Femtosecond-Assisted Mushroom Deep Anterior Lamellar Keratoplasty.

PURPOSE: The aim of this study was to describe our technique for performing femtosecond laser (FSL)-assisted mushroom configuration in deep anterior lamellar keratoplasty (DALK). METHODS: We describe our surgical technique for a mushroom-configuration DALK using a femtosecond laser (FSL) both to prepare the graft and to perform a precut of the recipient cornea, as well as the steps for the dissection of the recipient cornea and for donor cornea implantation. Moreover, we show the parameters of energy and spot separation and the external and internal diameters as well as the thickness of the external and internal keratotomy. RESULTS: We performed a retrospective case series study of 20 patients with a mean follow-up of 4.36 ± 2.54 years. The indication for surgery was leukoma in 15 cases (75%), keratoconus in 4 cases (20%), and stromal corneal dystrophy in 1 case (5%). Four cases had to be converted to penetrating keratoplasty. The overall results were as follows: The mean preoperative corrected distance visual acuity increased from 0.11 ± 0.09 (0.01-0.30) to 0.78 ± 0.22 (0.30-1.0) with spectacles and to 0.92 ± 0.13 (0.5-1.0) with a gas permeable contact lens. The mean final cylinder was 3.90 ± 1.86 (1.25-7.0). The mean endothelial cell count at 6 months was 2033.83 ± 570.53 cells/mm2 (930-3207), and the mean final spherical equivalent was -4.67 ± 2.91 (-0.25 to -9.00). CONCLUSIONS: FSL-assisted technology is useful to achieve a predictable and safe procedure when using mushroom configuration to perform DALK. Our conversion rate from DALK to penetrating keratoplasty was similar to or even lower than that reported in the literature. In the successful DALK cases, the visual and refractive results were similar to those reported in other studies using FSL-assisted DALK (with a standard or mushroom configuration).

Descemet Membrane Endothelial Keratoplasty and Descemet Stripping Only Using a 3D Visualization System.

(1) Purpose: The aim was to analyze the outcomes of Descemet's membrane endothelial keratoplasty (DMEK) and Descemet stripping only (DSO) surgeries using a glasses-assisted NGENUITY® 3D visualization system (Alcon Laboratories, Fort Worth, TX, USA). (2) Methods: Five consecutive cases of DMEK surgery and four consecutive cases of DSO were performed using the NGENUITY® system in this prospective study carried out at the Arruzafa Hospital, Córdoba, Spain. Only one eye from each patient received surgery. Best corrected distance visual acuity (CDVA) using EDTRS charts, central corneal thickness using the Casia II optical coherence tomograph (Tomey Co., Nagoya, Japan), and endothelial cell count using the Tomey EM-4000 (Tomey Co., Nagoya, Japan) for DMEK cases or the Nidek CEM-530 (Nidek Co., Ltd., Gamagori, Japan) specular microscopes for DSO cases were recorded preoperatively and at 1 and 3 months postsurgery. (3) Results: DMEK cases included one male and four female subjects, with a mean age of 73.6 ± 9.5 years. Average improvement in CDVA 3 months after surgery was 0.46 ± 0.16 decimal. Average change in cell count between 1 and 3 months postsurgery was 360.75 ± 289.38 cells/mm2. DSO cases included four female subjects, with a mean age of 64.2 ± 9.7 years. The average improvement in CDVA 3 months after surgery was 0.09 ± 0.17 decimal. All cases also had phacoemulsification carried out. He average change in cell count between 1 and 3 months after surgery was 460 ± 515.69 cells/mm2. There were no associated complications during surgery or the follow-up period in any of the cases. (4) Conclusions: In addition to the known benefits of the use of a 3D visualization system during surgery, the present study shows that the system can be successfully used in both DMEK and DSO procedures with a very short learning curve for the surgeon.

Visual Performance, Satisfaction, and Spectacle Independence after Implantation of a New Hydrophobic Trifocal Intraocular Lens.

