Botulinum neurotoxin type A responders among children with spastic cerebral palsy: Pattern-specific effects

AIM

To identify short-term effects of botulinum neurotoxin type A (BoNT) injections on gait and clinical impairments, in children with spastic cerebral palsy (CP), based on baseline gait pattern-specific subgroups.

METHOD

Short-term effects of BoNT injections in the medial hamstrings and gastrocnemius were defined in a retrospective convenience sample of 117 children with CP (median age: 6 years 4 months; GMFCS I/II/III: 70/31/16; unilateral/bilateral: 56/61) who had received gait analyses before and 2 months post-BoNT. First, baseline gait patterns were classified. Statistical and meaningful changes were calculated between pre- and post-BoNT lower limb sagittal plane kinematic waveforms, the gait profile score, and non-dimensional spatiotemporal parameters for the entire sample and for pattern-specific subgroups. These gait waveforms per CP subgroup at pre- and post-BoNT were also compared to typically developing gait and composite scores for spasticity, weakness, and selectivity were compared between the two conditions.

RESULTS

Kinematic improvements post-BoNT were identified at the ankle and knee for the entire sample, and for subgroups with apparent equinus and jump gait. Limbs with baseline patterns of dropfoot and to a lesser extent true equinus showed clear improvements only at the ankle. In apparent equinus, jump gait, and dropfoot, spasticity improved post-BoNT, without leading to increased weakness or diminished selectivity. Compared to typical gait, knee and hip motion improved in the crouch gait subgroup post-BoNT.

CONCLUSION

This comprehensive analysis highlighted the importance of investigating BoNT effects on gait and clinical impairments according to baseline gait patterns. These findings may help identify good treatment responders.

Identification of the neural component of torque during manually-applied spasticity assessments in children with cerebral palsy

Clinical assessment of spasticity is compromised by the difficulty to distinguish neural from non-neural components of increased joint torque. Quantifying the contributions of each of these components is crucial to optimize the selection of anti-spasticity treatments such as botulinum toxin (BTX). The aim of this study was to compare different biomechanical parameters that quantify the neural contribution to ankle joint torque measured during manually-applied passive stretches to the gastrocsoleus in children with spastic cerebral palsy (CP). The gastrocsoleus of 53 children with CP (10.9 ± 3.7 y; females n = 14; bilateral/unilateral involvement n = 28/25; Gross Motor Functional Classification Score I-IV) and 10 age-matched typically developing (TD) children were assessed using a manually-applied, instrumented spasticity assessment. Joint angle characteristics, root mean square electromyography and joint torque were simultaneously recorded during passive stretches at increasing velocities. From the CP cohort, 10 muscles were re-assessed for between-session reliability and 19 muscles were re-assessed 6 weeks post-BTX. A parameter related to mechanical work, containing both neural and non-neural components, was compared to newly developed parameters that were based on the modeling of passive stiffness and viscosity. The difference between modeled and measured response provided a quantification of the neural component. Both types of parameters were reliable (ICC > 0.95) and distinguished TD from spastic muscles (p < 0.001). However, only the newly developed parameters significantly decreased post-BTX (p = 0.012). Identifying the neural and non-neural contributions to increased joint torque allows for the development of individually tailored tone management.

Instrumented assessment of the effect of Botulinum Toxin-A in the medial hamstrings in children with cerebral palsy

This study examined the sensitivity of an instrumented spasticity assessment of the medial hamstrings (MEH) in children with cerebral palsy (CP). Nineteen children received Botulinum Toxin type A (BTX-A) injections in the MEH. Biomechanical (position and torque) and electrophysiological (surface electromyography, EMG) signals were integrated during manually-performed passive stretches of the MEH at low, medium and high velocity. Signals were examined at each velocity and between stretch velocities, and compared pre and post BTX-A (43 ± 16 days). Average change between pre and post BTX-A was interpreted in view of the minimal detectable change (MDC) calculated from previously published reliability results. Improvements greater than the MDC were found for nearly all EMG-parameters and for torque parameters at high velocity and at high versus low velocity (p<0.03), however large inter-subject variability was noted. Moderate correlations were found between the improvement in EMG and in torque (r=0.52, p<0.05). Biomechanical and electrophysiological parameters proved to be adequately sensitive to assess the response to treatment with BTX-A. Furthermore, studying both parameters at different velocities improves our understanding of spasticity and of the physiological effect of selective tone-reduction. This not only provides a clinical validation of the instrumented assessment, but also opens new avenues for further spasticity research.

