osteoperiostitis

Osteoperiostitis is a descriptive term referring to inflammation affecting both the bone (osteo) and the periosteum, the connective tissue layer that covers bone. It is not a single disease but a pattern of inflammation that can accompany various underlying conditions, most notably infectious osteomyelitis, but also noninfectious processes that irritate the periosteum or the cortex.

Causes and associations include infection (acute or chronic osteomyelitis with periosteal involvement), trauma, inflammatory or autoimmune disorders, vascular insufficiency, and neoplastic or metabolic conditions that stimulate periosteal new bone formation. The periosteum is particularly reactive to irritation, and subperiosteal new bone formation may occur in response to ongoing inflammation, injury, or tumor growth.

Pathophysiology typically involves inflammation of the periosteum with secondary involvement of the underlying bone. This can lead to edema, pain, and tenderness, with the periosteum lifting away from the cortex and new bone forming along the surface. Chronic or severe inflammation may result in structural changes or damage to the cortical bone.

Clinical features are usually localized to the affected site and may include bone pain, tenderness, swelling, and warmth. Fever and systemic signs may be present if infection is the cause. Laboratory tests often show elevated inflammatory markers, and imaging may reveal a periosteal reaction, subperiosteal collections, or other bone changes. MRI and CT can help delineate soft tissue involvement and the extent of bone damage.

Treatment centers on addressing the underlying cause, such as antibiotics for infection, surgical debridement if indicated, and management of pain and inflammation. Prognosis varies with etiology and timeliness of treatment.