Topographical measurement of the attachments of the central band of the interosseous membrane on interosseous crests of the radius and ulna

Background: To suggest a reasonable isometric point based on the anatomical consistency of interosseous membrane (IOM) attachment in association with topographic characteristics of the interosseous crest, the footprints of the central band (CB) of the IOM on the radial and ulnar interosseous crests (RIC and UIC) were measured.Methods: We measured the distance from the CB footprints from each apex of both interosseous crests in 14 cadavers and the angles between the forearm axis of rotation (AOR) and the distal slopes of the RIC and UIC in 33 volunteers. Results: The CB footprints lay on the downslope of both interosseous crests with its upper margin on average 3-mm proximal from the RIC's apex consistently in the radial length, showing normality (p>0.05), and on average 16-mm distal from the UIC's apex on the ulna without satisfying normality (p<0.05). The average angle between the UIC's distal slope and the AOR was 1.3°, and the RIC's distal slope to the AOR was 14.0°, satisfying the normality tests (p>0.05), and there was no side-to-side difference in both forearms (p<0.05).Conclusions: The CB attached to the downslope just distal to the RIC's apex constrains the radius to the UIC that coincides with the AOR of the forearm circumduction, maintaining itself both isometrically and isotonically.

GROWTH OF THE PEDIATRIC KNEE MENISCUS: A CADAVERIC STUDY

Background: The menisci of the knee play a critical role in maintaining structural integrity, as well as in load bearing and shock absorption. In adolescent patients, meniscal tear is a very common sports injury, and is frequently associated with concomitant traumatic injuries including tibial eminence fracture or ACL tear. The incidence of pediatric meniscal tears is increasing, and anatomic studies to guide repair, saucerization and transplantation do not exist. Hypothesis/Purpose: This study’s purpose was to evaluate meniscus dimensions in the developing meniscus and provide anatomic parameters for repair, saucerization, resection, transplantation. Methods: From images of 29 dissected cadaveric knee specimens between 1 month and 132 months of age obtained on a copy stand (14 left knee, 15 right knee), we made direct length measurements from the inner to outer meniscus rim at 45 degree intervals (12, 1:30/10:30, 3:00/9:00, 4:30/7:30 o’clock, 6 o’clock) using Autodesk Fusion 360 software (Figure 1.1). We also measured width between the outer medial and lateral meniscus rims, as well as CT measurements of coronal and sagittal width of the tibial plateau using OsiriX DICOM software. Generalized linear models were used to evaluate the associations of meniscal length measurements with age, tibial width, and meniscal width measurements. All statistical analyses were completed with a two-sided level of significance of 0.05. Results: All radial length measurements were predicted to increase significantly with age (p < 0.01), as coronal tibial width increases (p < 0.05), and as lateral-medial meniscal width increases (p < 0.001) (Figure 1.2). Other than the lateral 3 o’clock measurement (p = 0.119), all radial measurements were predicted to increase significantly as sagittal tibial width increases (p < 0.05). The posterior zones of the medial meniscus (6:00, 4:30/7:30) were found to increase in radial length at a faster rate than the anterior zones. The anterior zones of the medial meniscus (12:00, 1:30/10:30) had the slowest rate of growth. Discussion/Conclusion: Meniscus radial length is related to age, tibial plateau width, and lateral-medial meniscus width. Radial dimensions from normal lateral menisci may allow the surgeon to obtain ideal size of resection, saucerization of discoid menisci. The growth of medial meniscus posterior zones is greater than the anterior zones. This may be attributed to increased posterior region load bearing which increases with ambulation in the developing child. Improved anatomic understanding may help surgeons plan for discoid resection/saucerization/repair, and also support appropriate selection of meniscus allograft for transplantation. [Figure: see text][Figure: see text]

The Usefulness of Radial Column Plate in Distal Radius Fracture: Indications and Results

