Semi-Rigid Fixation Using a Sliding Plate for Treating Fractures of the Mandibular Condylar Process

Occlusal displacement often occurs after surgery for condylar process fractures because it is difficult to reduce these fractures precisely. However, performing semi-rigid fixation using a sliding plate may overcome this limitation. A retrospective clinical comparison between semi-rigid and rigid fixations was performed. Among 34 patients who had unilateral condylar process fractures, 17 were treated with rigid fixation and the remaining with semi-rigid fixation using a sliding plate. For all patients, panoramic radiographs were collected 1 day and 6 months after surgery. In these radiographs, ramus height and condylar process inclination were measured, and the differences between the fractured and normal sides were assessed. Additionally, the radiographic density of the fracture area was measured. Differences in surgical outcomes and operative times between the two groups and changes in postoperative deviations within each group were analyzed. There was no statistically significant difference in ramus height and condylar process inclination between the two groups at postoperative day 1 and 6 months. Radio-density was observed to be higher in the rigid fixation group, and it increased with time in both groups. The semi-rigid fixation group had a significantly shorter operative time than the other group did. Semi-rigid and rigid fixations showed no differences in terms of effectiveness and outcomes of surgery. In terms of operative time, semi-rigid fixation was superior to rigid fixation.

Optimal surgical methods to treat intertrochanteric fracture: a Bayesian network meta-analysis based on 36 randomized controlled trials

Background There are several surgical methods to treat intertrochanteric fracture: dynamic hip screw (DHS), compression hip screw (CHS), percutaneous compression plate (PCCP), Medoff sliding plate, less invasive stabilization system (LISS), Gamma nail, proximal femoral nail (PFN), and proximal femoral nail anti-rotating (PFNA). We therefore conducted a network meta-analysis to compare eight surgical interventions, including DHS, CHS, PCCP, Medoff sliding plate, LISS, Gamma nail, PFN, and PFNA, to provide the optimal surgical intervention for intertrochanteric fracture. Methods An electronic search of 4 databases (PubMed, Embase, Cochrane library, and Web of Science) from inception to July 2020. Two or more of the eight surgical interventions, including the DHS, CHS, PCCP, Medoff sliding plate, LISS, Gamma nail, PFN, and PFNA, for intertrochanteric fracture were included. The methodological quality of the included studies was assessed using the Cochrane Collaboration risk of bias (ROB) tool. Network meta-analysis was conducted by using R-3.5.1 software with the help of package “gemtc”. The odd ratios (ORs) with 95% credibility interval (CrI) were used to assess complications and standard mean difference (SMD) with 95% CrI to calculate the continuous outcomes (operative time, intraoperative blood loss, and Harris hip score). Surfaces under the cumulative ranking curves (SUCRA) were used to rank the intervention. Results A total of 36 RCTs were included in this study. The results of this network meta-analysis showed that, compared with the CHS and DHS group, PFNA exhibited a beneficial role in reducing the blood loss (SMD, 152.50; 95% CrI, 72.93 to 232.45; and SMD, 184.40; 95% CrI, 132.99 to 235.90, respectively). PFNA achieved the lowest value for the surface under the cumulative ranking curve (SUCRA) for the blood loss (SURCA = 0.072) and highest of Harris hip score (SURCA = 0.912). PCCP may have the lowest probability of the operative time (SURCA = 0.095). There were no significant differences among the eight surgical procedures in complications. Conclusion PFNA technique is the optimal treatment method for intertrochanteric fracture. Larger, longitudinal RCTs addressing current limitations, including sources of bias, inconsistency, and imprecision, are needed to provide more robust and consistent evidence.

Menentukan Predictive Maintenance Pada Kerusakan Turbocharger Diesel Engine

Diesel Engine yang beroperasi pada salah satu pembangkit listrik di wilayah Sulawesi mengalami kerusakan pada turbocharger, indikasi sebelum kejadian unit trip/shutdown dan terindikasi di sistem Module Bearing Display Module (BDM) turbin dan kompresor disisi bank kiri, Module vibrasi display (VDM) pada bank kiri, modul vibrasi display axial bank kiri. Untuk mengidentifikasi kerusakan, operator melakukan pengecekan turbocharger pada bank kiri yang mengalami kerusakan dan setelah dilakukan pembongkaran komponen turbocharger ditemukan turbin wheel patah. Tujuan dalam penelitian ini menentukan akar penyebab kerusakan turbocharger agar kerusakan yang sama tidak terulang kembali. Adapun metode dalam penelitian ini adalah uji laboratorium komponen turbocharger yang patah. Dari kerusakan turbocharger bank kiri probability disebabkan oleh: 1) partikel valve, 2. Partikel bellow. Hasil dan Pembahasan kerusakan turbin wheel disebabkan vibrasi pada engine, yang mengakibatkan kerusakan pada wheel turbocharger. Vibrasi yang berasal dari sistem pembakaran yang tidak normal, dan menyebabkan pengelasan antara sliding plate dengan metal base pada bellows terlepas dan terdorong gas buang menuju turbocharger. Saran pengecekan secara berkala secara mengukur parameter vibrasi pada unit pembangkit.

Experimental Validation of a Direct Fiber Model for Orientation Prediction

Predicting the fiber orientation of reinforced molded components is required to improve their performance and safety. Continuum-based models for fiber orientation are computationally very efficient; however, they lack in a linked theory between fiber attrition, fiber–matrix separation and fiber alignment. This work, therefore, employs a particle level simulation which was used to simulate the fiber orientation evolution within a sliding plate rheometer. In the model, each fiber is accounted for and represented as a chain of linked rigid segments. Fibers experience hydrodynamic forces, elastic forces, and interaction forces. To validate this fundamental modeling approach, injection and compression molded reinforced polypropylene samples were subjected to a simple shear flow using a sliding plate rheometer. Microcomputed tomography was used to measure the orientation tensor up to 60 shear strain units. The fully characterized microstructure at zero shear strain was used to reproduce the initial conditions in the particle level simulation. Fibers were placed in a periodic boundary cell, and an idealized simple shear flow field was applied. The model showed a faster orientation evolution at the start of the shearing process. However, agreement with the steady-state aligned orientation for compression molded samples was found.