MDF Maximum dorsiflexion MPF Maximum plantarflexion PCSA Physiological cross-sectional area AIM The aim of this article was to compare medial gastrocnemius muscle volume, physiological cross-sectional area (PCSA), muscle length, fascicle length, and pennation angle in children aged 2 to 5 years with spastic cerebral palsy (CP) and in typically developing children.METHOD Fifteen children with spastic CP (11 males, four females; mean age 45mo [SD 15mo]; five with hemiplega; 10 with diplega; 10 classified at Gross Motor Function Classification System (GMFCS) level I, five at GMFCS level II) and 20 typically developing children (11 males, nine females; mean age 48mo [SD 14mo]) participated in the study. Individuals with spastic CP were included if they had a minimum range of motion of 0°ankle dorsiflexion with the knee extended and were excluded if they had had previous botulinum toxin treatment to the calf muscles or previous calf surgery. Typically developing children were included if they were able to walk independently and were excluded if there was a history of previous lower leg injury or other developmental disorder affecting the lower limb. Freehand two-dimensional and threedimensional ultrasound was used to assess muscle properties of the relaxed medial gastrocnemius muscle at three ankle joint angles: maximum dorsiflexion, neutral and maximum plantarflexion. PCSA was calculated as a function of muscle volume and muscle fascicle length and pennation angle was recorded at the neutral ankle joint angle.RESULTS Medial gastrocnemius muscle volume was 22% lower in the group with spastic CP than in the typically developing group, which in the absence of significant group differences in neutral fascicle length gave rise to an equivalent reduction in PCSA for the group with spastic CP. Significant positive correlations were found between muscle volume and age (r=0.63-0.65) and between muscle length and age (r=0.72-0.81) in both groups. Maximum ankle dorsiflexion angle was also reduced in the group with spastic CP (8°) compared with the typically developing group (26°). INTERPRETATIONThe observed reduction in muscle PCSA in the group with spastic CP would be expected to contribute to the clinically observed muscle weakness in spastic CP and suggests the need for early intervention in order to minimize loss of muscle PCSA in spastic CP.Spastic cerebral palsy (CP) is a group of non-progressive motor impairment syndromes that occur secondary to lesions of the brain in the early stages of development.1 Spasticity is the key feature of spastic CP and is neural in origin. However, it is clear that spastic muscle also undergoes significant morphological and structural alterations during development. Involved muscles often shorten to create muscle contractures, which contribute to increased joint stiffness and reduced joint range of motion and may contribute to reduced voluntary strength. These impairments progress over time, and limb movement and general functional ability often decline.2-4 As the secondary effects of spas...

During the past 25 years, botulinum toxin type A (BoNT-A) has become the most widely used medical intervention in children with cerebral palsy. In this review we consider the gaps in our knowledge in the use of BoNT-A and reasons why muscle morphology and function in children with cerebral palsy are impaired. We review limitations in our knowledge regarding the mechanisms underlying the development of contractures and the difficulty in preventing them. It is clear from this review that injection of BoNT-A in the large muscles of both the upper and lower limbs of children with cerebral palsy will result in a predictable decrease in muscle activity, which is usually reported as a reduction in spasticity, for between 3 and 6 months. These changes are noted by the use of clinical tools such as the Modified Ashworth Scale and the Modified Tardieu Scale. Decreased muscle over-activity usually results in improved range of motion in distal joints. Injection of the gastrocnemius muscle for toe-walking in a child with hemiplegia or diplegia usually has the effect of increasing the passive range of dorsiflexion at the ankle. In our review, we found that this may result in a measurable improvement in gait by the use of observational gait scales or gait analysis, in some children. However, improvements in gait function are not always achieved and are small in magnitude and short lived. We found that some of the differences in outcomes in clinical trials may relate to the use of adjunctive interventions such as serial casting, orthoses, night splints and intensive therapy. We note that the majority of clinical trials of the use of BoNT-A in children with cerebral palsy have focussed on a single injection cycle and this is insufficient to understand the balance between benefit and harm. Most outcomes were reported in terms of changes in muscle tone and there were fewer studies with robust methodology that reported improvements in function. Changes in the domains of activities and participation have rarely been reported in studies to date. There were no clinical reviews to date that consider the findings of studies in human volunteers and in experimental animals and their relevance to clinical protocols. In this review we found that studies in human volunteers and in experimental animals show muscle atrophy after an injection of BoNT-A for at least 12 months. Muscle atrophy was accompanied by loss of contractile elements in muscle and replacement with fat and connective tissue. It is not currently known if these changes, mediated at a molecular level, are reversible. We conclude that there is a need to revise clinical protocols by using BoNT-A more thoughtfully, less frequently and with greatly enhanced monitoring of the effects on injected muscle for both short-term and long-term benefits and harms.

