The purpose of this study was to understand the acoustic properties of human vertebral cancellous bone and to study the feasibility of ultrasound-based navigation for posterior pedicle screw fixation in spinal fusion surgery. Fourteen human vertebral specimens were disarticulated from seven un-embalmed cadavers (four males, three females, 73.14 ± 9.87 years, two specimens from each cadaver). Se...

BACKGROUND Medial patellofemoral ligament (MPFL) reconstruction in adults often utilizes screw fixation in the distal femur. The aim was to define the safety of similar fixation in young patients, with respect to their open physis. PURPOSE To define the age-related relationship between the femoral insertion of the MPFL and the medial aspect of the distal femoral physis on magnetic resonance i...

INTRODUCTION Technical developments for improving the safety and accuracy of pedicle screw placement play an increasingly important role in spine surgery. In addition to the standard techniques of free-hand placement and fluoroscopic navigation, the rate of complications is reduced by 3D fluoroscopy, cone-beam CT, intraoperative CT/MRI, and various other navigation techniques. Another important...

A 72-year-old patient underwent the placement of 2 screw-type implants. After 5 months the patient died of a massive stroke, and a block section of the portion of the mandible containing the implants was done. The specimen was treated to obtain thin ground sections. A 1- to 5-micron gap was present between the implant and the healing cover screw, and this space was filled by bacteria and calcul...

BACKGROUND Various lateral mass screw fixation methods have been described in the literature with various levels of safety in relation to the anterior neurovascular structures. This study was designed to radiologically determine the minimum lateral angulations of the screw to avoid penetration of the vertebral artery canalusing three of the most common techniques: Roy-Camille, An, and Magerl. ...

Volar locking plates are designed to improve and maintain anatomic alignment, even in patients with dorsal comminution and poor metaphyseal bone quality. Its widespread use led to specific complications. Most part is related to tendon, nerve and complex regional pain syndrome [1] and could be avoided by meticulous attention to detail and surgical experience [2]. Tendon and articular injury comp...

The Medoff sliding plate (MSP) is a new device used to treat intertrochanteric and subtrochanteric fractures. There are three options for sliding; either along the shaft or the neck of the femur, or a combination of both. In a prospective series of 108 consecutive displaced intertrochanteric fractures we used combined dynamic compression. The patients were followed clinically and radiologically...

Aortic injuries are devastating complications after spinal surgery. We here would like to share our experience with a successful endovascular treatment of an iatrogenic thoracic aortic injury caused by misplaced pedicle screw after spinal surgery. A patient underwent posterior spinal surgery for L1 burst fracture was transferred to our department for instrumentation removal. An iatrogenic thora...

Aim. Transpedicular screw fixation is widely used in spinal surgery. But the insertion of pedicle screws can sometimes be challenging because of the variability in pedicle size and the proximity of nerve roots. Methods. We detected intraoperatively the sensitivity for iatrogenic pedicel perforation with a hand-held electronic conductivity measurement device (ECD) that measures electrical conduc...

OBJECTIVE The purpose of the present study was to compare inter-fragmentary compression pressures after fixation of a simulated type II odontoid fracture with the headless compression Herbert screw and a half threaded cannulated lag screw. METHODS We compared inter-fragmentary compression pressures between 40- and 45-mm long 4.5-mm Herbert screws (n=8 and n=9, respectively) and 40- and 45-mm ...