Anterior-posterior Research Articles

The Influence of Perspective on Perception: Assessing Residue Across Planes of Videofluoroscopy.

(1) To determine whether perception of pharyngeal residue severity differs by view plane on videofluoroscopy. (2) To explore whether the Bolus Clearance Ratio (BCR) can be reliably applied in the anterior-posterior (AP) plane. (3) To investigate the relationship between perception of residue severity and BCR measures across view planes. Images of the same bolus condition in lateral and AP were rated using a simple 5-point ordinal descriptive scale (none, trace, mild, moderate, severe) by 225 speech-language pathologists via electronic survey. BCR measures were obtained for the same set of images from four trained raters. Wilcoxon signed-rank tests and cumulative mixed modeling were used to compare ratings by plane. BCR reliability was calculated using intraclass correlation coefficients. Perceptual ratings were compared with BCR measures using Spearman correlations. (1) Perception of residue severity was not consistent across plane in 9/10 image pairs (p < 0.05), with a significant fixed effect of plane on severity rating (β = 0.41; z = 7.27; p < 0.001). The directionality of differences varied by case. (2) Inter-rater reliability for BCR measures was good across lateral (intraclass correlation coefficient [ICC] = 0.82) and AP (ICC = 0.87) planes, with superior intra-rater reliability in AP (lateral ICC = 0.85; AP ICC = 0.98). (3) There was a strong positive correlation between perceptual ratings and BCR measures in both planes. Perception of pharyngeal residue severity differs between lateral and AP planes with inconsistent directionality raising important questions about the clinical implications of single plane studies. The BCR shows good-excellent reliability and strong correlation with perception across planes, offering a promising method for cross-plane quantification. Level III, diagnostic study with a gold standard Laryngoscope, 2024.

The Detection and Classification of Scaphoid Fractures in Radiograph by Using a Convolutional Neural Network

Objective: Scaphoid fractures, particularly occult and non-displaced fractures, are difficult to detect using traditional X-ray methods because of their subtle appearance and variability in bone density. This study proposes a two-stage CNN approach to detect and classify scaphoid fractures using anterior–posterior (AP) and lateral (LA) X-ray views for more accurate diagnosis. Methods: This study emphasizes the use of multi-view X-ray images (AP and LA views) to improve fracture detection and classification. The multi-view fusion module helps integrate information from both views to enhance detection accuracy, particularly for occult fractures that may not be visible in a single view. The proposed method includes two stages, which are stage 1: detect the scaphoid bone using Faster RCNN and a Feature Pyramid Network (FPN) for region proposal and small object detection. The detection accuracy for scaphoid localization is 100%, with Intersection over Union (IoU) scores of 0.8662 for AP views and 0.8478 for LA views. And stage 2: perform fracture classification using a ResNet backbone and FPN combined with a multi-view fusion module to combine features from both AP and LA views. This stage achieves a classification accuracy of 89.94%, recall of 87.33%, and precision of 90.36%. Results: The proposed model performs well in both scaphoid bone detection and fracture classification. The multi-view fusion approach significantly improves recall and accuracy in detecting fractures compared to single-view approaches. In scaphoid detection, both AP and LA views achieved 100% detection accuracy. In fracture detection, using multi-view fusion, the accuracy for AP views reached 87.16%, and for LA views, it reached 83.83%. Conclusions: The multi-view fusion model effectively improves the detection of scaphoid fractures, particularly in cases of occult and non-displaced fractures. The model provides a reliable, automated approach to assist clinicians in detecting and diagnosing scaphoid fractures more efficiently.

Anterior-Posterior View Acquisition During Videofluoroscopy: A Survey Study Exploring Influential Factors on Speech-Language Pathologists' Practice Patterns.

