The surgical treatment of established congenital dislocation of the hip: results of surgery after planned delayed intervention following the appearance of the capital femoral ossific nucleus

Outcomes following medial open reduction in infants aged ≤6 months with developmental dysplasia of the hip

Aim

To evaluate mid-long term radiological outcomes following early medial approach open reduction (MAOR) performed for developmental dysplasia of the hip (DDH) in infants aged ≤6 months old at time of surgery, specifically incidence of clinically significant avascular necrosis (AVN), Severin outcomes and rates of further surgery.

Methods

This is a single centre retrospective study of patients treated from 1999 to 2017. Only infants aged ≤6 months old at time of MAOR, and aged at least 6 years old at latest follow-up were included (minimum 5.5 years follow-up). Data was collected from electronic healthcare records and serial radiographs reviewed to assess outcomes. AVN was classified according to Kalamchi and MacEwen, with types 2-4 considered clinically significant. Severin classes I (excellent) and II (good) were considered satisfactory outcomes, and classes III + considered unsatisfactory.

Results

MAOR was performed on 48 hips in 44 patients. Mean age at time of surgery was 4 months (SD 1.4, range 2-6), with mean follow-up of 9.8 years (SD 2.7, range 6.2-16.2). Clinically significant AVN developed in 9/48 hips (19 %), all of which were type 2. Only 1/48 hips (2 %) required a subsequent pelvic osteotomy due to residual dysplasia with subluxation at 2 years post MAOR. At final follow-up, 81 % of patients had excellent or good radiological outcomes (Severin I/II). No statistically significant predictors for developing AVN, including age and presence of ossific nucleus, were identified.

Conclusion

Early MAOR in infants aged ≤6 months was associated with a very low rate of significant residual dysplasia requiring further surgery, yet was not associated with unacceptable rates or severe forms of AVN. We therefore recommend MAOR is performed early to optimise acetabular remodelling potential and minimise the need for concurrent or subsequent bony procedures.

Risk factor analysis of femoral avascular necrosis after operation for Tönnis grade IV developmental dysplasia of the hip

PURPOSE

We explored the risk factors for avascular necrosis (AVN) after surgery using open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV developmental dysplasia of the hip (DDH).

METHODS

In this retrospective study, we collected data of patients with Tönnis grade IV DDH treated with open reduction and pelvic osteotomy combined with femoral osteotomy from January 2012 to May 2020. The patients were divided into the AVN group and non-AVN group using the Kalamchi-MacEwen classification system. The clinical and imaging data of the two groups were collected, and the possible risk factors were included in the analysis. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors and odds ratios of AVN.

RESULTS

In all, 254 patients (mean age; 2.6±0.9 years, 278 hips) were included. The mean follow-up time was 3.8±1.5 years. A total of 89 hips (32%) were finally classified as AVN (Kalamchi-MacEwen II-IV). Univariate analysis showed significant associations with AVN for age (p=0.006), preoperative femoral neck anteversion (FAV) (p<0.001), femoral osteotomy length to dislocation height ratio (FDR) <1 (p<0.001), and the epiphyseal ossific nucleus diameter to the neck diameter ratio (ENR) <50% (p=0.009). Multivariate logistic regression analysis showed that only excessive preoperative FAV (OR: 1.04; 95% CI: 1.02-1.05; p<0.001) and FDR<1 (OR: 3.58; 95% CI: 2.03-6.31; p<0.001) were independent risk factors for femoral head necrosis.

CONCLUSION

Excessive preoperative FAV and FDR<1 are important risk factors for femoral AVN after open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV DDH. For children with DDH with high dislocation and excessive FAV, clinicians should fully evaluate their condition and design more personalized treatment programs to prevent AVN.

Open reduction after failed closed reduction following failed Pavlik harness treatment in developmental dysplasia of the hip: One- or two-stage?

INTRODUCTION

The current published evidence for the treatment of developmental dysplasia of the hip (DDH) with failed closed reduction (CR) following failed Pavlik harness (PH) treatment is still limited. This study aimed to determine whether an one-stage open reduction (OR) would lead to a similar outcome to a two-stage OR in these patients. Meanwhile, the occurrence of femoral head avascular necrosis (AVN) and further surgery (pelvic osteotomy, PO) within the follow-up period was investigated.

MATERIALS AND METHODS

A consecutive series of DDH patients who failed CR following failed PH treatment and received OR finally between January 2008 and December 2020 were studied. The patients were divided into two groups. One group of which received OR immediately after failed CR (one-stage OR group, Group A), and the other received a delayed OR (two-stage OR group, Group B). The McKay's criteria, acetabular index (AI) and the degree of dislocation of the hips were evaluated for the final outcomes.

RESULTS

At the last follow-up, 54 (84.4%) of the 64 hips in Group A and 26 (83.9%) of 31 hips in Group B were in excellent or good condition. Comparison between the two groups revealed that there were no differences in terms of McKay grading (P = 0.950), AI (P = 0.783), incidence of AVN (P = 0.745), and also incidence of PO (P = 1.000). However, a significant lower mean AI was found in Group A, when the OR was performed in Group B (31.06 ± 4.45° vs. 33.87 ± 4.12°, P = 0.004).

CONCLUSION

Both of the one- and two-stage OR may acheive favorable outcomes. Moreover, one-stage OR is of without the general anesthesia risk associated with two-stage OR. We therefore advocate that an OR should be performed in appropriate DDH patients during the same session once a failed CR is detected.

Avascular necrosis predictive factors after closed reduction in patients with developmental dysplasia of the hip

Background

Developmental dysplasia of the hip (DDH) is a common pediatric orthopedic condition. Closed reduction (CR) is the conservative treatment approach with high success rates for DDH. However, avascular necrosis (AVN) is a severe potential complication after this procedure. This study retrospectively assessed the potential risk factors for AVN occurrence after CR and Spica cast immobilization.

Materials and Methods

In a retrospective observational study, 71 patients (89 hips) with DDH aged 6-24 months old undergoing CR were enrolled. All patients were followed up for 3 years, and their demographic data, initial Tönnis grade, pre-reduction procedures, abduction angle in the Spica cast, and the AVN presence (based on Bucholz and Ogden classification [3rd-4th class]) were documented.

Results

Of 71 patients (89 hips) with a mean age of 12.5 ± 3.9 months, 13 patients (18 hips) developed AVN. The mean age of patients in the AVN and non-AVN groups was 14.3 ± 4.9 and 12.2 ± 3 months (P = 0.07); also, the mean abduction angle in patients with and without AVN was 51.86 ± 3.66 and 58.46 ± 3.91 (P < 0.001) in univariate analysis. The distribution of initial Tönnis grade, and previous conservative procedures, adductor tenotomies during the CR were comparable between the two groups (P > 0.05). We found age 12 months and 54° in abduction angle as the best cutoff values for differentiating AVN patients from non-AVN and the risk of experiencing AVN for patients older than 12 months was odds ratio (OR) =4.22 (P = 0.06) and patients with abduction angle greater than 54 was OR = 34.88 (P < 0.001).

Conclusion

In this study, older age at the time of intervention and larger abduction angle in the hip Spica cast were two predictors of experiencing AVN in DDH patients after undergoing CR treatment approach. Performing CR at a younger age and keeping the abduction angle lower than 54° in the hip Spica cast could help to have the best possible prognosis.

Level of Evidence

IV, retrospective, observational, cross-sectional study.

Outcomes of Open Reduction in Children With Developmental Hip Dislocation: A Multicenter Experience Over a Decade

BACKGROUND

Open reduction of the hip is commonly performed in children with severe developmental dysplasia of the hip, or in cases that are refractory to nonoperative forms of treatment. The open reduction has been associated with numerous complications including avascular necrosis (AVN) of the femoral head, the need for reoperation, and residual radiographic dysplasia. This study seeks to determine the effects of preoperative severity of dysplasia, associated procedures (femoral and acetabular osteotomies), age on AVN, and the need for reoperation.

METHODS

Children with developmental dysplasia of the hip and a minimum of 2 years of follow-up who underwent open reduction were identified. The following data points were recorded: sex, laterality of hip involvement, simultaneous procedures, surgical approach used, age, acetabular index, and International Hip Dysplasia Institute grade. We analyzed the effects of preoperative International Hip Dysplasia Institute, age, surgical approach (anterior/medial), bilateral reduction, and simultaneous femoral shortening or pelvic osteotomy on the outcomes of AVN and reoperation.

RESULTS

One hundred eighty-five hips in 149 patients were included in this study with an average follow-up of 4 years (range: 2 to 5 y). The average age at index surgery was 23 months (range: 1 to 121 mo). Overall, 60 hips (32.4%) required secondary surgical procedures at an average age of 58.5 months. High-grade AVN was noted in 24 hips (13.0%) and was found to be associated with the severity of the hip dislocation ( P = 0.02). A higher rate of reoperation was found in children over 18 months at the time of open reduction who did not receive an acetabular osteotomy ( P = 0.012).

CONCLUSION

Approximately 1/3 of patients require another operative intervention within the first 4 years after open reduction of the hip. We found the severity of hip dislocation to be associated with a higher risk of AVN development. These findings support performing an acetabular osteotomy in children over 18 months of age at the time of open reduction to decrease the likelihood of requiring future reoperation during the first 4 years after the index procedure.

LEVEL OF EVIDENCE

Level III.

A Prospective, Multicenter Study of Developmental Dysplasia of the Hip: What Can Patients Expect After Open Reduction?

BACKGROUND

Although there are several predominantly single-center case series in the literature, relatively little prospectively collected data exist regarding the outcomes of open hip reduction (OR) for infantile developmental dysplasia of the hip (DDH). The purpose of this prospective, multi-center study was to determine the outcomes after OR in a diverse patient population.

METHODS

The prospectively collected database of an international multicenter study group was queried for all patients treated with OR for DDH. Minimum follow-up was 1 year. Proximal femoral growth disturbance (PFGD) was defined by consensus review using Salter's criteria. Persistent acetabular dysplasia was defined as an acetabular index >90th percentile for age. Statistical analyses were performed to compare preoperative and operative characteristics that predicted re-dislocation, PFGD, and residual acetabular dysplasia.