The main objective was to evaluate distance, intermediate, and near vision in patients who have undergone cataract extraction with bilateral implantation of a new trifocal diffractive intraocular lens (IOL), along with patient-reported outcomes (PRO). A total of 50 eyes from 25 patients after AsqelioTM Trifocal IOL (AST Products, Inc., Billerica MA, USA) implantation were assessed in this study. At 3 months after surgery, the photopic visual acuity (VA) at distance, intermediate, and near distances was measured. Binocular photopic defocus curves were also obtained. Three questionnaires to assess patients' visual satisfaction and spectacle dependence, among other items, were completed: the Catquest-9SF, the patient-reported spectacle independence questionnaire (PRSIQ), and the patient-reported visual symptoms questionnaire (PRVSQ). The average spherical equivalent was 0.21 ± 0.37 D at 3 months post-operation, and the average absolute tolerance to defocus was 3.64 ± 0.70 D. The mean binocular uncorrected VAs for distance, intermediate, and near vision were -0.02 ± 0.09, 0.06 ± 0.08, and 0.11 ± 0.07 logMAR, respectively. The best-corrected VA was better than 0.1 logMAR for the whole range from distance to near. PROs revealed spectacle independence and general satisfaction with vision, and the incidence of photic phenomena were low. This study shows that the new bi-aspheric diffractive trifocal IOL provides a good visual performance at different distances under photopic conditions, accompanied by patient satisfaction and spectacle independence.

Early patient-reported outcomes of cataract surgery with implantation of the trifocal liberty 677MY intraocular lens: A pilot study.

PURPOSE: To report our first clinical and patient-reported outcomes in the early postoperative period with a new model of trifocal diffractive intraocular lens (IOL). METHODS: Pilot prospective analysis of the results of 26 eyes of 13 patients (age, 44-79 years) undergoing cataract surgery with implantation of the trifocal diffractive IOL Liberty 677MY (Medicontur Medical Engineering Ltd., Zsámbék, Hungary). The following clinical outcomes were evaluated during the first postoperative month: measurement of distance, intermediate and near visual acuity, binocular defocus curve, and level of spectacle independence, patient satisfaction, perception of photic phenomena, and difficulty in performing several vision-related daily tasks by means of a questionnaire. RESULTS: Mean binocular LogMAR uncorrected distance, intermediate and near visual acuities were -0.03 ± 0.13, 0.21 ± 0.16, and 0.16 ± 0.09, respectively. Furthermore, 100.0%, 84.6% and 92.3% of patients achieved a binocular corrected distance, distance-corrected intermediate and distance-corrected near visual acuity of 20/32 or better, respectively. In the defocus curve, visual acuities were better than 0.2 logMAR for defocus levels between +1.00 and -3.00 D. Spectacle independence was referred by all patients, with any of them reporting dissatisfaction with the outcome of the surgery. The postoperative vision did not lead to difficulties in the daily life in 92.3% of patients. Bothersome halos, glare or starbursts were only reported by only 7.7% of patients. CONCLUSIONS: The trifocal IOL evaluated provides a successful visual rehabilitation with minimal photic phenomena associated, leading to high levels of spectacle independence and patient satisfaction.

The Influence of Dimensions and Powder Recycling on the Roughness and Mechanical Properties of Ti-6Al-4V Parts Fabricated by Laser Powder Bed Fusion.

Powder bed fusion technology has undergone a remarkable amount of development in recent years in the field of medical implants due to the advantages associated with it. In many implant applications that demand loads in parts with a high degree of roughness and small dimensions, the mechanical properties, especially fatigue properties, play a key role in the success of the implants. One of the most used materials in this field is Ti-6Al-4V. On the other hand, the high cost of titanium powders makes it necessary to search for suitable powder recycling strategies. In this work, the effects of dimensions and powder recycling on the roughness and the mechanical properties of cylinder specimens were obtained from tensile static and fatigue tests of Ti-6Al4V Extra-Low Interstitial (ELI) parts. Four types of specimens were fabricated by laser powder bed fusion (two dimensions (section diameters of 2 mm and 5 mm) with new powder and with recycled powder). Results show that the oxygen concentration increased with recycling. No significant effects of recycling were observed on the monotonic tensile strength specimens. However, specimens fabricated with recycled powder showed greater roughness, lower ductility, and lower fatigue strength than those fabricated with new powder. On the other hand, the 5-mm-diameter specimens showed slightly better fatigue behavior than the 2-mm-diameter ones.

Stiffness reduction of the rib cage to perform a minimally invasive pectus excavatum repair: biomechanical evaluation.

