The effect of hydroxyapatite on titanium pedicle screw resistance: an electrical model.

Background Context: Intraoperative detection of a pedicle wall breach implicitly reduces surgical risk, but the reliability of intraoperative neuromonitoring has been contested. Hydroxyapatite (HA) has been promulgated to increase pedicle screw resistance and negatively influence the accuracy of electromyography.

Purpose: The primary purpose of this experiment is to evaluate the effect of HA on pedicle screw electrical resistance using a controlled laboratory model.

Pedicle morphometry in the upper thoracic spine: limits to safe screw placement in older patients.

Study Design: An anatomic study of pedicle dimensions and orientation was performed for upper thoracic vertebrae from elderly human subjects.

Objectives: To quantify dimensions of thoracic pedicles, and to determine the potential for safe transpedicular screw fixation in the upper thoracic spine.

Summary Of Background Data: Clinical and anatomic reports support thoracic pedicle fixation as a safe, effective alternative to hook fixation in both normal and osteoporotic bone.

Four year experience with the AO Anterior Thoracolumbar Locking Plate.

For decades spinal surgeons have attempted to design simple, single stage anterior internal fixation systems for the thoracic and lumbar spine. Early devices presented both biomechanical and technical problems. The AO Anterior Thoracolumbar Locking Plate (ATLP) was designed to solve some of the problems encountered with early anterior instrumentation.

Management of metastatic tumors to the spine using simple plate fixation.

Frequency of metastasis to the spine in the population of patients suffering from malignant disease is a significant clinical problem, as these patients present with intractable pain and neurologic impairment. The sequelae of metastatic tumors to the spinal column significantly decrease the quality of the patient's life. With the advent of modern chemotherapeutic regimens in metastatic disease, patients with metastatic tumors are living longer and more productive lives.

Extracoelomic approach to the spine.

A modified transthoracic approach to the thoracic vertebral column is described. In this method, the parietal pleura is detached from the chest wall and retracted with the visceral pleura and its contents. A direct approach to the vertebral bodies is thus achieved without transgression of the intrapleural space.