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.

Even Experts Can Be Fooled: Reliability of Clinical Examination for Diagnosing Hip Dislocations in Newborns.

BACKGROUND: The aim of this study was to assess the accuracy of clinical screening examination in newborns with dislocated hips compared with ultrasound scan (USS). METHODS: Newborns, up to 3 months of age, with confirmed hip dislocations on USS were prospectively enrolled in a multinational observational study. Data from 2010 to 2016 were reviewed to determine pretreatment clinical examination findings of the treating orthopaedic surgeon as well as baseline ultrasound indices of developmental dysplasia of the hip (DDH). All infants had been referred to specialist centres with expertise in DDH, due to abnormal birth examination or risk factor. RESULTS: The median age of the study population was 2.3 weeks and 84% of patients were female. Of the total 515 USS-confirmed dislocated hips included in the study, 71 (13.8%) were incorrectly felt to be reduced on clinical examination by the treating orthopaedist (P<0.001). Full hip abduction was documented in 106 hips. Of the hips correctly identified as dislocated, 322 hips were further analyzed based on clinical reducibility. Thirty-three of 322 (10.2%) were incorrectly thought to be reducible when in fact they were irreducible or vice versa. CONCLUSIONS: Expert examiners missed a significant number of frankly dislocated hips on clinical examination and their ability to classify hips based on clinical reducibility was only moderately accurate. This study provides evidence that, even in experienced hands, physical examination findings in DDH are often too subtle to elicit clinically in the first few months of life. This may explain the persistent and measurable rate of late presenting dislocations in countries with screening programmes reliant on clinical examination. LEVEL OF EVIDENCE: Level 1-testing of previously developed diagnostic criteria in series of consecutive patients (with universally applied reference "gold" standard).

Does Late Hip Dysplasia Occur After Normal Ultrasound Screening in Breech Babies?

BACKGROUND: Recent literature has raised concern regarding the occurrence of late dysplasia after normal screening in breech babies. One paper states a late dysplasia incidence of 29%. This finding is in contrast with other published work, which suggests breech presentation is predictive of spontaneous stabilization of the unstable neonatal hip. We decided to identify the rate of late dysplasia after normal screening in our patient cohort and also to investigate the use of a prophylactic abduction diaper. METHODS: During the study period of December 2012 to June 2014, breech babies referred to the screening program at our institution were identified. Ninety babies were prospectively enrolled into the study and randomized to either the observational arm or prophylactic treatment with the Healthy Hip Diaper (HALO, Minnetonka, MN). All babies had a normal initial clinical examination and ultrasound. Regular follow-up including clinical and ultrasound examination was undertaken culminating in pelvic x-rays performed at 13±1 months. A total of 63% of patients elected against their randomization to prophylactic treatment, 28% opted for prophylactic treatment against their randomization to observation only, meaning a total of 40% of babies proceeded against their initial randomization. In total, 75% of recruited babies completed follow-up. Dysplasia was defined as an acetabular index >2 SD from the mean sex, age, and side-specific values. RESULTS: The overall rate of radiographic dysplasia at 13 months was 7.4%. The rate was 5% in those using a Healthy Hip Diaper and 8.3% in those under observation only. This was not a statistically significant difference. Two patients required operative intervention, one requiring capsulorraphy with acetabuloplasty, the other requiring an arthrogram. Overall compliance with the abduction diaper was low. CONCLUSIONS: We conclude that late radiographic dysplasia does occur after normal clinical and ultrasound screening in breech babies, although not to the same extent as recently published data. We cannot recommend prophylactic abduction devices for breech babies who have a normal hip ultrasound at 6 weeks of age. Consideration must be given to further clinical and radiographic follow-up for hip dysplasia when the risk factor of breech presentation is present. LEVEL OF EVIDENCE: Level II-prospective comparative trial.

Management of Irreducible Hip Dislocations in Infants With Developmental Dysplasia of the Hip Diagnosed Below 6 Months of Age.

