Sleep shapes the associative structure underlying pattern completion in multielement event memory.

Sleep supports the consolidation of episodic memory. It is, however, a matter of ongoing debate how this effect is established, because, so far, it has been demonstrated almost exclusively for simple associations, which lack the complex associative structure of real-life events, typically comprising multiple elements with different association strengths. Because of this associative structure interlinking the individual elements, a partial cue (e.g., a single element) can recover an entire multielement event. This process, referred to as pattern completion, is a fundamental property of episodic memory. Yet, it is currently unknown how sleep affects the associative structure within multielement events and subsequent processes of pattern completion. Here, we investigated the effects of post-encoding sleep, compared with a period of nocturnal wakefulness (followed by a recovery night), on multielement associative structures in healthy humans using a verbal associative learning task including strongly, weakly, and not directly encoded associations. We demonstrate that sleep selectively benefits memory for weakly associated elements as well as for associations that were not directly encoded but not for strongly associated elements within a multielement event structure. Crucially, these effects were accompanied by a beneficial effect of sleep on the ability to recall multiple elements of an event based on a single common cue. In addition, retrieval performance was predicted by sleep spindle activity during post-encoding sleep. Together, these results indicate that sleep plays a fundamental role in shaping associative structures, thereby supporting pattern completion in complex multielement events.

Sleep promotes T-cell migration towards CCL19 via growth hormone and prolactin signaling in humans.

Sleep strongly supports the formation of adaptive immunity, e.g., after vaccination. However, the underlying mechanisms remain largely obscure. Here we show in healthy humans that sleep compared to nocturnal wakefulness specifically promotes the migration of various T-cell subsets towards the chemokine CCL19, which is essential for lymph-node homing and, thus, for the initiation and maintenance of adaptive immune responses. Migration towards the inflammatory chemokine CCL5 remained unaffected. Incubating the cells with plasma from sleeping participants likewise increased CCL19-directed migration, an effect that was dependent on growth hormone and prolactin signaling. These findings show that sleep selectively promotes the lymph node homing potential of T cells by increasing hormonal release, and thus reveal a causal mechanism underlying the supporting effect of sleep on adaptive immunity in humans.

Sleep consolidates stimulus-response learning.

Performing a motor response to a sensory stimulus creates a memory trace whose behavioral correlates are classically investigated in terms of repetition priming effects. Such stimulus-response learning entails two types of associations that are partly independent: (1) an association between the stimulus and the motor response and (2) an association between the stimulus and the classification task in which it is encountered. Here, we tested whether sleep supports long-lasting stimulus-response learning on a task requiring participants (1) for establishing stimulus-classification associations to classify presented objects along two different dimensions ("size" and "mechanical") and (2) as motor response (action) to respond with either the left or right index finger. Moreover, we examined whether strengthening of stimulus-classification associations is preferentially linked to nonrapid eye movement (non-REM) sleep and strengthening of stimulus-action associations to REM sleep. We tested 48 healthy volunteers in a between-subjects design comparing postlearning retention periods of nighttime sleep versus daytime wakefulness. At postretention testing, we found that sleep supports consolidation of both stimulus-action and stimulus-classification associations, as indicated by increased reaction times in "switch conditions"; that is, when, at test, the acutely instructed classification task and/or correct motor response for a given stimulus differed from that during original learning. Polysomnographic recordings revealed that both kinds of associations were correlated with non-REM spindle activity. Our results do not support the view of differential roles for non-REM and REM sleep in the consolidation of stimulus-classification and stimulus-action associations, respectively.

Determining the development stage of the ossification centers around the elbow may aid in deciding whether to use ESIN or not in adolescents' forearm shaft fractures.

