Phase-contrast virtual chest radiography.

Respiratory X-ray imaging enhanced by phase contrast has shown improved airway visualization in animal models. Limitations in current X-ray technology have nevertheless hindered clinical translation, leaving the potential clinical impact an open question. Here, we explore phase-contrast chest radiography in a realistic in silico framework. Specifically, we use preprocessed virtual patients to generate in silico chest radiographs by Fresnel-diffraction simulations of X-ray wave propagation. Following a reader study conducted with clinical radiologists, we predict that phase-contrast edge enhancement will have a negligible impact on improving solitary pulmonary nodule detection (6 to 20 mm). However, edge enhancement of bronchial walls visualizes small airways (< 2 mm), which are invisible in conventional radiography. Our results show that phase-contrast chest radiography could play a future role in observing small-airway obstruction (e.g., relevant for asthma or early-stage chronic obstructive pulmonary disease), which cannot be directly visualized using current clinical methods, thereby motivating the experimental development needed for clinical translation. Finally, we discuss quantitative requirements on distances and X-ray source/detector specifications for clinical implementation of phase-contrast chest radiography.

The development of musculoskeletal radiology for 100 years as presented in the pages of Acta Radiologica.

During the last 100 years, musculoskeletal radiology has developed from bone-only radiography performed by everyone to a dedicated subspecialty, still secure in its origins in radiography but having expanded into all modalities of imaging. Like other subspecialties in radiology, it has become heavily dependent on cross-sectional and functional imaging, and musculoskeletal interventions play an important role in tumor diagnosis and treatment and in joint diseases. All these developments are reflected in the pages in Acta Radiologica, as shown in this review.

Does body mass index affect restoration of femoral offset, leg length and cup positioning after total hip arthroplasty? A prospective cohort study.

BACKGROUND: In obese patients, total hip arthroplasty (THA) can be technically demanding with increased perioperative risks. The aim of this prospective cohort study is to evaluate the effect of body mass index (BMI) on radiological restoration of femoral offset (FO) and leg length as well as acetabular cup positioning. METHODS: In this prospective study, patients with unilateral primary osteoarthritis (OA) treated with THA between September 2010 and December 2013 were considered for inclusion. The perioperative plain radiographs were standardised and used to measure the preoperative degree of hip osteoarthritis, postoperative FO, leg length discrepancy (LLD), acetabular component inclination and anteversion. RESULTS: We included 213 patients (74.5% of those considered for inclusion) with a mean BMI of 27.7 (SD 4.5) in the final analysis. The postoperative FO was improper in 55% and the LLD in 15%, while the cup inclination and anteversion were improper in 13 and 23% of patients respectively. A multivariable logistic regression model identified BMI as the only factor that affected LLD. Increased BMI increased the risk of LLD (OR 1.14, 95% CI 1.04 to 1.25). No other factors included in the model affected any of the primary or secondary outcomes. CONCLUSION: Increased BMI showed a negative effect on restoration of post-THA leg length but not on restoration of FO or positioning of the acetabular cup. Age, gender, OA duration or radiological severity and surgeon's experience showed no relation to post-THA restoration of FO, leg length or cup positioning.

The Influence of Radiological Severity and Symptom Duration of Osteoarthritis on Postoperative Outcome After Total Hip Arthroplasty: A Prospective Cohort Study.

BACKGROUND: We aimed to investigate the influence of preoperative radiological severity and symptom duration of hip osteoarthritis (OA) on the postoperative functional outcome, quality of life, as well as abductor muscle strength after total hip arthroplasty (THA). METHODS: In this prospective cohort study, we studied 250 patients. Preoperatively, we evaluated the function with the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and quality of life with euroqol-5D (EQ-5D). At 1 year after THA, the same scores and also hip abductor muscle strength were measured in 222 patients. We divided the cohort twice, first according to the radiological OA severity [Kellgren-Lawrence classification (KL)] and then according to the OA symptom duration. We investigated whether the preoperative KL class and symptom duration influenced the 1-year WOMAC (primary outcome measure) or EQ-5D and abductor muscle strength (secondary outcome measures). RESULTS: The crude results showed that KL class and symptom duration had no influence (P = .90 and P = .20, respectively) on the 1-year WOMAC. Younger age, male gender, and lower body mass index were associated with a better function. Regarding 1-year EQ-5D, the crude results showed that body mass index and KL class had no influence (P = .83 and P = .39, respectively). The adjusted results showed that only age and gender influenced the postoperative EQ-5D. No influence of the tested factors was found on the 1-year abductor muscle strength. CONCLUSION: Preoperative radiological OA severity and symptom duration had no influence on the outcome of THA and should probably not affect the decision about timing the operative intervention.

