HR-pQCT cross-calibration using standard vs. Laplace-Hamming binarization approach.

High-resolution peripheral quantitative computed tomography (HR-pQCT) has emerged as a powerful imaging technique for characterizing bone microarchitecture in the human peripheral skeleton. The second-generation HR-pQCT scanner provides improved spatial resolution and a shorter scan time. However, the transition from the first-generation (XCTI) to second-generation HR-pQCT scanners (XCTII) poses challenges for longitudinal studies, multi-center trials, and comparison to historical data. Cross-calibration, an established approach for determining relationships between measurements obtained from different devices, can bridge this gap and enable the utilization and comparison of legacy data. The goal of this study was to establish cross-calibration equations to estimate XCTII measurements from XCTI data, using both the standard and Laplace-Hamming (LH) binarization approaches. Thirty-six volunteers (26-85 yr) were recruited and their radii and tibiae were scanned on both XCTI and XCTII scanners. XCTI images were analyzed using the manufacturer's standard protocol. XCTII images were analyzed twice: using the manufacturer's standard protocol and the LH segmentation approach previously developed and validated by our team. Linear regression analysis was used to establish cross-calibration equations. Results demonstrated strong correlations between XCTI and XCTII density and geometry outcomes. For most microstructural outcomes, although there were considerable differences in absolute values, correlations between measurements obtained from different scanners were strong, allowing for accurate cross-calibration estimations. For some microstructural outcomes with a higher sensitivity to spatial resolution (eg, trabecular thickness, cortical pore diameter), XCTII standard protocol resulted in poor correlations between the scanners, while our LH approach improved these correlations and decreased the difference in absolute values and the proportional bias for other measurements. For these reasons and due to the improved accuracy of our LH approach compared with the standard approach, as established in our previous study, we propose that investigators should use the LH approach for analyzing XCTII scans, particularly when comparing to XCTI data.

Assessment of Epidemiology and Clinical Profile of Psoriatic Arthritis Patients in India.

BACKGROUND: Psoriasis is an inflammatory skin disease associated with significant comorbidity. However, the characteristics of patients with psoriasis are not well documented in India, and a more detailed understanding is needed to delineate the epidemiologic profile at the regional level for better management of psoriasis. Herein, we reported the clinical profile and demographic pattern of psoriasis to further understand its burden in the Indian setting. METHODS: We conducted a retrospective observational study of patients diagnosed with psoriasis who fulfilled the classification criteria for psoriatic arthritis (CASPAR) criteria. Patients were included from the rheumatology outpatient department of Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute in Mumbai, India. The outcomes included demographic and clinical profiles, patterns of joint involvement, and comorbidities associated with psoriasis. A p-value of <0.05 was considered significant. RESULTS: We enrolled 60 patients, with a mean age of 50.87 years and a higher proportion of females (62%). The majority of patients with less than five joints had associated comorbidities (40 out of 60). Psoriatic arthritis (PsA) occurred in 41 patients [mean ± standard deviation (SD) age of onset-38.88 ± 13.24 years], with the highest occurrence in the 30-50 years (53.3%). The majority of patients with PsA developed it within 2 to ≥5 years of psoriasis occurrence. We did not find any significant correlation between the occurrence of PsA and comorbidities, as well as the duration of PsA and the number of joints (p = 0.152). Pitting and enthesitis were the most common morphological changes noted in almost half of the patients. CONCLUSION: Our study provides an overview of the epidemiologic and clinical characteristics of psoriasis patients in India. These findings could be useful for early diagnosis of PsA and help clinicians in assessing the progression of psoriasis into PsA.

Retrospective cohort study analyzing outcomes of the SIGN Fin Nail in adult femoral fractures using the retrograde approach.

Purpose: There is high burden of long bone fractures in low- and middle-income countries (LMICs). Given a limited availability of fluoroscopy in LMICs, the Surgical Implant Generation Network (SIGN) developed two types of intramedullary nails: the SIGN standard nail and the SIGN Fin Nail. A limited number of studies have analyzed healing outcomes with the SIGN Fin Nail and the current study is the largest one to date. The purpose of this study is to compare outcomes between the SIGN standard nail and SIGN Fin Nails in adult femoral shaft fractures treated with a retrograde approach. Method: A retrospective cohort study of adults with femoral shaft fractures was performed using the Sign Online Surgical Database (SOSD). The primary outcome was achieving full painless weight bearing and the secondary outcomes assessed were radiographic healing and infection. A propensity-score adjustment was performed for potential confounders and effect modification due to fracture location was tested using a Mantel-Haenszel test for heterogeneity. Results: Of 19,928 adults with femoral shaft fractures, 2,912 (14.7%) had the required 6-month follow-up to be included. The overall propensity score weighted relative risk between the Fin and Standard Nail for achieving painless weight-bearing was 0.99, 95% CI [0.96-1.03] and for radiographical healing was 0.99, 95%CI [0.97-1.02]. The propensity score weighted relative risk for infection was 1.30, 95% [0.85-1.97]. Use of the Fin nail was also significantly associated with shorter surgery times (p < 0.005, effect size = 24 min). Sub-group analysis based on fracture location and injury cause demonstrated no change in relative risk. Conclusion: The Fin nail showed no change in relative risk in terms of achieving full painless weightbearing or radiographic healing compared to the standard nail for retrograde nailing of femoral shaft fractures in adults. The heterogeneous nature of the cohort and large sample size allow for generalizability and add to a growing base of literature supporting use of the Fin Nail for retrograde femoral nailing. However, there are limitations as we could not correct for comminution at the fracture site or measure radiographic alignment or shortening.