A clinical measurement to quantify spasticity in children with cerebral palsy by integration of multidimensional signals

Most clinical tools for measuring spasticity, such as the Modified Ashworth Scale (MAS) and the Modified Tardieu Scale (MTS), are not sufficiently accurate or reliable. This study investigated the clinimetric properties of an instrumented spasticity assessment. Twenty-eight children with spastic cerebral palsy (CP) and 10 typically developing (TD) children were included. Six of the children with CP were retested to evaluate reliability. To quantify spasticity in the gastrocnemius (GAS) and medial hamstrings (MEH), three synchronized signals were collected and integrated: surface electromyography (sEMG); joint-angle characteristics; and torque. Muscles were manually stretched at low velocity (LV) and high velocity (HV). Spasticity parameters were extracted from the change in sEMG and in torque between LV and HV. Reliability was determined with intraclass-correlation coefficients and the standard error of measurement; validity by assessing group differences and correlating spasticity parameters with the MAS and MTS. Reliability was moderately high for both muscles. Spasticity parameters in both muscles were higher in children with CP than in TD children, showed moderate correlation with the MAS for both muscles and good correlation to the MTS for the MEH. Spasticity assessment based on multidimensional signals therefore provides reliable and clinically relevant measures of spasticity. Moreover, the moderate correlations of the MAS and MTS with the objective parameters further stress the added value of the instrumented measurements to detect and investigate spasticity, especially for the GAS.

Reliability of head and trunk kinematics during gait in children with spastic diplegia

This study describes the reliability of a clinically oriented model for three-dimensional movement analysis of head and trunk movements in children with spastic diplegia. The model consists of five rigid segments (head, thorax, pelvis, shoulder line, spine) and includes a detailed analysis of spinal segmental movements. Within and between session reliability during gait was tested in 10 children with spastic diplegia (6-14yrs). Reliability of discrete parameters was assessed with the intraclass correlation coefficient (ICC) and similarity of thorax and pelvis waveforms with the coefficient of multiple correlation (CMC). Measurement errors were calculated for all parameters (SEM, σ). Results indicated acceptable within and between session reliability of discrete parameters for thorax, pelvis, shoulder line, angle of kyphosis and the majority of the spinal segmental angles, reflected by low SEMs (<4°) and most ICCs>0.60. Within and between session waveform errors were below 4°. CMCs ranged from poor to very good, with highest values for movements in the frontal and transversal planes. The angle of lordosis showed lower between session reliability for several discrete parameters, although waveform errors were still below 5°. Head parameters showed lower overall reliability. The results of this study support the reliability of the proposed model. Head kinematic parameters should be interpreted with caution, due to difficulties in standardization. Accurate palpation of the spinal markers, especially the lumbar spine, is critical and demands thorough training of the assessor.

Increased mechanical cost of walking in children with diplegia: the role of the passenger unit cannot be neglected

Gait efficiency in children with cerebral palsy is decreased. To date, most research did not include the upper body as a separate functional unit when exploring these changes in gait efficiency. Since children with spastic diplegia often experience problems with trunk control, they could benefit from separate evaluation of the so-called 'passenger unit'. Therefore, the aim of the current study was to improve insights in the role of the passenger unit in decreased gait efficiency in children with diplegia. Mechanical cost of walking was investigated by calculating work by the integrated joint power approach in 18 children with diplegia and 25 age-related typical developing controls. The total mechanical work in children with diplegia was 1.5 times higher than in typical children. In children with diplegia work at the lower limbs was increased by 37% compared to typical children. Substantially higher increases, up to 222%, were noted at the passenger unit. Trunk and head were the main contributors to the increased work of the passenger unit, but the role of the arms cannot be neglected. Due to these disproportional increases in locomotor and passenger unit, the demands of the passenger unit in pathological gait can no longer be considered minor, as in typical gait. Therefore, the role of the passenger unit must be recognized in the decrease of gait efficiency in children with spastic diplegia and should be part of the evaluation of gait efficiency in clinical practice.

To what extent is mean EMG frequency during gait a reflection of functional muscle strength in children with cerebral palsy?

The aim of the current paper was to analyze the potential of the mean EMG frequency, recorded during 3D gait analysis (3DGA), for the evaluation of functional muscle strength in children with cerebral palsy (CP). As walking velocity is known to also influence EMG frequency, it was investigated to which extent the mean EMG frequency is a reflection of underlying muscle strength and/or the applied walking velocity. Surface EMG data of the lateral gastrocnemius (LGAS) and medial hamstrings (MEH) were collected during 3DGA. For each muscle, 20 CP children characterized by a weak and 20 characterized by a strong muscle (LGAS or MEH) were selected. A weak muscle was defined as a manual muscle testing score <3; a strong muscle was defined as a manual muscle testing score ≥4. Patient selection was based on the following inclusion criteria: (a) predominantly spastic type of CP (3-15 years old), (b) either (near) normal muscle strength or muscle weakness in at least one of the studied lower limb muscles, (c) no lower limb Botulinum Toxin-A treatment within 6 months prior to the 3DGA, (d) no history of lower limb surgery, and (e) high-quality noise-free EMG-data. For each muscle, twenty age-related typically developing (TD) children were included as controls. In both muscles a consistent pattern of increasing mean EMG frequency with decreasing muscle strength was observed. This was significant in the LGAS (TD versus weak CP). Walking velocity also had a significant effect on mean EMG frequency in the LGAS. Furthermore, based on R(2) and partial correlations, it could be concluded that both walking velocity and muscle strength have an impact on EMG, but the contribution of muscle strength was always higher. These findings underscore the potential of the mean EMG frequency recorded during 3DGA, for the evaluation of functional muscle strength in children with CP.

