Effects of different PCOS phenotypes on placental three-dimensional power Doppler indices and placental volume during the first trimester.

INTRODUCTION: The aim of the present study was to evaluate the effects of different polycystic ovary syndrome (PCOS) phenotypes using first-trimester placental three-dimensional power Doppler indices and placental volume. METHODS: In this prospective case-control study, 170 pregnant women who met the inclusion criteria were divided into five groups according to PCOS phenotype: non-PCOS control (n = 34), PCOS phenotype A (n = 34), PCOS phenotype B (n = 34), PCOS phenotype C (n = 34), and PCOS phenotype D (n = 34). The primary outcomes determined in the present study were the differences in placental volume and placental flow index (FI), vascularization flow index (VFI), vascularization index (VI), and uterine artery pulsatility index (PI) betweenthe PCOS groups and control group. RESULTS: The mean placental volume and VI were significantly decreased in the phenotype A, B, and C groups compared to the control group and PCOS phenotype D group. The mean FI and VFI were significantly decreased in the phenotype A and B groups compared to the control group and PCOS phenotype C and D groups. The mean testosterone, dehydroepiandrostenedione, sex-hormone binding globulin, free androgen index, and insulin resistance levels were significantly increased in the phenotype A, B, and C groups compared to the control group and PCOS phenotype D group. DISCUSION: The results indicated that placental volume and placental vascular Doppler indices in the first trimester were more adversely affected in the PCOS A and B phenotypes than other PCOS phenotypes.

Role of the brain-sparing effect on retinopathy of prematurity in newborns with fetal growth restriction.

INTRODUCTION: This study aimed to investigate the role of the brain-sparing effect (BSE) on retinopathy of prematurity (ROP) in fetal growth restriction (FGR). METHODS: In this retrospective study, 127 pregnant women were divided into two groups considering the cerebroplacental ratio (CPR): FGR with abnormal CPR group (n = 74) and the appropriate for gestational age with normal Doppler group (n = 53). CPR was computed using the pulsatility index (PI) and resistance index (RI) to quantitate the waveforms [middle cerebral artery (MCA) PI/umbilical artery (UA) PI and MCA RI/UA RI: a result <1 was taken into account as abnormal]. ROP screening results of newborns were recorded from electronic files. RESULTS: After adjusting for co-variants, BSE was not related to ROP (adjusted odds ratio [aOR], 1.06; 95% confidence interval [CI], 0.23-4.95). Gestational age at delivery <30 weeks (aOR, 2.55; 95% CI, 1.04-6.93) and birth weight <1500 g (aOR, 5.15; 95% CI, 1.15-25.2) were independently associated with ROP. Preeclampsia, emergency cesarean section birth, or 48 h completion after the first steroid administration were not associated with ROP. CONCLUSIONS: Gestational age at delivery <30 weeks and birth weight <1500 g are independent risk factors for ROP in FGR whereas the BSE is not a risk factor.

Management of patellar instability in skeletally immature patients.

Surgical intervention is the treatment of choice for recurrent lateral patellar instability. Surgery should be considered for first time lateral patella dislocations with osteochondral fractures or underlying anatomical risk factors. Primary repair and nonanatomical imbrications/reconstructions have fallen out of favor due to abnormal biomechanics and high rates of recurrence. Anatomical reconstruction of the MPFL using a variety of auto and allograft tissues have yielded good outcomes and low redislocation rates. Physeal sparing MPFL reconstruction techniques under radiological control are safe and do not cause growth disturbance. Allografts may be indicated for hyperlax patients. Although no clear cutoff points exist, correction of valgus and excessive femoral anteversion should be considered when indicated. Osteochondral and chondral injuries are common and should be addressed during surgery for instability.

Volar buttress plate fixation: An effective and reliable option for Bennett's fractures.

