The stability of the hip joint relies upon the following structures: In very severe cases the ball can come out of the socket (dislocate). Ultimately there is a mismatch in the fit of the ball into the hip socket, meaning that the femoral head is not held tightly in place and therefore increased movement (shearing) occurs. It is a condition where the hip joint has not developed properly and this can affect the shape of the bones, the orientation of the ball or socket, or all the above. The earlier the closure, the greater the eventual deformity.Developmental Dysplasia of the hip (DDH) is an umbrella term used to describe various bony abnormalities which result in poor containment of the ball of the hip (femoral head) within the hip socket (acetabulum). Leads to premature triradiate cartilage closure. May detect narrowing of triradiate space.

type IV pelvic ring with instability and > 2 cm pelvic ring displacementīlow to pubis/ischial ramus/proximal femur leads to injury at interface of 2 superior arms of triradiate cartilage and metaphyses of ilium.Ī triangular medial metaphyseal fragment (Thurston-Holland fragment) is often seen in SH II injuries.ĭifficult to see on initial radiographs.

type III pelvic ring with displaced acetabular fractures > 2mm.

type II iliac wing fractures with > 2-3 cm displacement.

obturator oblique = open obturator foramen.

iliac oblique = visualization of iliac wing.

obturator oblique = posterior wall + anterior column.

iliac oblique = anterior wall + posterior column.

obturator oblique = semi-lateral 45° on contralateral side.

iliac oblique = semi-lateral 45° on ipsilateral side.

superimposition of pubic symphysis + S2 body.

vertical displacement + flexion/extension of hemipelvis.

til 20-35° cephalad if male, 30-45° cephalad if female.

equal distance between greater trochanters + sacrum.

measurement of horizontal/bi-ischial diameter.

assess relationship of femoral head + acetabulum.

pelvis tilted anteriorly 45° + hips abducted.

superimposition of posterior ischium/ilium.

no superimposition of femurs + pubic arch.

if lesser trochanters are visible, they should be of symmetrical size and shape.

too much external rotation of leg leads to increased visualization of lesser trochanter.

symmetrical greater trochanters + obturator foramen.

coccyx located 2cm above pubic symphysis.

posterior ¼ = lower ½ of sciatic buttress to roof of greater sciatic notch.

anterior ¾ = pelvic brim, pubic symphysis to ilioischial line.

iliopectineal line (6) = anterior column.

always superimposed on teardrop = disruption 2/2 rotation vs.

pelvic brim + quadrilateral surface + posterior obturator foramen + ischiopubic ramus.

ilioischial line (5) = posterior column.

internal + external limbs = not in same coronal plane but usually parallel + forms U.

internal/medial limb = outer wall of obturator canal + quadrilateral surface.

lower border = ischiopubic/acetabular notch + superior obturator foramen.

external/lateral limb = inferior anterior acetabular wall + outer cotyloid fossa.

teardrop (4) = anterior/posterior column.

acetabular roof = superior weight-bearing portion.sourcil (3) = anterior/posterior column.inferior margin of superior pubic ramus.

anterior rim (2) = anterior wall/column.

posterior rim (1) = posterior wall/column.

aim midway between ASIS + pubic symphysis.

Myelodysplasia (myelomeningocele, spinal bifida)ĭysplasia Epiphysealis Hemimelica (Trevor's Disease) Obstetric Brachial Plexopathy (Erb's, Klumpke's Palsy)Īnterolateral Bowing & Congenital Pseudoarthrosis of TibiaĬerebral Palsy - Upper Extremity Disorders

Proximal Tibia Metaphyseal FX - PediatricĬhronic Recurrent Multifocal Osteomyelitis (CRMO) Pediatric Ankle Trauma Radiographic Evaluationĭistal Humerus Physeal Separation - Pediatric Pediatric Knee Trauma Radiographic Evaluation Pediatric Hip Trauma Radiographic Evaluation Pediatric Pelvis Trauma Radiographic Evaluation

Normal hip xray teen