The effect of different physiotherapy interventions in post-BTX-A treatment of children with cerebral palsy

AIM

To distinguish the effects of different physiotherapeutic programs in a post BTX-A regime for children with Cerebral Palsy (CP).

DESIGN

Retrospective, controlled intervention study.

PARTICIPANTS AND INTERVENTIONS

A group of 38 children (X¯ = 7y7m, GMFCS I-III, 27 bilateral, 11 unilateral CP) receiving an individually defined Neurodevelopment Treatment (NDT) program, was matched and compared to a group of children with the same age, GMFCS and diagnosis, receiving more conventional physiotherapy treatment. All patients received selective tone-reduction by means of multilevel BTX-A injections and adequate follow-up treatment, including physiotherapy.

OUTCOME MEASURES

Three-dimensional gait analyses and clinical examination was performed pre and two months post-injection. Treatment success was defined using the Goal Attainment Scale (GAS).

RESULTS

Both groups' mean converted GAS scores were above 50. The average converted GAS score was higher in the group of children receiving NDT than in the group receiving conventional physiotherapy (p < 0.05). In the NDT group, overall treatment success was achieved in 76% of the goals, compared to 67% of the goals defined for the conventional physiotherapy group. Especially for the goals based on gait analyses (p < 0.05) and in the group of children with bilateral CP (p < 0.05), treatment success was higher in the NDT group.

CONCLUSION

In a post-BTX-A regime, the short-term effects of an NDT approach are more pronouncedthan these from a conventional physiotherapy approach.

Botulinum toxin assessment, intervention and after-care for lower limb spasticity in children with cerebral palsy: international consensus statement

Botulinum neurotoxin type-A (BoNT-A) has been used in association with other interventions in the management of spasticity in children with cerebral palsy (CP) for almost two decades. This consensus statement is based on an extensive review of the literature by an invited international committee. The use of BoNT-A in the lower limbs of children with spasticity caused by CP is reported using the American Academy of Neurology Classification of Evidence for therapeutic intervention. Randomized clinical trials have been grouped into five areas of management, and the outcomes are presented as treatment recommendations. The assessment of children with CP and evaluation of outcomes following injection of BoNT-A are complex, and therefore, a range of measures and the involvement of a multidisciplinary team is recommended. The committee concludes that injection of BoNT-A in children with CP is generally safe although systemic adverse events may occur, especially in children with more physical limitations (GMFCS V). The recommended dose levels are intermediate between previous consensus statements. The committee further concludes that injection of BoNT-A is effective in the management of lower limb spasticity in children with CP, and when combined with physiotherapy and the use of orthoses, these interventions may improve gait and goal attainment.

Upper limb motor and sensory impairments in children with hemiplegic cerebral palsy. Can they be measured reliably?

PURPOSE

To establish interrater and test-retest reliability of a clinical assessment of motor and sensory upper limb impairments in children with hemiplegic cerebral palsy aged 5-15 years.

METHOD

The assessments included passive range of motion (PROM), Modified Ashworth Scale (MAS), manual muscle testing (MMT), grip strength, the House thumb and Zancolli classification and sensory function. Interrater reliability was investigated in 30 children, test-retest reliability in 23 children.

RESULTS

For PROM, interrater reliability varied from moderate to moderately high (correlation coefficients 0.48-0.73) and test-retest reliability was very high (>0.81). For the MAS and MMT, total score and subscores for shoulder, elbow, and wrist showed a moderately high to very high interrater reliability (0.60-0.91) and coefficients of >0.78 for test-retest reliability. The reliability for the individual muscles varied from moderate to high. The Jamar dynamometer was found to be highly reliable. The House thumb classification showed a substantial reliability and the Zancolli classification an almost perfect reliability. All sensory modalities had a good agreement.

CONCLUSIONS

For all motor and sensory assessments, interrater and test-retest reliability was moderate to very high. Test-retest reliability was clearly higher than interrater reliability. To improve interrater reliability, it was recommended to strictly standardize the test procedure, refine the scoring criteria and provide intensive rater trainings.

The effect of individually defined physiotherapy in children with cerebral palsy (CP)

AIM

This prospective double blind intervention study aims to evaluate the effectiveness of an individually defined physiotherapy program on the function and gait pattern of 16 children with diplegia (age 3-12 year, GMFCS I-II).

