Controversy remains whether the contralateral hip should be fixed in patients presenting with unilateral slipped capital femoral epiphysis (SCFE). This retrospective study compares the outcomes and cost of those patients who had prophylactic fixation with those who did not. Between January 2000 and December 2010 a total of 50 patients underwent unilateral fixation and 36 had prophylactic fixation of the contralateral hip. There were 54 males and 32 females with a mean age of 12.3 years (9 to 16). The rate of a subsequent slip without prophylactic fixation was 46%. The risk of complications was greater, the generic health measures (Short Form-12 physical (p < 0.001) and mental (p = 0.004) summary scores) were worse. Radiographic cam lesions in patients presenting with unilateral SCFE were only seen in patients who did not have prophylactic fixation. Furthermore, prophylactic fixation of the contralateral hip was found to be a cost-effective procedure, with a cost per quality adjusted life year gained of £1431 at the time of last follow-up. . Prophylactic fixation of the contralateral hip is a cost-effective operation that limits the morbidity from the complications of a further slip, and the diminished functional outcome associated with unilateral fixation. . Cite this article: Bone Joint J 2015;97-B:1428–34

Aims. Early detection of developmental dysplasia of the hip (DDH) is associated with improved outcomes of conservative treatment. Therefore, we aimed to evaluate a novel screening programme that included both the primary risk factors of breech presentation and family history, and the secondary risk factors of oligohydramnios and foot deformities. Methods. A five-year prospective registry study investigating every live birth in the study’s catchment area (n = 27,731), all of whom underwent screening for risk factors and examination at the newborn and six- to eight-week neonatal examination and review. DDH was diagnosed using ultrasonography and the Graf classification system, defined as grade IIb or above or rapidly regressing IIa disease (≥4. o. at four weeks follow-up). Multivariate odds ratios were calculated to establish significant association, and risk differences were calculated to provide quantifiable risk increase with DDH, positive predictive value was used as a measure of predictive efficacy. The cost-effectiveness of using these risk factors to predict DDH was evaluated using NHS tariffs (January 2021). Results. The prevalence of DDH that required treatment within our population was 5/1,000 live births. The rate of missed presentation of DDH was 0.43/1000 live births. Breech position, family history, oligohydramnios, and foot deformities demonstrated significant association with DDH (p < 0.0001). The presence of breech presentation increased the risk of DDH by 1.69% (95% confidence interval (CI) 0.93% to 2.45%), family history by 3.57% (95% CI 2.06% to 5.09%), foot deformities by 8.95% (95% CI 4.81% to 13.1%), and oligohydramnios nby 11.6% (95 % CI 3.0% to 19.0%). Primary risk factors family history and breech presentation demonstrated an estimated cost-per-case detection of £6,276 and £11,409, respectively. Oligohydramnios and foot deformities demonstrated a cost-per-case detected less than the cost of primary risk factors of £2,260 and £2,670, respectively. Conclusion. The inclusion of secondary risk factors within a national screening programme was clinically successful as they were more cost and resource-efficient predictors of DDH than primary risk factors, suggesting they should be considered in the national guidance. Cite this article: Bone Jt Open 2023;4(4):234–240

