Adherence to Wide-Abduction Brace Treatment is Associated With Improved Hip Abduction and Radiographic Outcomes in Legg-Calvé-Perthes Disease.

INTRODUCTION: The wide-abduction A-frame brace contains the femoral head to improve its remodeling in Legg-Calvé-Perthes disease (LCPD). There is no study of the effect of brace adherence on hip outcomes. The purpose of this study was to determine if patient adherence to A-frame brace treatment is associated with improved hip abduction range of motion and radiographic outcomes in children with LCPD. METHODS: This retrospective study included patients aged 4 to 11 years with LCPD treated with an A-frame brace. Patients aged >11 and those treated with osteotomy before completing brace treatment were excluded. Built-in temperature sensors measured brace wear. Hip abduction was measured on examination before and after bracing. Deformity index (DI) and sphericity deviation score (SDS) were measured from radiographs at the 2-year follow-up and healed stage, respectively. Pearson correlation and multiple regression analyses were performed. RESULTS: Fifty-seven patients (44 male; 77%) were included with a mean age of 7.0±1.6 at brace treatment and mean adherence of 0.66±0.28. Brace adherence was associated with increased hip abduction ( R =0.36; P =0.006) and decreased DI ( R =-0.37; P =0.042) across all patients, and decreased SDS in patients <9 years old at the time of brace treatment ( R =-0.58; P =0.024). A +0.50 increase in adherence was associated with +9.4° hip abduction ( P =0.018), -0.13 DI ( P =0.027), and -17.7 SDS ( P =0.019). CONCLUSIONS: Adherence to A-frame brace treatment was associated with increased hip abduction, decreased femoral head deformity, and increased sphericity. Patients and parents can be counseled regarding brace adherence to maximize outcomes of treatment. LEVEL OF EVIDENCE: III-Therapeutic Study.

Evaluating the Clinical Utility of Brachial Plexus Block for Reducing Opioid Exposure in Pediatric Elbow Fracture Surgery: A Retrospective Cohort Study.

Background and Objectives: Reducing opioid exposure in common pediatric surgeries is of paramount importance. This study aimed to assess the efficacy of regional nerve blocks in reducing opioid exposure while preserving high success rates. Materials and Methods: We conducted a retrospective matched cohort study (1:1) including patients with elbow fractures < 12 years old who underwent treatment with percutaneous pinning. Patients were divided into general-anesthesia (GA) and GA-followed-by-supraclavicular-brachial-plexus-block (GA-SCB) groups. The primary outcome was the number of patients administered postoperative rescue opioids. The secondary outcomes included intraoperative and postoperative opioid administration, the time to first request for rescue analgesia, pain scores, block success rate, block performing time, and block-related complications. Results: In a total of 478 patients, 363 underwent percutaneous pinning, and 86 were cohort-matched (GA: n = 43, GA-SCB: n = 43). On the first postoperative day, 34 (79.0%) patients in the GA group were administered postoperative rescue opioids, compared with 12 (27.9%) in the GA-SCB group (p < 0.001). All the patients in the GA-SCB group were opioid-free during the intraoperative period. No SCB-associated complications were observed. Total opioid consumption was significantly lower in the GA-SCB group than in the GA group until the first postoperative day (GA vs. GA-SCB, 3.2 ± 3.0 mg vs. 0.9 ± 1.8 mg, p < 0.001). Conclusions: SCB application in pediatric patients who underwent elbow fracture surgery significantly reduced opioid exposure and had a high success rate when performed using ultrasound guidance by an expert. Furthermore, the complication risk and surgical delay were minimal.

The Difference in Tibial Tuberosity to Trochlear Groove Distance Between CT and MRI Arises From the Degree of Knee Flexion During Imaging.

