Intraoperative 3D Fluoroscopy During Open Reduction for DDH: An Effective Alternative to Postoperative CT/MRI.

BACKGROUND: Computed tomography CT or magnetic resonance imaging (MRI) has been the most used imaging modality to assess hip reduction in developmental dysplasia of the hip (DDH) after open reduction (OR). In 2015, intraoperative 3D fluoroscopy (3D) was introduced at our center as an alternative to CT/MRI. 3D offers the advantage that if hip reduction is insufficient, it can be addressed at the time of surgery. The purpose of this study was to assess the efficacy of 3D in comparison to CT/MRI. METHODS: This was a single-centre, retrospective comparative study of two consecutive cohorts: those with OR and 3D between 2015 and 2017 and those with OR and CT/MRI between 2012 and 2014. Time to imaging, re-imaging, length of stay (LOS), re-operation, and redislocation or subluxation after cast removal were evaluated. RESULTS: Forty-two patients (46 hips) had 3D, and 30 patients (32 hips) had CT/MRI. Significant differences were found between groups in time to imaging, cast changes, and LOS. All 3D was intraoperative (46 hips), and only 69% (22 hips) of CT/MRI was on the day of surgery (P<0.01). In the 3D group, 1 hip (2%) had a cast change under the same anesthetic, and 4 hips (13%) from CT/MRI had cast changes in subsequent surgery (P=0.03). The mean LOS in days for 3D was 1.72 and 2.20 for CT/MRI (P=0.03). There were no statistically significant differences between groups in further imaging and subluxations or re-dislocations at cast removal. Two hips (4%) in the 3D group had MRI, but with no further intervention (P=0.51), and at cast removal, there were 3 subluxations in each group (P=0.69) and 1 redislocation in the 3D group (P=1.00). CONCLUSIONS: Intraoperative 3D improved time to imaging, allowed for cast changes at surgery and had a shorter LOS. Moreover, there were no significant differences found in adverse outcomes between those who underwent 3D versus CT/MRI. 3D should thus be considered an effective alternative to CT/MRI for assessing hip reduction during OR for DDH. LEVEL OF EVIDENCE: Diagnostic Study, level II.

A comprehensive nonoperative treatment protocol for developmental dysplasia of the hip in infants.

Aims: Brace treatment is the cornerstone of managing developmental dysplasia of the hip (DDH), yet there is a lack of evidence-based treatment protocols, which results in wide variations in practice. To resolve this, we have developed a comprehensive nonoperative treatment protocol conforming to published consensus principles, with well-defined a priori criteria for inclusion and successful treatment. Methods: This was a single-centre, prospective, longitudinal cohort study of a consecutive series of infants with ultrasound-confirmed DDH who underwent a comprehensive nonoperative brace management protocol in a unified multidisciplinary clinic between January 2012 and December 2016 with five-year follow-up radiographs. The radiological outcomes were acetabular index-lateral edge (AI-L), acetabular index-sourcil (AI-S), centre-edge angle (CEA), acetabular depth ratio (ADR), International Hip Dysplasia Institute (IHDI) grade, and evidence of avascular necrosis (AVN). At five years, each hip was classified as normal (< 1 SD), borderline dysplastic (1 to 2 SDs), or dysplastic (> 2 SDs) based on validated radiological norm-referenced values. Results: Of 993 infants assessed clinically and sonographically, 21% (212 infants, 354 abnormal hips) had DDH and were included. Of these, 95% (202 infants, 335 hips) successfully completed bracing, and 5% (ten infants, 19 hips) failed bracing due to irreducible hip(s). The success rate of bracing for unilateral dislocations was 88% (45/51 infants) and for bilateral dislocations 83% (20/24 infants). The femoral nerve palsy rate was 1% (2/212 infants). At five-year follow-up (mean 63 months (SD 5.9; 49 to 83)) the prevalence of residual dysplasia after successful brace treatment was 1.6% (5/312 hips). All hips were IHDI grade I and none had AVN. Four children (4/186; 2%) subsequently underwent surgery for residual dysplasia. Conclusion: Our comprehensive protocol for nonoperative treatment of infant DDH has shown high rates of success and extremely low rates of residual dysplasia at a mean age of five years.