BACKGROUND: Infants with dislocated irreducible (D/I) hips can be substantially harder to treat than infants with dislocated but reducible hips. The purpose of this study was to compare treatment methods and outcomes for infants with D/I hips in order to optimize management of this difficult patient cohort. METHODS: A multicenter prospective hip dysplasia study database was analyzed from 2010 to 2016. Infants aged below 6 months with clinically and radiologically confirmed D/I hips were included in the study. Teratological hips (syndromic/neuromuscular) were excluded. RESULTS: In total, 59 hips in 52 patients were included. All hips were clinically Ortolani negative and radiologically dislocated but irreducible on presentation and had at least 20 months of follow-up. Mean age at diagnosis was 1.9 months (range, 0.1 to 5.9 mo). There were 33 left hips, 12 right hips, and 14 bilateral hips (7 patients). In total, 48 of 59 hips were treated in Pavlik harness. The remainder were treated by alternative braces or primary closed or open reductions. Pavlik treatment was successful in 27 of 48 hips. Pavlik treatment was abandoned in 21 D/I hips, 3 due to femoral nerve palsy and the remainder due to failure to achieve reduction. There was no statistical correlation between Pavlik success and age at diagnosis (P=0.22), patient sex (P=0.61), or bilateral compared with unilateral D/I hips (P=0.07). Left hips were more likely to be successfully reduced in Pavlik harness than right hips (P=0.01). Five complications occurred: 3 patients developed femoral nerve palsy in Pavlik harness, while 2 patients developed avascular necrosis, both after failed Pavlik treatment and subsequent surgery. CONCLUSIONS: Pavlik harness treatment has been demonstrated to be a safe and sensible first-line treatment for infants with D/I hips. Left hips were more likely to be successfully reduced in Pavlik harness than right hips, but age, sex, and bilaterality were not correlated. The outcomes demonstrated from this multicentre prospective database inform management of this complex patient cohort. LEVEL OF EVIDENCE: Level II-prognostic study: less-quality prospective 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.

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.

What Is the Impact of Center Variability in a Multicenter International Prospective Observational Study on Developmental Dysplasia of the Hip?

BACKGROUND: Little information exists concerning the variability of presentation and differences in treatment methods for developmental dysplasia of the hip (DDH) in children < 18 months. The inherent advantages of prospective multicenter studies are well documented, but data from different centers may differ in terms of important variables such as patient demographics, diagnoses, and treatment or management decisions. The purpose of this study was to determine whether there is a difference in baseline data among the nine centers in five countries affiliated with the International Hip Dysplasia Institute to establish the need to consider the center as a key variable in multicenter studies. QUESTIONS/PURPOSES: (1) How do patient demographics differ across participating centers at presentation? (2) How do patient diagnoses (severity and laterality) differ across centers? (3) How do initial treatment approaches differ across participating centers? METHODS: A multicenter prospective hip dysplasia study database was analyzed from 2010 to April 2015. Patients younger than 6 months of age at diagnosis were included if at least one hip was completely dislocated, whereas patients between 6 and 18 months of age at diagnosis were included with any form of DDH. Participating centers (academic, urban, tertiary care hospitals) span five countries across three continents. Baseline data (patient demographics, diagnosis, swaddling history, baseline International Hip Dysplasia Institute classification, and initial treatment) were compared among all nine centers. A total of 496 patients were enrolled with site enrolment ranging from 10 to 117. The proportion of eligible patients who were enrolled and followed at the nine participating centers was 98%. Patient enrollment rates were similar across all sites, and data collection/completeness for relevant variables at initial presentation was comparable. RESULTS: In total, 83% of all patients were female (410 of 496), and the median age at presentation was 2.2 months (range, 0-18 months). Breech presentation occurred more often in younger (< 6 months) than in older (6-18 months at diagnosis) patients (30% [96 of 318] versus 9% [15 of 161]; odds ratio [OR], 4.2; 95% confidence interval [CI], 2.3-7.5; p < 0.001). The Australia site was underrepresented in breech presentation in comparison to the other centers (8% [five of 66] versus 23% [111 of 479]; OR, 0.3, 95% CI, 0.1-0.7; p = 0.034). The largest diagnostic category was < 6 months, dislocated reducible (51% [253 of 496 patients]); however, the Australia and Boston sites had more irreducible dislocations compared with the other sites (ORs, 2.1 and 1.9; 95% CIs, 1.2-3.6 and 1.1-3.4; p = 0.02 and 0.015, respectively). Bilaterality was seen less often in older compared with younger patients (8% [seven of 93] versus 26% [85 of 328]; p < 0.001). The most common diagnostic group was Grade 3 (by International Hip Dysplasia Institute classification), which included 58% (51 of 88) of all classified dislocated hips. Splintage was the primary initial treatment of choice at 80% (395 of 496), but was far more likely in younger compared with older patients (94% [309 of 328] versus 18% [17 of 93]; p < 0.001). CONCLUSIONS: With the lack of strong prognostic indicators for DDH identified to date, the center is an important variable to include as a potential predictor of treatment success or failure.

