Detailed observation of axis ring fractures using computed tomography: a retrospective analysis of 202 cases

Background: There is a dearth of research observing the precise anatomical location, pattern, and frequency of the fracture lines in axis ring fractures based on large size sample database and deducing the possible injury mechanism for such fractures. The study aimed to observe the anatomical features of axis ring fractures and evaluate the probable mechanism of injury.Methods: 202 patients with axis ring fractures were identified. According to the involvement of anatomical structures, the axis ring injuries were classified into facet joint injury and pure bony injury. The axis ring was also divided into: anterior, middle, and posterior elements. The anatomical structures involvement and fracture patterns of such fractures were observed using CT. Result: 501 anatomical structures of the axis ring were involved in 202 patients, including 288 facet joints injuries and 213 bony injuries. For facet joints injuries, the most common injuries were superior articular facet injuries, and for pure bony injuries, the most common injuries were pediculoisthmic component fractures. In regard to different element of the axis ring, the injuries of anterior element were more common than that of middle or posterior element. Most of (76.2%) axis ring fractures were asymmetrical, with different elements of the axis ring damaged on different side. Conclusion: In axis ring fractures, fracture lines could occur in any part of the ring. Facet joints injuries were more common than pure bony injuries, and the injuries of anterior element were more common than that of middle or posterior element. The probable mechanism of such injuries might be hyperextension and axial load, with an additional rotational load.

South Africa’s Eskom will weigh on economic rebound

Significance Capacity constraints across Eskom’s power stations have resulted in sustained rotational load shedding (power outages) in recent weeks, while its debt and liquidity issues risk undermining already subdued growth prospects. Impacts The national energy regulator is unlikely to accede to the full amount of Eskom’s application for a 15% price increase over three years. Eskom’s turnaround will prove crucial to sustaining any broader national economic recovery and improvement in investor sentiment. Major job cuts at Eskom will likely be avoided until after the forthcoming general election expected in May.

PENGARUH VARIASI MAIN JET NOZZEL PADA SISTEM KARBURATOR TERHADAP UNJUK KERJA MESIN (Studi Kasus Beberapa Tingkat Oktan)

This study discusses the effect of variations in the diameter of the main jet nozzle and three types of fuel with an octane rating of 88, 90 and 92 on the performance of the motor fuel. Performance analysis covering torque, power and specific fuel consumption (SFC). In order to determine the maximum performance that can be generated on any variation of the diameter of the main jet nozzles, and types of fuel. At the time of this experiment performed with a 4 stroke engine Honda GX-160, using hydro tool dynamometer and uses premium fuel. The data taken is the engine rotation, the force measured on the dynamometer and the time spent fuels. Tests conducted at the Laboratory of Energy Conversion Mechanical Engineering UNTAR Jakarta. Testing is done by means of rotational load mengvariasikan to gain strength in each round machine with a variety of major diameter nozzle jet fuel and octane. Variation of the engine rotation starts at minimal rotation until maximum.

Shoulder Muscle Activation Levels During Exercises With Axial and Rotational Load on Stable and Unstable Surfaces

This study evaluated the effects of instability on the EMG activity of scapular stabilizing and upper limb muscles during exercises with axial and rotational load. Twenty male volunteers (20.9 ± 1.8 years, 174.1 ± 0.04 cm, 73.17 ± 8.77 kg) experienced in strength training participated in a crossover design. Muscle activation of anterior deltoid (AD), posterior deltoid (PD), pectoralis major (PM), biceps brachii (BB), triceps brachii (TB), upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) were determined on both conditions. Participants performed a single series of 10 repetitions of bench press and fly exercises on stable (bench) and unstable (proprioceptive disc) conditions at 60% of 1-RM. The Friedman test and post hoc Dunn’s indicated that the unstable condition showed greater EMG activity for AD (P = .001) and BB (P = .002) on the fly exercise, SA (P = .001) and LT (P = .048) on the bench press, and PM (P ≤ .002) on both exercises. These results show that using an unstable surface in exercises with rotational load provides superior EMG activity of the agonist muscles, while in exercise with axial load, the instability favors EMG activity of the scapular stabilizing muscles.

Cementing a Polyethylene Cup into a Well Fixed Acetabular Metal-on-Metal Resurfacing Component? An Experimental Investigation

Introduction Adverse reactions to metal debris often indicate revision surgery in metal-on-metal (MoM) hip arthroplasty and an exchange of the MoM bearing into either a metal on polyethylene or a ceramic-on-polyethylene articulation. At the moment the removal of the entire implant system is the most reasonable method. In order to avoid bone loss caused by the removal of a well-fixed acetabular component, the purpose of this study was to measure the stability of a cemented polyethylene (PE) cup in an acetabular hip resurfacing component and to examine if such a method could be suitable for clinical use. Methods PE cups were cemented into 2 different hip resurfacing components and biomechanical tests were applied to measure failure torques under lever out and rotational load. Results In all cases failure of the interface between the resurfacing components and the cement layer occurred at a very low load (0.14 Nm-61.50 Nm). Discussion The early failure occurred due to lacking interdigitation of cement and the polished metal surface. Thus we warn against cementing a PE cup into acetabular hip resurfacing components for clinical use.