Agreement was reached that the optimum age for GSL surgery was 6 years to 10 years and should be avoided in children aged under 4 years. Physical examination measures with the child awake and under anaesthesia were important in decision making. Gait analysis was supported both for decision making and for assessing outcomes, in combination with patient reported outcomes (PROMS).
 
  The results from this study may encourage informed practice evaluation, reduce practice variability, improve clinical outcomes and point to questions for further research.
 
  V.
 V.
  Reimers migration percentage (MP) is the gold standard for measuring hip displacement in children with cerebral palsy (CP). Hip surveillance registries proposed using the top of the Gothic arch (GA) as a modification in patients with acetabular dysplasia because the classical method (CM) described by Reimers may underestimate hip migration. The aim of this study is to assess the inter- and intra-observer reliability of the modified method (MM) versus the CM and identify their effect on the MP.
 
  We performed a retrospective review of 50 children with CP, who had a hip radiograph at our institution between 1st April 2014 and 28th February 2018. All hip radiographs were carefully selected to show the presence of a GA. Four observers measured the MP using the CM and MM for each patient. Interclass coefficient was used to estimate inter- and intra-observer reliability.
 
  Inter-observer reliability was excellent for the CM with ICC 0.96 (95% CI 0.94 to 0.97) and good for the MM, ICC 0.78 (95% CI 0.51 to 0.89) p < 0.001. Intra-observer reliability was excellent for both methods raging from ICC 0.94 to 0.99 for the CM and ICC 0.89 to 0.95 for the MM. The mean MP was 19% for the CM and 28% for the MM (p < 0.001).
 
  The CM is more reliable than the MM to measure hip migration in children with CP. If the CM is used and acetabular dysplasia with a GA are present on the hip radiograph, then a 9% hip migration underestimation should be considered on decisions for both referral and surgical management.
 
  II.
 II.
  The study aimed to develop a scoring system based on clinical and radiological findings to predict the risk of a sequential slipped capital femoral epiphysis (SCFE).
 
  Paediatric patients with unilateral SCFE and at least two years of radiographic follow-up were screened for inclusion. Medical records were reviewed for multiple variables including age, gender, body mass index (BMI), stability of SCFE, and time to sequential presentation. Radiographic analysis included triradiate physeal status, Risser staging, superior epiphyseal extension ratio (EER), posterior epiphyseal angle (PEA), posterior sloping angle (PSA) and slip severity.
 
  In total, 163 patients (88 male, 54%, 75 female, 46%) met inclusion criteria. Of those, 65 (40%) with a mean age of 11.9 ± 1.3 years developed sequential SCFE at a mean of 9.8 ± 6.4 months after the initial slip. Eight independent variables were statistically different (p < 0.05) between unilateral and sequential groups. Following multivariate analysis, Risser stage and triradiate status were no longer significant and did not influence the strength of the final model (overall area under the curve (AUC) = 0.954) and were consequently excluded. We developed the PASS score using three radiographic parameters using chosen cut-off values that were close to their maximized value and weighted the point value assigned to each parameter based on the strength of predictor.
 
  A PASS score of three or higher predicts a high probability of sequential SCFE with 95% confidence and may warrant prophylactic screw fixation. PASS score calculation can be used to predict a sequential SCFE and provide an objective method to determine the utility prophylactic screw fixation.
 
  II.
 II.
  Double and triple femoral neck lengthening osteotomies have been described to correct coxa brevis deformity. Only small studies reported the results. Our aim was to provide an overview of the outcomes of double and triple femoral neck lengthening.
 
  After an extensive search of different online databases, we included studies reporting the results of double and triple femoral neck osteotomies.  https://www.selleckchem.com/products/PD-0332991.html  Clinical and radiological outcomes, and reported complications were extracted. The review process was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
 
  After evaluating 456 articles, we included 11 articles reporting 149 osteotomies in 143 patients (31% male, 64% female, 5% unspecified). Mean age of the patients was 20 years (range 7 years to 52 years). Indications were developmental hip dysplasia (51%), Perthes disease (27%), infection (6%), post-trauma (4%), congenital disorders (2%), slipped capital femoral epiphysis (1%), idiopathic (3%) and unknown (6%). The mean limb length discrepancy reduced by 12 mm (0 mm to 40 mm). In total, 65% of 101 positive Trendelenburg sign hips experienced improvement of abductor muscle strength. An 18% (9% to 36%) increase could be found in functional hip scores. Mean increase in articulo-trochanteric distance was 24 mm (10 mm to 34 mm). Five patients older than 30 years at the time of osteotomy and two younger patients with prior hip incongruency had disappointing results and required arthroplasty. In all, 12 complications occurred in 128 osteotomies, in which complications were reported.
 
  Double and triple femoral neck lengthening osteotomies in coxa brevis show good results with few complications in the literature, especially in young patients with non-arthritic hips.
 
  III.
 III.
  The objective of this study was to explore the predictors for failed reduction in children with developmental dysplasia of the hip (DDH) managed by arthrogram, closed reduction (CR) and spica cast immobilization.
 
  We retrospectively reviewed the clinical data of patients with DDH treated by CR and cast immobilization (2015-2020), including age, sex, affected side, presence/absence of an ossific nucleus, International Hip Dysplasia Institute classification, the delineation of labrum and acetabular surface on arthrogram, inverted labrum, acetabular index (AI), hip abduction angle and medial dye pool (MDP) distance. Predictors that potentially predicted failure of CR were evaluated by logistic regression analysis, simple t-test, Fisher's Exact Test and chi-square test.
 
  In total, 16 out of 187 hips failed to achieve initial CR (8.6%). Gender, age, preoperative AI and poor delineation of arthrogram were candidate predictors for failed CR in children aged six to 24 months with DDH; on the other hand, logistic regression analysis confirmed age and poor delineation of arthrogram significantly predicted failure of CR.