METHOD

A 6 weeks general training program was followed by a specific training program based on individual goals determined by the results of 3D gait analyses, GMFM-88 and a clinical evaluation. Goal attainment scores were used for the evaluation of the achievement of individual goals.

RESULTS

After the general training program, 6.7% of the children achieved the treatment goals, 33.3% stayed at the same level and 60% worsened and this in comparison to 40, 33.3 and 26.6% of the children respectively after the individually defined training program. The improvement for walking, running and jumping of the GMFM-88 was significantly more pronounced after the individually defined (p < 0.05), compared to the general training program. Whereas ankle dorsiflexion, spasticity of the hamstrings (p < 0.01), selectivity of hip abductors, knee extensors and ankle dorsiflexors significantly improved over the complete period of study (p < 0.01), hip extension, step length, stride length, ankle power generation and all hip parameters changed specifically after the individually defined training program (p < 0.01).

CONCLUSION

A quantified effect is manifest with the application of an individually defined training program over a six weeks period.

A systematic review of arm activity measures for children with hemiplegic cerebral palsy

OBJECTIVE

To identify psychometrically sound and clinically feasible assessments of arm activities in children with hemiplegic cerebral palsy for implementation in research and clinical practice.

DATA SOURCES

PubMed, CINAHL, Cochrane Library, Web of Science and reference lists of relevant articles were searched.

REVIEW METHODS

A systematic search was performed based on the following inclusion criteria: (1) evaluative tools at the activity level according to the International Classification of Functioning, Disability and Health; (2) previously used in studies including children with hemiplegic cerebral palsy aged 2-18 years; (3) at least one aspect of reliability and validity in children with cerebral palsy should be established. Descriptive information, psychometric properties and clinical utility were reviewed.

RESULTS

Eighteen assessments were identified of which 11 met the inclusion criteria: eight functional tests and three questionnaires. Five functional tests were condition-specific, three were generic. All functional tests measure different aspects of activity, including unimanual capacity and performance during bimanual tasks. The questionnaires obtain information about the child's abilities at home or school. The reliability and validity have been established, though further use in clinical trials is necessary to determine the responsiveness.

CONCLUSIONS

To obtain a complete view of what the child can do and what the child actually does, we advise a capacity-based test (Melbourne Assessment of Unilateral Upper Limb Function), a performance-based test (Assisting Hand Assessment) and a questionnaire (Abilhand-Kids). This will allow outcome differentiation and treatment guidance for the arm in children with cerebral palsy.

Comparison of the Melbourne Assessment of Unilateral Upper Limb Function and the Quality of Upper Extremity Skills Test in hemiplegic CP

This study investigated interrater reliability and measurement error of the Melbourne Assessment of Unilateral Upper Limb Function (Melbourne Assessment) and the Quality of Upper Extremity Skills Test (QUEST), and assessed the relationship between both scales in 21 children (15 females, six males; mean age 6y 4mo [SD 1y 3mo], range 5-8y) with hemiplegic CP. Two raters scored the videotapes of the assessments independently in a randomized order. According to the House Classification, three participants were classified as level 1, one participant as level 3, eight as level 4, three as level 5, one participant as level 6, and five as level 7. The Melbourne Assessment and the QUEST showed high interrater reliability (intraclass correlation 0.97 for Melbourne Assessment; 0.96 for QUEST total score; 0.96 for QUEST hemiplegic side). The standard error of measurement and the smallest detectable difference was 3.2% and 8.9% for the Melbourne Assessment and 5.0% and 13.8% for the QUEST score on the hemiplegic side. Correlation analysis indicated that different dimensions of upper limb function are addressed in both scales.

Safety and efficacy of botulinum toxin type A following long-term use

Botulinum toxin serotype A (BoNT-A) has long heritage of use leading to confidence in its safety and efficacy. The application of BoNT-A does not lead to persistent histological changes in the nerve terminal or the target muscle. Clinical trials defined the safety and tolerability profile of BoNT-A across common therapeutic indications and showed an incidence of adverse events of approximately 25% in the BoNT-A-treated group compared with 15% in the control group. Focal weakness was the only adverse event to occur more often following BoNT-A treatment. Long-term BoNT-A administration has been assessed in various treatment settings, with the level and duration of BoNT-A efficacy response being maintained over repeated rounds of injection with no major safety concerns. The treatment of children with cerebral palsy often require long-term, repeated, multimuscle BoNT-A injections that lead to the administration of comparably higher toxin doses. Despite the high total body doses used, their distribution over multiple muscles and injection sites means that systemic side effects are rare. Recent formulation changes have reduced the incidence of antibody development following treatment with BOTOX. These findings show long-term BoNT-A treatment to be both safe and efficacious for a wide variety of indications.

