Does Tranexamic Acid Reduce the Need for Hypotensive Anesthesia Within Orthognathic Surgery? A Retrospective Study.

Background: Tranexamic acid (TXA) is utilized frequently in orthognathic surgery to limit blood loss and improve surgical field visualization. This antifibrinolytic has been proven effective with use of concomitant hypotensive anesthesia. Despite proven efficacy, there is a recent push to avoid perioperative hypotensive anesthesia due to risks of organ hypoperfusion, cardiac ischemia and postoperative nausea. Aims: The aim is to study the efficacy and safety of utilizing TXA without controlled hypotensive anesthesia. Methods: The authors identified two cohorts of subjects that underwent bimaxillary orthognathic surgery both with and without TXA administration and compared operative and perioperative variables. A retrospective analysis was completed evaluating intraoperative MAP measurements in subjects treated both with and without TXA using descriptive and bivariate analysis. Results and conclusion: Sixty-three subjects met inclusion criteria. The TXA cohort experienced 11.5% less time under hypotensive anesthesia when compared to the group that did not receive TXA. Additionally, surgical length was decreased by more than 28 min when subjects received TXA. No subjects required a blood transfusion or experienced any TXA-related complications. Given the recommendations to limit hypotensive anesthesia perioperatively, TXA is a useful adjunct in orthognathic surgery to limit controlled hypotensive anesthesia.

Rapid examination of lung tissues by nonlinear microscopy.

OBJECTIVES: Traditional histopathology is a time-intensive and labor-intensive process involving tissue formalin fixation, paraffin embedding, and microtoming into thin sections for H&E staining. Frozen section analysis is a modality used during surgery to quickly evaluate tissue, but it has limitations, such as the size and number of the specimens that can be analyzed as well as difficulties with fatty and bony tissues. Our objective was to investigate the performance of nonlinear microscopy, a fluorescence microscopy technique, for the rapid examination of resected lung tumors. METHODS: In this proof-of-principle study, nonlinear microscopy imaging of resected lung tissue was performed on a total of 73 tissue specimens collected from 13 patients who underwent lobectomy, segmentectomy, or wedge resection for pulmonary nodules. RESULTS: Two pathologists reviewed the digital nonlinear microscopy images in comparison to the corresponding histopathologic H&E slides from a variety of pulmonary pathologies. CONCLUSIONS: This study demonstrated that nonlinear microscopy readily replicates traditional H&E staining for both lung tumors and nonneoplastic pulmonary structures. Nonlinear microscopy provides many advantages over frozen section analysis and is an optical imaging platform that has the potential to augment rapid pathologic evaluation of resected tissues in the age of digital pathology.

Data retrieval from archival renal biopsies using nonlinear microscopy.

Thorough examination of renal biopsies may improve understanding of renal disease. Imaging of renal biopsies with fluorescence nonlinear microscopy (NLM) and optical clearing enables three-dimensional (3D) visualization of pathology without microtome sectioning. Archival renal paraffin blocks from 12 patients were deparaffinized and stained with Hoechst and Eosin for fluorescent nuclear and cytoplasmic/stromal contrast, then optically cleared using benzyl alcohol benzyl benzoate (BABB). NLM images of entire biopsy fragments (thickness range 88-660 µm) were acquired using NLM with fluorescent signals mapped to an H&E color scale. Cysts, glomeruli, exudative lesions, and Kimmelstiel-Wilson nodules were segmented in 3D and their volumes, diameters, and percent composition could be obtained. The glomerular count on 3D NLM volumes was high indicating that archival blocks could be a vast tissue resource to enable larger-scale retrospective studies. Rapid optical clearing and NLM imaging enables more thorough biopsy examination and is a promising technique for analysis of archival paraffin blocks.

Rapid Examination of Nonprocessed Renal Cell Carcinoma Using Nonlinear Microscopy.

