an infection elsewhere in the body, it really tells us just how important it is to get any infected wounds or abscesses treated immediately and effectively. This is where a
hygenic injecting regime is again essential as if you try and keep your injecting routine as sterile as possible, you will be minimising chances of getting a primary infection, that may then become the source for osteomyelitis to take a hold.
(See A-Z on health for Hygiene Do’s and Don’ts))

 

The direct introduction of osteomyelitis through surgery or the introduction of a foriegn hody such as a plate, IV line, bullet etc can be avoided through the giving of prophylactic antibiotics at the time of injury or surgery, so be sure to ask your doctor about this particularly if you have a compromised immune system.

MYTH! The infection will make other people sick if they
come into contact with it.
FACT: Your infection is not contagious and will not affect
other people unless they are severely immuno-compromised.
Good hand-washing when you change dressings, and a clean
dressing over open wounds should be enough to keep everyone
protected.

MYTH! The infection will continue to spread in the bone
and eventually to the rest of my body.
FACT: Generally osteomyelitis does not spread to other
parts of your body because they are alive and have a blood supply
and your body's immune system to protect them. An exception
to this is if you have artificial joints in other parts of your
body; they are in essence, "dead" and vulnerable to circulating
pathogens. However, leaving osteomyelitis untreated is certain
to give you ongoing, serious problems,

Researched & written by Chris Drouet and Erin O’Mara

If you are concerned about osteomyelitis, contact your GP or
BP for further information or try these websites as a good introductory
source of info:

for more detailed info
check out this site at:
www.emedicine.com/orthoped/topic429.htm