Can Medialization of Acetabular Rim Be a Prognostic Factor in Treatment of Developmental Dysplasia of Hip?

OBJECTIVES

To investigate if acetabular rim medialization (ARM) can be used as a new parameter in determining the treatment choice and duration in Graf type III and IV hips.

METHODS

Among the 12,300 infants who underwent hip ultrasound (US) according to Graf's method between 2015 and 2019, 26 infants (9 had bilateral pathology hence 35 hips) with type III and IV hips, whose follow-up data could be obtained were included in the study. Age of the infants at the initial diagnosis, ARM measurement, the duration of harness treatment, and the treatment results were noted. To determine the extent of ARM, distance between a line that is drawn tangential to the iliac wing and acetabular rim was measured.

RESULTS

In cases with poor prognosis, ARM measurement was 6 to 8.5 mm on the right hip and 4 to 9 mm on the left hip. Bilaterality or unilaterality, left or right pathology, and gender did not have a significant effect on the prognosis (P >.05). Age at the initial diagnosis and ARM had significant effects on treatment success (P = .04, P = .00, respectively). In predicting the prognosis, ARM was found to be more successful than age (AUC = 0.95 versus AUC = 0.68). When these two variables were evaluated together, the success in predicting the prognosis significantly increased (AUC = 0.98).

CONCLUSIONS

ARM measurement may have an important role in determining the treatment method and duration in Graf type III and IV hips. It can be used as a prognostic factor alone or in combination with treatment initiation time. When the two factors are combined, prognostic value significantly increases.