CONTEXT.­: Histology, the traditional method of examining surgical tissue under a microscope, is a time-consuming process involving the fixation of tissue in formalin, dehydration, embedding in paraffin, and cutting into thin sections for hematoxylin-eosin (H&E) staining. Frozen section analysis is a faster alternative used in surgery to quickly evaluate tissue, but it has limitations, such as the size of the specimens that can be analyzed and difficulties with fatty and bony tissues. OBJECTIVE.­: To rapidly examine nonprocessed kidney tumors using nonlinear microscopy (NLM), a fluorescence microscopy technique that can rapidly visualize fresh or fixed, rapidly stained, nonprocessed tissue resembling H&E histology. This technology eliminates the need for fixation, embedding, microtome sectioning, or slide preparation. DESIGN.­: In this study, a total of 190 tissue specimens were collected from 46 patients who underwent partial or radical nephrectomy. RESULTS.­: Two genitourinary pathologists confirmed that diagnostically important features present in the H&E images could also be identified in the NLM images. CONCLUSIONS.­: The results of this study demonstrated that NLM had a high degree of correspondence with H&E staining for the classical variants of renal cell carcinoma. NLM offers several clinical benefits, such as facilitating rapid renal cell carcinoma diagnosis, assessment of targeted kidney biopsies for both tumor and medical kidney diseases, and collection of fresh renal cell carcinoma tissue for molecular studies.

What Is Health Literacy Among Orthognathic Surgery Patients?

BACKGROUND: Health literacy of orthognathic surgery patients has not been thoroughly evaluated. PURPOSE: The purpose of this study was to estimate health literacy and identify risk factors associated with inadequate health literacy in orthognathic surgery patients. STUDY DESIGN, SETTING, SAMPLE: A cross-sectional study was implemented utilizing patients ages 14-80 years who presented for orthognathic surgery evaluation between September 2021 and December 2022. Subjects were excluded from the study if they did not complete the orthognathic surgery evaluation, were not between the ages of 14-80 years old, or did not complete the Brief Health Literacy Screening Tool (BRIEF) questionnaire during intake. Subjects who have not undergone orthognathic surgery but completed the initial evaluation for orthognathic surgery were included in the study. PREDICTOR VARIABLES: The predictor variables were a set of risk factors for inadequate health literacy: age, sex, primary language, race, estimated household income, and diagnosis. MAIN OUTCOME VARIABLE: The main outcome variable was health literacy assessed using the BRIEF questionnaire. During intake, subjects completed the BRIEF questionnaire consisting of four questions scored on an ordinal scale of 1-5. Inadequate health literacy was defined as a BRIEF score ≤16. COVARIATES: Not applicable. ANALYSES: Bivariate and multivariate analyses were performed. P < .05 was considered statistically significant. RESULTS: Of 150 patients presenting for orthognathic surgery, fifteen percent of patients had inadequate health literacy via the BRIEF test. The mean age of those with adequate health literacy was 27.9 years (standard deviation, ±12.5) compared to 18.5 years (standard deviation, ±5.7) for those with inadequate health literacy (P = <.001). After adjusting for sex, language, race, estimated household income, and diagnosis via multivariate analysis, increasing age was associated with decreased odds of inadequate health literacy (adjusted odds ratio = 0.81; confidence interval, 0.72-0.92; P = <.001). CONCLUSION AND RELEVANCE: In the complex process of orthognathic surgery, it is essential to identify patients with inadequate health literacy that may require additional health literacy interventions. Ultimately, 15% of orthognathic surgery subjects had inadequate health literacy, and younger patients were the most susceptible as the odds of inadequate health literacy decreased with increasing age.

Retrograde Intramedullary Nailing Versus Locked Plating for Extreme Distal Periprosthetic Femur Fractures: A Multicenter Retrospective Cohort Study.

OBJECTIVES: To compare clinical and radiographic outcomes after retrograde intramedullary nailing (rIMN) versus locked plating (LP) of "extreme distal" periprosthetic femur fractures, defined as those that contact or extend distal to the anterior flange. DESIGN: Retrospective review. SETTING: Eight academic level I trauma centers. PATIENT SELECTION CRITERIA: Adult patients with periprosthetic distal femur fractures at or distal to the anterior flange (OTA/AO 33B-C[VB1]) treated with rIMN or LP. OUTCOME MEASURES AND COMPARISONS: The primary outcome was reoperation to promote healing or to treat infection (reoperation for elective removal of symptomatic hardware was excluded from this analysis). Secondary outcomes included nonunion, delayed union, fixation failure, infection, overall reoperation rate, distal femoral alignment, and ambulatory status at final follow-up. Outcomes were compared between patients treated with rIMN or LP. RESULTS: Seventy-one patients treated with rIMN and 224 patients treated with LP were included. The rIMN group had fewer points of fixation in the distal segment (rIMN: 3.5 ± 1.1 vs. LP: 6.0 ± 1.1, P < 0.001) and more patients who were allowed to weight-bear as tolerated immediately postoperatively (rIMN: 45%; LP: 9%, P < 0.01). Reoperation to promote union and/or treat infection was 8% in the rIMN group and 16% in the LP group ( P = 0.122). There were no significant differences in nonunion ( P > 0.999), delayed union ( P = 0.079), fixation failure ( P > 0.999), infection ( P = 0.084), or overall reoperation rate ( P > 0.999). Significantly more patients in the rIMN group were ambulatory without assistive devices at final follow-up (rIMN: 35%, LP: 18%, P = 0.008). CONCLUSIONS: rIMN of extreme distal periprosthetic femur fractures has similar complication rates compared with LP, with a possible advantage of earlier return to weight-bearing. Surgeons can consider this treatment strategy in all fractures with stable implants and amenable prosthesis geometry, even extreme distal fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