Aims. To investigate the risk factors for unsuccessful radial head reduction (RHR) in children with chronic Monteggia fractures (CMFs) treated surgically. Methods. A total of 209 children (mean age 6.84 years (SD 2.87)), who underwent surgical treatment for CMFs between March 2015 and March 2023 at six institutions, were retrospectively reviewed. Assessed risk factors included age, sex, laterality, dislocation direction and distance, preoperative proximal radial metaphysis width, time from injury to surgery, reduction method, annular ligament reconstruction, radiocapitellar joint fixation, ulnar osteotomy, site of ulnar osteotomy, preoperative and postoperative ulnar angulation, ulnar fixation method, progressive ulnar distraction, and postoperative cast immobilization. Independent-samples t-test, chi-squared test, and logistic regression analysis were used to identify the risk factors associated with unsuccessful RHR. Results. Redislocation occurred during surgery in 48 patients (23%), and during follow-up in 44 (21.1%). The mean follow-up of patients with successful RHR was 13.25 months (6 to 78). According to the univariable analysis, time from injury to surgery (p = 0.002) and preoperative dislocation distance (p = 0.042) were identified as potential risk factors for unsuccessful RHR. However, only time from injury to surgery (p = 0.007) was confirmed as a risk factor by logistic regression analysis. Receiver operating characteristic curve analysis and chi-squared test confirmed that a time from injury to surgery greater than 1.75 months increased the rate of unsuccessful RHR above the cutoff (p = 0.002). Conclusion. Time from injury to surgery is the primary independent risk factor for unsuccessful RHR in surgically treated children with CMFs, particularly in those with a time from injury to surgery of more than 1.75 months. No other factors were found to influence the incidence of unsuccessful RHR. Surgical reduction of paediatric CMFs should be performed within the first two months of injury whenever possible. Cite this article: Bone Jt Open 2024;5(7):581–591

Aims. We aimed to assess the cumulative risk of total hip arthroplasty (THA) from in situ fixation for slipped capital femoral epiphysis (SCFE) after a follow-up of almost 50 years. Methods. In this study, 138 patients with 172 affected hips treated with in situ fixation were evaluated retrospectively. A total of 97 patients (70%) were male and the mean age was 13.6 years (SD 2.1); 35 patients (25%) had a bilateral disease. The median follow-up time was 49 years (interquartile range 43 to 55). Basic demographic, stability, and surgical details were obtained from patient records. Preoperative radiographs (slip angle; SA) were measured, and data on THA was gathered from the Finnish National Arthroplasty Register. Results. The preoperative SA was a mean of 39° (SD 19°). At follow-up, 56 of the patients had undergone THA for a hip previously fixed in situ for SCFE (41%) and 64 of all affected hips had been replaced (37%). Kaplan-Meier analysis gave a median prosthesis-free postoperative survival of 55 years (95% confidence interval (CI) 45 to 64) for the affected hips. In a multivariate analysis, female patients had a two-fold risk for THA (hazard ratio (HR) 2.42 (95% CI 1.16 to 5.07)) and a greater preoperative SA increased the risk of THA (HR 1.03 for every increment of 1° (95% CI 1.01 to 1.05)), while patient age at surgery, slip laterality, stability of slip, or diagnostic delay did not have a statistically significant effect on the risk of THA. Conclusion. SCFE treated primarily with in situ fixation may lead to THA in more than 40% of affected hips at a near 50-year follow-up. This risk is approximately 15-times the reported lifetime risk in the Finnish general population. Female sex and increasing preoperative SA significantly predicted higher risk of THA. Cite this article: Bone Joint J 2023;105-B(12):1321–1326

Aims. The aim of this study was to clarify the factors that predict the development of avascular necrosis (AVN) of the femoral head in children with a fracture of the femoral neck. Patients and Methods. We retrospectively reviewed 239 children with a mean age of 10.0 years (. sd. 3.9) who underwent surgical treatment for a femoral neck fracture. Risk factors were recorded, including age, sex, laterality, mechanism of injury, initial displacement, the type of fracture, the time to reduction, and the method and quality of reduction. AVN of the femoral head was assessed on radiographs. Logistic regression analysis was used to evaluate the independent risk factors for AVN. Chi-squared tests and Student’s t-tests were used for subgroup analyses to determine the risk factors for AVN. Results. We found that age (p = 0.006) and initial displacement (p = 0.001) were significant independent risk factors. Receiver operating characteristic (ROC) curve analysis indicated that 12 years of age was the cut-off for increasing the rate of AVN. Severe initial displacement (p = 0.021) and poor quality of reduction (p = 0.022) significantly increased the rate of AVN in patients aged 12 years or greater, while in those aged less than 12 years, the rate of AVN significantly increased only with initial displacement (p = 0.048). A poor reduction significantly increased the rate of AVN in patients treated by closed reduction (p = 0.026); screw and plate fixation was preferable to cannulated screw or Kirschner wire (K-wire) fixation for decreasing the rate of AVN in patients treated by open reduction (p = 0.034). Conclusion. The rate of AVN increases with age, especially in patients aged 12 years or greater, and with the severity of displacement. In patients treated by closed reduction, anatomical reduction helps to decrease the rate of AVN, while in those treated by open reduction, screw and plate fixation was preferable to fixation using cannulated screws or K-wires. Cite this article: Bone Joint J 2019;101-B:1160–1167

