Bone infections OSTEOMYELITIS (Acute, subacute and chronic) Etiology Pathophysiology Presentation Diagnosis Management and complications Osteomyelitis has long been one of the most difficult and challenging problems confronted by orthopaedic surgeons. Currently, morbidity and mortality from osteomyelitis are relatively low because of modern treatment methods, including the use of antibiotics and aggressive surgical treatment.

1. Bone infections
(Osteomyelitis)
DR SETH JOTHAM (GS,PG-2)
CUHAS

2. Outline
Bone infections
• OSTEOMYELITIS
(Acute, subacute and chronic)
Etiology
Pathophysiology
Presentation
Diagnosis
Management and complications

3. OSTEOMYELITIS
• Osteomyelitis has long been one of the most difficult and challenging
problems confronted by orthopaedic surgeons.
• Currently, morbidity and mortality from osteomyelitis are relatively
low because of modern treatment methods, including the use of
antibiotics and aggressive surgical treatment.

4. Classification of osteomyelitis
• Classification of osteomyelitis is based on numerous criteria, such as
the duration and mechanism of infection and the type of host
response to the infection
• Osteomyelitis is traditionally classified (based on symptoms
duration):
 Acute
Subacute
Chronic

5. • The mechanism of infection can be exogenous or hematogenous.
Exogenous osteomyelitis is caused by open fractures, surgery
(iatrogenic), or contiguous spread from infected local tissue.
The hematogenous form results from bacteremia.
• Osteomyelitis also can be classified, based on the host response to
the disease.
Pyogenic or
Non-pyogenic

6. 1. Acute hematogenous osteomyelitis
• Acute hematogenous osteomyelitis is the most common type of bone
infection and usually is seen in children.
• Acute hematogenous osteomyelitis is more common in males in all
age groups affected.
• It is caused by a bacteremia, which is a common occurrence in
childhood.
• The causes of bacteremia are many. Bacteriologic seeding of bone
generally is associated with other factors such as localized trauma,
chronic illness, malnutrition, or an inadequate immune system.
• In many cases, the exact cause of the disease cannot be identified.

7. • In children, the infection generally involves the metaphyses of rapidly
growing long bones. Bacterial seeding leads to an inflammatory
reaction, which can cause local ischemic necrosis of bone and
subsequent abscess formation.
• As the abscess enlarges, intramedullary pressure increases causing
cortical ischemia, which may allow purulent material to escape
through the cortex into the subperiosteal space.
• A subperiosteal abscess then develops, If left untreated it culminates
with formation of chronic osteomyelitis.

8. • Generally affecting children younger than age 2 years and children
between the ages of 8 to 12 years.
• Half of all children with osteomyelitis are younger than 5 years of age.
• The effects of osteomyelitis in children vary with age based on
differences in blood supply and the anatomic structure of the bone.
• In children younger than 2 years, some blood vessels cross the physis
and may allow the spread of infection into the epiphysis.
• For this reason, infants are susceptible to limb shortening or angular
deformity if the physis or epiphysis is damaged by infection.

9. • Otherwise, the physis acts as a barrier that prevents the direct spread
of a metaphyseal abscess into the epiphysis.
• The metaphysis has relatively fewer phagocytic cells than the physis
or diaphysis, allowing infection to occur more easily in this area.

10. • In children older than 2 years, the physis effectively acts as a barrier
to the spread of a metaphyseal abscess.
• Because the metaphyseal cortex in older children is thicker, the
diaphysis is at greater risk in these patients.
• If the infection spreads into the diaphysis, the endosteal blood supply
may be jeopardized.
• With a concurrent subperiosteal abscess, the periosteal blood supply
is damaged and can result in extensive sequestration and chronic
osteomyelitis if not properly treated.

11. Relevant anatomy

12. …

13. • After the physes are closed, acute hematogenous osteomyelitis is
much less common.
• Hematogenous seeding of bone in adults is often seen in a
compromised host.
• Although it can occur anywhere and in any part of the bone, generally
the vertebral bodies are affected. In these patients, abscesses spread
slowly and large sequestra rarely form.
• If localized destruction of cortical bone occurs, pathologic fracture
can result

14. Infection spread
• Spread of infection to a contiguous joint also is affected by the patient’s
age.
• In children younger than 2 years, the common blood supply of the
metaphysis and epiphysis crosses the physis and can allow spread of a
metaphyseal abscess into the epiphysis and eventually into the joint.
• The hip joint is the most commonly affected in young patients; however,
the physes of the proximal humerus, radial neck, and distal fibula also are
intraarticular, and infection in these areas can lead to septic arthritis as
well.
• In severe infection, epiphyseal separation can occur in children younger
than 2 years

15. ...
• In older children, this common circulation is no longer present, and
septic arthritis is less common.
• After the physes are closed, infection can extend directly from the
metaphysis into the epiphysis and involve the joint.
• Septic arthritis resulting from acute hematogenous osteomyelitis is
generally seen only in infants and adults.

