The reproducibility of published research has become an important topic in science policy. A number of large-scale replication projects have been conducted to gauge the overall reproducibility in ...specific academic fields. Here, we present an analysis of data from four studies which sought to forecast the outcomes of replication projects in the social and behavioural sciences, using human experts who participated in prediction markets and answered surveys. Because the number of findings replicated and predicted in each individual study was small, pooling the data offers an opportunity to evaluate hypotheses regarding the performance of prediction markets and surveys at a higher power. In total, peer beliefs were elicited for the replication outcomes of 103 published findings. We find there is information within the scientific community about the replicability of scientific findings, and that both surveys and prediction markets can be used to elicit and aggregate this information. Our results show prediction markets can determine the outcomes of direct replications with 73% accuracy (n = 103). Both the prediction market prices, and the average survey responses are correlated with outcomes (0.581 and 0.564 respectively, both p < .001). We also found a significant relationship between p-values of the original findings and replication outcomes. The dataset is made available through the R package "pooledmaRket" and can be used to further study community beliefs towards replications outcomes as elicited in the surveys and prediction markets.
Purpose
(1) To compare the incidence of post-operative septic arthritis following anterior cruciate ligament reconstruction (ACLR) between patients receiving routine pre-operative intravenous (IV) ...prophylaxis only intravenous (IV) infection prophylaxis and patients receiving additional graft-soaking in a vancomycin solution (5 mg/ml) perioperatively. (2) To review the literature regarding effects of graft-soaking in vancomycin solutions on outcomes, complication rates and tendon properties in ACLR.
Methods
To identify studies pertaining to routine pre-operative IV prophylaxis and additional usage of intra-operative vancomycin-soaked grafts in primary ACLR, the Cochrane Library, SCOPUS and MEDLINE were searched till June 2018 for English and German language studies of all levels of evidence following the PRISMA guidelines. Additionally, all accepted abstracts at the ESSKA 2018, ISAKOS 2017, AGA 2017 and AOSSM 2017 meetings were screened. Data regarding the incidence of septic arthritis were abstracted and combined in a meta-analysis. Data including outcome scores, complication rates and in vitro analyses of tendon properties were collected and summarized descriptively.
Results
Upon screening 785 titles, 8 studies were included. These studies examined 5,075 patients following ACLR and followed from 6 to 52 weeks post-operatively. Of those 2099 patients in the routine pre-operative IV prophylaxis group, 44 (2.1%) cases of early septic arthritis were reported. In contrast, there were no reports of septic arthritis following ACLR in 2976 cases of vancomycin-soaked grafts. The meta-analysis yielded an odds ratio of 0.04 (0.01–0.16) favouring the addition of intra-operative vancomycin-soaking of grafts. Across all available studies, no differences in clinical outcome (i.e. incidence of ACL revision, IKDC score, Tegner score), biomechanical tendon properties, or cartilage integrity between patients with and without vancomycin-soaked grafts were identified.
Conclusion
The incidence of septic arthritis following ACLR can be reduced dramatically by vancomycin-soaking the grafts intra-operatively prior to graft passage and fixation. Within the limitation confines of this study, intra-operative graft-soaking in vancomycin appears to be a safe and effective method to reduce the incidence of septic arthritis following ACLR. Still, it remains debatable if the available data facilitate the recommendation for a universal application of vancomycin-soaking for all ACLR patients or if it should be reserved for patients at risk, including the use hamstring tendons, revision cases and in the presence of medical preconditions.
Level of evidence
Level IV, systematic review of Level III and Level IV studies.