This study explored factors influencing speech-language pathologists' (SLPs') decision making surrounding anterior-posterior (AP) view inclusion practices during videofluoroscopic swallowing studies (VFSSs) in the United States. SLPs completing VFSSs were recruited to complete an online anonymous survey. Questions represented six constructs of interest including: (a) clinician demographics, (b) practice patterns, (c) diagnostic perceptions, (d) professional influences, (e) training and education, and (f) logistical facilitators and barriers. Binary logistic regression was used to explore the relationship between construct items and likelihood of AP view inclusion. A total of 136/213 (64%) of respondents reported obtaining an AP view routinely. Facilitators of AP view inclusion were post-acute work setting (OR = 3.40, p = .001); perception that department practices "probably" (OR = 5.65, p = .006) or "definitely" align (OR = 5.30, p = .006) with evidence-based practice; perception the AP view has "a lot" (OR = 4.17, p = .025) or "a great deal" (OR = 4.77, p = .028) of diagnostic value; perception that their department is "definitely" supportive (OR = 4.69, p = .040); "moderate" (OR = 4.75, p = .001) or "no" (OR = 7.51, p < .001) equipment limitations; and radiologist support greater than "extremely unsupportive or resistant" ("somewhat unsupportive" [OR = 5.74, p = .041], "neutral" [OR = 11.23, p = .002], "somewhat supportive" [OR = 13.92, p = .001], or "extremely supportive" [OR = 13.92, p = .001]). Barriers to AP view inclusion were geographic location in the southern U.S. census region (OR = 0.31, p = .007), being "significantly" influenced by coworker opinions (OR = 0.13, p = .018), and productivity tracking (OR = 0.21, p = .008). Environmental factors and organizational culture heavily influence AP view inclusion practices.

The Influence of Dopaminergic Medication on Regularity and Determinism of Gait and Balance in Parkinson’s Disease: A Pilot Analysis

Background/Objectives: Understanding how dual-tasking and Parkinson’s disease medication affect gait and balance regularity can provide valuable insights to patients, caregivers, and clinicians regarding frailty and fall risk. However, dual-task gait and balance studies in PD most often only employ linear measures to describe movement regularity. Some have used nonlinear techniques to analyze PD performances, but only in the on-medication state. Thus, it is unclear how the nonlinear aspects of gait or standing balance are affected by PD medication. This study aimed to assess how dopaminergic medication influenced the regularity and determinism of joint angle and anterior–posterior (AP) and medial–lateral (ML) center of pressure (COP) path time-series data while single- and dual-tasking in PD. Methods: Sixteen subjects with PD completed single- and dual-task gait and standing balance trials for 3 min off and on dopaminergic medication. Sample entropy and percent determinism were calculated for bilateral hip, knee, and shoulder joints, and the AP and ML COP path. Results: There were no relevant medication X task interactions for either the joint angles series or the balance series. Instead, the results supported independent effects of medication, dual-tasking, or standing with eyes closed. Balance task difficulty (i.e., eyes open vs. eyes closed) was detected by the nonlinear analyses, but the nonlinear measures yielded opposing results such that standing with eyes closed simultaneously yielded less regular and more deterministic signals. Conclusions: When juxtaposed with previous findings, these results suggest that medication-induced functional improvements in people with PD might be accompanied by a shift from lesser to greater signal consistency, and the effects of dual-tasking and standing with eyes closed were mixed. Future studies would benefit from including both linear and nonlinear measures to better describe gait and balance performance and signal complexity in people with PD.

Changes in mitral and tricuspid valve morphology after surgical repair of pectus excavatum

Abstract Background The effect of pectus excavatum (PE) on cardiac morphology and function has been reported previously. The right heart chamber size and cardiac output improved after the surgical correction of PE. However, the effect on the mitral and tricuspid valve has not been investigated. Purpose Our purpose was to investigate the morphological changes in the tricuspid and mitral valve after PE surgery. Methods We enrolled 25 patients who underwent Nuss surgery for PE repair. The inclusion criteria were 1) aged 15 years or older, 2) Haller Index of more than 5.0, and 3) transesophageal echocardiography (TEE) during PE surgery. We measured RV size and the sphericity index of tricuspid and mitral valve using 3D echocardiography before and after the elevation of the sternum. The sphericity index was calculated as the ratio of anterior-posterior (AP)/medial-lateral (ML) dimeter for the mitral valve (MV) and septal-lateral (SL) / AP dimeter for the tricuspid valve (TV). Results Mean age was 26±11 years, and 28% was female. The Haller index was 6.9 ± 2.8. All patients had normal left ventricular and right ventricular function evaluated with transthoracic echocardiography. The chamber diameter of the base and mid in RV increased after the elevation of the chest. The AP and SL dimeter were enlarged after the elevation of the chest in the TV, and the sphericity index of TV did not change. On the other hand, AP diameter increased but ML diameter was constant in the MV, and the sphericity index of MV increased after the elevation of the chest. Therefore, the annulus size was increased but the morphology was not changed in the TV. Unlike the TV, the morphology of MV annulus became close to circular from flat shape. In several patients, trivial mitral regurgitation was observed after elevation of chest, and possibly affected by the morphological change of the MV annulus. Conclusions The surgical repair for pectus excavatum effected not only right ventricular morphology but also on the tricuspid and mitral valve. The annulus change was different between the tricuspid and mitral valve.