OBJECTIVES: This study aimed to demonstrate the volar plate fixation technique for fixing Bennett's fractures due to its buttress effect. PATIENTS AND METHODS: The retrospective study included 10 patients (8 males, 2 females; mean age: 35.9±11.56 years; range, 17 to 51 years) who were treated using the volar plate fixation technique between January 2018 and August 2022. The postoperative functional scores of the patients were evaluated using the Q-DASH (Quick Disabilities of the Arm, Shoulder, and Hand) score, and their pain status was evaluated with the Visual Analog Scale (VAS). We also assessed fracture union and development of complications. We assessed opposition according to Kapandji grade and abduction of the thumb. RESULTS: The mean follow-up time was 16.6±2.91 (range, 12 to 21) months. The technique was performed on the right extremity in eight patients and on the left extremity in two patients. All patients were right-hand dominant. The VAS score was 1 in two cases and 0 in the other cases. The mean Q-DASH score was 1.36±2.44. The mean pinch strength was 6.4±0.89 kg, and the mean grasp strength was 18.8±3.52 kg on the injured side. The mean Kapandji grade of opposition was 9.3±0.82, while the mean abduction degree was 37.4±2.01. CONCLUSION: Based on the early results of this technique, we conclude that volar plate fixation for Bennett's fractures is reliable and allows for early motion, providing anatomical and stable joint reduction, and it does not have implant complications such as hardware irritation. However, fixation of small fragments may be particularly challenging.

Comparison of conventional and robotic knee arthroplasty results: A retrospective observational study.

OBJECTIVE: This study aimed to determine whether a standard anesthetic protocol consisting of combined spinal epidural anesthesia (CSEA) in conjunction with controlled hypotensive anesthesia (CHA), which was used for conventional total knee arthroplasty (cTKA), could provide equally effective anesthetic conditions for robotic total knee arthroplasty (rTKA). METHODS: Data were collected from the medical records of 113 patients (median age=67 years; age range=55-84) who underwent elective unilateral cTKA (n=52) or rTKA (n=61) without a tourniquet from 2021 to 2023. The primary outcome measure was the rate of patients whose anesthetic method did not provide adequate motor and sensory block during the surgery and had to be converted to general anesthesia. The secondary outcome measure was to compare perioperative variables, including pain scores, analgesic consumption, blood loss, transfusions, and complications. RESULTS: In 6 patients (11.5%) in group rTKA, it was required to convert CSEA to general anesthesia at 160-180 minutes due to the pain at the operative knee and/or to the movement of the operative leg during surgery compared to none / zero in group cTKA (P=.008). Motor and sensory blocks terminated earlier than the total surgery time in those patients. Mean total surgery time was significantly higher in group rTKA than in group cTKA (151.25 ± 24.51 (120-240) minutes vs. 116.72 ± 4.99 (105-125) minutes, P < .001). Total surgery times tended to decrease gradually in group rTKA after the 11th case, indicating a learning curve for surgical performance. Conversion to general anesthesia was required only in 1 patient after the 11th case compared to the previous 5 patients. Mean pain scores and rescue analgesic consumption were higher in group rTKA at postoperative 0 hour and between 0 and 4 hours (P < .05) but similar at the following time points (P > .05). Blood loss, transfusion, and complication rates were similar (P > .05). Hospital discharge times were higher in group rTKA (P < .05). CONCLUSION: Although our standard CSEA protocol failed due to the regression of motor and sensory block during surgery in 11.5% of patients in rTKA, the CSEA technique combined with controlled hypotensive anesthesia provided similar anesthetic conditions in the remaining patients in group rTKA as in group cTKA. The CSEA may be considered an effective and safe anesthetic method for rTKA if interventions are applied to extend the duration of the CSEA for this novel surgical technique. LEVEL OF EVIDENCE: Level III, Therapeutic Study.

Characteristics and Research Trends of the 100 Most-Cited Flatfoot Articles.

