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 ...

This paper presents a finite element (FE) model to identify parameters that affect the performance of an improved cancellous bone screw fixation technique, and hence potentially improve fracture treatment. In cancellous bone of low apparent density, it can be difficult to achieve adequate screw fixation and hence provide stable fracture fixation that enables bone healing. Data from predictive F...

BACKGROUND CONTEXT Achieving solid implant fixation to osteoporotic bone presents a clinical challenge. New techniques and devices are being designed to increase screw-bone purchase of pedicle screws in the lumbar spine via a novel cortical bone trajectory that may improve holding screw strength and minimize loosening. Preliminary clinical evidence suggests that this new trajectory provides scr...

BACKGROUND It was reported that expansive pedicle screw (EPS) and polymethylmethacrylate-augmented pedicle screw (PMMA-PS) could be used to increase screw stability in osteoporosis. However, there are no studies comparing the two kinds of screws in vivo. Thus, we aimed to compare biomechanical and interfacial performances of EPS and PMMA-PS in osteoporotic sheep spine. METHODOLOGY/PRINCIPAL F...

BACKGROUND Efforts to select the appropriate number of implants in adolescent idiopathic scoliosis (AIS) instrumentation are hampered by a lack of biomechanical studies. The objective was to biomechanically evaluate screw density at different regions in the curve for AIS correction to test the hypothesis that alternative screw patterns do not compromise anticipated correction in AIS when using ...

BACKGROUND Conventional screws used for fracture fixation in orthopedic surgery continue to rely on the historic buttress thread design. While buttress screws generally provide solid resistance against unidirectional axial loading forces, their design suffers from several limitations, as the buttress thread does not adequately resist multiaxial forces. Furthermore, the buttress screw is prone t...

OBJECTIVE To compare biomechanical strength, interface quality, and effects of bone healing in bone-implant interfaces that were untreated or treated with calcium phosphate cement (Ca-cement), magnesium phosphate cement (Mg-cement), or polymethylmethacrylate (PMMA) in horses. ANIMALS 6 adult horses. PROCEDURES 4 screw holes were created (day 0) in each third metacarpal and third metatarsal ...

OBJECTIVE To investigate the feasibility of C1 lateral mass screw and C2 pedicle screw with polyaxial screw and rod system supplemented with miniplate for interlaminar fusion to treat various atlantoaxial instabilities. METHODS After posterior atlantoaxial fixation with lateral mass screw in the atlas and pedicle screw in the axis, we used 2 miniplates to fixate interlaminar iliac bone graft ...

BACKGROUND There have been numerous studies conducted to investigate the pullout force of pedicle screws in bone with different material properties. However, fewer studies have investigated the region of effect (RoE), stress distribution and contour pattern of the cancellous bone surrounding the pedicle screw. METHODS Screw pullout experiments were performed from two different foams and the c...