OBJECTIVES: To study the influence of sternal transection and costal chondrotomies on the stiffness and stresses in the rib cage of adult patients undergoing Nuss pectus excavatum procedure. METHODS: Four pectus excavatum models with different Haller indexes were created by parameterizing a 3D model of a rib cage obtained based on a computed tomography scan of a patient with no pectus deformity. Using the finite element method, insertion of intrathoracic bars into all models was simulated in 3 conditions, namely, non-intervened, transverse sternal section and costal chondrotomies. Stiffness, stress distribution and maximum stresses for each case were obtained and compared. RESULTS: Transverse sternotomy provided a reduction of 44% to 54% in the stiffness of the rib cage, depending on the Haller index analysed, while chondrotomies promoted a stiffness reduction of 70%. Stress distribution in the rib cage followed similar pattern for all the tested Haller index, but the maximum stress decreased by 36% when performing a transverse sternotomy, whereas when performing costal chondrotomies, it decreased by 47%. CONCLUSIONS: Computational results report that transverse sternotomy reduces appreciably the stiffness of the rib cage, while costal chondrotomies promote even a higher stiffness reduction. Thus, these surgical procedures could improve the clinical outcomes of adult patients undergoing a pectus excavatum repair.

Recommendations for ophthalmologic practice during the easing of COVID-19 control measures.

In the context of the COVID-19 pandemic, this paper provides recommendations for medical eye care during the easing of control measures after lockdown. The guidelines presented are based on a literature review and consensus among all Spanish Ophthalmology Societies regarding protection measures recommended for the ophthalmologic care of patients with or without confirmed COVID-19 in outpatient, inpatient, emergency and surgery settings. We recommend that all measures be adapted to the circumstances and availability of personal protective equipment at each centre and also highlight the need to periodically update recommendations as we may need to readopt more restrictive measures depending on the local epidemiology of the virus. These guidelines are designed to avoid the transmission of SARS-CoV-2 among both patients and healthcare staff as we gradually return to normal medical practice, to prevent postoperative complications and try to reduce possible deficiencies in the diagnosis, treatment and follow-up of the ophthalmic diseases. With this update (5th ) the Spanish Society of Ophthalmology is placed as one of the major ophthalmology societies providing periodic and systematized recommendations for ophthalmic care during the COVID-19 pandemic.

Connection between the Gut Microbiome, Systemic Inflammation, Gut Permeability and FOXP3 Expression in Patients with Primary Sjögren's Syndrome.

The aims of this study were to explore intestinal microbial composition and functionality in primary Sjögren's syndrome (pSS) and to relate these findings to inflammation, permeability and the transcription factor Forkhead box protein P3 (FOXP3) gene expression in peripheral blood. The study included 19 pSS patients and 19 healthy controls matched for age, sex, and body mass index. Fecal bacterial DNA was extracted and analyzed by 16S rRNA sequencing using an Ion S5 platform followed by a bioinformatics analysis using Quantitative Insights into Microbial Ecology (QIIME II) and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt). Our data suggest that the gut microbiota of pSS patients differs at both the taxonomic and functional levels with respect to healthy controls. The gut microbiota profile of our pSS patients was characterized by a lower diversity and richness and with Bacteroidetes dominating at the phylum level. The pSS patients had less beneficial or commensal butyrate-producing bacteria and a higher proportion of opportunistic pathogens with proinflammatory activity, which may impair intestinal barrier function and therefore contribute to inflammatory processes associated with pSS by increasing the production of proinflammatory cytokines and decreasing the release of the anti-inflammatory cytokine IL-10 and the peripheral FOXP3 mRNA expression, implicated in the development and function of regulatory T cells (Treg) cells. Further studies are needed to better understand the real impact of dysbiosis on the course of pSS and to conceive preventive or therapeutic strategies to counteract microbiome-driven inflammation.

Does the modelling of the pectus bar affect its stability? Rationale for using a short flat bar.