Vitamin D Deficiency in Slipped Upper Femoral Epiphysis: Time to Physeal Fusion.

BACKGROUND: Slipped upper femoral epiphysis (SUFE) has an incidence of 1 to 7 per 100,000 adolescents in the United Kingdom and its link with obesity is well established. With an increasing number of pediatric orthopaedic patients presenting with vitamin D deficiency, the aim of our study was to establish the prevalence of vitamin D deficiency in SUFE patients presenting to an orthopaedic department in the United Kingdom and whether a low vitamin D level increases the time to proximal femoral physeal fusion after surgical fixation. METHODS: A total of 27 pediatric patients, with a female to male ratio of 17:10 and a mean age of 11.5 years (SD=1.99), range 8 to 16 years, presented with a SUFE and their vitamin D level was assessed during the study period, June 2007 to July 2012 (inclusive). The majority of these patients (85.2%) were assessed as vitamin D deficient, with a serum 25-(OH)D<52 nmol/L. The time taken for >50% physeal fusion on anteroposterior radiography after surgical fixation reported in the literature is 9.6 months, with no reported vitamin D deficiency or insufficiency. RESULTS: In our study, the median time to physeal fusion in the vitamin D-deficient and vitamin D-insufficient patients was 25 months (interquartile range, 17 to 43 mo; mean of 29 mo, SD=16.8). A negative correlation was also observed between vitamin D level and the time taken for physeal fusion after surgical fixation. CONCLUSIONS: We conclude that a high prevalence of vitamin D deficiency has been observed in our SUFE patients. Comparing the time taken for physeal closure of 9.6 months in the literature with vitamin D-deficient patients, this is prolonged. Indeed, a negative correlation has been shown between vitamin D level and time to physeal fusion. This study highlights the need for regular vitamin D status assessment in SUFE patients to allow early implementation of treatment with vitamin D supplementation. The impact of vitamin D screening and supplementation on SUFE outcomes should be investigated further.

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.

Shelf acetabuloplasty for containment in the early stages of Legg-Calve-Perthes disease.

BACKGROUND: To evaluate the effectiveness of shelf acetabuloplasty in the containment of extruded hips without hinge abduction in early stages of Legg-Calve-Perthes disease, we present a retrospective series of 44 patients (45 hips) treated between August 1999 and February 2010, which included 34 boys and 10 girls with a mean age at diagnosis of 7.4 years (range, 3.9 to 15.3). METHODS: All patients presented with sclerosis or early fragmentation stages. The average time from diagnosis to surgery was 2.1 months (range, 0 to 8.2) and the mean time to heal was 40.4 months (range, 20 to 82.2). The Reimer migration and the deformity indices were measured on initial, preoperative, postoperative, and healed x-rays. The average deformity index at 3 of those 4 timepoints was significantly related to their final Stulberg classification. CE angles increased and Sharp angles decreased significantly as a result of treatment. RESULTS: At the healed stage and consistent with other published series, 84.4% of patients were Stulberg III or less, denying any pain, and with full range of movement, whereas 15.6% were classified as Stulberg IV. CONCLUSIONS: We defend that shelf acetabuloplasty should be performed early in the disease and, uniquely, we propose that the indication for treatment should be guided by the deformity and the Reimer migration indices. LEVEL OF EVIDENCE: IV.

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.

Reliability of a New Radiographic Classification for Developmental Dysplasia of the Hip.

