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A fundamental of patient safety is to avoid unnecessary operations. It's well recognized with developmental dysplasia of the hip (DDH) that early detection will mostly result in successful conservative treatment and avoid surgery.  

As an example we looked at the infants in Northern Ireland, who had dislocated or unstable hips. Of the infants we treated before 10 days of age 96% had satisfactory reduction and required no further intervention by just using a simple Pavlik harness. Of the children seen between 10 and 39 days of age, 85% responded to treatment with splintage, but 15% did go on to require surgery. When it came to those a little bit older, between 40 and 63 days of age, the success rate decreased to 74%. In the children between 64 days and six months, only 60% responded to splintage alone. Diagnosis after that age generally requires surgical treatment. 

To detect these hips at an early age different policies are employed. Some countries, such as Austria, Germany, Sweden, Slovenia, and more recently Mongolia, use universal screening with hip ultrasound examination. In these countries, the vast majority are diagnosed early with good conservative results. Other countries, such as UK and Ireland use clinical screening and selective ultrasound scans, those infants with a risk factor such as a breech delivery or a strong family history are scanned, as well as those where hip instability is detected on the physical baby checks.  

The history of selective screening goes back many decades, however, a very wide range of results are reported. One of the earlier studies from Malmo in Sweden, achieved very good results, with late presentation of dislocated hips of just 0.1 per thousand births, that was taking a strict definition of late as being after 14 days of age. These good results may have been because a very small number of expert examiners examined the babies. On the other hand, a recent paper form Great Britain reported a late rate of dislocation of 1.28 per thousand births and this used the much narrower diagnostic criteria of late as being of over one year of age. In Northern Ireland we have a similar policy to the rest of the United Kingdom, using the same criteria of one year of age, our late diagnosis rate was 0.3 per thousand of live-births. This shows that despite having the same policy, very different results can be achieved in practice. 

So, why did our results differ from those in Great Britain? We were concerned about delays some babies encountered in accessing services. In 2010, we had 160 patients who were diagnosed after three months of age. To monitor our performance we initiated prospective data collection on all our patients treated for DDH, this allowed us to identify delays. One of the main bottlenecks was the lack of ultrasound scanning capacity with children waiting for scans and many ultimately having x-rays as they became too old for ultrasound, and thereby potentially missed the opportunity for conservative treatment. There were also administrative delays in referrals getting through to us. So we successfully campaigned for increased ultrasound capacity. Because we've been doing more ultrasound scans, we're doing a lot less x-rays. In the province the number of ultrasound scans increase from around 5,000 to 6,000 per year, however the number of x-rays in infants has disproportionally reduced from 8,000 to 2,000. This may reflect the increased confidence in the screening service from our colleagues in general practice and paediatrics. We also use the opportunity to feedback to referrers to ensure the most appropriate patients are seen.  

This has been effective the number of infants diagnosed with DDH after three months has dropped from 160 to around 35 per year. However, we still see about 4 or 5 patients per year who are diagnosed beyond the age of one year. This number has remained fairly constant, these are patients without risk factors and who were not referred on clinical examination. This is a group of patients who we cannot reliably reach using selective screening, to eliminate these late presentations we would need to move to a universal screening program.  

We have reduced the number of surgeries for DDH from an average of 75 per year, to around 30. Although most patients who have surgery do very well, there is a proportion who have sub-optimal outcomes due to growth disturbance and residual dysplasia.  

A particular metric we found useful is the number of closed reductions, closed reductions are generally done before walking age, and often they present because of clinical abnormalities that are picked up on the statutory examinations at birth, six weeks or four months. With any delay they can easily lose the opportunity to respond to splintage. The number of closed reductions has reduced from 40 a year down to an average of 6 a year.  

To measure is to know, so if there is a screening program, the performance has to be quantified. The important factors are; treatment rates, late diagnosis rates, surgical treatment rates with particular attention to the number of closed reductions. Selective screening will not detect all pathology so there will remain a residual number of  children with a late diagnosis. There is a separate argument about moving to universal from selective ultrasound screening but irrespective of the adopted policy it must be audited to ensure it is as effective as possible and protect children from potentially poor outcome.  

H. Düppe, L. G. Danielsson  Screening of neonatal instability and of developmental dislocation of the hip. A survey of 132 601 living newborn infants between 1956 and 1999 J Bone Joint Surg [Br] 2002;84-B:878-85

Broadhurst C, Rhodes AML, Harper P, et al. What is the incidence of late detection of developmental dysplasia of the hip in England?: a 26-year national study of children diagnosed after the age of one. Bone Joint J. 2019;101-B(3):281–287 

Milligan DJ, Cosgrove AP. Monitoring of a hip surveillance programme protects infants from radiation and surgical intervention. Bone Joint J. 2020 Apr;102-B(4):495-500 

Thallinger C, Pospischill R, Ganger R, et al. Long-term results of a nationwide general ultrasound screening system for developmental disorders of the hip: the Austrian hip screening program. J Child Orthop. 2014;8(1):3–10. 

Cosgrove AP, Maizen C. Detection and treatment of developmental dysplasia of the hip in infants: updates and recommendations. Curr Opin Pediatr. 2025 Feb 1;37(1):88-93. doi: 10.1097/MOP.0000000000001420. Epub 2024 Nov 28. PMID: 39699106.