16.  Single pathogenic organism hematogenous osteomyelitis,
 Multiple organisms direct inoculation or contiguous focus infection.
 Staphylococcus aureus ---most commonly isolated pathogen.
 gram-negative bacilli and anaerobic organisms are also frequently isolated
In infants:
Staphylococcus
aureus
Streptococcus
agalactiae
Escherichia coli
In children over one year
of age:
Staphylococcus
aureus,
Streptococcus
pyogenes
Haemophilus
influenzae1
Staphylococcus aureus is
common organism
isolated.2
Etiology
1.Song KM, Sloboda JF. Acute hematogenous osteomyelitis in children. J Am Acad
Orthop Surg. 2001;9:166-75
2.Lew DP, Waldvogel FA. Osteomyelitis. N Engl J Med. 1997;336:999-1007

17. …
• Pseudomonas is the most common infecting organism found in
intravenous drug abusers with osteomyelitis.
• Fungal osteomyelitis is seen increasingly in chronically ill patients
receiving long-term intravenous therapy or parenteral nutrition.
• Salmonella osteomyelitis has long been associated with sickle cell
hemoglobinopathies.
(This infection tends to be diaphyseal rather than metaphyseal)

18. Osteomyelitis of tibia in sickle cell patient

19. Pathogenesis:
Direct inoculation of
microorganisms into bone
penetrating injuries and
surgical contamination are
most common causes
Hematogenous spread
usually involves the
metaphysis of long
bones in children or the
vertebral bodies in
adults
Osteomyelitis
Microorganisms
in bone
Contiguous focus of infection
seen in patients with severe
vascular disease.

20. Pathogenesis..
Whatever may be the inciting cause the bacteria reaches the
metaphysis of rapidly growing bone & provokes an inflammatory
response.
why metaphysis is involved
1. Infected embolus is trapped in U-shaped small end arteries located
predominantly in metaphyseal region
2. Relative lack of phagocytosis activity in metaphyseal region
3. Highly vascularised region ---minor trauma—hemorrhage ----locus
minoris resistantae---excellent culture medium

21. …. These are end-artery branches of the nutrient artery
Obstruction
Avascular necrosis of bone
tissue necrosis, breakdown of bone
acute inflammatory response due to infection
Squestra formation
Chronic osteomyelitis

22. Diagnosis

23. Hx ad P/E
• Signs and symptoms can vary significantly.
• In infants, elderly patients, or immunocompromised patients, clinical
findings may be minimal.
• Fever and malaise may or may not be present in the early stages of
the disease
• With up to 40% of children reportedly afebrile upon hospital
admission, but pain and local tenderness are common findings.
• Swelling may be significant, and compartment syndrome has been
reported in children.

24. LAB
• The white blood cell count is often normal, but the erythrocyte
sedimentation rate and C-reactive protein level are usually elevated.
• The C-reactive protein is a measurement of the acute-phase response
and is especially useful in monitoring the course of treatment of acute
osteomyelitis because it normalizes much sooner (t1/2=19hrs) than
the erythrocyte sedimentation rate (weeks to month).

25. Radiology
• X-ray films are negative within 1-2 weeks
• Careful comparison with the opposite side may show abnormal soft
tissue shadows.
• It must be stressed that x-ray appearances are normal in the acute
phase. There are little value in making the early diagnosis.
• By the time there is x-ray evidence of bone destruction, the patient
has entered the chronic phase of the disease.

26. MRI
• Although the sensitivity of MRI for the diagnosis of osteomyelitis is
high (approximately 98%), the specificity is much lower (around
75%).
• Nearly 60% of uncomplicated septic joint effusions demonstrated
abnormal marrow signal intensity that was mistaken for
osteomyelitis.

27. Bone scans
• Technetium-99m bone scans can confirm the diagnosis 24 to 48 hours
after onset in 90% to 95% of patients
• A negative technetium-99m bone scan effectively rules out the
diagnosis of osteomyelitis.
• Gallium scans and indium- 111-labeled leukocyte scans can also aid in
diagnosis when used in conjunction with technetium scanning.

28. Bone scan showing increased uptake in area of osteomyelitis

29. USS
• Ultrasonography has been used for differentiating acute
hematogenous osteomyelitis from cellulitis, soft-tissue abscess,acute
septic arthritis, and malignant bone tumors in children;
• However, this modality is highly operator-dependent, with a
diagnostic accuracy of only about 60%.
• Labbé et al. noted that although ultrasonography only detected
osteomyelitis in 64% on the day of admission, by the second day, it
positively diagnosed 84%.

