Open reduction is required following failed conservative treatment
of developmental dysplasia of the hip (DDH). The Ludloff medial
approach is commonly used, but poor results have been reported,
with rates of the development of avascular necrosis (AVN) varying
between 8% and 54%. This retrospective cohort study evaluates the
long-term radiographic and clinical outcome of dislocated hips treated
using this approach. Children with a dislocated hip, younger than one year of age
at the time of surgery, who were treated using a medial approach
were eligible for the study. Radiographs were evaluated for the
degree of dislocation and the presence of an ossific nucleus preoperatively,
and for the degree of AVN and residual dysplasia at one and five
years and at a mean of 12.7 years (4.6 to 20.8) postoperatively.
Radiographic outcome was assessed using the Severin classification,
after five years of age. Further surgical procedures were recorded.
Functional outcome was assessed using the Pediatric Outcomes Data
Collection Instrument (PODCI) or the Hip Disability and Osteoarthritis
Outcome Score (HOOS), depending on the patient’s age.Aims
Patients and Methods
In this prospective study of 18 hips we compared the efficacy of ultrasound with CT in determining the position of the femoral head in a spica cast after closed or open reduction in children with developmental dysplasia of the hip. Ultrasound was performed through the perineal opening of the cast. With a transinguinal approach, the superior ramus of the pubis, the acetabulum, the femoral head and the femoral neck can be depicted in one plane. The CT and ultrasound images were blinded and reviewed by two of the authors. Ultrasound was inconclusive in the first two reductions since the perineal opening was too small to see all the landmarks in one plane. In the following 16 reductions the landmarks were well defined and interpretation of the CT and ultrasound was similar. The perineal opening in the spica cast should be made in such a way that the ultrasound probe can be positioned in the groin so that the landmarks can be shown in one plane.