Clinical value of botulinum toxin in neurological indications

Botulinum toxin type-A (BoNT-A) prevents the release of acetylcholine at cholinergic junctions, thereby causing temporary muscle weakness lasting 3-4 months. It is now widely used to treat a broad range of clinical disorders characterized by muscle hyperactivity. BoNT-A has proved effective in the management of several neurological conditions and, in particular, in the management of movement disorders (e.g. blepharospasm, cervical dystonia, laryngeal dystonia, limb dystonia, hemifacial spasm, focal tics, tremor and other hyperkinetic disorders). As a treatment of spasticity, BoNT-A can improve mobility and dexterity as well as preventing the development of distressing and costly secondary complications. In cerebral palsy, BoNT-A is of value, being able to delay or even avoid surgery until motion patterns have become established.

Botulinum toxin type A in the treatment of children and adolescents with an acquired brain injury

PRIMARY OBJECTIVE

To describe clinical experience using botulinum toxin type A (BTX-A) in children with acquired brain injury.

RESEARCH DESIGN

Single centre, open label, pilot study.

METHODS AND PROCEDURES

Twenty-one patients were randomized to three groups according to impairment severity and treatment objectives.

EXPERIMENTAL INTERVENTIONS

Group 1: Spastic quadriparesis patients with impaired consciousness treated with the primary goal of improving comfort and well-being; Group 2: Patients with upper limb spasticity treated with the primary goal of improving arm functioning; Group 3: Lower limb spasticity patients treated with the primary goal of improving leg function.

OUTCOMES AND RESULTS

Baseline, 1, 3 and 5-month post-treatment assessments were carried out using joint goniometry, Modified Ashworth Scale and video-observations. All groups demonstrated initial improvements, with patients in Group 2 showing a positive effect at least 5 months post-treatment.

CONCLUSIONS

With a good outlining of treatment goals, BTX-A is an effective therapy for brain injury patients.

Botulinumtoxin A bei der Behandlung der infantilen Zerebralparese

Botulinum toxin A represents a significant development in the management of children and adolescents with spastic cerebral palsy. Prerequisites for an adequate result are a correct indication, an exact injection technique and an intensive post-treatment programme. Spastic muscle overactivity and the constant tendency of the involved muscles to shorten with growth cannot be treated by only one method. Therefore a multilevel approach and an integrated treatment schedule including plaster of Paris, orthoses and physiotherapy are currently the best ways to modify the disease process. The inclusion of objective clinical documentation techniques combined with 3-D instrumented gait analysis allows the determination of the indications more exactly and for monitoring the post-treatment results. If started early and correctly, this integrated management approach has the potential to modify the natural history of the disorder, and to reduce the frequency of later surgery.

Kinematic and kinetic evaluation of the ankle after intramuscular injection of botulinum toxin A in children with cerebral palsy

Intramuscular botulinum toxin A (BTA) injection has a role in the conservative management of dynamic equinus deformity in children with cerebral palsy. The effect of BTA injection of the gastrocsoleus muscle during gait was evaluated. Eight children with hemiplegia (median age 4.4 years, range 2 to 8 years) were included in this retrospective study. Assessment included kinematic and kinetic gait analysis before and after (median 57.5 days) treatment. Postinjective kinematics showed significant improvement of ankle range of motion in the stance phase of gait. Ankle kinetics demonstrated a significant decrease of pathological power generation in midstance. The ankle power quotient (APQ) was also significantly improved. Ankle power in terminal stance was improved, although not to a significant level. These results provide evidence of normalization of energy production at the ankle, which is critical for normal gait. The effect of BTA is temporary and can be successfully repeated. This allows deferring the need for surgical intervention until the child is older and recurrence rate is lower.

A randomized study of combined botulinum toxin type A and casting in the ambulant child with cerebral palsy using objective outcome measures

It is recognized that objective gait analysis is of great value in planning a multilevel botulinum toxin type A (BTX-A) treatment. After BTX-A treatment, objective outcome measures can provide new and interesting information for each individual child with cerebral palsy (CP). Moreover, by studying group results, we may evaluate our treatment hypotheses. The present prospective study attempts to document the effect of integrated multilevel BTX-A treatment on objective gait parameters and to define the optimal strategy for the combined treatment of BTX-A with casting in children with cerebral palsy. Objective three-dimensional gait analysis (3DGA) data were collected pre- and 2 months post-treatment, in two randomized patient groups: a first group of 17 children treated with lower leg casting prior to BTX-A injections, and a second group of 17 patients who received casting immediately after injections. The present study demonstrates that improved gait can be achieved after a multilevel BTX-A treatment, combined with casting, using a set of 90 gait parameters. The most pronounced improvement was seen at the ankle joint. The results in the knee, hip and pelvis imply that multilevel treatment of the child with CP should start at an early age, in order to prevent development of muscle contractures. Slightly more pronounced benefits, mainly in the proximal joints, were seen for the children who were casted after injections as compared to the children who were casted before injections.

