STUDY DESIGN The strength effects of a pedicle screw-rod system supplemented with a novel cross-link configuration were biomechanically evaluated in porcine spines. PURPOSE To assess the biomechanical differences between a conventional cross-link pedicle screw-rod system versus a novel cross-link instrumentation, and to determine the effect of the cross-links. OVERVIEW OF LITERATURE Transve...

An important concept in bone mechanics is that osteons influence mechanical properties in several ways, including contributing to toughness and fatigue strength by debonding from the interstitial matrix so as to "bridge" developing cracks. Observations of "pulled out" osteons on fracture surfaces are thought to be indicative of such behavior. We tested the hypothesis that osteon pullout varies ...

OBJECTIVES This study aims to assess five different cortical screw types using artificial femurs, under equated testing conditions. MATERIALS AND METHODS We investigated the maximum force needed to cause deformation at screw-bone interface using fourth generation composite femurs by conducting separate pullout tests for each screw type. We normalized obtained results with traditional methods ...

OBJECTIVE To evaluate the influence of pilot hole tapping on pullout resistance and insertion torque of pedicle screws with a conical core. METHODS Mechanical tests using a universal testing machine were performed on pedicle screws with a conical core that were inserted into pedicles in the fifth lumbar vertebra of calves. The insertion torque was measured using a torque meter with a capacity...

Patients with pathologic hip fractures or impending pathologic proximal femur fractures are at a high risk for developing bone cement implantation syndrome during cemented femoral arthroplasty. Comorbid conditions of patients who sustain these fractures, including cardiopulmonary compromise and permeable, highly vascular bone related to metastatic disease, put them at risk for sudden death. Red...

Tenotomy of the long head of the biceps tendon (LHBT) is gaining popularity in shoulder surgery. We evaluated biomechanical and histological changes after tenotomy in a rabbit LHBT tenotomy model to confirm that autotenodesis is a phenomenon that occurs after the procedure. Twenty-three rabbits were included. The right shoulder was harvested from 10 randomly selected rabbits. The shoulders were...

Cancellous screws are designed to optimize fixation in metaphyseal bone environments; however, certain clinical situations may require the substitution of cortical screws for use in cancellous bone, such as anatomic constraints, fragment size, or available instrumentation. This study compares the biomechanical properties of commercially available cortical and cancellous screw designs in a synth...

Structural biological materials such as bone, teeth or mollusk shells draw their remarkable performance from a sophisticated interplay of architectures and weak interfaces. Pushed to the extreme, this concept leads to sutured materials, which contain thin lines with complex geometries. Sutured materials are prominent in nature, and have recently served as bioinspiration for toughened ceramics a...