Mirels proposed a scoring system based on four characteristics: (1) site of lesion; (2) nature of lesion; (3) size of lesion; and (4) pain. All the features were assigned progressive scores ranging from 1 to 3 (Table 1).
Mirels’ scoring system
Site of lesion includes three categories: upper extremity, lower extremity, and peritrochanteric area of femur (peritrochanteric). These sites were assigned increasing scores from 1 to 3, respectively. It is commonly believed that lesions in the peritrochanteric area are high risk for fracture [6]. It is also believed chances of pathologic fractures are greater for weightbearing bones than for nonweightbearing bones [15]. However, in Mirels’ original investigation, these commonly held beliefs were not confirmed and site of lesion did not independently predict a fracture [12].