Thoracic cortical bone trajectory (CBT) screw fixation can maximize the thread contact with cortical bone, and it is 53.8% higher than that of the traditional pedicle screws. Moreover, it can also enable less tissue dissection and retraction for reduced muscle disruption.Eighty pediatric patients are divided into 4 age groups and their thoracic vertebrae are analyzed on computed tomography (CT)...

For osteosynthesis and for bone transplant fixation in particular, a lag screw with a biconcave washer, the so called "Anchor Screw" (AS) has been introduced in maxillo-facial surgery. Using 2D-finite element analysis (FEA), the v. Mises and the circumferential stresses induced in underlying bone by this AS are analysed and compared to those under a conventional lag screw. The stress distributi...

Several papers in this issue of the Journal address topics in the theme of plate and screw fixation (1–4). A critical element of this form of internal fixation is that the maintenance of stability provided by the plate relies heavily on the integrity of the screw fixation. Bone screws can perform their work in several ways. In conventional plate fixation, the head of a tightened screw compresse...

Study Design Cohort study. Objective Expandable anterolateral plates facilitate the reduction of posttraumatic deformities of thoracolumbar spine injuries and are commonly used in cases of unstable injuries or compromised bone quality. In this in vitro study, the craniocaudal yield load of the osseous fixation of an anterior angular stable plate fixation system and the effect of polymethyl meth...

BACKGROUND The pullout strength of pedicle screws is influenced by many factors, including diameter of the screws, implant design, and augmentation with bone cement such as PMMA. In the present study, the pullout strength of an innovative fenestrated screw augmented with PMMA was investigated and was compared to unaugmented fenestrated, standard and dual outer diameter screw. METHODS Twenty f...

Endoscopic (single-incision) anterior cruciate ligament (ACL) reconstruction with bone patellar tendon bone can usually be secured with interference screws on the femur and tibia. Infrequently, patella alta, which results in a longer tendinous component of the graft construct, can result in construct mismatch, resulting in a large portion of the tibial bone plug extruding from the tibial tunnel...

Four patients underwent stabilization surgery using both bilateral C2 pedicle screw (PS) and intralaminar screw (LS). Neural and vascular injury resulting from incorrect screw placement was assessed using computed tomography (CT). The evaluation of bone union was assessed by lateral flexion-extension X-ray films and CT. The symptoms were improved in all patients. There were no intraoperative co...

We report a case of fixation of a scaphoid fracture using an Acutrak(®) screw. This screw is cannulated and headless, which allows it to be implanted below the surface of the bone. It uses the same concept of variable thread pitch as the Herbert screw, but unlike the Herbert screw, is fully threaded, with continuously varying pitch along its length. This variable pitch creates constant compress...

STUDY DESIGN Clinical case series. PURPOSE In the posterior lumbar interbody fusion (PLIF) procedure in our institute, the cephalad screw trajectory follows a mediolateral and caudocephalad directed path according to the original cortical bone trajectory (CBT) method. However, the starting point of the caudal screw is at the medial border of the pedicle on an articular surface of the superior...

This study aimed to present the mechanical performance evaluation of the dynamic hip screw (DHS) for trochanteric fracture by means of finite element method. The analyses were performed based on stainless steel and titanium implant material definitions at various stages of bone healing and including implant removal. The assessment of the mechanical performance used two parameters, von Mises str...