BACKGROUND: Tibial tuberosity to trochlear groove distance (TT-TG) has been reported to have different values according to imaging modalities, usually higher in computed tomography (CT) than in magnetic resonance imaging (MRI). This difference is thought to be caused by the degree of knee flexion during imaging, but few studies have aimed to elucidate the cause. METHODS: Five hundred eight patients with knee CT or MRI performed between ages of 6 to 16 years without underlying diseases affecting the musculoskeletal system were included. This study was conducted in 2 statistical ways. (1) Propensity score matching was performed for the imaging modality, and the bony TT-TG was compared between the 2 matched groups. (2) A regression model was fitted with 484 patients with either CT or MRI (a training set), and validation of the fitted model was performed with 24 patients with both CT and MRI simultaneously taken within a week (a test set). The predicted TT-TG values were compared with the measured values. RESULTS: (1) Eighty-one patients were successfully matched by propensity score (all the standardized mean differences < 0.1) for each modality. In the matched patients, there was no significant difference in TT-TG according to the imaging modality (11.3 ± 3.7 mm for CT, 10.4 ± 3.8 mm for MRI, P = 0.126). (2) For the model fitting, different linear models were fitted before and after 10 degrees of knee flexion angle because there was a sharp change in TT-TG when the knee flexion angle was <10 degrees. The predicted TT-TG values did not significantly differ from the measured values (10.2 ± 4.3 mm vs. 9.0 ± 5.1 mm, P = 0.124). CONCLUSIONS: This study is the first to statistically prove that the difference between TT-TG in MRI and CT originates from the different degrees of knee flexion. In addition, although more studies are needed, authors recommend imaging to be performed with the knee flexed at least 10 degrees for more reliable measurements because TT-TG changes sharply if the knee flexion angle is <10 degrees. LEVEL OF EVIDENCE: III.

Reliability of the Modified Method for Sphericity Deviation Score Using Only the Involved Hip Radiographs in the Patients With Legg-Calve-Perthes Disease.

BACKGROUND: The sphericity deviation score (SDS) is a validated radiographic outcome measure that quantifies the severity of the femoral head deformity in the healed stage of Legg-Calve-Perthes disease (LCPD). The current method requires radiographs of both hips regardless of unilateral involvement to standardize radiographic magnification. As LCPD affects the unilateral hip in 85% to 90% of cases, the current method imposes unnecessary radiation exposure to most of the patients and having to exclude patients from research studies who only had unilateral hip radiographs. We thus modified the SDS method to use unilateral hip radiographs. The purpose of this study was to investigate the reliability of the modified SDS method using the radiographs containing only one hip. METHODS: This retrospective study involved 40 patients with LCPD with unilateral involvement in the healed stage of LCPD. We modified the SDS measurement method by using the distance between the teardrop and the lateral acetabulum for magnification correction and providing a clear anatomic description of reference points on the femoral head. Three independent observers performed measurements using radiographs containing the affected hip only (modified method) and both hips (conventional method). The intraclass correlation (ICC) estimates were calculated. To verify clinical relevance, the correlation of the SDS with the Stulberg classification and hip range of motion (ROM) were also investigated. RESULTS: Measurements using the modified SDS showed excellent inter-/intra-observer ICCs (0.903 to 0.978). The ICCs between the modified and conventional methods were also excellent: 0.940 to 0.966 within the same observer and 0.897 to 0.919 between different observers. The modified SDS showed moderate-to-strong correlations with the Stulberg classification (Spearman ρ=0.650) and hip ROM (Pearson r =-0.661). CONCLUSION: The modified SDS measurement method showed excellent inter-/intra-observer reliability and moderate-to-strong correlations with the Stulberg classification and hip ROM. This method will help reduce unnecessary radiation exposure in patients with unilateral LCPD and prevent the exclusion of patients with unilateral radiographs from future research studies. LEVEL OF EVIDENCE: Level III-diagnostic study.

Injury-mechanism directness as a key factor for fracture laterality in pediatric extremity fractures.