Purpose. This 20-year prospective longitudinal observational study aims to determine the incidence of pathological developmental dysplasia of the hip (DDH) in children referred with clicky hips and define the risk posed to inform neonatal hip screening programmes including the role of ultrasound. Method. 355 children from 1997 to 2016 were referred with clicky hips to our “one stop” paediatric hip clinic under the local neonatal hip screening programme. Hips were assessed clinically for instability and by ultrasound using a simplified Graf classification. Dislocated or dislocatable hips were classed as Graf type IV. Results. The mean age at presentation was 13.9 (1–56) weeks. 343 out of 355 (96.6%) were Graf type I which required no treatment. 9 (2.5%) were Graf type II but all converted to Graf type I on follow up scans. 2 (0.6%) had Graf type III dysplasia and 1 (0.3%) had irreducible dislocation but all three were associated with limited hip abduction or other hip pathology. Referrals increased from 12.9 to 22.6 per year (p=0.002) from first decade of the study to the second, driven by rising primary care referrals (5.5 vs. 16.5 per year p=0.00002). Conclusion. The study provided robust evidence that overwhelming majority of clicky hips required no treatment other than reassurance to parents. Clicky hips with normal hip examination should be considered a variant of normal childhood and not a risk factor for DDH. However clicky hips with limited hip abduction may represent a separate clinical entity at risk of hip pathology and therefore warrant further investigations

A 15 year prospective, observational cohort study was undertaken to assess selective screening of DDH in males and females referred with risk factors only. Individuals born breech or with evidence of a strong family history for DDH were the ‘risk factors’ studied. All were clinically examined and sonographically screened by one Consultant Paediatric Orthopaedic surgeon. Irreducible hip dislocation rate was the primary outcome measure. From a cohort of 64670 live births, 2,984 neonates/infants, 46.1 per 1000 live births [95% CI 44.6 to 47.8 per 1000 live births] were referred and sonographically screened with ‘pure’ risk factors of breech presentation and/or family history, with clinical stability. 1360 were male, of which 4 were identified as having ‘pathological’ DDH; an incidence of 1 in 333 of those males referred [95 CI 0.001, 0.008]. 1624 were female, of which 45 were identified as having ‘pathological’ DDH; an incidence of 1 in 36 of those females referred [95% CI 0.021, 0.037]. There was a significant difference in the number of female individuals sonographically diagnosed as having ‘pathological’ DDH compared to males (p<0.001). Four individuals were diagnosed with irreducible hip dislocation, 0.06 per 1000 live births [95% CI 0.24, 0.159 per 1000 live births]. All were in females. Additionally, there were 2 female individuals; both with family history of DDH (1. st. cousin splinted and sister splinted, respectively) as a risk factor, referred late. Our study suggests that there is a significant difference between the incidence of female and male individuals diagnosed with ‘pathological’ DDH, in those referred purely with risk factors (breech and family history). These findings question the current screening policy for ultrasound examination of males with risk factors in the absence of clinical instability, and may influence future DDH screening programme policy. Level of evidence: II

