Osteomyelitis
Osteomyelitis: Excerpt from The 5-Minute Pediatric Consult
Mitchell R.M. Schwartz, MDAaron Donoghue, MD (4th Edition)
Osteomyelitis - BASICS
Osteomyelitis - description
Infection of the bone: Femur and tibia are most often affected.
Osteomyelitis - epidemiology
Osteomyelitis - incidence
Incidence of 0.016% per year
Osteomyelitis - risk factors
- Immunocompromised patients
- Increased incidence in patients with sickle cell disease and other immunodeficiencies
Osteomyelitis - pathophysiology
- Usually, osteomyelitis begins as bacteremia with hematogenous spread to the bone, but direct inoculation of bacteria into the bone by trauma is also possible.
- Most bacteria that enter the bone are phagocytized, so that no infection develops. When bacteria enter areas of the bone with low blood flow, however, such as the metaphysis directly beneath the physeal plate, they may not be phagocytized, and an infection may develop.
- The 1st changes noted in osteomyelitis are the death of the osteoblasts in the infected area and resorption of trabeculae. Inflammation develops, which further compromises blood flow, and microabscesses are formed within the bone. Pus can spread through the bone and between the bone and the periosteum. This pus can lift the periosteum, causing point tenderness.
Osteomyelitis - etiology
- Staphylococcus aureus causes 90% of osteomyelitis in otherwise healthy children of all ages.
- Streptococcus pyogenes or Haemophilus influenzae can also be the etiologic agent.
- Group B streptococci and Escherichia coli are often isolated in children <1 month of age.
- Salmonella can be the cause in children with sickle cell anemia.
- Pseudomonas aeruginosa can be found in puncture wounds to the foot.
Osteomyelitis - DIAGNOSIS
Osteomyelitis - signs & symptoms
- Physical examination usually reveals a febrile child with point tenderness over the area of infected bone. The child is often unwilling to move the involved extremity.
- As the infection progresses, swelling, warmth, and erythema of the skin overlying the infection may be noted.
- An infant with osteomyelitis may appear septic.
- A child with osteomyelitis usually complains of sudden onset of bone or joint pain and fever.
- A younger child may refuse to bear weight on or move the extremity that is involved.
Osteomyelitis - tests
Osteomyelitis - lab
- Patients usually have an elevated WBC count and a high ESR.
- C-reactive protein (CRP) levels are usually elevated and are useful for monitoring response to therapy.
- Blood cultures are positive for infection in >50% of patients.
Osteomyelitis - imaging
- Plain films begin to show the changes of osteomyelitis 10–14 days into the infection, with periosteal elevation and bone destruction.
- 99Tc bone scans are 80% accurate, and gallium scans are thought to be 91% accurate in diagnosing osteomyelitis.
- MRI can be useful in defining abscesses and extent and anatomy of bone sequestra; it is also the most useful imaging study for delineating chronic osteomyelitis.
Osteomyelitis - diag proced-surgery
Aspiration of the infected bone, even in the absence of débridement, is useful for determining the etiologic organism.
Osteomyelitis - differencial diagnosis
- Caution:
- Delayed diagnosis
- Difficulty distinguishing osteomyelitis from a sickle cell crisis
- Cellulitis
- Septic arthritis
- Inflammatory arthritis or juvenile rheumatoid arthritis
- Malignancy
- Trauma
- Sickle cell crisis
- Toxic synovitis
Osteomyelitis - TREATMENT
Osteomyelitis - general measures
- Antibiotic therapy for 4–6 weeks is usually required.
- IV oxacillin is usually the empiric drug of choice until an organism can be isolated.
- Gram-negative coverage should be added for neonates, and Salmonella species coverage is needed in sickle cell patients.
- If a recent foot puncture wound was experienced, coverage for Pseudomonas species is recommended.
- After the organism is known and sensitivities are established, the patient may be switched to oral antibiotics, as long as the serum bactericidal titer can be maintained.
- If an abscess is present in the bone, surgical débridement may also be necessary.
Osteomyelitis - FOLLOW UP
Patients should be followed to ensure adequate treatment of infection and continued growth of the extremity involved.
Osteomyelitis - complications
Permanent damage to the growth plate, septic arthritis, fracture in a weakened bone
Osteomyelitis - bibliography
- Barron SA. Index of suspicion. Case I. Diagnosis: Osteomyelitis. Pediatr Rev. 1998;19:51–52.
- Dirschl DR. Acute pyogenic osteomyelitis in children. Orthop Rev. 1994;5:305–312.
- Fink CW, Nelson JD. Septic arthritis and osteomyelitis in children. Clin Rheum Dis. 1986;12:423.
- Mandell GA. Imaging in the diagnosis of musculoskeletal infections in children. Curr Prob Pediatr. 1996;26:218–237.
- Roine I, Faingezicht I, Arguedas A, et al. Serial serum C-reactive protein to monitor recovery from acute hematogenous osteomyelitis in children. Pediatr Infect Dis J. 1995;14:40–44.
- Roy DR. Osteomyelitis. Pediatr Rev. 1995;16:380–384, 385 (quiz).
- Sonnen GM, Henry NK. Pediatric bone and joint infections: Diagnosis and antimicrobial management. Pediatr Clin North Am. 1996;43:933–947.
- Wall EJ. Childhood osteomyelitis and septic arthritis. Curr Opin Pediatr. 1998;10:73–76.
Osteomyelitis - CODES
Osteomyelitis - icd9
730.2 Osteomyelitis
Osteomyelitis - FAQ
- Q: Do you need to surgically débride osteomyelitis?
- A: This is a very controversial topic. Many physicians believe that all osteomyelitis should be surgically débrided, whereas others believe that, in the absence of an abscess, antibiotic therapy alone is adequate. Most agree, however, that if an abscess is present, it should be drained.
- Q: Will osteomyelitis cause permanent damage in the bone?
- A: If the growth plate is not damaged and the infection is adequately treated, there should be no permanent sequelae of osteomyelitis. If the growth plate is damaged, however, the affected limb may not grow evenly, or at all, even after the infection is treated.
- Q: Is CRP a more useful laboratory study than ESR for osteomyelitis?
- A: The CRP level is known to respond more quickly to changes in the inflammatory state than the ESR, reflecting changes in as short a period as 6–8 hours. Studies have shown that the CRP normalizes sooner in osteomyelitis than does the ESR, and studies have also shown that a persistently high CRP is a better indicator than ESR of inadequate therapy, the need for repeated drainage procedures, worsened radiographic appearance, and symptoms of greater duration.
>
Book Source Details
- Book Title: The 5-Minute Pediatric Consult
- Author(s): M. William Schwartz MD; et al.
- Year of Publication: 2008
- Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.
More About Osteomyelitis
More Medical Textbooks Online about Osteomyelitis
Review other book chapters online related to Osteomyelitis:
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
|
|
More About This Book:
Title: The 5-Minute Pediatric Consult
Authors: M. William Schwartz MD; et al.
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7577-9
|
|
» Next page: Surveys relating to Osteomyelitis
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