BACKGROUND: Associations between certain extremity fracture sites and laterality in pediatric trauma are well known, whereas the rationale for such laterality tendencies are unclear. We hypothesized that the laterality tendency of a specific fracture would be affected by directness of injury mechanism and not by the fracture site itself. METHODS: We retrospectively enrolled 1382 children (aged 2-16 years) who were diagnosed with extremity fractures sustained during loss-of-balance situations and investigated the laterality tendencies (dominant vs. non-dominant extremity) of specific fracture sites. Multivariate analyses were sequentially performed to adjust for potential confounding variables-with and without injury-mechanism directness as a covariate. RESULTS: In the upper extremities, the non-dominant side was more prone to fractures (p < 0.001), especially of the distal supracondylar humerus, radial and/or ulnar shaft, and distal radius. In the lower extremities, the dominant side was more frequently fractured (p < 0.001), especially at the tibial shaft and distal tibia. However, the predisposing effects of specific fracture sites on fracture laterality were not statistically significant when in analysis adjusted for injury-mechanism directness as a covariate. Fracture laterality was affected by whether the injury mechanism was direct or indirect. Indirect injury to the upper extremity was strongly associated with non-dominant arm injury (odds ratio 0.686 [95% CI 0.517-0.991]; p = 0.009), whereas indirect injury to the lower extremity was strongly associated with dominant leg injury (odds ratio 2.138 [95% CI 1.444-3.165]; p < 0.001). CONCLUSIONS: Injury-mechanism directness, rather than fracture site itself, is a key factor that affects fracture laterality in pediatric extremity fractures. These findings are helpful for improving our understanding of which factors may affect fracture laterality among children.

A comparative retrospective study of different surgical guide designs for static computer-assisted implant surgery in posterior single edentulous sites.

AIM: The aim of this retrospective clinical study was to compare the accuracy of static Computer-assisted implant surgery (sCAIS) in posterior single edentulous patients using different surgical guide designs. MATERIALS AND METHODS: Thirty-seven partially edentulous patients with a total of 54 implants were included in the study. Seventeen implants were included in Group 1-Unbounded Tooth-Mucosa Supported; 18 implants in Group 2-Unbounded Tooth Supported; and 19 implants in Group 3 (Control)-Bounded Tooth Supported. All partially edentulous patients were treated with fully guided implant surgery using the corresponding surgical guide. Discrepancies between the pre-planned and post-operative implant position were evaluated. RESULTS: The mean angular deviation ± standard deviation (SD) was 2.91 ± 1.56°, 3.33 ± 1.72° and 2.25 ± 1.13° for Groups 1, 2, and 3, respectively. The mean ± SD 3D offset at base was 0.66 ± 0.29 mm, 0.77 ± 0.24 mm, and 0.49 ± 0.22 mm; and 3D offset at tip was 0.84 ± 0.45 mm, 1.07 ± 0.38 mm, and 0.75 ± 0.25 mm for Groups 1, 2, and 3, respectively. No statistically significant differences between groups were found for angular deviation. There were statistically significant differences between Groups 2 and 3 for 3D offset at base (p = .002) and 3D offset at tip (p = .010). CONCLUSIONS: Different surgical guide designs for posterior single edentulous areas appear to be associated with the accuracy level of sCAIS. In unbounded sites, having additional posterior attached soft tissue support is preferable.

Decellularized Bovine Pericardial Patch Loaded With Mesenchymal Stromal Cells Enhance the Mechanical Strength and Biological Healing of Large-to-Massive Rotator Cuff Tear in a Rat Model.