Background and purpose - Elastic stable intramedullary nailing (ESIN) is the preferred method of operative stabilization of unstable pediatric forearm shaft fractures. However, the decision whether to use ESIN or open reduction and internal fixation (ORIF) in older children or teenagers is not always straightforward. We hypothesized that the development stage of the elbow would aid in evaluating the eligibility of the patient for ESIN.Patients and methods - All eligible children, aged <16 years who were treated with ESIN in Oulu University Hospital, during 2010-2019 were included (N = 70). The development stages of 4 ossification centers were assessed according to the Sauvegrain and Diméglio scoring. The proportion of impaired union vs. union was analyzed according to bone maturity, by using the optimal cutoff-points determined with receiver operating characteristics (ROC).Results - Development stage ≥ 6 in the olecranon was associated with impaired union in 20% of patients, compared with none in stages 1-5 (95% CI of difference 8% to 24%). Trochlear ossification center ≥ 4 was associated with impaired union in 17% of patients (CI of difference 7% to 36%) and lateral condyle ≥ 6 in 13% of patients (CI of difference 3.4% to 30%). Proximal radial head ≥ 5.5 was associated with impaired union in 18% of patients (CI of difference 7% to 39%).Interpretation - Recognizing the rectangular or fused olecranon ossification center, referring to stage ≥ 6, was in particular associated with impaired fracture healing. This finding may aid clinicians to consider between ESIN and plating, when treating forearm shaft fracture of an older child or teenager.

Sleep Strengthens Predictive Sequence Coding.

Predictive-coding theories assume that perception and action are based on internal models derived from previous experience. Such internal models require selection and consolidation to be stored over time. Sleep is known to support memory consolidation. We hypothesized that sleep supports both consolidation and abstraction of an internal task model that is subsequently used to predict upcoming stimuli. Human subjects (of either sex) were trained on deterministic visual sequences and tested with interleaved deviant stimuli after retention intervals of sleep or wakefulness. Adopting a predictive-coding approach, we found increased prediction strength after sleep, as expressed by increased error rates to deviant stimuli, but fewer errors for the immediately following standard stimuli. Sleep likewise enhanced the formation of an abstract sequence model, independent of the temporal context during training. Moreover, sleep increased confidence for sequence knowledge, reflecting enhanced metacognitive access to the model. Our results suggest that sleep supports the formation of internal models which can be used to predict upcoming events in different contexts.SIGNIFICANCE STATEMENT To efficiently interact with the ever-changing world, we predict upcoming events based on similar previous experiences. Sleep is known to benefit memory consolidation. However, it is not clear whether sleep specifically supports the transformation of past experience into predictions of future events. Here, we find that, when human subjects sleep after learning a sequence of predictable visual events, they make better predictions about upcoming events compared with subjects who stayed awake for an equivalent period of time. In addition, sleep supports the transfer of such knowledge between different temporal contexts (i.e., when sequences unfold at different speeds). Thus, sleep supports perception and action by enhancing the predictive utility of previous experiences.

[Ankle sprain in youth athlete]. / Entorse de la cheville chez le jeune sportif.

Lateral ankle sprain is the most frequent musculoskeletal injury in the young athlete. Myths, dogma and common belief are regularly encountered when discussing this injury, for which the scientific literature does not prevail yet. In the youth, the growing skeleton further influences the diagnosis and therapeutic processes, as well as the healing potential. For the athlete, a fast recovery and return to sports without recurrence are a priority. In this specific context, an integrated management of the ankle sprain in the young athlete must be based on an adequate diagnosis, a sound knowledge of pediatrics pitfalls and peer-reviewed physiotherapy recommendations and consensus statements.

Lésion musculosquelettique la plus fréquente chez le jeune sportif, l'entorse de la cheville n'en reste pas moins un sujet médical où foisonnent les idées reçues, les dogmes et les mythes que la science a du mal à faire disparaître. Lorsqu'elle affecte un jeune, les pièges du squelette en croissance et le potentiel de guérison sont des éléments supplémentaires influençant le processus diagnostique et thérapeutique. Chez le sportif, le retour rapide à l'entraînement en évitant tout risque de récidive est une priorité. Dans ce contexte, la prise en charge intégrée de l'entorse de la cheville chez le jeune sportif doit être basée sur un bon diagnostic, une connaissance des pièges pédiatriques et des recommandations physiothérapeutiques basées sur l'évidence et les avis de consensus.

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF).