RESULTS

A cohort of 232 hips (195 patients) was identified; median age at OR was 19 months (interquartile range 13 to 28) and median follow-up length was 21 months (interquartile range 16 to 32). Re-dislocation occurred in 7% of hips (n=16/228). The majority (81%; n=13/16) occurred in the first year after initial OR. Excluding patients with repeat dislocation, 94.5% of hips were IHDI 1 at most recent follow-up. On the basis of strict radiographic review, some degree of PFGD was present in 44% of hips (n=101/230) at most recent follow-up. Seventy-eight hips (55%) demonstrated residual dysplasia compared with established normative data. Hips that had a pelvic osteotomy at index surgery had about half the rate of residual dysplasia (39%; n=32/82) versus those without a pelvic osteotomy with at least 2 years follow-up (78%; n=46/59).

CONCLUSIONS

In the largest prospective, multicenter study to date, OR for infantile DDH was associated with a 7% risk of re-dislocation, 44% risk of PFGD, and 55% risk of residual acetabular dysplasia at short term follow-up. The incidence of these adverse outcomes is higher than previous reports. Patients treated with concomitant pelvic osteotomy had lower rates of residual dysplasia. These prospectively collected, multicenter data provide better generalizable information to improve family education and appropriately set expectations.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Risk Factors for Avascular Necrosis After Closed Reduction for Developmental Dysplasia of the Hip

BACKGROUND

Avascular necrosis (AVN) is a major complication after closed reduction for developmental dysplasia of the hip. The factors that predispose to AVN remain controversial. The purpose of this study was to analyze the risk factors, especially patient factors, such as age at reduction, grade of dislocation, and ossific nucleus development, related to AVN.

MATERIALS AND METHODS

We retrospectively reviewed children with dysplasia of the hip treated by closed reduction between 1997 and 2006. AVN was evaluated using Salter criteria and Kalamchi and MacEwen classification. Related factors were analyzed.

RESULTS

One hundred and eight children (140 hips) with an average age of 16.6 months at closed reduction (range: 6-24 mo) were included in the study. For an average duration of 10.1 years (range 7-16 y) of follow-up, 44 hips (31.4%) developed AVN. Grade II or higher AVN occurred in 14 hips (10%). The incidence of AVN increased with the grade of dislocation ( P =0.022) and underdevelopment of the ossific nucleus ( P <0.001). Underdevelopment of the ossific nucleus was also found to be positively correlated with the dislocation grade ( P =0.047). The age at the time of reduction, sex, and side were not significant factors. Children who underwent secondary operation were all older than 1 year at reduction.

CONCLUSIONS

High-grade dislocation correlates with the underdevelopment of the ossific nucleus. Patients with these 2 characteristics are predisposed to AVN. As underdevelopment of the ossific nucleus occurred regardless of age, it is not advisable to delay reduction because it does not alter the AVN rate, and instead, it increases the secondary operation rate.

LEVEL OF EVIDENCE

Level IV case series.

Avascular necrosis under different treatment in children with developmental dysplasia of the hip: a network meta-analysis

The objective of this study was to evaluate the incidence of avascular necrosis (AVN) of the femoral head in children less than 3 years of age with developmental dysplasia of the hip (DDH) treated with closed reduction, open reduction alone and open reduction combined with osteotomy. We reviewed clinical trials from the PubMed, EMBASE and Cochrane Library databases (up to November 2020) that were related to closed reduction, open reduction alone and open reduction combined with osteotomy for the treatment of children under 3 years of age with DDH. The screening and quality evaluation of the literature were performed independently by two researchers. In case of disagreement, a third researcher resolved the discourse. Finally, the data were extracted, and the R software and GeMTC program package were used to conduct a network meta-analysis (NMA). The evaluation index was the incidence of AVN. Fourteen articles were included. The NMA showed that in terms of the incidence of AVN, cases treated with open reduction alone were higher than those with closed reduction, and the difference was statistically significant. Open reduction alone had the highest probability (94.4%) of having the highest incidence of AVN, followed by open reduction combined with osteotomy (5.5%) and closed reduction (0.1%). In the treatment of children with DDH who are younger than 3 years old, open reduction alone is most likely to be the treatment with the highest incidence of AVN, followed by open reduction combined with osteotomy. The closed reduction had the smallest probability of AVN.

Minimally Invasive Surgery to Remove a Broken and Retained Epidural Catheter Fragment

Epidural anaesthesia (EA) has consistently been used for treatments affecting the pelvis, lower limbs, lower abdomen, and perineum; however, it is progressively employed as a single anaesthetic or supplement to general and spinal anaesthesia for a broader range of procedures. The retention of a broken epidural catheter piece is an uncommon but well-known complication. In this report, we present a 30-year-old male with avascular necrosis (AVN) of the hip who was referred for total hip replacement (THR). An epidural catheter had been placed at the presumed L2-3 interspace to administer EA. The catheter had been set too deep and it broke on extraction with the Tuohy needle, leaving a fragment inside. The patient was then given general anaesthesia and the planned procedure of THR was done in the lateral position. The patient was then shifted to the prone position to remove the retained fragment of the epidural catheter by a minimally invasive spinal surgery (MISS). Right-sided L2 laminotomy was done, as the epidural catheter was inserted from the right side, to retrieve the broken fragment without any added postoperative neurological complications. MISS may be attempted by experienced surgeons for the removal of a retained fragment of the epidural catheter from the spinal canal before adhesion as a safe option.

The Clinical Significance of Infolded Limbus on Postreduction Arthrogram in Developmental Dysplasia of the Hip

BACKGROUND

The purpose of this study was to investigate whether presence of an infolded limbus on hip arthrogram at index closed reduction was associated with increased residual dysplasia or secondary surgery.

METHODS

We retrospectively reviewed all patients who underwent closed reduction for dysplasia of the hip with a minimum 2-year follow-up between 1980 and 2016. Demographic data was obtained including the age at reduction and severity of dislocation based on the International Hip Dysplasia Institute (IHDI) classification. Arthrograms performed at time of closed reduction were separately reviewed by 3 fellowship-trained pediatric orthopaedic surgeons to evaluate for an infolded limbus. The primary radiographic outcome was acetabular indices at 2 and 4 years postreduction. We also assessed the presence of avascular necrosis and rate of secondary reconstructive surgery for residual dysplasia.

RESULTS

A total of 182 hips in 165 patients underwent closed reduction at a mean age of 9.8±4.5 mo and were followed a mean of 9.0±4.9 y. An infolded limbus was identified in 20.3% (37/182) hips with substantial agreement among the 3 graders (Fleiss κ=0.75). The frequency of labral infolding increased with the severity of dislocation (8.8%% of IHDI II, 26.7% IHDI III, and 25.0% of IHDI IV hips; P=0.03). Hips with infolded limbus were older at reduction (12.4±5.3 vs. 9.2±5.8 mo, P=0.001). The mean acetabular index was higher in hips with infolded limbus than hips without at 2 years postreduction (34.8±4.8 vs. 32.6±5.8 degrees, respectively; P=0.04). However, multivariate analysis revealed that only the severity of dislocation predicted dysplasia at 2 years postreduction. No significant difference in acetabular index was seen at 4 years postreduction (27.2±7.4 vs. 25.4±6.5 degrees, P=0.24). There was no difference in avascular necrosis between groups (P=0.74). There was no difference in rate of secondary surgery between hips with labral infolding and those without (35% vs. 30%, respectively; P=0.52).

CONCLUSIONS

An infolded limbus was more common in older patients with more severe dislocations. However, it is not associated with increased residual dysplasia or secondary surgery and may have limited utility in decision-making during closed reduction.

LEVEL OF EVIDENCE

Level II-prognostic study.

Narrative Review of Complications Following DDH Treatment

BACKGROUND

The purpose of this narrative review was to survey the literature for common complications following treatment of DDH in children less than 4 years old.

METHODS

The Pubmed database was queried. Search result titles were reviewed to identify papers that were pertinent to the topic. Abstracts for these papers were obtained and read, and a subset of these were selected for review of the complete manuscript.

RESULTS

92 manuscripts were reviewed. Residual dysplasia, redislocation, and osteonecrosis are the primary complications of treatment in this age group. In the long term, hips without complications related to DDH treatment tend to do well, although a significant percentage of them will inevitably require joint replacement surgery.

CONCLUSION

Although there is excellent potential for a good outcome when DDH is diagnosed and treated under age 4 years, osteonecrosis continues to be a concern with all treatment methods. A subset of patients from this young cohort will continue to have residual dysplasia or recurrent dislocation requiring return to the operating room.

DDH in the Walking Age: Review of Patients with Long-Term Follow-Up

INTRODUCTION

The best treatment option in children with late detected DDH is still a subject of much controversy and only few studies have investigated the long-term outcome of treatment in such patients. We performed a systematic review to assess long-term outcome of late detected DDH hips treated after walking age.

METHODS

Studies met inclusion criteria if they: (1) reported at least 30 hips treated; (2) included children aged between 9 months and 12 years; (3) treatment indication was late detected DDH after walking age; (4) presented a minimum follow-up of 10 years; (5) reported a clinical or radiological outcome. The Kaplan-Meier method was used to evaluate long-term survival according to clinical and radiological outcomes. The rate of total hip replacement (THR) was retrieved.

RESULTS

From a total of 6561 articles, 13 articles with grade IV level of evidence were included in our review. A total of 988 hips in 800 patients with a mean follow-up of 27.9 years (range 10-67) were included. The mean age at surgery was 3.3 years (range, 9 months-12 years). The rate of THR increased according to the length of final follow-up. In particular, all studies reported no case of THR at 23.5 years of follow-up, a rate of 10.2% of THR between 30 and 40 years of follow-up and a rate of 35.6% of THR in patients with follow-up more than 40 years.

CONCLUSIONS

In patients with late detected DDH, most THR became necessary more than 30 years after the index procedure and their number increased further after 40 years and more of follow-up. Late detected DDH diagnosed after walking age is a life-long disease.