PURPOSE: The purpose of this study was to determine whether the addition of decellularized bovine pericardial patch loaded with mesenchymal stromal cells enhanced bone-to-tendon healing and improved the biomechanical strength of large-to-massive rotator cuff tears in a small animal model. METHODS: Adipose-derived mesenchymal stromal cells (MSCs) from rat inguinal fat were isolated, cultured, and loaded onto decellularized bovine pericardium patches. To simulate large-to-massive tears, rats were managed with free cage activity for 6 weeks after tear creation. A total of 18 rats were randomly allocated to repair-only (control), repair with pericardial patch augmentation (patch), or repair with MSC loaded pericardial patch augmentation (patch-MSC). Each group had 6 rats (one shoulder of each rat was used for histological evaluation and another for biomechanical evaluation). MSCs seeded on the pericardial patches were traced on four shoulders from 2 other rats at 4 weeks after surgery. Histological evaluation for bone-to-tendon healing and biomechanical testing was carried out at 8 weeks after repair. RESULTS: MSCs tagged with a green fluorescent protein were observed in the repair site 4 weeks after the repair. One shoulder each in the control and patch groups showed complete discontinuity between the bone and tendon. One shoulder in the control group showed attenuation with only a tenuous connection. Fibrocartilage and tidemark formation at the bone-to-tendon interface (P = .002) and collagen fiber density (P = .040) and orientation (P = .003) were better in the patch-MSC group than in the control or patch group. Load-to-failure in the patch-MSC and patch groups was higher than that in the control group (P = .001 and .009, respectively). CONCLUSION: Decellularized bovine pericardial patches loaded with adipose-derived and cultured mesenchymal stromal cells enhanced healing in terms of both histology and mechanical strength at 8 weeks following rotator cuff repair in a rat model. CLINICAL RELEVANCE: Large-to-massive rotator tears need a strategy to prevent retear and enhance healing. The addition of decellularized bovine pericardial patch loaded with MSCs can enhance bone-to-tendon healing and improve biomechanical healing of large-to-massive rotator cuff tears following repair.

Analysis of Tertiary Hospital Utilization in Pediatric Orthopaedics: a Study Using Nationwide Sample Data from Korea.

BACKGROUND: In the Korean medical system, the severity classification for a specific disease depends primarily on its nationwide admission rate in tertiary hospitals. Inversely, one of the important designation criteria for a tertiary hospital is the hospital's treatment ratio of patients classified as having a specific severe disease. Most diseases requiring pediatric orthopaedic surgery (POS) are not currently classified as high severity in terms of disease severity. We investigated the admission rates for the representative POS diseases in tertiary hospitals and compared these rates with those for adult orthopaedic surgery (AOS) diseases. METHODS: Seven POS diagnoses and three AOS diagnoses were selected based on frequency of admission. Nationwide sample data were used to investigate the admission rates for these representative diagnoses from 2008 to 2017. RESULTS: Six of the seven frequent POS diagnoses presented high admission rates in tertiary hospitals (62.5-92.3%). In contrast, all frequent AOS diagnoses presented low admission rates in tertiary hospitals. CONCLUSION: The admission rates of frequent POS diagnoses in tertiary hospitals are high. Considering that these rates are the most important factors for the classification of disease severity, POS diseases seem to be underestimated in terms of severity. This may lead to a tendency for tertiary hospitals to intentionally reduce the admission of children with POS diseases. As a result, these children may not receive appropriate professional care. Therefore, for the disease severity, POS diseases should be classified differently from general AOS diseases by using different criteria reflecting the patient's age.

Classification of Middle Phalangeal Postaxial Polysyndactyly Based on Intraoperative Arthrography Is Useful for Surgical Decision-making in Children Younger Than 2 Years.