Background and purpose - To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the upper extremities of a representative population of children classified according to the PCCF. Patients and methods - We included children and adolescents (0-17 years old) diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at the university hospitals in Bern and Lausanne (Switzerland). Patient charts were retrospectively reviewed and fractures were classified from standard radiographs. Results - Of 2,292 upper extremity fractures in 2,203 children and adolescents, 26% involved the humerus and 74% involved the forearm. In the humerus, 61%, and in the forearm, 80% of single distal fractures involved the metaphysis. In adolescents, single humerus fractures were more often epiphyseal and diaphyseal fractures, and among adolescents radius fractures were more often epiphyseal fractures than in other age groups. 47% of combined forearm fractures were distal metaphyseal fractures. Only 0.7% of fractures could not be classified within 1 of the child-specific fracture patterns. Of the single epiphyseal fractures, 49% were Salter-Harris type-II (SH II) fractures; of these, 94% occurred in schoolchildren and adolescents. Of the metaphyseal fractures, 58% showed an incomplete fracture pattern. 89% of incomplete fractures affected the distal radius. Of the diaphyseal fractures, 32% were greenstick fractures. 24 Monteggia fractures occurred in pre-school children and schoolchildren, and 2 occurred in adolescents. Interpretation - The pattern of pediatric fractures in the upper extremity can be comprehensively described according to the PCCF. Prospective clinical studies are needed to determine its clinical relevance for treatment decisions and prognostication of outcome.

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF).

Background and purpose - To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the lower extremities of a representative population of children classified according to the PCCF. Patients and methods - We included patients up to the age of 17 who were diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at either of 2 tertiary care university hospitals in Switzerland. Patient charts were retrospectively reviewed. Results - More lower extremity fractures occurred in boys (62%, n = 341). Of 548 fractured long bones in the lower extremity, 25% involved the femur and 75% the lower leg. The older the patients, the more combined fractures of the tibia and fibula were sustained (adolescents: 50%, 61 of 123). Salter-Harris (SH) fracture patterns represented 66% of single epiphyseal fractures (83 of 126). Overall, 74 of the 83 SH patterns occurred in the distal epiphysis. Of all the metaphyseal fractures, 74 of 79 were classified as incomplete or complete. Complete oblique spiral fractures accounted for 57% of diaphyseal fractures (120 of 211). Of all fractures, 7% (40 of 548) were classified in the category "other", including 29 fractures that were identified as toddler's fractures. 5 combined lower leg fractures were reported in the proximal metaphysis, 40 in the diaphysis, 26 in the distal metaphysis, and 8 in the distal epiphysis. Interpretation - The PCCF allows classification of lower extremity fracture patterns in the clinical setting. Re-introduction of a specific code for toddler's fractures in the PCCF should be considered.

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF).

Background and purpose - The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF) describes the localization and morphology of fractures, and considers severity in 2 categories: (1) simple, and (2) multifragmentary. We evaluated simple and multifragmentary fractures in a large consecutive cohort of children diagnosed with long bone fractures in Switzerland. Patients and methods - Children and adolescents treated for fractures between 2009 and 2011 at 2 tertiary pediatric surgery hospitals were retrospectively included. Fractures were classified according to the AO PCCF. Severity classes were described according to fracture location, patient age and sex, BMI, and cause of trauma. Results - Of all trauma events, 3% (84 of 2,730) were diagnosed with a multifragmentary fracture. This proportion was age-related: 2% of multifragmentary fractures occurred in school-children and 7% occurred in adolescents. In patients diagnosed with a single fracture only, the highest percentage of multifragmentation occurred in the femur (12%, 15 of 123). In fractured paired radius/ulna bones, multifragmentation occurred in 2% (11 of 687); in fractured paired tibia/fibula bones, it occurred in 21% (24 of 115), particularly in schoolchildren (5 of 18) and adolescents (16 of 40). In a multivariable regression model, age, cause of injury, and bone were found to be relevant prognostic factors of multifragmentation (odds ratio (OR) > 2). Interpretation - Overall, multifragmentation in long bone fractures in children was rare and was mostly observed in adolescents. The femur was mostly affected in single fractures and the lower leg was mostly affected in paired-bone fractures. The clinical relevance of multifragmentation regarding growth and long-term functional recovery remains to be determined.

