Radiation Dose during Digital Subtraction Angiography of the Brain-The Influence of Examination Parameters and Patient Factors on the Dose.

Cerebral vascular angiography, or digital subtraction angiography (DSA), is essential for diagnosing neurological conditions but poses radiation risks. This study aims to analyze the impact of examination parameters and patient characteristics on the radiation dose received during DSA to optimize safety and minimize exposure. A retrospective analysis of 251 DSA procedures using the GE Innova IGS 630 dual-plane instrument was conducted. Data on dose area product (DAP) and air kerma (KERMA), along with patient and examination details, were collected. Statistical analyses, including Mann-Whitney, Kruskal-Wallis, and Spearman rank correlation tests, assessed the relationships between variables and radiation dose outcomes. Significant correlations were found between the sides examined (left, right, or both) and DAP (p < 0.0001) and KERMA (p < 0.0001) values, with bilateral studies showing the highest values. The post hoc Dunn tests showed that the 'L + P' group significantly differs from both the right group (p < 0.0001 and the left group (p < 0.0001). There is no significant difference between the 'P' group and the 'L' group (p-value = 0.53). These results suggest that the right and left (both) group have unique KERMA mGy values compared to the other two groups. A strong correlation (rS = 0.87) existed between DAP and KERMA. The number of projections significantly impacted radiation dose (rS = 0.61). Tube parameters (kV and mA) and skull size had low correlations with DAP and KERMA. Optimizing imaging protocols and individualizing parameters can significantly enhance patient safety and diagnostic efficacy while also reducing occupational exposure for medical staff.

Lateral or Medial Parapatellar Surgical Approach to the Valgus Osteoarthritic Knee? A Retrospective Single-Center Study.

Aims: Total knee arthroplasty in patients with fixed valgus deformity is a demanding procedure. The aim of this study was to compare the clinical results of using the lateral approach [LA] versus the medial approach [MA] in the treatment of fixed valgus knee deformities. Methods: This single-center study compared the results of 143 consecutive patients with fixed valgus deformity (mean 21.55° valgus, mean age 68.2 years) undergoing LA Total Knee Arthroplasty [TKA] to 50 patients (mean 16.58° valgus, mean age 67.2 years) undergoing MA TKA. The mean follow-up period was 5.1 years (2−10 years). Data was collected from operative notes, routine postoperative visits, and radiological findings. Apart from a radiological evaluation, patients were clinically assessed both pre- and postoperatively using the Knee Society Score [KSS]. Descriptive statistics together with the Kolmogorov-Smirnov test, the Student's t-test for independent samples, and the Mann-Whitney U test were used. The level of significance in this study was α = 0.05. Results: In the LA group, the KSS Knee was significantly higher than in the MA group [85.31 vs. 77.42, respectively, p-value < 0.001]. The difference was also in the KSS total but with no statistical significance [155.17 vs. 149.22, p-value 0.087]. The surgery time in the LA group was shorter than in the MA group [81 vs. 91 min, respectively, p-value­0.002]. The complication rate after surgery was higher in the MA group than in the LA group (14% vs. 9%, respectively). Conclusions: The lateral approach is a good alternative to the standard medial parapatellar approach in the treatment of fixed valgus knee deformities. A higher postoperative KSS Knee, shorter surgery time, and similar complication rate make the lateral approach a valuable option for treating patients with osteoarthritis and fixed valgus knee deformity.

Shaft Fractures in Patients Requiring Primary or Revision Total Knee Arthroplasty Can Be Successfully Treated with Long-Stemmed Implants without Additional Fixation.