The incidence of avascular necrosis following a cohort of treated developmental dysplasia of the hip in a single tertiary centre

PURPOSE

Avascular necrosis (AVN) may occur following treatment for developmental dysplasia of the hip (DDH). The primary aim of this study was to identify the incidence of AVN in a cohort of patients treated for DDH. Secondary aims were to classify AVN using available classification systems, analyze the correlation between the systems and investigate their relationship with the age at diagnosis of DDH.

METHODS

An 11-year retrospective study was carried out at a single tertiary centre, using data from the clinical portal (patient records database) and IMPAX (system used to store plain radiographic images). Clinical details (patient demographics and outcomes) and plain radiographic images were used to identify cases of DDH and categorize cases of AVN using available classification systems: Tonnis and Kuhlmann, Kalamchi and McEwen, Bucholz and Ogden and Salter. Severin was used to assess final clinical outcome.

RESULTS

In total, 405 (522 hips) cases of DDH were identified, of which 213 resolved without treatment, 93 were treated conservatively and 99 surgically. Only treated cases were included in the analysis (n = 192). AVN (45/99; 45.5%) was found to occur only postoperatively. A positive correlation was present between age at presentation and severity of AVN as classified according to Salter's criteria (chi-squared p value < 0.01).

CONCLUSION

AVN incidence was 23.4% (45/192) and only occurred in surgically treated patients. Older age at diagnosis was associated with a higher incidence of AVN, as defined according to Salter's criteria. The classification systems appeared to show no correlation amongst each other (p-value < 0.01).

LEVEL OF EVIDENCE

III - Retrospective cohort study.

The presence of the ossific nucleus and its relation to avascular necrosis rates and the number of secondary procedures in late-presenting developmental dysplasia of the hip

Late-presenting developmental dysplasia of the hip (DDH) has an incidence reported between 0.07 and 2:1000 live births. Avascular necrosis (AVN) of the femoral head secondary to treatment of DDH is a feared complication and may lead to adverse long-term sequelae. This study aims to investigate the relationship between the ossific nucleus (ON) presence and AVN in late-presenting DDH. This is a retrospective study of prospectively collected data over a 24-year period, at a single UK centre. Late-presenting DDH who were treated surgically with a closed or open reduction were included in the series. The presence of ON was monitored, and outcomes measured included AVN and whether delaying surgery affected the number of secondary procedures. Seventy-six patients with 79 hips (mean age at presentation 13.8 months) were included in the analysis. The mean age at presentation was 13.8 months. About 45.5% of hips with no ON present developed clinically significant AVN (Kalamchi and MacEwen grades 2-4, P = 0.12), compared to 20.6% of hips with the ON present. Delaying surgery did not affect AVN rates or the number of secondary procedures. Looking at long-term outcomes, 86.7% of hips had a Severin grade of I or II and 13.3% had a grade ≥III. Factors that affected long-term outcomes were absent ON (P = 0.04) and open reduction (P = 0.03). In the multiple logistic regression model, only open reduction could increase AVN rates (P value 0.027). The presence of ON at the time of surgery may have an impact on the rate and significance of AVN. Absence of the ON at the time of reduction negatively affects long-term outcomes in late-presenting DDH.

Secondary Surgery and Residual Dysplasia Following Late Closed or Open Reduction of Developmental Dysplasia of the Hip

BACKGROUND

Outcomes studies following successful closed reduction of late-detected developmental dysplasia of the hip (DDH) reveal high rates of secondary reconstructive surgery with limited comparative data demonstrating lower rates of residual dysplasia with open reduction. The purpose of this study was to compare long-term outcomes, with regard to radiographic evidence of residual dysplasia and secondary reconstructive procedures, between late closed and late open reduction for DDH in patients 6 to 24 months of age at reduction.

METHODS

We identified all patients between 6 and 24 months of age who underwent closed or open reduction for DDH between 1980 and 2008 and were followed until at least 10 years of age. Outcomes included radiographic measurement of acetabular dysplasia after triradiate cartilage closure, development of osteonecrosis, and the need for secondary procedures for residual dysplasia.

RESULTS

One hundred and four hips underwent index closed reduction and 54 hips underwent index open reduction. There was no significant difference in the age at reduction (p = 0.07). Among the 116 hips for which initial anteroposterior pelvic radiographs were available, most closed reductions (55%) were performed in International Hip Dysplasia Institute (IHDI) grade-III hips whereas most open reductions (71%) were performed in IHDI grade-IV hips. Analysis of the hips that did not undergo a secondary procedure showed that those with an index open reduction had a greater lateral center-edge angle (mean and standard deviation, 27.2° ± 10.0° versus 22.4° ± 6.8° in the closed reduction cohort; p = 0.02), lower femoral head extrusion index (22.2% ± 8.9% versus 26.0% ± 6.2%; p = 0.04), and lower Sharp angle (43.3° ± 6.0° versus 46.6° ± 3.1°; p = 0.002) at triradiate closure. There was no difference in the prevalence of osteonecrosis (Bucholz-Ogden grades II, III, and IV) between the closed and open reduction cohorts (22% versus 19%, respectively; p = 0.60). Secondary procedures were performed more frequently after closed reduction than after open reduction (47% versus 30%, respectively; p = 0.03).

CONCLUSIONS

In patients with late reduction of DDH, closed reduction was associated with increased residual dysplasia and it was associated with a higher rate of secondary surgery in those >12 months old despite a decreased severity of displacement based on the IHDI classification. Additional, prospective studies with assessment of functional outcomes are needed to validate these findings.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A Comparative Study of Clinical and Radiological Outcomes of Open Reduction Using the Anterior and Medial Approaches for the Management of Developmental Dysplasia of the Hip

BACKGROUND

The literature is scanty on reports directly comparing the outcomes of anterior open reduction (AOR) and medial open reduction (MOR) in the management of developmental dysplasia of the hip (DDH).

PURPOSE OF THE STUDY

To compare clinical and radiographic outcomes of surgical treatment using either AOR or MOR in children with DDH aged < 24 months and to evaluate the procedure-inherent risks of avascular necrosis of the femoral head (AVN) and need for further corrective surgery (FCS).

METHODS

61 children who underwent surgical treatment for DDH were categorized into two groups: AOR (31 hips of 28 patients) and MOR (39 hips of 33 patients). The mean age was 17 ± 5.85 (range 7-24) months in group AOR and 13 ± 5.31 (range 6-24) months in group MOR. The mean follow-up was 118 ± 41.2 (range 24-192) months and 132 ± 36.7 (range 24-209) months in group AOR and MOR. At the final follow-up, mid- to long-term clinical and radiographic outcomes were assessed. FCS was recorded.

RESULTS

Regarding McKay's clinical criteria, both groups exhibited similar results (p = 0.761). No significant differences were observed between the groups in both the center-edge-angle (p = 0.112) and the Severin score (p = 0.275). The AVN rate was 32% in the AOR group and 20% in the MOR group (p = 0.264). The FCS rate was 22% in the AOR group and 12% in the MOR group (p = 0.464).

CONCLUSIONS

This study showed similar clinical and radiological outcomes with AOR and MOR with no significant relation to AVN and FCS.

LEVEL OF EVIDENCE

Level III.

Does the size of the femoral head correlate with the incidence of avascular necrosis of the proximal femoral epiphysis in children with developmental dysplasia of the hip treated by closed reduction?

PURPOSE

The purpose of this study was to identify if any correlation between size of the proximal femoral epiphysis and avascular necrosis (AVN) exists.

METHODS

We retrospectively reviewed 111 patients with developmental dysplasia of the hip treated by closed reduction (124 hips). The diameter and height of both femoral head and ossific nucleus were assessed on preoperative MRI.

RESULTS

The diameter and the height of the femoral head as well as of the ossific nucleus of the contralateral side were significantly greater than the dislocated side. AVN occurred in 21 (16.9%) out of 124 hips. The rate of AVN gradually decreased with age: 30.0% at six to 12 months, 18.2% at 12 to 18 months and 3.7% at 18 to 24 months. Spearman correlation analysis showed that age is negatively correlated with the incidence of AVN (r = -0.274; p = 0.002) and the diameter of the femoral head has a significantly negative association with the incidence of AVN (r = -0.287; p = 0.001). No significant association was observed between the incidence of AVN and height of the femoral head or size of the ossific nucleus. Hips with AVN were significantly smaller than hips without AVN.

CONCLUSIONS

The size of both the femoral head and the ossific nucleus increase with age although the dislocated femoral head is smaller compared with the contralateral side. The diameter of the femoral head and not the size of the ossific nucleus negatively correlate with the risk of AVN, with a bigger femoral head showing lower risk of AVN.

LEVEL OF EVIDENCE

III.

Salter osteotomy without open reduction in the Tönnis type II developmental hip dysplasia: A retrospective clinical study

PURPOSE

We aimed to evaluate the clinical and radiological outcomes of children older than 18 months who were treated with Salter osteotomy without open reduction for Tönnis type II hip dysplasia.

METHODS

Thirty-two type II hips of 24 patients were included in the study. The mean age was 43.22 (18-108) months. The mean follow-up period was 50 (24-142) months. Seven patients had left sided, nine had right sided, and eight had bilateral developmental dysplasia of the hip. All patients underwent closed reduction and Salter osteotomy. Preoperative and postoperative radiographs were assessed by measuring the center-edge (CE) angle of Wiberg, Smith's c/b and h/b ratio, and acetabular index (AI). Patients were evaluated clinically according to McKay's criteria and radiologically according to Severin criteria. The Kalamchi and MacEwen criteria were used in the evaluation of avascular necrosis.

RESULTS

The mean preoperative AI, CE angle, c/b, and h/b ratio were 36.7° (±4.1), 7.2° (±5.9), 0.9 (±0.08), and 0.05 (±0.04), respectively. The mean latest follow-up AI, CE angle, c/b, and h/b ratio were 18.2° (±1.7), 38.8° (±5.4), 0.6 (±0.03), and 0.19 (±0.04), respectively. The comparison of preoperative and postoperative radiological values revealed statistically significant improvement ( p < 0.01). On the latest physical examinations of the patients, 25 (78.1%) hips were rated excellent, and 7 (21.9%) were rated good according to the McKay criteria. The Severin classification determined 25 (78.1%) hips were grade I and 7 (21.9%) hips were grade II. Type I avascular necrosis (AVN) was seen in four (12.5%) hips. Three of these four hips were more superolateral in preoperative radiographs (c/b > 1 and h/b < 0.05).