Delays in Debridement of Open Femoral and Tibial Fractures Increase Risk of Infection.

BACKGROUND: Infection remains a costly, devastating complication following the treatment of open fractures. The appropriate timing of debridement is controversial, and available evidence has been conflicting. METHODS: This study is a retrospective analysis of the SIGN (Surgical Implant Generation Network) Surgical Database (SSDB), a prospective registry of fracture cases in predominantly low-resource settings. Skeletally mature patients (≥16 years of age) who returned for follow-up at any time point after intramedullary nailing of an open femoral or tibial fracture were included. Patients were excluded if they had delays in debridement exceeding 7 days after the injury. Utilizing a model adjusting for potential confounders, including patient demographic characteristics, injury characteristics, country income level, and hospital type and resources, local logistic regression analysis was performed to evaluate the probability of infection with increasing time to debridement in 6-hour increments. RESULTS: In this study, 27.3% of patients met the eligibility criteria and returned for follow-up, with a total of 10,651 fractures from 61 countries included. Overall, the probability of infection increased by 0.17% for every 6-hour delay in debridement. On subgroup analysis, the probability of infection increased by 0.23% every 6 hours for Gustilo-Anderson type-III injuries compared with 0.13% for Gustilo-Anderson type-I or II injuries. The infection risk increased every 6 hours by 0.18% for tibial fractures compared with 0.13% for femoral fractures. CONCLUSIONS: There was a linear and cumulative increased risk of infection with delays in debridement for open femoral and tibial fractures. Such injuries should be debrided promptly and expeditiously. The size and international nature of this cohort make these findings uniquely generalizable to nearly all environments where such injuries are treated. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

A Laplace-Hamming Binarization Approach for Second-Generation HR-pQCT Rescues Fine Feature Segmentation.

Although second-generation high-resolution peripheral quantitative computed tomography (XCTII) provides the highest-resolution in vivo bone microstructure assessment, the manufacturer's standard image processing protocol omits fine features in both trabecular and cortical compartments. To optimize fine structure segmentation, we implemented a binarization approach based on a Laplace-Hamming (LH) segmentation and documented the reproducibility and accuracy of XCTII structure segmentation using both the standard Gaussian-based binarization and the proposed LH segmentation approach. To evaluate reproducibility, 20 volunteers (9 women, 11 men; aged 23-75 years) were recruited, and three repeat scans of the radii and tibias were acquired using the manufacturer's standard in vivo protocol. To evaluate accuracy, cadaveric structure phantoms (14 radii, 6 tibias) were scanned on XCTII using the same standard in vivo protocol and on µCT at 24.5 µm resolution. XCTII images were analyzed twice-first, with the manufacturer's standard patient evaluation protocol and, second, with the proposed LH segmentation approach. The LH approach rescued fine features evident in the grayscale images but omitted or overrepresented (thickened) by the standard approach. The LH approach significantly reduced error in trabecular volume fraction (BV/TV) and thickness (Tb.Th) compared with the standard approach; however, higher error was introduced for trabecular separation (Tb.Sp). The LH approach improved the correlation between XCTII and µCT for cortical porosity (Ct.Po) and significantly reduced error in cortical pore diameter (Ct.Po.Dm) compared with the standard approach. The LH approach resulted in improved precision compared with the standard approach for BV/TV, Tb.Th, Ct.Po, and Ct.Po.Dm at the radius and for Ct.Po at the tibia. Our results suggest that the proposed LH approach produces substantially improved binary masks, reduces proportional bias, and provides greater accuracy and reproducibility in important outcome metrics, all due to more accurate segmentation of the fine features in both trabecular and cortical compartments. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Synthesis and characterization of sodium vanadium oxide gels: the effects of water (n) and sodium (x) content on the electrochemistry of Na(x)V2O5·nH2O.

Sodium vanadium oxide gels, Na(x)V(2)O(5)·nH(2)O, of varying sodium content (0.12 < x < 0.32) were prepared by careful control of an ion exchange process. The water content (0.23 > n > 0.01) and interlayer spacing were found to be inversely proportional to the sodium level (x), thus control of sodium (x) content provided a direct, chimie douce approach for control of hydration level (n) and interlayer spacing, without the need for high temperature treatment to affect dehydration. Notably, the use of high temperatures to modify hydration levels can result in crystallization and collapse of the interlayer structure, highlighting the distinct advantage of our novel chimie douce synthesis strategy. Subsequent to synthesis and characterization, results from an electrochemical study of a series of Na(x)V(2)O(5)·nH(2)O samples highlight the significant impact of interlayer water on delivered capacity of the layered materials. Specifically, the sodium vanadium oxide gels with higher sodium content and lower water content provided higher capacities in lithium based cells, where capacity delivered to 2.0 V under C/20 discharge ranged from 170 mAh/g for Na(0.12)V(2)O(5)·0.23H(2)O to 300 mAh/g for Na(0.32)V(2)O(5)·0.01H(2)O. The capacity differences were maintained as the cells were cycled.