Evaluation of a novel robotic testing method for stability and kinematics of total knee arthroplasty.

This work developed a novel preclinical test of total knee replacements (TKRs) in order to explain TKR instability linked to patient dissatisfaction. It was hypothesized that stability tests on the isolated moving prostheses would provide novel comparative data on the stability and kinematics among TKR designs. Three TKR designs, DePuy Synthes Attune MS, Stryker Triathlon and Zimmer Biomet Persona MC, were assessed using a robotic arm while flexing-extending 0-140°. Tests imposed 710 N body weight combined with three tibial loads: no anterior-posterior (AP) force, 90 N anterior or 90 N posterior force. Other load effects were minimized and the kinematics was recorded. Each implant was tested six times to investigate the repeatability of the method. Data were analysed using statistical parametric mapping with one-way analysis of variance (ANOVA). If significance was found (p < 0.05), post hoc t tests with Bonferroni correction were used to contrast groups. Significant differences were found throughout flexion-extension. Femoral rollback, AP stability, coupled internal-external rotation and AP position (roll-back) were all influenced by implant design. AP stability of the TKRs reduced with flexion reaching Attune 15 mm, Persona 13 mm and Triathlon 21 mm at 140° flexion. Tractive rolling significantly affected kinematics in the less congruent Triathlon design, with 6 mm different paths between flexion and extension motion (p < 0.05 across 5-100°). Paradoxical anterior femoral sliding in early flexion (0-40°) occurred in Persona and Triathlon designs. The novel testing technique provides, for the first time, comparative data on the inherent stability and kinematics of the TKR implants themselves across the arc of flexion-extension, independent of variables including soft tissue behaviour and surgical technique. The data show how much each prosthesis can contribute to the stability and motion of the implanted knee. Similar data from a wider range of designs will enable more informed decisions regarding implant design choice, aiming to reduce the prevalence of TKR instability in patients. Controlled laboratory study.

Kinematic Patterns of Different Loading Profiles Before and After Total Knee Arthroplasty: A Cadaveric Study

One of the major goals of total knee arthroplasty (TKA) is to restore the physiological function of the knee. In order to select the appropriate TKA design for a specific patient, it would be helpful to understand whether there is an association between passive knee kinematics intraoperatively and during complex activities, such as ascending stairs. Therefore, the primary objective of this study was to compare the anterior–posterior (AP) range of motion during simulated passive flexion and stair ascent at different conditions in the same knees using a six-degrees-of-freedom joint motion simulator, and secondary, to identify whether differences between TKA designs with and without a post-cam mechanism can be detected during both activities, and if one design is superior in recreating the AP translation of the native knee. It was shown that neither TKA design was superior in restoring the mean native AP translation, but that both CR/CS and PS TKA designs may be suitable to restore the individual native kinematic pattern. Moreover, it was shown that passive and complex loading scenarios do not result in exactly the same kinematic pattern, but lead to the same choice of implant design to restore the general kinematic behavior of the native individual knee.

Postural control among older adults with fear of falling and chronic low back pain

ObjectiveAltered Postural control could increase the risk of falling in older adults. Factors such as low back pain and fear of falling can be contributing factors to postural control instability. This study aimed to investigate the effect of chronic low back pain (CLBP) and fear of falling (FOF) on postural control of older adults.MethodForty-one older adults were included (27 LBP and 14 control). Among the participants, 22 people had high FOF, and 19 had low FOF based on Falls efficacy scale cut-off of ≥ 26. For postural control evaluation Center of pressure parameters (COP) of Standard deviation (Sd) of velocity, Sd of amplitude, path length and mean velocity in both Medial–lateral (ML) and Anterior–Posterior (AP) directions were measured. Mixed-model anova with two between group factor (Health status; with and without CLBP, and with high and low FES-I groups) and one within factor postural condition (four conditions with and without vision and Achill tendon vibration) was used.ResultNo significant interaction between groups (health status and FES-I) and group with condition (health status and condition or FES-I and condition) was observed for all COP parameters in both AP and ML direction. There was main effect of FES-I for all COP parameters in ML direction, with greater Sd of velocity, Sd of amplitude, path length and mean velocity in older adults with high FES-I compared to low FES-I in the ML direction.ConclusionHigh levels of FOF influenced static postural control in the ML direction. Therefore, paying attention to the lateral stability of older adults is of great importance.

