EXPERIMENTAL STUDY ON THE EFFECTIVENESS OF AN ENERGY DISSIPATION CONFIGURATION IN AN OPEN CHANNEL OF STEEP SLOPE

Στην παρούσα εργασία μελετάται πειραματικά η ροή σε σήραγγα υπό συνθήκες ελεύθερης επιφάνειας και έντονης κλίσης πυθμένα 1:10. Διερευνάται η δυνατότητα μείωσης της ταχύτητας ροής μέσω συνδυασμού κατακόρυφων, πλευρικών στοιχείων τραχύτητας και λεκανών καταστροφής ενέργειας με οδοντώσεις. Η μελετώμενη διάταξη στηρίζεται στην ύπαρξη επαναλαμβανομένων τμημάτων (modules) εντός των οποίων επιτυγχάνεται επαναληψιμότητα της ροής. Η αποτελεσματικότητα του σχεδιασμού διερευνήθηκε σε υδραυλικό ομοίωμα κλίμακας 1:12,5 που βασίσθηκε σε συνθήκες δυναμικής ομοιότητας κατά Froude για χαρακτηριστικές τιμές παροχής. Η επεξεργασία των μετρήσεων έδειξε ότι με κατάλληλη διάταξη πλευρικών στοιχείων τραχύτητας και διαμόρφωση της λεκάνης καταστροφής ενέργειας ελέγχεται η τιμή της ταχύτητας, ικανοποιείται η απαίτηση μεγίστου βάθους ροής σε σχέση με τις διαστάσεις της σήραγγας και επιτυγχάνεται επαναληψιμότητα της ροής σε κάθε module.The free-surface flow in a tunnel of steep bed slope 1:10 is studied experimentally. The effectiveness of vertical roughness elements on the side walls and energy dissipation basins with blocks is investigated, with the aim to reduce flow velocity in the tunnel. The design is based on the concept of repeated modules in order to achieve flow repeatability. The scale of the physical model was 1:12.5 under Froude similarity conditions. The analysis of measurements indicates that a suitable arrangement of vertical roughness elements on the side walls and a suitable design of the energy dissipation basin can control the flow velocity magnitude, satisfy the maximum flow depth requirement with respect to the tunnel dimensions, and achieve flow repeatability in each modul

Most Readmissions Following Ankle Open Reduction Internal Fixation are Unrelated to Surgical Site Issues

Category: Trauma Introduction/Purpose: Ankle fractures are commonly-sustained injuries, and frequently require open reduction internal fixation (ORIF). It is generally a safe and effective surgical procedure, however, as quality-based reimbursement models become increasingly affected by readmissions within thirty days, it is important to determine causes and risk factors for patients to be readmitted after discharge. Methods: Patients that underwent ORIF for ankle fractures were identified from the prospectively-collected American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2013 to 2014. Baseline demographics, comorbidities, and fracture characteristics (open vs. closed, location of fracture such as lateral malleolus, medial malleolus, bimalleolar, or trimalleolar) were determined. Modified Charlson Comorbidity Index (CCI) was used as a measure of overall comorbidity burden. Rates of thirty-day adverse events and readmissions were determined, as well as the causes for readmission. Multivariable logistic regression analyses were performed to identify risk factors significantly associated with having any adverse events and being readmitted within thirty days of surgery. Results: 5,056 ankle ORIF patients were included. 167 (3.3%) were open fractures. The rate of any postoperative adverse event was 5.2%. There were 127 readmissions, with 116 (91.3%) being unplanned readmissions. Of the 116 unplanned readmissions, 49 (42.2%) were for reasons related to the surgery or surgical site, with the most common causes being deep surgical site/hardware infection (12.9%), superficial site infection (11.2%), and wound disruption (6.9%). Most readmissions were for reasons unrelated to the surgical site (51.7%), including cardiac disorders (8.6%), pulmonary disorders (7.8%), and neurologic/psychiatric disorders (6.9%). With multivariable logistic regression, the strongest risk factors for readmission were history of pulmonary disease (Odds Ratio [OR] 2.29), ASA ≥ 3 (OR 2.28), and open fracture (OR 2.04, all p < 0.05). (Figure 1) Conclusion: Postoperative readmissions following ankle fracture ORIF are important to consider in this era of quality-based hospital reimbursement models. In this cohort of 5,056 ankle ORIF cases, 2.5% of patients were readmitted within thirty days, with 51.7% of all unplanned readmissions due to causes unrelated to the surgery or surgical site. This suggests that close medical follow-up with non-orthopaedic providers may be necessary after discharge. To assist clinicians in preoperative risk stratification, predictors of readmission were history of pulmonary disease, increased ASA class, and open fracture. Higher bundled reimbursements may be justified for cases with these risk factors