Single event multilevel botulinum toxin type A treatment and surgery: similarities and differences

The present study attempts to provide objective evidence of two treatment options for children with cerebral palsy (CP): multilevel botulinum toxin type A (BTX-A) injections and multilevel surgery. The purpose of the study was to clarify the differences and the similarities, and common treatment principles of both treatment strategies. Objective three dimensional gait analysis data were studied retrospectively in two patient groups pre- and post-treatment (randomly selected from a group of children that were treated between 1998 and 1999). In the first group, 29 children with CP were managed with BTX-A injections according to an integrated multilevel approach (Molenaers et al., 1999a). A second group of 23 children with CP were managed by a more traditional single event multilevel surgery, also according to an integrated approach. Our aim was to evaluate the differences as well as the similarities between both patient groups, using a set of 56 parameters selected from three-dimensional gait analysis. The unifying concept between management with BTX-A injections and orthopaedic surgery was the adoption of a multilevel approach at one session. The groups demonstrated considerable differences with respect to age, pretreatment condition and amount and level of improvement after treatment. The children who received BTX-A were typically younger, and showed primary gait problems in the distal joints, whereas the children who underwent surgery demonstrated a higher frequency of gait deviations in the transverse plane and had more complications. Although the benefit of both treatments was confirmed by the present study, a difference in the amount and level of improvement was also demonstrated. In conclusion, these treatment modalities should be regarded as complementary rather than mutually exclusive treatments, with both calling for an integrated approach.

Gait analysis in myelomeningocele: possibilities and applications

Gait analysis with a fully integrated laboratory is a relatively new instrument in the armamentarium of the pediatric orthopedic surgeon. The introduction of it has been especially successful in neuromuscular pathology and, particularly, in cerebral palsy. In spina bifida, however, it also enhances substantially the possibilities of detailed analysis of the locomotion problem. It is, furthermore, a very useful instrument in evaluating treatment and in follow-up. With a few examples, this paper tries to show the possibilities and advantages of a gait laboratory in the evaluation of patients with ambulatory spina bifida.

Three-dimensional imaging of acetabular dysplasia: diagnostic value and impact on surgical type classification

OBJECTIVE

To investigate the diagnostic value and the impact on surgical type classification of three-dimensional (3D) images for pre-surgical evaluation of dysplastic hips.

MATERIALS AND METHODS

Three children with a different surgical type of hip dysplasia were investigated with helical computed tomography. For each patient, two-dimensional (2D) images, 3D, and a stereolithographic model of the dysplastic hip were generated. In two separate sessions, 40 medical observers independently analyzed the 2D images (session 1), the 2D and 3D images (session 2), and tried to identify the corresponding stereolithographic hip model. The influence of both image presentation (2D versus 3D images) and observer (degree of experience, radiologist versus orthopedic surgeon) were statistically analyzed. The SL model choice reflected the impact on surgical type classification.

RESULTS

Image presentation was a significant factor whereas the individual observer was not. Three-dimensional images scored significantly better than 2D images (P=0.0003). Three-dimensional imaging increased the correct surgical type classification by 35%.

CONCLUSION

Three-dimensional images significantly improve the pre-surgical diagnostic assessment and surgical type classification of dysplastic hips.

Recommendations for the use of botulinum toxin type A in the management of cerebral palsy

Botulinum toxin type A (BTX-A) is increasingly being used for the treatment of childhood spasticity, particularly cerebral palsy. However, until very recently, all such use in this indication has been unapproved with no generally accepted treatment protocols, resulting in considerable uncertainty and variation in its use as a therapeutic agent. In view of the increasing awareness of, and interest in, this approach to the treatment of spasticity, and also the recent licensing in a number of countries of a BTX-A preparation for treating equinus deformity in children, it would seem timely to establish a framework of guidelines for the safe and efficacious use of BTX-A for treating spasticity in children. This paper represents an attempt, by a group of 15 experienced clinicians and scientists from a variety of disciplines, to arrive at a consensus and produce detailed recommendations as to appropriate patient selection and assessment, dosage, injection technique and outcome measurement. The importance of adjunctive physiotherapy, orthoses and casting is also stressed.

Gait pattern in patients with spastic diplegic cerebral palsy who underwent staged operations

Fifteen patients with spastic diplegic cerebral palsy (CP) were monitored for a mean length of 9.5 years after they underwent staged operations and were evaluated by gait analysis, including joint motion in the sagittal plane and the ground reaction force (GRF) in three dimensions. Results showed an increased hip flexion (132%) at midstance, a reduction of peak knee flexion (PKF) during swing (45%) accompanied by an augmented time of PKF during swing (50%), and an increased dorsiflexion of the ankle during swing (293%) as well as its time during the gait cycle, in comparison with normal values. Moreover, significant decreases of the vertical GRF at the terminal stance and the forward and backward GRF were present. Additionally, it was found that a bilateral popliteal angle < 20 degrees is acceptable in spastic CP. Staged operations gave unpredictable results in the correction of contracture of the hamstrings, the Achilles tendon, and the iliopsoas. The authors are convinced that gait analysis is useful in evaluating these patients and enhances the results of operative treatment, and they have since changed their approach toward multilevel simultaneous corrections.

