Adapting the Fredericson tibial stress fracture grading system to this femoral stress fracture, what grade would you give it?
Grade 4a (Intracortical and marrow edema without defined fracture line)
Axial and coronal T1 and STIR images demonstrate edema in the distal, medial femoral diaphysis periosteum, cortex, and bone marrow. Smooth bony callus overlies the area of edema. No definite fracture line is seen.