Outcomes after slipped capital femoral epiphysis: a population-based study with three-year follow-up.

PURPOSE: To evaluate outcomes three years after treatment for slipped capital femoral epiphysis (SCFE): development of avascular necrosis (AVN), subsequent surgery, hip function and the contralateral hip. METHODS: This prospective cohort study included a total national population of 379 children treated for SCFE between 2007 and 2013. A total of 449 hips treated for SCFE and 151 hips treated with a prophylactic fixation were identified. The Barnhöft questionnaire, a valid patient-reported outcome measure (PROM), was used. RESULTS: In all, 90 hips had a severe slip, 61 of these were clinically unstable. AVN developed in 25 of the 449 hips. Six of 15 hips treated with capital realignment developed AVN. A peri-implant femur fracture occurred in three slipped hips and in two prophylactically pinned hips. In three of these five hips technical difficulties during surgery was identified. In 43 of 201 hips scheduled for regular follow-up a subsequent SCFE developed in the contralateral hip. Implant extraction after physeal closure was performed in 156 of 449 hips treated for SCFE and in 51 of 151 prophylactically fixed hips. Children with impaired hip function could be identified using the Barnhöft questionnaire. CONCLUSION: Fixation in situ is justified to remain as the primary treatment of choice in SCFE. Overweight is more common in children with SCFE than in the average population. Prophylactic fixation is a safe procedure when performed using a correct technique. The number of patients who developed AVN after capital realignment is of concern. We recommend rigorous follow-up of both hips, including PROM evaluation, until physeal closure. LEVEL OF EVIDENCE: II - prospective cohort study.

The head shaft angle is associated with hip displacement in children at GMFCS levels III-V - a population based study.

BACKGROUND: An increased Head Shaft Angle (HSA) has been reported as a risk factor for hip displacement in children with cerebral palsy (CP) but opinions differ in the literature. The purpose of this study was to re-evaluate the relationship between HSA and hip displacement in a different population of children with CP. METHODS: The Cerebral Palsy Integrated Pathway Scotland surveillance programme includes 95% of all children with CP in Scotland. The pelvic radiographs from 640 children in GMFCS levels III-V were chosen. The most displaced hip was analysed and the radiographs used were those taken at the child's first registration in the database to avoid the potential effects of surveillance on subsequent hip centration. A logistic regression model was used with hip displacement (migration percentage [MP] ≥40%) as outcome and HSA, GMFCS, age and sex as covariates. RESULTS: The MP was ≥40% in 118 hips with a mean HSA of 164° (range 121-180°) and < 40% in 522 hips with a mean HSA of 160° (range 111-180°). The logistic regression analysis showed no significant influence of age and sex on MP in this population but a high GMFCS level was strongly associated with hip displacement. An increased HSA was also associated with hip displacement, a 10° difference in HSA for children adjusted for age, sex, and GMFCS gave an odds ratio of 1.26 for hip displacement equal or above 40% (p = 0.009) and hips with HSA above 164.5 degrees had an odds ratio of 1.96 compared with hips with HSA below 164.5 degrees (p = 0.002). CONCLUSION: These findings confirm that HSA is associated with hip displacement in children in GMFCS levels III-V.

Inter- and intra-rater reliability of the head-shaft angle in children with cerebral palsy.

PURPOSE: Children with cerebral palsy (CP) are at increased risk for hip dislocation. This can be prevented in most cases using surveillance programmes that include radiographic examinations. Known risk factors for hip dislocation include young age, high Gross Motor Function Classification System (GMFCS) level and high migration percentage (MP). The head-shaft angle (HSA) has recently been described as an additional risk factor. The study aim was to determine inter- and intra-rater reliability of the HSA in a surveillance programme for children with CP. METHODS: We included hip radiographs from the CP surveillance programme CPUP in southern Sweden during the first half of 2016. Fifty radiographs were included from children at GMFCS levels II-V, with a mean age of 6.6 (SD 3.2) years. Three raters measured the HSA of one hip (left or right) at baseline and four weeks later; intraclass correlation coefficient (ICC) was used to estimate inter- and intra-rater reliability. RESULTS: Inter- and intra-rater reliability were excellent for the HSA, with ICC 0.92 (95% CI 0.87-0.96) and ICC 0.99 (95% CI 0.98-0.99), respectively. CONCLUSION: The HSA showed excellent inter- and intra-rater reliability for children with CP, providing further evidence for use of the HSA as an additional factor for identifying risk for further hip displacement or dislocation.