The aim of this prospective study was to investigate prematurity as a risk factor for developmental dysplasia of the hip (DDH). The hips of 221 infants (88 female, 133 male, mean age 31.11 weeks; standard deviation (. sd. ) 2.51) who were born in the 34th week of gestation or earlier, and those of 246 infants (118 female, 128 male, mean age 40.22 weeks; . sd. 0.36) who were born in the 40th week of gestation, none of whom had risk factors for DDH, were compared using physical examination and ultrasound according to the technique of Graf, within one week, after the correction of gestational age to the 40th week after birth or one week since birth, respectively. Both hips of all infants were included in the study. Ortolani’s and Barlow’s tests and restricted abduction were accepted as positive findings on examination. There was a statistically significant difference between pre- and full-term infants, according to the incidence of mature and immature hips (p < 0.001). The difference in the proportion of infants with an α angle < 60° between the two groups was statistically significant (p < 0.001). The incidence of pathological dysplasia (α angle < 50 º) was not significantly different in the two groups (p = 1.000). The Barlow sign was present in two (0.5%) pre-term infants and in 14 (2.8%) full-term infants. . These results suggests that prematurity is not a predisposing factor for DDH. Cite this article: Bone Joint J 2015; 97-B:716–20

Aim. Although non-union is a devastating and costly consequence of trauma for the child, family and society it is felt to be a rare complication in children. Currently there is no data available in the literature regarding its incidence either per fracture or per head of population. Should we be taking paediatric fracture non-union more seriously regarding research, resource allocation and informed consent? Our aim was to determine the incidence of non-union per child and per fracture. Method. In Scotland Information Services Division (NHS Scotland) records every inpatient admission by ICD-10 diagnosis. As almost all fracture non-unions require intervention ISD provides accurate non-union figures by site and age. However, many fractures are treated as outpatients. Using local data of overall fracture numbers we were able to calculate a ratio of inpatient to total fracture numbers and apply this nationally. Results. Over a 5-year period there were 180 cases of non-union between the ages of 0–14 years, (4.21/100,000pa) and an incidence of 15,335 fractures/100,000pa giving an overall risk of 0.24% non-union per fracture. The risk of non-union per fracture did not change throughout childhood but notably increased in the late teenage years (15–19yrs). Both the incidence of fractures and non-union were far greater in boys, however incidence of non-union per fracture was similar in both sexes in childhood. Non-union per fracture was twice as frequent in the lower than upper limb, this trend reversed in the 15–19 year age group. Conclusion. The annual incidence of fractures in children is 15.3%, more frequent in the upper than lower limb; increasing with age, particularly in boys. The risk of non-union is around 1/400 per upper limb and 1/250 per lower limb fracture in childhood. Fracture non-union is rare in the paediatric population but even so 4.2 cases would be expected per 100,000 population or 240 cases per 100,000 fractures

Forearm fractures in children have a tendency to displace in a cast leading to malunion with reduced functional and cosmetic results. In order to identify risk factors for displacement, a total of 247 conservatively treated fractures of the forearm in 246 children with a mean age of 7.3 years (. sd. 3.2; 0.9 to 14.9) were included in a prospective multicentre study. Multivariate logistic regression analyses were performed to assess risk factors for displacement of reduced or non-reduced fractures in the cast. Displacement occurred in 73 patients (29.6%), of which 65 (89.0%) were in above-elbow casts. The mean time between the injury and displacement was 22.7 days (0 to 59). The independent factors found to significantly increase the risk of displacement were a fracture of the non-dominant arm (p = 0.024), a complete fracture (p = 0.040), a fracture with translation of the ulna on lateral radiographs (p = 0.014) and shortening of the fracture (p = 0.019). Fractures of both forearm bones in children have a strong tendency to displace even in an above-elbow cast. Severe fractures of the non-dominant arm are at highest risk for displacement. Radiographs at set times during treatment might identify early displacement, which should be treated before malunion occurs, especially in older children with less potential for remodelling. Cite this article: Bone Joint J 2013;95-B:689–93

