Acetabular morphology and orientation differs from ethnic group to another. Thus, investigating the natural history of the parameters that are used to assess both was a matter of essence. Nevertheless, clarification the picture of normal value in our society was the main aim of this study. However, Acetabular head index (AHI) and center edge angle (CEA) were the most sensitive indicative parameters for acetabular dysplasia. Hence, they were the main variables used in evaluation of acetabular development. A cross-sectional retrospective study that had been done in a tertiary center. Computed tomography abdomen scouts’ radiographs of non-orthopedics patients were included. They had no history of pelvic or hips’ related symptoms or fractures in femur or pelvis. Images’ reports were reviewed to exclude those with tumors in the femur or pelvic bones. A total of 81 patients was included with 51% of them were males. The mean of age was 10.38± 3.96. CEA was measured using Wiberg technique, means of CEA were 33.71±6.53 and 36.50±7.39 for males and females, respectively. Nonetheless, AHI means were 83.81±6.10 and 84.66±4.17 for males and females, respectively. On the other hand, CEA was increasing by a factor 0.26 for each year (3-18, range). In addition, positive significant correlation was detected between CEA and age as found by linear regression r 2 0.460 (f(df1,79) =21.232, P ≤0.0001). Also, Body mass index (BMI) was positively correlated with CEA r 0.410, P 0.004). This study shows that obesity and aging are linked to increased CEA. Each ethnic group has its own normal values that must be studied to avoid premature diagnosis

This investigation examined the validity of the hypothesis that the acetabulum in congenital dislocation of the hip will develop satisfactorily provided accurate congruous and concentric reduction is obtained as early as possible, and is maintained throughout growth. Seventy-two patients with eighty-five hips were studied. The children were more than one year old on admission and over ten years at the time of review. Acetabular development was assessed radiologically by measurement of the acetabular angle. Angles of less than 21 degrees were regarded as normal, and more than 21 degrees as indicating some failure of development. Satisfactory acetabular development occurred in 80 per cent (angles 24 degrees or below), and was unsatisfactory in 20 per cent (angles above 24 degrees). If three errors in management, namely failure to obtain congruity, failure to maintain congruity and ischaemic necrosis secondary to manipulative reductions, are excluded from the analysis, it is found that 95 per cent of acetabula develop satisfactorily. The outcome is largely independent of the age on admission up to four years old, and of bilateral involvement. It is concluded that acetabuloplasty should not be necessary if the patient is admitted under the age of four or congruity is obtained in the functional position under four and a half years

We reviewed the serial radiographs of 54 hips in 47 children treated by closed reduction for congenital dislocation of the hip and followed to at least 14 years of age, to determine the causes of acetabular dysplasia. We excluded hips with femoral head deformity or residual subluxation and compared the results with those from a control series of unaffected hips of patients with unilateral CDH. Acetabular development after the age of 11 or 12 years was significantly worse in Severin group III than in Severin group I hips on the affected side or Severin group III in unaffected control hips. One of the causes of acetabular dysplasia at maturity was found to be impairment of acetabular development after 11 or 12 years of age. This may be attributable to impaired secondary ossification in the acetabular rim. Our findings emphasise the importance of continuing the follow-up of patients treated for congenital dislocation of the hip until full skeletal maturity

We have reviewed the serial radiographs of 63 hips in 53 children treated by closed reduction for congenital dislocation with a view to finding a radiological measurement which can predict subsequent acetabular development. All had been followed for more than seven years, and at latest review, 34 hips were dysplastic. Failure to obtain concentric reduction or its loss by migration of the femoral head within one year of reduction were the best predictors of persisting acetabular dysplasia and were best quantitated by the h/b ratio (Smith et al. 1968). The acetabular index at reduction or its decrease in the first year were not reliable predictors. Late treatment was less likely to lead to normal acetabular development, but avascular necrosis did not appear to have a significant influence. The average age at which the acetabulum stopped developing was five years, but ranged from 17 months to eight years. The failure of a dysplastic acetabulum to improve in each annual radiograph after closed reduction should lead to consideration of operation on the acetabulum