Pinning the slipped and contralateral hips in the treatment of slipped capital femoral epiphysis.

PURPOSE: To describe and comment on the treatment of the slipped capital femoral epiphysis (SCFE) with pinning and to present the pros and cons of prophylactic pinning of the contralateral hip. SUMMARY: Pinning the SCFE aims to fix the epiphysis and prevent further slipping. Some devices allow for further growth and remodeling of the femoral neck post-operatively. This results in maintained femoral offset and probably reduced risk of femoroacetabular impingement. There are currently no long-term follow-up studies showing less complications or better function than after in situ fixation. The contralateral hip can be managed by prophylactic pinning or close follow-up with repeated radiographic examinations. Which of the methods is best is still controversial due to different opinions on the risk of bilateral SCFE, the consequences of a later contralateral slip and the risks of prophylactic pinning. Although research supports prophylactic pinning the child and the family's preference is crucial.

Prediction of hip displacement in children with cerebral palsy: development of the CPUP hip score.

Hip displacement, defined in this study as a migration percentage (MP) of more than 40%, is a common, debilitating complication of cerebral palsy (CP). In this prospective study we analysed the risk of developing hip displacement within five years of the first pelvic radiograph. All children with CP in southern and western Sweden are invited to register in the hip surveillance programme CPUP. Inclusion criteria for the two groups in this study were children from the CPUP database born between 1994 and 2009 with Gross Motor Function Classification System (GMFCS) III to V. Group 1 included children who developed hip displacement, group 2 included children who did not develop hip displacement over a minimum follow-up of five years. A total of 145 children were included with a mean age at their initial pelvic radiograph of 3.5 years (0.6 to 9.7). The odds ratio for hip displacement was calculated for GMFCS-level, age and initial MP and head-shaft angle. A risk score was constructed with these variables using multiple logistic regression analysis. The predictive ability of the risk score was evaluated using the area under the receiver operating characteristics curve (AUC). All variables had a significant effect on the risk of a MP > 40%. The discriminatory accuracy of the CPUP hip score is high (AUC = 0.87), indicating a high ability to differentiate between high- and low-risk individuals for hip displacement. The CPUP hip score may be useful in deciding on further follow-up and treatment in children with CP.

Prevention of dislocation of the hip in children with cerebral palsy: 20-year results of a population-based prevention programme.

In 1994 a cerebral palsy (CP) register and healthcare programme was established in southern Sweden with the primary aim of preventing dislocation of the hip in these children. The results from the first ten years were published in 2005 and showed a decrease in the incidence of dislocation of the hip, from 8% in a historical control group of 103 children born between 1990 and 1991 to 0.5% in a group of 258 children born between 1992 and 1997. These two cohorts have now been re-evaluated and an additional group of 431 children born between 1998 and 2007 has been added. By 1 January 2014, nine children in the control group, two in the first study group and none in the second study group had developed a dislocated hip (p < 0.001). The two children in the first study group who developed a dislocated hip were too unwell to undergo preventive surgery. Every child with a dislocated hip reported severe pain, at least periodically, and four underwent salvage surgery. Of the 689 children in the study groups, 91 (13%) underwent preventive surgery. A population-based hip surveillance programme enables the early identification and preventive treatment, which can result in a significantly lower incidence of dislocation of the hip in children with CP.

Sex differences in cerebral palsy incidence and functional ability: a total population study.

