Chronic osteomyelitis is defined as the presence of on-going bone infection for longer than 1 month in the presence of devitalized bone.
The prevalence of chronic osteomyelitis is much higher in developing countries as a consequence of delayed diagnosis and under-treatment of acute hematogenous osteomyelitis.
The most common site of involvement is tibia followed by femur and humerus.
Specific causes are rare like primary immunodeficiency; however, many risk factors are present.
Risk factors are the antecedent focus of infection like otitis media, pharyngitis, sinusitis, tonsillitis, and other factors like trauma, chronic illness, and malnutrition.
The most common mode of spread infection is by hematogenous route, contiguous spread, and followed by direct inoculation.
Staphylococcus aureus is the most common causative organism in chronic osteomyelitis.
A chronic discharging wound is the commonest presenting symptom.
The quality of discharge varies from sero-purulent to thick pus.
There may be a history of extrusion of the small bone fragments.
Pain is usually minimal but may become aggravated during an acute exacerbation.
Generalized symptoms of infection such as fever are present only during the acute exacerbation.
Chronic discharging sinus, which is fixed to the underlying bone, is present. There may be sprouting granulation tissue at the sinus opening.
The sequestrum may be visible at the mouth of the sinus itself.
Mild tenderness, bony thickening, and irregularity are present.
The adjacent joint may be stiff either due to excessive soft tissue scarring around the joint or because of associated arthritis of the joint
Complete blood count, erythrocyte sedimentation rate (ESR), C – reactive protein (CRP), and blood culture are blood investigation routinely performed.
Radiograph of the affected part aids in the evaluation of sequestrum, involucrum, and bone defect.
Sinography can be performed if a sinus track is present and can be a valuable adjunct to surgical planning, from which depth and extent of infection can be determined.
Bone aspirate/ pus culture sensitivity is performed to find out specific organism responsible for the infection.
Computed tomography provides an excellent definition of cortical bone and fair evaluation of surrounding soft tissues and is useful in the identification of sequestra.
Magnetic resonance imaging is more useful for soft tissue evaluation.
Very rarely bone scan is required in complicated complex cases.
Treatment of chronic osteomyelitis is surgical with appropriate antibiotic supplementation.
The goal of treatment is the eradication of causative organisms, elimination of local inflammation & tissue destruction, and restoration of functional anatomy.
Local term consequences of improperly, inadequately, insufficiently treated cases include pathological fracture, growth disturbance, deformities, and rarely amyloidosis, sinus tract malignancy (<1%).