Osteomyelitis

1. Osteomyelitis
SMS3053
Dr.Mohanad R. Alwan

2. What is osteomyelitis?
Osteomyelitis is a progressive infection of bone
or bone marrow, and Surrounding soft tissue
usually caused by pyogenic bacteria.
(most common in staphylococcus aureus)
 It can be usefully subclassified on the basis of
the causative organism, the route, duration and
anatomic location of the infection.
Infection is more common in the long bones and
vertebras, but it can affect any bone in the body.

3. How Common Is Osteomyelitis?
Chronic osteomyelitis occurs in about 2 in
10,000 adults.
Children have the acute form of the
disease more often than adults do, at a
rate of about 1 in 5,000

5. Development of Osteomyelitis

10. Osteomyelitis is infection in the bones.
Often, the original site of infection is elsewhere in the
body, and spreads to the bone by the blood.
Bacteria or fungus may sometimes be responsible for
osteomyelitis.

11. Classification of Osteomyelitis
Pathogenesis
Hematogenous (most common cause in kids)
• In children: tubular bones
• In adults: spine, pelvis and small bones
Spread from adjacent soft tissue infection
• Ex: ulcers, diabetic foot ulcers
Direct inoculation
• Ex: Trauma or surgery
Chronicity
Acute
Subacute
Chronic
Progression to subacute or chronic
disease depends on timing of dx and tx,
comorbid conditions, immune status etc.

12. Acute Osteo Sub-Acute Osteo Chronic Osteo
Begins with marrow
edema, cellular infiltration
and vascular engorgement
May progress to necrosis
and abscess formation
Spread within the
intramedullary cavity 
extension through cortex
by Havers and Volkman’s
canals  subperiosteal
space  periosteum 
soft tissues
Rupture of joint space 
septic arthritis
 Occurs in abnormal bone
or after inadequate
antibiotics
Localized pyogenic
process
Commonly appears as a
well-defined osteolytic
metaphyseal lesion
(Brodie’s abscess) with a
sclerotic margin that fades
peripherally (fuzzy
sclerotic margin)
S. aureus is most common
pathogen
 Occurs after inadequate tx or in
pts with altered immunity
Distinguishing feature is
necrotic bone surrounded by
granulation tissue
Interruption of blood supply 
necrosis  devitalized bone
fragments (sequestra)
A thick sheath of new periosteal
bone can develop around the
sequestra (involucrum)
Fistula tract formation
Sharp interface between normal
and diseased marrow

14. Subacute MRI Findings
Brodie’s abscess
 (intraosseous abscess, internal wall covered by granulation
tissue)
16 y/o with Brodie’s
abscess. T1 weighted
image of the knee (A)
demonstrates the double
line effect, a focal area of
low signal with alternating
bands of high and low
signal.
Axial T2 weighted image
of the proximal tibia at the
same level (B)
demonstrates a region of
high-intensity surrounded
by alternating bands of
low signal and high signal.
Subacute osteo is often confused with
tumor (osteosarcoma, Ewing)

15. Osteomyelitis
Classification of osteomyelitis
1. Haematogenous (Children and aged people).
2. Inoculation osteomyelitis (Bacteria from tissues
nearby) i.e. (from open wounds, operations or
open fractures).
3. Direct or contiguous osteomyelitis is caused by
direct contact of the tissue and bacteria during trauma or
surgery.

16. Haematogenous Osteo.

17. Most common sites of indirect entry in children
Distal femur
Proximal tibia
Humerus
Radius
Most common sites of indirect entry in adults
are Vascular-rich bone sites
Pelvis
Tibia
Vertebrae

18. Pathophysiology of Osteomyelitis
Generally, microorganisms may infect bone
through one or more of three basic methods:
1. Via the bloodstream.
2. Penetrating (trauma).
3. Internal fixation of fractures.

19. PATHOPHYSIOLOGYPATHOPHYSIOLOGY
Microorganisms enter bone (Phagocytosis).
Phagocyte contains the infection
Release enzymes
Lyse bone

20. PATHOPHYSIOLOGYPATHOPHYSIOLOGY
Bacteria escape host defenses by:
Adhering tightly to damage bone
Persisting in osteoblasts
Protective polysaccharide-rich biofilm

21. PATHOPHYSIOLOGYPATHOPHYSIOLOGY
Pus spreads into vascular channels
Raising intraosseous pressure
Impairing blood flow
Chronic ischemic necrosis
Separation of large devascularized fragment
New bone formation
(involucrum)
Often, the body will try to create new bone around the area of necrosis.
(Sequestra)(Sequestra)

22. Pathophysiology of Osteomyelitis
In infants, the infection can spread to the joint and
cause arthritis.
tibia, femur, humerus, vertebra, the maxilla, are
susceptible to osteomyelitis because of the particulars
of their blood supply.
Many infections are caused by Staphylococcus
aureus, a member of the normal flora found on the
skin and mucous membranes.

