Recently it has been shown that anatomic tibial graft fixation in anterior cruciate ligament (ACL) reconstruction is preferable in order to increase isometry and knee stability. To facilitate anatomic patellar tendon graft fixation, customized graft length shortening is necessary. The purpose of this study was to compare the initial fixation strength of four different shortened patellar tendon ...

A previously well 30 year old man presented with a short history of intra-articular mechanical locking, swelling, and anteromedial joint line pain. There was localised tenderness, and McMurray's test was positive. Arthroscopy revealed a 3.6 x 2.6 x 1.5 cm firm pedicular localised pigmented villonodular synovitis originating from the insertion of the anterior horn of the medial meniscus. Owing t...

Orthopedic screw removal has proven itself to be a challenge. Access to a Screw Removal Set (TM Synthes) is essential. But what options are available when it cannot remove a broken screw in a lesser toe on a background of osteomyelitis of a lesser toe? A young healthy patient had undergone a 2nd and 3rd toe proximal interphalangeal joint (PIPJ) and distal interphalangeal joint (DIPJ) fusion usi...

Many of the papers studying the screw-drive system dynamic model concentrated on the control methodologies that is why vibrational models are either simple lumped models or simplified flexible beam models. In this paper a screw-drive system dynamic model and its vibrations are discussed. The screw is considered as an EulerBernoulli type flexible beam with fixed-free boundary conditions and the ...

BACKGROUND Intraoperative monitoring of motor evoked potentials by transcranial electric stimulation is popular in neurosurgery for monitoring motor function preservation. Some authors have reported that the peg-screw electrodes screwed into the skull can more effectively conduct current to the brain compared to subdermal cork-screw electrodes screwed into the skin. The aim of this study was to...

BACKGROUND This study aimed to evaluate the clinical efficacy of use of a 3D printing guide plate in posterior lumbar pedicle screw fixation. MATERIAL AND METHODS We enrolled 43 patients receiving posterior lumbar pedicle screw fixation. The experimental group underwent 3D printing guide plate-assisted posterior lumbar pedicle screw fixation, while the control group underwent traditional x-ray-...

In situ stabilization remains the standard of care in the treatment of stable slipped capital femoral epiphysis (SCFE). Screw placement perpendicular to the physis has shown satisfactory results with minimal complications. A prominent screw head may produce femoral acetabular impingement and pain after in situ fixation in severe SCFE. We performed a biomechanical study to establish whether scre...

BACKGROUND Some nonstemmed hip systems have been developed to avoid stress shielding and aseptic loosening, which are major drawbacks of stemmed hip arthroplasty. Without the stem, the cup over the femoral head can be stabilized by anatomic fitness of the cup interior and mechanical fixation of the auxiliary screws. METHODS Using finite-element method, neck-shaped systems with two bone-cup fi...

The Z-effect phenomenon is a potential complication of two lag screw intramedullary nail designs used for fixation of intertrochanteric hip fractures, in which the inferior lag screw migrates laterally and the superior lag screw migrates medially during physiologic loading. The current investigation was undertaken in an attempt to reproduce the Z-effect phenomenon in a laboratory setting. Sixte...

Co-rotating twin screw extruders are extensively used in the polymer compounding industry mainly due to their good mixing capacity. Given its modular construction, this type of machines can easily be adapted to work with different polymeric systems, e.g., polymer blends, nanocomposites or highly filled polymers. Nevertheless, the performance of these machines is strongly dependent on the screw ...