OBJECTIVES: Although the Nuss procedure for pectus excavatum is still associated with a non-negligible risk of postoperative bar displacement, the potential effects of the length and shape of the bar on its corrective ability and stability have not been sufficiently studied. The aim of this study was to determine how the modelling of the pectus bar affects its stability and whether an alternative configuration of the implant can improve clinical success. METHODS: Simulated implantation of bars with different shapes and sizes in a computational model was carried out. A 250 N sternal force was applied to the bars, and the resulting forces and moments on the fixation points were identified. Afterwards, a clinical trial was carried out in a group of patients with pectus excavatum, some of whom received long inverted U-shaped bars and some of whom received implants designed from the computational results. RESULTS: When U-shaped bars were tested, the sternal force generated unbalanced horizontal reaction forces (16 vs 61 N) and large reaction moments at the ends of the bar, conferring the tendency to slide and to rotate, respectively. No lateral or rotational destabilizing forces occurred in the case of a flat bar. Cosmetic outcomes, postoperative times and hospital stays were similar in both clinical groups. However, 2 cases (2/15) of bar flipping occurred in patients who received the conventional bar. CONCLUSIONS: The shape of the bar is a determinant of its stability. A flat, shorter pectus bar provides adequate correction of the deformity with less tendency for bar displacement in the repair of pectus excavatum.

Does thread shape affect the fixation strength of the bioabsorbable interference screws for anterior cruciate ligament reconstructions? A biomechanical study.

BACKGROUND: The purpose of this study was to compare the biomechanical behaviour of two bioabsorbable interference screws with different geometries. METHODS: Two different pitch (2.5 and 5 mm) bioabsorbable interference screws, both 9 × 30 mm, were tested. Tests were performed with forty bovine digital extensor tendons and skeletally mature porcine tibiae. Two protocols of cyclic tests at 1 Hz were performed: 1000 cycles from 50 to 250 N, and 5000 cycles from 100 to 300 N (n = 10 for each type of test and screw). After the cyclic loading, a final ramp displacement until failure at 0.5 mm/s was applied. RESULTS: The stiffness after the cyclic phase of the tests was not statistically different between the two screws (1000th cycle: 2.5 mm pitch 280.3 ± 56.4 N/mm, 5 mm pitch 275.2 ± 65.0 N/mm, P = .965; 5000th cycle: 2.5 mm pitch 281.3 ± 66.4 N/mm, 5 mm pitch 286.1 ± 79.4 N/mm, P = .814). The yield load was not significantly different between the screws (1000 cycle tests: 2.5 mm pitch 482.2 ± 120.2 N, 5 mm pitch 495.9 ± 131.3 N, P = .508; 5000 cycle tests: 2.5 mm pitch 476.4 ± 65.3 N, 5 mm pitch 494.3 ± 39.2 N, P = .391). No correlation was found between the insertion torque and yield load (1000 cycle tests, R2 = 0.013; 5000 cycle tests, R2 = 0.006). CONCLUSIONS: The pitch of bioabsorbable interference screws does not seem to affect fixation strength. Also, the authors recommend not to use insertion torque alone to estimate the fixation strength.

Espaciadores de cadera en cirugía de revisión en dos tiempos / Spacers in two-stage hip revision surgery

Objetivo: Comunicar nuestra experiencia en cirugía de revisión en dos tiempos por aflojamiento séptico de artroplastia total de cadera (ATC) con distintos modelos de espaciadores y las ventajas del espaciador articulado respecto a otras alternativas. Material y metodos: 17 casos tratados en los últimos 4 años en los que hemos empleado bloques manuales de cemento (4), espaciadores estándar (6), y espaciadores articulados (7). El seguimiento medio de los casos es de 25 meses y el seguimiento mínimo de 12 meses. Resultados: De los 6 casos con espaciadores estándar hemos tenido 2 fracturas peri-implantes y 2 recidivas de la infección. Los espaciadores con bloques manuales de cemento requieren estancias más prolongadas y mayor dificultad en el segundo tiempo de la cirugía. En los 7 casos con espaciadores articulados no hemos tenido complicaciones respecto a luxación, fracturas peri-implante, ni reinfección. Conclusiones: Defendemos el uso de espaciadores articulados ya que evitan el acortamiento del miembro afectado, pueden adaptarse al diámetro del canal endomedular del fémur, minimizan la contractura de los tejidos blandos y disminuyen las complicaciones respecto a otras alternativas. Permiten la marcha autónoma del paciente entre los dos tiempos de la cirugía y facilitan el reimplante en un segundo tiempo

