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Aims To determine the likelihood of achieving a successful closed reduction (CR) of a dislocated hip in developmental dysplasia of the hip (DDH) after failed Pavlik harness treatment We report the rate of avascular necrosis (AVN) and the need for further surgical procedures. Methods Data was obtained from the Northern Ireland DDH database. All children who underwent an attempted closed reduction between 2011 and 2016 were identified. Children with a dislocated hip that failed Pavlik harness treatment were included in the study. Successful closed reduction was defined as a hip that reduced in theatre and remained reduced. Most recent imaging was assessed for the presence of AVN using the Kalamchi and MacEwen classification. Results There were 644 dislocated hips in 543 patients initially treated in Pavlik harness. In all, 67 hips failed Pavlik harness treatment and proceeded to arthrogram (CR) under general anaesthetic at an average age of 180 days. The number of hips that were deemed reduced in theatre was 46 of the 67 (69%). A total of 11 hips re-dislocated and underwent open reduction, giving a true successful CR rate of 52%. For the total cohort of 67 hips that went to theatre for arthrogram and attempted CR, five (7%) developed clinically significant AVN at an average follow-up of four years and one month, while none of the 35 hips whose reduction was truly successful developed clinically significant AVN. Conclusion The likelihood of a successful closed reduction of a dislocated hip in the Northern Ireland population, which has failed Pavlik harness treatment, is 52% with a clinically significant AVN rate of 7%. As such, we continue to advocate closed reduction under general anaesthetic for the hip that has failed Pavlik harness. Cite this article: Bone Jt Open 2021;2(8):594–598.

AimsTo monitor the performance of services for developmental dysplasia of the hip (DDH) in Northern Ireland and identify potential improvements to enhance quality of service and plan for the future.MethodsThis was a prospective observational study, involving all infants treated for DDH between 2011 and 2017. Children underwent clinical assessment and radiological investigation as per the regional surveillance policy. The regional radiology data was interrogated to quantify the use of ultrasound and ionizing radiation for this population.ResultsEvidence-based changes were made to the Northern Ireland screening programme, including an increase in ultrasound scanning capacity and expansion of nurse-led screening clinics. The number of infant hip ultrasound scans increased from 4,788 in 2011, to approximately 7,000 in 2013 and subsequent years. The number of hip radiographs on infants of less than one year of age fell from 7,381 to 2,208 per year. There was a modest increase in the treatment rate from 10.9 to 14.3 per 1,000 live births but there was a significant reduction in the number of closed hip reductions. The incidence of infants diagnosed with DDH after one year of age was 0.30 per 1,000 live births over the entire period.ConclusionImproving compliance with the regional infant hip screening protocols led to reduction in operative procedures and reduced the number of pelvic radiographs of infants. We conclude that performance monitoring of screening programmes for DDH is essential to provide a quality service. Cite this article: Bone Joint J 2020;102-B(4):495–500.

Background Legg-Calve-Perthes' disease (LCPD) is an idiopathic disease of the femoral head affecting the pediatric population. The causative factors remains poorly understood and it is associated with significant hip pathology in adult life. Research has demonstrated wide geographical variation in the incidence rates of LCPD with a relatively high incidence occurring in Northern Ireland (NI) shown in a previous study of incidence from the same unit. The number of new diagnoses of LCPD seems to be declining over time. This study aimed to track changes in the incidence of LCPD within the 0- to 14-year-old population over a 15-year period in NI. Methods An established database was utilized to collate information of any individual between the ages of 0 to 14 years with a diagnosis of LCPD. The data were compared with electronic radiologic records to confirm the diagnosis. Postal code data were used to the determine location of residence and used as a proxy measure of deprivation. Results The results of this epidemiological study have demonstrated a 61% decrease in the incidence of LCPD over a 15-year period within the pediatric population of NI. Comparison between 2 cohorts reveals no distinguishable change in distribution of age or sex. The relationship between geographical proxy measures of deprivation in NI and LCPD remains evident. Conclusions The number of new cases of LCPD is decreasing over time. The epidemiological data are unchanged between 2 cohorts over a 15-year period, and this therefore supports a change within the patients' environment relating to this decline. This change could relate to a number of factors including smoking rates, breastfeeding, lead use, and vaccination implementation. Level of evidence Level IV-retrospective cohort study.