[News in paediatrics]. / Pédiatrie.

Every pediatrician will be confronted with newborns oryoung infants with skin lesions in proximity of the vertebral column. It is important not to miss a spinal dysraphism because of the risk of meningeal infection or of the possible presence of a tethered cord. A practical algorithm is presented. Non-accidental injury in young infants and toddlers is not rare but difficult to detect. Bruises and fractures are highly suspicious for non-accidental injury and should trigger specific investigations. Emergency departments and hospitals are switching from hypotonic to isotonic solutions as maintenance infusions of children. They reduce the risk of hyponatremia without increasing that of hypernatremia, and they should be used preferentially in the majority of pediatric clinical settings.

An epidemiological evaluation of pediatric long bone fractures - a retrospective cohort study of 2716 patients from two Swiss tertiary pediatric hospitals.

BACKGROUND: Children and adolescents are at high risk of sustaining fractures during growth. Therefore, epidemiological assessment is crucial for fracture prevention. The AO Comprehensive Injury Automatic Classifier (AO COIAC) was used to evaluate epidemiological data of pediatric long bone fractures in a large cohort. METHODS: Data from children and adolescents with long bone fractures sustained between 2009 and 2011, treated at either of two tertiary pediatric surgery hospitals in Switzerland, were retrospectively collected. Fractures were classified according to the AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF). RESULTS: For a total of 2716 patients (60% boys), 2807 accidents with 2840 long bone fractures (59% radius/ulna; 21% humerus; 15% tibia/fibula; 5% femur) were documented. Children's mean age (SD) was 8.2 (4.0) years (6% infants; 26% preschool children; 40% school children; 28% adolescents). Adolescent boys sustained more fractures than girls (p < 0.001). The leading cause of fractures was falls (27%), followed by accidents occurring during leisure activities (25%), at home (14%), on playgrounds (11%), and traffic (11%) and school accidents (8%). There was boy predominance for all accident types except for playground and at home accidents. The distribution of accident types differed according to age classes (p < 0.001). Twenty-six percent of patients were classed as overweight or obese - higher than data published by the WHO for the corresponding ages - with a higher proportion of overweight and obese boys than in the Swiss population (p < 0.0001). CONCLUSION: Overall, differences in the fracture distribution were sex and age related. Overweight and obese patients seemed to be at increased risk of sustaining fractures. Our data give valuable input into future development of prevention strategies. The AO PCCF proved to be useful in epidemiological reporting and analysis of pediatric long bone fractures.

Pediatric emergencies admitted in the resuscitation room of a Swiss university hospital.

OBJECTIVES: Pediatric resuscitation is an intense, stressful, and challenging process. The aim of this study was to review the life-threatening pediatric (LTP) emergencies admitted in a Swiss university hospital with regards to patients' demographics, reason for admission, diagnosis, treatment, significant events, critical incidents, and outcomes. METHODS: A retrospective observational cohort study of prospectively collected data was conducted, including all LTP emergencies admitted over a period of 2 years in the resuscitation room (RR). Variables, including indication for transfer, mode of prehospital transportation, diagnosis, and time spent in RR, were recorded. RESULTS: Of the 60,939 pediatric emergencies treated in our university hospital over 2 years, a total of 277 LTP emergencies (0.46%) were admitted in the RR. They included 160 boys and 117 girls, aged 6 days to 15.95 years (mean, 6.69 years; median, 5.06). A medical problem was identified in 55.9% (n = 155) of the children. Of the 122 children treated for a surgical problem, 35 (28.3%) went directly from the RR to the operating room. Hemodynamic instability was noted in 19.5% of all LTP emergencies, of which 1.1% benefited from O negative transfusion. Admission to the intensive care unit was necessary for 61.6% of the children transferred from another hospital. The average time spent in the RR was 46 minutes. The overall mortality rate was 7.2%. CONCLUSIONS: The LTP emergencies accounted for a small proportion of all pediatric emergencies. They were more medical than surgical cases and resuscitation measures because of hemodynamic instability were the most frequent treatment.