BACKGROUND: Existing radiographic classification schemes (eg, Tönnis criteria) for DDH quantify the severity of disease based on the position of the ossific nucleus relative to Hilgenreiner's and Perkin's lines. By definition, this method requires the presence of an ossification centre, which can be delayed in appearance and eccentric in location within the femoral head. A new radiographic classification system has been developed by the International Hip Dysplasia Institute (IHDI), which uses the mid-point of the proximal femoral metaphysis as a reference landmark, and can therefore be applied to children of all ages. The purpose of this study was to compare the reliability of this new method with that of Tönnis, as the first step in establishing its validity and clinical utility. METHODS: Twenty standardized anteroposterior pelvic radiographs of children with untreated DDH were selected purposefully to capture the spectrum of age (range, 3 to 32 mo) at presentation and disease severity. Each of the hips was classified separately by the IHDI and Tönnis methods by 6 experienced pediatric orthopaedists from the United States, Canada, Mexico, United Kingdom, and by 2 orthopaedic senior residents. The inter-rater reliability was tested using the Intra Class Correlation coefficient (ICC) to measure concordance between raters. RESULTS: All 40 hips were classifiable by the IHDI method by all raters. Ten of the 40 hips could not be classified by the Tönnis method because of the absence of the ossific nucleus on one or both sides. The ICC (95% confidence interval) for the IHDI method for all raters was 0.90 (0.83-0.95) and 0.95 (0.91-0.98) for the right and left hips, respectively. The corresponding ICCs for the Tönnis method were 0.63 (0.46-0.80) and 0.60 (0.43-0.78), respectively. There was no significant difference between the ICCs of the 6 experts and 2 trainees. CONCLUSIONS: The IHDI method of classification has excellent inter-rater reliability, both among experts and novices, and is more widely applicable than the Tönnis method as it can be applied even when the ossification centre is absent. LEVEL OF EVIDENCE: Level II (diagnostic).

Developmental dysplasia of the hip: diagnosis and management to 18 months.

Developmental dysplasia of the hip represents a spectrum of disease ranging from transient neonatal instability to established dislocation. It is accepted that female sex, breech presentation, and family history are risk factors for the disease. Early diagnosis by clinical examination or ultrasound imaging is emphasized, with splint treatment ideally commencing by 6 weeks of age. Treatment using the Pavlik harness is successful in up to 90% of patients. Ultrasound imaging is the gold standard for monitoring a patient during harness wear. Failed splintage or late presentation usually necessitates surgical intervention depending on the patient's age and the severity of the hip dysplasia and displacement.

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.

An Explorative Study into the Aetiology of Developmental Dysplasia of the Hip Using Targeted Urine Metabolomics.

Developmental dysplasia of the hip (DDH) is the most prevalent congenital musculoskeletal disorder, yet its cause remains unknown. Adequate nutrient provision and coordinated electron exchange (redox) processes are critical for foetal growth and tissue development. This novel study sought to explore specific biochemical pathways in skeletal development for potential involvement in the aetiology of DDH. Spot urine samples were collected from infants, aged 13-61 days, with and without DDH. Ion chromatography-mass spectrometry was used to quantify thiosulphate, sulphate, nitrate, and phosphate, whilst nitrite was quantified using high-performance liquid chromato-graphy. Thiobarbituric acid reactive substances (TBARS) were measured as markers of lipid peroxidation. Creatinine and osmolality were determined by a 96-well plate assay and micro-osmometer to potentially normalise values for renal function, lean body mass, and hydration status. Urine samples were analysed from 99 babies: 30 with DDH and 69 age-matched non-DDH controls. Thiosulphate, TBARS, and creatinine concentrations differed between the DDH group and the controls (p = 0.025, 0.015, and 0.004 respectively). Urine osmolality was significantly lower in DDH compared to the controls (p = 0.036), indicative of the production of a more diluted urine in DDH infants. Following adjustment for osmolality, significant differences became apparent in urinary sulphate levels in DDH (p = 0.035) whereas all other parameters were similar between the groups. This is the first study to assess the potential role of these inorganic anions in DDH. The higher levels of sulphate found in infants with DDH suggests either enhanced intake from milk, increased endogenous formation, or impaired renal reabsorption. This investigation demonstrates the power of urine metabolomics and highlights the importance of normalisation for hydration status to disentangle developmental disorders. Our results strongly suggest that DDH is a systemic disease associated with altered uptake, formation, or handling of sulphate. There is potential for new opportunities in the prevention or treatment of DDH via nutritional intervention.