BACKGROUND: Bibliometric studies in the field of orthopedics have increased because of the large volume of the available literature that prevents understanding the general status of the related field. This study aimed to identify and analyze the 100 most-cited articles related to flatfoot to reveal their characteristics and research trends. METHODS: Available literature on the Web of Science database until the end of 2020 were analyzed, and the 100 most-cited articles were determined. The characteristics of articles including publication year, authors, institutions, country, journal, number of pages, number of references, study design, level of evidence, main topic, age group, the specialty of the first author, and availability of funding were extracted and statistically analyzed for any association with the number of citations or citation density. RESULTS: The average citation number was 63.1 ± 43.8 (range, 30-278). The average citation density was 3.4 ± 1.8 (range, 0.8-12.6). The United States was the leading country with 65 articles, followed by Taiwan and the United Kingdom with five articles from each. Twenty-six papers had Level III evidence and 36 papers had Level IV evidence. Only three studies had Level I evidence and three had Level II evidence. The majority of articles (43 papers) were published in Foot & Ankle International. Citation density was positively correlated with publication year (P < .001) and the number of references (P = .004). CONCLUSIONS: The available data provide general characteristics of the 100 most influential papers about flatfoot. The vast majority of papers had a low level of evidence, indicating the need for higher quality research.

Generalized Tensor Summation Compressive Sensing Network (GTSNET): An Easy to Learn Compressive Sensing Operation.

The efforts in compressive sensing (CS) literature can be divided into two groups: finding a measurement matrix that preserves the compressed information at its maximum level, and finding a robust reconstruction algorithm. In the traditional CS setup, the measurement matrices are selected as random matrices, and optimization-based iterative solutions are used to recover the signals. Using random matrices when handling large or multi-dimensional signals is cumbersome especially when it comes to iterative optimizations. Recent deep learning-based solutions increase reconstruction accuracy while speeding up recovery, but jointly learning the whole measurement matrix remains challenging. For this reason, state-of-the-art deep learning CS solutions such as convolutional compressive sensing network (CSNET) use block-wise CS schemes to facilitate learning. In this work, we introduce a separable multi-linear learning of the CS matrix by representing the measurement signal as the summation of the arbitrary number of tensors. As compared to block-wise CS, tensorial learning eases blocking artifacts and improves performance, especially at low measurement rates (MRs), such as [Formula: see text]. The software implementation of the proposed network is publicly shared at https://github.com/mehmetyamac/GTSNET.

Clinical differences between nasogastric tube and Hunter's rod for staged Zone II flexor tendon reconstruction.

OBJECTIVES: This study aims to compare the outcomes of two-stage flexor tendon reconstruction in Zone II of the hand and to evaluate the results of a nasogastric tube as a potential alternative to Hunter's rod. PATIENTS AND METHODS: Between November 2012 and January 2022, a total of 45 patients (26 males, 19 females; median age: 31 years; range, 12 to 61 years) who underwent two-stage flexor tendon reconstruction were retrospectively analyzed. Of the patients 24 underwent nasogastric tube reconstruction (NT group) and 21 underwent Hunter's rod reconstruction (HR group). Patients' demographic and clinical characteristics, the number of surgeries, the occurrence of complications, the presence of infection during the procedure, and the range of motion of the finger joints at the final follow-up examination were recorded. The assessment of the cases was conducted using the total active motion system. RESULTS: Twenty-four digits underwent two-stage flexor tendon reconstruction with the nasogastric tube. Among these, three index fingers, nine middle fingers, seven ring fingers, and five little fingers were operated. Twenty-one digits underwent two-stage flexor tendon reconstruction using Hunter's rod. Among these, two index fingers, eight middle fingers, six ring fingers, and five little fingers were operated. In the NT group, excellent results were observed in 58.3% (14 digits), good results in 25% (six digits), fair results in 8.3% (two digits), and poor results in 8.3% (two digits). In the HR group, excellent results were seen in 57.1% (12 digits), good results in 33.3% (seven digits), fair results in 4.7% (one digit), and poor results in 4.7% (one digit). CONCLUSION: The utilization of a nasogastric tube offers a convenient and cost-effective option to Hunter's rod in the two-stage flexor tendon reconstruction, leading to favorable outcomes characterized by high rates of excellence and improvement, while effectively minimizing the occurrence of complications.