CONCLUSIONS

Salter osteotomy without open reduction is a good surgery option for Tönnis type II hip dysplasia, in which closed reduction can be performed. However, the risk of AVN should be kept in mind in more superolateral type 2 hips.

Effect of abduction on avascular necrosis of the femoral epiphysis in patients with late-detected developmental dysplasia of the hip treated by closed reduction: a MRI study of 59 hips

PURPOSE

The purpose of this study was to explore whether increasing the hip abduction angle would increase the incidence of avascular necrosis (AVN) in patients with late- detected developmental dysplasia of the hip (DDH) treated by closed reduction (CR) and spica cast immobilization.

METHODS

A total of 55 patients (59 hips) with late-detected DDH underwent MRI after CR. Hip abduction angle and hip joint distance were measured on postoperative MRI transverse sections. The acetabular index and centre-edge angle were measured on plain radiographs at the last follow-up. The presence of AVN according to Kalamchi and McEwen's classification was assessed. We retrospectively analyzed the associations among abduction angles, hip joint distances, radiographic parameters, AVN and final outcomes, exploring the relationship between hip joint abduction angle and AVN rate.

RESULTS

The mean age at the time of CR was 14.4 months SD 5.5 (6 to 28), and the mean follow-up was 26.2 months SD 8.1 (12.4 to 41.7). The mean hip abduction angle was 70.2° SD 7.2° (53° to 85°) on the dislocated side and 63.7° SD 8.8° (40° to 82°) on the normal side; the mean hip joint distance was 5.1 mm SD 1.9 (1.3 to 9.1) on the dislocated side and 2.2 mm SD 0.6 on the normal side (1.3 to 3.3). Eight of 59 hips (13.6%) developed AVN. Neither the amount of abduction nor hip joint distance increased the AVN rate (p = 0.97 and p = 0.65, respectively) or the dislocation rate (p = 0.38 and p = 0.14, respectively).

CONCLUSION

Abduction angle up to 70.2° following CR did not increase the AVN rate in children aged six to 28 months with late-detected DDH treated by CR.

LEVEL OF EVIDENCE

III.

Comparison of arthroscopic and open reduction of conservatively irreducible dislocated hips of children

PURPOSE

Children with sonographic grade IV hip dysplasia according to Graf and with failed conservative treatment usually need surgical reduction afterwards. Surgical reduction of the hip can lead to severe complications, the occurrence of residual acetabular dysplasia, osteonecrosis, redislocation and other postoperative complications. This paper investigates whether arthroscopic reduction is a promising alternative to open reduction.

METHODS

We retrospectively examined 66 patients (78 hips) who were not older than two years at the first time of surgery. Arthroscopic reduction was performed on 17 children (19 hips) and open reduction on 49 children (59 hips). Patient records were used to determine redislocation, postoperative complication and residual dysplasia. Radiographs were used to determine Tönnis classification for osteonecrosis and pathological acetabular (AC) angle for residual dysplasia. We considered data up to a two-year follow-up. Statistical evaluation was performed with binary logistic regression.

RESULTS

After arthroscopic reduction, 6% showed osteonecrosis, compared with 20% with open reduction (p = 0.334). Redislocation was not observed after arthroscopic reduction but for 29% after open reduction (p = 0.005). An improvement of femoral head coverage was achieved with residual dysplasia of 23.5% after arthroscopic reduction, compared with 62% after open reduction (p = 0.002).

CONCLUSION

The arthroscopic procedure represents a meaningful alternative to the open procedure due to a lower complication rate, a safe setting, a lower rate of residual dysplasia, no observed redislocation and occurrence of osteonecrosis only once in the arthroscopic group of developmental dysplasia of the hip. The arthroscopic procedure should be tested in further studies and in other clinics in order to broaden the empirical base.

LEVEL OF EVIDENCE

Level III (retrospective cohort study).

Radiographic outcome of children older than twenty-four months with developmental dysplasia of the hip treated by closed reduction and spica cast immobilization in human position: a review of fifty-one hips

PURPOSE

This study aimed to investigate the radiographic outcomes, rate of redislocation, and avascular necrosis of proximal femoral epiphysis (AVN) in patients aged 24 to 36 months with developmental dysplasia of the hip (DDH) treated by closed reduction (CR) and spica cast immobilization in human position.

MATERIAL AND METHODS

We reviewed the medical records of 39 patients (51 hips) aged 24 to 36 months with DDH treated by CR and spica cast immobilization in human position. The Tönnis grade, rate of redislocation and AVN, acetabular index (AI), centre-edge angle (CEA), and Severin radiographic grade were evaluated on plain radiographs.

RESULTS

Among the included 39 patients (51 hips), 15 hips (29.4%) were Tönnis grade II, 24 hips (47.1%) were grade III, and 12 hips (23.5%) were grade IV. In 47 hips (92.2%), the ossific nucleus was present at the time of CR. Stable reduction was achieved by CR in 39/51 hips (76.5%) and redislocation occurred in 12/51 hips (23.5%). Among the 12 hips that redislocated, 11 underwent open reduction and one repeated CR. Two out of 40 hips (5%) treated by CR developed AVN. Overall, 54.6% of the hips had satisfactory outcomes (39.2% Severin type I and 17.6% type II), while 45.4% had unsatisfactory outcomes (39.2% Severin type III and 3.9% type IV). Of the 40 hips treated by CR, 57.5% and 42.5% of cases had satisfactory outcomes and residual acetabular dysplasia, respectively. Six out of 11 hips (54.6%) treated by open reduction and pelvic osteotomy had satisfactory outcomes.

CONCLUSIONS

Our study showed that stable CR could be achieved in 76.5% of patients aged 24 to 36 months with DDH at the time of index procedure. Satisfactory outcomes can be expected in 56.4% of the cases (5.0% AVN rate), although late acetabular dysplasia may develop in 43.6% of the hips.

Closed Reduction for Developmental Dysplasia of the Hip: Early-term Results From a Prospective, Multicenter Cohort

BACKGROUND

Closed reduction (CR) is a common treatment for infantile developmental dysplasia of the hip. The purpose of this observational, prospective, multicenter study was to determine the early outcomes following CR.

METHODS

Prospectively collected data from an international multicenter study group was analyzed for patients treated from 2010 to 2014. Baseline demographics, clinical exam, radiographic/ultrasonographic data, and history of previous orthotic treatment were assessed. At minimum 1-year follow-up, failure was defined as an IHDI grade 3 or 4 hip and/or need for open reduction. The incidence of avascular necrosis (AVN), residual dysplasia, and need for further surgery was assessed.

RESULTS

A total of 78 patients undergoing CR for 87 hips were evaluated with a median age at initial reduction of 8 months (range, 1 to 20 mo). Of these, 8 hips (9%) were unable to be closed reduced initially. At most recent follow-up (median 22 mo; range, 12 to 36 mo), 72/79 initially successful CRs (91%) remained stable. The likelihood of failure was unaffected by initial clinical reducibility of the hip (P=0.434), age at initial CR (P=0.897), or previous treatment in brace (P=0.222). Excluding those hips that failed initial CR, 18/72 hips (25%) developed AVN, and the risk of osteonecrosis was unaffected by prereduction reducibility of the hip (P=0.586), age at CR (P=0.745), presence of an ossific nucleus (P=0.496), or previous treatment in brace (P=0.662). Mean acetabular index on most recent radiographs was 25 degrees (±6 degrees), and was also unaffected by any of the above variables. During the follow-up period, 8/72 successfully closed reduced hips (11%) underwent acetabular and/or femoral osteotomy for residual dysplasia.

CONCLUSIONS

Following an initially successful CR, 9% of hips failed reduction and 25% developed radiographic AVN at early-term follow-up. History of femoral head reducibility, previous orthotic bracing, and age at CR did not correlate with success or chances of developing AVN. Further follow-up of this prospective, multicenter cohort will be necessary to establish definitive success and complication rates following CR for infantile developmental dysplasia of the hip.

LEVEL OF EVIDENCE

Level II-prospective observational cohort.

Developmental Dysplasia of the Hip

Pediatricians are often the first to identify developmental dysplasia of the hip (DDH) and direct subsequent appropriate treatment. The general treatment principle of DDH is to obtain and maintain a concentric reduction of the femoral head in the acetabulum. Achieving this goal can range from less-invasive bracing treatments to more-invasive surgical treatment depending on the age and complexity of the dysplasia. In this review, we summarize the current trends and treatment principles in the diagnosis and treatment of DDH.

Presentation and Management of Neglected Developmental Dysplasia of Hip (DDH): 8-years' experience with single stage triple procedure at National Institute of Rehabilitation Medicine, Islamabad, Pakistan

Objective:

To document the clinical presentation of neglected DDH and evaluate the outcome of triple procedure.

Methods:

It was a descriptive case series study, conducted at the Department of Orthopedic Surgery, National Institute of Rehabilitation Medicine (NIRM), Islamabad over a period of 8-years. It included children aged >1 and <9 years who underwent the triple procedure of open reduction, femoral shortening and Salter’s osteotomy. Clinical evaluation was performed using McKay’s criteria. Tonnis classification and Severin’s scoring system were employed for the radiological evaluation.

Results:

There were 193 children with 213 DDH affected hips. The mean age was 3.31±1.6 years. The preoperative severity of the femoral head dislocation per Tonnis classification was Grade-I in 7.98%(n=17), Grade-II in 48.35%(n=103) and Grade-III in 43.66%(n=93) hips. The postoperative MacKay criteria was ’Good’ to ’Excellent’ in 193(90.61%) hips. The postoperative Severin’s class was I in 113(53%) hips, II in 48(22.53%) hips, III in 43(20.18%) and IV in 9(4.22%) hips. The preoperative acetabular index ranged from 39° to 51° with a mean of 43.91±3.69°. The mean postoperative AI was 18.42±2.99°. The postoperative centre edge angle ranged from 21° to 26° with a mean 23.18 ±1.35°.