Interobserver and Intraobserver Reliability in the Salter Classification of Avascular Necrosis of the Femoral Head in Developmental Dysplasia of the Hip.

BACKGROUND: Avascular necrosis (AVN) of the femoral head is a concerning complication that can result from treatments for developmental dysplasia of the hip (DDH). AVN can lead to degenerative osteoarthritis, persistent acetabular dysplasia, reduced function, and continuing hip pain. The incidence of AVN reported in the DDH literature is widely varied (0% to 73%). This variability may arise from lack of consensus on what constitutes true AVN in this patient population, and lack of clear criteria provided in studies reporting incidence rates. METHODS: A multicentre, prospective database of infants diagnosed with DDH between 2010 and 2014 from 0 to 18 months of age was analyzed for patients treated by closed reduction (CR). Twelve pediatric orthopaedic surgeons completed 2 rounds of AVN assessments. Deidentified anteroposterior radiographs at most recent follow-up were provided to surgeons along with patient age at radiographic assessment, length of follow-up, ands affected hip. Ten of 12 surgeons completed a third round of assessments where they were provided with 1 to 2 additional radiographs within the follow-up period. Radiographic criteria for total AVN described by Salter and colleagues were used. Surgeons rated the presence of AVN as "yes" or "no" and kappa values were calculated within and between rounds. RESULTS: A total of 69 hips in 60 patients were assessed for AVN a median of 22 months (range: 12 to 36) post-CR. Interobserver kappa values for rounds 1, 2, and 3 were 0.52 (range: 0.11 to 0.90), 0.61 (range: 0.21 to 0.90), and 0.53 (range: 0.10 to 0.79), respectively. Intraobserver agreement for AVN diagnosis was an average of 0.72 (range: 0.31 to 0.96). CONCLUSIONS: Despite using the most commonly referenced diagnostic criteria, radiographic diagnosis of AVN following CR in DDH patients demonstrated only moderate agreement across surgeons. The addition of sequential radiographs did not improve cross-observer reliability, and while substantial agreement was seen within observers, the range of intraobserver kappa values was large. LEVEL OF EVIDENCE: Level I-diagnostic study.

Predicting developmental dysplasia of the hip in at-risk newborns.

BACKGROUND: The development of developmental dysplasia of the hip can be attributed to several risk factors and often in combination with each other. When predicting the likelihood of developing this condition, clinicians tend to over and underestimate its likelihood of occurring. Therefore, the study aim is to determine among at-risk newborns how to best predict developmental dysplasia of the hip (DDH) within 8 weeks post-partum. METHODS: Prospective cohort study in secondary care. Patient population included newborns at-risk for DDH - we assessed 13,276 consecutive newborns for the presence of DDH risk factors. Only newborns with at least one of the predefined risk factors and those showing an abnormal examination of the hip were enrolled (n = 2191). For the development of a risk prediction model we considered 9 candidate predictors and other variables readily available at childbirth. The main outcome measure was ultrasonography at a median age of 8 weeks using consensus diagnostic criteria; outcome assessors were blinded. RESULTS: The risk model includes four predictors: female sex (OR = 5.6; 95% CI: 2.9-10.9; P <  0.001); first degree family history of DDH (OR = 4.5; 95% CI: 2.3-9.0; P <  0.001), birthweight > 4000 g (OR = 1.6; 95% CI: 0.6-4.2; P = 0.34), and abnormal examination of hip (OR = 58.8; 95% CI: 31.9, 108.5; P <  0.001). This model demonstrated excellent discrimination (C statistic = 0.9) and calibration of observed and predicted risk (P = 0.35). A model without the variable 'hip examination' demonstrated similar performance. CONCLUSION: The risk model quantifies absolute risk of DDH within 8 weeks postpartum in at-risk newborns. Based on clinical variables readily available at the point of childbirth, the model will enhance parental counselling and could serve as the basis for real time decisions prior to discharge from maternity wards.

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'.

Evaluation of Brace Treatment for Infant Hip Dislocation in a Prospective Cohort: Defining the Success Rate and Variables Associated with Failure.