Genome wide association study of genes controlling resistance to Didymella rabiei Pathotype IV through genotyping by sequencing in chickpeas (Cicer arietinum).

Ascochyta blight (AB) is a major disease in chickpeas (Cicer arietinum L.) that can cause a yield loss of up to 100%. Chickpea germplasm collections at the center of origin offer great potential to discover novel sources of resistance to pests and diseases. Herein, 189 Cicer arietinum samples were genotyped via genotyping by sequencing. This chickpea collection was phenotyped for resistance to an aggressive Turkish Didymella rabiei Pathotype IV isolate. Genome-wide association studies based on different models revealed 19 single nucleotide polymorphism (SNP) associations on chromosomes 1, 2, 3, 4, 7, and 8. Although eight of these SNPs have been previously reported, to the best of our knowledge, the remaining ten were associated with AB resistance for the first time. The regions identified in this study can be addressed in future studies to reveal the genetic mechanism underlying AB resistance and can also be utilized in chickpea breeding programs to improve AB resistance in new chickpea varieties.

Enhanced injectability of aqueous ß-tricalcium phosphate suspensions through PAA incorporation, gelling and preshearing.

The major shortcoming of aqueous calcium phosphate suspensions used in biomedical applications is their unstable flow during delivery by mechanical means. In this study, microstructural changes and the resulting flow instabilities of aqueous ß-TCP suspensions are demonstrated under both pressure-induced and drag-induced flow regimes and then remedied with the incorporation and subsequent gelling and preshearing of Carbopol 940, a biocompatible hydrogel. Mixing and dispersion of calcium phosphate particles into the hydrogel matrix was not efficient under simple agitation conditions. Swelling of the polymer chains was induced at approximately pH = 9.0 by water and particle intrusion within the opened-up coil structure due to deprotonation of the carboxylic acid groups by NaOH. As a result the composite material underwent a rapid viscoplastic transition into a doughy state which was not amenable to further processing without preshearing. Manual kneading converted the material into viscous state and enhanced the flow behavior significantly. Preshearing and probing the microstructure by mechanical spectrometer revealed multiple microstructural mechanisms responsible for the observed stable flow behavior, including improved dispersion of the particles, attrition of the polymeric network into microgel domains, enhanced adhesion and lubrication between the solid and liquid phase, crosslinking of the polymeric network. The net effect of these probable mechanisms was stiffening of the composite matrix, mobilization of solid particles and a marked enhancement in the stability of pressure-induced flow. The resistance of the material to liquid phase migration and its ability to undergo wall-slip and relax under stress were confirmed by simultaneous capillary rheometry and thermogravimetric analyses. The processing method enables improvements in the delivery of this composite material for injection and direct ink writing of scaffolds.

Third-trimester persistent maternal hypotension effects on late-onset small for gestational age and adverse perinatal outcomes.

INTRODUCTION: The purpose of the current study was to examine whether third-trimester persistent maternal hypotension is related to small for gestational age (SGA) and adverse perinatal outcomes. METHODS: In this large retrospective cohort study, 6560 pregnant women were enrolled and divided into two groups according to maternal tension status: a normotensive group (n: 6290) and a persistent maternal hypotensive group (n: 270). Persistent maternal hypotension was defined as an SBP <100 mmHg and/or DBP <60 mmHg at three antenatal visits: visit 1 (260/7-296/7 gestation weeks), visit 2 (300/7-336/7 gestation weeks), and visit 3 (340/7-366/7 gestation weeks). Following the Delphi consensus criteria, a fetal growth restriction diagnosis was employed. The presence of an SGA neonate was the primary outcome of the study. SGA was defined as fetal abdominal circumference below the 10th percentile or fetal birth weight below the 10th percentile in the absence of abnormal Doppler findings. The secondary outcomes were defined as the presence of other adverse perinatal outcomes. RESULTS: The baseline characteristics of the study population were similar. We found that SGA rates were 6.3% in the control group and 7.0% in the persistent maternal hypotension group, which were statistically similar. In the present study, the secondary outcomes which prematurity, low 5-min Apgar score, and NICU admission were similarly between groups. DISCUSSION: Our results indicate that third-trimester persistent hypotension is not associated with SGA neonates or adverse perinatal outcomes. Hence, it can be concluded that third-trimester persistent hypotension is a physiological phenomenon during pregnancy that should not cause anxiety in mothers.

