For dorsal stabilization, rigid implant systems are be coming increasingly complemented by numerous dynamic systems based on pedicle screws. Numerous posterior non-fusion systems have been developed within the past decade to resolve the disadvantages of rigid instrumentations and preserve spinal motion. For dorsal stabilization, rigid implant systems are becoming increasingly complemented by numerous dynamic systems based on pedicle screws and varying direction. However, it is still unclear which direction is most suitable to accomplish a physiologically related dynamic stabilization, and which loadings conditions are induced to the implants. The aim of this study was to investigate the effect of a new telescopic dynamic stabilization device. Evaluation of the effects on the dynamic stabilization of the spine in terms of segmental range of motion (RoM), and implant loadings.Background
Purpose
Intramedullary nailing is a widely accepted treatment method for femoral fractures. Failure of locking screws is often a threatening complication, particularly on comminuted fractures. For comminuted fractures, the locking nails are load-bearing devices. The load transfer between fractured fragments is made through especially the locking screws for these load bearing situations. Nonunion, malunion, delayed union, shortening, and nail migration are the expected results if early failure of locking screws is present with comminuted fractures. In this study our aim was to compare the bending resistance of titanium and stainless steel locking screws. We tested 60 locking screws in six groups (titanium, stainless steel, unthreaded, low threaded and high threaded) in a steel tube that has 30 mm inner diameter, which imitates the lesser trochanter level. We determined the yield points at three-point bending tests that permanent deformation started in the locking screws using an axial compression testing machine.Background
Methods
Acetabular labral tears can cause pain and microinstability and are the most common indication for hip arthroscopy. Hip labral repair demonstrates better clinical outcome scores at a mean of 3.5 years post surgery than labral excision and tends to be performed in a younger age group. While different labral stitch configurations are possible, the most frequently used are a mattress stitch passed though the hip labrum at its widest part, or a simple loop surrounding the labrum. To determine the strength of variousrepair techniques and the impact suture passer sizesonhip labrum failure after cyclic loading. 35 unattached fresh-frozen bovine hip labrums were assigned to 5 repair techniques (7 specimens each): Group 1: horizontal mattress using a penetrating grasper; Group 2: vertical mattress using a penetrating grasper; Group 3: vertical mattress using asuture lasso; Group 4: Oblique repair using a penetrating grasper; Group 5: vertical mattress using a penetrating grasper and monopolar radio frequency device. Using a materials testing machine and after a 10N preload, each contruct was subjected to 20 cycles at 5N–80N. Cyclic elongation, peak-to-peak displacement, ultimate failure load, stiffness, and failure mode were recorded.Background
Methods
Femur fracture fixation systems depend on the stability of the supporting cortical screws, inside the host bone. Only a few works have studied the stability of cortical screws in femur shafts and compared their results with previous studies. In present study, five different cortical screw types are assessed using artificial femurs, under equated testing conditions. The maximum force needed to cause screw-bone inter face failure was measured, for each screw type by pullout tests. The obtained results were normalised according to traditional methods and cross-compared. The best performer was searched for and the effect of screw dimensions on the screw performance was investigated. To make the pullout tests solely dependent on screw dimensions, the effect of the bicortical bone thickness was eliminated by equating the conditions of screw insertion.Background
Methods
Currently about 4–6% of all femur fractures consist of distal femoral fractures. Different methods and implants have been used for the surgical treatment of distal femoral fractures, including intramedullary nails. Retrograde nail. By contrast with antegrade nails, surgical approach or retrograde nailing exposes the knee joint which may lead to tendency of infection and increased knee pain. Present study aims to compare the biomechanical behaviour of distal angular condyler femoral intramedullary nail (DACFIN), retrograde nail and plate fixation. Fifteen 4th generation Saw bones were used to evaluate the biomechanical differences between the groups (Group 1: Plate fixation, Group 2: Retrograde nailing, Group 3: DACFIN; (n=5)). Biomechanical test was performed by using an electromechanical test device Shimadzu (AG-IS 5kN, Japan). Displacement values were recorded by using a Non-contact Video Extensometer (DVE-101/201, Shimadzu, Japan) during the loading each femur with 5 cycles of 500 N at a rate of 10 N/s to determine axial stiffness. The faliure stiffness was measured by axial load to each constructat a displacement rate of 5 mm/min. Torsional loading applied to all groups in amount of 6 Nm of torque with a velocity of 18 degrees/min.Background
Methods