BACKGROUND: The middle phalangeal type of postaxial polysyndactyly (MPPP) of the foot is a common congenital limb anomaly and is usually treated surgically at a young age. Owing to the insufficiency of radiologic evaluation due to largely cartilaginous portions of the pediatric foot, we performed intraoperative arthrography (IOA) for MPPP. This study was aimed at presenting a new classification system for foot MPPP in young children based on IOA findings and investigating its intraoperative decision-making. METHODS: Thirty-seven patients aged below 2 years who underwent IOA and surgical treatment of foot MPPP in our institute between January 2018 and April 2020 were retrospectively reviewed. The mean patient age at operation was 1.31 years (range, 0.91 to 1.99 y). IOA was performed in the common proximal interphalangeal (PIP) joint. The excisional level and side were determined on the basis of the IOA findings and bony alignment between the proximal and distal phalanges for functional and cosmetic purposes. Arthrographic findings and surgical procedures were recorded. RESULTS: A new classification divided MPPP into 2 major types according to the presence (type A) or absence (type B) of longitudinal contrast filling between the fifth and sixth middle phalanges. These 2 major types were further divided into 4 subtypes according to the shape of the PIP joint by contrast filling. There were 19, 15, and 3 cases of type A, B, and indeterminate IOA. Fifth and sixth ray excisions were performed in 26 and 11 cases, respectively. Interobserver reliability of the classification represented excellent agreement (Cohen κ coefficient=0.823). CONCLUSIONS: Our new classification based on IOA helped determine the articular dominance and its detailed morphology, which can help predict postoperative stability and mobility of the remaining toe. IOA is a simple, safe, and useful imaging tool for the surgical treatment of foot MPPP in patients aged below 2 years. LEVEL OF EVIDENCE: Level III.

Physeal Abnormalities in Children With High-risk Neuroblastoma Intensively Treated With/Without 13-Cis-Retinoic Acid.

BACKGROUND: This study aimed to investigate the presence of physeal abnormality and its effect on growth in children with high-risk neuroblastoma treated by intensive multimodal treatment with/without 13-cis-retinoic acid (13-CRA). METHODS: Fifteen patients diagnosed with high-risk neuroblastomas at the age of 1 to 10 years, who received treatment such as high-dose chemotherapy and autologous stem cell transplantation with/without 13-CRA, and with complete data during their >2-year follow-up were retrospectively reviewed. The physeal abnormalities were investigated by whole-body magnetic resonance imaging, serially performed every 3 to 6 months. The patients' height growth was also investigated and compared with that of age-and-sex-matched patients with brain tumors who also underwent high-dose chemotherapy and autologous stem cell transplantation. RESULTS: Six of 15 patients presented multifocal physeal abnormalities during follow-up, and all lesions occurred in patients with 13-CRA use. The lesions in 3 patients completely resolved spontaneously without any adverse effect on growth, but some lesions in the other 3 patients progressed to disturb the bony growth. Height growth of matched patients with brain tumors were not significantly different, and none of the matched controls showed definite bony deformity during the follow-up. CONCLUSIONS: Some children who were treated for high-risk neuroblastomas experienced multifocal physeal insults, probably due to the use of 13-CRA. Most lesions resolved spontaneously, but some led to bony deformity. If the lesions are not followed by premature physeal closure, there seems to be no further adverse effect of 13-CRA on leg length growth. Routine periodic screening for physeal status is needed for the patients with high-risk neuroblastomas using 13-CRA. LEVEL OF EVIDENCE: Level IV-prognostic study.

Prediction of High-Grade Hip Joint Effusion With Simple Radiographs in Children: A Comparative Study With Magnetic Resonance Imaging.

OBJECTIVES: The objective of this study was to investigate the predictive value of asymmetric joint space widening on simple radiographs for the presence of hip joint effusion in children with unilateral hip pain. METHODS: Sixty-eight patients aged 6 to 17 years with both simple radiograph and magnetic resonance imaging of both hips were retrospectively reviewed. We evaluated the predictive effects of radiographic surrogates for joint space widening on the presence of high-grade hip joint effusion. We also sought to investigate a predictive model for the presence of hip joint effusion with the patients' clinical and radiological data. RESULTS: Radiographic values showed high specificity but low sensitivity for the presence of high-grade joint effusion. On multivariate analysis, sex and the difference ratio of medial and superior gaps were independent predictive factors for unilateral high-grade hip joint effusion. CONCLUSIONS: For children 6 years and older with asymmetric hip joint space widening on simple radiographs, further evaluations for the presence of hip joint effusion should be considered because of its high specificity. The predictability can improve if both medial and superior gaps, and sex are included in the evaluation. In girls, hip joint effusion seems to widen the joint space more easily than in boys, which may be owing to the more ligamentous laxity of and less musculature around the hip in girls. However, the risk of joint effusion should not be underestimated even if a child presents symmetry on the simple radiograph because of its low sensitivity and the possibility of bilateral involvements or early stage of diseases.