Objective: The main objective is to communicate our experience in two-stage revision surgery in chronic hip infection after THA with different types of spacers and the advantages of the articulating spacer compared to other alternatives. Material and methods: We have analyzed 17 cases in the last 4 years in which we have used static spacers (6), cement blocks (4), and articulating spacers (7). The average follow-up of the cases is 25 months and the minimum follow-up was 12 months. Results: From the 6 cases with standard spacers, 2 of them result on peri-implant fractures and another 2 suffered recurrences of the infection. Spacers with manual cement blocks required prolonged hospital stay and greater difficulty in the second surgery time. Those cases treated with articulating spacers (7), did not showed complications regarding to dislocation, peri-implant fractures, or reinfection. Conclusion: We defend the use of articulating spacers as they avoid the shortening of the affected lower limb, minimize the contracture of soft tissues and reduce complications with regard to other alternatives. They allow the autonomous march of the patient between the two times of surgery and make easier the reimplantation in a second time

Vástagos cortos versus convencionales en artroplastia total de cadera: nuestra experiencia / Short versus conventional stems in Total hipShort versus conventional stems in Total hiparthroplasty: Our experience

Objetivo: Evaluar la incidencia de complicaciones y la calidad de vida tras la cirugía en dos grupos de pacientes sometidos a artroplastia total de cadera no cementadas con vástagos corto y con vástagos estándar. Material y Métodos: Se realiza un estudio retrospectivo sobre un total de 106 artroplastias total de cadera implantadas en el Hospital Universitario de Puerto Real entre 2011 y 2015. Se comparan las siguientes variables: estancia hospitalaria, necesidad de transfusión sanguínea, complicaciones mecánicas, necesidad de revisión por cualquier causa, parámetros radiológicos (reabsorción del calcar, hundimiento, dismetría postquirúrgica, metría de cuello remanente) y dolor en cara anterior de muslo en dos grupos homogéneos de 63 vástagos convencionales anatómicos no cementados con 43 vástagos cortos de estabilización metafisaria y preservación parcial del cuello femoral ("partial collum"), implantadas por un mismo cirujano. Para el análisis estadístico se utilizó la T de Student para el análisis de variables cuantitativas y Chi cuadrado para variables cualitativas. Resultados: Los resultados muestran diferencias estadísticamente significativas (p< 0.05) en cuanto a variables estancia hospitalaria postquirúrgica, fracturas periprotésicas, dismetría, complicaciones mecánicas y metría del cuello remanente. Conclusiones: Los resultados avalan el empleo de vástagos cortos de estabilización metafisaria y preservación parcial del cuello femoral en pacientes jóvenes con adecuada calidad ósea y bien seleccionados, dadas las ventajas clínicas que suponen

Objetives: To evaluate the incidence of complications and the quality of life after surgery in two groups of patients undergoing total hip arthroplasty not cemented with a short stem and with a standard uncemented stem. Material and Methods: A retrospective study was performed in a total of 106 total hip arthroplasties implanted in the University Hospital of Puerto Real between 2011 and 2015. The following variables are compared: hospital stay, need for blood transfusion, mechanical complications, need for revision for any reason , radiological parameters (calcar resorption, subsidence, postsurgical dysmetria, remnant neck metrics) and anterior thigh pain in two homoge-nous groups of 63 conventional uncemented anatomical stems with 43 short stems of metaphyseal stabilization and partial femoral neck preservation ("Partial collum"), implanted by the same surgeon. For the statistical analysis, T Student was used for the analysis of quantitative variables and Chi-square for qualitative variables. Results: The results show statistically significant differences (p < 0.05) in terms of postsurgical hospital stay variables, periprosthetic fractures, dysmetria, mechanical complications and metrics of the remaining neck. Conclusions: The results support the use of short stems of metaphyseal stabilization and preservation of the greater trochanter in young patients with adequate bone quality given the clinical advantages they imply

Influence of the number and position of stripped screws on plate-screw construct biomechanical properties.

