Ligament graft fixation with bioabsorbable interference screws is a standard procedure in cruciate ligament replacement. Previous screw designs may resorb incompletely, and can cause osteolysis and sterile cysts despite being implanted for several years. The aim of this study was to examine the in vivo degradation and biocompatibility of the new Milagro interference screw (Mitek, Norderstedt, G...

A preliminary study of Acoustic Emission during orthopaedic screw fixation was performed using polyurethane foam as the bone-simulating material. Three sets of screws, a Dynamic Hip Screw, a small fragment screw and a large fragment screw were investigated, monitoring acoustic emission activity during the screw tightening. Some specimens were overtightened on purpose to investigate the possibil...

Impregnation of antimicrobial agents within biodegradable orthopedic implants provides a possibility for local antimicrobial prophylaxis of biomaterial-related infections. The objective of this study was to evaluate the efficacy of a bioabsorbable ciprofloxacin containing bone screw (Ab-PLGA) in the prevention of biomaterial-related infection due to Staphylococcus aureus in a rabbit model. Anim...

A global study of geometry and material properties of orthopedic screws was performed, considering not only the effect of each single factor (screw pitch, number of threads, fillet angle, etc.) but also their interactions with respect to bone density.The stress patterns resulting from different screw geometries and bone densities were analyzed using finite element techniques, taking into accoun...

Study Design Biomechanical study of pedicle screw fixation in osteoporotic bone. Objective To investigate whether it is better to tap or not tap osteoporotic bone prior to placing a cement-augmented pedicle screw. Methods Initially, we evaluated load to failure of screws placed in cancellous bone blocks with or without prior tapping as well as after varying the depths of tapping prior to screw ...

BACKGROUND Screw fixation of pelvic ring fractures is a common, but demanding procedure and navigation techniques were introduced to increase the precision of screw placement. The purpose of this case series was the evaluation of screw misplacement rate and functional outcome of percutaneous screw fixation of pelvic ring disruptions using a 2D navigation system. METHODS Between August 2004 an...

Purpose The purpose of this study is to analyze the relationship between significant femoral neck shortening (SFNS) and bone density after three parallel screw fixation in valgus impacted femoral neck fracture, and to analyze the risk factors for SFNS. Materials and Methods This is retrospective study of 83 patients. We performed univariate analysis for patient information, bone density, frac...

Orthodontic miniscrews are widely used as temporary anchorage devices to facilitate orthodontic movements. Miniscrew loosening is a common problem, which usually occurs during the first two weeks of treatment. Macrodesign can affect the stability of a miniscrew by changing its diameter, length, thread pitch, thread shape, tapering angle and so on. In this study, a 3-D finite element analysis wa...

AIM The aim of this systematic review and meta-analysis was to assess and compare peri-implant marginal bone loss in cement- and screw-retained prostheses. MATERIAL AND METHODS Electronic database and manual searches were undertaken to identify trials, prospective or retrospective studies reporting on radiographic marginal bone loss around dental implants restored with cement- and/or screw-re...

In this study, a new medical bone screw was designed and manufactured by Ti6Al4VELI GR23 material and tested in accordance with the ATSM F 543-02 test procedure experimentally. This test is used to measure the axial tensile force required to fail or remove a bone screw from a defined material. Concurrently, 3-D Finite Element Analysis (FEA) models of these medical bone screws were developed to ...