High-speed multiplane confocal microscopy for voltage imaging in densely labeled neuronal populations.

Genetically encoded voltage indicators (GEVIs) hold immense potential for monitoring neuronal population activity. To date, best-in-class GEVIs rely on one-photon excitation. However, GEVI imaging of dense neuronal populations remains difficult because out-of-focus background fluorescence produces low contrast and excess noise when paired with conventional one-photon widefield imaging methods. To address this challenge, we developed an imaging system capable of efficient, high-contrast GEVI imaging at near-kHz rates and demonstrate it for in vivo and ex vivo imaging applications in the mouse neocortex. Our approach uses simultaneous multiplane imaging to monitor activity within contiguous tissue volumes with no penalty in speed or requirement for high excitation power. This approach, multi-Z imaging with confocal detection (MuZIC), permits high signal-to-noise ratio voltage imaging in densely labeled neuronal populations and is compatible with imaging through micro-optics. Moreover, it minimizes artifacts associated with concurrent imaging and optogenetic photostimulation for all-optical electrophysiology.

Sensitivity optimization of a rhodopsin-based fluorescent voltage indicator.

The ability to optically image cellular transmembrane voltages at millisecond-timescale resolutions can offer unprecedented insight into the function of living brains in behaving animals. Here, we present a point mutation that increases the sensitivity of Ace2 opsin-based voltage indicators. We use the mutation to develop Voltron2, an improved chemigeneic voltage indicator that has a 65% higher sensitivity to single APs and 3-fold higher sensitivity to subthreshold potentials than Voltron. Voltron2 retained the sub-millisecond kinetics and photostability of its predecessor, although with lower baseline fluorescence. In multiple in vitro and in vivo comparisons with its predecessor across multiple species, we found Voltron2 to be more sensitive to APs and subthreshold fluctuations. Finally, we used Voltron2 to study and evaluate the possible mechanisms of interneuron synchronization in the mouse hippocampus. Overall, we have discovered a generalizable mutation that significantly increases the sensitivity of Ace2 rhodopsin-based sensors, improving their voltage reporting capability.

External Validation of the Radiographic Investigation of the Distal Extension of Fractures Into the Articular Surface of the Tibia (RIDEFAST Study).

OBJECTIVE: To test the external validity of the fracture to plafond (FTP-length of fracture/distance to plafond) ratio to rule out distal intra-articular fractures (DIA) in distal tibial shaft fractures at an independent tertiary trauma center. DESIGN: Retrospective cohort study. SETTING: Two Level 1 trauma centers. PATIENTS: Two hundred seventeen patients with a distal tibial shaft fracture in the model cohort and 146 patients in the validation cohort. INTERVENTION: Radiographic measurements to calculate FTP ratio. MAIN OUTCOME MEASUREMENTS: Calibration plots, area under receiver operating characteristic curve (AUC), and decision curve analyses to evaluate the external validity of FTP ratio to determine DIA. RESULTS: The AUC for the anteroposterior (AP) FTP ratio was 0.83 [95% confidence interval (CI) 0.78-0.88] in the model data set and 0.86 (95% CI 0.80-0.91) in the validation data set. The AUC for the lateral FTP ratio was 0.82 (95% CI 0.77-0.87) in the model data set and 0.82 (95% CI 0.75-0.88) in the validation data set. The previously established AP FTP cutoff ratio of 0.61 had a 94% negative predictive value in the model cohort and a 100% negative predictive value in the validation cohort. CONCLUSION: The FTP ratio is an effective and externally validated screening tool to rule out DIA in distal tibia shaft fractures. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Fast, multiplane line-scan confocal microscopy using axially distributed slits.

