PURPOSE OF THE STUDY To compare the anchorage strength of Socon CS cannulated pedicle screws (B. Braun, Aesculap) with that of Socon screws in human cadaver vertebrae, using pull-out strength testing. MATERIAL Twelve samples involving T12 to L3 vertebrae were prepared and a total of 20 pedicle screws, 10 Socon CS and 10 Socon screws, were inserted in them. All screws were 55 mm in length and 6 ...

BACKGROUND Empty screw holes after hardware removal are stress risers that weaken bone and can lead to refracture in an active individual. We sought to reduce these stress risers. We hypothesize that resorbable screws used as hole fillers would (1) provide immediate strength and (2) maintain this strength during resorption. METHODS Randomized, prospective controlled animal laboratory study wi...

Purpose. To investigate the clinical abstractnd radiographic outcome of multi-axial expandable pedicle screws (MEPS) in patients with osteoporosis. Methods. One hundred and twenty-!ve consecutive patients received MEPS from the UPASS spinal !xation system to obtain thorocolumbar or lumbosacral stabilization. All patients underwent bone mineral density (BMD) scans. "e indications for use of the ...

Under normal conditions, loading activities result in microdamage in the living skeleton, which is repaired by bone remodeling. However, microdamage accumulation can affect the mechanical properties of bone and increase the risk of fracture. This study aimed to determine the effect of microdamage on the mechanical properties and composition of bone. Fourteen male goats aged 28 months were used ...

INTRODUCTION: Bone conserving designs, such as hip resurfacings, are an alternative treatment option to conventional total hip arthroplasty (THA) in young, active patients. Previous studies have shown that medullary fixation can result in significant proximal bone resorption through stress shielding [1,2], while it has been suggested that hip resurfacing arthroplasty will load the proximal femo...

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...

STUDY DESIGN Axial pullout tests using fresh cadaveric thoracolumbar vertebral bodies. OBJECTIVES To evaluate the effect of a new injectable calcium phosphate cement on the axial pullout strength of both revised and augmented pedicle screws in comparison with polymethyl methacrylate and in terms of injection method. SUMMARY OF BACKGROUND DATA Failure of pedicle screws by loosening and back ...

OBJECTIVE To determine the effect of reinforced calcium phosphate cement augmentation of the femoral neck defect created after dynamic hip screw removal in a cadaveric model. METHODS The lag screws of dynamic hip screw implants were inserted and subsequently removed in 8 matched pairs of cadaveric, osteoporotic femurs to create a femoral neck defect. One of each pair had the defect augmented ...

PURPOSE The present study was designed to compare the long-term outcome and complications of cemented versus screw-retained implant restorations in partially edentulous patients. MATERIALS AND METHODS Consecutive patients with bilateral partial posterior edentulism comprised the study group. Implants were placed, and cemented or screw-retained restorations were randomly assigned to the patien...

PURPOSE Our purpose was to determine whether a bioresorbable interference screw coated with a hydroxyapatite-based mineral layer designed to release an engineered peptide growth factor (linkBMP-2 [where "BMP-2" indicates bone morphogenetic protein 2]) improved tendon-bone healing compared with a screw without coating. METHODS Tagged linkBMP-2 peptides were used to quantify binding efficiency ...