AIM: To describe gender difference in a total population of children with cerebral palsy (CP), related to subtype, gross and fine motor function, and to compare CP incidence trends in girls and boys. METHODS: All 590 children with CP born in southern Sweden 1990-2005 were included. CP subtype was classified according to the Surveillance of Cerebral Palsy in Europe, gross motor function according to Gross Motor Function Classification System (GMFCS) and manual ability according to Manual Ability Classification System (MACS). Trends in CP incidence by birth year were analysed using Poisson regression modelling. RESULTS: There was a male predominance in all levels of GMFCS except level II, in all levels of MACS and in all CP subtypes except ataxic CP. There was no statistically significant difference between males and females regarding gross motor function or manual ability. The CP incidence trends in boys compared with girls did not change during the period 1990-2005. CONCLUSION: No equalization was detected in the incidence of CP between girls and boys during recent years in this total population. We could not confirm any consistent sex difference in motor function levels. Male sex is a risk factor for CP.

Hip surveillance and management of the displaced hip in cerebral palsy.

INTRODUCTION: This article provides an overview of the management of a displaced hip in children with cerebral palsy and considers surveillance programmes, principles of surgical reconstruction and options for the salvage of an unreconstructable hip in these children. CONCLUSION: Hip dislocation in CP is potentially preventable if children are included from an early age in a surveillance programme that includes repeat radiographic and clinical examinations, and preventive treatment for hips that are displacing. A surveillance programme should be based on the child's age, GMFCS level and migration percentage (MP), and surgical prevention may be considered in children with a MP exceeding 33 %.

Linoleic acid, a dietary n-6 polyunsaturated fatty acid, and the aetiology of ulcerative colitis: a nested case-control study within a European prospective cohort study.

OBJECTIVE: Dietary linoleic acid, an n-6 polyunsaturated fatty acid, is metabolised to arachidonic acid, a component of colonocyte membranes. Metabolites of arachidonic acid have pro-inflammatory properties and are increased in the mucosa of patients with ulcerative colitis. The aim of this investigation was to conduct the first prospective cohort study investigating if a high dietary intake of linoleic acid increases the risk of developing incident ulcerative colitis. DESIGN AND SETTING: Dietary data from food frequency questionnaires were available for 203 193 men and women aged 30-74 years, resident in the UK, Sweden, Denmark, Germany or Italy and participating in a prospective cohort study, the European Prospective Investigation into Cancer and Nutrition (EPIC). These participants were followed up for the diagnosis of ulcerative colitis. Each case was matched with four controls and the risk of disease calculated by quartile of intake of linoleic acid adjusted for gender, age, smoking, total energy intake and centre. RESULTS: A total of 126 participants developed ulcerative colitis (47% women) after a median follow-up of 4.0 years (range, 1.7-11.3 years). The highest quartile of intake of linoleic acid was associated with an increased risk of ulcerative colitis (odds ratio (OR) = 2.49, 95% confidence interval (CI) = 1.23 to 5.07, p = 0.01) with a significant trend across quartiles (OR = 1.32 per quartile increase, 95% CI = 1.04 to 1.66, p = 0.02 for trend). CONCLUSIONS: The data support a role for dietary linoleic acid in the aetiology of ulcerative colitis. An estimated 30% of cases could be attributed to having dietary intakes higher than the lowest quartile of linoleic acid intake.

Hand function in cerebral palsy. Report of 367 children in a population-based longitudinal health care program.