Popliteal cysts in children: a retrospective study of 62 cases

Popliteal cysts in children are usually asymptomatic and are usually found fortuitously by the parents. This study presents a series of 62 children with popliteal cysts. Among the 51 patients who received no treatment, the cysts had already disappeared at the time of the study in 43 patients; the remaining 8 patients are under 14 years of age and are without complaints. This study confirms the hypothesis that the primary popliteal cyst in children usually disappears before the age of 18. Surgery presents unnecessary risks for the patient ; moreover, the chance of recurrence after surgery is real.

Kinematic and kinetic asymmetry in patients with leg-length discrepancy

The symmetry index (SI), as one of methods to evaluate gait pattern in patients with leg-length discrepancy (LLD), helps to estimate the acceptable range of inequality and to determine symmetry in the kinematic and kinetic data before and after a heel lift, although this parameter has a large standard deviation that undermines its accuracy. Thirty patients with LLD were studied by a motion-analysis system and a force plate. Joint motion of the lower extremity in the sagittal plane, back movement in the coronal plane, and three-dimensional ground-reaction forces (GRFs) were registered. From a linear-regression analysis, a mean value of inequality of 2.33 cm (range, 2.12-2.54) was found to correspond to an acceptable gait symmetry. After a heel lift, the SI of the pelvic tilt at midstance and of the vertical GRF at initial contact increases significantly, but the SI of the medial GRF at terminal stance decreases. Patients with an inequality of a mean value of 0.51 cm determined by palpating bilaterally the top of the iliac crest (the TIC1 subgroup) showed a lesser value of the SI of the center of pressure in the forward direction during stance compared with the group with a mean value of inequality of 1.39 cm (the TIC2 subgroup). As a result of our findings, we conclude that the effect of the amount of correction by a heel lift on gait symmetry is unpredictable.

The sinus tarsi spacer in the operative treatment of flexible flat feet

The results of operative treatment of 45 flexible flat feet (29 patients) using the sinus tarsi spacer are reported. Although radiological improvement in both the talar declination and the ground-navicular distance was found, our patients suffered from pain and functional impairment for an average period of 5 months. An unacceptably high rate of spacer dislocation was noted. Furthermore, the literature indicates spontaneous improvement as the natural history of flexible flat feet. We therefore no longer advise the sinus tarsi spacer as a routine treatment for flexible flat feet.

A new technique for the three-dimensional study of the spine in vitro and in vivo by using a motion-analysis system

We introduce a new method with a motion-analysis system (MAS) to study the vertebral model in vitro. Compared with the currently most accurate technique, roentgen stereophotogrammetric analysis (RSA), the difference between the RSA and the MAS is 0.12 degree +/- 1.64 degrees. An accuracy with an error of 0.08 degree +/- 1.15 degrees is determined by means of an angle gauge. Although a significant difference between the MAS and the goniometer (p = 0.04) is found around the X-axis (theta; transverse plane), it is limited to < 1 degree. The MAS provides an in-depth insight into the mechanism of the three-dimensional rotation at each vertebra in vivo. The backward inclination of the apical vertebra (AV) and forward inclination of the upper-end vertebra (UEV) around the Y-axis (phi) results in a correction of the hypokyphosis shown by the Cobb angle in the sagittal plane. The clockwise rotation of the UEV in the Z-axis (psi) leads to a reduction of the Cobb angle in the frontal plane. Additionally, the MAS as an intraoperative alternative shows different results of the derotation maneuver by the Cotrel-Dubousset instrumentation (CDI) compared with the computed tomography (CT) scan. Our method gives more direct details of the derotation not influenced by patient posture, as observed in the CT scan.

Slipped capital femoral epiphysis: a long-term follow-up, with special emphasis on the capacities for remodeling

We reviewed 59 hips in 44 children with slipped capital femoral epiphysis (SCFE), all treated by in situ pinning. The average clinical and radiographic follow-up was 11.4 years. Fifty-three hips (90%) were rated as either excellent or good. Osteonecrosis or chondrolysis developed in five patients. Postoperative remodeling was noted, not only by a process of local resorption and apposition of bone, but also by correction of the disturbed anatomic axes, in proportion to the severity of the slip, together with global thickening of the femoral neck. We believe that the good long-term results after in situ pinning are the consequence of this important remodeling process.