BACKGROUND: Spastic hip subluxation or dislocation that is associated with an excessive coxa valga deformity is a common pathologic condition in children with cerebral palsy (CP) that is often treated with large bone reconstructive procedures. Guided growth techniques (such as stapling, plate, or transphyseal screw) have been widely used to alter the growth axis in patients with a lower-limb deformity but only a few reports have described their use in patients with coxa valga deformities. QUESTIONS/PURPOSES: (1) Does guided growth surgery using a transphyseal screw combined with adductor tenotomy prevent progressive coxa valga deformity and lateral hip subluxation in children with CP? (2) What factors influence the correction of coxa valga deformity and the success of hip stabilization? (3) What complications were associated with this operation and how often did children treated with it undergo reoperation? METHODS: From 2012 to 2016, at our institution, three authors (H-CH, KNK, K-WW) retrospectively studied data on children with CP who underwent guided growth of the hip for progressive bilateral hip subluxation associated with coxa valga deformities. A single percutaneous screw was inserted across the inferomedial portion of proximal femoral physis in an AP view and centered along femoral neck in lateral view under fluoroscopy guidance. During the period, we treated 25 consecutive children with CP who had progressive hip subluxation with coxa valga deformities. The indications for surgery were migration percentage > 30% and head-shaft angle > 155° with at least 2 years growth remaining. Of those, 13 patients underwent guided growth alone, and 48% (12) underwent a combination of guided growth and adductor tenotomy. Of the 25 patients treated with this approach, 96% (24) were available for follow-up with complete data at a minimum of 2 years follow-up (mean 50 months; range 25 to 72). All children (17 boys and seven girls; 48 hips) underwent surgery at a mean age of 8 years (range 5 to 12). With regard to the gross motor function classification system, three patients were Level 1, four patients were Level II, seven patients were Level III, seven were Level IV, and three were Level V. Radiographic parameters including the head-shaft angle, Hilgenreiner’s epiphyseal angle, acetabular index, and Reimer’s migration percentage were assessed before surgery and at the latest follow-up examination by one author (H-CH). Complications and reoperations were assessed by chart review. During the period in question, we generally offered secondary reconstructive surgery to patients who underwent a guided growth procedure once their subluxation progressed. RESULTS: With the data available, the coxa valga and lateral hip subluxation improved in terms of the reduction of head-shaft angle by a mean of 13° ± 7° (95% CI 11 to 15; p < 0.001) and the reduction of the migration percentage by 10% ± 11% (95% CI 7 to 13; p < 0.001). After controlling for potentially confounding variables like gender, gross motor function classification system, Hilgenreiner’s epiphyseal angle and acetabular index, we found that longer follow-up duration (r = 0.234; p < 0.001) and a smaller preoperative migration percentage (r = -0.258; p = 0.004) were associated with larger changes in the head-shaft angle. In terms of complications, we found that the proximal femoral physis grew off the screw tip in 44% (21 of 48 hips) at a mean of 28 months. Among these, 31% of hips (15 of 48) in 33% of patients (eight of 24) underwent replacement with a longer screw. Among the 17% of hips (eight of 48) in 21% of patients (five of 24) who had progressive lateral subluxation and underwent secondary reconstructive surgery, we found that their preoperative acetabular index was higher (mean 29° versus 21°; p < 0.001), as was their head-shaft angle (mean 166° versus 162°; p = 0.045), and migration percentage (mean 54% versus 36 %; p < 0.001). CONCLUSIONS: Although guided growth with single transphyseal screw did not create as large a degree of varus as proximal femoral osteotomy, it did stabilize the hip in children with cerebral palsy with migration percentage less than 50% in our series. It is a simple procedure that can be of benefit to children with cerebral palsy with unstable hip. Reoperation in patients where the physis has grown off the screw tip can be a problem; fortunately, it is a rather minor procedure to replace with a longer screw. LEVEL OF EVIDENCE: Level III, therapeutic study.

While passive range of motion (PROM) is commonly used to inform decisions on therapeutic management, knowledge of PROM of children with spastic cerebral palsy (CP) is limited. A population-based sample of 178 children with spastic CP (110 male; unilateral, n = 94; bilateral, n = 84; age range 4-17 years) and 68 typically developing children (24 male; age range 4-17 years) were recruited to the study. All children were able to walk a minimum of 10 m over a straight flat course, with or without assistive devices. Gross Motor Function Classification System (GMFCS) levels of participants with CP were: Level I = 55, Level II = 88, Level III = 21, and Level IV = 14. Ankle dorsiflexion, knee extension, popliteal angle, hip abduction, hip internal rotation, and hip external rotation were measured using a goniometer. The results indicate that the children with CP had significantly reduced PROM compared to the children with typical development. Children with CP demonstrated reduced length in the hamstrings, hip adductor, iliopsoas and gastrocnemius-soleus musculature, and contracture at the knee joint. Among children with CP, there were significant reductions in range with increasing functional limitation (higher GMFCS level) and variations based on unilateral or bilateral involvement. This was particularly the case for the hamstrings and hip adductor musculature, where PROM varied considerably across GMFCS Levels I to IV.

Developmental dysplasia of the hip (DDH) should be diagnosed as early as possible to optimise treatment. The current United Kingdom recommendations for the selective screening of DDH include a clinical examination at birth and at six weeks. In Northern Ireland babies continue to have an assessment by a health visitor at four months of age. As we continue to see late presentations of DDH, beyond one year of age, we hypothesised that a proportion had missed an opportunity for earlier diagnosis. We expect those who presented to our service with Tonnis grade III or IV hips and decreased abduction would have had clinical signs at their earlier assessments. We performed a retrospective review of all patients born in Northern Ireland between 2008 and 2010 who were diagnosed with DDH after their first birthday. There were 75 856 live births during the study period of whom 645 children were treated for DDH (8.5 per 1000). The minimum follow-up of our cohort from birth, to detect late presentation, was four years and six months. Of these, 32 children (33 hips) were diagnosed after their first birthday (0.42 per 1000). With optimum application of our selective screening programme 21 (65.6%) of these children had the potential for an earlier diagnosis, which would have reduced the incidence of late diagnosis to 0.14 per 1000. As we saw a peak in diagnosis between three and five months our findings support the continuation of the four month health visitor check. Our study adds further information to the debate regarding selective versus universal screening. Cite this article: Bone Joint J 2015;97-B:1572–6.