PURPOSE: To describe aspects of hand function in a total population of children with cerebral palsy (CP). METHODS: Upper extremity data were collected for 367 children who were born between 1992 and 2001 and were registered in a population-based health care program for children with CP. Hand function was classified according to the Manual Ability Classification System (MACS), the House functional classification, and the Zancolli classification. The type of spastic thumb-in-palm deformity was evaluated according to House. RESULTS: In the total population of children with CP aged 4 to 14 years, 60% had more than minor problems with hand function (>MACS I). Independence in age-relevant, daily manual activities (MACS I-II) was noted in 87% of children with spastic unilateral CP and in 63% of children with spastic bilateral CP, but in only 20% of children with dyskinetic CP. According to the House functional classification, both hands were spontaneously and independently used in 55% of children (House 7-8), whereas 5% did not use either of their hands (House 0). Minor increase of flexor muscle tone (Zancolli level 1) was found in 69% of all children. Only 2% were in level 3 in both hands. Spastic thumb-in-palm deformity in 1 hand was found in 25% and in both hands in another 15%. CONCLUSIONS: Limitations in hand function are common in all types of CP, but characteristics of the disability vary considerably between different CP subtypes. The MACS classification is useful to evaluate how well children can handle objects in daily activities. The House functional classification describes grip function in each hand separately; the Zancolli classification of finger and wrist extension and the classification of thumb-in-palm deformity according to House give an estimate of dynamic spasticity. All these classifications were shown to be useful in a population-based health care program, but further studies of the psychometric properties are required.

Radiostereometric analysis for monitoring percutaneous physiodesis. A preliminary study.

Percutaneous physiodesis is an established technique for treating mild leg-length discrepancy and problems of expected extreme height. Angular deformities resulting from incomplete physeal arrest have been reported, and little is known about the time interval from percutaneous physiodesis to actual physeal arrest. This procedure was carried out in ten children, six with leg-length discrepancy and four with expected extreme height. Radiostereometric analysis was used to determine the three-dimensional dynamics of growth retardation. Errors of measurement of translation were less than 0.05 mm and of rotation less than 0.06 degrees. Physeal arrest was obtained in all but one child within 12 weeks after physiodesis and no clinically-relevant angular deformities occurred. This is a suitable method for following up patients after percutaneous physiodesis. Incomplete physeal arrest can be detected at an early stage and the procedure repeated before corrective osteotomy is required.

Prevention of dislocation of the hip in children with cerebral palsy. The first ten years of a population-based prevention programme.

In 1994, a register for cerebral palsy and a health-care programme were started in southern Sweden with the aim of preventing dislocation of the hip in children with cerebral palsy. It involved all children with cerebral palsy born in 1992 or later. None of the 206 affected children born between 1992 and 1997 has developed a dislocation following the introduction of the prevention programme. Another 48 children moved into the area and none developed any further dislocation. Of the 251 children with cerebral palsy, aged between five and 11 years, living in the area on January 1, 2003, only two had a dislocated hip. One boy had moved into the area at age of nine with a dislocation and a girl whose parents chose not to participate in the programme developed bilateral dislocation. One boy, whose condition was considered to be too poor for preventative surgery, developed a painful dislocation of the hip at the age of five years and died three years later. Eight of 103 children in a control group, consisting of all children with cerebral palsy living in the area between 1994 and 2002, and born between 1990 and 1991, developed a dislocation of the hip before the age of six years. The decreased incidence of dislocation after the introduction of the prevention programme was significant (p < 0.001). Dislocation of the hip in cerebral palsy remains a serious problem, and prevention is important. Our screening programme and early intervention when lateral displacement of the femoral head was detected appear to be successful.

Cerebral palsy in southern Sweden I. Prevalence and clinical features.

UNLABELLED: The prevalence, clinical features and gross motor function of children with cerebral palsy in southern Sweden were investigated. The study covered the birth year period 1990-1993, during which 65,514 livebirths were recorded in the area. On the census date (1 January 1998), 68366 children born in 1990-1993 lived in the area. The study comprised 167 children, 145 of them born in Sweden and 22 born abroad. The livebirth prevalence was 2.2 per 1,000, and the prevalence including children born abroad was 2.4 per 1,000. The distribution according to gestational age, birthweight and subdiagnoses was similar to that in earlier Swedish studies, except for a higher rate of dyskinetic syndromes in this study. CONCLUSION: The point prevalence of cerebral palsy was 2.4 and the livebirth prevalence was 2.2. Children born abroad had a higher prevalence and were more often severely disabled. Severe disability was often combined with associated impairments such as mental retardation, epilepsy and visual impairment.