Split posterior tibial tendon transfer through the interosseus membrane in spastic equinovarus deformity

The split posterior tibial tendon transfer procedure was first reported by Green for correction of equinovarus hindfoot deformity in patients with cerebral palsy. A modification of the split posterior tibial tendon transfer combined with an Achilles tendon lengthening is described in 17 children (21 procedures) with a minimum follow-up of 3 years. This modified technique is indicated in young children with a continuously spastic posterior tibial tendon to correct a dynamic equinovarus. It restores active dorsiflexion when the anterior tibial and extensor muscles are weak. The anterior half of the split tibialis posterior is transferred through the interosseus membrane to the dorsum of the foot. Excellent or good results and two poor results were noted after a mean follow-up of 29 months. In the patients with an excellent or good result, marked improvement of their equinovarus foot deformity in stance and swing phase of gait was seen. In two patients, the procedure failed because of technical errors.

Ground reaction torque and pathway of point of application of ground reaction force during gait of intoeing children

One hundred twenty-four children with intoeing and 80 age-matched controls were investigated with the Kistler force plate. Tr2, reflecting the maximum external rotational ground reaction torque, is reduced by 30% to 40% in all intoeing children. There also is an appreciably shorter pathway of the point of application of the ground reaction force in the Y-direction (from 20% to 25%) and an obvious medial shift of the point of application of the ground reaction force in the X-direction (from 105% to 290%), from heel strike to toe-off as compared with controls. In spontaneous correction of intoeing, point of application of the ground reaction force in the X-direction becomes more close to normal. The "foot progression angle," which can easily be calculated from the force plate measurements to judge the degree of intoeing, is different from the values in the literature.

Femoral derotation for increased hip anteversion. A new surgical technique with a modified Ilizarov frame

We describe a technique of femoral derotation osteotomy performed according to the Ilizarov principles of percutaneous corticotomy and fixation with a frame. We performed 24 femoral osteotomies in 16 patients, four with cerebral palsy and 12 with idiopathic femoral anteversion. All had rapid union and there were few complications. The advantages of the method include early ambulation, good control of rotation and axial alignment, and minimal scarring.

Femoral derotation for increased hip anteversion. A new surgical technique with a modified Ilizarov frame

We describe a technique of femoral derotation osteotomy performed according to the Ilizarov principles of percutaneous corticotomy and fixation with a frame. We performed 24 femoral osteotomies in 16 patients, four with cerebral palsy and 12 with idiopathic femoral anteversion. All had rapid union and there were few complications. The advantages of the method include early ambulation, good control of rotation and axial alignment, and minimal scarring.

A false aneurysm complicating a subcutaneous Achilles tendon lengthening

Subcutaneous lengthening of the Achilles tendon is a routinely used technique in our department. We report a case with a severe complication after this minor procedure in a 13-year-old patient with cerebral palsy. Six weeks after the operation the patient had a false aneurysm caused by a lesion of the posterior tibial artery at the time of surgery. After ligating the artery and draining the false aneurysm, recovery was uneventful. Although subcutaneous lengthening is an easy and reliable operation, one has to keep in mind its possible complications.

The ground reaction force in the gait of intoeing children

One hundred twenty-four intoeing and 80 age-matched normal children were studied using the Kistler force plate. Intoeing gait was usually caused by increased femoral anteversion (IFA), internal tibial torsion (ITT), or metatarsus adductus (MAD). Thirty-five children showing spontaneous correction and a return to normal gait (COR) were singled out. Our results confirmed that there were variations of the ground reaction force (GRF) in three directions in the different groups, particularly in the vertical and medial-lateral components. Alterations of magnitude of GRF or duration of stance phase was found to be significant compared with normal subjects. On this basis, we suggest that dynamic forces are related to the remodeling of the epiphyseal plate or respond to actions of the plantar flexors, although we could not discern a specific correlation between them.

Ultrasound, radiographs, and clinical symptoms in developmental dislocation of the hip: a study of 170 patients

We evaluated ultrasound findings in developmental dislocation of the hip in relation to clinical signs, risk factors, and radiographic measurements. The ultrasound rating was determined according to the method of Graf. An ultrasound rating > IIa was considered abnormal. The risk factors corresponding best with an abnormal ultrasound were breech delivery (42.8%) and familial occurrence (21%). For the clinical findings, the risk factors corresponding best were abduction < 50 (42.5%) and asymmetric skinfolds in patients (26.4%). The radiographic evaluation showed more abnormal findings, but there was no statistical difference between the overall ultrasound and radiographic results.

Normal and abnormal torsional development in children

This study presents findings in a series of 123 children with intoeing gait. The intoeing was caused by increased femoral anteversion (IFA) in 70% of the cases, and internal tibial torsion (ITT) in 30%. Rotation of the hips, thigh-foot angle, Q-angle, and computed tomography measured anteversion and tibial torsion divided the two groups very clearly. In the IFA group, 40.3% of the patients presented with an externally rotated tibia and 59.7% had an internally rotated tibia. In the ITT group, the anteversion was normal for age and the tibial torsion was significantly decreased. Eighty children who corrected their intoeing gait, and of whom 83.4% had IFA, were also reviewed: a decrease in anteversion was observed in 20.5% of the patients; 62.9% showed no decrease in anteversion.