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

Figure 5 Illustrative longitudinal case of subchondral stress fracture of the femoral head in a 21-year-old recruit. A-D: Initial Stage II imaging demonstrates a left femoral-head subchondral fracture with marked joint effusion and bone marrow edema; E-H: At 17-month follow-up, the femoral head shows collapse and degenerative change, while joint effusion is markedly reduced. This case illustrates a longer interval between examinations and should not be interpreted as evidence of a uniform disease trajectory.