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Introduction: The purpose of this study was to perform a systematic review and meta-analysis of the effects of training simulators on surgical skill measures across randomized controlled trials. The authors hypothesized that simulated training would (1) result in objective improvements in skill acquisition and (2) be heterogeneous regarding the outcomes and types of validity assessed. Methods: The Cochrane Database of Systematic Reviews, the Central Register of Controlled Trials, PubMed, EMBASE, and MEDLINE databases were queried for Level I studies on training simulators between 2007 and 2019 in accordance with the 2009 Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Exclusion criteria were studies without discrete assessment of skills acquisition after surgical simulator training and level of evidence II to V. The Jadad scale was used to assess the methodological quality of all included articles. Data pertaining to patient demographics, validity measures, simulator types, and study-specific outcome measures were extracted. Meta-analyses adjusted for random effects and heterogeneity analyses (I2) were used to compare pooled time-to-completion and performance outcomes among included studies. Results: A total of 24 studies with 494 participants were identified. The most common simulator type involved knee arthroscopy (11 studies, 45.8%). Eight studies reporting time-to-task completion and performance scores were included in the meta-analysis. Virtual reality training was favored in time-to-task completion (mean difference = −82.25 seconds, P = 0.002) and improvement in objective performance scores (mean difference = 1.24, P = 0.02) relative to traditional training. Sensitivity analysis of time-to-task completion based on the length of training interval revealed a mean difference of −45.24 (P = 0.07) and −137.74 (P < 0.001) seconds for the short-term and immediate posttesting subgroups, respectively. Conclusion: Overall, improved task efficiency and performance were observed with the use of orthopaedic simulators. However, simulator type, training protocols, and outcome measures were heterogeneous. Future studies are warranted to evaluate financial cost and longitudinal training programs and to standardize outcomes regarding the use of simulators in orthopaedic education. Level of Evidence: Level I

We show here that computer game players can build high-quality crystal structures. Introduction of a new feature into the computer game Foldit allows players to build and real-space refine structures into electron density maps. To assess the usefulness of this feature, we held a crystallographic model-building competition between trained crystallographers, undergraduate students, Foldit players and automatic model-building algorithms. After removal of disordered residues, a team of Foldit players achieved the most accurate structure. Analysing the target protein of the competition, YPL067C, uncovered a new family of histidine triad proteins apparently involved in the prevention of amyloid toxicity. From this study, we conclude that crystallographers can utilize crowdsourcing to interpret electron density information and to produce structure solutions of the highest quality.

Background: Medial meniscus posterior root (MMPR) injuries accelerate the progression of osteoarthritis. While partial meniscectomy was once considered the gold standard for treatment, meniscus root repair has become increasingly utilized with reported improvements in clinical and biomechanical outcomes. Purpose: To perform a systematic review of biomechanical outcomes and a meta–analysis of clinical and radiographic outcomes after MMPR repair. Study Design: Meta-analysis and systematic review; Level of evidence, 4. Methods: The PubMed, Embase, and Cochrane databases were queried in August 2021 for studies reporting biomechanical, clinical, and radiographic outcomes after MMPR repair. Biomechanical studies were assessed for main results and conclusions. Data including study characteristics, cohort demographics, and outcomes were extracted. Included clinical studies were analyzed with a random–effects meta-analysis of proportions for binary outcomes or continuous outcomes for mean differences between preoperative and postoperative time points. Subgroup analysis for studies reporting repair outcomes with concomitant high tibial osteotomy (HTO) was performed where appropriate. Results: A total of 13 biomechanical studies were identified and reported an overall improvement in mean and peak contact pressures after MMPR repair. There were 24 clinical studies, consisting of 876 patients (877 knees), identified, with 3 studies (106 knees) reporting outcomes with concomitant HTO. The mean patient age was 57.1 years (range, 23-74 years), with a mean follow–up of 27.7 months (range, 2-64 months). Overall, clinical outcomes (Lysholm, Hospital for Special Surgery, International Knee Documentation Committee, visual analog scale for pain, Tegner, and Knee injury and Osteoarthritis Outcome Score scores) were noted to improve postoperatively compared with preoperatively, with improved Lysholm scores in patients undergoing concomitant HTO versus MMPR repair alone. Meniscal extrusion was not significantly improved after MMPR repair compared with preoperative measurements. The progression in Kellgren-Lawrence grades from grade 0 to grades 1 to 3 occurred in 5.9% (21/354) of patients after repair, with no patients progressing from grades 1 to 3 to grade 4. Conclusion: MMPR repair generally improved biomechanical outcomes and led to improved patient–reported outcomes with greater improvements noted in patients undergoing concomitant HTO. Repair did not significantly improve meniscal extrusion, while only 5.9% of patients were noted to progress to low–grade osteoarthritis. The high level of heterogeneity in the included biomechanical and clinical investigations emphasizes the need for more well–designed studies that evaluate outcomes after MMPR repair.