Neural Correlates of Psychedelic, Sleep, and Sedated States Support Global Theories of Consciousness.

Understanding neural mechanisms of consciousness remains a challenging question in neuroscience. A central debate in the field concerns whether consciousness arises from global interactions that involve multiple brain regions or focal neural activity, such as in sensory cortex. Additionally, global theories diverge between the Global Neuronal Workspace (GNW) hypothesis, which emphasizes frontal and parietal areas, and the Integrated Information Theory (IIT), which focuses on information integration within posterior cortical regions. To disentangle the global vs. local and frontoparietal vs. posterior dilemmas, we measured global functional connectivity and local neural synchrony with functional magnetic resonance imaging (fMRI) data across a spectrum of conscious states in humans induced by psychedelics, sleep, and deep sedation. We found that psychedelic states are associated with increased global functional connectivity and decreased local neural synchrony. In contrast, non-REM sleep and deep sedation displayed the opposite pattern, suggesting that consciousness arises from global brain network interactions rather than localized activity. This mirror-image pattern between enhanced and diminished states was observed in both anterior-posterior (A-P) and posterior-posterior (P-P) brain regions but not within the anterior part of the brain alone. Moreover, anterior transmodal regions played a key role in A-P connectivity, while both posterior transmodal and posterior unimodal regions were critical for P-P connectivity. Overall, these findings provide empirical evidence supporting global theories of consciousness in relation to varying states of consciousness. They also bridge the gap between two prominent theories, GNW and IIT, by demonstrating how different theories can converge on shared neuronal mechanisms.

Comparing organ and effective dose of various CT localizer acquisition strategies: A Monte Carlo study.

CT examinations commonly start with the acquisition of one or two localizer radiographs (2D localizers). Recently, a manufacturer introduced the option to perform a heavily filtrated low-dose helical scan as a localizer acquisition. To compare the dose of one or two 2D localizer acquisitions to the dose of a 3D localizer acquisition, one cannot simply compare the CTDIs of the different acquisition techniques, because of the use of different geometries and spectra. To compare the organ and effective dose for various CT localizer acquisition techniques. A Geant4-based Monte Carlo simulation, replicating a clinical wide-area CT scanner was developed and validated. Various localizer acquisition strategies were simulated: Anterior-posterior (AP) alone, PA alone, combined AP+lateral (LAT), and PA+LAT 2D localizers, and an Ag-filtered 3D localizer acquisition. Validation was performed by measuring and simulating CTDI100 in both the periphery and the center of a CTDI phantom. The software was subsequently used to estimate organ and effective doses for localizers for chest, abdomen+pelvis, and the combined chest, abdomen, and pelvis exams. As representations of patients, eight ICRP computational phantoms (adult, 15-, 10-, and 5-year, both male and female) and five female and five male XCAT phantoms with various BMIs were used. The dose of the various strategies was compared to the current clinically-implemented AP+LAT localizers. CTDI100-measurements and simulations within the CTDI-phantom differs by a maximum of 8.1% and by an average of 0.9%. For chest, the average effective doses for AP, PA, AP+LAT, and the 3D localizer are 0.10, 0.07, 0.32, and 0.22 mSv, respectively. The organ dose to the breast varies the most across the various localizer strategies and is, on average, 0.17, 0.03, 0.44, and 0.33 mGy, in the same order. For abdomen, the average effective doses are 0.11, 0.07, 0.36, and 0.25 mSv for the AP, PA, AP+LAT and the 3D localizer, respectively. The organ dose to the stomach varies the most across the various localizers and is on average 0.14, 0.08, 0.58, and 0.30 mGy, in the same order. The PA-only localizer results in the lowest organ dose to the most radiosensitive organs and the lowest effective dose. For the chest exam, compared to AP+LAT, the PA+LAT results in a 7±2% effective dose reduction (mean±standard deviation), while the 3D localizer results in a 21±3% effective dose reduction. Using AP or PA only would result in 69±2% and 76±2% reduction, respectively. For the abdomen exam, also compared to AP+LAT, PA+LAT results in 6±2% effective dose reduction, while the 3D localizer results in a 20±5% reduction. Using AP or PA only would result in 69±5% and 76±4% reduction, respectively. Using a PA localizer results in a lower or equivalent organ dose in the most radiosensitive organs, and a lower effective dose compared to an AP localizer for both chest and abdomen+pelvis exams. Compared to a two-localizer strategy, the 3D localizer results in a lower effective dose in both the chest and abdomen+pelvis region.