A retrospective analysis was performed of eight patients with an open triradiate cartilage, who underwent resection for osteosarcoma and reconstruction of the proximal femur with a hemiarthroplasty, in order to identify changes of acetabular development. An analysis of the centre-edge angle, teardrop-to-medial prosthesis distance, superior joint space, teardrop-to-superior prosthesis distance, degree of lateral translation, and arthritic changes, was performed on serial radiographs. The median age at the time of the initial surgery was 11 years (5 to 14). All patients developed progressive superior and lateral migration of the prosthetic femoral head. Following hemiarthroplasty in the immature acetabulum, the normal deepening and enlargement of the acetabulum is arrested. The degree of superior and lateral migration of the prosthetic head depends on the age at diagnosis and the length of follow-up

The Bernese periacetabular osteotomy (PAO) is not indicated for growing hips as it crosses the triradiate cartilage in its posterior branch, and experimental work has shown this can induce substantial deformations, similar to posttraumatic dysplasia, which is observed after pelvis crash injuries in childhood.

Upon examination, all injuries in the 19 cases of posttraumatic dysplasia described in literature plus 16 hips of our personal collection took place before the age of 6, which is striking as pelvic injuries in children increase with age.

Based on this observation, we started to extend the PAO indication to severe dysplasias in children with open growth plate, initially aged 9 years and older. Following the positive results, it was extended further, our youngest patient being 5 years old.

We retrospectively examined radiographic outcomes of 23 hips (20 patients), aged 10.6±1.8 years [range 5.0 – 13.2], operated by us in four centers. Pre- and 3-months postoperative, and the latest FUP radiograph at growth plate closure were measured. We evaluated the acetabular index (AI), lateral center-edge (LCE), ACM-value and compared them with reference values adjusted for age. The age at triradiate cartilage closure was compared with the non-operated side.

The follow-up time was 5.4±3.7 years [0.8 - 12.7]. In 5 hips, growth plate closure was delayed by a few months. All angles significantly normalized after PAO (LCE: 14±8° → 38±11°, AI: 20±8° → 7±4°, ACM: 53±5° → 48±4°), with >80% of them severe pathological pre-PAO, none afterwards. Acetabular molding was normal. Only few complications occurred; one had signs of coxarthosis, one sciatic nerve pain, one interfering osteosynthesis material that was removed, one had an additional valgus osteotomy, and all resolved.

Based on 20 cases with follow-up until complete triradiate cartilage closure, we believe to have sufficient information to extend the PAO indication to growing hips of 9 years and older.

Aims

When the present study was initiated, we changed the treatment for late-detected developmental dislocation of the hip (DDH) from several weeks of skin traction to markedly shorter traction time. The aim of this prospective study was to evaluate this change, with special emphasis on the rate of stable closed reduction according to patient age, the development of the acetabulum, and the outcome at skeletal maturity.

Treatment of residual acetabular dysplasia is still controversial regarding the timing of Surgery, and the type of surgical procedur

Material and Methods: We analyzed 70 patients (83 hips) operated between 1980–1988 year, in which Salter innominate osteotomy was performed in the treatment of residual acetabular dysplasia in DDH. Patients were divided in two different age groups: from 2–4 (53 hips) and 4–6 (30 hips) years. The average follow up was 7 years (from 2 to 10 years). Acetabular remodeling was radiographically assessed by measuring of the Acetabular Index (AI) at the beginning and after the 5 years of age subsequently by measuring the CE angle of Wiberg. All preoperative hips were dysplastic according to Tonnis (+2SD) criteria. Results were statistically analyzed by using the Student’s T test, and One Way Repeated Measures ANOVA, with the correction for the different age groups.

Results: We found that there were no statistically significant differences in AI and CE angle between these two age groups and between these groups and normal values.

Conclusion: We recommend Salter innominate osteotomy as a procedure of choice in the treatment of acetabular dysplasia in DDH, provided the patient is younger than 6 years of age.

Salter innominate osteotomy is an effective reconstructive procedure for the treatment of developmental dysplasia of the hip (DDH), but some children have a poor outcome at skeletal maturity. In order to investigate factors associated with an unfavourable outcome, we assessed the development of the contralateral hip. We retrospectively reviewed 46 patients who underwent a unilateral Salter osteotomy at between five and seven years of age, with a mean follow-up of 10.3 years (7 to 20). The patients were divided into three groups according to the centre–edge angle (CEA) of the contralateral hip at skeletal maturity: normal (> 25°, 22 patients), borderline (20° to 25°, 17 patients) and dysplastic (<  20°, 7 patients). The CEA of the affected hip was measured pre-operatively, at eight to nine years of age, at 11 to 12 years of age and at skeletal maturity. The CEA of the affected hip was significantly smaller in the borderline and dysplastic groups at 11 and 12 years of age (p = 0.012) and at skeletal maturity (p = 0.017) than in the normal group. Severin group III was seen in two (11.8%) and four hips (57.1%) of the borderline and dysplastic groups, respectively (p < 0.001).

