Asymmetry of the teardrop sign may indicate occult acetabular fracture. Teardrop sign should be assessed: it marks the convergence of the pubis, the ischium, and the ilium. Location of the femoral head medial to the pectineal line indicates acetabular bone loss or possible medial femoral head migration in the acetabulum. On each side, the line is drawn from the medial border of the iliac wing to the medial border of the ischium, ending at the ischial tuberosity ( Fig. Ilioischial line: this line represents the posterior column. Disruption indicates anterior column fracture ( Fig. It divides the pelvis into major (false) and minor (true) pelvis. Iliopectineal line: this line extends posteriorly from the sacral promontory, arcuate line, and ends anteriorly at the pectineal line. Positive crossover sign indicates presence of femoroacetabular impingement or developmental dysplasia of the hip. In acetabular retroversion, anterior and posterior walls cross each other. The acetabular walls: the posterior wall should be lateral to the anterior wall. The obturator foramen should be symmetric bilaterally. Iliac crests should both be on the same level. Arcuate lines should be symmetrical angular lines indicate sacral fracture. Sclerosis and joint space narrowing characterize sacroiliitis. Normal sacroiliac joint appears as a thin white line. The sacroiliac joint widths should be equal. The symphyseal joint space should be ≤ 5 mm. The pubic symphysis should be in line with the center of the sacrum. 1, coccyx 2, pubic symphysis 3, sacrum 4, sacroiliac joint 5, iliac crests 6, obturator foramen 7, acetabular sourcil 8, teardrop 9, superior pubic ramus 10, inferior pubic ramus 11, ischial ramus 12, ala of ilium 13, fifth lumbar vertebrae 14, fourth lumbar vertebrae 16, lesser trochanter 17, greater trochanter. 1, the fifth lumbar vertebrae 2, sacrum 3, iliac crest 4, ilium 5, anterosuperior iliac spine 6, anteroinferior iliac spine 7, acetabulum 8, superior pubic ramus 9, obturator foramen 10, ischial tuberosity 11, pubic symphysis 12, fovea 13, lesser trochanter 14, shaft of femur 15, greater trochanter 16, intertrochanteric crest 17, neck of femur 18, head of femur 19, posteroinferior iliac spine. 3.1 Plain radiograph of the hip and pelvis (anteroposterior view). Distance of 3 to 5 cm is considered normal.

Neutral alignment of the hip and pelvis is confirmed by measuring the distance from the sacrococcygeal junction to the superior symphysis pubis. Important landmarks are as follow: iliopectineal line, ilioischial line of Kohler, Shenton’s line, sourcil, teardrop sign, and acetabular floor. Alignment is evaluated by visualization of symmetry. Specialized views: frog-leg lateral, anterior and posterior oblique (Judet’s views), false profile, Ferguson’s view (pelvic outlet), and the pelvic inlet view. Routine: anteroposterior (AP) and lateral views.

Normal hip xray male