BACKGROUND: The use of a brace has been shown to be an effective treatment for hip dislocation in infants; however, previous studies of such treatment have been single-center or retrospective. The purpose of the current study was to evaluate the success rate for brace use in the treatment of infant hip dislocation in an international, multicenter, prospective cohort, and to identify the variables associated with brace failure. METHODS: All dislocations were verified with use of ultrasound or radiography prior to the initiation of treatment, and patients were followed prospectively for a minimum of 18 months. Successful treatment was defined as the use of a brace that resulted in a clinically and radiographically reduced hip, without surgical intervention. The Mann-Whitney test, chi-square analysis, and Fisher exact test were used to identify risk factors for brace failure. A multivariate logistic regression model was used to determine the probability of brace failure according to the risk factors identified. RESULTS: Brace treatment was successful in 162 (79%) of the 204 dislocated hips in this series. Six variables were found to be significant risk factors for failure: developing femoral nerve palsy during brace treatment (p = 0.001), treatment with a static brace (p < 0.001), an initially irreducible hip (p < 0.001), treatment initiated after the age of 7 weeks (p = 0.005), a right hip dislocation (p = 0.006), and a Graf-IV hip (p = 0.02). Hips with no risk factors had a 3% probability of failure, whereas hips with 4 or 5 risk factors had a 100% probability of failure. CONCLUSIONS: These data provide valuable information for patient families and their providers regarding the important variables that influence successful brace treatment for dislocated hips in infants. LEVEL OF EVIDENCE: Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Education of parents in Pavlik harness application for developmental dysplasia of the hip using a validated simulated learning module.

BACKGROUND: The Pavlik harness is the most common initial treatment for developmental dysplasia of the hip worldwide. During treatment, parents are required to re-apply the harness at home. Teaching parents how to apply the harness is therefore paramount to success. While simulated learning for medical training is commonplace, it has not yet been trialed in teaching parents how to apply a Pavlik harness. METHODS: A group of parents underwent a simulated learning module for Pavlik harness application. Parents were evaluated pre- and post-exposure and at one month after testing. A validated objective structured assessment of technical skill (OSATS) and a global rating scale (GRS) specific to Pavlik harness application were used for evaluation. A control group of parents was also tested at both time points. A clinical expert group was used to determine competency. ANOVA and t tests were used to assess differences between groups and over time. RESULTS: Parent scores on the OSATS improved to the level of expert clinicians both immediately post-intervention and at retention testing. However, on the GRS, only half were considered competent due to their inability to achieve the required hip positions. The control group did not improve nor were they considered competent. CONCLUSIONS: The use of a simulated learning module improves both the confidence and skill level of parents in the application of the Pavlik harness. However, the challenges parents face in understanding the more detailed subtleties of medical care suggest that they still require an appropriate level of supervision by clinicians to ensure effective treatment.

Skill Acquisition and Retention Following Simulation-Based Training in Pavlik Harness Application.

BACKGROUND: Simulation-based learning is increasingly prevalent in many surgical training programs, as medical education moves toward competency-based curricula. In orthopaedic surgery, developmental dysplasia of the hip is a commonly treated condition, where the standard of care for patients less than six months of age is an orthotic device such as the Pavlik harness. However, despite widespread use of the Pavlik harness and the potential complications that may arise from inappropriate application, we know of no previously described formal training curriculum for Pavlik harness application. METHODS: We developed a video and model-based simulation learning module for Pavlik harness application. Two novice groups (residents and allied health professionals) were exposed to the module and, at pre-intervention, post-intervention, and retention testing, were evaluated on their ability to apply a Pavlik harness to the model. Evaluations were completed using a previously validated Objective Structured Assessment of Technical Skills (OSATS) and a global rating scale (GRS) specific to Pavlik harness application. A control group that did not undergo the module was also evaluated at two time points to determine if exposure to the Pavlik harness alone would affect skill acquisition. All groups were compared with a group of clinical experts, whose scores were used as a competency benchmark. Statistical analysis of skill acquisition and retention was conducted using t tests and analysis of variance (ANOVA). RESULTS: Exposure to the learning module improved resident and allied health professionals' competency in applying a Pavlik harness (p < 0.05) to the level of the expert clinicians, and this level of competency was retained one month after exposure to the module. Control subjects who were not exposed to the module did not improve, nor did they achieve competency. CONCLUSIONS: The simulation-based learning module was shown to be an effective tool for teaching the application of a Pavlik harness, and learners demonstrated retainable skills post-intervention. This learning module can form the cornerstone of formal teaching of Pavlik harness application for developmental dysplasia of the hip.