Agreement of Postoperative Pain Assessment by Parents and Clinicians in Children Undergoing Orthopedic Surgery.

BACKGROUND: Postoperative pain assessment in children is crucial for proper nursing care. However, research on the agreement of these assessments with a patient's self-reported pain level is lacking. The aim was to investigate the agreement between patients' subjective postoperative pain and corresponding observers' pain assessments. METHODS: In children who underwent orthopedic limb surgery, we investigated the agreement between their reported pain levels and observers' pain assessments using the Numeric Pain Rating Scale (NPRS) and the Faces Pain Scale-Revised (FPS-R) on postoperative day 1. The parents (specifically the mother) and clinicians (a doctor and a nurse in the field of pediatric orthopedics) participated as observers. Reliabilities using intraclass correlation coefficients (ICCs) and correlations using Spearman's coefficients (rs) were calculated. RESULTS: The patients' pain intensities (2.1± 2.1 [NPRS] and 2.0 ± 1.9 [FPS-R]) were overestimated by parents (2.5 ± 2.0 [NPRS], p = .022), but underestimated by clinicians (1.5 ± 1.2 [NPRS], p < .001, and 1.5 ± 1.2 [FPS-R], p = .006). The overall reliabilities between parents and patients were good (ICCs > 0.75 for both NPRS and FPS-R), and the correlations between them were even strong in some circumstances, such as when the patient was a girl, the diagnostic type was a disease, or the lower extremity was operated (rss > 0.7). However, the agreements between clinicians and patients were only moderate. CONCLUSIONS: The subjective pediatric postoperative pain intensities had different agreements according to the observers. The parents' assessments should be considered for the accurate assessments, but their tendency to overestimate their children's pain should also be taken into account.

Outcomes of Arthroscopy-assisted Closed Reduction and Percutaneous Pinning for a Displaced Pediatric Lateral Condylar Humeral Fracture.

BACKGROUND: Since 2015, we have performed arthroscopy-assisted closed reduction and percutaneous pinning (A/S-CRPP) for children with a displaced lateral condylar humeral fracture (LCF). The purpose of this study is to introduce our A/S-CRPP method and present its outcomes. METHODS: In total, 39 displaced (>2 mm) LCFs for which A/S-CRPP was initially attempted and with available follow-up data of >12 months were retrospectively reviewed. A/S-CRPP is performed in the following order: closed reduction, 1 provisional K-wire fixation, arthroscopic verification of the reduction status, rereduction if needed, and additional fixation. Our reduction technique using articulations of the ulnohumeral and radiohumeral joints and direct compression is introduced. For rereduction, modified reduction forces were applied based on the arthroscopic findings. To evaluate the learning curve effect, the initial 6 months after the first case of A/S-CRPP was regarded as the "initial period." There were 12 cases during this period. RESULTS: Among the 39 cases, surgical method was intraoperatively converted to open reduction and percutaneous pinning in 9 and A/S-CRPP was completed in 30. Among the 9 open reduction and percutaneous pinning conversion cases, 7 conversions occurred in the initial period. Among the 30 patients who underwent A/S-CRPP alone, 10 needed rereduction after an arthroscopic examination. No patients presented with >10-degree angular deformity or elbow motion limited >20 degrees, compared with the contralateral elbow. Postoperative radial nerve palsy occurred in 2 patients, all in the initial period. Both were resolved within 5 months, postoperatively. CONCLUSIONS: We suggested our A/S-CRPP surgical technique for displaced pediatric LCF. It may require a 6-month learning curve period. Although more studies are needed, it seems to be a safe and appropriate surgical technique for treatment. LEVEL OF EVIDENCE: Level IV-therapeutic study.

Prediction of the Peripheral Rim Instability of the Discoid Lateral Meniscus in Children by Using Preoperative Clinicoradiological Factors.