Introduction:. Risk factors for developmental dysplasia of the hip (DDH) in early infancy have never been validated from basic principles; their relevance remains controversial. Purpose:. To determine risk factors for DDH using newly developed diagnostic criteria based on international consensus. Methods:. In this population-based cohort study, 9904 babies born at a secondary care unit (2010–2012) received a standardised examination (usually within 24 hours postpartum) in which we prospectively ascertained the presence of the common risk factors for DDH (breech, family history, etc). Infants exhibiting ≥1 factor were eligible and underwent ultrasound testing within 8 weeks. Alpha angles were measured by surgeon/radiologist in consensus and blinded to risk factors and age. Using multivariable methods we evaluated the association of the risk factors and ultrasonographic DDH using criteria based on international consensus. Results:. 1766 (18%) newborns exhibited ≥1 risk factor for DDH. Of these 1489 (84%) infants participated. To date, 1296 (87%) completed the ultrasound at a mean age of 8±3 weeks. Of the 1296, 55 (4%) patients exhibited alpha <55° and 43 (3%) exhibited alpha <50°. Of all risk factors, only female gender was associated with an alpha <55° (RR=2; 95% CI=1.1, 3.5; p=.01). In contrast, abnormal clinical examination findings of the hip were strongly associated with DDH (p<.0001). Conclusion:. In a prospective study using robust case definitions, commonly known risk factors were not clinically important markers of DDH when DDH was defined by consensus criteria. Given the generally poor and conflicting evidence on risk factors for DDH, our preliminary results suggest a new approach is needed in the risk prediction of DDH. Level of evidence: I

The purpose of the study was to identify risk factors that are associated with re-displacement of the hip after surgical reconstruction in cerebral palsy. Retrospective review of children with cerebral palsy who had hip reconstruction with proximal femoral varus derotation osteotomy (VDRO) and Dega-type pelvic osteotomy, between 2005–2012, at a UK and European institution, was performed. Patient demographics, GMFCS, clinical and radiological outcome were assessed as well as the presence of pelvic obliquity and significant scoliosis (Cobb angle > 10 degrees). Redisplacement was defined as Reimer's Migration Index (MI) >30% at final follow-up. Logistic regression analysis was used to assess which factors were predictive of redisplacement and adjusted for clustered variables (α = 0.05). Eighty hips were identified in 61 patients. The mean age at surgery was 8.8 years (± 3.3). Mean MI pre-op was 68% (± 23%) and post-op was 8% (± 12%). At a mean follow-up, of 3.2 years (± 2.0), 23 hips had a MI >30%. Of these; five were symptomatic, and one had required a salvage procedure. Metalwork removal was undertaken in 14 hips. Logistic regression demonstrated that the pre-operative MI and the percentage of acute correction were significant predictors of re-displacement. If the pre-operative MI was greater than 65 percent, the odds ratio (OR) for redisplacement was 5.99 (p = 0.04). If correction of the MI was less than 90% of the pre-operative MI, the OR for re-displacement was 4.6 (p = 0.03). Age at the time of surgery, GMFCS, pelvic obliquity and scoliosis were not predictive of re-displacement. These results, firstly, highlight the importance of hip surveillance in children with cerebral palsy to allow timely intervention to ensure adequate radiological outcomes. Secondly, as in developmental hip dysplasia, full concentric reduction is essential to reduce the risk of re-displacement, with its associated clinical consequences

Aim:. An assessment of the relationship between pathological Developmental Dysplasia of the Hip (DDH) and Congenital Talipes Equinovarus (CTEV). Introduction:. Traditional UK guidelines consider abnormalities of the foot to be a risk factor for DDH. 1,2. Currently, there is controversy whether congenital foot abnormalities are true risk factors for pathological DDH. 3,4. There is a relationship between CTCV and hip dysplasia though the relationship between CTEV and pathological DDH is less clear. 5. In a previous 11 year prospective longitudinal study no case of Graf Types III, IV or irreducible hip dislocation were associated with CTEV. 5. Subsequent correspondence and case histories have challenged this view. 6. Methods:. In order to clarify this issue, a 20-year prospective longitudinal observational study was undertaken. All cases of fixed CTEV (Harold & Walker types 1 to 3) referred to the sub-regional Paediatric Orthopaedic clinic at the Royal Blackburn Hospital were evaluated, the feet and hips clinically assessed (Ortolani & Barlow manoeuvres) and the hips ultra-sounded by the senior author (RWP). Modified Graf and Harcke hip ultrasound classification systems were employed. Graf Type III, IV and irreducible hip dislocation were considered pathological. Results:. The incidence of CTEV was 1.46 per 1000 live births (nationally quoted incidence of 1 to 2 per 1000 live births. 7. ). There was one case of Graf Type III dysplasia with no cases of clinical hip instability. Currently, the clinical significance of this type of dysplasia is uncertain. There were no cases of Graf Type IV dislocations or radiological irreducible hip dislocation. Conclusion:. Fixed CTEV should not be considered as a risk factor for pathological DDH and routine sonographic hip screening of CTEV should not be advocated. This is supportive evidence for the current English NIPE guidelines in which the only risk factors screened are family history and breech presentation. Level of evidence: II

