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

Figure 1 Participant flow diagram. A total of 242 inpatient records were screened. Sixty-eight records were excluded: Incomplete electronic medical records (n = 5), traumatic femoral head osteochondral fractures (n = 8), transient osteoporosis (n = 6), rapidly destructive arthropathy (n = 2), femoroacetabular impingement syndrome (n = 41), and other non-stress-fracture/non-osteonecrosis of the femoral head (ONFH) conditions (n = 6). The final analysis included 174 patients (220 hips): 127 patients with subchondral stress fracture of the femoral head (139 hips) and 47 patients with ONFH (81 hips). Diagnostic-group classification was based on blinded magnetic resonance imaging review. SSFFH: Subchondral stress fracture of the femoral head; ONFH: Osteonecrosis of the femoral head.