Investigation of pelvic floor influence on prostate displacement in image-guided radiotherapy.

The uncertainty of target location during prostate cancer radiotherapy plays an important role in accurate dose delivery and radiation toxicity in adjacent organs. This study analyzed displacement correlations between the prostate and pelvic floor. We retrospectively analyzed registration results from 467 daily cone-beam computed tomography (CT) in 12 patients with prostate cancer who received radiation therapy. We analyzed prostate displacement and the pelvic floor relative to the pelvic bone's anatomy in the translational and rotational directions and identified statistical correlations. The systematic (Σ) and random (σ) displacements of the prostate in the three translational directions, anterior-posterior (AP), superior-inferior (SI), and right-left (RL), were 1.49 ± 1.45, 2.10 ± 1.40, and 0.24 ± 0.53 mm, respectively, and in the rotational directions of the pitch, roll, and yaw were 2.10 ± 2.02°, 0.42 ± 0.74°, and 0.42 ± 0.64°, respectively. The pelvic floor displacements were 2.37 ± 1.96, 2.71 ± 2.28, and 0.47 ± 0.84 mm in the AP, SI, and RL directions, respectively, and 0.93 ± 1.49°, 0.98 ± 1.28 °, and 0.87 ± 0.94° in the pitch, roll, and yaw directions, respectively. Additionally, there were statistically significant correlations between the displacement of the prostate and pelvic floor in the AP and SI directions, with correlation coefficients (r) of 0.74 (p < 0.001) and 0.69 (p < 0.001), respectively. The movement of the pelvic floor may be an important factor that causes prostate displacement, affecting the accuracy of radiotherapy. Therefore, it is necessary to take appropriate measures to ensure that the pelvic floor muscle tension is as consistent as possible in the treatment' CT scan and daily treatment.

Vendor-Specific Correction Software for Apparent Diffusion Coefficient Bias Due to Gradient Nonlinearity in Breast Diffusion-Weighted Imaging Using Ice-Water Phantom.

This study aimed to evaluate a vendor-specific correction software for apparent diffusion coefficient (ADC) bias due to gradient nonlinearity in breast diffusion-weighted magnetic resonance imaging using an ice-water phantom. The phantom consists of 5 plastic tubes with a length of 100 mm and a diameter of 15 mm, filled with distilled water and immersed in an ice-water bath. Diffusion-weighted images were acquired by echo-planar imaging sequence on a 3.0-T scanner. ADC maps with and without correction were calculated using 4 b -values (0, 100, 600, and 800 s/mm 2 ). The mean ADCs were measured using a rectangular profile with 5 × 40 pixels in the anterior-posterior (AP) and a square region of interest with 5 × 5 pixels in the right-left (RL) and superior-inferior (SI) directions on the ADC map. ADC was compared with and without correction using a paired t test. Additionally, ADC of the ice-water phantom was measured at the magnet isocenter. ADC increased in the AP and RL directions and decreased in the SI direction with increasing distance from the isocenter before correction. After the correction, ADC at the off-center positions in the AP, RL, and SI directions was reduced to within 5% of the expected value. There were significant differences in the ADC at the off-center positions without and with correction ( P < 0.001); however, ADC at the magnet isocenter did not vary after correction (1.08 ± 0.02 × 10 -3 mm 2 /s). The vendor-specific software corrected the ADC bias due to gradient nonlinearity at the off-center positions in the AP, RL, and SI directions. Therefore, the software will contribute to the accurate ADC assessment in breast DWI.

