IS THERE A DIFFERENCE BETWEEN THE EPIDEMIOLOGIC CHARACTERISTICS OF HIP DISLOCATION DIAGNOSED EARLY AND LATE

OBJECTIVE: To determine if there are epidemiologic differences between patients with early and late developmental dislocation of the hip (DD H). DESIGN: A chart review. SETTING: A university-affiliate children's hospital. PATIENTS: Two hundred and forty-three children, 191 with ea rly DDH and 52 with late DDH. MAIN OUTCOME MEASURES: Sex, side involve d and prevalence of bilaterality. RESULTS: There were significant diff erences between the two groups with respect to side involved (p < 0.00 02) and bilaterality (p = 0.006) but not in relation to sex. Left-side d dislocations were predominant in the early group and right-sided dis locations in the late group. Bilaterality was more common in the late group. CONCLUSION: There is circumstantial epidemiologic evidence that late DDH may be a different entity from early DDH.