2. Osteomyelitis
• Etiology
• Bacteria are the most common pathogens
• Staphylococcus aureus is the most common infecting organism in all age
groups
• GBS and Escherichia coli - neonates
• After 6 yr of age- caused by S. aureus, streptococcus, or Pseudomonas
aeruginosa
• Pseudomonas infection - puncture wounds of the foot
• Salmonella species ,S. pneumoniae and S. aureus - children with sickle cell
anemia
3. Etiology….
• A microbial etiology is confirmed in ∼60% of cases of osteomyelitis.
• Blood cultures are positive in ∼50% of patients
• Prior antibiotic therapy and the inhibitory effect of pus on microbial
growth might explain the low bacterial yield
4. Epidemiology
• The median age is ∼6 yr
• The incidence of in children is estimated to be 1 : 5,000.
• More common in boys than girls
• The majority of osteomyelitis cases in previously healthy children are
hematogenous
• Minor closed trauma is a common preceding event in cases of osteomyelitis,
occurring in ∼30% of patients.
• Infection of bones can follow penetrating injuries or open fractures
• Bone infection following orthopedic surgery is uncommon
• Impaired host defenses also increase the risk of skeletal infection
6. Pathogenesis
• In the metaphysis, nutrient arteries branch into nonanastomosing
capillaries under the physis
• Blood flow in this area is “sluggish,” predisposing to bacterial invasion
• Once a bacterial focus is established, phagocytes migrate to the site
and produce an inflammatory exudate (metaphyseal abscess)
7. Pathogenesis….
• As the inflammatory exudate progresses, pressure increases spread
through the porous metaphyseal space via the haversian system and
Volkmann canals into the subperiosteal space.
• Purulence beneath the periosteum may lift the periosteal membrane
of the bony surface, further impairing blood supply to the cortex and
metaphysis
• In newborns and young infants, transphyseal blood vessels connect
the metaphysis and epiphysis, so it is common for pus from the
metaphysis to enter the joint space
8. Clinical Manifestations
• The earliest signs and symptoms of osteomyelitis, often subtle and
nonspecific, are generally highly dependent on the age of the patient.
• Neonates might exhibit pseudoparalysis or pain with movement of
the affected extremity (e.g., diaper changes).
• Older infants and children are more likely to have fever, pain, and
localizing signs such as edema, erythema, and warmth.
• With involvement of the lower extremities, limp or refusal to walk is
seen in approximately half of patients.
9. Clinical Manifestations….
• Pelvic osteomyelitis can manifest with subtle findings such as hip,
thigh, or abdominal pain
• Long bones are principally involved in osteomyelitis
• femur and tibia are together constitute almost half of all cases
• Upper extremities account for one fourth of all cases.
• Flat bones are less commonly affected
10. Clinical Manifestations…
• There is usually only a single site of bone or joint involvement.
• Several bones are infected in <10% of cases; the exception is
osteomyelitis in neonates,
• Children with subacute symptoms and focal finding in the
metaphyseal area (usually of tibia) might have a Brodie abscess, with
radiographic lucency and surrounding reactive bone.
11. Diagnosis
• The diagnosis of osteomyelitis is clinical; blood cultures should be
performed in all suspected cases
• aspiration or biopsy of bone or subperiosteal abscess for Gram stain,
culture, and bone histology
• No specific laboratory tests for osteomyelitis
• WBC,ESR, orCRP are elevated
12. Diagnosis….
• Radiographic Evaluation
• Radiographic studies play a crucial role in the evaluation of
osteomyelitis
• MRI has emerged as the most sensitive and specific test and is widely
used for diagnosis
• long bones do not show lytic changes for 7-14 days after onset of
infection
• Infection in flat and irregular bones can take longer to appear.
13. Diagnosis….
• MRI is more sensitive than CT or radionuclide imaging in acute
osteomyelitis and is the best radiographic imaging technique for
identifying abscesses and for differentiating between bone and soft-
tissue infection
• Radionuclide imaging can be valuable , especially early in the course
of infection and/or multiple foci
14. Differential Diagnosis
• cellulitis or trauma (accidental or abuse)
• Myositis or pyomyositis
• Appendicitis, urinary tract infection, and gynecologic disease
• leukemia
• Neuroblastoma
• Primary bone tumors
15. Treatment
• Optimal treatment of skeletal infections requires collaborative efforts
of pediatricians, orthopedic surgeons, and radiologists.