Limited individual development of the acetabulum was associated with an unfavourable outcome following Salter osteotomy.

Cite this article: Bone Joint J 2014;96-B:1419–23.

The purpose of this study was to investigate the development of the osseous acetabular index (OAI) and cartilaginous acetabular index (CAI) using MRI. The OAI and CAI were measured on the coronal MR images of the hip in 81 children with developmental dysplasia of the hip (DDH), with a mean age of 19.6 months (3 to 70), and 241 normal control children with a mean age of 5.1 years (1 month to 12.5 years). Additionally the developmental patterns of the OAI and CAI in normal children were determined by age-based cross-sectional analysis.

Unlike the OAI, the normal CAI decreased rapidly from a mean of 10.17° (sd 1.60) to a mean of 8.25° (sd 1.90) within the first two years of life, and then remained constant at a mean of 8.04° (sd 1.65) until adolescence. Although no difference in OAI was found between the uninvolved hips in children with unilateral DDH and normal hips (p = 0.639), the CAI was significantly different between them both (p < 0.001). The normal CAI has fully formed at birth, and is maintained constantly throughout childhood. The CAI in the unaffected hips in children with unilateral DDH is also mildly dysplastic.

The Pavlik harness (PH) is commonly used to treat infantile dislocated hips. Variability exists in the duration of brace treatment after successful reduction of the dislocated hip. In this study we evaluate the effect of prescribed time in brace on acetabular index (AI) at two years of age using a prospective, international, multicenter database. We retrospectively studied prospectively enrolled infants with at least one dislocated hip that were initially treated with a PH and had a recorded AI at two-year follow-up. Subjects were treated at one of two institutions. Institution 1 used the PH until they observed normal radiographic acetabular development. Institution 2 followed a structured 12-week brace treatment protocol. Hip dislocation was defined as less than 30% femoral head coverage at rest on the pre-treatment ultrasound or IHDI grade III or IV on the pre-treatment radiograph. Fifty-three hips met our inclusion criteria. Hips from Institution 1 were treated with a brace 3x longer than hips from institution 2 (adjusted mean 8.9±1.3 months vs 2.6±0.2 months)(p < 0 .001). Institution 1 had an 88% success rate and institution 2 had an 85% success rate at achieving hip reduction (p=0.735). At 2-year follow-up, we observed no significant difference in AI between Institution 1 (adjusted mean 25.6±0.9˚) compared to Institution 2 (adjusted mean 23.5±0.8˚) (p=0.1). However, 19% of patients from Institution 1 and 44% of patients from Institution 2 were at or below the 50th percentile of previously published age- and sex- matched AI normal data (p=0.049). Also, 27% (7/26) of hips from Institution 1 had significant acetabular dysplasia, compared to a 22% (6/27) from Institution 2 (p=0.691). We found no correlation between age at initiation of bracing and AI at 2-year follow-up (p=0.071). Our findings suggest that prolonged brace treatment does not result in improved acetabular index at age two years. Hips treated at Institution 1 had the same AI at age two years as hips treated at Institution 2, while spending about 1/3 the amount of time in a brace. We recommend close follow-up for all children treated for dislocated hips, as ~1/4 of infants had acetabular index measurements at or above the 90th percentile of normal. Continued follow-up of this prospective cohort will be critical to determine how many children require acetabular procedures during childhood. The PH brace can successfully treat dislocated infant hips, however, prolonged brace treatment was not found to result in improved acetabular development at two-year follow-up