A Reliable and Valid Objective Structured Assessment of Technical Skill for the Application of a Pavlik Harness Based on International Expert Consensus.

BACKGROUND: The use of competency-based training is increasing in medical education as it offers individualized learning opportunities to master required skills. Inherent to this method of teaching is the need for standardized and objective assessments of skill mastery. In orthopaedic surgery, educational programs have focused on surgical skills with lesser emphasis on nonoperative techniques. Accordingly, formal evaluation tools specific to Pavlik Harness application do not exist, despite its widespread use and potential complications from inappropriate application. This study sought to develop a reliable and valid evaluation tool based on international expert consensus to standardize and evaluate Pavlik Harness application for developmental dysplasia of the hip. METHODS: Consensus was sought from 10 content experts using Delphi methodology. Resulting items formed the Objective Structured Assessment of Technical Skill (OSATS). Thirty-five participants were selected into 3 a priori groups (expert, intermediate and novice) based on Pavlik Harness experience. On 2 occasions, 3 content experts assessed randomized and deidentified videotapes of each participant applying a Pavlik Harness to an infant model using the OSATS and global rating scales (GRS). The reliability and validity of the OSATS was determined with intraclass (ICC) and Pearson correlations and analysis of variance (ANOVA). RESULTS: Consensus was obtained after 2 rounds of structured surveying and resulted in a 25-item OSATS. The reliability of the OSATS was excellent with an ICC of 0.96 for interrater and 0.98 for test-retest reliability. Construct validity was excellent with high correlations between OSATS and GRS (>0.90). In addition, the OSATS discriminated between expert, intermediate, and novice users. CONCLUSIONS: We have developed a competency-based evaluation tool for Pavlik Harness application based on consensus from international experts. The OSATS has been shown to be a reliable and valid method for assessing Pavlik Harness application that can discriminate between expert, intermediate, and novice users. LEVEL OF EVIDENCE: Level II.

How are dysplastic hips different? A three-dimensional CT study.

BACKGROUND: Surgical correction of acetabular dysplasia can postpone or prevent joint degeneration. The specific abnormalities that make up the dysplastic hip are controversial. QUESTIONS/PURPOSES: (1) What are the relative size, shape, and orientations of the typical nondysplastic hip? (2) How do these variables differ in the developmentally dysplastic hip? (3) Are there version differences between the acetabuli of dysplastic and nondysplastic hips? (4) Are there pairs of variables in which the change in one is always accompanied by a change in the other for both nondysplastic and dysplastic acetabuli? METHODS: Of 117 consecutive three-dimensional (3-D) CT scans performed for hip dysplasia between March 1988 and October 1995, 48 met criteria of developmentally dysplastic hips by plain radiography. These were retrospectively compared with 55 pelvic 3-D CT scans culled from 81 consecutive scans performed for reasons other than hip dysplasia (ie, hip pain, trauma, infection) that did not affect the hip or pelvic landmarks. The 3-D reconstructions were orientated anatomically for standardization of the measurements to be compared. Representative 3-D volumes of the acetabular space were constructed from which we could measure anatomic positions and dimensional information. One author performed all image orientation and measurements. RESULTS: Nondysplastic acetabuli are essentially hemispheric with height equal to width and twice the depth. The dysplastic acetabuli were elongated in females (52.4 ± 6.2 mm for dysplastic versus 46.5 ± 4.6 mm for nondysplastic (mean difference, 5.0; 95% confidence interval [CI], 1.9-8.0; p = 0.002) and shallower in both females (18.7 ± 4.9 mm for dysplastic versus 23.6 ± 4.0 mm for nondysplastic; mean difference, 6.5; 95% CI, 4.4-8.5; p < 0.0001) and males (21.1 ± 4.8 mm for dysplastic versus 25.0 ± 4.3 mm for nondysplastic, mean difference, 5.3; 95% CI, 2.6-8.1; p = 0.0002); width was similar to that of nondysplastic hips. Acetabular openings were slightly more vertical than nondysplastic hips in females (5°; 95% CI, 1.9-8.1; p = 0.002) but not in male subjects. The dysplastic acetabuli were smaller in volume (18% in females, p = 0.002, and 19% in males, p = 0.0012) and had less space occupied by the femoral head compared with nondysplastic hips (p < 0.0001 for females, p < 0.0001 for males). Dysplastic hip midacetabulum was 4° more anteverted in females (95% CI, 0.5-6.8; p = 0.022) but not for males (p = 0.538). The upper dysplastic acetabulum was more retroverted in females and males (10.2°; 95% CI, 5.5-15; p < 0.0001, and 7.0°; 95% CI, 0.6-13.4; p = 0.032, respectively). Acetabular volumes in nondysplastic and dysplastic hips were related to acetabular width but not to length. CONCLUSIONS: Developmentally dysplastic acetabuli are not deficient in merely a single dimension but are globally deficient. The subluxated femoral head lies in the elongated and retroverted superior acetabulum, which becomes progressively shallower as the acetabulum increases in length. Focally deficient anterior or posterior femoral head coverage is uncommon. Current procedures that redirect the acetabulum, no matter how technically successful, cannot fully compensate for the incongruence of a spherical femoral head within a shallow and elongated acetabulum unless corrected at an early age when acetabular remodeling is possible. Early detection and treatment of acetabular dysplasia should be emphasized. LEVEL OF EVIDENCE: Level III, prognostic study.

