Adverse Outcomes in Infantile Bilateral Developmental Dysplasia of the Hip

Association between ossific nucleus volume changes and postoperative avascular necrosis risk in children with developmental dysplasia of the hip

This study aimed to investigate the correlation between ossific nucleus volume and avascular necrosis (AVN) in pediatric patients diagnosed with developmental dysplasia of the hip (DDH). Analyzing 211 cases, including 119 open reduction (OR) and 92 closed reduction (CR) procedures, we quantified ossific nucleus volume using magnetic resonance imaging (MRI). Categorizing the OR group based on ossific nucleus volume revealed no statistically significant difference in AVN incidence. Similarly, in the CR cohort, there was no significant discrepancy in AVN occurrence between subgroups with or without the ossific nucleus. Logistic regression in CR identified the international hip dysplasia institute (IHDI) grade as a significant AVN risk factor (p = 0.007). IHDI grades 3 and 4 exhibited a 6.94 times higher likelihood of AVN compared to grades 1 and 2. Across CR and OR, neither initial age nor ossific nucleus volume emerged as AVN risk factors. In conclusion, ossific nucleus volume does not pose a risk for AVN in DDH children undergoing CR or OR, emphasizing the clinical significance of IHDI grading in predicting AVN risk during CR and the importance of early intervention to prevent treatment delays.

Bilateral Involvement in Developmental Dislocation of the Hip: Analysis of 561 Patients Operated on Using the Limited Posteromedial Approach

Our objective was to scrutinize the risk factors related to bilateral involvement in the developmental dysplasia of the hip (DDH) and to inspect the impact of bilaterality on the enduring results of the DDH. All patients, aged between 6 and 18 months, who underwent surgery using the limited posteromedial approach (734 hips from 561 patients), were included in this study. The number of births, birth type, history of consanguineous marriage, family history, and swaddling were analyzed. Physical examination and complaints of the patients were evaluated, and direct radiographs were examined in terms of the redislocation, avascular necrosis, and residual acetabular dysplasia. Among the 561 patients, bilateral DDH was observed in 173 patients (30.8%). The use of swaddling was found to be statistically significant between groups (p = 0.012). The use of swaddling for more than one month was associated with a higher odds ratio for bilaterality (p = 0.001, OR = 1.56, 95% CI: 1.2-2.0). Furthermore, bilaterality was associated with a higher risk for redislocation in DDH (p = 0.001, OR = 4.25, 95% CI: 1.6-11.2). The study concludes that swaddling for over a month is strongly linked with the bilateral involvement in DDH. It is important to note that bilaterality plays a crucial role in the development of redislocation after open reduction in DDH.

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.

Teardrop and sourcil line (TSL): a novel radiographic sign that predicts residual acetabular dysplasia (RAD) in DDH after closed reduction

BACKGROUND

Residual acetabular dysplasia (RAD) is a major problem of developmental dysplasia of the hip (DDH) after closed reduction (CR). Several parameters have been investigated as ways of predicting RAD; however, prediction of RAD remains controversial. The purpose of this study was to evaluate the radiographic sign of teardrop and sourcil line (TSL) in pediatric patients with DDH to enable prediction of RAD after CR.

METHODS

One hundred and twenty-five hips with DDH treated with CR and followed up for at least 2 years were included in this study. The mean age at CR was 18.3 months (range, 9 to 32 months) and the average follow-up time was 50.2 months (range, 24 to 89 months). The acetabular index (AI) was measured at different time points. The cases were divided into two groups according to whether TSL became continuous or not. The relationships among TSL, AI and RAD were analyzed.

RESULTS

The RAD incidence was 73.6% (92/125) at the last follow-up. AI at CR and TSL were the prognostic factors for RAD (P=0.017 and 0.001, respectively). Thirty-four hips showed a continuous TSL. There was a lower RAD rate in the TSL continuous group (P<0.001). There was no statistical difference in the AI at CR between the TSL continuous and discontinuous groups; however, the level of AI after CR was lower in the TSL continuous group. The TSL of 74% (20/27) hips became continuous after acetabular osteotomy surgery.

CONCLUSIONS

The TSL continuous group had a lower AI and incidence of RAD than the discontinuous group. The TSL can be a predictive factor of RAD in DDH after CR and restore the continuous of TSL maybe a potential parameter that can help surgeons to make a judgment intra-operation.

