The incidence of clinically significant avascular necrosis (AVN) following medial open reduction of the dislocated hip in children with developmental dysplasia of the hip (DDH) remains unknown. We performed a systematic review of the literature to identify all clinical studies reporting the results of medial open reduction surgery. A total of 14 papers reporting 734 hips met the inclusion criteria. The mean follow-up was 10.9 years (2 to 28). The rate of clinically significant AVN (types 2 to 4) was 20% (149/734). From these papers 221 hips in 174 children had sufficient information to permit more detailed analysis. The rate of AVN increased with the length of follow-up to 24% at skeletal maturity, with type 2 AVN predominating in hips after five years’ follow-up. The presence of AVN resulted in a higher incidence of an unsatisfactory outcome at skeletal maturity (55% vs 20% in hips with no AVN; p < 0.001). A higher rate of AVN was identified when surgery was performed in children aged < 12 months, and when hips were immobilised in ≥ 60°of abduction post-operatively. Multivariate analysis showed that younger age at operation, need for further surgery and post-operative hip abduction of ≥ 60° increased the risk of the development of clinically significant AVN.

Cite this article: Bone Joint J 2014;96-B:279–86.

We present our early experience of arthroscopic reduction of the dislocated hip in very young infants with developmental dysplasia of the hip (DDH).

Eight dislocated hips, which had failed attempts at closed reduction, were treated by arthroscopy of the hip in five children with a mean age of 5.8 months (4 to 7). A two-portal technique was used, with a medial sub-adductor portal for a 2.7 mm cannulated system with a 70° arthroscope and an anterolateral portal for the instruments. Following evaluation of the key intra-articular structures, the hypertrophic ligamentum teres and acetabular pulvinar were resected, and a limited release of the capsule was performed prior to reduction of the hip. All hips were reduced by a single arthroscopic procedure, the reduction being confirmed on MRI scan. None of the hips had an inverted labrum. The greatest obstacle to reduction was a constriction of the capsule. At a mean follow-up of 13.2 months (9 to 24), all eight hips remained stable. Three developed avascular necrosis. The mean acetabular index decreased from 35.5° (30° to 40°) pre-operatively to 23.3° (17° to 28°).

This study demonstrates that arthroscopic reduction is feasible using two standardised portals. Longer follow-up studies are necessary to evaluate the functional results.

The association between idiopathic congenital talipes equinovarus (CTEV) and developmental dysplasia of the hip is uncertain. We present an observational cohort study spanning 6.5 years of selective ultrasound screening of hips in clubfoot. From 119 babies with CTEV there were nine cases of hip dysplasia, in seven individuals. This suggests that 1 in 17 babies with CTEV will have underlying hip dysplasia.

This study supports selective ultrasound screening of hips in infants with CTEV.

We describe a near-fatal event, probably due to air embolism, following an air arthrogram for developmental hip dysplasia in a baby aged four months. The sequence of events and the subsequent treatment are described. There is little information about this complication in the literature. The presumed mechanism and alternative methods for confirmation of placement of the needle are discussed. We no longer use air arthrography in children.

This prospective cohort study aimed to investigate the relationship between developmental dysplasia of the hip and mode of delivery in 571 consecutive breech infants using a modified Graf’s static morphological method to grade the severity of dysplasia.

In this group, 262 infants were born by planned Caesarian section, 223 by emergency section and 86 vaginally. Taking all grades of hip dysplasia into account (Graf types II, III and IV), there was no statistical difference in the incidence of dysplasia between the groups (elective section 8.4%, emergency section 8.1% and vaginal delivery 7.0%). However, when cases with Graf type II dysplasia, which may represent physiological immaturity, were excluded, the rate of type III and IV hips, which we consider to be clinically relevant, increased in the vaginally delivered group (4.7%) compared with the elective section group (1.1%), with a relative risk of approximately 1:4 (95% confidence interval 1.03 to 15.91). No difference was observed between the emergency and elective section groups, or between the emergency section and vaginally delivered groups.

This study supports previous published work, with the added value that the diagnoses were all confirmed by ultrasound.

The Salter innominate osteotomy has been used successfully for many years in the treatment of developmental dysplasia of the hip. One of its main drawbacks is the need for internal fixation with pins and their subsequent removal. We describe a modification of this osteotomy that does not require pin fixation and secondary removal. We retrospectively reviewed 114 hips in 94 patients who had been operated on by a single surgeon. An oblique rather than the original horizontal osteotomy was used without internal fixation. There were 80 female and 14 male patients. The mean age at operation was 25 months (18 to 84) and the mean follow-up was 30 months (12 to 88). Most patients required additional open reduction and capsuloplasty. The mean pre-operative acetabular index was 37.9° (24° to 54°), which decreased to 19.9° (7° to 29°) in the immediate post-operative period, and improved to 14.6° (5° to 25°) at the final follow-up (student’s t-test, p < 0.0001).

We believe that by changing the direction of the osteotomy line, it is possible to avoid pin fixation. The radiological outcomes are comparable to those of the original technique, but longer follow-up will be necessary.

Of the 34 723 infants born between 1 June 1992 and 31 May 2002, the hips of 2578 with clinical instability or at-risk factors for developmental dysplasia of the hip were imaged by ultrasound.

Instability of the hip was present in 77 patients, of whom only 24 (31.2%) had an associated risk factor. From the ‘at-risk’ groups, the overall risk of type-III dysplasia, instability and irreducibility was 1:15 when family history, 1:27 when breech delivery and 1:33 when foot deformity were considered as risk factors. Of those hips which were ultrasonographically stable, 88 had type-III dysplasia.

A national programme of selective ultrasound screening of at-risk factors for the diagnosis of hip dislocation or instability alone cannot be recommended because of its low predictive value (1:88). However, the incidence of type-III dysplasia and hip dislocation or dislocatability in the groups with clinical instability, family history, breech position and possibly postural foot deformity as risk factors could justify a programme of selective ultrasound imaging.