This study aimed to determine the effect of hamstring botulinum toxin A (Btx-A) injection in 10 children with crouch gait in terms of changes in muscle length and lower-limb kinematics. Before Btx-A injection limb kinematics were recorded. Maximum hamstring lengths and excursions were calculated by computer modelling of the lower limb. Data were compared with the averaged hamstring lengths of 10 control children. Hamstrings were defined as short if their length was shorter than the average maximum length minus one standard deviation. Gait analysis was repeated 2 weeks after isolated hamstring Btx-A injection. Pre- and postinjection kinematic data and muscle lengths were then compared. Four of 18 injected limbs in three subjects had short medial hamstring before injection, none of the subjects had short lateral hamstrings. Muscle excursion was significantly reduced in the short and adequate maximum muscle length groups. A significant increase in the semimembranosus and semitendinosus length in all of the injected limbs was noted. Only in the short muscle group was a significant increase in muscle excursion observed. Knee extension improved by 13 degrees in the adequate muscle length group and by 15.6 degrees in the short muscle length group. Pelvic tilt and hip flexion increased in both groups non-significantly. Average walking speed postinjection increased from 0.60 ms(-1) to 0.71 ms(-1). Short hamstrings are over-diagnosed in crouch gait. Hamstring Btx-A injection in patients with crouch gait produces significant, repeatable muscle lengthening and improved ambulatory function.

Introduction: Conventional methods for determining normative gait patterns consist of filtering marker trajectories prior to processing with subsequent averaging of individual normalized data. This may result in temporal shifts of key parameters and potentially distort normative datasets. Nevertheless, this is the standard method employed by state of the art motion analysis systems. This study compared two different methods of averaging filtered and unfiltered kinematic data. Methods: Forty-eight non-impaired children (22M, 26F, mean age 9.85 years, range 4.2‐17 years) underwent three-dimensional gait analysis using a Vicon system (Vicon, Oxford, UK). Gait data were processed with and without the Woltring filtering routine, commonly used to minimize markertrajectory noise.Filtered datawere importedintoMatlab(MathWorks,Natick,MA) wherea representativegait cycle (RGC) for each leg of all participants was selected. Mean and standard deviationvalues for left and right limbs (n = 96) forfiltered and unfiltered data were calculated for seven different parameters within the RGC, without respect to timing. Similar values were obtained using the standard method. The values from the different averaging methods with and without filtering were compared. Results: Differences of up to 2.28 were found between averaging methods and up to 3.318 between filtered and unfiltered data. Discussion: Both the Woltring filtering routine and the standard averaging method cause signal dampening. While a Matlab-based tool may afford greater scope when analysing kinematic gait data, the standard averaging method still returns representative values when utilising data from able-bodied subjects. # 2008 Elsevier B.V. All rights reserved.

The aim of the study was to establish if a relationship exists between the energy efficiency of gait, and measures of activity limitation, participation restriction, and health status in a representative sample of children with cerebral palsy (CP). Secondary aims were to investigate potential differences between clinical subtypes and gross motor classification, and to explore other relationships between the measures under investigation. A longitudinal study of a representative sample of 184 children with ambulant CP was conducted (112 males, 72 females; 94 had unilateral spastic C P, 84 had bilateral spastic C P, and six had non-spastic forms; age range 4-17 y; Gross Motor Function Classification System Level I, n=57; Level II, n=91; Level III, n=22; and Level IV, n=14); energy efficiency (oxygen cost) during gait, activity limitation, participation restriction, and health status were recorded. Energy efficiency during gait was shown to correlate significantly with activity limitations; no relationship between energy efficiency during gait was found with either participation restriction or health status. With the exception of psychosocial health, all other measures showed significant differences by clinical subtype and gross motor classification. The energy efficiency of walking is not reflective of participation restriction or health status. Thus, therapies leading to improved energy efficiency may not necessarily lead to improved participation or general health.

Thirty-nine ambulant children (22 with hemiplegia, 17 with diplegia) with spastic cerebral palsy receiving isolated gastrocnemius muscle injection with botulinum toxin A were studied prospectively. The children had a mean age of 6 years (range 3 to 13 years). Measurement of gastrocnemius muscle length was used to estimate the dynamic component of each child's spasticity and to quantify the response. There was a strong correlation between the dynamic component of spasticity before injection and the corresponding magnitude of the response after injection. Children undergoing repeated injections showed similar correlations. A strong correlation was found between the duration of response and the dynamic component. Children with hemiplegia showed twice the duration for a given dynamic component compared with those with diplegia when injected with the same total dose per unit body weight. Long-term lengthening did not occur for the cohort, although some patients showed a response at a 12-month follow-up. By delaying shortening, the injections may have a role in delaying the need for surgery. Injections were well tolerated with few side effects.