Leg lengthening and femoral-offset reduction after total hip arthroplasty: where is the problem - stem or cup positioning?

Background Restoration of femoral offset (FO) and leg length is an important goal in total hip arthroplasty (THA) as it improves functional outcome. Purpose To analyze whether the problem of postoperative leg lengthening and FO reduction is related to the femoral stem or acetabular cup positioning or both. Material and Methods Between September 2010 and April 2013, 172 patients with unilateral primary osteoarthritis treated with THA were included. Postoperative leg-length discrepancy (LLD) and global FO (summation of cup and FO) were measured by two observers using a standardized protocol for evaluation of antero-posterior plain hip radiographs. Patients with postoperative leg lengthening ≥10 mm (n = 41) or with reduced global FO >5 mm (n = 58) were further studied by comparing the stem and cup length of the operated side with the contralateral side in the lengthening group, and by comparing the stem and cup offset of the operated side with the contralateral side in the FO reduction group. We evaluated also the inter-observer and intra-observer reliability of the radiological measurements. Results Both observers found that leg lengthening was related to the stem positioning while FO reduction was related to the positioning of both the femoral stem and acetabular cup. Both inter-observer reliability and intra-observer reproducibility were moderate to excellent (intra-class correlation co-efficient, ICC ≥0.69). Conclusion Post THA leg lengthening was mainly caused by improper femoral stem positioning while global FO reduction resulted from improper positioning of both the femoral stem and the acetabular cup.

Validity, reliability and reproducibility of plain radiographic measurements after total hip arthroplasty.

BACKGROUND: In total hip arthroplasty (THA), radiographic preoperative planning and postoperative evaluation of acetabular component, femoral offset (FO) and leg length discrepancy (LLD) require good validity, interobserver reliability and intraobserver reproducibility. In this study, we evaluated the validity of the Sundsvall method of FO measurement and the interobserver reliability and intraobserver reproducibility of measurement of FO, LLD, acetabular cup inclination and anteversion. MATERIAL AND METHODS: Ninety patients with primary unilateral osteoarthritis (OA) were included in this prospective study. On postoperative radiographs FO by the Sundsvall method (femoral axis-pelvic midline), FO by a standard method (femoral axis-hip rotational centre-teardrop point), LLD (inter-teardrop line-lesser trochanter), acetabular cup inclination (on AP view the angle between the cup rim and transischial line) and anteversion (on lateral view the angle between the face of acetabulum and a line perpendicular to the horizontal plane) were measured. The interobserver reliability and intraobserver reproducibility were calculated for three independent observers. The concurrent validity and degree of prediction of the Sundsvall method are measured by comparing its results with the standard method. RESULTS: The interobserver reliability of all measurements was excellent (ICC >0.80), except for LLD, which was substantial (ICC = 0.79). The intraobserver reproducibility of all measurements was excellent (ICC > 0.80). The concurrent validity of the Sundsvall method compared to the standard method was good with a positive correlation. CONCLUSION: The Sundsvall method is as reliable as the standard method. The evaluated radiographic measurement methods have the required validity and reliability to be used in clinical practice.

Measurement of leg length discrepancy after total hip arthroplasty. The reliability of a plain radiographic method compared to CT-scanogram.

OBJECTIVE: To measure the interobserver reliability and intraobserver reproducibility of post total hip arthroplasty (THA) leg length discrepancy (LLD) measurement on radiographs as well as to evaluate its accuracy by comparing it with LLD measurement on computed tomographic scanogram (CT-scanogram). MATERIALS AND METHODS: In this prospective study, postoperative LLD measurements in ten THA patients were made by four observers on anteroposterior radiographs of the pelvis (inter-teardrop line to the tip of lesser trochanter) and compared to LLD measurements made on CT-scanogram scout views of the lower limb. Two observers repeated the LLD measurements on radiographs 8 weeks after the first measurements. The interobserver reliability of the LLD measurement on plain radiographs was evaluated by comparing the measurements of the four observers and the intraobserver reproducibility by comparing the two repeated measurements made by the two observers. RESULTS: We found excellent interobserver reliability (mean ICC 0.83) and intraobserver reproducibility (ICC 0.90 and 0.88) of the LLD measurements on plain radiographs. There was a moderate to excellent agreement, but with wide variation of measurements among the four observers, when plain radiographic measurement was compared with CT-scanogram (ICC 0.58, 0.60, 0.71, and 0.82). CONCLUSION: Despite the excellent interobserver reliability and intraobserver reproducibility of LLD measurement on radiographs, clinicians should be aware of its limited accuracy when compared to CT-scanogram.