Purpose: The most common surgical treatment for distal radius fracture is internal fixation using volar locking plates, but it is sometimes difficult to maintain reduction with them. Therefore, this research reports the results of surgical treatment with additional radial column plates.Methods: We analyzed 12-month follow-up results in 100 cases. The patients had the B or C types of distal radius fractures, in accordance with AO classification, and underwent surgical treatment at our hospital from May 2013 to December 2019. There were 16 cases of B-type and 84 cases of C-type fractures. Out of these, 87 were treated with volar locking plates (V group) and 13 had additional radial column plates (VR group). The results of surgical treatment were examined clinically by measuring the disabilities of the arm, shoulder and hand (DASH) and Mayo wrist score, and radiologically by measuring the radial length, radial inclination, and volar tilt, before and after surgery.Results: After treatment, the radiographic average in the V group showed a radial length of 12.3 mm, radial inclination of 20.2°, and volar tilt of 5.8°, while the VR group showed 11.6 mm, 22.3°, and 9.0° respectively. A statistically significant difference was found in the DASH score, and the DASH score showed good results in the VR group.Conclusion: Additional radial column plate fixation is worth considering because it provides clinically and radiologically satisfactory results in treatment of B and C types distal radius fracture involving articular surface.

Design and numerical simulation of a microwave antenna with coaxial slots for preventing secondary formation of gas hydrate

Gas hydrate is a new clean energy resource with polar molecule. However due to the change of temperature and pressure during extraction process, there will be secondary formation of gas hydrate, which usually occurs in reservoirs or pipelines near the wellhead. It is significance to prevent secondary formation of hydrate because of safety issues or production rate reduction caused by it. Theoretically, microwave heating can accelerate the decomposition of gas hydrate. Therefore, it is possible to use microwave radiation to prevent secondary formation of hydrate. In this paper, a microwave antenna with special shaped coaxial-slots was designed. Based on electromagnetics and antenna transmission theories, the key parameters of the coaxial-slot antenna were calculated. The frequency is 2.45 GHz, the impedance is 50 ohms, and ratio of outer to inner conductor radius is 3.32. The slots were designed as ‘H’-shape with the width is 2 mm, the radial length is 12mm, the axial length is 14 mm and the interval is 35 mm. Teflon was used as filling material and the radome. Then the software HFSS and ANSYS were used to analyze the electromagnetic field and temperature field to further optimize the parameters. It will be proved that the microwave antenna can heat gas hydrate and prevent the secondary formation.

Distal Radius Measurements in Indian Population-An comprehensive Morphometrical Analysis

The four basic morphometrical parameters regarding the anatomy of the distal end of radius bone are radial inclination, palmar tilt/volar tilt, radial height (length) and ulnar variance. The management of various conditions such as fracture of the distal radius bone, designing of the distal radius plates and kinesiology utilize the parameters in the morphometrical measurement of the distal end radius. The goal of our study is to bring about the normalized values of the morphometrical parameters of the DER among the general Indian population for helping in designing the distal radius plates. The study was conducted in a tertiary care hospital in India. It was a single hospital based study. The views considered for the study were the true posteroanterior (PA) and the lateral view (with neutral rotation). The posteroanterior view was used for the measurement of radial inclination, radial length (height) and the ulnar variance. The lateral view helped in the accomplishment of the measurement of the palmar/volar tilt. The statistical analysis was done by Microsoft Excel 2007 (Data add in function was installed for the analysis of the collected data). The means of the morphometrical parameters was compared with the help of T-test. Two hundred (n=200) radiographs were included for analysis under this study. The mean value of radial inclination was 20.7 8 ° ± (SD) 3.45° [Range: 14.9-29.1°], palmar/volar tilt 10.99° ± (SD) 3.87° [Range: 1.8-18.6°], radial length/height 11.39 mm ± (SD) 1.97 mm [Range: 8.3-27.7 mm], and ulnar variance 0.90 mm ± (SD) 3.14 mm [Range: +0.70 to +3.70]. This study will lead for further researches in the analysis of the morphometrical parameters of the distal end of radius bone in the Indian population. For the clinical management of the injuries around the wrist joint the results of this study can be used as a reference standard to anatomically align the bones and the affected structures.

