Joint and muscle assessments of the separate effects of Botulinum NeuroToxin-A and lower-leg casting in children with cerebral palsy

Botulinum NeuroToxin-A (BoNT-A) injections to the medial gastrocnemius (MG) and lower-leg casts are commonly combined to treat ankle equinus in children with spastic cerebral palsy (CP). However, the decomposed treatment effects on muscle or tendon structure, stretch reflexes, and joint are unknown. In this study, BoNT-A injections to the MG and casting of the lower legs were applied separately to gain insight into the working mechanisms of the isolated treatments on joint, muscle, and tendon levels. Thirty-one children with spastic CP (GMFCS I-III, age 7.4 +/- 2.6 years) received either two weeks of lower-leg casts or MG BoNT-A injections. During full range of motion slow and fast passive ankle rotations, joint resistance and MG stretch reflexes were measured. MG muscle and tendon lengths were assessed at resting and at maximum dorsiflexion ankle angles using 3D-freehand ultrasound. Treatment effects were compared using non-parametric statistics. Associations between the effects on joint and muscle or tendon levels were performed using Spearman correlation coefficients (p < 0.05). Increased joint resistance, measured during slow ankle rotations, was not significantly reduced after either treatment. Additional joint resistance assessed during fast rotations only reduced in the BoNT-A group (-37.6%, p = 0.013, effect size = 0.47), accompanied by a reduction in MG stretch reflexes (-70.7%, p = 0.003, effect size = 0.56). BoNT-A increased the muscle length measured at the resting ankle angle (6.9%, p = 0.013, effect size = 0.53). Joint angles shifted toward greater dorsiflexion after casting (32.4%, p = 0.004, effect size = 0.56), accompanied by increases in tendon length (5.7%, p = 0.039, effect size = 0.57; r = 0.40). No associations between the changes in muscle or tendon lengths and the changes in the stretch reflexes were found. We conclude that intramuscular BoNT-A injections reduced stretch reflexes in the MG accompanied by an increase in resting muscle belly length, whereas casting resulted in increased dorsiflexion without any changes to the muscle length. This supports the need for further investigation on the effect of the combined treatments and the development of treatments that more effectively lengthen the muscle

Reliability of Processing 3-D Freehand Ultrasound Data to Define Muscle Volume and Echo-intensity in Pediatric Lower Limb Muscles with Typical Development or with Spasticity

This investigation assessed the processer reliability of estimating muscle volume and echo-intensity of the rectus femoris, tibialis anterior and semitendinosus. The muscles of 10 typically developing children (8.15 [1.40] y) and 15 children with spastic cerebral palsy (7.67 [3.80] y; Gross Motor Function Classification System I = 5, II = 5, III = 5) were scanned with 3-D freehand ultrasonography. For the intra-processer analysis, the intra-class correlations coefficients (ICCs) for muscle volume ranged from 0.943–0.997, with relative standard errors of measurement (SEM%) ranging from 1.24%–8.97%. For the inter-processer analysis, these values were 0.853 to 0.988 and 3.47% to 14.02%, respectively. Echo-intensity had ICCs >0.947 and relative SEMs <4% for both analyses. Muscle volume and echo-intensity can be reliably extracted for the rectus femoris, semitendinosus and tibialis anterior in typically developing children and children with cerebral palsy. The need for a single processer to analyze all data is dependent on the size of the expected changes or differences

Raw Data (Anonymised)

<p>The data pertaines to the article "The Intra- and Inter-Rater Reliability of an Instrumented Spasticity Assessment in Children with Cerebral Palsy". The values were used to calculate the various components of reliability.</p

In vivo muscle behaviour in cerebral palsy with an equinus gait: are we on track?

