Optical constants, band gap, and infrared-active phonons of (LaAlO₃)_0.3(Sr₂AlTaO₆)_0.35 (LSAT) from spectroscopic ellipsometry

Using spectroscopic ellipsometry, the authors determined the optical constants (complex dielectric function) for (LaAlO₃)0.3(Sr₂AlTaO₆) 0.35 (LSAT) from 0.01 to 6.5 eV. Above 0.5 eV, the data were described with a sum of two Tauc-Lorentz oscillators and two poles. A direct gap of 5.8 ± 0.1 eV was found. An Urbach tail extends to even lower photon energies and makes the crystal opaque above 4.8 eV. Using Fourier-transform infrared ellipsometry, the lattice dynamics was studied. Nine pairs of transverse/longitudinal phonons were found and attributed to disorder in the La/Sr sublattice, ordering in the Al/Ta sublattice, and two- phonon absorptio

Inferior outcome after hip resurfacing arthroplasty than after conventional arthroplasty: Evidence from the Nordic Arthroplasty Register Association (NARA) database, 1995 to 2007

Today, total hip arthroplasty (THA) is one of the safest and most efficient surgical treatments. New materials, surgical techniques and design concepts intended to improve THA have not always been successful. Thorough preclinical and early clinical investigations can detect some aspects of under-performing, while continuing surveillance is recommended to detect and analyze reasons for any later appearing flaws. In this thesis, several ways to monitor and assess THA performance are explored and carried out, using survival analysis in registry studies, radiostereometry (RSA), radiology and clinical outcome. In Paper I, a study using the Nordic Arthroplasty Register Association (NARA) registry shows that HRA had an almost 3-fold increased early non-septic revision risk and that risk factors were found to be female sex, certain HRA designs and units having performed few HRA procedures. Papers II and III contain comparisons of highly cross-linked polyethylene (XLPE) and conventional polyethylene (PE). XLPE had a considerably lower wear rate up to 10 years but showed no obvious improvements regarding implant fixation, BMD or clinical outcome. In the NARA registry, in 2 of 4 studied cup designs the XLPE version had a lower risk of revision for aseptic loosening compared to the PE version. Paper IV describes that stem subsidence and retrotorsion measured with RSA at 2 years predicted later aseptic stem failure in an unfavorably altered, previously well-functioning cemented femoral stem. In Paper V and VI, a novel approach to measure articulation wear with RSA in radiodense hip arthroplasty articulations was presented and evaluated. Subsequently, a comparison between ceramic-on-ceramic (COC) and metal-on-conventional PE uncemented THA displayed a considerably lower wear rate, smaller periacetabular bone lesions and a relatively high squeaking rate, the latter with unknown long-term consequences, in the COC hips. Implant fixation, heterotopic ossification and clinical outcome did not differ between articulation types. In conclusion, it was confirmed that implant surveillance can be done with RSA, also in radiodense THA. Early migration predicts later aseptic implant failure. Prolonged surveillance can confirm long-term material and design performance, verify or contradict anticipated advantages as well as detect unanticipated long-term complications

Microbiological profiles of sputum and gastric juice aspirates in Cystic Fibrosis patients.

Gastro-Oesophageal Reflux (GOR) is a key problem in Cystic Fibrosis (CF), but the relationship between lung and gastric microbiomes is not well understood. We hypothesised that CF gastric and lung microbiomes are related. Gastric and sputum cultures were obtained from fifteen CF patients receiving percutaneous endoscopic gastrostomy feeding. Non-CF gastric juice data was obtained through endoscopy from 14 patients without lung disease. Bacterial and fungal isolates were identified by culture. Molecular bacterial profiling used next generation sequencing (NGS) of the 16S rRNA gene. Cultures grew bacteria and/or fungi in all CF gastric juice and sputa and in 9/14 non-CF gastric juices. Pseudomonas aeruginosa(Pa) was present in CF sputum in 11 patients, 4 had identical Pa strains in the stomach. NGS data from non-CF gastric juice samples were significantly more diverse compared to CF samples. NGS showed CF gastric juice had markedly lower abundance of normal gut bacteria; Bacteroides and Faecalibacterium, but increased Pseudomonas compared with non-CF. Multivariate partial least squares discriminant analysis demonstrated similar bacterial profiles of CF sputum and gastric juice samples, which were distinct from non-CF gastric juice. We provide novel evidence suggesting the existence of an aerodigestive microbiome in CF, which may have clinical relevance

Microbiological profiles of sputum and gastric juice aspirates in Cystic Fibrosis patients

Gastro-Oesophageal Reflux (GOR) is a key problem in Cystic Fibrosis (CF), but the relationship between lung and gastric microbiomes is not well understood. We hypothesised that CF gastric and lung microbiomes are related. Gastric and sputum cultures were obtained from fifteen CF patients receiving percutaneous endoscopic gastrostomy feeding. Non-CF gastric juice data was obtained through endoscopy from 14 patients without lung disease. Bacterial and fungal isolates were identified by culture. Molecular bacterial profiling used next generation sequencing (NGS) of the 16S rRNA gene. Cultures grew bacteria and/or fungi in all CF gastric juice and sputa and in 9/14 non-CF gastric juices. Pseudomonas aeruginosa(Pa) was present in CF sputum in 11 patients, 4 had identical Pa strains in the stomach. NGS data from non-CF gastric juice samples were significantly more diverse compared to CF samples. NGS showed CF gastric juice had markedly lower abundance of normal gut bacteria; Bacteroides and Faecalibacterium, but increased Pseudomonas compared with non-CF. Multivariate partial least squares discriminant analysis demonstrated similar bacterial profiles of CF sputum and gastric juice samples, which were distinct from non-CF gastric juice. We provide novel evidence suggesting the existence of an aerodigestive microbiome in CF, which may have clinical relevance