Conclusions:

The single stage triple procedure offers the surgical remedy of choice with favourable results for managing neglected and late diagnosed DDH among children aged 1-8 years.

[Treatment recommendations for protracted hip immaturity in infants : Conservative approach versus open reduction]

The healthy upright posture is a result of a continuous maturation process of the locomotor system throughout skeletal growth rendering muscle strength and stability: The hip joint in its central position plays a key role for unimpaired and pain-free gait. Nonetheless, it is also regularly affected by delayed maturation, thus being of special interest for the disease screening procedures of every newborn child. Structured screening examinations in the first 3 postnatal months will ideally detect any dysplasia, therefore simple conservative interventions will usually accelerate the maturation process. Effective hip screening programs in Austria and Germany have reduced the necessity for open surgical hip reductions to a worldwide all-time low. Perinatal risk factor awareness in doctors and parents triggers an increased sensitivity to possible immature hip structures. Nevertheless, severe hip dysplasia in toddlers is regularly presented in pediatric orthopedic centers with or without hip dislocation, mostly due to the delay of or inefficiency of treatment options. This review deals with highly effective strategies for quick treatment and provides a balanced view on conservative and surgical methods.

Duration of immobilization after developmental dysplasia of the hip and open reduction surgery

BACKGROUND

There is no consensus about the duration of post-operative immobilization in the treatment of DDH (developmental dysplasia of hip). Our aim in this study is to compare between two post-operative immobilization protocols for patients undergoing open reduction.

MATERIALS AND METHODS

Thirty-eight hips in 32 patients assigned to group A were immobilized in hip spica for four weeks followed by abduction brace application which was gradually weaned through the periods of several months and 29 hips in 24 patients assigned to group B immobilized in hip spica for 12 weeks without further bracing. Both groups were surgically reduced using anterior approach between the ages of 12-24 months.

RESULTS

There were non-significant statistical difference between both groups as regards clinical and radiological outcome but there is significant statistical difference as regards AVN (avascular necrosis) on follow-up between both groups. The rate of AVN cannot be related to the method of immobilization, as there are many factors can lead to AVN of the hip as immobilization in an extreme position and tight reduction.

CONCLUSION

Group A post-operative immobilization protocol is safer and associated with less complications and more comfortable to the patient and parents than that used in group B. Early removal of hip spica cast and application of hip abduction brace does not increase the rate of re-dislocation.

LEVEL OF EVIDENCE

Level III Retrospective comparative study.

Developmental dysplasia of the hip: an update on diagnosis and management from birth to 6 months

PURPOSE OF REVIEW

Our understanding of the epidemiology, diagnosis, and management of developmental dysplasia of the hip (DDH) is evolving. This review focuses on the most up-to-date literature on DDH in patients from birth to six months of age.

RECENT FINDINGS

Well known risk factors for DDH include family history, female sex, and breech positioning. Recent evidence suggests higher birth weight is a risk, whereas prematurity may be protective. Screening includes physical examination of all infant hips and imaging when abnormal findings or risk factors are present. Treatment in the first six months consists of a harness, with 70-95% success. Failure risk factors include femoral nerve palsy, static bracing, irreducible hips, initiation after seven weeks of age, right hip dislocation, Graf-IV hips, and male sex. Rigid bracing may be trialed if reduction with a harness fails and closed reduction is indicated after failed bracing. If the hip is still irreducible, nonconcentric, or unstable, open reduction may be required following closed reduction. Evidence does not support delaying hip reduction until the ossific nucleus is present.

SUMMARY

DDH affects 1-7% of infants. All infants should be examined and selective screening with imaging should be performed for abnormal physical exams or risk factors. Early treatment is associated with optimal outcomes.

A New Radiographic Classification System for Developmental Hip Dysplasia is Reliable and Predictive of Successful Closed Reduction and Late Pelvic Osteotomy

BACKGROUND

The Tonnis radiographic classification of developmental dysplasia of the hip (DDH) has been used as a prognostic indicator for patients with walking-age DDH. The International Hip Dysplasia Institute (IHDI) classification, a new radiographic classification system, has been proposed to be more reliable by its creators. We sought to validate its reliability using independent observers, to compare it to the Tonnis method, and to assess its prognostic significance in a large cohort of patients.

METHODS

A consecutive series of walking-age DDH patients were examined radiographically and classified by the Tonnis and IHDI schemes by 3 independent observers. Interobserver agreement was determined using the Kappa method. Clinical data were collected on patients with regard to success of closed reduction, need for later pelvic osteotomy, and presence of subsequent radiographic avascular necrosis (AVN). The prognostic value of the Tonnis and IHDI classifications to predict these clinical outcomes was determined.

RESULTS

A total of 287 hips were available for analysis of the classification schemes. In total, 235 hips underwent attempted closed reduction and were eligible for analysis of successful closed reduction, and 131 hips had >4-year follow-up and were utilized for analysis of late pelvic osteotomy and AVN. Both classifications showed excellent interobserver reliability and in general, there was nonstatistically significant better reliability for the IHDI versus the Tonnis classification. In multivariate analysis, both IHDI and Tonnis classifications were found to be predictive of successful closed reduction and need for late pelvic osteotomy. Both methods showed trends toward being predictive of AVN rate, without statistical significance.

CONCLUSIONS

The IHDI classification is subjectively more facile to use and has excellent interrelater agreement for classifying the radiographic severity of DDH. It is also reliable in predicting success of closed reduction and need for late pelvic osteotomy.

SIGNIFICANCE

practitioners and researchers should consider the IHDI classification as a useful classification scheme and prognosticator when considering treatment options for late-presenting DDH.

SIGNIFICANCE

Practitioners and researchers should consider the IHDI classification as a useful classification scheme and prognosticator when considering treatment options for late-presenting DDH.

LEVEL OF EVIDENCE

Level III.

The correlation between Salter's criteria for avascular necrosis of the femoral head and Kalamchi's prognostic classification following the treatment of developmental dysplasia of the hip

AIMS

The aim of this study was to evaluate the correlation between Salter's criteria and Kalamchi's classification of avascular necrosis in patients treated for developmental dysphasia of the hip (DDH).

PATIENTS AND METHODS

The study involved a retrospective analysis of 123 patients (123 hips) with DDH treated by operative and non-operative reduction before the age of two years, with a minimum follow-up of ten years. Salter's criteria (S1 to S4) were determined from radiographs obtained at one to two years post-reduction, whilst the Kalamchi grade was determined from radiographs obtained at ten or more years of age. Early post-reduction radiographs were also used to evaluate the centre-head distance discrepancy (CHDD) and the occurrence of a dome-shaped deformity of the proximal femoral metaphysis (D-shaped metaphysis). The prognosis was described as good (Kalamchi grade K0 or KI), fair (Kalamchi grade KII) or poor (Kalamchi grade KIII or KIV) for analysis and correlation with the early Salter criteria, CHDD and D-shaped metaphysis.

RESULTS

S1 and S2 criteria were predictive of a poor prognosis. The outcome following S3, S4 and S3 + S4 varied; 18 (40%) had a good prognosis, 17 (38%) a fair prognosis and ten (22%) a poor prognosis. A CHDD ≥ 10% and a D-shaped metaphysis were also predictive of a poor prognosis.

CONCLUSION

The Salter criteria were predictive of the Kalamchi grade of avascular necrosis in patients with DDH aged ten or more years after reduction of the hip. Cite this article: Bone Joint J 2017;99-B:1115-20.

Presence of the Ossific Nucleus and Risk of Osteonecrosis in the Treatment of Developmental Dysplasia of the Hip: A Meta-Analysis of Cohort and Case-Control Studies

BACKGROUND

Concern for increased risk of osteonecrosis in hips with an absent ossific nucleus has led some surgeons to delay reduction in the treatment of developmental dysplasia of the hip (DDH) until the ossific nucleus is present. A previous meta-analysis reported a potential protective effect against high-grade osteonecrosis (II to IV) when the ossific nucleus was present. With a greater number of publications on this topic, revisiting this analysis is warranted. The aim of this meta-analysis was to systematically review and analyze the best clinical evidence regarding the association between the status of the ossific nucleus and development of osteonecrosis following the treatment of DDH.

METHODS

MEDLINE, Embase, and Cochrane databases were systematically searched for studies including the status of the ossific nucleus and rate of osteonecrosis after open and closed reductions for the treatment of DDH. Study characteristics and risk estimates were extracted. Study quality was assessed using the Newcastle-Ottawa Scale. Pooled effect estimates were calculated using a random-effect model. Meta-regression assessed the relationships of reduction method, study quality, mean age at reduction, surgical approach, method of ossific nucleus assessment, and duration of follow-up to the odds of osteonecrosis.

RESULTS

In the 21 observational studies (18 retrospective, 3 prospective) that were included, osteonecrosis developed in 20.4% of the hips in which the ossific nucleus was present at reduction compared with 21.2% of the hips in which the ossific nucleus was absent. Presence of the ossific nucleus was not associated with decreased odds of any grade of osteonecrosis (odds ratio [OR] = 0.70, 95% confidence interval [CI] = 0.43 to 1.12) or of more severe osteonecrosis of Grades II to IV (OR = 0.70, 95% CI = 0.30 to 1.17). Meta-regression did not show any effect of the mean age at reduction, reduction method, surgical approach, study quality, minimum or mean duration of follow-up, method of ossific nucleus imaging, or osteonecrosis classification system on the relationship between presence of the ossific nucleus and the risk of osteonecrosis.