Cerebral palsy in southern Sweden II. Gross motor function and disabilities.

UNLABELLED: The gross motor function and disabilities in children with cerebral palsy in southern Sweden were investigated and related to clinical features. The study covered the birth year period 1990-1993 and comprised 167 children, 145 of them born in Sweden and 22 born abroad. The clinical features and gross motor function were analysed at a mean age of 6.8 y. Clinical features were obtained from a continuing healthcare follow-up programme. Gross motor function was classified according to the Gross Motor Function Classification System (GMFCS). Walking independently was possible for 86% of the hemiplegic, 63% of the pure ataxic, 61% of the diplegic and 21% of the dyskinetic children. None of the tetraplegic children was able to walk. The classification of gross motor function revealed that 59% of the children were categorized into levels I and II (mildly disabled), 14% into level III (moderately disabled) and 27% into levels IV and V (severely disabled). Children born abroad were more severely disabled. CONCLUSION: The standardized age-related classification system GMFCS enabled a specific description of gross motor function in relation to clinical features. Significant differences between GMFCS levels and subgroups of diagnosis, aetiology. intellectual capacity, epilepsy and visual impairment were found.

Assessment of primary hip osteoarthritis: comparison of radiographic methods using colon radiographs.

OBJECTIVE: To compare the reliability of quantitative measurement of minimum hip joint space with a qualitative global assessment of radiological features for estimating the prevalence of primary osteoarthritis (OA) of the hip in colon radiographs. METHODS: All colon radiographs from patients aged 35 or older, taken at three different radiographic departments in Iceland during the years 1990-96, were examined. A total of 3002 hips in 638 men and 863 women were analysed. Intraobserver and interobserver reliability was assessed by measuring 147 randomly selected radiographs (294 hips) twice by the same observer, and 87 and 98 randomly selected radiographs (174 and 196 hips) by two additional independent observers. Minimum hip joint space was measured with a millimetre ruler, and global assessment of radiological features by a published atlas. RESULTS: With a minimum joint space of 2.5 mm or less as definition for OA, 212 hips were defined as having OA. When the global Kellgren and Lawrence assessment with grade 2 (definite narrowing in the presence of definite osteophytes) or higher as definition for OA was used, 202 hips showed OA. However, only 166 hips were diagnosed as OA with both systems. With 2.0 or 3.0 mm minimum joint space as cut off point, the difference between the two methods increased. Both intrarater and interrater reliability was significantly higher with joint space measurement than with global assessment. CONCLUSIONS: Overall prevalence of radiological OA was similar with the two methods. However, the quantitative measurement of minimum hip joint space had a better within-observer and between-observer reliability than qualitative global assessment of radiographic features of hip OA. It is thus suggested that minimum joint space measurement is a preferable method in epidemiological studies of radiological hip OA.

Comparison of the Gross Motor Function Measure and Paediatric Evaluation of Disability Inventory in assessing motor function in children undergoing selective dorsal rhizotomy.

This study was designed to compare assessment with the functional outcome measures Gross Motor Function Measure (GMFM) and Pediatric Evaluation of Disability Inventory (PEDI) over time, in children with cerebral palsy (CP) undergoing selective dorsal rhizotomy combined with individualised physiotherapeutic interventions. Using the Gross Motor Function Classification System (GMFCS), 18 children with spastic diplegia were divided into two groups according to age-related severity of motor function impairment. Data were collected preoperatively, and at 6 and 12 months postoperatively. Both instruments were sensitive to changes in function over time in the series as a whole and in the group with milder impairment, although the PEDI detected significant changes earlier. In the group with more severe impairment, changes in function were detected only with the PEDI, not with the GMFM. Thus, the instruments are to be considered complementary tests, because they measure different aspects of function.

Incidence of total hip replacement for primary osteoarthrosis in Iceland 1982-1996.