OBJECTIVE. The purpose of this analysis was to assess recruitment bias in a population-based study of locomotor ability in children with cerebral palsy.METHOD. A population-based case register was used as a sampling frame and was considered a highly ascertained record of children with the condition. A twin track approach to recruitment for the Locomotor Study was adopted through: (1) a specialist orthopedic service and (2) a community pediatric network on behalf of the case register. The subjects included children with cerebral palsy aged 4 to 16 years in 2003, able to walk ≥10 m, and a resident in Northern Ireland, as well as their parents.RESULTS. The Orthopaedic Service identified clinically distinct children with cerebral palsy in terms of type, severity, age, and geographic residence. More families responded to an invitation, and more were ultimately recruited into the study via the Orthopaedic Service compared with a case register using community pediatric contacts. Overall, 37.8% of the eligible cerebral palsy population participated in the Locomotor Study, but there was no evidence of any systematic biases in demographic or key clinical characteristics when compared with nonparticipants. One follow-up reminder led to an increase in recruitment of 10%.CONCLUSIONS. Care must be taken in the recruitment of children with cerebral palsy through clinic-based populations, although these routes may prove more successful in follow-up. Provided they are comprehensive, case registers have a valuable contribution to make to clinical research by providing a sampling frame including information on baseline characteristics of an affected population.

We have examined the effect of arthrodiastasis on the preservation of the femoral head in older children with Perthes’ disease. We carried out a prospective trial in boys over the age of eight years and girls over seven years at the time of the onset of symptoms. The patients had minimal epiphyseal collapse and were compared with a conventionally treated, consecutive, historical control group. Arthrodiastasis was applied for approximately four months. The primary outcome measure was the extent of epiphyseal collapse at the end of the fragmentation phase. One of the 15 treated hips and nine of the 30 control hips showed a loss of height of 50% or more of the lateral epiphyseal column on the anteroposterior radiographs (Herring grade-C classification). On a Lauenstein view, one of the treated hips and 19 of the control hips showed at least a loss of height of 50% of the anterior epiphyseal column. The complications of arthrodiastasis included pin-site infection in most hips, transient joint stiffness in two, and breakage of a pin in two. The final outcome will be known when all the patients and the control group reach skeletal maturity.

Out of 320 patients on the Northern Ireland Perthes' database, five were known to be twins. We observed that the low birthweight twin in each case was the affected child. It is proposed that environmental factors associated with low birthweight are involved in the aetiology of Perthes' disease.

The popliteal angle is a widely used clinical means of assessing hamstring length in cerebral palsy patients. The relevance of the popliteal angle as a measure of hamstring length was assessed in this prospective study. Sixteen patients with cerebral palsy with crouch gait had their conventional and modified popliteal angles measured by nine observers on two separate occasions. With use of the conventional and modified forms of the test, 74 and 70%, respectively, of the observed variability was inter-and intraobserver related. The range of SDs for each observer using the conventional test was 7.1-13.6 degrees (average 10.9 degrees ), and with use of the modified form of the test, the range was 6.3-4.2 degrees (average 10.5 degrees ). The maximum hamstring length of each subject during gait was determined by three-dimensional modelling of their lower limbs. The modified popliteal angle measurements of the most repeatable observer demonstrated an inverse relationship between modified popliteal angle and maximum hamstring length (p < 0.01) and muscle excursion (p < 0.01). Only 10 of 32 limbs had short medial hamstrings.

Recent studies have shown a marked variation in the standards of healthcare for young people with disabilities in different regions of the UK and even within the same health district. Equity in the provision of healthcare is a fundamental principle of the NHS. However, this can only be measured against an agreed minimal standard of healthcare that serves as a benchmark for healthcare purchasers and providers. The aim of the present document is to develop a set of minimum standards of healthcare for children and adults with cerebral palsy (CP).The document was developed in two stages by a multi-professional and multi-disciplinary group of practitioners in the field of CP. Initially, members of the panel jointly formulated a statement of what they believed should be the minimal acceptable standards of healthcare in CP drawing on their own experience and the published scientific evidence. In the second stage the views of some of the relevant professional bodies and voluntary organizations on the draft statement were sought. The responses of these organizations were incorporated into the final document if agreed by the panel.Twenty-two recommendations were made. These were considered the minimum standards of care in a district general hospital. The emphasis was on the organisation and delivery of healthcare for children with CP. The statement is intended to stimulate debate especially in relation to the equity of service provision throughout the country and may be used to inform purchasers of healthcare. Similarly, it may also be useful to providers of healthcare as an audit tool.

