Overview Introduction Normal Development of the Hip Etiology and Pathoanatomy Epidemiology and Diagnosis Ultrasound morphologic and dynamic
Introduction Developmental Dysplasia of the Hip • DDH - preferred term • Teratogenic hips • Subluxation • Dislocation-usually posterosuperior (reducible vs irreducible) • Dysplasia
Background Risk Factors • 1/1,000 born with dislocated hip • 10/10,000 born with subluxation or dysplasia • 80% Female • First born children • Family history (6% one affected child, 12% one affected parent, 36% one child + one parent) • Oligohydramnios • Breech (sustained hamstring forces) • Native Americans (swaddling cultures) • Left 60% (left occiput ant), Right 20%, both 20% • Torticollis or LE deformity
Diagnosis Newborn screening • Ortolani’s and Barlow’s maneuvers with a thorough history and physical • Warm, quiet environment with removal of diaper • Head to toe exam to detect any associated conditons (Torticollis, Ligamentous Laxity etc.) • Baseline Neuro and Spine Exam
IMAGING STUDIES (ULTRASOUND) BASELINE: line of ilium which intersects the bony and the cartilaginous portions of the acetabulum.15-29 As the femoral head subluxates: decreased ALPHA angle increased BETA angle
IMAGING STUDIES (ULTRASOUND)The Ultrasound ( before 3 mo. ) Ilium Abductor M.
Diagnosis Some cases still missed At risk groups should be further screened AAP • Recs further imaging (e.g. US) if exam is “inconclusive” AND First degree relative + female Breech Positive provocative maneuver (Ortolani or Barlow) • Referral to Orthopaedist
Imaging X-rays • Femoral head ossification center 4 -7 months Ultrasound • Operator dependent CT MRI Arthrograms • Open vs closed reduction
Imaging Ultrasound • Introduced in 1978 for eval of DDH • Operator dependent • Useful in confirming subluxation, identifying dysplasia of cartilaginous acetabulum, documenting reducibility • Prox Femoral Ossification Center interferes • Requires a window in spica cast (avoid)
UltrasoundGraf’s alphaangle>60° = normal*line w/ iliumbisects head 50/50
Fig. 5-A:: Figs. 5-A, 5-B, and 5-C: Ultrasonography of the infant hip with use of thedynamic technique. (Figures kindly provided by Prof. H. T. Harcke.)Fig. 5-A: Photograph showing the position of the transducer used to obtain thetransverse flexion view. With the hip in this position of flexion and adduction, a posteriorpush is analogous to the Barlow test.
Fig. 5-B:: A transverse flexion ultrasonographic view of a normal hip showsthe femoral head (F) remaining in contact with the ischium (arrows) duringmovement. A = anterior, L = lateral, and P = posterior.
Fig. 5-C:: With instability and displacement, the femoral head moves laterallyand posteriorly. The laterally displaced head (F, open arrows) has no contactwith the ischium (solid arrows). Fibrofatty tissue (T) with increased echogenicityfills the acetabulum. A = anterior, L = lateral, and P = posterior.