• Antibiotic Therapy
• The initial empirical antibiotic therapy is based on knowledge of likely
bacterial pathogens at various ages, the results of the Gram stain of
aspirated material, and additional considerations.
16. Treatment….
• Duration of antibiotic therapy is individualized depending on the
organism isolated and clinical course.
• For most infections including those caused by S. aureus, the minimal
duration of antibiotics is 21-28 days, a total of 4-6 wk of therapy may
be required.
• Changing antibiotics from the intravenous route to oral
administration when a patient's condition clearly has improved and
the child is afebrile for ≥48-72 hr, may be considered.
17. Treatment….
• Surgical Therapy
• When frank pus is obtained from subperiosteal or metaphyseal
aspiration surgical drainage usually indicated
• Treatment of chronic osteomyelitis consists of surgical removal of
sinus tracts and sequestrum, if present.
• Antibiotic therapy is continued for several months or longer until
clinical and radiographic findings suggest that healing has occurred.
• Physical Therapy
• The major role of physical medicine is a preventive one
18. Prognosis
• When pus is drained and appropriate antibiotic therapy is given, the
improvement in signs and symptoms is rapid
• Recurrence of disease and development of chronic infection after
treatment occur in <10% of patients
• Long-term follow-up is necessary with close attention to range of
motion of joints and bone length
19. Septic Arthritis
• In infants and children has the potential to cause permanent disability
•Etiology
Haemophilus influenzae type b accounted for more than half of all
cases
Staphylococcus aureus - in all age groups
S. pneumoniae is most likely in the first 2 years of life
Group B streptococcus - in neonates
Fungal infections - as part of multisystem disease
20. Epidemiology
• More common in young children
• Half of all cases occur by 2 yr of age and 3/4 of all cases occur by 5 yr
of age
• Adolescents and neonates are at risk of gonococcal septic arthritis
• The majority of infections in otherwise healthy children are of
hematogenous origin
21. Epidemiology….
• Infection of joints can follow penetrating injuries , arthroscopy,
prosthetic joint surgery, intra-articular steroid injection, and
orthopedic surgery
• Immunocompromised patients and those with rheumatologic joint
disease are also at increased risk of joint infection
22. Pathogenesis
• Septic arthritis primarily occurs as a result of hematogenous seeding
• Less often, organisms enter the joint space by direct inoculation or
extension from a contiguous focus.
• Synovial and cartilage destruction results from a combination of
proteolytic enzymes and mechanical factors.
23. Clinical Manifestations
• Most septic arthritises are monoarticular
• The signs and symptoms depend on the age of the patient
• Early signs and symptoms may be subtle
• In neonates and young infants is often associated with adjacent
osteomyelitis
• Older infants and children might have fever and pain, with localizing
signs
• joints of the pelvis and lower extremities, limp or refusal to walk is
often seen
• Erythema and edema of the skin and soft tissue overlying the site
24. Clinical Manifestations
• Septic arthritis of the hip is an exception because of the deep location
of the hip joint
• Joints of the lower extremity constitute 75% of all cases of septic
arthritis
• The elbow, wrist, and shoulder joints are involved in about 25% of
cases
25. Diagnosis
• Blood cultures
• Aspiration of the joint fluid and anlysis
• white blood cell count and differential, ESR, and CRP
• Radiographic studies play a crucial role in evaluating septic arthritis.
• Conventional radiographs, ultrasonography, CT, MRI, and radionuclide
studies can all contribute to establishing the diagnosis
26. Treatment
• Optimal treatment of septic arthritis requires cooperation of pediatricians,
orthopedic surgeons, and radiologists to benefit the patient.
• Antibiotic Therapy
• The initial empirical antibiotic therapy is based on likely pathogens at
various ages, Gram stain
• Duration of antibiotic therapy
Ten to 14 days is usually adequate for streptococci, S. pneumoniae, and K.
kingae;
longer therapy may be needed for S. aureus and gram-negative infections
Oral antibiotics can be used to complete therapy once the patient is
afebrile for 48-72 hr
27. Treatment….
• Surgical Therapy
• Infection of the hip is generally considered a surgical emergency
because of the vulnerability of the blood supply to the head of the
femur
• For joints other than the hip, daily aspirations of synovial fluid may be
required
28. Prognosis
• When pus is drained and appropriate antibiotic therapy is given, the
improvement in signs and symptoms is rapid.
• Failure to improve or worsening by 72 hr requires review of the
appropriateness of the antibiotic therapy, the need for surgical
intervention
• Recurrence and chronic infection after treatment occur in <10% of
patients.
