Decline in the incidence of late diagnosed congenital dislocation of the hip.

INTRODUCTION

We reviewed the incidence of early and late diagnosed CDH over a 13 yr period in a single maternity with a well established follow-up program and a stable population base. In March 1991, all newborn infants were nursed in the lateral or supine position, having previously been nursed prone. In addition, a dedicated hip screener was appointed in October 1992. We wished to determine whether these changes could have led to a reduction in late diagnosed CDH.

METHODS

Babies with suspected CDH were seen by a single consultant orthopaedic surgeon within 1 week of birth. Splints were not applied until diagnosis was confirmed by the orthopaedic surgeon. The study period was from January 1983 to December 1995, inclusive.

RESULTS

37,383 babies were born during the study period, an average of 2,876 births per annum. The average rate of babies referred to the orthopaedic surgeon was 12.8 per 1,000 (range 5.5-28.2 per 1,000). The average incidence of babies splinted early was 7.19 per 1,000 (range 4.0-14.1 per 1,000) with no discernible increase or decrease over the yrs. In contrast, there was a clear reduction in the incidence of late diagnosed CDH; 42/24,713 births (January 1983-February 1992) compared to only 2/12,673 births (March 1992-December 1995; p < 0.0001. Twelve of the 44 infants (27 per cent) diagnosed with late diagnosed CDH were discovered by the policy of routine hip radiographs at 6 months of age of all babies born by breech presentation (2/12) or those with a positive family history of CDH in a first degree relative (10/12). Six others had a diagnosis of CDH confirmed by X-rays done at 6 months of age because of doubts about their examination in the newborn period.

CONCLUSIONS

Nursing infants in the supine or lateral position and the introduction of a single hip screener were associated with a reduction in the incidence of late diagnosed CDH. Routine hip radiographs of high risk infants at 6 months of age proved to be a valuable safety net in detecting a significant proportion of previously undetected infants with CDH.