Since September 1964, neonates born in New Plymouth have undergone clinical examination for Neonatal Instability of the Hip (NIH) in a structured clinical screening programme. Forty one thousand, five hundred and sixty three babies were born during the period of this study, of which 1,638 were diagnosed as having unstable hips. Six hundred and thirty three with persisting instability were splinted (1.6%), with five hips failing splintage. In addition, three unsplinted hips progressed to CDH, and there were four late-presenting (walking) cases of CDH, giving an overall failure rate for the programme of 0.29 per 1000 live births, with a late-presenting (walking) CDH incidence of 0.1 per 1000 live births. This study confirms that clinical screening for NIH by experienced orthopaedic examiners significantly lowers the incidence of late-presenting (walking) CDH.

Purpose

There is concern that the positive predictive value (PPV) of neonatal screening for instability may have deteriorated over recent years, this study aims to evaluate this.

The purpose of this study was to audit screening and treatment programmes for Developmental Dysplasia of the Hip (DDH) over a 12-year period from 1989 to 2000 with respect to late presentation and treatment rate and duration.

All babies born in Queen Mary Hospital are clinically screened for DDH by a consultant orthopaedic surgeon. Unstable hips are treated by Pavlik Harness and attend an ultrasound clinic run by an orthopaedic surgeon within 2 weeks. High-risk babies or those with suspected instability can also be referred for ultrasound. Serial ultrasound exams assisted with determining the duration of splintage. Radiographs are taken at 4 to 6 months. Late presenters were identified and analysed.

Over the 12-year period 13 cases of late presenting DDH were identified (0.6 per 1000). Half of these had not been screened. None had ultrasound screening. Our treatment rate was approximately 4 per 1000 live births.

Our screening programme can be improved by increased capture of patients for clinical screening. Ultrasound is a useful tool in managing neonatal hip instability allowing duration of splintage to be tailored to the individual and allows early detection of treatment failure.

The incidence of DDH Varies depending on genetic and ethnic varieties but in Ireland on an average in 3 per 1,000 live births. Current treatment is focused on early diagnosis and congruent reduction of the hip joint. With conservative measures, principally skilful use of the Pavlik harness, the majority of (85%) of dislocated or subluxated hips will be successfully treated. Late diagnosis impacts on the mode of treatment and on the subsequent outcome.

An audit of annual incidence of DDH in North Eastern health board, in Ireland showed a dramatic increase in late diagnosis (> 4 month). There were 4668 live births in 2004 with 17 cases of DDH presenting between the ages of 4 – 36 months during this period. The mean age of presentation was 10 months. Two cases were bilateral. The male: female ratio was 4.6:1. Risk factor analysis showed, only 50% fell in to the high risk group, majority of them had positive family history. Three fourth of them were frank dislocations and all of them required operative intervention. As opposed to early presenters, only 10% needed operative intervention. 30% of the late presenters needed major osteotomies.

We examined the reasons for this extreme high rate of late presenters and argue for the introduction of routine ultrasound screening in this region based on historical high incidence of DDH and the dramatic incidence of delayed diagnosis.