23. Pathophysiology
(Smeltzer, Bare, Hinkle, & Chever, 2008)

24. Osteomyelitis

25. PATHOLOGYPATHOLOGY
AcuteAcute Infiltration of PMNsInfiltration of PMNs
Congested or thrombosed vesselsCongested or thrombosed vessels
ChronicChronic  Necrotic boneNecrotic bone
Absence of living osteocyteAbsence of living osteocyte
Mononuclear cells predominateMononuclear cells predominate
Granulation & fibrous tissueGranulation & fibrous tissue

26. Osteomyelitis-gross & microscopy

27. Involucrum (new bone)

28. Jose R. Jimenez MD, UTHCT 28

30. Risk factors
Osteomyelitis does not occur more commonly in
a particular race or gender. However, some
people are more at risk for developing the
disease, including:
People with diabetes
Patients receiving hemodialysis
People with weakened immune systems
People with sickle cell disease
Intravenous drug abusers
The elderly
Chronic steroid use

31. Immunosuppression,
 And chronic joint disease.
In addition, the presence of a prosthetic
orthopedic device is an independent risk factor,
as is any recent orthopedic surgery or open
fracture.

32. Etiology and Pathophysiology
ORGANISM POSSIBLE PROBLEM
Staphylococcus aureus Pressure ulcer, penetrating wound,
open fracture, orthopedic surgery,
vascular insufficiency disorder
Staphylococcus epidermidis Indwelling prosthetic device
Streptococcus viridans Abscessed tooth, gingival disease
Escherichia coli Urinary tract infection
Mycobacterium tuberculosis Tuberculosis
Neisseria gonorrhoeae Gonorrhea
Pseudomonas sp. Puncture wounds, intravenous drugs
Salmonella sp. Sickle cell disease
Fungi, mycobacteria Immunocompromised host

33. Osteomyelitis
Infants
Children
Streptococcus B
Staphylococcus
E. coli
Staphylococcus aureus
Streptococcus pyogenous
Hemophilus influenzae

34. Osteomyelitis
Adult
Staphylococcus epidermidis
Staphylococcus aureus
Pseudomonas aeruginosa
E. coli

36. Hematogenous osteomyelitis
Most common in children, especially
premature infants and babies born with
complications. Hip joint destroyed by osteomyelitis

37. HEMATOGENOUS OSTEPMYELITISHEMATOGENOUS OSTEPMYELITIS
Rapidly growing bone
Children:
Long bone, Femur, Tibia, Humerus
Older patients: Vertebral bone

38. HEMATOGENOUS OSTEOMYELITISHEMATOGENOUS OSTEOMYELITIS
Neonate & infant < 1 year oldNeonate & infant < 1 year old
Septic arthritis is common.Septic arthritis is common.
Growth deformities is common.Growth deformities is common.
Soft tissue involvement is common.Soft tissue involvement is common.

39. HEMATOGENOUS OSTEOMYELITISHEMATOGENOUS OSTEOMYELITIS
Children: 1 – 16 years oldChildren: 1 – 16 years old
Most frequent in the metaphysis of long bone.
History of antecedent trauma in 30%
Involucrum
•Part of periosteum that continues to have a blood supply forms new
bone called involucrum
Sequestration
 Devitalized bone separates from living bone
Associated septic arthritis

40. Once outside bone
Sequestrum may
Revascularize and then undergo removal by normal
immune process
Be surgically removed through debridement of
necrotic bone
If necrotic sequestrum is not resolved, it may
develop a sinus tract resulting in chronic,
purulent cutaneous drainage

42. HEMATOGENOUS OSTEOMYELITISHEMATOGENOUS OSTEOMYELITIS
AdultAdult
Less commonLess common
Spread infection to joint space.Spread infection to joint space.
Vertebral Osteomyelitis is common> 50yVertebral Osteomyelitis is common> 50y

43. Clenched fistClenched fist
osteomyelitisosteomyelitis

44. Clinical Manifestations
Acute Osteomyelitis
Initial infection
Infection of <1 month in duration
Both systemic and local
Systemic
Fever, night sweats, chills, restlessness,
nausea, Fatigue, Anorexia

45. Clinical Manifestations
Acute Osteomyelitis
Local
Constant bone pain that worsens with activity
Swelling, tenderness, warmth at infection site
Restricted movement of affected part
Later signs: drainage from sinus tracts

46. Failure to thrive
Drowsy
Irritable
Metaphyseal tenderness
Decrease ROM (range of motion)

47. Clinical Manifestations
Chronic Osteomyelitis
Bone infection lasting longer than a month
Infection that has failed to respond to
initial course of antibiotic therapy
Systemic signs may be diminished
Local signs of infection more common
Constant bone pain
Swelling, tenderness, warmth at infection site

48. Acute Osteomyelitis Differential
Diagnosis
Cellulitis
Acute septic arthritis
Acute rheumatism
Sickle cell crisis
Gaucher’s disease