The inherent constraints on resolution, speed and field of view have hindered the development of high-speed, three-dimensional microscopy techniques over large scales. Here, we present a multiplane line-scan imaging strategy, which uses a series of axially distributed reflecting slits to probe different depths within a sample volume. Our technique enables the simultaneous imaging of an optically sectioned image stack with a single camera at frame rates of hundreds of hertz, without the need for axial scanning. We demonstrate the applicability of our system to monitor fast dynamics in biological samples by performing calcium imaging of neuronal activity in mouse brains and voltage imaging of cardiomyocytes in cardiac samples.

Development of Unity Simulator for Epidural Insertion Training for Replacing Current Lumbar Puncture Simulators.

We have recently developed the Unity Simulator for Epidural Insertion Training (USEIT) system that provides an innovative and relatively inexpensive virtual simulation approach for epidural training. This report describes the design and development process to produce the USEIT system.

Ultrasound differential phase contrast using backscattering and the memory effect.

We describe a simple and fast technique to perform ultrasound differential phase contrast (DPC) imaging in arbitrarily thick scattering media. Although configured in a reflection geometry, DPC is based on transmission imaging and is a direct analog of optical differential interference contrast. DPC exploits the memory effect and works in combination with standard pulse-echo imaging, with no additional hardware or data requirements, enabling complementary phase contrast (in the transverse direction) without any need for intensive numerical computation. We experimentally demonstrate the principle of DPC using tissue phantoms with calibrated speed-of-sound inclusions.

In vivo corneal and lenticular microscopy with asymmetric fundus retroillumination.

We describe a new technique for non-contact in vivo corneal and lenticular microscopy. It is based on fundus retro-reflection and back-illumination of the crystalline lens and cornea. To enhance phase-gradient contrast, we apply asymmetric illumination by illuminating one side of the fundus. The technique produces micron-scale lateral resolution images across a 1 mm diagonal field of view in the central cornea. We show representative images of the epithelium, the subbasal nerve plexus, large stromal nerves, dendritic immune cells, endothelial nuclei, and the anterior crystalline lens, demonstrating the potential of this instrument for clinical applications.

Novel Treatment for Recurrent Posttraumatic Hip Instability: A Case Report.

CASE: A 26-year-old woman sustained a traumatic right hip dislocation with posterior wall component in a motor vehicle collision. Initial treatment consisted of open reduction internal fixation of her posterior wall fracture. Six years later, she developed low-energy recurrent hip instability. Imaging demonstrated posterior capsular insufficiency and femoral retrotorsion. The patient underwent intertrochanteric femoral rotational osteotomy. Nine years postoperatively, the patient has returned to activity without restriction or subsequent dislocations. CONCLUSIONS: Recurrent posttraumatic hip instability requires careful identification of the etiology of instability. This case provides long-term follow-up after successful treatment with intertrochanteric femoral rotational osteotomy.

Non-mydriatic chorioretinal imaging in a transmission geometry and application to retinal oximetry.

The human retina is typically imaged in a reflection geometry, where light is delivered through the pupil and images are formed from the light reflected back from the retina. In this configuration, artifacts caused by retinal surface reflex are often encountered, which complicate quantitative interpretation of the reflection images. We present an alternative illumination method, which avoids these artifacts. The method uses deeply penetrating near-infrared (NIR) light delivered transcranially from the side of the head, and exploits multiple scattering to redirect a portion of the light towards the posterior eye. This unique transmission geometry simplifies absorption measurements and enables flash-free, non-mydriatic imaging as deep as the choroid. Images taken with this new transillumination approach are applied to retinal oximetry.

"Jelly VAC" for Negative-Pressure Therapy for Complex Wound Closure: A Report of Two Cases.

CASE: A 35-year-old man sustained an open calcaneal fracture with bone loss, and a 57-year-old woman sustained an avulsion of the entirety of the plantar skin. Both patients were treated with multiple debridements and soft-tissue coverage. "Jelly-VAC" (vacuum-assisted closure) therapy was used after each debridement and during the soft-tissue coverage. CONCLUSION: Jelly-VAC therapy is a promising alternative that allows negative-pressure therapy with the use of ultrasound jelly to prevent air leakage into the wound. We propose using this technique in areas where obtaining a seal is difficult, where VAC therapy is contraindicated because of adhesive dressings (i.e., with damaged or poor-quality skin), or when long-term VAC therapy is needed to prevent wound maceration or there is a need for "VAC holidays."

Patient Mortality in Geriatric Distal Femur Fractures.