Aim. To compare the rate and severity of avascular necrosis following medial open and closed reduction in developmental hip dysplasia and the resulting influence on femoral and acetabular development. Method. The radiographs and hospital records of 118 patients with dislocation of the hip were reviewed. 57 patients (66 hips) underwent medial open reduction and 61 patients (75 hips) underwent closed reduction. Mean follow-up was 10.9 years (5 years to 17.4 years). Avascular necrosis (AVN) was recorded according to the Bucholz and Ogden classification. The acetabular index was measured pre-operatively, at 1 and 4 years following surgery. The final radiograph was assigned a Severin grade. Sharp and centre-edge angles were recorded at final follow-up. A Severin grade I or II was considered a satisfactory result and a grade III to V an unsatisfactory result. Initial non-operative measures, such as Pavlik harness treatment and traction were documented. Additional surgical interventions were noted. Results. The rate of clinically significant AVN (types 2, 3, 4) following medial open reduction was 28.7% versus 17.3% following closed reduction. The rate of Type 2 AVN was 22.7% versus 10.6% respectively. Early acetabular development was similar in both groups. Long-term follow-up showed an unsatisfactory outcome (Severin grade III-V) following medial open reduction in 32% versus 8% in the closed reduction group. Conclusion. Our findings suggest that medial open reduction is associated with a higher rate of AVN than closed reduction. Type 2 AVN was twice as common in the medial open reduction group. More unsatisfactory results were seen in the medial open reduction group at long term follow up

Premature fusion of the triradiate cartilage was obtained surgically in 10 three-week-old rabbits, and compared with isolated fusion of the ilio-ischial and of the ilio-pubic limbs of the triradiate cartilage in two further groups of 10 rabbits. Complete fusion caused acetabular dysplasia five weeks after operation in all animals and hip dislocation at nine weeks in half of them; ilio-ischial fusion had a comparable effect. Ilio-pubic fusion had only a minimal effect on acetabular development. The posterior position of the ilio-ischial limb in the acetabulum and its predominance in the formation of the triradiate cartilage in quadrupeds may have contributed to its decisive effect on acetabular development

Aim: To compare acetabular development and hip stability over time in patients treated for developmental dysplasia of the hip (DDH) by open reduction combined with either varusderotation (VDRO) or innominate (IO) osteotomies. Method: Patients who underwent open reduction for DDH, combined with either VDRO (38 patients) or IO (33 patients), between 15 months and 4 years of age were reviewed. Both groups comprised a single surgeon consecutive series, differing only in the type of osteotomy performed. A total of 490 postoperative radiographs over a maximum follow-up period of 13.6 years were analyzed. We used repeated measures analysis of variance to compare the change in acetabular index (AI) as well as several other radiographic indices of acetabular development and hip stability over time. Results: After osteotomy, the AI decreased in both groups but the magnitude of the decrease was significantly different between groups over time (p< 0.0001). The AI of patients undergoing VDRO never decreased as much as that of patients undergoing IO, with a mean difference of 10.4 degrees after 4 years (p< 0.0001). Similarly the IO group demonstrated more favourable acetabular architecture and hip stability over time compared to the VDRO group, as quantified by change in the acetabular floor thickness (p< 0.03), lateral centring ratio (p< 0.0001) and superior centring ratio (p < 0.0001). Conclusions: Acetabular remodelling after IO was more effective at reversing acetabular dysplasia and maintaining hip stability than VDRO. Long-term follow-up of VDRO will be necessary to determine if late improvement occurs. IO may be preferable over VDRO in the treatment of hip dislocation after walking age

Introduction: A criticism of innominate osteotomy is that it causes relative acetabular retroversion, predisposing to osteoarthritis. This study was designed to address this hypothesis. Materials and Methods: We had access to radiographs of 30 patients that had undergone open reduction and innominate osteotomy for late presenting developmental hip dislocation. The patients are now middle-aged and formed part of a previously reported study on the long term outcome of this protocol. Standardised, well-centered anteroposterior standing hip radiographs had been obtained. We used the validated method of Hefti (1995) to measure anterior and posterior acetabular coverage and contact area. All measurements were made by a single independent investigator. Results: 10 operated hips had advanced osteoarthritis which made it impossible to identify acetabular landmarks. 26 hips were readable despite signs of mild to moderate osteoarthritis in some (Group A). 20 contra-lateral hips without DDH which appeared radiographically normal formed control group B. Discussion: We were unable to assess operated hips which had gone on to replacement or severe osteoarthritis. This is a flaw as those hips with better radiographs have been selected out for study. Nonetheless this was a unique opportunity to assess the effect of innominate osteotomy on acetabular development in good numbers of hips with a variety of evolved outcomes. Conclusion: Acetabular coverage and load area in hips with a good outcome after innominate osteotomy with open reduction were not different to a control group of radiographically normal hips without previous DDH. Innominate osteotomy before the age of 5 years has the potential to facilitate, or at least not prevent, normal acetabular development and version

