Imaging in the Surgical Management of Developmental Dislocation of the Hip

Abstract

Although the use of ultrasound in the diagnosis and early treatment of developmental dysplasia of the hip (DDH) has reduced the number of patients diagnosed late and decreased the number of operative procedures, surgical treatment is still needed in some patients. Late cases continue to occur as a result of missing the screening examination, being normal at initial screening and missing followup. Dysplasia may persist despite appropriate nonoperative or operative treatment. Many of these patients subsequently undergo closed or open reduction and femoral or acetabular reconstruction. Ultrasound of the hips is generally used up to 6 or 8 months of age, during which time the hips are largely cartilaginous, and radiographs after that time when bony development is more complete. Options to supplement ultrasound and radiography include arthrography, computed tomography, and magnetic resonance imaging. Several advances have been made in the imaging of DDH and its complications including acetabular labral pathology and of femoroacetabular impingement (FAI). We review imaging techniques other than ultrasound used in the management of DDH.

Developmental dysplasia of the hip: What has changed in the last 20 years?

“…Computed tomography (CT) is useful for assessment of quality of reduction after closed or open reduction and fixation in a spica cast [51] . It is also useful in the treatment of adolescents and young adults, defining the dysplasia and allowing for better selection of the appropriate procedures, including pelvic and/or femoral osteotomies [52] . Although ionizing radiation exposure from a limited CT is low, magnetic resonance imaging (MRI) has been effectively used completely avoiding radiation exposure (Figure 1).…”

“…MRI is also useful in the assessment of labral abnormalities. Isolated labral tears are best treated with arthroscopic techniques [52] . Arthrography displays the cartilaginous anatomy of the femoral head and the acetabulum.…”

The layer concept: utilization in determining the pain generators, pathology and how structure determines treatment

“…These studies provide structural blueprints for determining alpha angles, beta angles and McKibbon indices [12]. dGEM-RIC studies can be used, when indicated, to determine the health of the cartilage [9].…”

Utility of magnetic resonance imaging (MRI) after closed reduction of developmental dysplasia of the hip

“…Neither radiography nor CT adequately images the cartilaginous femoral head, and its position must be extrapolated from that of the proximal femoral metaphysis [2,8]. Even if the femoral head is partially ossified, its position cannot be assumed to be central.…”

“…In conservative treatment, arthrography was proposed but requires general anaesthesia [2]. Other alternative techniques such as ultrasonography remain of poor reliability [2]. Magnetic resonance imaging (MRI) has already been used in the determination of the adequacy of the surgical reduction of the dislocation of an immature hip [9][10][11][12][13].…”