We report the incidence of total hip replacements performed in Iceland between 1982 and 1996. During this period, 3,403 hip arthroplasties were done. The annual number of procedures increased from 94 hips in 1982 to 323 hips in 1996. Annual rates of total hip replacements due to primary osteoarthrosis per 10(5) inhabitants were 68 in 1982-1986, 90 in 1987-1991, and 114 in 1992-1996. In the years 1992-1996, the age-standardized incidence of total hip replacements for primary osteoarthrosis was 3/10(5) among patients younger than 39 years of age, while it was 621/10(5) among those 70-79 years of age. The mean age at surgery for primary osteoarthrosis was 69 years in both men and women. Incidence rates in various countries are difficult to compare, but by using age-standardized data and correction for differences in population structures between Iceland and Sweden, we find that the incidence of total hip replacement for primary osteoarthrosis of the hip is at least 50% higher in Iceland than in Sweden. This difference is consistent with the higher prevalence of hip osteoarthrosis observed in Iceland than in Sweden.

The American Paediatric Evaluation of Disability Inventory (PEDI). Applicability of PEDI in Sweden for children aged 2.0-6.9 years.

The American Paediatric Evaluation of Disability Inventory (PEDI) is a new instrument for evaluating functional performance in disabled children aged 6 months to 7.5 years. It was developed to determine a child's functional capacity and performance in three domains, self-care, mobility and social function, as reflected in scores on three scales: (i) functional skills (current capability in specific tasks), (ii) caregiver assistance (i.e. provided to facilitate the child's performance), and (iii) modifications (i.e. environmental or technical modifications needed to facilitate the child's function). The present study was designed to compare results obtained using the PEDI in a Swedish sample with the American normative data, and to analyse the content and relevance of PEDI items for use in Sweden. The PEDI was administered as a questionnaire in structured interview form to the parents of 52 non-disabled Swedish children aged 2.0-6.9 years, divided into ten age groups. Correlation analysis (Pearson's r) showed scores for the Swedish sample to manifest strong correlation with the respective American normative data, both for the functional skills (r = 0.90-0.98) and caregiver assistance (r = 0.93-0.99) scales, respectively. Scores for the modification scale were not compared. Thus, the results suggest the American normative data to be appropriate for reference purposes in Sweden.

Prevalence of hip osteoarthritis in Iceland.

OBJECTIVE: To assess the prevalence of primary hip osteoarthritis (OA) in Iceland. To compare the prevalence of primary hip OA in Iceland with published rates of primary hip OA for related Scandinavian populations. METHODS: Roentgenographs were examined of 1530 Icelandic people 35 years or older (653 males, 877 females) subjected to colon radiography during the years 1990-1996. The radiographs examined represent approximately 40% of all colon radiographs taken in Iceland during this period. After exclusion of non-primary hip OA cases, the minimum hip joint space was measured with a mm ruler. Presence of hip OA was defined as a minimum joint space of 2.5 mm or less on an anteroposterior radiograph. Intraclass correlation coefficients for inter and intraobserver variability of assessment of mm joint space were 0.91 and 0.95, respectively. RESULTS: Of the 1517 people included, 227 hips in 165 patients (77 men, 88 women) were diagnosed as having radiological primary hip OA. The mean age at colon examination for these patients was 68 (35-89) years. The overall prevalence of coxarthrosis among all examined patients 35 years and older was 10.8% (12% for men, 10% for women), rising from 2% at 35-39 years to 35.4% for those 85 years or older. If the population structure (age and sex distribution) for those older than 35 years in Iceland was used to standardise prevalence for both Iceland and south Sweden (using previously published data for south Sweden), the age and sex standardised prevalence of hip OA for those older than 35 years in Iceland was 8%, compared with 1.2% for south Sweden. CONCLUSIONS: The prevalence of radiological primary hip OA is very high in Iceland, and in excess of fivefold higher than the prevalence found by using similar techniques in studies on related populations in southern Scandinavia. The rate difference is particularly notable for those younger than 70 years.