Behandlung der akuten Knieluxation Pfeiffer, Thomas R; Günther Daniel PD Dr med
Der Unfallchirurg,
01/2024, Volume:
127, Issue:
1
Journal Article
Peer reviewed
ZusammenfassungEine Knieluxation ist eine schwerwiegende Verletzung, bei der mindestens 2 der 4 ligamentären Hauptstabilisatoren des Kniegelenks betroffen sind. Diese Verletzung führt zu einer ...multidirektionalen Instabilität. Im Rahmen der Luxationen des Kniegelenks können auch die A. poplitea und der N. peroneus geschädigt werden. Bei Luxationen mit Gefäßbeteiligung handelt es sich um eine potenziell extremitätenbedrohende Verletzung. Die Diagnosestellung der Knieluxation kann aufgrund einer hohen Rate spontaner Repositionen bei der Erstuntersuchung erschwert sein. Knieluxationen sind selten und treten hauptsächlich bei jungen Männern auf. Sie werden oft durch hochenergetische Traumata verursacht, können jedoch auch durch niedrigenergetische Verletzungen bedingt sein. Adipositas erhöht das Risiko für Knieluxationen. Die Klassifikation einer Knieluxation basiert auf den beteiligten anatomischen Strukturen und der Luxationsrichtung. Die akute Behandlung umfasst Reposition und stabilisierende Maßnahmen. Begleitverletzungen wie Gefäß‑, Nerven‑, Streckapparat- und osteochondrale Verletzungen sowie Frakturen und Meniskusverletzungen beeinflussen das therapeutische Vorgehen und das Behandlungsergebnis. Die definitive operative Therapie hängt von der Schwere der Verletzung ab und kann eine ligamentäre Rekonstruktion oder Naht mit „bracing“ beinhalten. Die Nachbehandlung sollte individuell angepasst werden und zielt auf die Wiederherstellung einer stabilen und funktionsfähigen Kniegelenkfunktion ab. Komplikationen wie Arthrofibrose, N.-peroneus-Parese, Kompartmentsyndrom, postoperative Infektion und Rezidivinstabilitäten können auftreten. Langfristig besteht ein erhöhtes Risiko für die Entwicklung einer symptomatischen Arthrose.
A knee dislocation is a serious injury involving at least two of the four major ligamentous stabilizers of the knee. This injury results in multidirectional knee instability. In dislocation of the ...knee the popliteal artery and the peroneal nerve can also be damaged. Dislocations with vascular involvement are potentially threatening injuries of the lower extremities. The diagnosis of knee dislocation can be difficult due to a high rate of spontaneous reduction at the initial examination. Knee dislocations are rare and mainly occur in young men. They are mostly caused by high-energy trauma; however, they can also be caused by low-energy injuries. Obesity increases the risk of knee dislocations. The classification of a knee dislocation is based on the anatomical structures involved and the direction of dislocation. The acute treatment includes reduction and stabilization measures. Associated injuries, such as vascular, nerve, extensor mechanism and cartilage injuries as well as fractures and meniscal injuries can influence the treatment approach and the outcome. The definitive surgical treatment depends on the severity of the injury and can include ligament reconstruction or repair with bracing. The aftercare should be individually adapted with the aim to restore knee joint stability and function. Complications such as arthrofibrosis, peroneal nerve palsy, compartment syndrome, postoperative infection and recurrent instability can occur. In the long term, patients have an increased risk for the development of symptomatic osteoarthritis.
The purpose of this study was to examine the relationship between distal femoral morphology and anterior cruciate ligament (ACL) injury, ACL reconstruction (ACLR) failure, and contralateral ACL ...injury. It was hypothesized that increased posterior femoral condylar depth, quantified as the lateral femoral condyle ratio, would correlate with increased risk of primary ACL injuries, ACLR failures, and contralateral ACL injuries.
The charts of consecutive patients who underwent arthroscopic knee surgery at an academic medical center from 2012 to 2016 with minimum follow-up of 24 months were retrospectively reviewed. Patients were stratified into 4 groups: (1) a control group of patients with no ACL injury, (2) patients with primary ACL injury, (3) patients with failed ACLR, and (4) patients with previous ACL injury and subsequent contralateral ACL injury. With use of lateral radiographs, the ratio of posterior femoral condylar depth to total condylar length was defined as the lateral femoral condyle ratio. Differences between study groups were identified with use of analysis-of-variance (ANOVA) and post-hoc testing with significance set at p < 0.05. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cutoff for detecting increased risk of ACL injury.
Two hundred patients met the inclusion criteria. The mean lateral femoral condyle ratios (and standard deviations) were 61.2% ± 2.4% in the control group, 64.2% ± 3.8% in the primary ACL injury group, 64.4% ± 3.6% in the failed ACLR group, and 66.9% ± 4.3% in the contralateral ACL injury group. Patients who had a primary ACL injury, failed ACLR, or contralateral ACL injury had significantly higher ratios compared with the control group (p < 0.008). ROC curve analysis demonstrated that a lateral femoral condyle ratio of >63% was associated with an increased risk for ACL injury, with a sensitivity of 77% and a specificity of 72%.
