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136 Haematogenous Osteomyelitis and Septic Arthritis

rate (ESR) is elevated in 80–90% of cases, and the C-reactive protein Table 22.1: Classification and treatment system for haematogenous
(CRP) is elevated in 98% of cases. Blood cultures are often positive in osteomyelitis in developing world children.
children presenting with systemic sepsis. None of these tests, however, Classification Characteristics Treatment
are specific for HO, and therefore must be used only to supplement the Stage 1 Local and systemic signs. Incision and drainage.
history and physical examination. Indeed, many African hospitals will Acute No bone changes on Antibiotics for 2–6 weeks.
not have these laboratory tests available. The most accurate method x-ray (less than 2-week
for determining whether osteomyelitis is present is a bone marrow history).
aspiration with stains and cultures to determine the infecting organism. Stage 2 Undrained acute Surgical drainage and
Plain radiography, early in the clinical course, may show soft tissue Acute with osteomyelitis (2–8 week debridement of obviously
x-ray changes
history). Local and maybe dead bone only.
swelling and obliteration of tissue planes. After 10–14 days from systemic signs with bone Perioperative antibiotics.
onset of the symptoms, bone resorption is demonstrated by irregular destruction on x-ray and
patches of radiolucency in the metaphysis, and periosteal elevation no clear sequestrum.
is demonstrated by an outside rim of reactive new bone formation. Stage 3 Long history of Wide drainage and
In chronic osteomyelitis, plain radiographs may demonstrate lytic Chronic localised osteomyelitis, usually with removal of sequestra.
Antibiotics not required.
persistent spontaneous
areas of the bone, sequestrum formation, or pathologic fractures. The drainage. No systemic
TA technetium 99m bone scan is a sensitive (84–100%) and specific symptoms.
(70–90%) test for acute osteomyelitis, and magnetic resonance imaging Stage 4 Chronic osteomyelitis Urgent wide drainage,
(MRI) is the best special imaging study. However these studies are not Chronic systemic with systemic removal of sequestra,
available in most African health care facilities. manifestations. and administration of
antibiotics until systemic
Classification manifestations resolve.
Traditionally, the stages of HO have been described as: (1) acute, (2)
chronic, and (3) subacute. This traditional classification, however, is
not very practical for use in LWATs. As a result, African practitioners
have developed alternative classification systems. 10–11 The classification
system shown in Table 22.1 was developed in a Nigerian general medi-
cal practice hospital in 1993.
12
This simplified and functional system classifies children at the time
of initial diagnosis of HO into one of four stages based on symptoms,
signs, and x-ray findings. In stage 1 HO (acute), there is pus in the
medullary canal and perhaps subperiosteally. There are usually local
and systemic signs, but no significant x-ray changes that would
demonstrate bone destruction or the presence of sequestra. Bone
destruction and sequestra formation do not usually result in significant
x-ray changes for at least 2 weeks into the HO process. Therefore,
stage 2 HO (acute with x-ray changes) begins around 2 weeks into
the process and indicates that significant bone destruction has already
taken place. Children with stage 3 HO (chronic localised) have usually Figure 22.2: Neglected HO resulting in (A) chronic draining sinuses secondary
suffered an acute bout of HO that has drained spontaneously or has been to (B) a large sequestrum.
operatively drained at a health care facility. However the sequestrum,
which has not resorbed nor been surgically removed, serves as a nidus advanced technology, treatment for children with osteomyelitis is simi-
for chronic draining sinuses or recurrent abscesses (Figure 22.2). lar to that in Western hospitals. Early acute osteomyelitis is managed
If a significant abscess occurs around the sequestrum and does not nonoperatively with a culture of the medullary contents and prolonged
spontaneously drain, the child becomes systemically septic and reaches organism-appropriate intravenous antibiotics until the infection has
stage 4 HO (chronic systemic). This Nigerian staging system will be been totally eradicated. Many other hospitals in Africa, however, are
used throughout this chapter due to its practicality in areas with limited resource poor, and this section on treatment is directed more towards
diagnostic and therapeutic resources. these hospitals.
Differential Diagnosis Appropriate treatment, particularly in LWATs, depends on the stage
Bone infarction can be difficult to differentiate from infection in a child of HO when the child presents and the resources (antibiotics, operative
with sickle cell disease. In both situations, children present with fever capabilities) physically and economically accessible in the particular
and bone pain and have elevated inflammatory markers. Biopsy and location where the child presents. The best microbiological study
culture of affected bone is often necessary to establish the diagnosis. available may be a gram stain. Surgical instruments, if available at all,
Cellulitis of soft tissues may restrict movement and cause the child to are usually quite basic. Appropriate antistaphylococcal antibiotics may
limp, but in most cases swelling and erythema of the skin are obvious. be totally unavailable or may be so expensive that parents are faced
A fracture also causes swelling, pain, tenderness, and increased warmth with the difficult decision of providing antibiotics for one child for a
of an extremity and may be differentiated from HO only by the history week or feeding the rest of the children in the family for the next several
(although most children with HO also have a history of trauma) and months. Health providers must therefore consider these painfully
more definitively by an x-ray. Neoplasms, especially leukaemia and realistic socioeconomic factors in recommending appropriate practical
Ewing’s sarcoma, may be confused with osteomyelitis and may require treatment for a particular child with HO. The basic components of
a biopsy for the correct diagnosis. optimal treatment for HO are: (1) drainage of the pus under pressure,
(2) acute antibiotics to treat systemic sepsis, (3) removal of nonviable
Treatment bone, (4) sterilisation of the medullary contents with local or systemic
All African hospitals are not equal. Many, particularly university hos- techniques, and (5) wound closure. Unlike the current nonoperative
pitals in major African cities, have state-of-the-art facilities comparable treatment of HO in locations with advanced technology, operation is
to those in Western hospitals. As a result, in African hospitals with