Management of hip instability in trisomy 21.

The unstable hip in Trisomy 21 presents with a spectrum of hip instability with different problems at different ages. What links this multiphase problem, in many patients, is the final common pathway of untreated instability, that of a stiff, dislocated, and often-painful hip, leading to significant functional disability. Historically, the results of treating hip instability in Trisomy 21 were variable with a notable frequency of poor results. With an improved understanding of the Trisomy 21 hip in terms of its pathoanatomy and a more contemporary surgical approach to hip reconstruction, much improved results can be expected and indeed have recently been shown. The mainstay of treatment for the habitual dislocation group presenting before 8 years of age is the femoral varus derotation osteotomy. The older group presenting with painful subluxation often show signs of secondary acetabular dysplasia and thus are best treated with redirectional acetabular osteotomy with or without the use of femoral varus derotation osteotomy. The presence of radiographic features of degenerative arthritis in the fixed dislocation group precludes the use of joint-preserving techniques for hip reconstruction, and these patients can achieve excellent results with total joint arthroplasty. The natural history, historical results, assessment, treatment, and management of complications of hip instability in Trisomy 21 are addressed in this paper.

Reliability of Bucholz and Ogden classification for osteonecrosis secondary to developmental dysplasia of the hip.

BACKGROUND: Osteonecrosis is perhaps the most important serious complication after treatment of developmental dysplasia of the hip (DDH). The classification by Bucholz and Ogden has been used most frequently for grading osteonecrosis in this context, but its reliability is not established and unreliability could affect the validity of studies reporting the outcome of treatment. QUESTIONS/PURPOSE: We established the interrater and intrarater reliabilities of this classification and analyzed the frequency and nature of disagreements. METHODS: Three pediatric hip surgeons, a musculoskeletal pediatric radiologist, and three orthopaedic trainees graded 39 radiographs (hips) according to the Bucholz and Ogden classification, blinded to any clinical data. Ratings were repeated after 2 weeks. Interrater reliability and intrarater reliability were determined using the simple kappa statistic. Grading was compared among raters, the nature and frequency of disagreements established, and subgroup analyses performed. RESULTS: Interrater reliability was 0.34 (95% CI = 0.28, 0.40) for all raters, and 0.31 (0.20 to 0.43) for the three surgeons. The best interrater reliability was observed between the radiologist and a surgeon with a kappa of 0.51 (0.30, 0.72). Intrarater reliability estimates ranged from 0.44 to 0.69. Raters disagreed regarding the grade of osteonecrosis in 26 of 39 hips (67%), with seven of 26 disagreements (27%) involving confusion between Grades I and II. CONCLUSIONS: The interrater reliability was lower than expected, considering the raters' experience. Distinguishing between Grades I and II was the most frequently observed problem. We believe that the low reliability was a result of an ambiguous classification scheme rather than the variability among the raters. Outcome studies of DDH based on this classification should be interpreted with caution. We recommend the development of a new classification with better prognostic ability. LEVEL OF EVIDENCE: Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Strategies to improve outcomes from operative childhood management of DDH.