Single versus double retrograde intramedullary nail technique for treatment of displaced proximal humeral fractures in children: A retrospective cohort study.

Background: Highly displaced proximal humeral fractures in children with low remodeling potential need to be reduced and fixed. The use of two flexible retrograde nails became the most popular fixation technique due to the excellent functional outcome, the low complication rates, and the possibility of early mobilization. A modified single retrograde technique has been suggested by the authors to address the main disadvantage of this technique, the long operative duration. The aim of this study was to compare these techniques in terms of efficacy, and clinical and radiological outcomes. Methods: We performed a retrospective, monocentric study. Two groups of patients were defined: One was treated with the standard flexible retrograde double nail technique and the other with the modified single nail technique. The demographic and fracture characteristics were similar in both groups and the postoperative immobilization with a simple sling for 2 weeks. We compared the surgical duration for the initial fixation and hardware removal procedures. The Quick Disabilities of the Arm, Shoulder, and Hand score, the secondary displacement at 1-week follow-up, the radiological union at 6-week follow-up, and the perioperative and short-term complications were also assessed for both groups. Results: The surgical duration of the initial fixation procedure was significantly shorter in single nail technique group (p = 0.005). The percentage of excellent Quick Disabilities of the Arm, Shoulder, and Hand score (0) was similar in the two groups (p = 0.98). No secondary displacement was reported for the double nail technique group. In only one patient from the single nail technique group, we detected a secondary displacement at the first week control which did not need reoperation. In both groups, fractures were healed on the 6-week radiologic control. No cases of infection, superficial skin irritation, neurological damage, or complications related to implant removal were reported in both groups. Conclusions: The single nail technique of fixation proximal humeral fractures in children addresses the disadvantage of long surgical times, described until today, with the double nail technique without compromising the excellent functional and radiological short-term outcomes. Level of evidence: level III.

Lateral condyle fracture of the humerus in children treated with bioabsorbable materials.

The aim of this study was to compare clinical and radiological outcome of lateral condyle fracture of the elbow in children treated with bioabsorbable or metallic material. From January 2008 to December 2009, 16 children with similar fractures and ages were grouped according to the fixation material used. Children were seen at 3, 6, and 12 months and more than 4 years (mean 51.8 months) postoperatively. The clinical results were compared using the Mayo Elbow Performance Score (MEPS). Radiographic studies of the fractured and opposite elbow were assessed at last follow-up control. Twelve children had a sufficient followup and could be included in the study. Seven could be included in the traditional group and 5 in the bioabsorbable group. At 12 months, the MEPS was 100 for every child in both groups. Asymptomatic bony radiolucent visible tracks and heterotopic ossifications were noted in both groups. There were no significant differences in terms of clinical and radiological outcome between the two groups. The use of bioabsorbable pins or screws is a reasonable alternative to the traditional use of metallic materials for the treatment of lateral condyle fracture of the elbow in children.

Kingella kingae Spinal Infections in Children.

Nowadays, Kingella kingae is considered an important cause of primary spinal infections in children aged between 6 and 48 months. The presentation of the disease is often characterized by mild clinical features and a moderate biological inflammatory response, requiring a high index of suspicion. Performing magnetic resonance imaging (MRI) and obtaining an oropharyngeal specimen and subjecting it to a K. kingae-specific nucleic acid amplification test are recommended for its diagnosis. Most patients respond promptly to conservative treatment after administration of antibiotic therapy, which is prolonged for up to 3 months according to the individual clinical and biological response. Invasive surgical procedures are not required except for children who do not improve with antibiotic treatment, develop signs of cord compression, or if the presence of atypical microorganisms is suspected. Kingella kingae spinal infections usually run an indolent and benign clinical course, living no permanent sequelae.

Clinical and financial impacts of flexible intramedullary nailing in pediatric diaphyseal forearm fractures: A case-control study.