Film Thickness and Friction Investigations in a Fluid Film Thrust Bearing Employing A New Conceived Micro-Texture on Pads

This paper presents the performance behaviors (coefficient of friction, minimum film thickness, and pressure distributions) of a fluid film thrust bearing using a newly conceived micro-texture on pads. In the numerical investigation, the Reynolds equation has been discretized using the finite element formulation followed by the solution of algebraic equations employing the Fischer-Burmeister-Newton-Schur (FBNS) algorithm, which satisfies the mass-conservation phenomenon arising due to the commencement of cavitation in the lubricating film. The effects of parameters (micro-texture/pocket depth, circumferential/radial length of micro-texture and pocket, etc.) of new texture on the performance behaviors of the thrust bearing have been explored and presented herein for the range of input data. It has been found that the minimum film thickness has increased up to 48%, and the friction coefficient reduced up to 24% in comparison to conventional plain pad case.

Surgical treatment of fractures of the distal radius – ORIF vs external fixation with ligamentotaxis

Introduction: The study compares the results of open reduction using volar locking plates with ligamentotaxis by external fixation in fractures of distal radius type 2R3C according to AO classification. Methods: A retrospective study evaluating the results of osteosynthesis in patients with distal radius fractures type 2R3C according to AO classification, operated until December 2018. The ORIF method with volar locking plates (LCP) was used in 54 patients, and closed reduction with ligamentotaxis using external fixation (EF) was used in 33 patients. The mean age of the patients was 46.7 years in the LCP group and 59.6 years in the EF group. All were evaluated for their X-ray and functional outcomes and according to the Green and O’Brien score at 6 and 12 months after surgery. Results: According to X-rays at 12 months in the LCP group, the mean sagittal tilt was 10.13°, the mean radial inclination was 23.89°, and the mean radial length was 11.84 mm. In the EF group, the mean sagittal tilt was 6.32°, the mean radial inclination was 24.78°, and the mean radial length was 9.89 mm. According to the Green and O’Brien score, we recorded a mean score of 84.44 points in the LCP group at 12 month; we achieved good and excellent results in 83.33% of the patients and no poor result was observed. In the EF group the final mean score was 77.27; good and excellent results were achieved in 45.46% of the patients and a poor result in one patient. Conclusion: Based on the results in our group of patients, the internal type osteosynthesis using LCP implants can be recommended as a first-choice technique in the treatment of 2R3C fractures according to AO classification.

Functional and radiological outcome of Colles fracture treated conservatively with plaster and cast

Background and Objectives: Fractures of distal radius are commonly encountered in orthopedic emergency. Various treatment methods are available including closed reduction and immobilization in cast, percutaneous pinning, pins and plaster, external fixation, open reduction and internal fixation with or without bone graft or substitute. There are no clear guidelines to follow. The aim of this study is to compare the radiological and functional outcome of distal radius fracture treated conservatively with cast alone. Material and Methods: Sixty patients suffering from extra articular distal radius fracture were recruited for study. They were all treated conservatively with cast alone. They were followed up for 6 months. The radiological outcome in terms of dorsal angulation, radial length, radial angulation and ulnar variance and functional outcome in terms of Mayo wrist score was assessed. Results: At 6 months follow up dorsal angulation, radial length, radial angulation and ulnar variance were - 5±3.20 degrees, 7.80±0.77mm, 20.47±2.29 degrees and 1.27±0.77 respectively. Functionally 20 patients had good outcome, 32 patients had satisfactory outcome and 8 patients had poor outcome in terms of Mayo wrist scores. Conclusion: Conservative management with cast is an effective treatment modality for Frykmans type I and II Colles fracture with satisfactory functional and radiological outcome.

Selecting the Dimensions of the Vaneless Diffuser of a Centrifugal Compressor Stage at the Primary Design Phase

The advances in the primary design method of centrifugal compressors of the Universal Modeling Method have led to the need to analyze and revise the recommendations for the optimal size and configuration selection of vaneless diffusers of centrifugal compressor stages. The results of CFD calculations of a family of vaneless diffusers with different relative width, radial length, velocity coefficients and flow angles at the inlet are used to develop new recommendations. The choice of the optimal width of the vaneless diffuser is based on ensuring a non-separable flow in it at the boundary of the surge. The optimal value of the relative radial length of the diffuser is in the range of 1.65–2.0. Considering the above, a formula for selecting the vaneless diffuser outer diameter is proposed depending on the design flow rate coefficient. The developed primary design method of vaneless diffusers is included in the software programs of the Universal Modeling Method and is used in design and research practice.