Cortices of Fibula and Tibia Can Provide Landmarks for Accurate Syndesmosis Fixation Angle: Computed Tomography Validation of Angle Bisector Method.

Anatomic syndesmosis reduction is necessary to restore ankle biomechanics and prevent poor clinical outcomes, but malreduction can be encountered frequently since the ideal fixation angle varies between patients and fixation levels. This study aimed to validate the angle bisector method to reveal whether it provides an accurate syndesmotic fixation angle that is patient- and level-specific. Lower extremity CT angiography of 50 consecutive patients (25 male, 25 female) without evident ankle pathology were evaluated. The average age was 52.8 (±18, range: 18-75). Lines tangent to anterior and posterior cortices of tibia and fibula were drawn in the axial plane at both 2 cm and 3.5 cm above the ankle joint line. Bisection of the angle formed between these lines was drawn and its relationship with the centroidal axis, which is proposed to be the ideal syndesmotic axis, was evaluated. The angle between the bisector line & the centroidal axis and the distance between their most lateral intersections with the fibula were calculated. The measurements were made by 3 blinded observers. Intra- and interobserver reliability analyses were conducted. The average centroidal axis-bisector angle was 2.1° ± 2.1° at 2 cm and 0.6° ± 1.3° at 3.5 cm level. The average distance to the actual syndesmosis entry point was 1.0 ± 0.9 mm at 2 cm and 0.4 ± 0.4 mm at 3.5 cm level. The values didn't show any significant difference according to gender. Intra- and interobserver reliability analysis showed excellent correlation in all parameters (interclass correlation coefficient > 0.90). Angle bisector method was found strongly reliable providing accurate direction for syndesmotic axis. It can provide a patient- and level-specific angle for the application of syndesmotic implants without increasing the fluoroscopy exposure. Its use can have a broad impact on functional outcomes of ankle injuries by decreasing the malreduction rates. Further cadaveric validation and safety studies should be conducted for possible clinical usage.

Fetal Diaphragmatic Excursion Is Decreased in Hospitalized Pregnant Women Infected with COVID-19 during the Second and Third Trimesters.

OBJECTIVE: In the present study, we aimed to evaluate coronavirus disease 2019 (COVID-19) infection effects on fetal diaphragm thickness and diaphragmatic excursion, which together show the quality of diaphragmatic contractions. STUDY DESIGN: One hundred and ninety-two pregnant women were included in this prospective case-control study. Patients were divided into four groups according to their COVID-19 infection history in their second or third trimester: hospitalized COVID-19-infected pregnant women group (n = 48), outpatient COVID-19-infected pregnant women group (n = 48), common cold (COVID-19 polymerase chain reaction negative) pregnant women group (n = 48), and noninfected healthy controls (n = 48). The number of patients was determined by power analysis following the pilot study. All participants underwent an ultrasound examination to determine fetal diaphragm parameters at 32 to 37 weeks of gestation. RESULTS: Demographic characteristics were similar among the four groups. The gestational age at ultrasound examination and gestational age at delivery were similar among the groups. Neonatal intensive care unit (NICU) admission rate was significantly higher in the hospitalized COVID-19-infected pregnant women group than the other groups. The fetal diaphragm thickness during inspiration and expiration, and fetal costophrenic angles at inspiration and expiration were similar among the groups. Fetal diaphragmatic excursion was significantly decreased in the hospitalized COVID-19-infected pregnant women group compared with the other groups. CONCLUSION: Our results indicated that moderate maternal COVID-19 infection decreased fetal diaphragmatic excursion, and ultrasonographic evaluation of fetal diaphragmatic excursion before delivery can provide critical information to predict whether infants will require NICU admission. KEY POINTS: · Diaphragm ultrasound as a new technique for characterizing the diaphragm's structure and function.. · Fetal diaphragmatic excursion is decreased in the presence of moderate COVID-19 infection.. · Ultrasonographic evaluation of fetal diaphragmatic excursion provides critical information to predict NICU admission..