The data from this study show that increased posterior femoral condylar depth, quantified as the lateral femoral condyle ratio, is associated with an increased risk of ACL injury, including primary and contralateral ACL injuries. The data from this study may help clinicians to identify patients at a greater risk of ACL injury.
Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Rewiring neural circuits by the formation and elimination of synapses is thought to be a key cellular mechanism of learning and memory in the mammalian brain. Dendritic spines are the postsynaptic ...structural component of excitatory synapses, and their experience-dependent plasticity has been extensively studied in mouse superficial cortex using two-photon microscopy in vivo. By contrast, very little is known about spine plasticity in the hippocampus, which is the archetypical memory center of the brain, mostly because it is difficult to visualize dendritic spines in this deeply embedded structure with sufficient spatial resolution. We developed chronic 2P-STED microscopy in mouse hippocampus, using a 'hippocampal window' based on resection of cortical tissue and a long working distance objective for optical access. We observed a two-fold higher spine density than previous studies and measured a spine turnover of ~40% within 4 days, which depended on spine size. We thus provide direct evidence for a high level of structural rewiring of synaptic circuits and new insights into the structure-dynamics relationship of hippocampal spines. Having established chronic super-resolution microscopy in the hippocampus in vivo, our study enables longitudinal and correlative analyses of nanoscale neuroanatomical structures with genetic, molecular and behavioral experiments.
Abstract
Astrocytic Ca
2+
signals can be fast and local, supporting the idea that astrocytes have the ability to regulate single synapses. However, the anatomical basis of such specific signaling ...remains unclear, owing to difficulties in resolving the spongiform domain of astrocytes where most tripartite synapses are located. Using 3D-STED microscopy in living organotypic brain slices, we imaged the spongiform domain of astrocytes and observed a reticular meshwork of nodes and shafts that often formed loop-like structures. These anatomical features were also observed in acute hippocampal slices and in barrel cortex in vivo. The majority of dendritic spines were contacted by nodes and their sizes were correlated. FRAP experiments and Ca
2+
imaging showed that nodes were biochemical compartments and Ca
2+
microdomains. Mapping astrocytic Ca
2+
signals onto STED images of nodes and dendritic spines showed they were associated with individual synapses. Here, we report on the nanoscale organization of astrocytes, identifying nodes as a functional astrocytic component of tripartite synapses that may enable synapse-specific communication between neurons and astrocytes.
Purpose
Distal femur morphology has been shown to influence knee joint kinematics and may affect rotatory knee laxity. The purpose of this study was to determine the relationship between rotatory ...knee laxity and distal femoral morphology in patients with complete anterior cruciate ligament (ACL) rupture. It was hypothesized that increased posterior femoral condylar depth on standard lateral radiographs, quantified as the “lateral femoral condyle ratio” would correlate with increased rotatory knee laxity, measured by a quantitative pivot shift test.
Methods
Consecutive patients who underwent ACL reconstruction from 2014 to 2016 were retrospectively reviewed. A standardized pivot shift test was performed preoperatively on both knees and quantified using tablet technology. Using standard lateral radiographs of the knee, the ratio of posterior condylar distance over total condylar distance was defined as the lateral femoral condyle ratio.
Results
Data sets were obtained for 57 patients. The mean anterior translation of the lateral knee compartment during a quantitative pivot shift test was found to be 4.0 ± 2.4 mm and 1.3 ± 0.9 mm for the injured and uninjured knees, respectively. The mean lateral femoral condyle ratio on X-ray was 63.2 ± 4.5%. There were significant correlations between the lateral femoral condyle ratio and the absolute quantitative (
ρ
= 0.370,
p
< 0.05) and side-to-side differences in anterior translation of the lateral knee compartment (
ρ
= 0.419,
p
< 0.05).
Conclusion
The most important finding from this study is that increased posterior femoral condylar depth, quantified as a lateral femoral condyle ratio, is associated with increased rotatory knee laxity in ACL-deficient patients. This suggests that distal femur morphology may influence rotatory knee laxity. This study may assist clinicians in evaluating ACL injuries and identifying patients at greater risk for persistent increased rotatory knee laxity after ACL reconstruction.