Purpose: Flexible intramedullary nailing is regularly applied for pediatric displaced unstable forearm fractures. When compared to closed reduction and casting (orthopedic treatment), flexible intramedullary nailing decreases malalignment, shortens immobilization time, and should decrease follow-up controls. Comparing flexible intramedullary nailing and orthopedic treatment in the clinical, radiological, and financial managements of these fractures was performed. Methods: Retrospective 5 years study of pediatric cases in two pediatric orthopedic university departments. Treatment method, post-operative course, and radiological follow-up were reviewed. Number of radiographs, follow-up controls, type and duration of immobilization, final bone angulation, and reported complications were compared. Extensive financial analysis was completed. Results: Of 73 girls and 168 boys included in the study, 150 were treated by flexible intramedullary nailing and 91 by orthopedic treatment. No difference was noted with regard to total number of radiographs (7.3 vs 7.2, respectively). Total number of follow-ups was 6.4 and 5.5, respectively. Malalignment occurred in two flexible intramedullary nailing and sixteen orthopedic treatments. The least expensive cost was ambulatory orthopedic treatment. Conclusion: Flexible intramedullary nailing treated children had similar numbers of radiographs or follow-up consultation, but less malunion when compared to orthopedic treatment. Orthopedic management was systematically cheaper than flexible intramedullary nailing. Unless post-operative management guidelines decreasing the number of radiographs and follow-ups are implemented, flexible intramedullary nailing will remain a costly procedure when compared to conventional orthopedic treatment. Level of evidence: level III case-control retrospective study.

Pediatric phalanx fractures: A retrospective study and review of the literature.

Purpose: Conventional radiography is frequently performed in pediatric patients in whom finger fractures are suspected. However, until now, the rate of positive findings of finger radiographic examinations in pediatric patients is unknown. This study aimed to evaluate the number of positive findings in the standard radiographic examinations of finger injuries in pediatric patients in a Level 1 trauma center systematically. Methods: We conducted a retrospective study on all children 0-16 years old admitted for acute finger injury in the Emergency Department of a University Hospital during the first semester of 2019 and received a radiographic examination. Their demographic characteristics, fracture pattern, and treatment were then analyzed and interpreted. Results: Out of 478 finger injuries reviewed in this cohort, 160 X-rays revealed positive for a fracture giving a fracture rate of 33.5%. More than half of them (51.9%) occurred in the age group of adolescents (11-16 years). Among all finger fractures, only 3.8% of them treated surgically. Conclusion: In this study, a relevant amount of standard finger radiographs revealed a low fracture rate and a rare operative indication of 3.8%. Therefore, indications for X-rays should be reviewed properly and alternative procedures should be discussed. Clinical decision rules should be developed and the necessary pathways must be implemented to minimize radiation exposure, waiting time, and costs.Level of evidence: level IV.

Pilot Study and Preliminary Results of Biodegradable Intramedullary Nailing of Forearm Fractures in Children.

(1) Background: Diaphyseal forearm fractures are a common injury in children and adolescents. When operative treatment is needed, elastic stable intramedullary nailing (ESIN) is the most common surgical procedure. Although there is no clear evidence, hardware removal after fracture healing is performed in many patients. Often, the primary minimal invasive incision needs to be widened during implant removal. In order to decrease the burden of care of pediatric fractures, significant efforts were made to develop biodegradable implants, which make hardware removal unnecessary. Our study will conduct an observational trial on the clinical use of the Activa IM-Nail™ in forearm fractures in children between 3 and 13 years of age. The objective of this trial is to evaluate the risks and benefits of the Activa IM-Nail™. Among other objectives, the rate of refracture will be determined. (2) Methods: An international Europe-based, multicenter, prospective, single-arm, open-label study will be performed to ascertain the rate of refracture and to determine the subjective benefits of Activa IM-Nail™ for patients, parents and other caregivers. The study will include clinical follow-up including early post-operative complication, radiographs until bony healing and an additional follow-up after 1 year. At this stage, preliminary results and early complications on 76 patients are analyzed in this study and presented. (3) Results: As of April 2022, 76 patients were enrolled as per study protocol. There were 31 girls (40.8%) and 45 boys (59.2%). The mean age at the time of inclusion was 8.9 years (±2.4 years). The mean operation time was 58.9 ± 22.9 min (range, 15-119 min). The mean follow-up time was 8.9 ± 5.1 months (range, 0.2-18.6). Up to now, one refracture has occurred in one child falling from a height of about one meter 7 months after index surgery (1/76; 1.3%). (4) Conclusion: The research project assesses the safety and effectiveness of Activa IM-Nails™ as part of the surgical treatment of dislocated forearm fractures in children in the context of a PMCF study. The use of Activa IM-Nails™ with regard to various objectives, including postoperative complications and refracture rate, seems to be equal to the standard titan ESIN procedure compared to the literature. Preliminary results are encouraging and are made available.