Normal acetabular development in developmental dysplasia of the hip (DDH) depends upon early and maintained congruent reduction. Computed tomography is an accepted method for evaluating this and attempts to quantify hip reduction, by various angular and linear measurements, have been reported. The aim of this study was to assess initial CT scans, following open reduction in the older child with DDH, with comparison of outcome to evaluate prognostic value. Method: Thirty consecutive patients underwent open reduction for DDH, with a mean age of 25.9 months at the time of operation. Acetabular morphology and the position of the femoral head were evaluated on the initial CT scan, taken on the first postoperative day, and AP pelvic radiograph taken at the latest follow-up. Results: The acetabulae of the dislocated hips were found to be significantly more anteverted than the normal. The dislocated hips also had significantly increased lateral displacement both initially and at latest follow-up. Posterior displacement of the proximal femoral metaphysis should raise concern due to an association with the need for further surgical intervention. These results did not however correlate with outcome. In conclusion, despite the significant differences noted between DDH and normal hips they did not predict acetabular development or persistent acetabular dysplasia

Purpose: The aim of this prospective controlled study was to assess the natural history of acetabular development in D.D.H. treated under 18 months of age. Method: For this purpose, patients who were treated using a posteromedial approach soft tissue surgical procedure due to unilateral D.D.H., had intraoperative radiographic anatomic reductions, had neither any type of avascular necrosis of the femoral head nor breakage of the Shenton’s line during the follow-up period, had complete follow-up till at least 10 years of age and had normal center-edge angles at the latest follow-up were selected from a prospective series that started in December 1993. Unaffected contrlateral hips were used as controls. Fourteen hips of 14 patients (13 females and 1 male) met the above mentioned strict criteriae and included the study. Acetabular angle of Sharp (AA) was measured to assess the acetabular slope in the frontal plane preoperatively and during follow-up. A paired t-test was used for the statistical analysis of the data and a P value less than 0.05 was considered significant. Conclusion: In anatomically reduced and uncomplicated dysplastic hips which have been treated under 18 months of age, acetabular slope in the frontal plane tends to improve continuosly till at least 10 years of age and reaches to similar angular values as in the unaffected hips at nearly 7 years of age. In such hips, it may not be appropriate to make a final decision on whether the acetabular development is sufficient or not before 7 years of age

The February 2023 Children’s orthopaedics Roundup³⁶⁰ looks at: Trends in management of paediatric distal radius buckle fractures; Pelvic osteotomy in patients with previous sacral-alar-iliac fixation; Sacral-alar-iliac fixation in patients with previous pelvic osteotomy; Idiopathic toe walking: an update on natural history, diagnosis, and treatment; A prediction model for treatment decisions in distal radial physeal injuries: a multicentre retrospective study; Angular deformities after percutaneous epiphysiodesis for leg length discrepancy; MRI assessment of anterior coverage is predictive of future radiological coverage; Predictive scoring for recurrent patellar instability after a first-time patellar dislocation.

The December 2024 Children’s orthopaedics Roundup³⁶⁰ looks at: Establishing best practice for managing idiopathic toe walking in children: a UK consensus; Long-term outcomes of below-elbow casting in paediatric diaphyseal forearm fractures; Residual dysplasia risk persists in developmental dysplasia of the hip patients after Pavlik harness treatment; 3D printing in paediatricorthopaedics: enhancing surgical efficiency and patient outcomes; Pavlik harness treatment for hip dysplasia does not delay motor skill development in children; High prevalence of hip dysplasia found in adolescents with idiopathic scoliosis on routine spine radiographs; Minifragment plates as effective growth modulation for ulnar deformities of the distal radius in children; Long-term success of Chiari pelvic osteotomy in preserving hip function: 30-year follow-up study.

Aims

Radiological residual acetabular dysplasia (RAD) has been reported in up to 30% of children who had successful brace treatment of infant developmental dysplasia of the hip (DDH). Predicting those who will resolve and those who may need corrective surgery is important to optimize follow-up protocols. In this study we have aimed to identify the prevalence and predictors of RAD at two years and five years post-bracing.