What is Bone Infection (Osteomyelitis)?
Osteomyelitis is the medical term for infected bone.
Infected bone can occur in any bone in the body, but is more commonly associated with an area of bone near a site of previous injury or surgery. It can also occur spontaneously without known injury or disease.
How is it Treated?
Osteomyelitis is treated in the same manner as other body infections - by using antibiotics. However, the treatment of bone infection may also involve surgery.
Antibiotics are delivered to infected areas of the body by the blood circulation, but infection of bone may render the bone weak or even cause the infected area of bone to die.
Dead bone has an impaired or absent blood supply, so it can be difficult to treat bone infection with antibiotics alone if the blood supply does not penetrate the diseased area.
This may mean that to treat your bone infection, we may need to remove dead or infected bone and improve the circulation to the diseased area.
What does Soft Tissue Infection mean?
Soft tissue infection may also be present with bone infection. When we talk about soft tissue, we are generally referring to skin, fat, muscle and their connective tissues. Soft tissue infection may be obvious as with an open wound or hole in the skin (called a sinus). Sometimes soft tissue infection is not obvious until the time of surgery.
How do I know if there is an Infection Present?
During your operation, Mr Khan may take some tiny samples of bone and tissue. These are sent to Pathology. The Pathology Laboratory uses the samples taken by Mr Khan and through various means of equipment will attempt to determine whether there is a bacteria growing in the samples and if so the type of bacteria.
Once this information is known, Mr Khan can determine which antibiotic is required, which route of administration is required and the length of the course.
The length of your course of antibiotics will depend on the results from Pathology.
It will take 5 to 7 days for the results to be final and during this time Mr Khan may prescribe a broad-cover antibiotic for you.
When the final culture results are known, your antibiotics will be prescribed specifically to treat the bacteria grown in the surgical samples. The length of the antibiotic course can vary.
The most common length of a course of antibiotics to treat Osteomyelitis is a 6 weeks course given intravenously followed by a long course of tablet antibiotics. Antibiotic therapy can be administered orally, that is by taking tablets or can be administered intravenously, that is, given directly into your veins.
Mr Khan will advise you on the best possible course of treatment tailored to your individual needs and results. Following your surgery, you may be started on intravenous antibiotics. These are given through a plastic intravenous cannula placed into a small vein in the back of your hand or lower forearm. The cannula used is called a Venflon.
Venflons tend to only last for a day or so of treatment. Each time another venflon is required, we will insert a new venflon in a different area that you can continue to take your course of intravenous antibiotics.
When we are sure that you require a long course of intravenous antibiotics we will advise you to have a central intravenous line inserted.
The most common type of central line that is used is called a PICC line. This is inserted by a specially trained doctor or nurse.
A local anaesthetic cream is applied over the veins in your elbow crease. This will numb the skin. A venflon is then inserted into the vein in the elbow crease. Using the venflon as a hollow tube, the nurse or doctor will insert the PICC line through the venflon. The line follows the inside of the vein into a central vein. (Central veins are located in your chest.) The venflon is then removed.
A chest x-ray is then performed to ensure the PICC line is in a central vein. Once verified by Mr Khan, the PICC line is ready for use. These PICC lines are designed to last for periods lasting up to 6 months.
How is Osteomyelitis Surgery Performed?
Removal of Metalwork at Infected Non-Union sites: A non-union site is where your original fracture (sometimes held with metalwork) has not healed. This may be due to a variety of reasons, but at the time of surgery Mr Khan will take samples of the bone at the non-union site to look for signs of infection. If the non-union site has metalwork present, Mr Khan may need to remove this metalwork at the time of surgery.
Osteomyelitis Surgery: The infected portion of bone is either Debrided or Removed completely. Debridement of bone involves scraping away diseased bone until healthy bone is reached. Dead or infected bone may need to be removed completely. Depending on the bone involved and the strength requirements of the bone, the limb may need to be supported, protected or held in a secure position after the operation.
You may be asked not to put any weight through the limb for a period of time. If your surgery is on your leg, you may be asked to use elbow crutches or another walking aids. If your surgery is to your arm, you may be asked not to carry anything heavier than a piece of paper.
You may need to wear a plastic splint on your limb or a specially made plaster of Paris cast.
If the bone is unstable or requires complex reconstruction Mr Khan will apply an external fixator device to your limb.
How does Plastic Surgery help?
If a large area of Osteomyelitis or soft tissue has to be removed during the surgery, then a second procedure may be required to fill the space left by the surgery and also improve the blood circulation.
Dependant on the bone and soft tissue area involved and the strength requirements of the bone affected, a variety of methods may be used.
Examples of this second procedure involving Plastic Surgery are:
1. Small areas with surrounding healthy tissue can be left and will fill and heal eventually with no other intervention required.
2. Muscle flaps can be used to fill and correct both soft tissue and bone gaps within the body. These flaps are not visible externally on the limb. They improve the circulation to the area therefore assisting the antibiotics to penetrate the area. Mr Khan will remove a muscle from another area of your body, usually from an area local to the surgical area. (Mr Khan always attempts to transfer a muscle that by its removal alone should not affect your day-to-day performance)
3. Muscle flaps can be used to fill soft tissue gaps in a limb where infected skin and muscle have had to be removed. This not only improves the circulation but ensures that the operated area is completely protected with the new soft tissue, improving the blood supply, filling the gap and preventing secondary infection from the outside (atmosphere) into the surgical area.
When used this way the muscle flap is covered with a layer of skin graft. The skin graft is usually taken from your thigh. The surgeon tries to take into account the final resulting shape and appearance of the area of the limb but it often takes a few months for the muscle flap to flatten to the same shape as your limb.
4. Plastic Surgery may also involve using bone transferred from one area of your body to another to fill a gap in the bone.
This may involve using bony chips usually taken from the part of your hip called the Iliac Crest. This is the area of your hips that stick out at the front, above your groins. The bony chips are then used to fill small gaps in bone.
5. The second procedure involves using larger sections of bone. This procedure is used in Limb Reconstruction when the amount of lengthening required is more than we can offer by using the frame alone.
An example of this procedure is explained. A larger piece of bone is taken (usually from the fibula, the smaller leg bone, below the knee) and transferred with its own blood supply into the area of your limb where you need living bone. This is called Live Bone Transplant.
It involves “plumbing” the transplanted bone (usually the Fibula) Arteries and Veins together into the new area requiring bone. In the picture the transplant bone is the Fibula and it is “plumbed” into the upper arm (or Humerus’) Arteries and Veins.