Kinesiophobia and its association with functional outcome and quality of life 6-8 years after total hip arthroplasty.

OBJECTIVE: The aim of this study was to assess the incidence and severity of kinesiophobia, and to determine the relationship between Tampa Scale of Kinesiophobia (TSK) scores, functional outcome and quality of life (QoL) 6-8 years after Total Hip Arthroplasty (THA). METHODS: 161 patients (78 male and 83 female) with unilateral primary osteoarthritis (OA) treated with THA between September 2010 and December 2013 were included in this study. Western Ontario and McMaster Universities Osteoarthritis (WOMAC) and EQ-5D scores were measured preoperatively. At 6-8 years follow-up, these scores were repeated and TSK scores were also measured. According to the TSK, patients were divided into two groups for further comparisons and analysis: without kinesiophobia (TSK-score ≤ 36) and with kinesiophobia (TSK-score >36). RESULTS: There were 99 patients (61.5%) with no kinesiophobia (TSK score ≤ 36, TSK mean 28.4, SD 4.7) and 62 patients (38.5%) with kinesiophobia (TSK score > 36, TSK mean 42.8, SD 5.3). Patients with and without kinesiophobia were not statistically different regarding age, sex or body mass index. (P = 0.20, P = 0.99, P = 0.22, respectively). In the group with no kinesiophobia, the mean 6-8 years WOMAC was 12.4 (SD 15.6), while the absolute delta (Δ) value between preoperative and 6-8 years WOMAC was 46.2 (SD 20.4), compared to the group with kinesiophobia where the mean 6-8 years WOMAC was 32.2 (SD 23.4), while the absolute delta (Δ) value between preoperative and 6-8 years WOMAC was 32.3 (SD 25.5): both P < 0.001. The group with no kinesiophobia had a mean 6-8 years EQ-5D of 0.81 (SD 0.22), while the absolute delta (Δ) value between preoperative and 6-8 years EQ-5D was 0.44 (SD 0.26), compared to the group with kinesiophobia where the mean 6-8 years EQ-5D was 0.57 (SD 0.23), while the absolute delta (Δ) value between preoperative and 6-8 years EQ-5D was 0.33 (SD 0.26): P < 0.001 and P = 0.03, respectively. TSK scores were associated with worse WOMAC and EQ-5D scores, higher proportion of dependence on walking aids and increased THArelated adverse events (all P < 0.05). CONCLUSION: This study has shown us that there is a high incidence of kinesiophobia 6-8 years after surgery and treating kinesiophobia early after THA might improve the outcome. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.

The Association of On-Admission Blood Hemoglobin, C-Reactive Protein, and Serum Creatinine With 2-Year Mortality of Patients With Femoral Neck Fractures.

INTRODUCTION: The mortality of femoral neck fracture (FNF) is high and every effort should be made to identify and manage any possible risk factors. The aim of this study was to evaluate whether on-admission hemoglobin (Hb) level, C-reactive protein (CRP), and serum creatinine were associated with 2-year mortality after FNF. PATIENTS AND METHODS: In this retrospective observational cohort study, we considered for inclusion all displaced FNF patients 65 years and above treated with hemi-arthroplasty between February 2011 and May 2015. We documented the age, sex, cognitive status, and American Society of Anesthesiologists (ASA) classification. The Hb level, CRP, and serum creatinine were measured. The medical records were followed up for 2 years. We fitted different crude and adjusted Cox proportional hazards models to examine whether Hb level <100 g/L, CRP >20 mg/L, and serum creatinine >100 µmol/L were associated with the 2-year mortality, adjusted for age, sex, and ASA class. RESULTS: A total of 290 patients [208 females (72%), mean age 84 years] were included in the study. More than 50% of patients had impaired cognition and ASA class 3-4. Of the 290 patients, 38.3% (n = 111) had died within 2 years after surgery. Mortality among males was 46.3% (n = 38) while mortality among females was 35,1% (n = 73), p = 0.07. We found that on-admission Hb level <100 g/L was associated with 2-year mortality (HR = 3.3, 95% CI: 1.3-8.3, p < 0.01) while CRP >20 mg/L and serum creatinine >100 µmol/L were not associated with 2-year mortality (p = 0.89 and p = 0.31, respectively). CONCLUSION: On-admission Hb level <100 g/L, but not CRP >20 mg/L and serum creatinine >100 µmol/L, was associated with 2-year mortality. These results can help healthcare providers identify high-risk FNF patients who probably would benefit from optimized perioperative medical management.