How understandable are the patient education materials about flat foot on the Internet for parents?

Flat foot is a common reason for parents to visit orthopedic clinics. As the Internet has become an easy-search platform, parents often seek online educational materials before seeking out a professional. The aim of this study was to investigate the quality, readability, and understandability of such online materials for parents. An Internet search was performed for "flat foot" and "pes planus" using the Google search engine. The readability was evaluated using 6 different grading systems: Flesch Reading Ease Score, Flesch-Kincaid Grade Level, Simple Measure of Gobbledygook, Fry Readability score, Gunning Fog Index tests, and Automated Readability Index. The Patient Education Materials Assessment Tool test was used to assess the understandability. For quality assessment, the Journal of American Medical Association benchmark criteria and Health on the Net code were applied. One hundred nine websites were included and evaluated for readability, understandability, and quality. The mean readability grade for all websites was 10.5 ±â€…2.0. The mean Gunning Fog Index tests and Flesch-Kincaid Grade Level scores for all websites were 12.4 ±â€…2.2 and 9.7 ±â€…2.1 sequentially. The mean Coleman-Liau index score was 10.0 ±â€…1.5, and the average Fry Readability score was 9.9 ±â€…2.0. The automated readability index for all websites was 10.3 ±â€…2.5. The average Flesch Reading Ease score for all educational materials was 59.3 ±â€…10.1. The average Patient Education Materials Assessment Tool score for all educational materials was 81% (range, 70-87%). The mean Journal of American Medical Association benchmark criterion for all websites was 1.0, with a range from 1.0 and 2.0. Eighteen (16.5%) websites had Health on the Net certificates. Readability, understandability, and quality of patient education materials about flat feet on the Internet vary and are often worse than professional recommendations.

Maggot Treatment of Necrotic Toe Developed After Traumatic Subtotal Amputation.

Maggot debridement therapy (MDT) has been used for years in the treatment of chronic wounds and necrotic tissues. We report a case of subtotally amputated third toe that was treated with MDT after reattachment and developing complete necrosis. The necrotic toe was replaced with viable tissue and the wound healed completely after 2 weeks of MDT application. This case points out the regenerative effects of MDT besides its mechanical debridement effect on the necrotic tissue.

Severe Intrahepatic Cholestasis Pregnancy Is Associated With Maternal Endothelial Dysfunction: A Case-Control Study.

OBJECTIVE: The aim of the present study was to evaluate maternal serum endocan levels, which are markers of vascular pathologies and strongly associated with vascular inflammation and endothelial dysfunction, in pregnancies complicated by intrahepatic cholestasis of pregnancy (ICP). METHODS: The study comprised 30 pregnant women with mild ICP, 30 pregnant women with severe ICP, and 30 healthy pregnant women as a control group. The inclusion criteria were women with ICP, which was diagnosed based upon the presence of pruritus associated with elevated total bile acid (TBA) levels (> 10 µm/L), elevated aminotransferases, or both, and the absence of diseases that may produce similar laboratory findings and symptoms. Severe ICP was defined as TBA > 40 µmol/L. After diagnosis for ICP, blood samples were obtained before medication during hospitalization to analyze maternal serum endocan levels. RESULTS: Gestational age at delivery, delivery induction rates, birth weight, and newborn intensive care unit (NICU) admission rates were significantly higher in the severe ICP group than in the control group and mild ICP group. Gestational age for all groups when blood was sampled was similar. Maternal serum TBAs and aminotransferase levels were significantly higher in the severe ICP group than in the control group and mild ICP group. The mean serum endocan levels were 10.9 ± 2.6 ng/mL in the control group, 12.5 ± 2.8 ng/mL in the mild ICP group, and 24.3 ± 4.8 ng/mL in the severe ICP group (p < 0.001). CONCLUSION: Our results indicated that maternal serum endocan levels were increased in the presence of severe ICP and it can be speculated that increased bile acid levels were associated with maternal endothelial dysfunction.