Aims. We aimed to examine the true incidence of DDH in our area, and to investigate both known and unknown risk factors for the condition. Methods. Data were prospectively recorded on all live births in the Exeter area from January 1998 to December 2008. The data included the baby's gestational age, sex, demographic details of parents, maternal age and parity, geographic and socioeconomic data, mode of presentation and delivery, and family history of DDH. Data were also collected prospectively on all treated cases of DDH (Graf 2c and above) for the same period. Using the population live birth data as controls, odds ratios (OR) and confidence intervals were calculated. Results. The incidence of DDH in our area was 4.9 per 1000 live births. Although this might have been influenced by selective ultrasound screening, our records show that 74% of our cases had a Graf 3 or Graf 4 hip or presented late, and thus they would arguably have presented with or without screening. The remaining 26% had significant dysplasia (Graf 2c) with or without instability. Female sex (OR 7.3, 4.5-10.1), primiparity (OR 3.6, 2.3-5.6), positive family history (OR 12.6, 8.9-17.8) and breech presentation (OR 8.6, 6.1-12.1) were confirmed as risk factors for DDH. Caesarian section was protective in both cephalic (reduction in OR 0.5) and breech (reduction in OR 2.3) presentations. Postmaturity increased the chance of DDH (OR 2.7, 1.9-3.9). Certain postcodes also had significantly higher incidences (up to 11 per 1000 births), and these areas scored higher on an index of social deprivation. Birth weight, head circumference, and maternal blood group had no significant effects. Conclusions. Incidence in our area was higher than is usually quoted. Our data suggest that there are geographical variations in the condition's incidence. We identified novel risk factors that warrant further investigation

Between May 1992 and April 1997, there were 20 452 births in the Blackburn District. In the same period 1107 infants with hip ‘at-risk’ factors were screened prospectively by ultrasound. We recorded the presence of dislocation and dysplasia detected under the age of six months using Graf’s alpha angle. Early dislocation was present in 36 hips (34 dislocatable and 2 irreducible). Of the 36 unstable hips, 30 (83%) were referred as being Ortolani-positive or unstable; 25 (69%) of these had at least one of the risk factors. Only 11 (31%) were identified from the ‘at-risk’ screening programme alone (0.54 per 1000 live births). Eight cases of ‘late’ dislocation presented after the age of six months (0.39 per 1000 live births). The overall rate of dislocation was 2.2 per 1000 live births. Only 31% of the dislocated hips belonged to a major ‘at-risk’ group. Statistical analysis confirmed that the risk factors had a relatively poor predictive value if used as a screening test for dislocation. In infants referred for doubtful clinical instability, one dislocation was detected for every 11 infants screened (95% confidence interval (CI) 8 to 17) whereas in infants referred because of the presence of any of the major ‘at-risk’ factors the rate was one in 75 (95% CI 42 to 149). Routine ultrasound screening of the ‘at-risk’ groups on their own is of little value in significantly reducing the rate of ‘late’ dislocation in DDH, but screening clinically unstable hips alone or associated with ‘at-risk’ factors has a high rate of detection

