Type I: Open, exposed bone without evidence of osseous infection but with evidence of soft tissue infection;

Type II: Circumferential, cortical, and endosteal infection; x-ray showing a diffuse inflammatory reaction, increased density, and spindle shaped sclerotic thickening of the cortex in addition to areas of bone resorption; often an involucrum surrounding a sequestrum;

Type III: Cortical & endosteal infection assoc w/ a segmental bone defect