Evaluation of Altmetric Analysis Scores of the Top 100 Articles on Polycystic Ovary Syndrome Published in the Last 10 Years.

OBJECTIVE: In the current study, we analyzed the 100 most cited articles with the topic, title, and keywords of polycystic ovary syndrome (PCOS) published in all journals in terms of traditional metrics and the altmetric score (AS). METHODS: The term "polycystic ovary syndrome (PCOS)" was searched in the Web of Science (WoS) database and filtered for articles published in all journals. Bibliographic data and AS were obtained for 100 highly cited papers from January 2012 to July 2022. Descriptive statistics were reported and correlation analysis between traditional bibliographies and the AS was performed. RESULTS: The Journal of Clinical Endocrinology & Metabolism, with 14 articles, had the most publications on the Top 100 list. When the studies were classified according to subtypes, 56 papers were original scientific papers with mean AS of 32.5 (15.3-52.7), whereas 44 papers were reviews and meta-analyses with AS of 16.0 (8.6-43.2). The AS was positively correlated with H-index, total WoS citation number of article and Q category. There were no correlations with impact factor (IF), five-year IF, journal impact factor (JIF) percentile and journal citation indicator (JCI) value. CONCLUSION: Our results suggest that the AS is related with article total WoS citation number, journal Q category, and journal H-index. Effective communication on social media can promote scientific productivity and have a positive impact on society.

Optical modelling of an accommodative light field display system and prediction of human eye responses.

The spatio-angular resolution of a light field (LF) display is a crucial factor for delivering adequate spatial image quality and eliciting an accommodation response. Previous studies have modelled retinal image formation with an LF display and evaluated whether accommodation would be evoked correctly. The models were mostly based on ray-tracing and a schematic eye model, which pose computational complexity and inaccurately represent the human eye population's behaviour. We propose an efficient wave-optics-based framework to model the human eye and a general LF display. With the model, we simulated the retinal point spread function (PSF) of a point rendered by an LF display at various depths to characterise the retinal image quality. Additionally, accommodation responses to the rendered point were estimated by computing the visual Strehl ratio based on the optical transfer function (VSOTF) from the PSFs. We assumed an ideal LF display that had an infinite spatial resolution and was free from optical aberrations in the simulation. We tested points rendered at 0-4 dioptres of depths having angular resolutions of up to 4x4 viewpoints within a pupil. The simulation predicted small and constant accommodation errors, which contradict the findings of previous studies. An evaluation of the optical resolution on the retina suggested a trade-off between the maximum achievable resolution and the depth range of a rendered point where in-focus resolution is kept high. The proposed framework can be used to evaluate the upper bound of the optical performance of an LF display for realistically aberrated eyes, which may help to find an optimal spatio-angular resolution required to render a high quality 3D scene.

Proximal femoral nail antirotation versus cemented calcar-replacement hemiarthroplasty for unstable intertrochanteric fracture in elderly: an overall survival study.

BACKGROUND: The aim of this study is to compare the perioperative complications and overall survival of patients who underwent proximal femoral nail antirotation (PFNA) and patients who underwent cemented calcar-replacement hemiarthroplasty (CCRH) for unstable intertrochanteric fracture in patients aged 75 years and older. METHODS: A total of 94 patients who underwent PFNA or CCRH between 2010 and 2012 because of femur fracture (A2.2 and A2.3 according to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) classification) were analyzed retrospectively. Hospitalization times, blood transfusion needs, reoperation rates, and overall survival were compared. RESULTS: Forty-eight patients in the PFNA group and 46 patients in the CCRH group were included for analysis. There was no statistically significant difference between the two groups in terms of hospitalization times, blood transfusion needs, reoperation rates, and survival rates. DISCUSSION: Both PFNA and CCRH techniques can be used for surgical treatment of unstable intertrochanteric femur fractures.