Cerebral palsy (CP), the single largest cause of childhood physical disability, is characterized firstly by a lesion in the immature brain, and secondly by musculoskeletal problems that progress with age. Previous research reported altered muscle properties, such as reduced volume and satellite cell (SC) numbers and hypertrophic extracellular matrix compared to typically developing (TD) children (>10 years). Unfortunately, data on younger CP patients are scarce and studies on SCs and other muscle stem cells in CP are insufficient or lacking. Therefore, it remains difficult to understand the early onset and trajectory of altered muscle properties in growing CP children. Because muscle stem cells are responsible for postnatal growth, repair and remodeling, multiple adult stem cell populations from young CP children could play a role in altered muscle development. To this end, new methods for studying muscle samples of young children, valid to delineate the features and to elucidate the regenerative potential of muscle tissue, are necessary. Using minimal invasive muscle microbiopsy, which was applied in young subjects under general anaesthesia for the first time, we aimed to isolate and characterize muscle stem cell-derived progenitors of TD children and patients with CP. Data of 15 CP patients, 3-9 years old, and 5 aged-matched TD children were reported. The muscle microbiopsy technique was tolerated well in all participants. Through the explant technique, we provided muscle stem cell-derived progenitors from the Medial Gastrocnemius. Via fluorescent activated cell sorting, using surface markers CD56, ALP, and PDGFRa, we obtained SC-derived progenitors, mesoangioblasts and fibro-adipogenic progenitors, respectively. Adipogenic, skeletal, and smooth muscle differentiation assays confirmed the cell identity and ability to give rise to different cell types after appropriate stimuli. Myogenic differentiation in CP SC-derived progenitors showed enhanced fusion index and altered myotube formation based on MYOSIN HEAVY CHAIN expression, as well as disorganization of nuclear spreading, which were not observed in TD myotubes.

PurposeAlthough non-idiopathic clubfeet were long thought to be resistant to non-surgical treatment methods, more studies documenting results on treatment of these feet with the Ponseti method are being published. The goal of this systematic review is to summarize current evidence on treatment of non-idiopathic clubfeet using the Ponseti method.MethodsPubMed and Limo were searched, reference lists of eligible studies were screened and studies that met the inclusion criteria were included. Data on average number of casts, Achilles tendon tenotomy (ATT), initial correction, recurrence, successful treatment at final follow-up and complications were pooled. The Methodological Index for Non-Randomized Studies was used to assess the methodological quality of the selected studies.ResultsIn all, 11 studies were included, yielding a total of 374 non-idiopathic and 801 idiopathic clubfeet. Non-idiopathic clubfeet required more casts (7.2 versus 5.4) and had a higher rate of ATT (89.4% versus 75.7%). Furthermore, these feet had a higher recurrence rate (43.3% versus 11.5%) and a lower rate of successful treatment at final follow-up (69.3% versus 95.0%). Complications were found in 20.3% of the non-­idiopathic cohort. When comparing results between clubfeet associated with myelomeningocele and arthrogryposis, the first group presented with a lower number of casts (5.4 ­versus 7.2) and a higher rate of successful treatment at final follow-up (81.8% versus 58.2%).ConclusionThe Ponseti method is a valuable and non-invasive option in the primary treatment of non-idiopathic clubfeet in young children. Studies with longer follow-up are necessary to evaluate its long-term effect.Level of EvidenceLevel III – systematic review of Level-III studies.This work meets the requirements of the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and ­Meta-Analyses).

FDOFemoral derotation osteotomy GPS Gait Profile Score SDR Selective dorsal rhizotomy AIM To evaluate the long-term outcome of selective dorsal rhizotomy (SDR) on gait and the influence of previous femoral derotation osteotomy (FDO).METHOD In a retrospective cohort study of 29 children (16 females, 13 males) with spastic diplegic cerebral palsy, 14 children received FDO before SDR, whereas 15 children with moderate or near-normal internal femoral rotation during gait received only SDR. Threedimensional gait data were obtained pre-FDO, pre-SDR, 1 year post-SDR, and 3 to 5 years post-SDR, to study the Gait Profile Score (GPS), pelvic tilt, and knee and hip kinematics. A mixed analysis of variance with the repeated measure 'time' was performed between different time points for each group.RESULTS Children who first underwent FDO and then SDR started with a more complex gait pathology but showed fewer gait deviations 3 to 5 years post-SDR, compared to children who only underwent SDR. This was reflected by a lower GPS and pelvic tilt, as well as less knee flexion in stance.

Hereditary spastic paraplegia (HSP) is a neurological, genetic disorder that predominantly presents with lower limb spasticity and muscle weakness. Pediatric pure HSP types with infancy or childhood symptom onset resemble in clinical presentation to children with bilateral spastic cerebral palsy (SCP). Hence, treatment approaches in these patient groups are analogous. Altered muscle characteristics, including reduced medial gastrocnemius (MG) muscle growth and hyperreflexia have been quantified in children with SCP, using 3D-freehand ultrasound (3DfUS) and instrumented assessments of hyperreflexia, respectively. However, these muscle data have not yet been studied in children with HSP. Therefore, we aimed to explore these MG muscle characteristics in HSP and to test the hypothesis that these data differ from those of children with SCP and typically developing (TD) children. A total of 41 children were retrospectively enrolled including (1) nine children with HSP (ages of 9–17 years with gross motor function levels I and II), (2) 17 age-and severity-matched SCP children, and (3) 15 age-matched typically developing children (TD). Clinically, children with HSP showed significantly increased presence and severity of ankle clonus compared with SCP (p = 0.009). Compared with TD, both HSP and SCP had significantly smaller MG muscle volume normalized to body mass (p ≤ 0.001). Hyperreflexia did not significantly differ between the HSP and SCP group. In addition to the observed pathological muscle activity for both the low-velocity and the change in high-velocity and low-velocity stretches in the two groups, children with HSP tended to present higher muscle activity in response to increased stretch velocity compared with those with SCP. This exploratory study is the first to reveal MG muscle volume deficits in children with HSP. Moreover, high-velocity-dependent hyperreflexia and ankle clonus is observed in children with HSP. Instrumented impairment assessments suggested similar altered MG muscle characteristics in pure HSP type with pediatric onset compared to bilateral SCP. This finding needs to be confirmed in larger sample sizes. Hence, the study results might indicate analogous treatment approaches in these two patient groups.

Purpose By means of a case series we wanted to describe and correlate the clinical and imaging features of bone marrow oedema syndrome (BMOS) of the foot and ankle in children. Methods A retrospective data study was performed on patients born on or after 01 January 2001 who underwent multiple MRI scans of the foot and ankle for pain symptoms. Six patients who presented with increased signal intensity on T2-weighted MR imaging without any underlying causes or concomitant pathology were included. Results All patients, three boys and three girls with a mean age of 11 years (8 to 14), displayed patchy areas of increased signal intensity on T2-weighted and turbo inversion recovery magnitude (TIRM) images. On average, six tarsal bones were involved (4 to 8). In all patients, treatment consisted of rest and/or protected weight-bearing. The mean time for symptoms to improve during treatment was 6 months (1 to 16). The mean duration of treatment was nine months (3 to 16). In all patients clinical and imaging symptoms were strongly correlated and regressed in time. Conclusion BMOS as a pathological entity should be considered in paediatric patients with foot and ankle pain without a clear underlying cause, and characteristic T2-weighted and TIRM signal intensity increase on MRI images. As BMOS is transient and self-limiting, conservative treatment is advised while the oedema regresses. An early diagnosis of this pathology could prevent unnecessary diagnostic investigations and invasive treatments. Level of Evidence IV