When bacterial virulence is low or the host's immune response is strong, an abscess can become encapsulated within the bone, forming a localized intraosseous abscess known as Brodie abscess. This condition typically occurs in the metaphysis of long bones, most commonly affecting the tibia, femur, and humerus. The contents of the abscess vary over time: initially consisting of purulent inflammatory fluid, followed by inflammatory granulation tissue during the intermediate phase, and eventually evolving into infected scar tissue in the later stages.
There is generally no history of acute suppurative osteomyelitis, and symptoms are not prominent at onset. The disease course often spans several years, with episodes of acute symptoms triggered by physical exertion or minor trauma. During acute episodes, localized pain and increased skin temperature may be present, although redness of the skin is rare. These inflammatory symptoms usually subside rapidly following the use of antibiotics. In a small number of cases, when the inflammation cannot be controlled, skin ulceration and pus discharge may occur.
Laboratory tests typically show no particular abnormalities. X-ray imaging reveals cystic lesions within the bone surrounded by sclerotic bone. During acute exacerbations, systemic antibiotic therapy is administered. Cases with recurrent episodes require surgical intervention, which is performed after acute inflammation has been brought under control. Antibiotics are used both before and after the surgery. The surgical procedure involves the complete removal of inflammatory tissue from the lesion, thorough irrigation, and filling of the cavity with cancellous bone graft material. Autologous cancellous bone from the iliac crest is reduced into small granules with a bone rongeur and mixed with antibiotic powder for filling the cavity. The wound is then sutured, and primary healing is generally achieved.