Diagnostic algorithm for a validated displacement grading of pediatric supracondylar fractures.

BACKGROUND: The first AO comprehensive pediatric long bone fracture classification system has been established following a structured path of development and validation with experienced pediatric surgeons. METHODS: A follow-up series of agreement studies was applied to specify and evaluate a grading system for displacement of pediatric supracondylar fractures. An iterative process comprising an international group of 5 experienced pediatric surgeons (Phase 1) followed by a pragmatic multicenter agreement study involving 26 raters (Phase 2) was used. The last evaluations were conducted on a consecutive collection of 154 supracondylar fractures documented by standard anteroposterior and lateral radiographs. RESULTS: Fractures were classified according to 1 of 4 grades: I=incomplete fracture with no or minimal displacement; II=Incomplete fracture with continuity of the posterior (extension fracture) or anterior cortex (flexion fracture); III=lack of bone continuity (broken cortex), but still some contact between the fracture planes; IV=complete fracture with no bone continuity (broken cortex), and no contact between the fracture planes. A diagnostic algorithm to support the practical application of the grading system in a clinical setting, as well as an aid using a circle placed over the capitellum was proposed. The overall κ coefficients were 0.68 and 0.61 in the Phase 1 and Phase 2 studies, respectively. In the Phase 1 study, fracture grades I, II, III, and IV were classified with median accuracies of 91%, 82%, 83%, and 99.5%, respectively. Similar median accuracies of 86% (Grade I), 73% (Grade II), 83% (Grade III), and 92% were reported for the Phase 2 study. Reliability was high in distinguishing complete, unstable fractures from stable injuries [ie, κ coefficients of 0.84 (Phase 1) and 0.83 (Phase 2) were calculated]; in Phase 2, surgeons' accuracies in classifying complete fractures were all above 85%. CONCLUSIONS: With clear and unambiguous definition, this new grading system for supracondylar fracture displacement has proved to be sufficiently reliable and accurate when applied by pediatric surgeons in the framework of clinical routine as well as research. LEVEL OF EVIDENCE: Diagnostic study, Level II.

Occipital sleep spindles predict sequence learning in a visuo-motor task.

STUDY OBJECTIVES: The brain appears to use internal models to successfully interact with its environment via active predictions of future events. Both internal models and the predictions derived from them are based on previous experience. However, it remains unclear how previously encoded information is maintained to support this function, especially in the visual domain. In the present study, we hypothesized that sleep consolidates newly encoded spatio-temporal regularities to improve predictions afterwards. METHODS: We tested this hypothesis using a novel sequence-learning paradigm that aimed to dissociate perceptual from motor learning. We recorded behavioral performance and high-density electroencephalography (EEG) in male human participants during initial training and during testing two days later, following an experimental night of sleep (n = 16, including high-density EEG recordings) or wakefulness (n = 17). RESULTS: Our results show sleep-dependent behavioral improvements correlated with sleep-spindle activity specifically over occipital cortices. Moreover, event-related potential (ERP) responses indicate a shift of attention away from predictable to unpredictable sequences after sleep, consistent with enhanced automaticity in the processing of predictable sequences. CONCLUSIONS: These findings suggest a sleep-dependent improvement in the prediction of visual sequences, likely related to visual cortex reactivation during sleep spindles. Considering that controls in our experiments did not fully exclude oculomotor contributions, future studies will need to address the extent to which these effects depend on purely perceptual versus oculomotor sequence learning.