We examined the effect of ankle-foot orthoses (AFOs) on gait and energy expenditure in children with spina bifida. Nine boys and three girls, 6 to 16 years of age, took part in the study. There were four children each with L4, L5, and sacral level lesions. Each child underwent gait analysis and energy consumption studies with and without AFOs. Walking speed was faster with AFOs (mean, 58 m/min) than without (mean, 50 m/min, p < 0.01). Stride length improved significantly (p < 0.001) from 0.89 m barefoot to 1.08 m with AFOs. Double support time was decreased from 0.32 seconds barefoot to 0.28 seconds with AFOs (p < 0.05). The oxygen cost of walking was significantly better with (0.33 mL/kg/m) than without AFOs (0.41 mL/kg/m, p < 0.001). Hip flexion at initial contact was increased. Ankle kinematics were unchanged, but ankle power generation showed a significant improvement; from 0.5 W/kg barefoot to 1.3 W/kg with AFOs. Increased ankle power generation results in improved hip flexion and stride length, which contributes to increased walking speed and reduced oxygen cost. The stability conferred by the AFOs is reflected in the reduced time spent in double support.

It has been suggested that Perthes’ disease is more prevalent in urban areas, and that the risk increases with deprivation. We present the findings of a preliminary analysis of Perthes’ disease in Northern Ireland, which is shown to have one of the highest national annual rates of incidence in the world (11.6 per 100 000). Of the 313 children diagnosed over a seven-year period, 311 were allocated to the enumeration districts of the 1991 census, thus allowing the incidence to be calculated using both spatial and non-spatial aggregation. The cases were grouped according to the size of the settlement from highly urbanised to open countryside and by level of area deprivation. While the incidence of Perthes’ disease was found to be associated with indicators of the level of deprivation for areas, there was no evidence to suggest that there was an increased risk in urban areas; the highest rate was found in the most deprived rural category.

Conservative therapies for equinus in cerebral palsy may help to postpone calf surgery in younger children. This study reports a prospective randomised trial of intramuscular botulinum toxin A (BtA) as an alternative to serial casting in 20 children with a dynamic component to calf equinus. Outcome was assessed in the short term to show the effect of one treatment cycle. Assessments were by clinical examination, video gait analysis, and three-dimensional gait analysis. BtA was of efficacy similar to that of serial casting. Tone reduction in the BtA group allowed a more prolonged improvement in passive dorsiflexion, which may allow more opportunity for increase in muscle length. Gait analysis showed an improved mean ankle kinematic pattern in a subsection of both groups, which was maintained at 12 weeks in the BtA group, whereas the cast group relapsed. There were fewer side effects in the BtA group. Median time to reintervention was similar.

This paper describes a system to calculate gastrocnemius muscle length from three dimensional kinematic gait data and anthropometric measurements of children taken from MRI scans. As well as describing the simple model that may be applied to existing gait data, the anthropometric data for 15 able-bodied children is presented. The model is then used to describe gastrocnemius muscle lengths and the effect of different pathologies on muscle lengths by looking at cohorts of able-bodied children, children with a hemiplagic or diplegic pattern of cerebral palsy, a child undergoing tendo Achilles lengthening and a child with burns to his lower limbs. The results show the importance of using muscle lengths as part of a clinical assessment and the need to take the effects of skeletal growth into account when developing models for use in a paediatric population.

This study was designed to determine gait patterns in children with lumbar and sacral neurologic level spina bifida. We studied a group of 28 children: 10 had L4-level lesions and a mean age of 11 years; eight had L5-level lesions and a mean age of 8 years; and 10 had S1-level lesions with a mean age of 12 years. A group of 15 normal children, mean age 10 years, was used for comparison. Each child underwent three-dimensional gait analysis using the Vicon system. We found that there were recognisable gait patterns for each level of spina bifida and that the abnormalities accurately reflected the muscle deficiencies present. The gait patterns approximated more closely to those of the normal group as the neurological level descended. The most important findings were of increased pelvic obliquity and rotation with hip abduction in stance (reflecting the gross Trendelenburg-type gait seen in these children) and persistent knee flexion throughout stance as a result of the absence of the plantar flexion-knee extension couple. We found that gait was not improved by tendon transfers performed either at the hip (posterolateral psoas transfer) or at the ankle (tibialis anterior transfer).

Problem: The incidence of late diagnosed developmental dysplasia of the hip requiring surgery in Northern Ireland is high. The reported incidence was 1.14 per 1000 children born during 1983-7. Design: Comparative retrospective study. Background and setting: Clinical screening programme in Northern Ireland. Key measure for improvement: Reduced rate of operative intervention in children with developmental dysplasia of the hip detected after 6 months of age. Strategies for change: Increased emphasis on staff training, introduction of a centralised nurse led clinic to improve access to orthopaedic surgeons, and increased use of ultrasonography. Effects of change: The incidence of developmental dysplasia of the hip diagnosed after 6 months in children born between January 1991 and December 1997 fell to 0.59 per 1000, presumably due to improved early detection. Nevertheless, 29 (16%) of the affected hips were not diagnosed when the child was first referred in the first 3 months of life. In addition, for 27 affected hips in children diagnosed after the age of 6 months there was a known risk factor (family history or breech delivery). Lessons learnt: Improvements to screening processes can reduce late incidence of developmental dysplasia of the hip. Further steps to improve detection in children with known risk factors and rate of detection at first referral could reduce late presentation further.