Increased hindbrain motion in Chiari I malformation patients measured through 3D amplified MRI (3D aMRI)

Chiari Malformation type 1 (CM-I) is a neurological disorder characterized by morphological defects including excessive cerebellar tonsillar ectopia and associated manifestations. We used 3D amplified MRI on a cohort of healthy and CM-I subjects to investigate the brain’s intrinsic motion, its association with the morphology and patient’s symptomatology, and surgical outcomes. We observed that the regional brain motion in CM-I was significantly higher than that of the healthy subjects, with anterior-posterior (AP) and superior-inferior (SI) displacements in cerebellar tonsils and medulla having the highest differences between the healthy and CM-I (∼45%–∼73% increased motion in the CM-I group). Interestingly, we found the ratio of neural tissue in the foramen magnum to be directly correlated with the SI tonsillar motion (r=0.58). Tonsillar herniation was directly correlated with the AP motion of the tonsils (r=0.61), and AP and medial-lateral (ML) motions of the medulla (r=0.66, and r=0.57). Subjects with higher tonsillar ML motion prior to surgery showed improved outcome (p=0.03, and AUC=0.95). Although we did not observe a significant correlation between the brains motion and morphometrics on the CM-I symptoms (perhaps due to our small sample size), illustrative cases increase our hope for the development of a future tool based on brain biomechanics.

Strategies for unplanned gait termination at comfortable and fast walking speeds in children with cerebral palsy

Collision avoidance while walking is necessary for safe living, and faster walking speeds tend to increase collision risk. However, gait termination strategies for patients with cerebral palsy (CP), from comfortable to faster speed, remain unexplored. This study aimed to analyze these strategies in children with CP compared to typically developing (TD) children at two different speeds. Study participants included 10 children with CP (mean age, 12.5; five females; mean height, 147.8 cm; mean weight, 41.7 kg) and 10 TD children (mean age, 11.4; nine females; mean height, 142.0 cm; mean weight, 38.1 kg). Effects of walking speed on spatial, force, and temporal parameters were assessed at 100 % (WS1) and 125 % (WS2) speeds of comfortable walking. The TD group exerted a more pronounced braking force at the first step after the stop line appeared on the floor until the contralateral step at both WS1 (P = 0.006) and WS2 (P = 0.019); however, the CP group exerted a more potent force after the second step (WS1: P = 0.026, WS2: P = 0.023) in the anterior-posterior (AP) direction. Additionally, an increase in the center of mass (COM)-center of pressure (COP) divergence in the AP direction (P = 0.032), which decreased in the mediolateral (ML) direction (P = 0.036) at faster walking speeds, influenced the kinetic characteristics of the CP group from WS1 to WS2. The complex adaptations, such as unique braking forces and changes in the COM-COP divergence, suggest that gait interventions should consider the distinctive forces and adopt dynamic balancing strategies to avoid collisions during walking.

A comparison of three methods for establishing an ACL reference length in vivo

As anterior cruciate ligament (ACL) injuries are highly prevalent among active individuals, it is vital to better understand the loading conditions which lead to injury. One method for doing so is through measurement of dynamic, in vivo ACL strain. To measure strain, it is necessary to normalize elongation of the ACL to a ‘reference length’ which corresponds to the point at which the ligament transitions from being unloaded to carrying tension. The purpose of this study was to compare the length of the ACL in three different positions to evaluate their utility for establishing a reference (or zero-strain) length of the ACL.ACL reference length was determined using three different methods for each of ten healthy participants. Using magnetic resonance and biplanar radiographic imaging techniques, we measured the length of the ACL during supine resting, quiet standing, and anterior/posterior (AP) drawer testing. During the AP drawer testing, the slack-taut transition point was defined as the inflection point of the AP translation vs ACL elongation curve.There was good consistency between the three ACL length measurements (ICC=0.80). Differences in mean ACL length between the three methods were within 1 mm.While determining the precise zero-strain length of the ACL in vivo remains a challenge, the reference positions utilized in this study produce consistent measurements of ACL length. These findings are important because reliable measurements of in vivo ACL strain have the potential to serve as indicators of propensity for injury.