Level of evidence
III.
Background:
Studies have revealed that vancomycin soaking of the anterior cruciate ligament (ACL) graft can drastically reduce the incidence of postoperative infections after ACL reconstruction. ...However, it remains unknown whether the chondrotoxic threshold of vancomycin in synovial fluid is exceeded during this process. Several studies investigated the chondrotoxic properties of vancomycin in in vitro experiments and described a concentration of 1000 µg/mL as the critical threshold.
Purpose/Hypothesis:
The purpose of the study was to measure the vancomycin concentration in synovial fluid after ACL reconstruction with vancomycin-soaked autografts. It was hypothesized that intra-articular vancomycin concentrations in the synovial fluid would not reach the chondrotoxic threshold of 1000 µg/mL after vancomycin soaking of autologous semitendinosus tendon and soft tissue quadriceps tendon grafts for ACL reconstruction.
Study Design:
Cohort study; Level of evidence, 3.
Methods:
The study enrolled 10 patients undergoing ACL reconstruction using 4-strand semitendinosus tendon autografts and 10 patients undergoing ACL reconstruction using soft tissue quadriceps tendon autografts. Before implantation, each harvested graft was intraoperatively wrapped in gauze swabs that had been soaked in a 5-mg/mL vancomycin solution. After wound closure, an aspirate of 5 mL of synovial fluid was taken from each patient. The vancomycin concentration of the aspirate was analyzed using high-performance liquid chromatography–tandem mass spectrometry. Spearman rho correlation coefficients were used to identify relationships between the parameters, and the t test was used to test for differences between graft types. A P value of <.05 was considered statistically significant.
Results:
The study included 20 patients (14 women and 6 men; age, 29.35 ± 11.3 years). The mean vancomycin concentration measured in the synovial fluid was 23.23 ± 21.68 µg/mL, with a minimum concentration of 2.32 µg/mL and a maximum concentration of 71.56 µg/mL. No significant difference was found between the 2 graft types (P = .911). Significant positive correlation (r = 0.644; P < .05) was observed only between the vancomycin concentration and the mean duration from initiation of vancomycin soaking of semitendinosus tendon grafts to implantation (13.4 ± 6 minutes). No correlations were observed between the vancomycin concentration and the duration from implantation to fluid aspiration or between the vancomycin concentration and the graft diameter (median, 8.5 mm; range, 6.0-10.0 mm) for both graft types.
Conclusion:
Chondrotoxic vancomycin concentrations ≥1000 µg/mL were not reached in any aspiration of synovial fluid after ACL reconstruction using soft tissue autografts that were intraoperatively soaked in a 5-mg/mL vancomycin solution. Against the backdrop of multiple studies that showed significantly reduced infection rates after ACL reconstruction when vancomycin soaking was used, this study suggests that the chondrotoxic properties of this method are negligible because of its submarginal intra-articular concentrations.
•Psychologists participated in prediction markets to predict replication outcomes.•Prediction markets correctly predicted 75% of the replication outcomes.•Prediction markets performed better than ...survey data in predicting replication outcomes.•Survey data performed better in predicting relative effect size of the replications.
Understanding and improving reproducibility is crucial for scientific progress. Prediction markets and related methods of eliciting peer beliefs are promising tools to predict replication outcomes. We invited researchers in the field of psychology to judge the replicability of 24 studies replicated in the large scale Many Labs 2 project. We elicited peer beliefs in prediction markets and surveys about two replication success metrics: the probability that the replication yields a statistically significant effect in the original direction (p < 0.001), and the relative effect size of the replication. The prediction markets correctly predicted 75% of the replication outcomes, and were highly correlated with the replication outcomes. Survey beliefs were also significantly correlated with replication outcomes, but had larger prediction errors. The prediction markets for relative effect sizes attracted little trading and thus did not work well. The survey beliefs about relative effect sizes performed better and were significantly correlated with observed relative effect sizes. The results suggest that replication outcomes can be predicted and that the elicitation of peer beliefs can increase our knowledge about scientific reproducibility and the dynamics of hypothesis testing.
PDF