CONCLUSIONS

The current literature does not support the hypothesis that presence of the ossific nucleus at reduction is associated with lower risk of osteonecrosis. Prospective studies with long-term follow-up and blinded assessors are warranted to optimally evaluate the relationship between potential risk factors and the development of osteonecrosis.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Association between the ossific nucleus and osteonecrosis in treating developmental dysplasia of the Hip: updated meta-analysis

Background

A meta-analysis concluded that there was no effect of the femoral head ossification and the incidence of osteonecrosis in the treatment of developmental dysplasia of the hip (DDH), unless only osteonecrosis grades II-IV were considered. The meta-analysis, limited due to the small number of studies available at that time, identified a need for an update as further research emerges. We observed a trend in recent years towards delaying treatment of DDH in the absence of an ossified nucleus. Numerous new publications on this topic encouraged us to update the 2009 meta-analysis.

Methods

We performed a systematic review of the literature from 1967 to 2016 and included studies that reported on the treatment of DDH, the ossific nucleus and osteonecrosis. Two independent reviewers evaluated all articles. We performed a meta-analysis with the main outcome defined as the development of osteonecrosis of the femoral head at least two years after closed or open reduction.

Results

Of four prospective and ten retrospective studies included in the systematic review, 11 studies (1,021 hips) met the inclusion criteria for the meta-analysis. There was no significant effect of the ossific nucleus on the development of all grades of osteonecrosis (relative risk, 0.88; 95% confidence interval, 0.56–1.41) or osteonecrosis grades II–IV (0.67; 0.41–1.08). In closed reductions, the ossific nucleus halved the risk for developing osteonecrosis grades II–IV (0.50; 0.26–0.94).

Conclusions

Based on current evidence there does not appear to be a protective effect of the ossific nucleus on the development of osteonecrosis. In contrast to the previous meta-analysis, this update demonstrates that this remains the case irrespective of the grade of osteonecrosis considered relevant. This updated meta-analysis is based on twice as many studies with a higher quality of evidence.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1468-6) contains supplementary material, which is available to authorized users.

Avascular necrosis following closed reduction for treatment of developmental dysplasia of the hip: a systematic review

BACKGROUND

Avascular necrosis (AVN) is a significant and potentially devastating complication following the treatment of developmental dysplasia of the hip (DDH). The reported rate of AVN following closed reduction for DDH ranges from 4 to 60%, and the resultant influence on hip development remains unclear.

PURPOSE

A systematic review of the literature was undertaken to evaluate the frequency of AVN after more than 5 years of follow-up in children that underwent closed reduction at younger than 2-years of age for DDH.

METHODS

The search strategy was formulated with key-concepts and keywords identified using the patient problem, intervention, comparison and outcome process. Searches were undertaken using Pubmed, Scopus and Web of Science up to and including May, 2016 to identify potential studies.

RESULTS

A total of seven papers met the a priori inclusion and exclusion criteria of this review. The overall rate of significant AVN in 441 patients (538 hips) was 10% at a mean length of follow-up of 7.6 years (5-18.8) following closed reduction. This finding can be used to inform the feasibility of future intervention studies, and act as a baseline for which surgeons to compare their results to a 'standard'.

Surgical Management of Pediatric Developmental Dysplasia of the Hip

In pediatric patients with developmental dysplasia of the hip with late presentation or failure of nonsurgical treatment, surgical management is indicated. The goal of surgery is to obtain a stable reduction to promote development of the femoral head and acetabulum while avoiding osteonecrosis of the femoral head and the need for further surgery. Treatment is related to the age of the patient and the degree of soft-tissue contracture or bony deformity present. As a general rule, in children aged <12 months, closed reduction and spica casting is preferred. Children aged 12 to 18 months may require open reduction, which can be performed safely through a medial or anterior approach. In children aged 18 months to 3 years, residual bony deformity can be corrected with a femoral or pelvic osteotomy in addition to open reduction. In children with complex deformity or in children aged >3 years, both pelvic and femoral osteotomies are commonly required to stabilize an open reduction.

Risk factors for early redislocation after primary treatment of developmental dysplasia of the hip: Is there a protective influence of the ossific nucleus?

BACKGROUND

Re-dislocation after primary treatment of developmental dysplasia of the hip is a serious complication. We analyzed the various risk factors that contribute to re-dislocation, and whether the bony ossific nucleus (ON) confers increased stability against re-dislocation.

MATERIALS AND METHODS

Fifty-five children (60 hips) were classified into three treatment groups: Closed reduction (CR) in 15 children (17 hips), open reduction (OR) in 26 children (28 hips), and OR with bony surgery (ORB) in 14 children (15 hips). The mean age at initial treatment was 16 months (range 6-36 months). Fifty-one hips and 9 hips were Tonnis Grade 4 and 3, respectively. The mean preoperative acetabular index (AI) was 44.82° (range 32°-56°) for the study group. At initial treatment, bony ON was absent in 8 hips and present in 52 hips.

RESULTS

No hip developed stiffness and pain after primary treatment. Although the AI index, Tonnis grade, and absence of ossific nucleus were higher in the re-dislocated groups, this was not statistically significant. Excluding the re-dislocations, four children had a fair outcome, 11 had good outcome, and 36 had excellent outcome as per McKay's criteria. In the CR group (17 hips), two children (2 hips) with absent ON had re-dislocation. In the OR group (28 hips), three re-dislocations were seen (three children) at 3, 5, and 7 months, respectively. Two of these had an absent bony ON. In the ORB group (15 hips), one late sub-luxation occurred in a child with absent ON. The mean preoperative AI for the re-dislocated and located group was 44.66° (range 42°-48°) and 44.53° (range 39°-56°), respectively. The postoperative AI was 34.53.

CONCLUSION

The experience of the treating surgeon and technical factors play an overwhelming role in preventing early dislocation. The absence of ON should perhaps alert the surgeon for enhanced spica care, postoperative splinting, and meticulous intra-operative management.

Association between open or closed reduction and avascular necrosis in developmental dysplasia of the hip: A PRISMA-compliant meta-analysis of observational studies

BACKGROUND

The risk of avascular necrosis of the femoral head (AVN) after treatment of developmental dysplasia of the hip is associated with the method of reduction. Some authors have suggested that open reduction is a risk factor for AVN; however, this is controversial. To our knowledge, a quantitative comparison of the incidence of AVN between closed and open reduction has not been conducted.

METHODS

Published studies were identified by searching PubMed, EMBASE, and the Cochrane Library up to May, 2015, focusing on the incidence of AVN after closed or open reduction for developmental dysplasia of the hip in children aged <3 years. Patients were age-matched who were treated by either closed or open reduction, but without pelvic or femoral osteotomy. Two authors independently assessed eligibility and abstracted data. Discrepancies were discussed and resolved by consensus. We pooled the odds ratios (ORs) and 95% confidence intervals (95%CIs) from individual studies using a random-effects model and evaluated heterogeneity and publication bias.

RESULTS

Nine retrospective studies were included in this analysis. The pooled OR for comparing open reduction with closed reduction for all grades of AVN was 2.26 (95%CI = 1.21-4.22), with moderate heterogeneity (I = 44.7%, P = 0.107). The pooled OR for grades II to IV AVN was 2.46 (95%CI = 0.93-6.51), with high heterogeneity (I = 69.6%, P = 0.003). A significant association was also found for the further surgery between open and closed reduction, with a pooled OR of 0.30 (95%CI = 0.15-0.60) and moderate heterogeneity (I = 46.4%, P = 0.133). No evidence of publication bias or significant heterogeneity between subgroups was detected by meta-regression analyses.

CONCLUSION

Findings from this meta-analysis suggest that open reduction is a risk factor for the development of AVN compared with closed treatment. Future studies are warranted to investigate how open reduction combined with pelvis and/or femoral osteotomy affects the incidence of AVN.

Risk factors for avascular necrosis after closed reduction for developmental dysplasia of the hip

PURPOSE

The purpose of this study was to identify and evaluate risk factors of avascular necrosis (AVN) after closed treatment for developmental dysplasia of the hip (DDH).

METHODS

A retrospective review of children diagnosed with DDH at a tertiary-care children's hospital between 1986 and 2009 was performed. The presence of AVN was assessed according to Salter's classification system.

RESULTS

Eighty-two affected hips in 70 children with an average age of 10 months at closed reduction (range 1-31 months) and 5 years (range 2-19 years) of follow-up met the inclusion criteria. Twenty-nine (of 82, 35 %) affected hips developed AVN. The use of pre-reduction traction (p = 0.019) increased the risk of AVN, while preoperative Pavlik harness or brace trial (p = 0.28), presence of ossific nucleus at the time of closed reduction (p = 0.16), and adductor tenotomy (p = 0.37) were not significant factors. Laterality (right vs. left) was also not a significant risk factor (p = 0.75), but patients who underwent closed reduction for bilateral DDH were less likely to develop AVN (p = 0.027). Overall, the degree of abduction did not affect the rate of AVN (p = 0.87). However, in patients treated with closed reduction younger than 6 months of age, the rate of AVN was increased with abduction ≥50° (9/15, 60 %) compared to abduction <50° (0/8, 0 %) (p = 0.007). Patients who developed AVN were more likely to require subsequent surgery (p = 0.034) and more likely to report a fair/poor clinical outcome (p = 0.049).

CONCLUSIONS

The risk of AVN (35 %) following closed reduction and spica casting for DDH is high. The degree of abduction in spica casts appears to be a risk factor in patients ≤6 months old. The authors recommend that abduction in spica casts should be limited to <50° in children younger than 6 months of age.

LEVEL OF EVIDENCE

IV.

Is Age or Surgical Approach Associated With Osteonecrosis in Patients With Developmental Dysplasia of the Hip? A Meta-analysis

BACKGROUND

Osteonecrosis of the femoral head is a major complication that negatively impacts the clinical and radiographic long-term outcome after treatment of developmental hip dysplasia (DDH). There are conflicting results in the literature whether age at the time of closed or open reduction and a specific surgical approach are associated with osteonecrosis. Better understanding of the impact of age at reduction and surgical approach is important to reduce the risk of osteonecrosis in patients with DDH.

QUESTIONS/PURPOSES

We aimed to evaluate the association between occurrence of osteonecrosis and (1) age at closed reduction; (2) age at open reduction; and (3) medial versus anterior operative approaches.

