For Physiotherapy

2.  An infection of the bone is termed osteomyelitis
(myelo = marrow). A number of systemic infectious
diseases may spread to the bone such as enteric fever,
actinomycosis, mycetoma (madura foot), syphilis,
tuberculosis and brucellosis. However, two of the
conditions which produce significant pathologic
lesions in the bone, namely pyogenic osteomyelitis and
tuberculous osteomyelitis.

3. Pyogenic Osteomyelitis
 Pyogenic or suppurative osteomyelitis is usually caused by
bacterial infection and rarely by fungi. The profile of patients in
developing and developed countries is different:
 ”In the developing countries of the world, it may occur by
haematogenous route, most commonly in the long bones of
infants and young children (5-15 years of age) (called
haematogenous osteomyelitis). On the other hand, in the
developed world, where institution of antibiotics is early and
prompt, haematogenous spread of infection to the bone is
uncommon; instead, direct extension of infection from the
adjacent area, frequently involving the jaws and skull, is more
common mode of spread. Bacterial osteomyelitis may be a
complication at all ages in patients with compound fractures,
surgical procedures involving prosthesis or implants, gangrene of
limb in diabetics, debilitation and immunosuppression.

4.  Though any etiologic agent may cause osteomyelitis,
Staphylococcus aureus is implicated in a vast majority of
cases. Less frequently, other organisms such as
streptococci, Escherichia coli, Pseudomonas, Klebsiella and
anaerobes are involved. Mixed infections are common in
post-traumatic cases of osteomyelitis. There may be
transient bacteraemia preceding the development of
osteomyelitis so that blood cultures may be positive.
 Clinically, the child with acute haematogenous
osteomyelitis has painful and tender limb. Fever, malaise
and leucocytosis generally accompany the bony lesion.
Radiologic examination confirms the bony destruction.

5. MORPHOLOGIC FEATURES
 Depending upon the duration, osteomyelitis may be
acute, subacute or chronic. The basic pathologic
changes in any stage of osteomyelitis are: suppuration,
ischaemic necrosis, healing by fibrosis and bony
repair. The sequence of pathologic changes is as under.

6. 1. The infection begins in the metaphyseal end of the marrow
cavity which is largely occupied by pus. At this stage,
microscopy reveals congestion, oedema and an exudate of
neutrophils.
2. The tension in the marrow cavity is increased due to pus
and results in spread of infection along the marrow cavity,
into the endosteum, and into the haversian and
Volkmann’s canal, causing periosteitis.
3. The infection may reach the subperiosteal space forming
subperiosteal abscesses. It may penetrate through the
cortex creating draining skin sinus tracts.
4. Combination of suppuration and impaired blood supply to
the cortical bone results in erosion, thin

7. 5. With passage of time, there is formation of new bone beneath
the periosteum present over the infected bone. This forms an
encasing sheath around the necrosed bone and is known as
involucrum. Involucrum has irregular surface and has
perforations through which discharging sinus tracts pass.
6. Long continued neo-osteogenesis gives rise to dense sclerotic
pattern of osteomyelitis called chronic sclerosing nonsuppurative
osteomyelitis of Garré.
7. Occasionally, acute osteomyelitis may be contained to a localised
area and walled off by fibrous tissue and granulation tissue. This
is termed Brodie’s abscess.
8. In vertebral pyogenic osteomyelitis, infection begins from the disc
(discitis) and spreads to involve the vertebral bodies

10. Tuberculous Osteomyelitis
 Tuberculous osteomyelitis, though rare in developed
countries, continues to be a common condition in
under-developed and developing countries of the
world. The tubercle bacilli, M. tuberculosis, reach the
bone marrow and synovium most commonly by
haematogenous dissemination from infection
elsewhere, usually from the lungs, and infrequently by
direct extension from the pulmonary or
gastrointestinal tuberculosis.

11. MORPHOLOGIC FEATURES
 The bone lesions in tuberculosis have the same general
histological appearance as in tuberculosis elsewhere and consist
of central caseation necrosis surrounded by tuberculous
granulation tissue and fragments of necrotic bone.
 The tuberculous lesions appear as a focus of bone destruction
and replacement of the affected tissue by caseous material and
formation of multiple discharging sinuses through the soft
tissues and skin. Involvement of joint spaces and intervertebral
disc are frequent. Tuberculosis of the spine, Pott’s disease, often
commences in the vertebral body and may be associated with
compression fractures and destruction of intervertebral discs,
producing permanent damage and paraplegia. Extension of
caseous material along with pus from the lumbar vertebrae to
the sheaths of psoas muscle produces psoas abscess or lumbar
cold abscess.

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