Ultra-low-dose unenhanced chest CT: Prospective comparison of high kV/low mA versus low kV/high mA protocols

Purpose

To qualitatively and quantitatively compare unenhanced ultra-low-dose chest computed tomography (ULD-CT) acquired at 80 kVp and 135 kVp.

Predictors of return to desired activity 12 months following unicompartmental and total knee arthroplasty

Background and purpose — 1 in 5 patients are dissatisfied following unicompartmental or total knee arthroplasty (UKA or TKA). This may be partly explained by failing to return to desired activity post-arthroplasty. To facilitate return to desired activity, a greater understanding of predictors of return to desired activity in UKA and TKA patients is needed. We compared rates of return to desired activity 12 months following UKA vs. TKA, and identified and compared predictors of return to desired activity 12 months following UKA vs. TKA.

Patients and methods — Patients were prospectively recruited from 2 hospitals prior to undergoing UKA or primary TKA. Patients reported preoperatively the activity/activities that were limited due to their knee that they wished to return to after arthroplasty. At 12-months postoperatively, patients reported whether they had returned to these activities (‘return to desired activity’). Preoperative predictors evaluated were age, sex, BMI, education, comorbidities, pain expectations, Oxford Knee Score (OKS), UCLA Activity Score, and EQ-5D. Generalized linear models assessed the relationship between potential predictors and return-to-desired-activity.

Results — The response rate of all patients eligible for 12-month follow-up was 74%. TKA patients (n = 575) were older (mean (SD) 70 (9) vs. 67 (10)) with a greater BMI (31 (6) vs. 30 (5)) than patients undergoing UKA (n = 420). 75% of UKA and 59% of TKA patients returned to desired activity. TKA patients had a greater risk of non-return to desired activity than patients undergoing UKA (risk ratio (95% CI) 1.5 (1.2–1.8)). Predictors of non-return to desired activity following UKA were worse OKS (0.96 (0.93–0.99)), higher BMI (1.04 (1.01–1.08)), and worse expectations (1.9 (1.2–2.8)). Predictors of non-return to desired activity following TKA were worse EQ-5D (0.53 (0.33–0.85)) and worse OKS (0.98 (0.96–1.0)).

Interpretation — UKA patients were more likely to return to desired activity than TKA patients. Predictors of return to desired activity differed following UKA and TKA. Optimizing selection of arthroplasty procedure based on patient characteristics and targeting predictors of poor outcome may facilitate return to desired activity with potential to enhance postoperative satisfaction.     

Not all cemented hips are the same: a register-based (NJR) comparison of taper-slip and composite beam femoral stems

Background and purpose — No difference in outcome has been demonstrated comparing cemented taper-slip and composite beam designs in short-term randomised trials; we assessed outcome differences using a registry analysis.

Patients and methods — All cemented stems with > 100 implantations were identified in the National Joint Registry of England and Wales from April 1, 2003 to September 31, 2013 and categorised as taper-slip or composite beam. Survival analyses using Kaplan–Meier and Cox regression were performed.

Results — We identified 292,987 cemented arthroplasties, of which 16% (47,586) were composite beam stems, with taper-slip stems making up the remainder (n = 245,401). There was a statistically significant increased chance of revision in the composite beam group compared with the taper-slip group (1.7% vs 1.3%, p < 0.001) but statistically no significant differences of survival estimates (p = 0.06). When the 2 groups were segregated to delineate the most implanted model in each category, the differences became more profound with the most implanted taper-slip stem (Exeter V40) showing statistically and clinically significant superior 8-year survival: 97.9% compared with 97.6% for all other taper-slip; 97.5% for the most implanted composite beam (Charnley cemented stem); and 97.7% for all other composite beam.

Interpretation — There was an increased incidence of revision for composite beam stems. The most implanted taper-slip stem demonstrated significant survival advantage vs. all other stems.     

The Effect of Donor- and Recipient-Related Factors on Corneal Graft Survival in Penetrating Keratoplasty

Purpose: To investigate the impact of donor and recipient factors on graft survival in penetrating keratoplasty (PK).

Material and Methods: This retrospective study included 365 eyes that underwent PK using corneas from 231 donors between June 2010 and June 2015. Patients were divided into three groups (group 1: primary endothelial diseases; group 2: iatrogenic endothelial disorders; and group 3: other pathologies with a healthy endothelium) according to PK indications. The primary outcome measure was corneal graft survival at the last visit (clear or opaque). Graft clarity was assessed using Kaplan–Meier survival analysis.

