[Sonographic screening of the newborn hip at the university hospital Marburg--a long-run analysis].

BACKGROUND

Since 1985 the hips of the newborns have been sonographically screened at the University Hospital Marburg by staff of the Orthopaedic Department. This study was conducted to collect data on the local incidence of DDH (developmental dysplasia of the hip). Moreover, the diagnostic findings were checked critically to detect weak points. Another aim was to analyse the influence of investigators' experience on the treatment recommendation.

MATERIAL AND METHODS

In a retrospective study, 18 247 hip sonograms in a treatment period from 1985 to 2009 were analysed. The following parameters were evaluated: perinatal incidents (e.g., breech presentation, Caesarean section, premature delivery), orthopaedic findings (e.g., club foot, limitation of hip abduction). Bony roof, superior bony rim and cartilaginous roof were analysed; α- and β-angles and hip type according to Graf were documented. Comparisons between variables were calculated by means of adequate statistic tests. χ(2)-values and coefficients of correlation were used to detect significance.

RESULTS

All in all 55 physicians of our Orthopaedic Department conducted 350 measurements on average (min. 1; max. 1993). Accuracy of documentation improved over time. In particular in the beginning of the screening, the hip angles according to Graf were not completely determined and sonograms were classified by "visual diagnosis". The β-angle was not measured at the outset. In the course of time we measured a decrease of the diagnosis hip type II a according to Graf. In the years 1985-1989 more than 40 % of the hips were described as physiologically immature. We evaluated a numerical regression of hip type II a to 16 % in time period 1990-1994 and 9 % in time period 2005-2009. There was a significant correlation between breech presentation and decentering and eccentric hips. Inexperienced physicians recommend more often therapeutic interventions (p ≤ 0.01). Treatment of hip type II a according to Graf was inconsistent over time.

CONCLUSION

This study demonstrates the necessity of standardised hip sonography. Treatment according to measured hip type should be concise. Training programmes both for instructors and medical assistant staff is mandatory. "Bedside teaching" is not constructive.