METHODS

A systematic review identified studies reporting osteonecrosis occurrence after treatment of DDH and at least 2 years of followup. This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Methodologic quality was assessed using the methodologic index for nonrandomized studies. Generalized logistic models were used to estimate pooled odds ratios (ORs) in the meta-analysis. Sixty-six studies were included in the systematic review and 24 in the meta-analysis. Data on 481 hips treated by closed reduction and 584 hips treated by open reduction were available to evaluate the association between osteonecrosis and age. The association between osteonecrosis and operative approach was assessed using data on 364 hips treated by medial open reduction and 220 hips treated by anterior open reduction.

RESULTS

Age at reduction (> 12 months versus ≤ 12 months) was not associated with osteonecrosis after closed reduction (OR, 1.1; 95% confidence interval [CI], 0.4-3.2; p = 0.9) or open reduction (OR, 1.1; 95% CI, 0.7-1.9; p = 0.66). The overall, adjusted incidence of osteonecrosis (≥ Grade II) was 8.0% (95% CI, 2.8%-20.6%) among patients treated with closed reduction at or before 12 months of age and 8.4% (95% CI, 3.0%-21.5%) among those treated after 12 months. Similarly, the odds of osteonecrosis after open reduction did not differ between patients treated after the age of 12 months compared with those treated at or before 12 months (OR, 1.1; 95% CI, 0.7-1.9; p = 0.7). The incidence of osteonecrosis (≥ Grade II) was 18.3% (95% CI, 11.7%-27.4%) among patients who had index open reduction at or before 12 months of age and 20.0% (95% CI, 13.1%-29.4%) among those who had index open reduction after 12 months of age. Among hips treated with open reductions, there was no difference in osteonecrosis after medial versus anterior approaches (18.7% medial versus 19.6% anterior; OR, 1.1; 95% CI, 0.5-2.2; p = 0.9). Conclusions We did not find an association between closed or open reduction performed at or before 12 months of age and an increased risk of osteonecrosis of the femoral head. Delayed treatment past 1 year of age as a strategy to reduce the development of osteonecrosis was not supported by this meta-analysis. Open reduction through a medial or anterior approach may be recommended based on surgeon's preference, because we found no association between development of osteonecrosis and the type of surgical approach. However, many of the studies in the current literature are nonrandomized Level III or IV observational studies of inconsistent quality. Higher quality evidence is needed to better understand the effects of age at reduction and operative approach on the development of osteonecrosis after DDH treatment.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Acetabuloplasties at Open Reduction Prevent Acetabular Dysplasia in Intentionally Delayed Developmental Dysplasia of the Hip: A Case-control Study

BACKGROUND

Avascular necrosis (AVN) and residual acetabular dysplasia are the two main complications of developmental dysplasia of the hip (DDH) treatment. Although early reduction of the hip may decrease the incidence of residual dysplasia, it may increase the incidence of AVN and vice versa. However, we do not know if changes in surgical technique may lead to a modification in these outcomes.

QUESTIONS/PURPOSES

Does an incomplete periacetabular acetabuloplasty, as an added step to delayed open reduction, (1) diminish the risk of developing acetabular dysplasia; or (2) increase the rate of AVN compared with patients treated with open reduction alone?

METHODS

We conducted a retrospective matched case-control study comparing 22 patients (27 hips) with early isolated DDH who underwent intentionally delayed open reduction and acetabuloplasty from 2004 to 2010 and followed up > 4 years (88% of the cohort) with early historic controls treated with delayed open reduction alone. Of 53 patients available for matching, 45 (85%) had enough followup (> 10 years) to be considered. They were matched one to one for age at presentation and bilaterality (fuzz 45, 0). This generated a control group of 25 patients (27 hips). The mean followup was different between the groups (p < 0.001). Residual dysplasia considered when center-edge angle < 15° (6-13 years old) or < 20° (≥ 14 years old) or as a nonevolving acetabular index > 30° and pelvic osteotomies were used as our primary outcomes. The proportion of patients with AVN was also compared.

RESULTS

Patients treated with open reduction and an incomplete periacetabular acetabuloplasty were less likely to develop acetabular dysplasia and undergo pelvic osteotomies than were patients in the control group (0% [zero of 27] versus 37% [10 of 27]; odds ratio [OR], 11; 95% confidence interval [CI], 2-80; p = 0.02 and 0% [zero of 27] versus 26% [seven of 27]; OR, 8; 95% CI, 1-60; p = 0.025, respectively). With the available numbers, there was no difference in terms of the proportion of patients who developed AVN (11 of 27 [41%] both groups; OR, 1; 95% CI, 1-2; p = 1).

CONCLUSIONS

The addition of an incomplete periacetabular acetabuloplasty to all hips undergoing open reduction eliminated residual acetabular dysplasia, whereas it did not appear to have deleterious effects as evidenced by the similar AVN proportion.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Does Perfusion MRI After Closed Reduction of Developmental Dysplasia of the Hip Reduce the Incidence of Avascular Necrosis?

BACKGROUND

Gadolinium-enhanced perfusion MRI (pMRI) after closed reduction/spica casting for developmental dysplasia of the hip (DDH) has been suggested as a potential means to identify and avoid avascular necrosis (AVN). To date, however, no study has evaluated the effectiveness of pMRI in clinical practice or compared it with other approaches (such as postreduction CT scan) to show a difference in the proportion of AVN.

QUESTIONS/PURPOSES

(1) Can a pMRI-based protocol be used immediately post closed reduction to minimize the risk that AVN would develop? (2) What are the overall hip-related outcomes after closed reduction/spica casting using this protocol? (3) Do any patient-specific factors at the time of closed reduction predict future AVN?

METHODS

This was a retrospective cohort study at a large tertiary care children's hospital. Between 2009 and 2013 we treated 43 patients with closed reduction/spica casting for DDH, of whom 33 (77%) received a postreduction pMRI. All patients were indicated for pMRI per treating surgeon preference. A convenience sample totaling 25 hips in 22 patients treated with pMRI was then established using the following exclusion criteria: DDH of neuromuscular/syndromic origin, failed initial closed reduction, less than 1 year of clinical and radiographic followup, and subsequent open reduction. Next, the 40 patients treated with closed reduction between 2004 and 2009 were screened until the chronologically most recent 25 hips (after applying the previously mentioned exclusion criteria) were identified in 21 of the first 34 patients (62%) screened. Although termed the CT group, specific postreduction imaging was not a defined inclusion criterion in this group with the majority (21 of 25 [84%]) receiving postreduction CT and the remainder (four of 25 [16%]) receiving only postreduction radiographs. All hips with globally decreased femoral head perfusion on postreduction pMRI were treated with immediate cast removal followed by repeat closed reduction or open reduction, as per surgeon preference, with two of 33 (6%) requiring such further interventions. Salter criteria were then used to determine the proportion of AVN on radiographs at 1-year and final followup. Secondary outcomes including residual dysplasia and the need for further corrective surgery were ascertained through radiographic and retrospective chart review.

RESULTS

At 1-year followup there was no difference in the proportion of AVN in the historical CT group as compared with the pMRI group (six of 25 [24%] versus one of 25 [4%]; odds ratio [OR], 7.6; 95% confidence interval [CI], 0.8-363; p = 0.098). However, by final followup there was a statistically higher proportion of AVN in the CT group (seven of 25 [28%] versus one of 25 [4%]; OR, 9.3; 95% CI, 1.0-438; p = 0.049). No patient with normal perfusion on postreduction pMRI went on to develop AVN. In those pMRI patients in whom a successful reduction was initially obtained, two of 25 (8%) went on to require further corrective surgery and one of 25 (4%) had a redislocation event. With the numbers available, no patient-specific factors at the time of closed reduction were predictive of future AVN, including the patient's age/weight, the presence of an ossific nucleus, history of previous bracing treatment, or the abduction angle in spica cast.

CONCLUSIONS

A pMRI-based protocol immediately after closed reduction/spica casting may decrease the risk of AVN by helping the surgeon to evaluate femoral head vascularity. Although preliminary in nature, this study could serve to guide further investigation into the potential role of pMRI for the treatment of patients who require closed reduction/spica casting for DDH.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Adverse Outcomes in Infantile Bilateral Developmental Dysplasia of the Hip

BACKGROUND

It is believed that bilateral developmental dysplasia of the hip (DDH) has poorer outcomes with higher rates of avascular necrosis (AVN) and reintervention, compared with unilateral DDH. However, there is limited evidence in the literature, with few studies looking specifically at bilateral cases.

METHODS

A retrospective review of 36 patients (72 hips) with >4 years of follow-up. Patient population included surgically treated DDH including late presentations and failures of conservative treatment. The dislocated hips underwent either simultaneous closed or 1 open and 1 closed, or sequential open reduction. AVN and secondary procedures were used as endpoints for analysis as well as clinical and radiologic outcomes.

RESULTS

At the last follow-up, 33% of hips had radiologic signs of AVN. Those hips that had no ossific nucleus (ON) at the time of surgery had an odds ratio of developing AVN of 3.05 and a statistically significant association between the 2 variables, whereas open/closed or simultaneous/sequential reduction did not increase the risk for AVN. In addition, 45.8% of those hips required further surgery. The estimated odds ratio of needing additional surgery after simultaneous reduction was 4.04. Clinically, 79.2% of the hips were graded as McKay I, whereas radiologically only 38.8% were Severin I.

CONCLUSIONS

The AVN rate in bilateral DDH treated surgically is greater than the rate noted in unilateral cases from the same institution undergoing identical protocols. There was no difference in AVN rates between simultaneous and sequential or between the first and second hip to be sequentially reduced. Presence of ON decreases the risk for AVN, suggesting that in bilateral cases, awaiting the appearance of the ON is an important tool to reduce the incidence of AVN.

LEVEL OF EVIDENCE

IV.

A review of long-term outcomes for late presenting developmental hip dysplasia

Successful management of late presenting hip dislocation in childhood is judged by the outcome not just at skeletal maturity but well beyond into adulthood and late middle age. This review considers different methods of treatment and looks critically at the handful of studies reporting long-term follow-up after successful reduction.

