Ischiofemoral space dimensions for ischiofemoral impingement: is it different in children?

Objective This study intended to analyze alterations in ischiofemoral space (IFS) dimensions in normal children between the ages of 1 and 18 years for the ischiofemoral impingement. Materials and methods This study retrospectively focused on computed tomography images of 360 hips of 180 (90 boys and 90 girls) pediatric subjects (mean age: 9.50 +/- 5.20 years, range: 1-18 years) without any hip disorders to measure IFS, femoral neck angle (FNA), and ischial angle (IA). Results Mean IFS, FNA, and IA were measured as 14.64 +/- 7.24 mm, 34.61 +/- 11.47 degrees, and 131.52 +/- 4.22 degrees, respectively. IFS increased in children aged between 1 and 18 years, whereas FNA and IA decreased. IFS was similar in infancy and early childhood periods but then increased up to postpubescent period. FNA decreased proportionally from birth, whereas IA decreased in an irregular pattern. Linear functions were detected as y = 3.451 + 1.178 x years for IFS, as y = 48.555 - 1.468 x years for FNA, and as y = 132.535 - 0.107 x years for IA. Conclusion Our findings indicate that IFS tends to increase in size with age during childhood but decreases with further aging. Therefore, age-specific values for IFS, FNA, and IA may be beneficial for clinicians and radiologists for the diagnosis of ischiofemoral impingement.