30. RX
• The choice of antibiotic is based on the highest bactericidal activity,
the least toxicity, and the lowest cost.
• analgesiccs

31. 2. Subacute Hematogenous Osteomyelitis
• Compared with acute osteomyelitis, subacute hematogenous
osteomyelitis has a more insidious onset and lacks the severity of
symptoms, which makes the diagnosis of this disorder difficult.
• Subacute osteomyelitis is relatively common, reported to occur in
over a third of patients with primary bone infections.
• Currently, no definitive guidelines exist for diagnosis, and
recommendations are based on expert opinions and case series.

32. …
• Because of the indolent course of subacute osteomyelitis, diagnosis
typically is delayed for more than 2 weeks.
• Systemic signs and symptoms are minimal. Temperature is only
mildly elevated if at all. Mild-to-moderate pain is one of the only
consistent signs suggesting the diagnosis.
• White blood cell counts generally are normal. The erythrocyte
sedimentation rate is elevated in only 50% of patients, and blood
cultures usually are negative.
• Even with an adequate bone aspirate or biopsy specimen, a pathogen
is identified only 60% of the time.
• Plain radiographs and bone scans generally are positive

33. …
• The indolent course of subacute osteomyelitis is thought to be the
result of:
increased host resistance,
Decreased bacterial virulence, or
The administration of antibiotics before the onset of symptoms.
It is speculated that the combination of an organism of low virulence
with a strong host response may allow the inflammation to persist in
bone without producing significant signs or symptoms. Nevertheless,
correct diagnosis largely depends on clinical suspicion and radiographic
findings

34. BRODIE ABSCESS
• A Brodie abscess is a localized form of subacute osteomyelitis that
occurs most often in the long bones of the lower extremities of young
adults
• Before physeal closure, the metaphysis is most often affected. In
adults, the metaphyseal-epiphyseal area is involved.
• Intermittent pain of long duration is the presenting complaint, along
with local tenderness over the affected area.

35. …
• On plain radiographs, a Brodie abscess generally appears as a lytic
lesion with a rim of sclerotic bone but it can have a markedly varied
appearance.
• MRI can be helpful in the diagnosis because a Brodie abscess can be
easily mistaken for a variety of neoplasms on plain radiographs.

36. Brodie abscess in right distal tibial epiphysis of
3-year-old child.

37. …
• Organisms of low virulence are believed to cause the lesion. S. aureus
is cultured in 50% of patients; in 20%, the culture is negative.
• This condition often requires an open biopsy with curettage to make
the diagnosis.
• The wound should be closed loosely over a drain.

38. 3. Chronic Osteomyelitis
• Chronic osteomyelitis is difficult to eradicate completely. Systemic
symptoms may subside, but one or more foci in the bone may contain
purulent material, infected granulation tissue, or a sequestrum
• The hallmark of chronic osteomyelitis is infected bone within a
compromised soft-tissue envelope.
• The infected foci within the bone are surrounded by sclerotic,
relatively avascular bone covered by a thickened periosteum and
scarred muscle and subcutaneous tissue.
• This avascular envelope of scar tissue leaves systemic antibiotics
essentially ineffective.

39. • Eradication of chronic osteomyelitis generally requires aggressive
surgical debridement and dead-space management combined with
effective antibiotic treatment.
• Consider an ambulatory immunocompromised host with multiple
medical problems, including chronic osteomyelitis of the femur.
• For this patient, who might not survive the extensive surgical stress
required to eradicate the disease, less aggressive alternatives should
be considered.

40. • Limited surgical debridement combined with suppressive antibiotics
and nutritional support may limit the frequency of sinus drainage and
pain in these difficult cases.
• The treatment course and definition of outcome success must be
individualized for each patient.
• Malignant transformation of chronic osteomyelitis has been reported,
albeit rarely now.

41. • Although this complication is declining, it still occurs, and new signs of
a chronic draining sinus, increased pain, and foul smell should raise
the index of suspicion and biopsy should be considered.
• Squamous cell carcinoma is the most frequent malignancy reported,
and definitive treatment is wide local excision or amputation
combined with chemotherapy and radiation.
(Transformation 1.6%)
M.pantel,DW;Mallignant osteomyelitis recognition and transformation in
chronic principles of management.22(9)(2014),pp.586-594

42. .

43. Diagnosis
• The diagnosis of chronic osteomyelitis is based on clinical, laboratory,
and imaging studies.
• The “gold standard” is to obtain a biopsy specimen for histologic and
microbiologic evaluation of the infected bone.
• Risk factors for polymicrobial osteomyelitis include advanced age,
farm injuries, Gustilo type III injuries, need for blood transfusions, and
need for multiple debridements.
• A higher rate of osteomyelitis after long-bone fractures in patients
with obesity has also been reported

44. P/E
Physical examination should focus on:
The integrity of the skin and soft tissue
Determine areas of tenderness
Assess bone stability
And evaluate the neurovascular status of the limb.