Simultaneous versus staged surgeries for the treatment of bilateral developmental hip dysplasia in walking age: A comparison of complications and outcomes

OBJECTIVES

This study aims to compare the radiological outcomes and rate of complication between single-stage and staged operation for the treatment of bilateral developmental dysplasia of the hip (DDH).

PATIENTS AND METHODS

A total of 100 patients (13 males, 87 females; mean age: 18.1±2.1 months; range, 12 to 36 months) with bilateral DDH who were older than 15 months of age and treated with open reduction (OR) or Pemberton pericapsular osteotomy (PPO) were retrospectively analyzed. Of the patients, 48 were operated with OR and 52 were operated with PPO. Improvements in acetabular indices, presence of avascular necrosis, radiological results, and other complications were noted.

RESULTS

There was no statistically significant difference in the preoperative acetabular indices, range of International Hip Dysplasia Institute (IHDI) classification, follow-up period, and age at the time of operation between the groups (p>0.05). There was no statistically significant difference in the acetabular indices, rate of avascular necrosis, and radiological results at the end of 24 months of follow-up between the groups (p>0.05).

CONCLUSION

Our study results show no significant difference in the radiological outcomes and complications between simultaneous and staged surgeries for the treatment of bilateral DDH in children in the walking age.

Efficacy of closed reduction for developmental dysplasia of the hip: midterm outcomes and risk factors associated with treatment failure and avascular necrosis

BACKGROUND

The purpose of this study was to evaluate the efficacy of closed reduction (CR) in the treatment of developmental dysplasia of the hip (DDH) and to investigate risk factors associated with CR failure and avascular necrosis (AVN) occurrence in follow-ups.

METHODS

The study retrospectively included 110 patients and 138 hips with DDH diagnosis that underwent closed reduction between February 2012 and November 2015 in our single tertiary medical institution. The failure rate of CR and the underlying risk factors were evaluated. Meanwhile, the incidence of AVN and the related risk factors among the successful CR cases were assessed.

RESULTS

The overall failure rate of DDH treated by CR in the present study was 31.16% (43/138). Risk factors for the CR failure were older age at the time of CR (≥ 18.35 month), large medical interval before CR (≥ 35.35 mm), and severer dislocation of the affected hip (IDHI grades III and IV). The incidence of AVN was 8.33% (6/72) in patients with successful CR at the last follow-up. No significant risk factors had been established in the present study that associated with the AVN occurrence.

CONCLUSIONS

For the treatment of DDH with CR, patients with younger age might achieve better outcomes; early diagnosis and early treatment might be the key point in the DDH treatment.

Timing for closed reduction procedure for developmental dysplasia of the hip and its failure analysis

Background

It remains controversial whether the older age to perform closed reduction (CR) procedure for developmental dysplasia of the hip (DDH), the higher incidence of complications. The aim of this study is to evaluate the midterm outcome of CR for DDH among different age groups, and to analyze and identify risk factors for the failure of this procedure.

Methods

Clinical data of 107 DDH patients, who received CR, were retrospectively reviewed. Data were divided into three groups according to initial treatment age (Group I: younger than 12 months; Group II: 12 months to less or equal to18 months; Group III: older than 18 months). The presence of avascular necrosis (AVN), residual acetabular dysplasia (RAD), re-dislocation, and further surgeries (FS) were observed. The risk factors were identified for those outcomes aforementioned using univariable logistic regression models. For identified risk factor age, pre-op acetabular index (AI) and post-op AI, their prediction of CR failure were evaluated by receiver operating characteristics curve (ROC).

Results

A total of 107 patients (156 hips) undergoing CR procedure were evaluated with a median age at initial reduction of 13.0 ± 5.4 months (range, 4 to 28 mo). Mean follow-up time in this study was 6.7 ± 0.8 years (range, 3–8 years). The incidence of AVN, RAD and re-dislocation was 15.4% (24/156), 17.3% (27/156) and 14.7% (23/156) respectively. For AVN, RAD and re-dislocation, the significant risk factors are pre-op IHDI IV (p = 0.033), age ≥ 18 months (p = 0.012), and pre-op IHDI IV (p = 0.004) and walking (p = 0.011), respectively. The areas under the ROC curve of each type of failures were 0.841 (post-op AI), 0.688 (pre-op AI) and 0.650 (age).

Conclusions

Severe DDH patients older than 18 months with CR procedure may result in a high risk of RAD complication. Re-dislocation is significantly associated with pre-op IHDI IV and walking. Patients, who are older than 12.5 months or have a pre-op AI of 38.7° or a post-op AI of 26.4°, are also more likely to fail of CR procedure.