Infants with a history of prematurity and bronchopulmonary dysplasia (BPD) have a high risk of asthma and viral-induced exacerbations later in life. We hypothesized that hyperoxic exposure, a predisposing factor to BPD, modulates the innate immune response, producing an exaggerated pro-inflammatory reaction to viral infection. Two-to-3 day-old C57BL/6J mice were exposed to air or 75% oxygen for 14 days. Mice were infected intranasally with rhinovirus (RV) immediately after O2 exposure. Lung mRNA and protein expression, histology, dendritic cells (DCs) and airways responsiveness were assessed 1-12 days after infection. Tracheal aspirates from premature human infants were collected for mRNA detection. Hyperoxia increased lung IL-12 expression which persisted up to 12 days post-exposure. Hyperoxia-exposed RV-infected mice showed further increases in IL-12 and increased expression of IFN-γ, TNF-α, CCL2, CCL3 and CCL4, as well as increased airway inflammation and responsiveness. In RV-infected, air-exposed mice the response was not significant. Induced IL-12 expression in hyperoxia-exposed, RV-infected mice was associated with increased IL-12-producing CD103+ lung DCs. Hyperoxia also increased expression of Clec9a, a CD103+ DC-specific damaged cell-recognition molecule. Hyperoxia increased levels of ATP metabolites and expression of adenosine receptor A1, further evidence of cell damage and related signaling. In human preterm infants, tracheal aspirate Clec9a expression positively correlated with the level of prematurity. Hyperoxic exposure increases the activation of CD103+, Clec9a+ DCs, leading to increased inflammation and airway hyperresponsiveness upon RV infection. In premature infants, danger signal-induced DC activation may promote pro-inflammatory airway responses, thereby increasing respiratory morbidity.

Background: Anterior cruciate ligament reconstruction (ACLR) is associated with moderate to severe pain in the immediate postoperative period. The optimal individual preemptive or intraoperative anesthetic modality on postoperative pain control is not well-known. Purpose: To systematically review and perform a meta-analysis comparing postoperative pain scores (visual analog scale [VAS]), opioid consumption, and incidence of complications during the first 24 hours after primary ACLR in patients receiving spinal anesthetic, adjunct regional nerve blocks, or local analgesics. Study Design: Systematic review and meta-analysis. Methods: PubMed, Embase, MEDLINE, Biosis Previews, SPORTDiscus, Ovid, PEDRO, and the Cochrane Library databases were systematically searched from inception to March 2020 for human studies, using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist. Inclusion criteria consisted of (1) level 1 studies reporting on the use of spinal anesthesia, adjunct regional anesthesia (femoral nerve block [FNB] or adductor canal block [ACB]), or local analgesia in patients undergoing primary ACLR and (2) studies reporting on patient-reported VAS, opioid consumption, and incidence of complications related to anesthesia within the first 24 hours after surgery. Non–level 1 studies, studies utilizing a combination of anesthetic modalities, and those not reporting outcomes during the first 24 hours were excluded. Data were synthesized, and a random effects meta-analysis was performed to determine postoperative pain, opioid use, and complications based on anesthetic modality at multiple time points (0-4, 4-8, 8-12, 12-24 hours). Results: A total of 263 studies were screened, of which 27 level 1 studies (n = 16 regional blocks; n = 12 local; n = 4 spinal) met the inclusion criteria and were included in the meta-analysis. VAS scores were significantly lower in patients receiving a regional block as compared with spinal anesthesia 8 to 12 hours after surgery ( P < .01), patients receiving an FNB versus ACB at 12 to 24 hours ( P < .01), and those treated with a continuous FNB rather than single-shot regional blocks (FNB, ACB) at 12 to 24 hours ( P < .01). No significant difference in VAS was appreciated when spinal, regional, and local anesthesia groups were compared. Conclusion: Based on evidence from level 1 studies, pain control after primary ACLR based on VAS was significantly improved at 8 to 12 hours in patients receiving regional anesthesia as compared with spinal anesthesia. Pain scores were significantly lower at 12 to 24 hours in patients receiving FNB versus ACB and those treated with continuous FNB rather than single-shot regional anesthetic.

