Aims The aim of this study was to establish the incidence of developmental dysplasia of the hip (DDH) diagnosed after one-year of age in England, stratified by age, gender, year, and region of diagnosis. Patients and Methods A descriptive observational study was performed by linking primary and secondary care information from two independent national databases of routinely collected data: the United Kingdom Clinical Practice Research Datalink and Hospital Episode Statistics. The study examined all children from 1 January 1990 to 1 January 2016 who had a new first diagnostic code for DDH aged between one and eight years old. Results The incidence of late-diagnosed DDH was 1.28 per 1000 live births. Within the study population, 754 children were identified with a diagnosis of DDH after one-year of age. Of all late diagnoses, 536 (71.1%) were detected between one to two years of age. There were 608 female patients (80.6%) and 146 male patients (19.4%), giving a female-to-male ratio of 4.2:1. Distribution was evenly spread throughout England. Conclusion The incidence of late-diagnosed DDH has not been reduced from that reported 35 years ago, prior to the introduction of the national selective screening programme for DDH. Cite this article: Bone Joint J 2019;101-B:281–287.

Background:Infants with dislocated irreducible (D/I) hips can be substantially harder to treat than infants with dislocated but reducible hips. The purpose of this study was to compare treatment methods and outcomes for infants with D/I hips in order to optimize management of this difficult patient cohort.Methods:A multicenter prospective hip dysplasia study database was analyzed from 2010 to 2016. Infants aged below 6 months with clinically and radiologically confirmed D/I hips were included in the study. Teratological hips (syndromic/neuromuscular) were excluded.Results:In total, 59 hips in 52 patients were included. All hips were clinically Ortolani negative and radiologically dislocated but irreducible on presentation and had at least 20 months of follow-up. Mean age at diagnosis was 1.9 months (range, 0.1 to 5.9 mo). There were 33 left hips, 12 right hips, and 14 bilateral hips (7 patients). In total, 48 of 59 hips were treated in Pavlik harness. The remainder were treated by alternative braces or primary closed or open reductions. Pavlik treatment was successful in 27 of 48 hips. Pavlik treatment was abandoned in 21 D/I hips, 3 due to femoral nerve palsy and the remainder due to failure to achieve reduction. There was no statistical correlation between Pavlik success and age at diagnosis (P=0.22), patient sex (P=0.61), or bilateral compared with unilateral D/I hips (P=0.07). Left hips were more likely to be successfully reduced in Pavlik harness than right hips (P=0.01). Five complications occurred: 3 patients developed femoral nerve palsy in Pavlik harness, while 2 patients developed avascular necrosis, both after failed Pavlik treatment and subsequent surgery.Conclusions:Pavlik harness treatment has been demonstrated to be a safe and sensible first-line treatment for infants with D/I hips. Left hips were more likely to be successfully reduced in Pavlik harness than right hips, but age, sex, and bilaterality were not correlated. The outcomes demonstrated from this multicentre prospective database inform management of this complex patient cohort.Level of Evidence:Level II—prognostic study: less-quality prospective study.

Previous in vitro work demonstrated porous PLA and PLGA both had the mechanical strength and sustained the excellent skeletal stem cell (SSC) growth required of an osteogenic bonegraft substitute, for use in impaction bone grafting. The purpose of this investigation was to assess the effects of the addition of hydroxyapatite (HA) to the scaffolds before clinical translation. PLA, PLA+10% HA, PLGA, and PLGA+10% HA were milled and impacted into discs before undergoing a standardized shear test. Cellular compatibility analysis followed 14 days incubation with human skeletal stems cells (SSC). The best two performing polymers were taken forward for in vivo analysis. SSC seeded polymer discs were implanted subcutaneously in mice. All polymers had superior mechanical shear strength compared with allograft (p < 0.01). Excellent SSC survival was demonstrated on all polymers, but the PLA polymers showed enhanced osteoblastic activity (ALP assay p < 0.01) and collagen-1 formation. In vivo analysis was performed on PLA and PLA+10% HA. MicroCT analysis revealed increased bone formation on the PLA HA (p < 0.01), and excellent neo-vessel formation in both samples. Histology confirmed evidence of de novo bone formation. PLA HA showed both enhanced osteoinductive and osteogenic capacity. This polymer composite has been selected for scaled-up experimentation before clinical translation.

Purpose This prospective study was undertaken to describe patterns of fragmentation of the femoral epiphysis following a proximal femoral varus osteotomy (PFVO) done during stage I of LCPD and to assess the disease duration and outcome in each pattern. Methods A total of 25 children treated by a PFVO in stage I of LCPD were followed until healing. The MRI Perfusion Index, radiographic changes in the femoral epiphysis, disease duration and the Sphericity Deviation Score (SDS) at healing were documented. The reproducibility of classification of the pattern of fragmentation, estimation of disease duration and SDS were assessed. The duration of the disease and SDS in the patterns of fragmentation were compared. Results Four patterns of fragmentation were noted, namely, typical fragmentation, bypassing fragmentation, abortive fragmentation and atypical fragmentation with horizontal fissuring. The reproducibility of classifying the pattern of fragmentation was moderate (Kappa: 0.48) while the reproducibility of other continuous variables was excellent. The Perfusion Index was less than 50% in every affected hip. The duration of the disease and SDS were lowest in children in whom the stage of fragmentation was bypassed but these differences were not statistically significant. Conclusion Following a proximal femoral osteotomy during stage I of LCPD the fragmentation stage may be bypassed partially or completely and the chances of a good outcome appear to be very good if fragmentation is bypassed. Level of Evidence Level II Prognostic Study