45. Chronic Osteomyelitis of the Femur

46. LAB
• Laboratory studies generally are nonspecific and give no indication of
the severity of the infection.
 Erythrocyte sedimentation rate and C-reactive protein are elevated
in most patients,
But the white blood cell count is elevated in only 35%.

47. RADIOLOGY
• Multiple imaging studies are available to evaluate chronic
osteomyelitis; however, no technique can absolutely confirm or
exclude the presence of osteomyelitis.
• Imaging studies should be done to aid in confirmation of the
diagnosis and to prepare for surgical treatment.
• Plain radiographs can yield valuable information in establishing a
diagnosis of chronic osteomyelitis and should be the initial study
performed.
• Signs of cortical destruction and periosteal reaction strongly suggest
the diagnosis of osteomyelitis.

48. SEQUESTRUM
PERIOSTEAL NEW BONE
FORMATION
INVOLUCRUM

49. • Sinography can be performed if a sinus track is present and can be a
valuable adjunct to surgical planning

50. RX
• Chronic osteomyelitis generally cannot be eradicated without surgical
treatment.
• Antibiotics alone can rarely eradicate the infection for numerous
reasons:
Bacteria are able to adhere to orthopaedic implants and bone matrix
through various receptors.
Some can hide intracellularly.
Others can form a slimy coat that protects them from phagocytic cells
and antibiotics.

51. • Surgery for chronic osteomyelitis consists of sequestrectomy and
resection of scarred and infected bone and soft tissue.
• For soft-tissue and dead-space management, ring external fixators
generally are used after radical debridement.
• The goal of surgery is eradication of the infection by achieving a viable
and vascular environment.
• Radical debridement often is required to achieve this goal. An
oncologic approach of wide excision should be taken because success
of treatment depends on adequacy of debridement

52. Nade’s principles
I. An appropriate antibiotic is effective before abscess formation
II. Antibiotics do not sterilize avascular tissues or abscesses, and such
areas require surgical removal
III. If such removal is effective, antibiotics should prevent their
reformation, and primary wound closure should be safe
IV. Surgery should not damage further already ischemic bone and soft
tissue
V. Antibiotics should be continued after surgery.

53. Nade’s indications for surgery
1. Abscess formation
2. Severely ill & moribund child with features of acute osteomyelitis
3. Failure to respond to IV antibiotics for >48 hrs

54. POSTOPERATIVE CARE
• A long leg posterior plaster splint is applied with the foot in a neutral
position, the ankle at 90 degrees, and the knee at 20 degrees of
flexion.
• When the wound has healed, the splint is remove and protected
weight bearing with crutches is begun.
• The patient is placed on antibiotics based on culture sensitivities.
• Generally, a 6-week course of intravenous antibiotics is given.
• Orthopaedic and infectious disease follow-up is continued for at least
1 year.

55. PAPINEAU ET AL.; ARCHDEACON AND MESSERSCHMITT)

56. SCLEROSING OSTEOMYELITIS OF GARRÉ
• Sclerosing osteomyelitis is a chronic form of disease in which the
bone is thickened and distended but abscesses and sequestra are
absent
• The disease affects children and young adults. Its cause is unknown,
but it is thought to be an infection caused by a low-grade, possibly
anaerobic bacterium.
• The condition must be distinguished from osteoid osteoma and Paget
disease

57. Presentation
• Patients report intermittent pain of moderate intensity and usually of
long duration.
• Swelling and tenderness over the affected bone may be found.
Radiography
• Radiographs show an expanded bone with generalized sclerosis.

58. .

59. LAB
• The erythrocyte sedimentation rate usually is slightly elevated.
• Biopsy specimens show only chronic, low-grade, nonspecific
osteomyelitis, and cultures usually are negative
RX
• No treatment has been predictably helpful, but fenestration of the
sclerotic bone and antibiotics are advisable.

60. AMPUTATION FOR OSTEOMYELITIS
• Amputation is performed infrequently for osteomyelitis. In certain
patients, this form of treatment may be preferable, however, to
multiple operations and prolonged antibiotic therapy
• The prevalence of malignancy arising from chronic osteomyelitis has
been reported to be 0.2% to 1.6%. Most of these are squamous cell
carcinoma arising from a sinus track but fibrosarcoma, and other
malignancies have been reported.

61. …
Amputation is the most reliable means of treating osteomyelitis
associated with:
Malignant change
Arterial insufficiency,
Major nerve paralysis
Joint contractures and stiffness that make a limb nonfunctional

62. References
• Campbell’s operative orthopaedics 14th Ed
• Apley & Solomon’s system of orthopaedics and trauma 10th Ed
• Essential orthopaedics 5th Ed
• M.pantel,DW;Mallignant osteomyelitis recognition and
transformation in chronic principles of
management.22(9)(2014),pp.586-594