49. Osteomyelitis
Diagnosis
Complete medical history
Physical examination
Full body examination and local tenderness.

50. Lab
C-Reactive Protein
Elevated WBC count
Erythrocyte sedimentation rate (ESR)

51. Diagnostic Methods
Bone or soft tissue biopsy
Definitive way to determine causative
microorganism
Patient’s blood and/or wound culture
Frequently positive for presence of
microorganism
Elevated WBC count
Erythrocyte sedimentation rate (ESR)

52. Diagnostic Methods
Radiologic signs
Usually do not appear until 10 days to weeks after
start of clinical symptoms
Radionuclide bone scans
Helpful in diagnosis and usually positive in areas of
infection
Magnetic resonance imaging (MRI)
Computed tomography (CT)
Help identify extent of infection, including soft tissue
involvement

53. Osteomyelitis
Ultrasound
Fast diagnosis
Possible punction
Abscess

54. MRI of Acute Osteomyelitis
15 y/o with knee pain and acute
osteomyelitis. Coronal image shows
low signal intensity in the proximal
epiphysis extending through the
growth plate into the metaphysis of the
tibia.

55. Osteomyelitis
Bone scan
Positive reply within 2-3 days.
Non-specific – other changes with increased
bone metabolism can give the same signs.
 Bad resolution – no details are shown

56. Osteomyelitis
MRI
Early diagnosis – better than bone scan.
Good because it shows soft tissue changes
Abscess

57. Osteomyelitis
Bacteriologic diagnosis
Blood culture.
Local culture.
 Needle biopsy.

58. Complications
Septicemia/ Bacteremia
Metastatic infection
Septic arthritis
Altered bone growth
Chronic osteomyelitis

59. COMPLICATIONCOMPLICATION
Bone abscess
Fracture
Loosing of the prosthetic implant
Overlying soft-tissue cellulitis
Draining soft-tissue tract

60. Spondylitis (Vertebral osteomyelitis)
Back pain in elderly people.
Fever.
Engages two vertebras and disc in between
Caused by (Staph aureus).

61. Treatment
Primarily non-operative.
Surgery to improve local environment by
remove infected bone and soft tissue.
Decompressing abscess cavity.
Facilitate antibiotic delivery.

62. TREATMENTTREATMENT
Indication for SurgeryIndication for Surgery
Hip joint involvement
Neurologic complication
Poor or no response to IV therapy
Sequestration

63. Treatment
Antibiotic therapy
Bacteriologic diagnosis.
Specific general antibiotic treatment.
Local antibiotics.

64. Antibiotic therapy
Early treatment important (after culture)
Intravenous broad-spectrum Anti biotic until
pain relief and clinical improvement (1-2 w).
Oral antibiotics followed, often combination.

65. • Extensive debridement was carried
out. Debris and dead bone were
removed, and antibiotic cement beads
were placed.
• In this case, as in all cases of
suppurative osteomyelitis, surgical
debridement is primary, and
antiobiotic treatment is supporitive.

66. Antibiotic therapy
Antibiotics changed after culture and clinical course
Staph aureus
Streptococcus Penicillin G
Follow CRP, ESR and leukocytes.
Duration of Ab treatment at least 4 - 6 w after
normalized CRP
Cloxacillin,
Rifampicin

67. b

68. PROGNOSISPROGNOSIS
Is related to:Is related to:
Causative organismsCausative organisms
Duration of symptoms & signDuration of symptoms & sign
Patient agePatient age
Duration of antibiotic therapyDuration of antibiotic therapy

69. CONTIGUOUS-FOCUSCONTIGUOUS-FOCUS
OSTEOMYELITISOSTEOMYELITIS

70. Osteomyelitis
In adults, osteomyelitis is usually a sub acute
or chronic infection that develops secondary to
an open injury to bone and surrounding soft
tissue.

71. Contiguous-focus OsteomyelitisContiguous-focus Osteomyelitis
Clinical setting:Clinical setting:
Postoperative infectionPostoperative infection
Contamination of boneContamination of bone
Contiguous soft tissue infectionContiguous soft tissue infection
Puncture woundsPuncture wounds

72. Contiguous-focus OsteomyelitisContiguous-focus Osteomyelitis
Microbiologic featuresMicrobiologic features
StaphylococciStaphylococci  Aureus, EpidermidisAureus, Epidermidis
Gram-negative bacteriaGram-negative bacteria
Anaerobic infectionAnaerobic infection
Unusual organismsUnusual organisms Clostridia, NocardiaClostridia, Nocardia

73. Contiguous-focus OsteomyelitisContiguous-focus Osteomyelitis
DiagnosisDiagnosis
Leukocyte countLeukocyte count
Blood culture (infrequently positive)Blood culture (infrequently positive)
ESR & CRPESR & CRP
Radiologic evaluationRadiologic evaluation
Technetium bone scanTechnetium bone scan
Open bone biopsyOpen bone biopsy
Culture of woundCulture of wound

74. Contiguous-focus OsteomyelitisContiguous-focus Osteomyelitis
TreatmentTreatment
Surgery is essential.Surgery is essential.
AntibioticsAntibiotics

75. The End