Osteomyelitis; Causes, Symptoms, Diagnosis, Treatment

Types of Osteomyelitis

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.

1.  Suppurative osteomyelitis

• Acute? suppurative osteomyelitis
• Chronic? suppurative osteomyelitis
  • Primary (no preceding phase)
  • Secondary (follows an acute phase)

2.  Non-suppurative osteomyelitis

• Diffuse sclerosing
• Focal sclerosing (condensing osteitis)
• Proliferative periostitis (periostitis ossificans, Garré’s sclerosing osteomyelitis)
• Osteoradionecrosis

OM can also be typed according to the area of the skeleton in which it is present. For example, osteomyelitis of the jaws is different in several respects from osteomyelitis present in a long bone. Vertebral osteomyelitis is another possible presentation.

According to the severity

• Acute osteomyelitis – In acute osteomyelitis, infection develops within 2 weeks of an injury, initial infection, or the start of an underlying disease. The pain can be intense, and the condition can be life-threatening.
• Sub-acute osteomyelitis – In sub-acute osteomyelitis, infection develops within 1–2 months of an injury, initial infection, or the start of an underlying disease.
• Chronic osteomyelitis – In chronic osteomyelitis, infection starts at least 2 months after an injury, initial infection, or the start of an underlying disease.

3.  According to the pathogen or bones

Long bone

• The acutely febrile and bacteraemic patient presents with a markedly painful, immobile limb.
• There may be swelling? and extreme tenderness? over the affected area with associated erythema? and warmth.
• The pain is exacerbated by movement and there may be sympathetic effusion of neighbouring joints.
• In neonates and infants, there may be an associated septic arthritis?.
• Occasionally, the patient may present with mild? symptoms, perhaps a history of blunt trauma? to the area which may or may not be remembered (eg, a bump against a hard surface) 24-48 hours previously and mild or no pyrexia.
• There may be nonspecific systemic malaise attributed to a viral? illness and suspicions are only raised as the symptoms localise after several days.

Vertebral

This usually presents insidiously following an acute septicaemic episode:

• There may be localised oedema, erythema and tenderness ± associated contiguous vascular insufficiency.
• Alternatively, these patients can present with chronic back pain? which is worse at rest and unremitting in nature.
• They may specifically complain of night pain. It may be associated with nonspecific malaise.

Pott’s disease

• Pott’s disease refers to vertebral osteomyelitis resulting from the haematogenous spread of tuberculosis?.
• There is damage to the bodies of two neighbouring vertebrae?, leading to vertebral collapse and subsequent abscess formation? (known as a ‘cold abscess?’).
• Pus? can track out from there into adjacent structures, leading to systemic symptoms of malaise, fever and night sweats?.

4.   Classification: Waldvogel System

Causes of Osteomyelitis

Most cases of osteomyelitis are caused by staphylococcus bacteria, types of germs commonly found on the skin or in the nose of even healthy individuals.

Germs can enter a bone in a variety of ways, including:

• The bloodstream – Germs in other parts of your body — for example, in the lungs from pneumonia? or in the bladder from a urinary tract infection — can travel through your bloodstream to a weakened spot in a bone. In children, osteomyelitis most commonly occurs in the softer areas, called growth plates, at either end of the long bones of the arms and legs.
• Infected tissue or an infected prosthetic joint – Severe puncture wounds can carry germs deep inside your body. If such an injury becomes infected, the germs can spread into a nearby bone.
• Open wounds – Germs can enter the body if you have broken a bone so severely that part of it is sticking out through your skin. Direct contamination can also occur during surgeries to replace joints or repair fractures.
• From an adjacent infection – Sometimes deep wounds transmit germs far inside the body. If a wound becomes infected, germs can spread to nearby bone.
• Direct infection – This can happen if a bone breaks so severely that it is exposed to open air. Direct infection can also happen during some surgeries to replace a joint or repair a fracture.
• Through a wound on the skin, muscles or tendons
• After a fracture in which the ends of the bone pierce the skin
• Through the bloodstream from an infection in another part of the body
• After surgery on the bone, especially if the surgery involved placement of metal hardware
• After an ear or sinus infection, if the infection spreads to surrounding bones or soft tissues (this is called skull base osteomyelitis)
• Destruction of bone
• Periosteal new bone formation

Organisms of Osteomyelitis

• Newborns
  • S. aureus
  • Group B streptococcus
  • E. coli
• Children
  • S. aureus
• Adults
  • S. aureus (most common)
  • Enteric species
  • Streptococcus
• Drug addicts
  • Pseudomonas (most common)
  • Klebsiella
• Sickle cell disease
  • Salmonella

Pathogenesis

• Hematogenous spread
• Direct implantation from a traumatic / iatrogenic source
• Extension from adjacent soft-tissue infection

The most affected bones

• Lower extremity (most common)
  • Over pressure points in diabetic foot
• Vertebrae
  • Lumbar  > thoracic > cervical
• Radial styloid
• Sacroiliac joint

Symptoms of Osteomyelitis

the first symptom to appear is pain at the infection site. Other common symptoms are:

• A sudden high temperature (fever) of 38°C (100.4°F) or above, although this symptom is often absent in children under one year old
• Bone pain, which can often be severe
• Swelling, redness and warmth at the site of the infection
• A general sense of feeling unwell
• The affected body part is tender to touch
• The range of movement in the affected body part is restricted
• Lymph nodes (glands) near the affected body part may be swollen
• Fever and chills
• Redness in the infected area
• Irritability or generally feeling unwell
• Drainage from the area
• Swelling in the affected area
• Stiffness or inability to use an affected limb

or

Symptoms of osteomyelitis might include the following

• Fever, sweating and chills
• Bone pain or tenderness
• Severe back pain
• Swelling and redness at the infection site
• Swelling of ankles, feet and legs
• Lethargy, malaise or irritability
• Headaches
• Pain around the eye or ear
• Hearing loss or ringing in the ear
• Dizziness
• Facial weakness or paralysis
• Double vision
• Hoarseness
• Difficulty swallowing

Diagnosis of Osteomyelitis

Blood tests

• Complete blood count (CBC) – The doctor will draw blood to run a complete blood count (CBC) to determine if there is an infection in the body. If an infection is present, the number of white blood cells will be elevated. This is because white blood cells attack and destroy the organisms causing the infection.
• Erythrocyte sedimentation rate (ESR) – the doctor will draw blood to run an ESR to determine how much inflammation is in the body. ESR is useful in detecting a bone infection.
• C-reactive protein (CRP) – the doctor will draw blood to run a CRP to determine how much inflammation is in the body. CRP is useful in detecting an infection.
• Radioisotopic bone scanning – a diagnostic procedure that uses nuclear imaging to help monitor several types of bone disease, including bone infections.

Imaging tests of Osteomyelitis

If osteomyelitis is suspected, it is likely you will be referred for further imaging testing. There are several imaging tests that may be able to detect bone damage caused by osteomyelitis

• X-rays – where low levels of radiation are used to create an image of the affected bone – this test is not usually useful for diagnosis if the condition is in the early stages.
• Magnetic resonance imaging (MRI) – where a strong magnetic field and radio waves are used to build up a picture of the inside of the affected bone . A diagnostic procedure that uses a combination of large magnets, radio frequencies, and a computer to produce detailed images of organs and structures within the body.
• Computerised tomography (CT) scan – where a series of X-rays of your affected bone are taken and a computer is used to assemble them into a more detailed three-dimensional image
• Ultrasound scan – where high-frequency sound waves are used to create an image of the affected bone to highlight any abnormalities
• Biopsy – If earlier testing suggests osteomyelitis, it is usually necessary to remove a small sample of bone for further testing. This is known as a biopsy.A biopsy is usually necessary to confirm a diagnosis of osteomyelitis and can help establish the exact type of bacteria or fungus causing your infection. This can be very useful when deciding on the most effective treatment.
• Blood Cultures  A test in which a sample of your blood will be checked for bacteria and germs that may be causing the infection.
• Needle aspiration – A process where a needle is used to take a sample out of your bones to look for an osteomyelitis infection.

Treatment of Osteomyelitis

• Antibiotics – Cultures of bone, blood, or pus from a wound will guide your doctor’s choice of antibiotic medications. Antibiotics are usually given for four to six weeks. In most cases antibiotics will be given by IV at first. After some time has passed, antibiotic treatment may be switched to pills.
• NSAID – to relief pain as aspirin, acetaminophen, ibuprofen  and naproxen can offer short-term relief. All are available in low doses without a prescription. Other medications, including muscle relaxants and anti-seizure medications, treat aspects of spinal stenosis, such as muscle spasms and damaged nerves.
• Corticosteroid injections – Your doctor will inject a steroid such as prednisone into your back or neck. Steroids make inflammation go down. However, because of side effects, they are used sparingly.
• Anesthetics – Used with precision, an injection of a “nerve block” can stop pain for a time.
• Muscle Relaxants: These medications provide relief from spinal muscle spasms.
• Neuropathic Agents: Drugs(pregabalin & gabapentine) that address neuropathic—or nerve-related—pain. This includes burning, numbness, and tingling.
• Calcium & vitamin D3 – to improve bones health and healing fracture.
• Glucosamaine & diacerine – can be used to tightening the loose tenson and regenerate cartilage or inhabit the further degeneration of cartilage.
• Diatery suppliment -to remove the general weakness & improved the health
• Hyperbaric oxygen treatment (HBOT) – If you have chronic osteomyelitis and you are not responding to other treatments, or the osteomyelitis involves bones of your spine, skull, or chest, your doctor may order HBOT. This treatment involves staying in a chamber that increases the pressure around your body and allows your lungs to absorb pure oxygen. More oxygen in your blood and tissues helps you fight infection and heal faster. You may need about 100 minutes of this treatment a day for about five weeks for HBOT to be effective.

Surgery of Osteomyelitis

• Draining – The area around the infected bone may need opening up for the surgeon to drain any pus or fluid that has built up in response to the infection.
• Debridement – The surgeon removes as much diseased bone as possible, and takes a small margin of healthy bone to ensure that all the infected areas are removed. Any surrounding tissue with signs of infection may also need removing.
• Restoring blood flow to the bone – Any empty space left by debridement may have to be filled with a piece of bone tissue, or skin or muscle from another part of the body. Temporary fillers can be used until the patient is healthy enough for a bone or tissue graft. The graft helps the body repair damaged blood vessels, and it will form new bone.
• Removal of foreign objects – If necessary, foreign objects placed during previous surgery may be removed, such as surgical plates or screws.
• Stabilizing the affected bone – Metal plates, rods, or screws may be inserted into the bone to stabilize the affected bone and the new graft. This may be done later. Occasionally external fixators are used to stabilize the affected bone.

References