Aim. In previous small series, some authors have suggested a difference between re-fractures through immature callus and remodelled bone. We aimed to determine whether different fracture patterns occur in early and late re-fractures of paediatric forearm bones. Methods. Notes and radiographs of 77 forearm re-fractures from children aged 2–14 years were retrieved from our institution's radiographic database. Children treated surgically at initial presentation and re-fractures beyond one year were excluded. A control group of 100 forearm fractures without complication was used for comparison. Statistical analysis used chi-square and unpaired t-tests and statistically significant results were based on a two-tailed p-value <0.05. Results. Boys (76%), left laterality (78%), radius (69%), initial greenstick (66%) and diaphyseal fractures (62%) were most common. 60% of re-fractures were complete, 27% greenstick and 13% buckle. Median time to re-fracture was 93 days. Compared with buckle/greenstick configurations, complete re-fractures were more likely to occur if the re-fracture occurred within 50 days of initial injury (84% vs. 52%; p<0.05), if residual angulation was present on the radiograph at the time of last follow-up before re-fracture (74% vs. 46%; p<0.05) and resulted in a trend towards surgical management (25% vs 10%). A five-week period in cast was used to stratify children in both re-fracture and control groups. The re-fracture group was more likely to have been in cast for less than five weeks when compared to the control group (54% vs. 38%; p<0.05). Conclusions. Reduced length of cast immobilisation may be associated with an increased risk of re-fracture. Residual deformity before re-fracture and early re-fractures were more likely to result in complete re-fractures which may also mean a greater chance of surgical management

We analysed retrospectively the risk factors leading to femoral overgrowth after flexible intramedullary nailing in 43 children (mean age 7.1 years (3.6 to 12.0)) with fractures of the shaft of the femur. We reviewed their demographic data, mechanism of injury, associated injuries, the type and location of the fractures, the nail–canal diameter (NCD) ratios and femoral overgrowth at a mean follow-up of 40.7 months (25.2 to 92.7). At that time, the children were divided into two groups, those with femoral overgrowth of < 1 cm (Group 1), and those with overgrowth of ≥ 1 cm (Group 2). The mean femoral overgrowth of all patients was 0.6 cm at final follow-up. Overgrowth of ≥ 1 cm was noted in 11 children (25.6%). The NCD ratio was significantly lower in Group 2 than in Group 1, with an odds ratio of 30.0 (p = 0.003). We believe that a low NCD ratio is an indicator of an unstable configuration with flexible intramedullary nailing, and have identified an association between a low NCD ratio and femoral overgrowth resulting in leg-length discrepancy after flexible intramedullary nailing in paediatric femoral shaft fractures. Cite this article: Bone Joint J 2013;95-B:254–8

Aims. The aim of this study was to describe the incidence of refractures among children, following fractures of all long bones, and to identify when the risk of refracture decreases. Methods. All patients aged under 16 years with a fracture that had occurred in a bone with ongoing growth (open physis) from 1 May 2015 to 31 December 2020 were retrieved from the Swedish Fracture Register. A new fracture in the same segment within one year of the primary fracture was regarded as a refracture. Fracture localization, sex, lateral distribution, and time from primary fracture to refracture were analyzed for all long bones. Results. Of 40,090 primary fractures, 348 children (0.88%) sustained a refracture in the same long bone segment. The diaphyseal forearm was the long bone segment most commonly affected by refractures (n = 140; 3.4%). The median time to refracture was 147 days (interquartile range 82 to 253) in all segments of the long bones combined. The majority of the refractures occurred in boys (n = 236; 67%), and the left side was the most common side to refracture (n = 220; 62%). The data in this study suggest that the risk of refracture decreases after 180 days in the diaphyseal forearm, after 90 days in the distal forearm, and after 135 days in the diaphyseal tibia. Conclusion. Refractures in children are rare. However, different fractured segments run a different threat of refracture, with the highest risk associated with diaphyseal forearm fractures. The data in this study imply that children who have sustained a distal forearm fracture should avoid hazardous activities for three months, while children with a diaphyseal forearm fracture should avoid these activities for six months, and for four and a half months if they have sustained a diaphyseal tibia fracture. Cite this article: Bone Joint J 2023;105-B(8):928–934