Novel arthrometer for quantitative clinical examination of the knee in three planes: Safety, reliability, minimum detectable changes, and side-to-side differences in healthy subjects

Physical examination of the knee joint is used to diagnose the type and severity of knee ligament injury; however, these exams are qualitative and subjective. To perform common physical examinations, we developed an arthrometer which quantitatively measures the load–displacement response in anterior-posterior (AP) translation, internal-external rotation (IER) and varus-valgus (VV) rotation. Here we describe safety, reliability, minimum detectable changes (MDCs), and absolute side-to-side differences in twenty young, healthy subjects (ten male, ten female, mean age: 28 ± 6 years). The arthrometer consists of an instrumented mechanical linkage, a force-moment sensor, and software for real-time visualization and recording of the load–displacement responses. During testing, the subject sits reclined in a chair with their knee fixed at 30° of flexion. Two examiners tested both knees of each subject twice to assess reliability via intraclass correlation coefficients (ICC). All subjects completed the test protocol with minimal pain and stated that they would volunteer to be tested again. Each knee required on average five minutes to test. All intra-test reliabilities were excellent (≥0.91). Intra-examiner reliabilities ranged from good to excellent (0.62–0.89), and inter-examiner reliabilities were good to excellent (≥0.72). MDCs for repeat measures were ≤ 4.5 mm, 4.6°, and 2.3° for AP, IER, and VV, respectively. The absolute side-to-side differences for this cohort averaged 3.8 mm in AP, 5.5° in IER, and 2.2° in VV. Our arthrometer was safe, testing was time-efficient, and MDCs in our cohort of healthy subjects support utilization of this device for clinical research.

Comparison of Radiation Doses for Different Techniques in Fluoroscopy-Guided Lumbar Facet Medial Branch Blocks: A Retrospective Cohort Study.

Chronic lumbar facet pain is commonly treated with fluoroscopy-guided facet medial branch blocks (FMBBs). However, the associated radiation exposure of both patients and clinicians is a growing concern. This study aimed to compare radiation doses and fluoroscopy times between two techniques, i.e., oblique and posterior-anterior (PA) fluoroscopic approaches, while also examining the impact of physician experience on these metrics. A retrospective analysis was conducted on 180 patients treated at Mersin University Hospital Pain Clinic between January and July 2024. Patients were divided into two groups: 90 received the oblique technique (Group O) and 90 received the AP technique (Group A). Radiation dose and fluoroscopy time data were collected for each patient. The AP technique was associated with significantly lower radiation doses (mean 66 mGy) and shorter fluoroscopy times (mean 28 s) compared to the oblique technique (mean radiation dose of 109 mGy and fluoroscopy time of 46 s) (p < 0.001). Physician experience also influenced these outcomes, with more experienced physicians consistently using less radiation. The AP technique should be considered for FMBBs, as it reduces radiation exposure while maintaining procedural efficiency, highlighting the importance of experience in optimizing outcomes.

An Insert Goniometer Can Help Select the Optimal Insert Thickness When Performing Kinematically Aligned Total Knee Arthroplasty with a Medial 1:1 Ball-in-Socket and Lateral Flat Surface Insert and Posterior Cruciate Ligament Retention.

Current surgical practices in total knee arthroplasty (TKA) have advanced and include significant changes and improvements in alignment philosophies, femorotibial implant conformities, and ligament management to replicate in vivo knee kinematics. While corrective measures have emphasized sagittal plane alignment to restore normal flexion-extension (F-E) motion and coronal plane ligament balance, internal-external (I-E) rotation kinematics in the axial plane have been largely neglected. Recent in vivo evidence indicates that the combination of factors necessary to closely restore native tibial rotation as the knee flexes and extends is kinematic alignment (KA), which resurfaces the patient's pre-arthritic knee without releasing ligaments, an insert with medial 1:1 ball-in-socket conformity and a lateral flat surface, and posterior cruciate ligament (PCL) retention. However, the inherent anterior-posterior (A-P) stability provided by the medial 1:1 ball-in-socket limits the surgeon's ability to select the correct insert thickness using manual laxity testing. Accordingly, this review presents the design and validation of an instrument called an insert goniometer that measures I-E tibial rotation for inserts that differ in thickness by 1 mm and uses rotation limits at extension and 90° flexion to select the optimal insert thickness. The optimal thickness is the one that provides the greatest external tibial orientation in extension and internal tibial orientation at 90° flexion without lift-off of the insert.

Significant systematic bias of alpha angles measured on MRI compared to various radiographic views in patients with femoroacetabular impingement syndrome.

