The release of adhesions improves outcome following minimally invasive repair of Achilles tendon rupture

Purpose Operative repair of Achilles tendon rupture may lead to complications, which influence outcome adversely. The aim of this study was to determine the incidence, impact and response to treatment of post-operative adhesions. Methods From February 2009 to 2021, 248 patients operated on with percutaneous or minimally invasive surgical repair have been prospectively evaluated using the Achilles tendon Total Rupture Score (ATRS) and Heel-Rise Height Index (HRHI), following acute Achilles tendon rupture. Results Fourteen (5.6%) patients were identified as having adhesions. Four patients reported superficial adhesions and ten patients reported a deeper tightness of the tendon. At a mean (SD) of 10.5 (2.3) months following repair, the overall ATRS was at a median (IQR) 65 (44.5–78) points and (HRHI) was mean (SD) 81.5 (13.5)%. Of those deemed to have deep adhesions the antero-posterior diameter of the tendon was at mean (SD) 15.6 (4.6) mm. Open release of superficial adhesions resulted in improved ATRS in all patients. Endoscopic debridement anterior to the Achilles tendon led to alleviation of symptoms of tightness and discomfort from deep adhesions and improved outcome in terms of the ATRS score. At a mean (SD) of 15.9 (3.3)-month follow-up from initial rupture and repair, the patients reported at median (IQR) ATRS scores of 85 (64.8–92.8) points, Tegner level 5 (3–9) and mean (SD) HRHI 86.2 (9.5)%. Patients significantly improved both ATRS and HRHI following release at median (IQR) of 16.5 (− 1.8–29.3) points (p = 0.041) and mean (SD) 5.6 (8.3)% (p = 0.043). Conclusions The incidence of patient-reported adhesions following minimally invasive repair of Achilles tendon rupture was estimated to be 5.6%. The occurrence of superficial adhesions was associated with a lower outcome scores as well as symptoms of anterior tendon tightness and stiffness were associated with a lower score in most patients. Surgical release of adhesions led to a significant improvement in outcome.

A new deck arch bridge and a study on its mechanical properties by FE and experiment methods

In this study, a new type of deck arch bridge was proposed based on the triangle stability principle, and its mechanical properties were tested. The new deck arch bridge—named the superposed truss arch bridge—consists of main arches, auxiliary arches, a girder, and web members. These components adopt steel structures and are connected into a series of triangles to form a superposed truss structure. The new structural system design retains the advantages of the truss and arch structure. Additionally, the rise-span ratio of the main arch can be smaller in the new system design, so the rise height is smaller, which can decrease construction difficulty. The underlying mechanical principles of the new bridge were explained. A new type of railway deck arch bridge with a 650 m span was designed, and the finite element method was used to analyze its stiffness, strength, stability, and dynamic properties and the corresponding effects of the arch-axis coefficient, rise-span ratio, and span length on the mechanical properties. An experiment was carried out on a new deck arch bridge and a conventional deck arch bridge with the same span (10 m) to compare their performance. The results showed that the new deck arch bridge exhibited good mechanical properties while being inexpensive and easy to construct, which makes it suitable for high-speed railway bridges.

Effect of Proximity to Bed on 30° and 45° Inclined Dense Jets: A Numerical Study

Employing inclined dense jets is a common way for the disposal of brine effluent from coastal desalination plants. This paper numerically analyzes the mixing and geometrical properties of 30° and 45° inclined dense jets when they discharge close to the bed. For this purpose, two series of numerical simulations were developed. First, the nozzle acts as a free jet when it is placed far enough from the lower boundary. Meanwhile, in the second series, the distance between the nozzle tip and seabed is substantially reduced. Consequently, by comparing these two series, the effect of proximity to bed on the behavior of dense jets is investigated. The governing equations are solved by modifying a solver within the CFD package of OpenFOAM. The numerical results are presented in comparative figures and compared to the previous works. Comparisons indicated that the numerical model predicts the geometrical characteristics of dense jets in good agreement with the past experimental studies. However, the dilution predictions are conservative. It has been observed that proximity to the bed has almost no appreciable effects on the behavior of 45° jets. However, for 30° jets, when the bed proximity parameter ( Y0/LM ) falls below 0.14, normalized values of horizontal and vertical locations of centerline peak and return point dilution are slightly reduced while the terminal rise height remains untouched.

Age and Tightness of Repair Are Predictors of Heel-Rise Height After Achilles Tendon Rupture

Background: Achilles tendon rupture leads to weakness of ankle plantarflexion. Treatment of Achilles tendon rupture should aim to restore function while minimizing weakness and complications of management. Purpose: To determine the influence of factors (age, sex, body mass index [BMI], weight, time from injury to operative repair, and tightness of repair) in the initial surgical management of patients after an acute Achilles tendon rupture on 12-month functional outcome assessment after percutaneous and minimally invasive repair. Study Design: Cohort study; Level of evidence, 3. Methods: From May 2012 to January 2018, patients sustaining an Achilles tendon rupture receiving operative repair were prospectively evaluated. Tightness of repair was quantified using the intraoperative Achilles tendon resting angle (ATRA). Heel-rise height index (HRHI) was used as the primary 12-month outcome variable. Secondary outcome measures included Achilles tendon total rupture score (ATRS) and Tegner score. Stepwise multiple regression was used to create a model to predict 12-month HRHI. Results: A total of 122 patients met the inclusion criteria for data analysis (mean ± SD age, 44.1 ± 10.8 years; 78% male; mean ± SD BMI, 28.1 ± 4.3 kg/m2). The elapsed time to surgery was 6.5 ± 4.0 days. At 12-month follow-up, patients had an HRHI of 82% ± 16% and performed 82% ± 17% of repetitions compared with the noninjured side. Participants had a mean ATRS of 87 ± 15 and a median Tegner score of 5 (range, 1-9), with a reduction in Tegner score of 2 from preinjury levels. The relative ATRA at 12 months was –4.8° ± 3.9°. Multiple regression identified younger age (B = ±0.006; P < .001) and greater intraoperative ATRA (B = 0.005; P = .053) as predictors of more symmetrical 12-month HRHI ( R 2 = 0.19; P < .001; n = 120). Conclusion: Age was found to be the strongest predictor of outcome after Achilles tendon rupture. The most important modifiable risk factor was the tightness of repair. It is recommended that repair be performed as tight as possible to optimize heel-rise height 1 year after Achilles tendon rupture and possibly to reduce tendon elongation.

Jumping drops on the surface of the water

The paper proposes a theoretical model for the bouncing of a water drop on a free surface. The motion of a drop in air is described by the usual equations connecting the forces of inertia, gravity, and Stokes (viscosity resistance). The drop is considered spherical with a given surface tension. Numerical calculations were carried out using the same algorithm, but with different initial conditions. Some conditions are set for the droplet disintegration, others for the droplet reflection from the free surface. It is shown that the disintegration of a drop occurs periodically with a decrease in the drop size and an increase in the drop rise height. In the interval between droplet decays, periodic reflection from the free surface occurs with a decrease in the rise height.