Aims. The Uppföljningsprogram för cerebral pares (CPUP) Hip Score distinguishes between children with cerebral palsy (CP) at different levels of risk for displacement of the hip. The score was constructed using data from Swedish children with CP, but has not been confirmed in any other population. The aim of this study was to determine the calibration and discriminatory accuracy of this score in children with CP in Scotland. Methods. This was a total population-based study of children registered with the Cerebral Palsy Integrated Pathway Scotland. Displacement of the hip was defined as a migration percentage (MP) of > 40%. Inclusion criteria were children in Gross Motor Function Classification System (GMFCS) levels III to V. The calibration slope was estimated and Kaplan-Meier curves produced for five strata of CPUP scores to compare the observed with the predicted risk of displacement of the hip at five years. For discriminatory accuracy, the time-dependent area under the receiver operating characteristic curve (AUC) was estimated. In order to analyze differences in the performance of the score between cohorts, score weights, and subsequently the AUC, were re-estimated using the variables of the original score: the child’s age at the first examination, GMFCS level, head shaft angle, and MP of the worst hip in a logistic regression with imputation of outcomes for those with incomplete follow-up. Results. The discriminatory accuracy of the score in the new population of 367 children was high (AUC 0.78 (95% confidence interval (CI) 0.71 to 0.86)). The calibration of the score was insufficient (slope 0.48 (95% CI 0.31 to 0.65)), and the absolute risks of displacement of the hip in this population were overestimated. The AUC increased with re-estimated weights (0.85 (95% CI 0.79 to 0.91)). Conclusion. The CPUP Hip Score had a high ability to discriminate between children at different levels of risk for displacement of the hip. The score overestimated the absolute risks of displacement in this population, which may have resulted from differences in the way children were initially registered in the two programmes. The results are promising, but the score weights may need re-estimation before its clinical application in Scotland. Cite this article: Bone Joint J 2022;104-B(5):640–644

Aims. The aim of this study was to inform the epidemiology and treatment of slipped capital femoral epiphysis (SCFE). Methods. This was an anonymized comprehensive cohort study, with a nested consented cohort, following the the Idea, Development, Exploration, Assessment, Long-term study (IDEAL) framework. A total of 143 of 144 hospitals treating SCFE in Great Britain participated over an 18-month period. Patients were cross-checked against national administrative data and potential missing patients were identified. Clinician-reported outcomes were collected until two years. Patient-reported outcome measures (PROMs) were collected for a subset of participants. Results. A total of 486 children (513 hips) were newly affected, with a median of two patients (interquartile range 0 to 4) per hospital. The annual incidence was 3.34 (95% confidence interval (CI) 3.01 to 3.67) per 100,000 six- to 18-year-olds. Time to diagnosis in stable disease was increased in severe deformity. There was considerable variation in surgical strategy among those unable to walk at diagnosis (66 urgent surgery vs 43 surgery after interval delay), those with severe radiological deformity (34 fixation with deformity correction vs 36 without correction) and those with unaffected opposite hips (120 prophylactic fixation vs 286 no fixation). Independent risk factors for avascular necrosis (AVN) were the inability of the child to walk at presentation to hospital (adjusted odds ratio (aOR) 4.4 (95% CI 1.7 to 11.4)) and surgical technique of open reduction and internal fixation (aOR 7.5 (95% CI 2.4 to 23.2)). Overall, 33 unaffected untreated opposite hips (11.5%) were treated for SCFE by two-year follow-up. Age was the only independent risk factor for contralateral SCFE, with age under 12.5 years the optimal cut-off to define ‘at risk’. Of hips treated with prophylactic fixation, none had SCFE, though complications included femoral fracture, AVN, and revision surgery. PROMs demonstrated the marked impact on quality of life on the child because of SCFE. Conclusion. The experience of individual hospitals is limited and mechanisms to consolidate learning may enhance care. Diagnostic delays were common and radiological severity worsened with increasing time to diagnosis. There was unexplained variation in treatment, some of which exposes children to significant risks that should be evaluated through randomized controlled trials. Cite this article: Bone Joint J 2022;104-B(4):519–528