The aim of this study was to assess the inter-rater reproducibility and inter-method comparability of hip alpha angle measurements on magnetic resonance imaging (MRI)/magnetic resonance arthrography (MRA) and plain radiographs in patients with femoroacetabular impingement syndrome (FAIS). A cross-sectional study of patients who were diagnosed with symptomatic FAIS underwent preoperative MRI/MRA with axial oblique and/or radial plane imagingand had preoperative radiographs with anterior-posterior (AP), 45° Dunnand 90° Dunn views. Alpha angle measurements were performed independently by two musculoskeletal radiologists. Inter-rater reproducibility and inter-method comparability between MRI/MRA images and radiographic views were assessed using the intraclass correlation coefficient (ICC) with 95% confidence interval (CI). Ninety-seven patients were included of whom 93 (95.8%) received axial oblique plane images and 54 (55.6%) had radial plane MRI/MRA images. Inter-rater reproducibility was excellent (ICC > 0.9) for all planes on MRI/MRA and radiographs. MRI/MRA axial oblique images had poor (ICC 0.39, 95% CI [0.09, 0.59]), moderate (ICC 0.57, 95% CI [0.18, 0.75])and moderate (ICC 0.64, 95% CI [0.20, 0.81]) comparability with AP, 45° Dunnand 90° Dunn, respectively. MRI/MRA radial plane images had equivocal (0 included in all CIs) comparability with AP (ICC 0.66), 45° Dunn (ICC 0.35)and 90° Dunn (ICC 0.14) radiographs. On average, alpha angle measurements were significantly higher with radial images and lower with axial oblique images, when compared to all radiographic views (p < 0.05), except axial oblique versus 45° Dunn views, where angles measured on axial oblique were significantly larger. Alpha angle measurements taken on axial oblique MRI/MRA images show moderate comparability to radiographic 45° Dunnand 90° Dunn views despite negative bias to measurements taken on radiographic AP and 45° Dunn view. Larger alpha angles were appreciated on MRI/MRA radial and axial oblique views compared to radiographic views supporting the inclusion of MRI/MRA alpha angle measurements to properly identify deformity. Level II.

Initial Defibrillator Pad Position and Outcomes for Shockable Out-of-Hospital Cardiac Arrest

Ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) are the most treatable causes of out-of-hospital cardiac arrest (OHCA). Yet, it remains unknown if defibrillator pad position, placement in the anterior-posterior (AP) or anterior-lateral (AL) locations, impacts patient outcomes in VF or pVT OHCA. To determine the association between initial defibrillator pad placement position and OHCA outcomes for patients presenting with VF or pVT. This prospective cohort study included patients with OHCA and VF or pVT treated by a single North American emergency medical services (EMS) agency from July 1, 2019, through June 30, 2023. The study included patients with OHCA treated by a large suburban fire-based EMS agency that covers a population of 550 000. Consecutive patients with an initial EMS-assessed rhythm of VF or pVT receiving EMS defibrillation were included. Pediatric patients (younger than 18 years), interfacility transfers, arrests of obvious traumatic etiology, and patients with preexisting do-not-resuscitate status were excluded. AP or AL pad placement. Return of spontaneous circulation (ROSC) at any time with secondary outcomes of pulses present at emergency department (ED) arrival, survival to hospital admission, survival to hospital discharge, and functional survival at hospital discharge (cerebral performance category score of 2 or less). Measures included adjusted odds ratios (aOR), multivariable logistic regressions, and Fine-Gray competing risks regression. A total of 255 patients with OHCA were included (median [IQR] age, 66 [55-74] years; 63 females [24.7%]), with initial pad positioning documented as either AP (158 patients [62.0%]; median [IQR] age, 65 [54-74] years; 37 females [23.4%]) or AL (97 patients [38.0%]; median [IQR] age, 66 [57-74] years; 26 females [26.8%]). Patients with AP placement had higher adjusted odds ratio (aOR) of ROSC at any time (aOR, 2.64 [95% CI, 1.50-4.65]), but not significantly different odds of pulses present at ED arrival (1.34 [95% CI, 0.78-2.30]), survival to hospital admission (1.41 [0.82-2.43]), survival to hospital discharge (1.55 [95% CI, 0.83-2.90]), or functional survival at hospital discharge (1.86 [95% CI, 0.98-3.51]). Competing risk analysis found significantly greater cumulative incidence of ROSC among those at risk with initial AP placement compared with AL (subdistribution hazard ratio, 1.81 [95% CI, 1.23-2.67]; P = .003). In this cohort study of patients with OHCA and VF or pVT, AP defibrillator pad placement was associated with higher ROSC compared with AL placement.