Vitamin D deficiency: a paediatric orthopaedic perspective.

PURPOSE OF REVIEW: At the turn of the last century, rickets (vitamin D deficiency) was one of the most common musculoskeletal diseases of the paediatric population presenting to physicians. Today, the most common referral pathway for these patients ends in a paediatric orthopaedic outpatient clinic. Vitamin D deficiency is a clinical entity that can affect all children and should be looked for in all children with musculoskeletal symptoms. RECENT FINDINGS: The child at risk of rickets is now white, breastfed, protected from the sun and obese. Vitamin D deficiency can present as atypical muscular pain, pathological fractures or slipped upper femoral epiphysis. Obesity is linked with lower vitamin D levels; however, in the paediatric population, this does not necessarily equal clinical disorder. Vitamin D supplements can be used to reduce the risk of pathological fractures in the cerebral palsy child. It should also form part of the differential diagnosis in the work-up of nonaccidental injuries. Children with a low vitamin D present with a higher incidence of fractures from normal activities. Vitamin D levels need to be assessed before any form of orthopaedic surgery, as it can affect growth, both in the diaphysis of the bone and in the growth plate. SUMMARY: Vitamin D levels are a key element in the successful practice of paediatric orthopaedics. It is not just the possible cause of disorder presenting to the clinician but also extremely important in ensuring the successful postoperative recovery of the patient.

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.

Bilateral acromial fractures in a neonate with epileptic encephalopathy.

We present a case of a newborn male with seizures who on subsequent radiographs was shown to have bilateral acromial fractures. These are uncommon fractures and are described in association with nonaccidental injury (NAI). However, in this case NAI was thought unlikely due to continuous hospitalisation of the boy. The possible aetiologies are discussed.

Sugioka transtrochanteric valgus osteotomy for hinge abduction in children.

UNLABELLED: We report our experience of Sugioka transtrochanteric valgus osteotomy (TVO) for hinge abduction in children. The advantages are early union with simple fixation and preservation of proximal femoral geometry. Lateral displacement of the greater trochanter improves abductor limp. A total of 24 patients of mean age 10.2 years underwent TVO. The neck shaft angle increased by mean 11.75 degrees. Migration index increased by mean 3.88%. Average limb length discrepancy at final follow-up was 10.8 mm. The mean modified Iowa hip score was 75.1. Our results indicate that Sugioka TVO is a successful procedure for hinge abduction of the hip. LEVEL OF EVIDENCE: Level IV (case series).

Epidemiology of vitamin D deficiency in children presenting to a pediatric orthopaedic service in the UK.

BACKGROUND: Vitamin D deficiency may increase predisposition to a number of pediatric orthopaedic conditions and the prevalence of vitamin D deficiency is increasing in children in developed countries. The aim of this study was to determine the epidemiology of vitamin D deficiency and insufficiency in children presenting to a regional pediatric orthopaedic service. We also examined the relationships between vitamin D status, social deprivation, and ethnicity. METHODS: Individuals of age 18 years and younger presenting to the regional pediatric orthopaedic service at Southampton, UK from 2008 to 2010 were investigated. Deprivation index scores were calculated from indices of deprivation. RESULTS: A total of 187 children (97 male, 90 female, mean age 7.1 y) underwent serum 25-hydroxyvitamin D level measurement. Of them 82% were white British and 11% were of Asian ethnicity. The calculation of the total depravation index for the whole cohort showed 34 patients (18%) were in quartile 1 (most deprived), 54 (29%) in quartile 2, 49 (26%) in quartile 3, and 50 (27%) in quartile 4 (least deprived). Sixty patients (32%) had vitamin D insufficiency with 25-(OH) levels <50 nmol/L and 15 patients (8%) had vitamin D deficiency. No relationship was identified between vitamin D level and social deprivation score. CONCLUSIONS: There is a need for awareness of the prevalence of vitamin D deficiency in the pediatric orthopaedic population presenting with bone pain and lower limb deformity before commencing "observation or orthopaedic surgical treatment." LEVEL OF EVIDENCE: 3.