INTRODUCTION: Screw stripping is a common situation in fracture fixation, particularly in osteopenic bone treatment. Surgeons' perception of screw stripping is relatively poor and the real number of loose screws in every plate-screw construct is unknown. The biomechanical and clinical implications of the different possible screw-stripping situations are also unidentified. In this study, construct stiffness in different scenarios of stripped screws is investigated. METHOD: A bone surrogate comminuted osteoporotic fracture was fixed with four screws in both sides of the fracture gap in 75 specimens. In four groups, one or two screws closest or distal to the gap were over-tightened and left in place in one part of the construct and the remaining screws were tightened with 0.3N m torque (four groups). In the fifth group (control), all the screws were tightened with 0.3N m torque. Construct stiffness was tested in terms of compression, bending, and torsion for 1000 cycles. RESULTS: When one or two screws closest to the gap were stripped, stiffness only decreased by, respectively, 5.7% or 7.6% under compression and 4.7% or 6.7% under bending; however, stiffness in torsion was 15.1% or 32%, respectively, lower than the initial stiffness. When a screw distal to the gap was stripped, the stiffness decreased by 28% under bending and 10% under compression; no change was noted under torsion. When two screws distal to the gap were stripped, the stiffness decreased by 11% in compression, collapsed under bending, and decreased by 8% under torsion. CONCLUSIONS: Position and number of stripped screws affect the biomechanical properties of a construct in different ways, depending on the acting forces.

Can an expansion device be used in anterior cruciate ligament reconstruction? An in vitro study of soft tissue graft tibial fixation.

BACKGROUND: The purpose of this study was to compare the mechanical properties of an interference screw with an expansion device in anterior cruciate ligament (ACL) reconstruction. METHODS: A total of 52 porcine tibia and 20 polyurethane foam blocks (0.16g/cm3) were used. Forty pullout tests were carried out to combine the two types of bones - surrogate and porcine - with the two fixation systems: interference screw and expansion device (n=10 per group). Thirty-two cyclic tests (n=8 per group) were carried out with both fixation devices in porcine bone at two different force amplitudes (100N and 200N). RESULTS: Stiffness and load values (mean±SD) at six millimeters of displacement for the expansion device and the interference screw were 74±33N/mm, 318±135N, and 52±28N/mm, 205±70N, respectively, showing a difference in stiffness (P=0.016) and load at six millimeters of displacement (P=0.001). No correlation between insertion torque and the ultimate failure load was found for both fixation devices tested. In cyclic tests, significantly higher (P<0.001) numbers of cycles (mean±SD) were reached with the expansion device (81,014±30,291 at 100N; 13,462±11,351 at 200N) than with the interference screw (15,100±8623 at 100N; 343±113 at 200N) at six millimeters of displacement. CONCLUSION: The use of an expansion device for ACL reconstructions seemed to be a promising alternative to an interference screw. Insertion torque alone was not a useful predictor of graft fixation strength in ACL reconstructions.

Use of screw locking elements improves radiological and biomechanical results of femoral osteotomies.

BACKGROUND: Dynamic compression plate (DCP) constructs provide inadequate fixation in cases of poor bone quality and early weight-bearing. Screw locking elements (SLE) are flat locking nuts placed at the end of the screw to prevent screw stripping from the bone, improving fixation stability. The purpose of this work was to compare biomechanical and radiological evaluations of femoral ovine osteotomies fixed using DCP constructs with and without SLE. METHOD: A dyaphyseal femoral osteotomy was performed in sixteen adult sheep and fixed with a DCP and cortical screws. Half of the animals were operated on with a SLE on each side of the osteotomy and the rest without the addition of SLE. Four animals of each group were euthanized after 8 weeks, and the remaining after 16 weeks. Both femora of each animal were radiographed and mechanically tested in torsion. RESULTS: Radiologically femoral malalignment or screw loosening was observed in six out of the eight animals operated on without SLE. In contrast, all animals subjected to the operation with SLE showed complete radiological consolidation of the osteotomy. Seven of these eight animals showed normal femoral alignment and no osteosynthesis failure. Stiffness of the bones fixed with SLE was among 145% and 177% the value of their contralateral non-operated femurs (all animals of this group showed greater stiffness on the operated bone than its contralateral non-operated femur). However, stiffness of the bones operated on without SLE was among 58% and 87% the value of the stiffness of their contralateral non-operated bone (all animals of this group showed greater stiffness on the non-operated bone than the osteotomized ones). CONCLUSIONS: Use of SLE avoided loosening of the system and stimulated stronger osteotomy consolidation. Clinical application of this improved system may thus be a feasible and cost-effective alternative to other more rigid and expensive bone fixation techniques.