Purpose This study was a 12-month prospective investigation of changes in the medial gastrocnemius (MG) muscle morphology in children aged 2-5 years with spastic cerebral palsy (CP) who had received no previous intramuscular injections of botulinum neurotoxin type-A (BoNT-A) and were randomised to receive either single or multiple (three) BoNT-A injections to the gastrocsoleus. MG morphological changes were compared to age-matched typically developing (TD) peers. Methods Thirteen children with spastic CP with a mean age of 45 (15) months and 18 TD children with a mean age of 48 (14) months participated in the study. The principal outcome measures were MG muscle volume, fascicle length, pennation angle and physiological cross-sectional area (PCSA), which were obtained using 2D and 3D ultrasound.Results The single and multiple injection frequency groups significantly increased MG muscle volume at 12 months relative to the baseline by 13 and 15 %, respectively. There were no significant differences in the MG muscle volume 28.5 (12.3) versus 30.3 (3.8) ml, fascicle length 48.0 (10.4) versus 44.8 (1.2) mm or PCSA 7.0 (1.2) versus 6.6 (1.7) cm 2 between the single and multiple injection groups, respectively, at 12 months follow-up. The change in MG muscle volume in the single and multiple injection groups was significantly lower than the TD peers by 66 and 60 %, respectively. Interpretation In young children with spastic CP, naive to BoNT-A treatment, MG muscle growth over 12 months does not appear to be influenced by intramuscular BoNT-A injection frequency. However, MG muscle growth in the spastic CP groups was significantly lower than the agematched TD peers. It is unclear whether this is an effect of intramuscular BoNT-A injections or reduced growth rates in children with spastic CP in general. 123J Child Orthop (2013) 7:425-433 DOI 10.1007 investigations and longitudinal studies with multiple measurement time points are required in order to determine the influence of BoNT-A treatment on muscle physiological and mechanical growth factors in young children with spastic CP.

PurposeBotulinum toxin-A (or Botox) is widely used for the management of equinus gait in children with cerebral palsy but few recent studies have included instrumented gait analysis.MethodsThis was a prospective cohort study. Gait analysis was performed four weeks before and four weeks after Botulinum toxin-A injection for spastic equinus to detect the maximum effects on gait kinematics. Outcome measures included the Gait Profile Score (GPS), the Gait Variable Score (GVS) for the ankle, maximal ankle dorsiflexion and maximal knee extension at midstance.ResultsIn all, 37 children participated (20 boys); mean age five years seven months (4 years 1 month to 8 years 2 months); 19 with unilateral and 18 bilateral involvement. At a mean four weeks post-injection, the GPS and ankle GVS were unchanged. However maximum ankle dorsiflexion increased for the whole group; median 7.7° (confidence interval (CI) 4° to 10.6°) to 11.5° (CI 7.7° to 12.9°), p = 0.02. Maximum midstance knee extension was unchanged for the whole group, but median knee flexion increased in children with bilateral involvement; 10.9° (CI 7.4° to 20.8°) to 16.5° (CI 8.4° to 19.7°), p = 0.58.ConclusionInjections of the gastrocsoleus for spastic equinus did not result in objective improvements in overall gait. Improvements in ankle dorsiflexion for children with bilateral involvement may be offset by deterioration at the knee.Level of EvidenceII - prospective cohort study, before and after intervention

This article presents a classification of lower limb musculoskeletal pathology (MSP) for ambulant children with cerebral palsy (CP) to identify key features from infancy to adulthood. The classification aims to improve communication, and to guide referral for interventions, which if timed appropriately, may optimise long-term musculoskeletal health and function. Consensus was achieved by discussion between staff in a Motion Analysis Laboratory (MAL). A four-stage classification system was developed: Stage 1: Hypertonia: Abnormal postures are dynamic. Stage 2: Contracture: Fixed shortening of one or more muscle-tendon units. Stage 3: Bone and joint deformity: Torsional deformities and/or joint instability (e.g., hip displacement or pes valgus), usually accompanied by contractures. Stage 4: Decompensation: Severe pathology where restoration of optimal joint and muscle-tendon function is not possible. Reliability of the classification was tested using the presentation of 16 clinical cases to a group of experienced observers, on two occasions, two weeks apart. Reliability was found to be very good to excellent, with mean Fleiss’ kappa ranging from 0.72 to 0.84. Four-stages are proposed to classify lower limb MSP in children with CP. The classification was reliable in a group of clinicians who work together. We emphasise the features of decompensated MSP in the lower limb, which may not always benefit from reconstructive surgery and which can be avoided by timely intervention.

FAQRESULTS Forty-two children entered the trial with 21 participants randomized to each group.There were three withdrawals and two children received serial casting midway through the trial. There was no significant difference in passive dorsiflexion between 12-monthly and 4-monthly regimens (p=0.41). There were also no significant between group differences on secondary outcome measures. There were no serious adverse events -the rate was 1.2 adverse events per child per year in the 12-monthly group and 2.2 adverse events per child per year in the 4-monthly group. Subgroup analysis revealed a significant difference in passive dorsiflexion between children with hemiplegia and diplegia (p=0.01).

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ABBREVIATIONS MCIDMinimal clinically important difference PADKE Passive ankle dorsiflexion range with the knee extended AIM The aims of this study were to (1) determine whether an instrumented measure will reduce measurement error to less than 5°in children with cerebral palsy (CP), (2) determine agreement and reliability of this instrumented measure in both conscious and anaesthetized participants, and (3) compare the method with previously reported measures.METHOD Thirty-four ambulant children (15 males, 19 females), aged 3 to 9 years, with spastic CP were studied in a tertiary-care paediatric hospital (21 with hemiplegia, 11 with diplegia, and two with quadriplegia). The majority of children functioned at Gross Motor Function Classification System level I (n=11) or II (n=18), with five children at level III. Ankle dorsiflexion at 50% bodyweight was photographed and measured. Each child was measured when conscious and when under mask anaesthesia by two experienced assessors. RESULTS