Developmental Dislocation of the Hip Successfully Treated by Preoperative Traction and Medial Open Reduction: A 22-year Mean Followup

BACKGROUND

During the last 35 years, the medial approach has been reported more frequently than the anterior approach for open reduction of developmental dislocation of the hip (DDH), however, few studies have followed children treated by medial open reduction to adulthood.

QUESTIONS/PURPOSES

The purposes of our study were: (1) to assess the development of 71 completely dislocated hips after medial open reduction, the incidence of additional surgery and avascular necrosis during the followup period, and the long-term radiographic and functional results; and (2) to compare our results with those obtained by others who performed open reduction either by the medial or anterior approach.

PATIENTS AND METHODS

We retrospectively evaluated, after the end of growth, 71 hips in 52 patients who underwent open reduction by the medial approach. The mean age of the patients was 16 months (range, 3-36 months). After surgery, the hips were immobilized in 100° flexion, 60° abduction, and neutral rotation for an average of 6 months. All patients had staged clinical and radiographic followups until skeletal maturity. The length of followup averaged 22 years (range, 13-32 years).

RESULTS

In all the surgically treated hips, the acetabular index normalized by the end of growth, the incidence of avascular necrosis was 18%, and additional surgery was required in 15% of our cases. At the last followup, 93% of the hips were classified as Severin Classes I or II and 7% as Class III; 76% of the hips had an excellent result, 17% had a good result, and 7% had a fair result according to the McKay scale as modified by Barrett and colleagues.

CONCLUSIONS

Open reduction of DDH through a medial approach provided good long-term radiographic and functional results in patients 3 to 36 months old and it was the only surgery performed in 85% of our cases. Future comparative studies are needed to confirm our results, especially in older children.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Failed Pavlik harness treatment for DDH as a risk factor for avascular necrosis

BACKGROUND

Avascular necrosis (AVN) of the femoral head is an irreversible complication seen in the treatment of developmental dysplasia of hip (DDH) with the Pavlik harness. Its incidence is reported to be low after successful reduction of the hip but high if the hip is not concentrically relocated. We aim to investigate its incidence after failed Pavlik harness treatment.

METHODS

We prospectively followed up a group of children who failed Pavlik harness treatment for DDH treated at our institution by the senior author between 1988 and 2001 and compared their rates of AVN with a group of children who presented late and hence were treated surgically. AVN was graded as described by Kalamchi and MacEwen and only grade 2 to 4 AVN was considered significant and included in the analysis.

RESULTS

Thirty-seven hips were included in the failed Pavlik group (group 1) and 86 hips in the no Pavlik group (group 2). Ten hips in group 1 developed AVN (27%), whereas only 7 hips in group 2 (8%) developed AVN; the odds of developing AVN after failed Pavlik treatment was 4.7 (95% confidence interval, 1.3-14.1) (P=0.009) with a relative risk of 3.32 (range, 1.37 to 8.05).

CONCLUSIONS

There was no statistically significant association observed with duration of splintage and severity of AVN (Spearman's correlation, -0.46; P=0.18). However, there was a positive correlation noted with age at presentation and severity of AVN. Therefore, we advise close monitoring of hips in the Pavlik harness and discontinue its use if the hips are not reduced within 3 weeks.

LEVEL OF EVIDENCE

Level III.

Medial versus anterior open reduction for developmental hip dislocation in age-matched patients

BACKGROUND

The difference between medial (MAOR) and anterior (AAOR) approaches for open reduction of developmental hip dysplasia in terms of risk for avascular necrosis (AVN) and need for further corrective surgery (FCS, femoral and/or acetabular osteotomy) is unclear. This study compared age-matched cohorts undergoing either MAOR or AAOR in terms of these 2 primary outcomes. Prognostic impact of presence of ossific nucleus at time of open reduction was also investigated.

METHODS

Institutional review board approval was obtained. Nineteen hips (14 patients) managed by MAOR were matched with 19 hips (18 patients) managed by AAOR based on age at operation (mean 6.0; range, 1.4 to 14.9 mo). Patients with neuromuscular conditions and known connective tissue disorders were excluded. Primary outcomes assessed at minimum 2 years' follow-up included radiographic evidence of AVN (Kalamchi and MacEwen) or requiring FCS.

RESULTS

MAOR and AAOR cohorts were similar regarding age at open reduction, sex, laterality, and follow-up duration. One hip in each group had AVN before open reduction thus were excluded from AVN analysis. At minimum 2 years postoperatively (mean 6.2; range, 1.8 to 11.7 y), 4/18 (22%) MAOR and 5/18 (28%) AAOR met the same criteria for AVN (P=1.0). No predictors of AVN could be identified by regression analysis. Presence of an ossific nucleus preoperatively was not a protective factor from AVN (P=0.27). FCS was required in 4/19 (21%) MAOR and 7/19 (37%) AAOR hips (P=0.48). However, 7/12 (54%) hips failing closed reduction required FCS compared with 4/26 (16%) hips without prior failed closed reduction (P=0.024). Cox regression analysis showed that patients who failed closed reduction had an annual risk of requiring FCS approximately 6 times that of patients without a history of failed closed reduction (hazard ratio=6.1; 95% CI, 1.5-24.4; P=0.009), independent of surgical approach (P=0.55) or length of follow-up (P=0.78).

CONCLUSIONS

In this study of age-matched patients undergoing either MAOR or AAOR, we found no association between surgical approach and risk of AVN or FCS. In addition, we identified no protective benefit of a preoperative ossific nucleus in terms of development of AVN. However, failing closed reduction was associated with a 6-fold increased annual risk of requiring FCS.

SIGNIFICANCE

To the best of our knowledge, this is the first study comparing these 2 surgical techniques in an age-matched manner. It further corroborates previous studies stating that there may be no difference in risk of AVN based on surgical approach or presence of ossific nucleus preoperatively.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Treatment and prevention of hip dysplasia in infants and young children

The diagnosis and treatment of developmental dysplasia of the hip in the infant are uniform, with consensus that diagnostic ultrasound and Pavlik harness management are standard procedures. Sequential procedures for failed early treatment, residual dysplasia and late diagnosis are dependent on the age and the severity of the dysplasia. This paper reviews the treatment of developmental dysplasia of the hip from birth to subsequent follow-up procedures, with particular reference to some of the senior authors' research and the Southampton approach to the management of hip dysplasia.

Evidence-based management of developmental dysplasia of the hip

Developmental Dysplasia of the Hip (DDH) refers to a spectrum of abnormalities involving the developing hip. These abnormalities range from mild instability to frank dislocation of the joint. It is important to treat the condition effectively in order to encourage the hip to develop normally and produce good long-term results. This article reviews the evidence related to the treatment of DDH. The quality of evidence for DDH management remains low, with little uniformity in terminology and most studies being retrospective in nature. Given this, it is not possible to recommend or reject most treatment modalities based on existing studies.

Incomplete periacetabular acetabuloplasty

BACKGROUND

Residual acetabular dysplasia is one of the most common complications after treatment for developmental dysplasia of the hip. The acetabular growth response after reduction of a dislocated hip varies. The options are to wait and add a redirectional osteotomy as a secondary procedure at an older age, or to perform a primary acetabuloplasty at the time of the open reduction to stimulate acetabular development. We present the early results of such a procedure-open reduction and an incomplete periacetabular acetabuloplasty-as a one-stop procedure for developmental dysplasia of the hip.

PATIENTS AND METHODS

We retrospectively reviewed the results obtained with 55 hips (in 48 patients, 43 of them girls) treated between September 2004 and February 2011. This cohort included late presentations and failures of nonoperative treatment and excluded unsuccessful previous surgical treatment (including closed reductions), neuromuscular disease, and other teratological conditions. Patients were treated once the ossific nucleus was present or when they reached one year of age. 31 cases were late presentations while 17 represented failures of nonoperative treatment. The mean age of the patients at surgery was 1.3 (0.6-2.6) years. The mean follow-up period was 4 (2-8) years. According to the IHDI classification, 1 was grade I, 9 were grade II, 13 were grade III, and 32 were grade IV. Results The mean acetabular index fell from 38 (23-49) preoperatively to 21 (10-27) at the last follow-up. There were no infections, nerve palsies, or graft extrusions. None of the cases required secondary surgery for residual acetabular dysplasia. 8 patients developed avascular necrosis (AVN) of grade II or more. The incidence of AVN was significantly associated with previous, failed nonoperative treatment. 1 patient developed coxa magna requiring shelf arthroplasty 4 years after the index procedure and 1 patient with lateral growth arrest required medial screw epiphysiodesis.

INTERPRETATION

This incomplete periacetabular acetabuloplasty is a reliable adjunct to open reductions, and it is followed by a rapid acetabular growth response that avoids secondary pelvic procedures. It is a one-stop surgery with predictable outcome that can be performed in 0.5- to 2.5-year-old children.

Open reduction for developmental dysplasia of the hip: failures of screening or failures of treatment?

INTRODUCTION

The aim of this study was to define the clinical indications and demographic characteristics of patients under-going open reduction for developmental dysplasia of the hip (DDH), and determine the proportion due to preventable failures of contemporary clinical screening and early management.

METHODS

Case notes were reviewed of consecutive primary open reductions performed for non-teratologic hip dislocation at the Great Ormond Street Hospital for Children over a five-year period. Forty-eight patients (64 hips) were suitable for inclusion. A telephone survey confirmed selective hip ultrasonography screening protocols were employed in all maternity hospitals in our referral base.

RESULTS

There were no cases of open reduction for unilateral DDH following Pavlik treatment commenced by six weeks of age, highlighting the importance of early detection and treatment. Eleven cases (23%) may have been avoided by appropriate implementation of existing selective ultrasonography screening protocols. Thirty-four cases (71%) presented after four months of age, suggesting open reduction is associated with late diagnosis rather than failure of primary management. None of these patients had neonatal hip ultrasonography and only 12% (4 patients) had a risk factor that should have triggered a scan.

CONCLUSIONS

Compared with published results, the contemporary screening practices in our referral base are failing to eliminate late presenting DDH and the need for open surgical reduction. Changes in strategy and implementation are required to significantly improve screening efficacy.