Seven patients with osteoid osteoma of the proximal femur were treated by percutaneous excision of the nidus. The combination of preoperative localisation by tomography and intraoperative localisation by image intensifier resulted in a curative procedure with minimal bone resection in all cases, although a second operation was required in one patient.

While there is general clinical consensus that children with Unilateral Spastic Cerebral Palsy (USCP) walk with an increased anterior pelvic tilt and the affected hemipelvis retracted, there is less agreement to observations in the coronal plane. Furthermore, the relationship of 3D pelvic kinematic parameters to the Winters, Gage and Hicks (WGH) hemiplegic gait classification has not been reported in the literature. Valid 3-D kinematic gait data were obtained in a representative population of 91 children with hemiplegia (56 M, mean age 10.8 yrs, age range 5-18 yrs; WGH classification Type I n=32, II n=5, III n=7, IV n=9, unclassified n=38). Deviations of symmetry and range of movement from our normative data set (n=48; 26F; mean age 9.9 yrs; age range 5-18 yrs) for mean tilt, tilt range, and difference between affected and unaffected sides for obliquity and rotation were defined as normal, mild, moderate or severe (1 standard deviation (SD);12 SD;23 SD;3 SD, respectively). Increased pelvic tilt range (1 SD) was observed in 60.4% and pelvic retraction (1 SD) was observed in 61.5% of USCP children in this study. Weak but significant correlations were found between WGH gait type and pelvic obliquity (ρ=0.29; p0.01). No other correlations were found. Factors such as leg length discrepancy modify the functional leg length throughout the gait cycle contributing to the deviations observed. The evaluation of gait abnormalities in USCP should not be limited to the use of classifications based on sagittal plane kinematics but should seek to include 3D kinematics of the pelvis.

Recent reports have suggested an association between Perthes’ disease and an underlying thrombophilic or hypofibrinolytic tendency. In Northern Ireland there is a high incidence of Perthes’ disease (11.7 per 100 000 or 1 in 607 children) in a stable paediatric population. We reviewed 139 children with Perthes’ disease and compared them with a control group of 220 aged- and gender-matched healthy primary schoolchildren with similar racial and ethnic backgrounds. There were no significant deficiencies of antithrombotic factors protein C, protein S, antithrombin III or resistance to activated protein C. A total of 53 (38.1%) of the children with Perthes’ disease had a prolonged activated partial thromboplastin time (> 38) compared with 13 (5.9%) of the control group (p < 0.001). Our findings have shown that using standard assays, thrombophilia secondary to antithrombotic factor deficiency or resistance to activated protein does not appear to be an aetiological factor for Perthes’ disease. The cause of the prolonged activated partial thromboplastin time, usually associated with a clotting factor deficiency, is under further investigation.

In this paper, the relationship of the Gait Deviation Index (GDI) to gross motor function and its ability to distinguish between different Gross Motor Function Classification System (GMFCS) levels was determined. A representative sample of 184 ambulant children with CP in GMFCS levels I (n = 57), II (n = 91), III (n = 22) and IV (n = 14) were recruited as part of a population-based study. Representative gait cycles were selected following a 3D gait analysis and gross motor function was assessed using the Gross Motor Function Measure (GMFM). GDI scores were calculated in Matlab. Valid 3D kinematic data were obtained for 173 participants and both kinematic and GMFM data were obtained for 150 participants. A substantial relationship between mean GDI and GMFM-66 scores was demonstrated (r = 0.70; p < 0.001) with significant differences in mean GDI scores between GMFCS levels (p < 0.001) indicating increasing levels of gait deviation in subjects less functionally able. The relationship between the GDI, GMFM and GMFCS in a representative sample of ambulators, lends further weight to the validity of the GDI scoring system. Furthermore it suggests that the subtleties of gait may not be wholly accounted for by gross motor function evaluation alone. Gait specific tools such as the GDI more likely capture both the functional and aesthetic components of walking.

This study describes sagittal plane gait patterns in a representative sample of children with hemiplegic cerebral palsy (CP). Ninety-four children were prospectively recruited to the study (age range 5–18 yrs, mean age 10 yrs 7 mo) and valid kinematic data was captured for 91 participants. Data was also captured for 49 children (age range 5–18 yrs, mean age 10 yrs) with no physical impairment. One representative gait cycle from each child was exported to an Excel template and run through an algorithm that facilitated the description of gait, using logical arguments derived from Winters’ Classification. Children with hemiplegic CP, regardless of past surgery history, were allocated to the following gait types: Groups IV (n = 9; 10%), III (n = 7: 8%), II (n = 5: 5%), I (n = 32: 35%) and not classified (n = 38: 42%). For children with no lower limb surgical history (n = 61), gait types were: Groups IV (n = 7: 12%), III (n = 2: 3%), II (n = 2: 3%), I (n = 20: 33%) and not classified (n = 30: 49%). The gait data taken from children with no physical impairment were not classified. The ability of the Winters’ classification system to distinguish between children with higher levels of hemiplegic involvement and children with no physical impairment was demonstrated: the majority of children with hemiplegic CP present with relatively minor gait deviations. A more complete definition of sagittal plane ankle joint kinematics may account for those children that were not classified.