Results: The most frequent PK indication was keratoconus (KC) (20.5%) followed by pseudophakic bullous keratopathy (PBK) (18.9%). Donor age had a negative impact on endothelial cell density (ECD) measured by an eye bank specular microscope (p < 0.001). Median best-corrected visual acuity in logarithm of the minimum angle of resolution units increased from 2.1 to 0.8 at 1 year after PK (p < 0.001). The clear graft rate was 96.7% at year 1, 88.8% at year 2, and 85.5% at year 3. Overall graft survival was 84.9% during a median of 39 months (range: 24–79 months) of follow-up. A higher graft survival rate (67.2%) was observed in KC compared to PBK during 6 years (p < 0.001). Recipients younger than 50 years of age showed a better graft survival rate than those older than 70 years of age (p = 0.037). Donor ECD, time between excision and death, and preservation time had no significant effect on graft survival. Frequent graft rejection episodes (GREs) and additional procedures during surgery had a negative impact on graft survival (p < 0.001 and p = 0.014, respectively). A worse graft survival was observed in group 2 compared to groups 1 and 3 (p = 0.042).

Conclusions: Young recipient age and KC were associated with a better graft survival. Graft endothelial density and preservation time had no impact on graft survival. PBK, low vision at baseline and year 1, frequent GREs, and additional interventions during surgery had a negative impact on graft survivals.     

Differentiated Thyroid Cancer in Children: A UK Multicentre Review and Review of the Literature

Aims

To obtain an overview of the management and outcomes of children aged 18 years or younger diagnosed with differentiated thyroid carcinoma of follicular cell origin across the UK, by collecting and analysing data from the limited number of centres treating these patients. This multicentre data might provide a more realistic perspective than single-institution series.

Prediction modelling using routine clinical parameters to stratify survival in Malignant Pleural Mesothelioma patients undergoing cytoreductive surgery

Introduction

Malignant pleural mesothelioma (MPM) is an uncommon cancer with a poor prognosis and heterogeneous survival. Surgery for MPM is offered in some specialist centers to highly selected patients. A previously described classification and regression tree (CART) model stratified survival in unselected MPM patients using routinely collected clinical data. This study aimed to examine the performance of this CART model on a highly selected surgical population.

locStra: Fast analysis of regional/global stratification in whole‐genome sequencing studies

locStra is an ‐package for the analysis of regional and global population stratification in whole‐genome sequencing (WGS) studies, where regional stratification refers to the substructure defined by the loci in a particular region on the genome. Population substructure can be assessed based on the genetic covariance matrix, the genomic relationship matrix, and the unweighted/weighted genetic Jaccard similarity matrix. Using a sliding window approach, the regional similarity matrices are compared with the global ones, based on user‐defined window sizes and metrics, for example, the correlation between regional and global eigenvectors. An algorithm for the specification of the window size is provided. As the implementation fully exploits sparse matrix algebra and is written in C++, the analysis is highly efficient. Even on single cores, for realistic study sizes (several thousand subjects, several million rare variants per subject), the runtime for the genome‐wide computation of all regional similarity matrices does typically not exceed one hour, enabling an unprecedented investigation of regional stratification across the entire genome. The package is applied to three WGS studies, illustrating the varying patterns of regional substructure across the genome and its beneficial effects on association testing.     

Midterm Outcomes of the Dissected Aorta Repair Through Stent Implantation Trial

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Exercise training‐induced visceral fat loss in obese women: The role of training intensity and modality

Visceral fat loss in response to four‐cycle ergometer training regimens with explicit differences in exercise intensity and modality was compared. Fifty‐nine obese young women (body fat percentage ≥ 30%) were randomized to a 12‐week intervention consisting of either all‐out sprint interval training (SIT_all‐out, n = 11); supramaximal SIT (SIT₁₂₀, 120% O_2peak, n = 12); high‐intensity interval training (HIIT₉₀, 90% O_2peak, n = 12), moderate‐intensity continuous training (MICT, 60% O_2peak, n = 11), or no training (CON, n = 13). The total work done per training session in SIT₁₂₀, HIIT₉₀, and MICT was confined to 200 kJ, while it was deliberately lower in SIT_all‐out. The abdominal visceral fat area (AVFA) was measured through computed tomography scans. The whole‐body and regional fat mass were assessed through dual‐energy X‐ray absorptiometry. Pre‐, post‐, and 3‐hour post‐exercise serum growth hormone (GH), and epinephrine (EPI) were measured during selected training sessions. Following the intervention, similar reductions in whole‐body and regional fat mass were found in all intervention groups, while the reductions in AVFA resulting from SIT_all‐out, SIT₁₂₀, and HIIT₉₀ (>15 cm²) were greater in comparison with MICT (<3.5 cm², P < .05). The AVFA reductions among the SITs and HIIT groups were similar, and it was concomitant with the similar exercise‐induced releases of serum GH and EPI. CON variables were unchanged. These findings suggest that visceral fat loss induced by interval training at or above 90% O_2peak appeared unresponsive to the change in training intensity. Nonetheless, SIT_all‐out is still the most time‐efficient strategy among the four exercise‐training regimes for controlling visceral obesity.