OBJECTIVES: To estimate 1-year mortality rates in elderly patients who undergo operative treatment for distal femur fractures and identify potential risk factors for mortality. DESIGN: Retrospective chart review. SETTING: Level 1 and Level 2 trauma centers. PATIENTS/PARTICIPANTS: Two hundred eighty-three elderly patients (average age 76.0 years ± 9.8) who sustained distal femur fractures between 2002 and 2012. INTERVENTION: Fracture fixation of the distal femur. MAIN OUTCOME MEASURE: Survival up to 1 year after surgery. RESULTS: The 1-year mortality rate for distal femur fractures in elderly patients was 13.4%. There were no statistically significant differences in overall mortality between native bone and periprosthetic fractures, intramedullary nail or open reduction internal fixation, or across Orthopaedic Trauma Association fracture classifications. Overall patient mortality was significantly higher at 30 days (P = 0.036), 6 months (P = 0.019), and 1 year (P = 0.018), when surgery occurred more than 2 days from the injury. Mean Charlson Comorbidity Index scores were significantly lower in survivors versus nonsurvivors at all time intervals (30 days, P = 0.023; 6 months, P = 0.001 and 1 year P ≤ 0.001). A time to surgery of more than 2 days, regardless of baseline illness, did not result in improved survivability at 1 year. CONCLUSIONS: Overall mortality for distal femur fractures was 13.4% in the elderly population. A surgical treatment more than 2 days after injury was associated with increased patient mortality. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Intraosseous Plating for the Management of Cortical Defects.

The management of fractures with segmental bone loss or abundant comminution on the far cortex is often complicated by deformity or frank hardware failure. Using plate constructs that rely on off-axis loading may not be sufficient to support the limb until healing occurs. There are a number of techniques to mitigate this problem, notably the use of intramedullary nails and bicolumnar plating of the fracture. These techniques are not always possible and do come with the biologic cost of additional surgery. In this article, the authors present a technique along with 2 case examples of using plates in an intraosseous location that was described by Dr Mast in his classic orthopaedic text. By placing these plates in the intramedullary space and then interdigitating fixation from the standard cortical plate, a rigid "I-beam" of fixation can be created to mitigate the eccentric loading placed on extraosseous plates. This technique is especially useful in situations in which intramedullary nails are precluded (comminuted intraarticular and some periprosthetic fractures).

Neuronal imaging with ultrahigh dynamic range multiphoton microscopy.

Multiphoton microscopes are hampered by limited dynamic range, preventing weak sample features from being detected in the presence of strong features, or preventing the capture of unpredictable bursts in sample strength. We present a digital electronic add-on technique that vastly improves the dynamic range of a multiphoton microscope while limiting potential photodamage. The add-on provides real-time negative feedback to regulate the laser power delivered to the sample, and a log representation of the sample strength to accommodate ultrahigh dynamic range without loss of information. No microscope hardware modifications are required, making the technique readily compatible with commercial instruments. Benefits are shown in both structural and in-vivo functional mouse brain imaging applications.

Unstable Proximal Femur Fractures Treated With Proximal Femoral Locking Plates: A Retrospective, Multicenter Study of 111 Cases.

OBJECTIVES: A few small case series have found that proximal femur fractures treated with a proximal femur locking plate (PFLP) have experienced more failures than expected. The purpose of this study was to review the clinical results of patients with acute, unstable proximal femur fractures treated with proximal femoral locking plates in a large, multicenter patient cohort. DESIGN: This is a retrospective clinical study. SETTING: The study included patients from 12 regional trauma centers and tertiary referral hospitals. PATIENTS: One hundred eleven consecutive patients with unstable proximal femur fractures stabilized with a PFLP and having required clinical and radiographic follow-up at a minimum of 12 months after injury. INTERVENTION: Surgical repair of an unstable proximal femur fracture with a PFLP. MAIN OUTCOME MEASUREMENTS: Treatment failures (failure of fixation, nonunion, and malunion) and need for revision surgery. RESULTS: Forty-six patients (41.4%) experienced a major treatment failure, including failed fixation with or without nonunion (39), surgical malalignment or malunion (18), deep infection (8), or a combination of these. Thirty-eight (34%) patients underwent secondary surgeries, including 30 for failed fixation, nonunion, or both. Treatment failure was found to occur at a significantly higher rate in patients with major comorbidities, in femurs repaired in varus malalignment, and using specific plate designs. CONCLUSIONS: Proximal femoral locking plates are associated with a high complication rate, frequently requiring revision or secondary surgeries in the treatment of unstable proximal femur fractures. Given the high complication rate with PFLPs, careful attention to reduction, use of a PFLP implant, and consideration should be given to alternative implants or fixation techniques when appropriate. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.