Purpose The management of posterolateral corner (PLC) injuries has significantly evolved over the past 2 decades. The purpose of this study was to determine the current worldview of key concepts on the diagnosis, treatment strategy, and rehabilitation for patients presenting with PLC injuries. Methods A 12-question multiple-choice online survey was designed to address key questions in the diagnosis, treatment, and rehabilitation of PLC injuries. The survey was distributed to the most important international sports medicine societies worldwide. Clinical agreement was defined as > 80% of agreement in responses and general agreement was defined as > 60% of agreement in responses. Results 975 surgeons completed the survey with 49% from Europe, 21% from North America, 12% from Latin America, 12% from Asia, and smaller percentages from Africa and Oceania. Less than 14% of respondents manage more than ten PCL injuries yearly. Clinical agreement of > 80% was only evident in the use of MRI in the diagnosis of PLC injury. Responses for surgical treatment were split between isometric fibular-based reconstruction techniques and anatomically based fibular and tibial-based reconstructions. A general agreement of > 60% was present for the use of a post-operative brace in the early rehabilitation. ConclusionIn the global surgical community, there remains a significant variability in the diagnosis, treatment, and postoperative management of PLC injuries. The number of PLC injuries treated yearly by most surgeons remains low. As global clinical consensus for PLC remains elusive, societies will need to play an important role in the dissemination of evidencebased practices for PLC injuries. Level of evidence IV.

Background: Posterolateral corner (PLC) injuries of the knee are being increasingly recognized and treated in current orthopaedic practice. While there are numerous systematic reviews evaluating the management and outcomes after PLC injuries, there are limited data investigating complications after PLC reconstruction or repair. Purpose: To systematically review the literature to determine the incidence of postoperative complications after the surgical treatment of PLC injury. Study Design: Systematic review; Level of evidence, 4. Methods: The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), Embase (2008-2019), and MEDLINE (2008-2019) were queried for literature reporting on PLC reconstruction or repair, with or without concomitant ligamentous or meniscal surgery. Data including type of surgery performed, concomitant procedures, and follow-up time were extracted. Complications recorded included intra- and postoperative complications. Results: After the intra- and postoperative complication data of 60 studies (1747 cases) were combined, surgical management of PLC injuries was associated with an intraoperative complication rate of 0.34% (range, 0%-2.8%) and a postoperative complication rate of 20% (range, 0%-51.2%). The most common postoperative complication was arthrofibrosis (range, 0%-20%). The overall infection rate was 1.3% (range, 0%-10%). Four cases of postoperative common peroneal nerve palsy were reported. Failure of reconstruction or repair was reported in 164 (9.4%) of all cases examined (range, 0%-37.1%). Conclusion: Although the intraoperative rate of complications during PLC reconstructions is low, postoperative complications rates of 20% can be expected, including arthrofibrosis, infection, and neurovascular injury. PLC structures repaired or reconstructed failed in 9.4% of the cases.