Mid Term Followup of Patient Reported Outcomes in Patients <50 years with a Total Ankle Arthroplasty

Category: Ankle Arthritis Introduction/Purpose: End stage arthritis is a debilitating condition that significantly affects patients’ quality of life. Ankle arthritis differs from arthritis of the hip and knee in that ankle arthritis is often posttraumatic in nature and affects a younger patient population. Historically, younger age was a contraindication to total ankle arthroplasty (TAA) and ankle arthrodesis was the mainstay of treatment. Advances in TAA implant design and revision implants has expanded indications and increased usage of TAA. Despite this, many surgeons remain hesitant due to the lack of long term data on patient outcomes and survivorship in these patients. The purpose of our study was to evaluate patient reported outcome measures and survivorship after primary TAA in patients < 50 years of age at the time of surgery. Methods: A retrospective chart review was conducted of patients < 50 years of age who underwent primary TAA at a single institution from 2010-2020. Patient demographics, outcome measures, and complications were recorded. All patients had a minimum clinical follow up of 5 years. Patient reported outcome (PRO) measures collected included FADI, VAS, SMFA SF-36, AOFAS hindfoot scores, and FAOS scores. Outcome measures were evaluated preoperative, 1 year postoperative, and at final clinical follow up. Paired t-tests were performed to compare individual patients’ changes in PRO from preoperative to postoperative timepoints. Multiple comparisons correction was performed using the Bonferroni method. Implant survivorship was evaluated based on need for revision of either the tibial or talar component. Results: A total of 59 patients were included in the study. The average age at time of surgery was 43.2 years. All patients had a minimum follow up of 5 years with a mean follow up time of 8.8 years. Mean FADI improved from 53.3 (sd:14.1) preoperatively to 16.1 (sd:11.4) (p < 0.001) at 1-year postoperatively. Mean VAS and SMFA also improved from preoperative to 1-year postoperative timepoints [VAS: 68.2 (sd:27.0) to 10.3(sd:13.1) (p < 0.001); SMFA: 36.1 (sd:12.2) to 14.8 (sd:13.7) (p < 0.001)]. A total of 5 patients required revision of components during the follow up period. Three patients required complete revision of both tibial and talar components, 2 due to aseptic loosening and 1 due to deep infection requiring explant of components. Conclusion: Patients < 50 years undergoing TAA for end stage ankle arthritis have improved patients reported outcomes greater than 5 years after surgery. Despite the increased demands of the younger population, survivorship of total ankle implants in our study was 85% at a mean of 8.8 years postoperative. We believe that TAA is a safe and reliable option for young patients with high patient satisfaction at mid term follow up

Early to Mid-Term Follow-up of Total Ankle Arthroplasty in Patients <35 Years

Category: Ankle Arthritis; Ankle Introduction/Purpose: Younger age remains at the forefront of discussion when deciding between total ankle arthroplasty (TAA) and the ankle arthrodesis (AA) for treatment of end stage ankle arthritis. Unlike in the hip and knee, ankle arthritis is typically post-traumatic and presents at a much younger patient age. With the goal of preserving ankle motion, improving function and limiting adjacent joint degeneration, TAA has been shown to be safe and effective in patients < 55 years of age. However, it is not uncommon for debilitating ankle arthritis to occur in individuals within their fourth or even third decade of life resulting in significant patient comorbidity. The purpose of our study was to evaluate patient reported outcome measures and survivorship after primary TAA in patients < 35 years old. Methods: A retrospective chart review was conducted of patients < 35 years old who underwent primary TAA at a single institution from 2007-2020. Patient demographics, outcome measures, and complications were recorded. All patients had a minimum clinical follow up of 2 years. Patient reported outcome measures collected included VAS, SMFA dysfunction index, SF-36 and AOFAS hindfoot scores. Outcome measures were evaluated preoperative, 1 year postoperative, and at final follow up. Paired t-tests were performed to compare individual patients’ changes in PRO from preoperative to postoperative timepoints. Implant survivorship was evaluated as well as complications related to the index procedure. Implant survivorship based on need for complete revision of either the tibial or talar component Results: Twelve patients were included in the study. Average age at surgery was 28.5 years. Mean follow-up was 7.2 years. Mean VAS improved from 53.8 preoperatively to 14.7 (p= 0.152) at 1-year and 12.5 (p= 0.045) at final follow up, respectively. Mean SMFA improved from 40.0 preoperatively to 27.1 (p= 0.018) at 1-year and 24.0 (p= 0.006) at final follow up, respectively. SF-36 and AOFAS hindfoot scores also improved at 1 year and final follow-up compared to preoperative values [SF-36: 45.3 to 60.2 (p=0.06) and 67.0 (p=0.016); AOFAS: 40.6 to 70 (p= 0.08) and 68.9 (p=0.068)]. One patient required talar component revision due to aseptic loosening. One patient required subsequent removal of heterotopic bone due to impingement. No patients developed infection requiring surgical intervention. Conclusion: The onset of ankle arthritis typically occurs at a much younger age compared with that of the hip and knee and has a detrimental impact on patient quality of life. Despite a young age and increased activity demands, our results demonstrated that patients < 35 with end-stage ankle arthritis undergoing TAA demonstrated improved patient-reported outcomes greater than 2 years after surgery. Survivorship of TAA in our study was 91.7% at a mean follow-up of 7.2 years. We believe that TAA is a safe, effective and durable option for very young patients with high patient satisfaction at early to mid-term follow up