BACKGROUND The neurocentral synchondrosis plays a role in the growth of the spine. The goal of this study was to determine whether asymmetric epiphysiodesis of this synchondrosis creates a scoliotic deformity in a growing-animal model and to correlate curve magnitude with the degree of closure of the synchondrosis. METHODS Two-month-old pigs were assigned to three groups. In the control group...

The physical status of an interference screw fixation in an anterior cruciate ligament (ACL) reconstructive surgery is a crucial factor of success. In this study, the insertion of the interference screw into a tibial bone tunnel, and the advancement of the screw between the tendon strands were investigated using both experimental and computer modeling. The mechanical behavior of the bone and so...

Abutment screw fracture, although uncommon, occurs in clinical practice (Fig. 1,A). In most circumstances, the fractured end can be retrieved and replaced by a new abutment screw. However, sometimes the screw cannot be removed conservatively. By using rotary instruments, internal threads of the screw hole may be damaged and the implant rendered useless. To overcome these problems, this article ...

In this paper, a modular designed automatic screw tightening shaft system, which is based on enhanced variable gain PID control, is proposed. Designed for the autonomous screw tightening operation, the screw tightening shaft enjoys huge potential for industry application. The screw tightening shaft and the screw tightening process are both mathematically modeled as an uncertain feedback system ...

The purpose of this study was to determine the influence of gender, screw design, and the approach on maximal screw length in scaphoid fracture fixation. Measurements were performed on 3D reconstructions of 20 CT scans of normal scaphoids. A comparison was made between 15 different available screw designs and between volar and dorsal screw placement. The length of the scaphoid along its central...

The studies on wollastonite reinforced recycled ABS (Acrylonitrile butadiene styrene) composites were investigated. Powder-based with a particle size of 13 microns was mixed Acrylonitrile styrene in various proportions wt.%. Recycled homogeneously and composite prepared using twin-screw extruder it pelletized. specimens the injection moulding process mechanical properties like tensile strength ...

To quantify the homogeneity of fiber dispersion in short fiber-reinforced polymer composites, a method for image texture analysis 3-dimensional X-ray micro computed tomography (µCT) images is presented this work. The adaption to specific requirements composite material accomplished using statistical region merging approach. Subsequently, applied evaluating specimens from an intermediate step lo...

STUDY DESIGN A prospective self-controlled study. OBJECTIVE The aim of the present study was to compare the application and clinical outcomes of transposterior arch lateral mass screw and lateral mass screw fixation of the atlas in the treatment of atlantoaxial instability. SUMMARY OF BACKGROUND DATA Atlas posterior screw fixation techniques comprise transposterior arch lateral mass screw f...

STUDY DESIGN A biomechanical spine model was used to evaluate the impact of screw design on screw-vertebra interface loading during simulated surgical corrections of adult scoliosis. OBJECTIVES To evaluate differences in screw-vertebra interface forces during adult scoliosis correction between favored angle (FA) screws with extension tabs and standard polyaxial screws while varying deformity ...

BACKGROUND It has been observed clinically that the Z-effect is a potential cause of failure of an intramedullary nail with two cephalic screws. It describes the migration behavior of the cephalic screws in the femoral head. The primary objective was to examine different cephalic screw configurations and test the load distribution between them as a function of their relative placement and their...