Magnetic Resonance Imaging-based biomechanical simulation of cartilage: A systematic review.

MRI-based mathematical and computational modeling studies can contribute to a better understanding of the mechanisms governing cartilage's mechanical performance and cartilage disease. In addition, distinct modeling of cartilage is needed to optimize artificial cartilage production. These studies have opened up the prospect of further deepening our understanding of cartilage function. Furthermore, these studies reveal the initiation of an engineering-level approach to how cartilage disease affects material properties and cartilage function. Aimed at researchers in the field of MRI-based cartilage simulation, research articles pertinent to MRI-based cartilage modeling were identified, reviewed, and summarized systematically. Various MRI applications for cartilage modeling are highlighted, and the limitations of different constitutive models used are addressed. In addition, the clinical application of simulations and studied diseases are discussed. The paper's quality, based on the developed questionnaire, was assessed, and out of 79 reviewed papers, 34 papers were determined as high-quality. Due to the lack of the best constitutive models for various clinical conditions, researchers may consider the effect of constitutive material models on the cartilage disease simulation. In the future, research groups may incorporate various aspects of machine learning into constitutive models and MRI data extraction to further refine the study methodology. Moreover, researchers should strive for further reproducibility and rigorous model validation and verification, such as gait analysis.

General anesthesia in cesarean sections: a prospective review of 465 cesarean sections performed under general anesthesia.

BACKGROUND: In many countries, neuraxial blocks comprise the majority of anesthetics given for cesarean section. In Iran, however general anesthesia for cesarean section is prevalent. In our institution, the rate of general anesthesia for cesarean section is 39%, providing an opportunity to collect data regarding airway management in the parturients. We report on the outcomes of a series of patients who received general anesthesia for cesarean section. METHODS: A prospective observational study was conducted in two university hospitals, with approximately 5,500 deliveries annually. Demographics and airway characteristics were recorded. Eight potential risk factors for difficult intubation (short neck, obesity, facial edema, swollen tongue, receding mandible, and single, missing or protruding maxillary incisors) were analyzed. Then, laryngoscopic view, difficulty at intubation, and major complications were recorded. RESULTS: Data were obtained from 465 patients. There was a significant correlation between higher Mallampati score and both higher laryngoscopic view graded on the Cormack-Lehane system (P < 0.001) and difficulty at intubation (P-Value = 0.05). Emergency cesarean section was not associated with difficult intubation (P = 0.67). Multivariate analysis showed that receding mandible was the only potential risk factor for difficult tracheal intubation (P < 0.001) and removed short neck or protruding maxillary incisor which initially was powered as a risk factor by univariate analysis. A grade 3 laryngoscopic view was obtained in 15 cases (3.2%). There was no case of grade 4 view. There was only one failed intubation (0.2%), and 9 cases of very difficult intubation (1.9%). CONCLUSION: General anesthesia for cesarean section is safe with minimal risk.

Carrier frequency of SMA by quantitative analysis of the SMN1 deletion in the Iranian population.

BACKGROUND AND PURPOSE: Spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder. Carrier frequency studies of SMA have been reported for various populations. Although no large-scale population-based studies of SMA have been performed in Iran, previous estimates have indicated that the incidence of autosomal recessive disorder partly because of the high prevalence of consanguineous marriage is much higher in the Iranian population than in other populations. METHODS: In this study, we used a reliable and highly sensitive quantitative real-time PCR assay with SYBR green I dye to detect the copy number of the SMN1 gene to determine the carrier frequency of SMA in 200 healthy unrelated, non-consanguineous couples from different part of Iran. RESULTS: To validate the method in our samples, we determined the relative quantification (RQ) of patients with homozygous deletion (0.00) and hemyzygous carriers (0.29-0.55). The RQ in 10 of 200 normal individuals were within the carrier range of 0.31-0.57, estimating a carrier frequency of 5% in the Iranian population. CONCLUSIONS: Our data show that the SMA carrier frequency in Iran is higher than in the European population and that further programs of population carrier detection and prenatal testing should be implemented.

Influence of uterine exteriorization versus in situ repair on post-Cesarean maternal pain: a randomized trial.

BACKGROUND: This study was done to compare post-cesarean delivery pain associated with routine exteriorization of the uterus versus in situ uterine repair in the puerperium. METHODS: This prospective study included 206 women who underwent cesarean delivery under general anesthesia and who were randomly assigned to two groups based on the site of uterine repair: exteriorized uterine repair (102 women) versus in situ uterine repair (104 women). Exclusion criteria were neuraxial blockade and patient refusal to participate. Visceral and incisional pain was assessed on the first and second postoperative nights using a visual analog score of 0-100 mm. RESULTS: There were no significant differences between the groups in maternal age, weight, gestational age, race, preoperative hemoglobin or gravidity. All subjects underwent general anesthesia and had a low transverse incision of the uterus. Exteriorization was associated with higher postoperative visceral pain scores: first night 66.7 vs. 43.5 (P<0.001); second night 44.6 vs. 23.9 (P<0.001). The incidence of postoperative fever and wound infection, postoperative hemoglobin and duration of hospital stay were similar between groups. CONCLUSION: Exteriorization of the uterus for repair of the uterine incision increases the first- and second-night postoperative pain significantly in women undergoing cesarean section.

Abnormal viscoelastic behaviour of passive ankle joint movement in diabetic patients: an early or a late complication?

AIMS/HYPOTHESIS: The goal of the present study was to compare the range of motion and both the viscous and elastic components of passive ankle joint movement in short- and long-term diabetic patients with that of a control population. METHODS: Thirty-four diabetic patients and 16 control subjects entered into the study. Patients with a history of over 15 years of diabetes were considered as a long-term diabetic group. In order to quantify the passive ankle joint movement, a device was designed to measure the dorsi- and plantar-flexion angle and the net moment at the ankle. Elastic behaviour was examined as the separate slope of regression lines (stiffness) of plantar and dorsal components in the loading moment-angle curve. It was also examined as the slope of the regression line in the final 10% of each component. Hysteresis, a characteristic of viscoelastic materials that indicates loss of energy during unloading, was corrected for range of motion and used to examine viscous behaviour of the ankle joint. RESULTS: Total and plantar ranges of motion were significantly lower in long-term diabetic patients than in short-term diabetic and control groups (p < 0.05). Plantar-flexion stiffness was significantly lower in short-term diabetic patients than in control subjects and long-term diabetic groups (p < 0.05). Corrected hysteresis was significantly higher in long-term diabetic than in short-term diabetic and control (p < 0.05) groups in the dorsal range of motion. CONCLUSIONS/INTERPRETATION: This study shows that both decreased plantar and total ankle joint ranges of motion, and increased viscous component of passive ankle joint movement are among the late complications of diabetes.