BACKGROUND: The discoid lateral meniscus (DLM) in children often presents peripheral rim instability (PRI) and is susceptible to tear or subluxation, which manifests symptoms and leads to a poor prognosis. We aimed to investigate the association between preoperative clinical and MRI findings and the intraoperative findings of PRI. METHODS: Children and adolescents aged younger than 16 years who underwent surgical treatment for DLM were retrospectively reviewed. Cases of bucket-handle tear were not included because they would confound the stability of the peripheral rim. Total 60 knees from 47 children were included. PRI was additionally subdivided based on the location, such as anterior, middle, and posterior, during the investigation. RESULTS: In multivariate analyses, both central (inward) (P=0.004) and external (outward) (P=0.029) displacement of lateral meniscal margin, and peripheral tear of the anterior body (P=0.022) were significant predictors of PRI, regardless of the location. The predictive factors for PRI based on each location were female gender (P=0.004), subjective symptom of clicking sound (P=0.023), and central displacement of the anterior meniscal margin (P=0.034) for anterior PRI; flexion contracture >10 degrees (P=0.017) and peripheral tear of the middle body (P<0.001) for middle PRI; and central displacement of the posterior meniscal margin (P=0.036) and peripheral tears of the anterior (P=0.029) and middle bodies (P=0.047) for posterior PRI. CONCLUSIONS: We evaluated the preoperative clinical and MRI findings that predict PRI of pediatric DLM. Displacements of the DLM, not only centrally (inward) but also externally (outward), seem to be significant predictive factors for PRI. Furthermore, some clinical findings were associated with PRI, even predicting the locations. Although the actual surgical procedure should be determined by meticulous probing during arthroscopy, preoperative prediction of the presence and location of PRI would help decrease the risk of oversight during surgery. LEVEL OF EVIDENCE: Level III-Diagnostic Study.

Dynamics of Mechanosensitive Neural Stem Cell Differentiation.

Stem cell differentiation can be highly sensitive to mechanical inputs from the extracellular matrix (ECM). Identifying temporal windows during which lineage commitment responds to ECM stiffness, and the signals that mediate these decisions, would advance both mechanistic insights and translational efforts. To address these questions, we investigate adult neural stem cell (NSC) fate commitment using an oligonucleotide-crosslinked ECM platform that for the first time offers dynamic and reversible control of stiffness. "Stiffness pulse" studies in which the ECM was transiently or permanently softened or stiffened at specified initiation times and durations pinpoint a 24-hour window in which ECM stiffness maximally impacts neurogenic commitment. Overexpression of the transcriptional coactivator Yes-associated protein (YAP) within this window suppressed neurogenesis, and silencing YAP enhanced it. Moreover, ablating YAP-ß-catenin interaction rescued neurogenesis. This work reveals that ECM stiffness dictates NSC lineage commitment by signaling via a YAP and ß-catenin interaction during a defined temporal window. Stem Cells 2017;35:497-506.

Dental Implant Therapy on a Patient With von Willebrand Disease: A Case Study.

BACKGROUND: Von Willebrand disease (vWD) is the most common hereditary disorder affecting coagulation. Patients with this disorder are at a higher risk of postoperative complications after dental surgery. This article discusses the successful treatment for a patient with vWD undergoing implant therapy. CASE DESCRIPTION: A young 21-year-old patient with vWD lost tooth #30 because of caries and required implant therapy. Through collaboration with a hematologist administering prophylactic desmopressin (DDAVP), the implant surgery was performed without any postoperative complications. The implant successfully integrated and was restored into function. The successful outcome met expectations after careful planning and execution. PRACTICAL IMPLICATIONS: Collaboration with the appropriate medical providers, as well as treatment modifications for surgical procedures during implant therapy, is necessary for successful treatment of a patient with von Willebrand disorder.

Real-Time Risk Prediction on the Wards: A Feasibility Study.