Difficulties with direct measurement of oxygen (O2) consumption have led to the use of simpler proxy measures to estimate energy efficiency in children with cerebral palsy. This study aimed to investigate the relationship between a fast 1-minute walk test and O2 cost in children with bilateral spastic cerebral palsy. Eighty-four children (31 girls, 53 boys; mean age, 10 years 11 months; Gross Motor Function Classification System level I n = 8, level II n = 41, level III n = 21, level IV n = 14) were eligible to participate in the study. Seventy-seven children completed the walk test and 47 children completed the O2 consumption protocol. Results showed significant differences between Gross Motor Function Classification System levels for both tests (P < 0.001) and a significant moderate quadratic relationship between the distance covered during the 1-minute fast-walk test and the net O2 cost (adjusted r = 0.477; P < 0.001). The 1-minute fast-walk test may provide useful information on the efficiency of gait in children with bilateral spastic cerebral palsy in the absence of more sophisticated equipment; however, further work is required to address its reliability and responsiveness.

A randomized placebo-controlled trial was carried out to investigate the efficacy of neuromuscular electrical stimulation (NMES) and threshold electrical stimulation (TES) in strengthening the quadriceps muscles of both legs in children with cerebral palsy (CP). Sixty children (38 males, 22 females; mean age 11y [SD 3y 6mo]; age range 5-16y) were randomized to one of the following groups: NMES (n=18), TES (n=20), or placebo (n=22). Clinical presentations were diplegia (n=55), quadriplegia (n=1), dystonia (n=1), ataxia (n=1), and non-classifiable CP (n=2). Thirty-four children walked unaided, 17 used posterior walkers, six used crutches, and the remaining three used sticks for mobility. Peak torque of the left and right quadriceps muscles, gross motor function, and impact of disability were assessed at baseline and end of treatment (16wks), and at a 6-week follow-up visit. No statistically significant difference was demonstrated between NMES or TES versus placebo for strength or function. Statistically significant differences were observed between NMES and TES versus placebo for impact of disability at the end of treatment, but only between TES and placebo at the 6-week follow-up. In conclusion, further evidence is required to show whether NMES and/or TES may be useful as an adjunct to therapy in ambulatory children with diplegia who find resistive strengthening programmes difficult.

The concurrent validity of a 1 minute walk test at a child's maximum walking speed was assessed in children with bilateral spastic cerebral palsy (BSCP). The distance covered during the 1 minute walk test was compared with the children's gross motor function as assessed by the Gross Motor Function Measure (GMFM). Twenty-four male and 10 female children with CP (mean age 11y, range 4 to 16y) participated in the study. Gross Motor Function Classification System (GMFCS) levels were; level I (n=3), level II (n=17), level III (n=10), and level IV (n=4). Participants had clinical diagnoses of symmetrical diplegia (n=19), asymmetrical diplegia (n=14), and quadriplegia (n=1). Results showed a significant correlation between GMFM score and the distance covered during the 1 minute walk (r=0.92; p

Children with Perthes disease have been thought to be of smaller stature than their peers. No reproducible evidence exists to demonstrate an endocrinopathy as the cause. This study reviewed 139 children with Perthes disease. Height and weight were recorded and compared with standardized growth charts. A blood sample was analyzed for thyroid stimulating hormone (TSH), thyroxin (T4), and insulin-like growth factor 1 (IGF1). Two urine samples were collected at 8 am and 8 pm within 24 hours. From these a cortisol/creatinine ratio was calculated. The results were compared with those from 40 healthy matched controls. No significant differences were found between the study or control children for levels of TSH, T4, IGF1, or cortisol. Review of the height and weight results revealed that the study children were of normal body habitus compared with the general pediatric population and do not undergo a period of growth acceleration following the active stages of the disease.

The Herring lateral pillar classification has been shown to be a useful predictor of subsequent femoral head deformity in Perthes disease. The initial Herring classification, however, can often be misleading with regard to outcome, as further collapse can occur. The purpose of this study was to assess the predictability of the initial Herring classification. The radiographs of 253 patients (275 hips) conservatively treated were reviewed. The Herring grade was recorded on both the first and subsequent radiograph, and any change in grade was noted. Ninety-two hips required upgrading. The average duration of symptoms to the initial radiograph was 108 days compared with 204 days in the group showing no change. The predictability of the initial Herring classification is related to time from onset of symptoms. The greater the duration of symptoms, the more accurate the initial grading; 7 months is the average time at which one could expect no further collapse.

An attempt was made to validate a system of calculating mechanical cost using 3-D motion analysis by using Oxygen cost measurements in 26 subjects with myelomeningocele. The three models investigated were (i) vertical excursion of the centre of mass (model 1), (ii) external work done by the centre of mass (CM) (model 2) and (iii) a full body model allowing energy transfers between segments within limbs (model 3). Oxygen cost, and models 1 and 3 all demonstrated significant differences between S1 and L4/L5 level involvement (P=0.001, 0.002 and 0.01, respectively). No significant differences were observed between subjects who had L4 and L5 level involvement. While further analysis showed a moderate correlation between Oxygen cost and the vertical excursion of CM model (R2=0.60), a lack of correlation for the more sophisticated models 2 and 3 questions their use as a method of assessing the energy cost of locomotion in this population.