The article focuses on the muscle behaviour in children with cerebral palsy (CP) with an equinus gait pattern. It relates the study "Medial gastrocnemius and soleus muscle-tendon unit, fascicle and tendon interaction during walking in children with cerebral palsy," by L. Barber and colleagues which examines in vivo medial gastrocnemius fascicle behaviour in CP patients. The results of the study shows that joint kinematics does not affect muscle-tendon unit behaviour

A rare complication of a rare pediatric injury: Transient drop foot following a floating knee injury

Floating Knee is a rare injury caused by high velocity, and has rarely been described in children. The purpose of this report is to present a case of a six-year-old female after a fall down three and a half flights of stairs, suffering from this rare injury and a rare complication, and her rehabilitation. She suffered fractures of the femur and tibia (Floating Knee type), and was operated on the day of the injury with closed reduction and internal fixation (CRIF). Following the operation, painful drop-foot was evident, related to the fractured bone pressure on the sciatic nerve and a very high level of anxiety. The patient was transferred to a rehabilitation hospital, where she received a total of about 350 physical therapy, hydrotherapy, psychology and occupational therapy treatments over a period of one year. Treatment also consisted of an ankle-foot orthosis (AFO) and transcutaneous electrical stimulation, and were assisted with examinations at the motion analysis laboratory using surface electromyography. The combined orthopedic and physical therapy treatment, and cooperation with psychology in the intervention and training for the care team, enabled achievement of all rehabilitation goals. The patient returned to a high functional level and full participation in daily life activities with her peers, without the need for the AFO or further treatment in the community. A re-examination after about six months showed continued functional improvement according to objective indicators. This case raises awareness of rare injuries and complications in pediatric orthopedic patients, that require multidisciplinary rehabilitation treatment and cooperation between the surgical and rehabilitation teams. Closed injury of the sciatic nerve can be followed for a long period without additional invasive studies or formal nerve exploration, and complete recovery can be achieved

The reliability of measuring medial gastrocnemius muscle-tendon unit lengths during gait

Background Ultrasound imaging combined with 3D motion analysis allows for in-vivo assessment of muscle-tendon unit lengths during gait. The clinical relevance of analysing the medial gastrocnemius (MG) and Achilles muscle-tendon junction (MTJ), MG mid-muscle belly fascicles (FAS) and muscle thickness was shown. However, their reliability error estimations over the gait cycle is unknown. Research question What are the intra- and inter-session errors associated with extracting MG belly, thickness, FAS and tendon lengths using ultrasound during gait in healthy participants? Methods 3D gait analysis was carried out in ten healthy adults as they walked on an instrumented treadmill at a comfortable walking speed. An ultrasound probe was secured on the leg and tracked by 3D motion analysis. Images were collected during two walking trials with the probe on the MG muscle-belly to estimate FAS lengths and muscle thickness, and during two trials with the probe on the MTJ to estimate muscle-belly and tendon lengths. A second session was performed after 5 ± 4 days where a different operator placed the ultrasound probe. The standard deviation (SD) of absolute and relative lengths changes during the gait cycle over different trials were calculated per participant. SD values averaged over participants represented intra- and inter-session errors. Results For all assessed variables, the intra-session errors were <2.2 mm, except for the FAS lengths (3.1 mm). The inter-session errors were larger than the intra-session, with the highest values found for the absolute muscle-tendon unit lengths (5.6 mm). Relative length errors were smaller than absolute length errors. Significance Intra-session errors, which may reflect natural variability and data processing errors, seem more critical when extracting absolute FAS than muscle-tendon lengths. Standardized probe positioning on the MTJ between sessions may improve the inter-session reliability. Expressing the lengths relative to their lengths as the beginning of the gait cycle reduces the inter-session errors.peerReviewe

Validity of efficient ultrasound methodologies to measure muscle and tendon lengths

status: publishe

3D FREEHAND ULTRASOUND: RECONSTRUCTION AND FEATURES EXTRACTION IN LOWER LIMB MUSCLE

Ultrasound systems can be enhanced to combine 3D data and corresponding spatial information. This approach, called 3D freehand Ultrasound (3DFUS), uses ultrasound (US) images and the corresponding pose of the transducer with the purpose of reconstructing the 3D morphology for large anatomical parts. So far, this 3D reconstruction has only limited clinical use as the procedure is not widely accessible and features extraction is very time consuming. Our current work is aimed at developing a new tool for image reconstruction and to optimizing the features extraction process in 3DFUS.status: accepte