OBJECTIVE: Failure to detect clinical deterioration in the hospital is common and associated with poor patient outcomes and increased healthcare costs. Our objective was to evaluate the feasibility and accuracy of real-time risk stratification using the electronic Cardiac Arrest Risk Triage score, an electronic health record-based early warning score. DESIGN: We conducted a prospective black-box validation study. Data were transmitted via HL7 feed in real time to an integration engine and database server wherein the scores were calculated and stored without visualization for clinical providers. The high-risk threshold was set a priori. Timing and sensitivity of electronic Cardiac Arrest Risk Triage score activation were compared with standard-of-care Rapid Response Team activation for patients who experienced a ward cardiac arrest or ICU transfer. SETTING: Three general care wards at an academic medical center. PATIENTS: A total of 3,889 adult inpatients. MEASUREMENTS AND MAIN RESULTS: The system generated 5,925 segments during 5,751 admissions. The area under the receiver operating characteristic curve for electronic Cardiac Arrest Risk Triage score was 0.88 for cardiac arrest and 0.80 for ICU transfer, consistent with previously published derivation results. During the study period, eight of 10 patients with a cardiac arrest had high-risk electronic Cardiac Arrest Risk Triage scores, whereas the Rapid Response Team was activated on two of these patients (p < 0.05). Furthermore, electronic Cardiac Arrest Risk Triage score identified 52% (n = 201) of the ICU transfers compared with 34% (n = 129) by the current system (p < 0.001). Patients met the high-risk electronic Cardiac Arrest Risk Triage score threshold a median of 30 hours prior to cardiac arrest or ICU transfer versus 1.7 hours for standard Rapid Response Team activation. CONCLUSIONS: Electronic Cardiac Arrest Risk Triage score identified significantly more cardiac arrests and ICU transfers than standard Rapid Response Team activation and did so many hours in advance.

The Effect of Taper Angle and Spline Geometry on the Initial Stability of Tapered, Splined Modular Titanium Stems.

Design parameters affecting initial mechanical stability of tapered, splined modular titanium stems (TSMTSs) are not well understood. Furthermore, there is considerable variability in contemporary designs. We asked if spline geometry and stem taper angle could be optimized in TSMTS to improve mechanical stability to resist axial subsidence and increase torsional stability. Initial stability was quantified with stems of varied taper angle and spline geometry implanted in a foam model replicating 2cm diaphyseal engagement. Increased taper angle and a broad spline geometry exhibited significantly greater axial stability (+21%-269%) than other design combinations. Neither taper angle nor spline geometry significantly altered initial torsional stability.

New-Onset Paroxysmal Atrial Fibrillation in a Healthy Male With Post-COVID-19 Painless Thyroiditis: A Case Report.

Painless thyroiditis is a variant of thyroiditis without the typical neck pain and is otherwise similar to subacute thyroiditis, which is a known post-viral condition and has been associated with coronavirus disease 2019 (COVID-19) infections. While it is usually self-limiting, it can lead to thyrotoxicosis that can predispose individuals to cardiac dysrhythmias, including atrial fibrillation. There has been a clear association between COVID-19 and subacute thyroiditis with a few case reports describing atrial fibrillation. We present a case of a healthy patient with new-onset atrial fibrillation secondary to painless thyroiditis. This report highlights the rare entity of painless thyroiditis leading to atrial fibrillation with rapid ventricular response in a patient who recently recovered from COVID-19. Physicians should consider the potential association of painless thyroiditis in patients with new-onset atrial fibrillation who recently recovered from COVID-19.

Protocol for extracting and isolating porcine bone-marrow-derived macrophages from ribs.

Due to anatomical and biological similarities with humans, pigs are increasingly used for inflammation- and immune-related studies in biomedical research, including the field of osteonecrosis and osteoimmunology. Here, we present a protocol for rib extraction, isolation of the bone marrow by centrifugation, and processing to obtain bone-marrow-derived macrophages (BMDMs). Then, we describe the procedures of in vitro experiments to evaluate the cell phenotype. For complete details on the use and execution of this protocol, please refer to Andre et al.1.