The operative management of DDH is technically challenging. To achieve excellent results, surgeons need to select the most appropriate operative treatment, minimize the risk of complications, and be aggressive in the management of serious complications, such as redislocation and AVN, when they occur. We have described specific steps and strategies to assist in each of these key steps.

Standardized diagnostic criteria for developmental dysplasia of the hip in early infancy.

BACKGROUND: Clinicians use various criteria to diagnose developmental dysplasia of the hip (DDH) in early infancy, but the importance of these various criteria for a definite diagnosis is controversial. The lack of uniform, widely agreed-on diagnostic criteria for DDH in patients in this age group may result in a delay in diagnosis of some patients. QUESTIONS/PURPOSES: Our purpose was to establish a consensus among pediatric orthopaedic surgeons worldwide regarding the most relevant criteria for diagnosis of DDH in infants younger than 9 weeks. MATERIAL AND METHODS: We identified 212 potential criteria relevant for diagnosing DDH in infants by surveying 467 professionals. We used the Delphi technique to reach a consensus regarding the most important criteria. We then sent the survey to 261 orthopaedic surgeons from 34 countries. RESULTS: The response rate was 75%. Thirty-seven items were identified by surgeons as most relevant to diagnose DDH in patients in this age group. Of these, 10 of 37 (27%) related to patient characteristics and history, 13 of 37 (35%) to clinical examination, 11 of 37 (30%) to ultrasound, and three of 37 (8%) to radiography. A Cronbach alpha of 0.9 for both iterations suggested consensus among the panelists. CONCLUSION: We established a consensus regarding the most relevant criteria for the diagnosis of DDH in early infancy and established their relative importance on an international basis. The highest ranked clinical criteria included the Ortolani/Barlow test, asymmetry in abduction of 20° or greater, breech presentation, leg-length discrepancy, and first-degree relative treated for DDH. LEVEL OF EVIDENCE: Level IV, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Femoral varus derotation osteotomy for the treatment of habitual subluxation and dislocation of the pediatric hip in trisomy 21: a 10-year experience.

BACKGROUND: Habitual hip subluxation and dislocation are potentially disabling features of the trisomy 21 syndrome. We describe outcomes after a femoral varus derotation osteotomy to achieve and maintain hip stability and community ambulation. METHODS: All individuals with trisomy 21, who underwent hip surgery at our institution between 1998 and 2008, were searched using the hospital databases. The clinical notes and radiographs were reviewed from presentation to final follow-up. Nine children (16 hips) aged below 10 years, were identified. All had a femoral varus derotation osteotomy with a target femoral neck-shaft angle (NSA) of 105 degrees and external rotation of < 20 degrees of the distal fragment. All were performed by the senior author. RESULTS: Mean age at first known hip dislocation was 4.6 years (range, 4 to 5.2 y), mean age at surgery was 6.1 years (range, 5.2 to 7.0 y), and mean follow-up was 5.4 years (range, 3.8 to 7.1 y). Mean NSA fell postoperatively to 106.0 degrees (range, 103.1 to 110.2 degrees) from 166.7 degrees (range, 162.2 to 171.1 degrees). In 2 hips, intraoperative instability remained, requiring immediate periacetabular osteotomy and capsulorraphy.Postoperatively, all patients demonstrated an asymptomatic waddling gait, which persisted in 1 individual. Fourteen hips developed peritrochanteric varus deformities with a mean center of rotation and angulation of 21 degrees (range, 16 to 25 degrees). Two hips (12.5%) sustained implant-related fractures 4 and 8 years postoperatively. One hip (6.3%) developed arthritis and none had redislocated at latest follow-up. CONCLUSIONS: Sequelae from recurrent subluxation or dislocation of hips in trisomy 21 may require surgery to prevent eventual disability.We recommend a varus producing proximal femoral osteotomy correcting the NSA to approximately 105 degrees. This should be performed before the age of 7 years or a widened or V-shape teardrop develops. After 2 implant-related fractures, we recommend implant removal once the osteotomy has healed and the hip stabilized.In our experience, this approach is effective in maintaining hip stability. LEVEL OF EVIDENCE: A level 4 study, looking at a specific patient population undergoing a particular procedure.