The aim of this study was to evaluate the bone union, complication rate, clinical and functional outcomes of long-stemmed total knee arthroplasty (TKA) in patients with periprosthetic femoral or tibial shaft fractures and in patients with femoral or tibial shaft fractures with coexisting advanced knee osteoarthritis (OA). This retrospective study comprised 25 patients who underwent surgery due to tibial or femoral shaft fractures: (1) with coexisting severe knee OA or (2) with a periprosthetic fracture requiring implant exchange. In all cases, fracture stabilization was performed intramedullary with the use of long-stemmed implants without the use of additional fixation material (plates, screws, or cerclage). Bone union was achieved in 22/25 patients (88%). One patient required revision with additional plate stabilization due to non-union, and asymptomatic partial bone union was observed in two cases. The group with periprosthetic fractures demonstrated good clinical (mean 73.1 ± 13.3) and moderate functional (mean 59.2 ± 18.8) outcomes in the Knee Society Scoring system (KSS). In the group with shaft fracture and coexisting OA significantly higher clinical (excellent results, mean 84.1 ± 11; p = 0.03) and functional (good results, mean 76.2 ± 20.6; p = 0.04) results were noted. There were no statistically significant differences in terms of range of motion (ROM) or complication rate between these two groups. One-stage TKA with a long-stemmed implant without the use of additional fixation material is an effective method for the treatment of femoral or tibial shaft fractures in patients who require joint replacement. Despite being technically demanding, the approach yields bone union and moderate to excellent clinical and functional outcomes with a relatively low complication rate.

The effects of testosterone replacement therapy in men with age-dependent hypogonadism on body composition, and serum levels of leptin, adiponectin, and C-reactive protein.

INTRODUCTION: Age-related hypogonadism in men leads to abnormal body composition development and overproduction of inflammatory cytokines, and thus has atherogenic and potentially cancer promoting effects. The aim of the study was to assess the effect of agedependent testosterone deficiency replacement in men on body composition, serum leptin, adiponectin, and C-reactive protein levels. MATERIAL AND METHODS: Men aged 50-65 years (56.0 ± 5.7, average ± SD), with total testosterone levels < 4 ng/mL, and clinical symptoms of hypogonadism were divided into two groups of 20 men and treated with testosterone (200 mg/two weeks intramuscularly) or placebo during 12 months. RESULTS: Twelve months of treatment with testosterone led to body mass index (BMI) and fat mass (FM) decrease from 26.6 ± 2.1 to 26.1 ± 1.8 kg/m², p < 0.05, and from 17.0 ± 4.4 to 15.6 ± 4.0 kg, p < 0.05, respectively. Body mass index and FM did not change in placebo-receiving subjects. Serum leptin and highly selective C-reactive protein (hsCRP) levels in testosterone group decreased from 6.2 ± 1.4 to 4.0 ± 1.2 µg/L, p < 0.05, and from 1.4 ± 1.2 to 1.0 ± 1.0 mg/L, p < 0.05 after 12 months, respectively. Adiponectin increased from 7.6 ± 2.5 µg/mL to 9.4 ± 2.8 µg/mL, p < 0.05 in the same time. In the placebo group serum leptin, adiponectin, and hsCRP levels did not change significantly. CONCLUSIONS: Testosterone replacement in men with age-related hypogonadism causes a decrease in body mass index, fat mass, serum leptin, and C-reactive protein levels and increases serum adiponectin levels.

Success Rates of Revision Knee Arthroplasty for Periprosthetic Joint Infection in Rheumatoid and Non-Rheumatoid Arthritis Patients.

This study evaluated the success and failure rates as well as the final results following 2-stage revision total knee arthroplasty (TKA) for periprosthetic joint infection (PJI). Particular emphasis was placed on comparing patients with rheumatoid arthritis (RA) and non-RA patients. A total of 140 knees that required 2-stage revision for PJI after TKA were analyzed. Mean patient age at first revision TKA was 67.9 years (range, 43 to 89 years), and mean time from second-stage revision to final follow-up was 53.3 months (range, 26 to 127 months). Thirty-eight of the 140 knees (27.1%) demonstrated recurrence of infection after first 2-stage revision. Of these, 8 required another 2-stage revision, 25 required knee arthrodesis, and 2 required amputation; 3 patients refused further treatment or were lost to follow-up. There was no recurrence of infection. No statistically significant differences were observed between the RA and non-RA groups in terms of success or failure rate (P=.6) according to Diaz-Ledezma and Knee Society Scores (P=.3). These findings indicate reinfection rates and final results were similar in RA and non-RA patients following revision TKA for PJI. [Orthopedics. 2019; 42(5):e472-e476.].

Neuromorphic silicon neuron circuits.

Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain-machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin-Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips.