Pressure Assisted Bonding Process of Stainless Steel on Titanium Alloy Using Powder Metallurgy

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Titanium alloys have been widely used in many industrial applications. Nevertheless, efforts to improve their properties are continually increasing. One of the most effective routes to improve strength, hardness and wear resistance is to create a coating layer on the substrates. In the current study, stainless steel was selected for the in-situ joining and creating a continuous layer on the Ti6Al4V alloy. The Joining process was carried out at two different temperatures, 950 oC and 1050 oC, and the mechanical properties of the bonded materials were investigated employing hardness, bending strength and wear tests, while the bonding interface layer between the alloys powders was characterized by optical and scanning electron microscopes. The results showed that the higher the joining temperature, the wider the interfacial zone between the coating layer and substrate. The hardness and wear properties of the joint materials increased at 1050oC, while the bending stress was reduced and debonding was observed after the bending test. The chemical composition at the interface zone was identified by energy dispersive X-ray analysis, and the results showed high diffusion rates between the elements. As a result, the process used in the current study can be used for many titanium alloys, and their use in industrial applications can be increased

Effects of early manual therapy on functional outcomes after volar plating of distal radius fractures: A randomized controlled trial

We sought to investigate the effects of early manual therapy on functional outcomes in patients treated with volar plating of a distal radius fracture (DRF). This was a prospective, single-blinded, randomized controlled trial. Patients treated with volar plating of a DRF were randomly assigned to either Early Manual Therapy Group (EMTG, n = 19) or Standard Physiotherapy Group (SPG, n = 20). While SPG received standard physiotherapy, EMTG received standard physiotherapy plus Mulligan's Mobilization with Movement technique two sessions a week, through 12 weeks. Function, pain intensity, range of motion, grip strength and the level of disability were assessed using the Patient Rated Wrist Evaluation (PRWE), Visual Analog Scale (VAS), goniometer, hand dynamometer and Disabilities of Arm, Shoulder and Hand (DASH) Questionnaire, respectively. Measurements were made at 3, 6, and 12 weeks postoperatively. Of the 54-screened patients, 39 met the inclusion criteria and were randomized. In total, 32 patients (EMTG, n = 15; SPG, n = 17) were analyzed. EMTG had significantly better DASH score and wrist flexion at 12 weeks, less pain and better PRWE total score, wrist extension, ulnar/radial deviation, supination and grip strength at all time points. Moreover, wrist flexion increased more with the addition of early manual therapy than standard physiotherapy alone (26.50 +/- 13.19 versus 16.21 +/- 16.06). The addition of early manual therapy to standard physiotherapy may contribute to better functional outcomes and be more effective in increasing wrist flexion in patients treated with volar plating of a DRF. (C) 2020 SFCM. Published by Elsevier Masson SAS. All rights reserved

Evaluation of Corneal Topography and Biomechanical Parameters after Use of Systemic Isotretinoin in Acne Vulgaris

Purpose. We report the effect of isotretinoin on corneal topography, corneal thickness, and biomechanical parameters in patients with acne vulgaris. Method. Fifty-four eyes of 54 patients who received oral isotretinoin for treatment of acne vulgaris were evaluated. All patients underwent a corneal topographical evaluation with a Scheimpflug camera combined with Placido-disk (Sirius), ultrasonic pachymetry measurements, and corneal biomechanical evaluation with an ocular response analyzer at baseline, in the 1st, 3rd, and 6th months of treatment, and 6 months after isotretinoin discontinuation. Results. The thinnest corneal thickness measured with Sirius differed significantly in the 1st, 3rd, and 6th months compared with the baseline measurement; there was no significant change in ultrasonic central corneal thickness measurements and biomechanical parameters (corneal hysteresis and corneal resistance factor) throughout the study. Average simulated keratometry and surface asymmetry index increased significantly only in the first month of treatment according to the baseline. All changes disappeared 6 months after the end of treatment. Conclusion. Basal tear secretion and corneal morphologic properties were significantly influenced during the systemic isotretinoin treatment and the changes were reversible after discontinuation. No statistical important biomechanical differences were found to be induced by isotretinoin

Evaluation of Corneal Topography and Biomechanical Parameters after Use of Systemic Isotretinoin in Acne Vulgaris

Purpose. We report the effect of isotretinoin on corneal topography, corneal thickness, and biomechanical parameters in patients with acne vulgaris. Method. Fifty-four eyes of 54 patients who received oral isotretinoin for treatment of acne vulgaris were evaluated. All patients underwent a corneal topographical evaluation with a Scheimpflug camera combined with Placido-disk (Sirius), ultrasonic pachymetry measurements, and corneal biomechanical evaluation with an ocular response analyzer at baseline, in the 1st, 3rd, and 6th months of treatment, and 6 months after isotretinoin discontinuation. Results. The thinnest corneal thickness measured with Sirius differed significantly in the 1st, 3rd, and 6th months compared with the baseline measurement; there was no significant change in ultrasonic central corneal thickness measurements and biomechanical parameters (corneal hysteresis and corneal resistance factor) throughout the study. Average simulated keratometry and surface asymmetry index increased significantly only in the first month of treatment according to the baseline. All changes disappeared 6 months after the end of treatment. Conclusion. Basal tear secretion and corneal morphologic properties were significantly influenced during the systemic isotretinoin treatment and the changes were reversible after discontinuation. No statistical important biomechanical differences were found to be induced by isotretinoin

Iatrogenic lateral meniscus anterior horn injury in different tibial tunnel placement techniques in ACL reconstruction surgery – A cadaveric study

Objectives: The aim of this study was to analyze the effect of tibial tunnel positioning in single bundle and double bundle ACL reconstructions on lateral meniscus anterior root. Materials: Twelve single knee cadavers were used, 6 for a single bundle ACL reconstruction, which were reamed gradually starting from 8 mm, 9 mm and ended with a 10 mm reamers, while the other 6 were prepared for a double bundle ACL reconstruction in which 7 mm reamer for the AM tunnel and 6 mm reamer for the PL tunnel were used. After drilling, changes of lengths and thicknesses of anterior horns of the lateral menisci were recorded. Results: Before drilling, the groups were homogenous for the lateral menisci dimensions. After drilling, no statistically significant difference was noticed between the two groups. However, in single bundle group, 2 anterior horns width injury (1.44 mm and 2.13 mm) with the 9 mm reamer and 3 anterior horns width injury (2.51 mm, 3.55 mm and 4.28 mm) with the 10 mm reamer were recorded. However in double bundle group a single anterior horn width injury (2.82 mm) was recorded. Conclusion: Using a greater size reamer in single bundle reconstruction, causes a relatively higher risk of lateral meniscal anterior root injury. Lateral meniscus stability should be examined arthroscopically after reaming with large reamers. Keywords: Anterior cruciate ligament reconstruction, Anterior meniscus root, Meniscus injury, Tunnel reaming, Cadaver stud

Dual plating for fixation of humeral shaft fractures: A mechanical comparison of various combinations of plate lengths

Objective: The role of plate configuration was found inconclusive on the biomechanical effects of the plate size and hole number for dual plate constructions in humeral shaft fractures. The purpose of this study was to test the biomechanical stability of various dual plate constructions. Methods: Twenty-four left humeri (4th Generation Composite Humerus, Sawbones, Malmö, Sweden) with comminuted midshaft humeral fracture were used. Four groups of plate constructs were tested: laterally fixed 8-hole locking plate and screws were combined with anteriorly locking plates containing 0, 4, 6, or 8 holes in groups I, II, III, and IV, respectively. The alterations in axial, bending, and torsional angles were recorded. Results: There were no fixation failures during axial, bending, or torsional stiffness testing within the elastic behavior limits. Axial stiffness was highest in Group IV. Torsional stiffness, posterior-to-anterior bending stiffness, lateral-to-medial bending stiffness, and medial-to-lateral bending stiffness were lowest in Group I. Conclusion: The similar stiffness values for the 8-to-4 hole and 8-to-6 hole plate constructions indicate that the 8-to-4 hole construction is an option in young adults, while the stiffest 8-to-8 hole combination may be an option for osteoporotic patients. Keywords: Humeral shaft fractures, Dual plate, Fixatio