The presence of an ossific nucleus does not protect against osteonecrosis after treatment of developmental dysplasia of the hip.

BACKGROUND: Osteonecrosis (ON) is a major complication after treatment of developmental dysplasia of the hip (DDH). Several studies have explored the absence of the femoral head ossific nucleus at the time of hip reduction as a risk factor for the development of ON, but findings have been inconsistent. QUESTIONS/PURPOSES: We therefore determined the incidence of ON in children who underwent reduction of a dislocated hip in the presence or absence of the ossific nucleus. PATIENTS AND METHODS: We retrospectively reviewed the radiographs of 105 hips in 89 patients treated for DDH at the age of 18 months or younger. Radiographs were graded for the presence of the ossific nucleus at the time of hip reduction and for the presence of ON, as graded by the Bucholz and Ogden classification, for patients at a mean age of 10 years. We used log-binomial regression to estimate if the presence of the ossific nucleus was associated with a lower incidence of ON. RESULTS: We identified ON in 37 of the 105 hips (35%). The incidence of ON at 10 years was 40% in the absence of the ossific nucleus and 32% in the presence of the ossific nucleus (adjusted relative risk, 0.86; 95% confidence interval, 0.36-1.81). When only radiographic changes of Grade II and greater were considered ON, the risk was still not increased (relative risk, 1.26; 95% confidence interval, 0.62-2.56). CONCLUSION: Patients with an ossific nucleus at the time of hip reduction showed a slight tendency toward better outcomes. The ossific nucleus did not protect for ON. LEVEL OF EVIDENCE: Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Functional outcomes in children with osteonecrosis secondary to treatment of developmental dysplasia of the hip.

BACKGROUND: Osteonecrosis of the femoral head is a major potential complication following the treatment of developmental dysplasia of the hip. It remains unclear if the radiographic changes associated with osteonecrosis are clinically relevant. METHODS: In the present cross-sectional study, we determined the relationship between morphological changes on radiographs (classified with use of the Bucholz-Ogden system) and health-related quality of life (assessed with the Health Utilities Index Mark 3 [HUI3]; maximum score, 1), physical function (assessed with the Activities Scale for Kids [ASK]; maximum score, 100), and hip function (assessed with the Children's Hospital Oakland Hip Evaluation Scale [CHOHES]; maximum score, 100). The study group included seventy-two children (mean age, 14 ± 2.5 years) with a diagnosis of osteonecrosis of the hip secondary to the treatment of developmental dysplasia of the hip. Patient assessments were standardized (intraclass correlation coefficient, ≥0.93). Radiographs were graded by three experts according to consensus. Analyses were adjusted for the number of previous surgical procedures on the hip and for the severity of residual hip dysplasia. RESULTS: The median ASK score was 97 (interquartile range, 93 to 100), the median CHOHES score was 86 (interquartile range, 77 to 96), and the median HUI3 score was 1 (interquartile range, 0.9 to 1). The ASK summary scores were nearly equal (median, >90) across all radiographic grades. Adjusted mean scores showed a downward shift with worse radiographic grades. The ASK scores (p = 0.004) and CHOHES scores (p = 0.006) differed across radiographic grades, with Bucholz-Ogden grade-I and II hips demonstrating significantly better scores than grade-III and IV hips. DISCUSSION: Osteonecrosis secondary to the treatment of developmental dysplasia of the hip is a relatively benign condition in children and teenagers. While it was associated with limited hip function, it was not associated with physical disability. However, we speculate that this function will decline with increasing age. With regard to clinical outcome, Bucholz-Ogden grade-I hips are similar to grade-II hips and grade-III hips are similar to grade-IV hips.