A different perspective for radiological evaluation of experimental osteomyelitis

Radiological scoring systems used in experimental osteomyelitis combine several factors into a single score. Because response of bone tissue to infection is a dynamic process, such systems have limited ability to differentiate between treatment groups. The analyzing of radiological criteria separately at different stages of the disease may be superior to a general score. Osteomyelitis was induced with Staphylococcus aureus in the left tibiae of 72 adult Wistar albino rats. The rats were assigned to one of six different treatment groups. Their radiographs were graded (1) by the use of previously published general scoring systems and (2) by the evaluation of periosteal reaction, bone deformation, diaphyseal widening, osteolysis, soft tissue swelling, bone mineral content (BMC) and bone mineral density (BMD), separately. The assessments were performed 3 weeks after induction as well as 3 weeks and 6 weeks after treatment. Periosteal reaction and diaphyseal widening demonstrated significant differences within 3 weeks of treatment, contrary to the general scores. After 6 weeks of treatment, individual criteria, including diaphyseal widening, osteolysis and BMC but only one of the general grading scores, were able to differentiate between treatment groups. For differentiation of treatments in experimental osteomyelitis individual assessment of radiological criteria is superior to previously published general scoring systems. (orig.)