Most Readmissions Following Ankle Fracture Surgery Are Unrelated to Surgical Site Issues

Background: Ankle fracture surgeries are generally safe and effective procedures; however, as quality-based reimbursement models are increasingly affected by postoperative readmission, we aimed to determine the causes and risk factors for readmission following ankle fracture surgery. Methods: Ankle fracture cases were identified from the prospectively collected American College of Surgeons National Surgical Quality Improvement Program from 2013 to 2014. Demographics, comorbidities, and fracture characteristics were collected. Rates of 30-day adverse events and readmissions were determined as well as the causes for readmission. Multivariable logistic regression analyses were performed to identify risk factors associated with having any adverse events and being readmitted within 30 days of surgery. Results: There were 5056 patients included; 167 (3.3%) were open fractures. The rate of any postoperative adverse event was 5.2%. There were 116 unplanned readmissions, with a readmission rate of 2.3%. Of the 116 unplanned readmissions, 49 (42.2%) were for reasons related to the surgery or surgical site, with the most common causes being deep surgical site/hardware infections (12.9%), superficial site infections (11.2%), and wound disruption (6.9%). Most readmissions were for reasons unrelated to the surgical site (51.7%), including cardiac disorders (8.6%), pulmonary disorders (7.8%), and neurological/psychiatric disorders (6.9%). The cause of readmission was unknown for 6% of readmissions. With multivariable logistic regression, the strongest risk factors for readmission were a history of pulmonary disease (odds ratio [OR], 2.29), American Society of Anesthesiologists (ASA) class ≥3 (OR, 2.28), and open fractures (OR, 2.04) (all P < .05). Conclusion: In this cohort of 5056 ankle fracture cases, 2.3% of patients were readmitted within 30 days, with at least 51.7% of all unplanned readmissions due to causes unrelated to the surgery or surgical site. Predictors of readmission included a history of pulmonary disease, higher ASA class, and open fractures. Based on these findings, we advocate close medical follow-up with nonorthopaedic providers after discharge for high-risk patients. Level of Evidence: Level III

Republication of “Most Readmissions Following Ankle Fracture Surgery Are Unrelated to Surgical Site Issues: An Analysis of 5056 Cases”

Background: Ankle fracture surgeries are generally safe and effective procedures; however, as quality-based reimbursement models are increasingly affected by postoperative readmission, we aimed to determine the causes and risk factors for readmission following ankle fracture surgery. Methods: Ankle fracture cases were identified from the prospectively collected American College of Surgeons National Surgical Quality Improvement Program from 2013 to 2014. Demographics, comorbidities, and fracture characteristics were collected. Rates of 30-day adverse events and readmissions were determined as well as the causes for readmission. Multivariable logistic regression analyses were performed to identify risk factors associated with having any adverse events and being readmitted within 30 days of surgery. Results: There were 5056 patients included; 167 (3.3%) were open fractures. The rate of any postoperative adverse event was 5.2%. There were 116 unplanned readmissions, with a readmission rate of 2.3%. Of the 116 unplanned readmissions, 49 (42.2%) were for reasons related to the surgery or surgical site, with the most common causes being deep surgical site/hardware infections (12.9%), superficial site infections (11.2%), and wound disruption (6.9%). Most readmissions were for reasons unrelated to the surgical site (51.7%), including cardiac disorders (8.6%), pulmonary disorders (7.8%), and neurological/psychiatric disorders (6.9%). The cause of readmission was unknown for 6% of readmissions. With multivariable logistic regression, the strongest risk factors for readmission were a history of pulmonary disease (odds ratio [OR], 2.29), American Society of Anesthesiologists (ASA) class ≥3 (OR, 2.28), and open fractures (OR, 2.04) (all P < .05). Conclusion: In this cohort of 5056 ankle fracture cases, 2.3% of patients were readmitted within 30 days, with at least 51.7% of all unplanned readmissions due to causes unrelated to the surgery or surgical site. Predictors of readmission included a history of pulmonary disease, higher ASA class, and open fractures. Based on these findings, we advocate close medical follow-up with nonorthopaedic providers after discharge for high-risk patients. Level of Evidence: Level III