Subchondral stress fractures of the femoral head associated with military training: Clinical features and analysis

Figure 4 Illustrative longitudinal case of subchondral stress fracture of the femoral head in a 20-year-old recruit. A-D: Initial Stage II imaging demonstrates a right femoral-head subchondral fracture with marked joint effusion and bone marrow edema; E-H: At 6-month follow-up, the femoral head shows collapse and degenerative change, while joint effusion is markedly reduced. This case illustrates that structural progression may coexist with reduction of selected magnetic resonance imaging fluid-related abnormalities; it is illustrative and does not establish the natural history of the cohort.