Developmental Dysplasia of the Hip with Concurrent Legg-Calvé-Perthes Disease in the Contralateral Hip

Developmental dysplasia of the hip (DDH) is a common hip disorder in pediatrics; about one in 100 newborns has it due to dysplasia and one to two per 1000 have it due to dislocation. Some factors are responsible for the disease, and breech presentation has been identified as a major risk factor. It might be associated with other conditions too. Patients with Legg-Calvé-Perthes disease present with painless limping gait with idiopathic etiology; it is unilateral in most of the cases. This paper reported a rare scenario of DDH associated with concurrent contralateral Legg-Calvé-Perthes disease.

A 5-year-old Saudi male patient, known case of developmental dysplasia of the right hip, which was managed operatively at a different hospital, presented in our outpatients clinic for right hip dysplasia and was found incidentally as having a limping gait due to left hip limited range of motion, following clinical assessment, pelvic radiographs demonstrated presence of subluxation at the right hip in addition to sclerosis, and irregularity of the left femoral head epiphysis. Right pelvic Dega osteotomy, femoral derotation osteotomy, varus osteotomy, and left hip arthrogram was examined under anesthesia with the positioning of the left hip at 45 degrees of abduction and 30 degrees of flexion to achieve the best coverage. Hip spica application was performed to correct DDH of the right hip. Repeated radiography at the subsequent visits showed better coverage of the femoral head on the right side. During a routine follow-up, there were also some osteonecrotic changes of the left femoral head that confirmed the diagnosis of left Legg-Calvé-Perthes disease.

Sequential one-stage combined procedure for treating bilateral developmental hip dysplasia after walking age

Objective

This study aimed to evaluate outcomes of the sequential one-stage combined procedure for treating bilateral developmental dysplasia of the hip (DDH) that was diagnosed after walking age.

Methods

Thirty-five patients (70 hips) with late-presenting bilateral DDH were treated with the sequential one-stage combined procedure. Hips were reclassified according to the operative time and divided into the first and the second operated hips. The outcomes were compared clinically and radiographically between the two sides preoperatively and postoperatively.

Results

The mean interval time between the two procedures was 5.9 months (range: 2–9 months). The first operated hip achieved better results than did the second operated hip. A total of 68.6% (24/35) of the patients in our series had an asymmetric outcome.

Conclusions

The sequential one-stage combined procedure is a challenge, but a reasonable alternative surgery for bilateral DDH in children after walking age. An asymmetric outcome is a special complication of this procedure.

Bilateral Developmental Dysplasia of the Hip: Does Closed Reduction Have a Role in Management? Outcome of Closed and Open Reduction in 92 Hips

BACKGROUND

Bilateral developmental dysplasia of the hip (DDH) is believed to have a worse outcome than unilateral DDH with the optimal treatment unclear. To define indications for treatment we report a retrospective series of 92 hips (46 patients) who underwent closed reduction (CR) and/or open reduction (OR).

METHODS

A total of 58 hips in 29 patients underwent attempted CR using our standardized protocol. In the same 12 year time period, 54 hips in 27 patients underwent an OR. Outcome measures included resolution of acetabular dysplasia, need for further surgery, development of osteonecrosis (ON), and modified Severin Grade.

RESULTS

CR was successful in 57% of hips; in this group secondary surgery was required in 15% and ON was seen in 12%. In the OR group, 11% failed to stabilize and required further early surgery: ON rate was 15% overall, and secondary surgery was required in 5%. In Tonnis 2/3 hips younger than 2 years, Severin grading was comparable following CR and OR, with 92% and 90% graded as Severin 1, respectively. The rate of significant ON was higher after CR in Tonnis 2/3 hips (12%) than after OR (0%). Overall, Tonnis 4 hips did badly: 94% failed CR and following OR, further surgery for redislocation/residual dysplasia was required in 21%.

CONCLUSIONS

CR can be successful in Tonnis 2/3 bilateral hips, with acceptable rates of secondary surgery, ON, and Severin grading, the latter equivalent to open reduction. Importantly, persisting with casting of a unilateral dislocation, to allow the contra-lateral hip to stabilize, does not have an adverse effect. CR is not advised in Tonnis 4 bilateral hips. Parents should be counseled that the outcome of surgery for bilateral hips is not as good as for unilateral DDH, particularly for Tonnis 4 hips which are more difficult to stabilize and more likely to require supplementary surgery even after open reduction.

LEVEL OF EVIDENCE

Level IV-Therapeutic Study.

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.

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.

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.

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.