The authors looked for differences in the energy expenditure patterns of ambulant children with cerebral palsy and spina bifida. Oxygen consumption was measured according to type of cerebral palsy or level of spina bifida lesion, and in healthy children. The rate of oxygen consumption (mL/kg/min) was significantly higher in the children with diplegia than in those with hemiplegia or with spina bifida or the healthy children. Oxygen cost (mL/kg/m) was significantly higher and velocity was significantly slower in all the groups with disability than in the healthy children. The reason children with diplegia consumed more oxygen than other children when walking may be that their abnormal equilibrium reactions impaired their balance and their ability to control their walking speed.

Eighteen children with hemiplegia, mean age 8 years 5 months, underwent gait analysis and musculoskeletal modelling using specially designed software. The maximum lengths of the hamstrings were determined for each child walking in and out of an ankle-foot orthosis (AFO). The muscles were deemed to be short if shorter than the normal average -1SD. In bare feet 8 participants had short medial hamstrings with a higher proportion of these in the less involved individuals. All participants showed an increase in maximum hamstring length when wearing an AFO. In all but one child this was sufficient to restore hamstring length to within normal limits. These finding suggest that hamstring pathology in hemiplegic gait is usually secondary to more distal lower limb pathology.

This study aimed to determine the effect of hamstring botulinum toxin A (Btx-A) injection in 10 children with crouch gait in terms of changes in muscle length and lower-limb kinematics. Before Btx-A injection limb kinematics were recorded. Maximum hamstring lengths and excursions were calculated by computer modelling of the lower limb. Data were compared with the averaged hamstring lengths of 10 control children. Hamstrings were denned as short if their length was shorter than the average maximum length minus one standard deviation. Gait analysis was repeated 2 weeks after isolated hamstring Btx-A injection. Pre- and postinjection kinematic data and muscle lengths were then compared. Four of 18 injected limbs in three subjects had short medial hamstring before injection, none of the subjects had short lateral hamstrings. Muscle excursion was significantly reduced in the short and adequate maximum muscle length groups. A significant increase in the semimembranosus and semitendinosus length in all of the injected limbs was noted. Only in the short muscle group was a significant increase in muscle excursion observed. Knee extension improved by 13° in the adequate muscle length group and by 15.6° in the short muscle length group. Pelvic tilt and hip flexion increased in both groups non-significantly. Average walking speed postinjection increased from 0.60 ms-1 to 0.71 ms-1. Short hamstrings are over-diagnosed in crouch gait. Hamstring Btx-A injection in patients with crouch gait produces significant, repeatable muscle lengthening and improved ambulatory function.

The use of botulinurn toxin in cerebral palsy is an attractive proposition on two counts. Reduction of the over-activity of the spastic muscles may, in the short term, improve function. Reduction of the over-activity may also permit increased longitudinal growth and decrease the severity of contractures. Using the hereditary spastic mouse as an animal model for the development of contractures we have shown that treatment of the growing muscle with botulinurn toxin A can restore normal longitudinal muscle growth. Over the last six years we have treated I53 children with cerebral palsy with intramuscular botulinurn toxin A. These subjects have been treated in five specific clinical trials and have continued in an open label ongoing clinical study. These studies have shown promising results with no significant side-effects or safety concerns. There were improvements in patient and physician rating of function. Ninety four percent of patients demonstrated clinically significant reduction in tone of the injected muscles following injection. The studies incorporating gait analysis showed improvements in the measured parameters following both calf muscle and hamstring injection with botulinum toxin. These improvements have been more marked in younger patients. In a study comparing the effects of calf injection versus serial casting in hemiplegic subjects botulinurn toxin had a longer duration of action than casting and was better tolerated by subjects. A further study of isolated injection of the hamstrings showed an improvement of gait parameters in most subjects. However, a significant subset showed a modest deterioration in gait parameters, particularly with increased anterior pelvic tilt; this effect wore off with the toxin. This has allowed us to identify patients were the role of the hamstrings in extending the hip is more critical than any excessive knee flexion and in whom hamstring surgery should be avoided. Another study addressed the upper limb in hemiplegia. In this study the spasticity was measured by measuring the resonant frequency of the forearm flexors. This study, which was double-blind. demonstrated clearly that the resonant frequency of the spastic muscle could be reduced by botulinurn toxin, and that this effect lasted up to six months. Objective functional measures showed no significant changes. however. most patients were objectively pleased with the outcome of injection. More recent studies measuring the functional lengths of the calf muscles during gait before and after botulinurn toxin have shown interesting insights into the action of botulinurn toxin. Most patients have shown good improvements in phasic eccentric relaxation of muscle with little compromise of concentric contraction at push-off. This suggests that the toxin may have a greater action on the intrafusal muscle tibres of the stretch receptors than the extrafusal motor fibres. In conclusion we have found botulinum toxin to b-e a useful adjuvant treatment in the management of younger patients with cerebral palsy. It