Four year experience with the AO Anterior Thoracolumbar Locking Plate

Abstract

For decades spinal surgeons have attempted to design simple, single stage anterior internal ®xation 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. The ATLP system is constructed in Commercially Pure titanium. It is a low pro®le device indicated for use for unstable burst fractures in the anterior column; metastatic tumor management; and degenerative diseases of the thoracolumbar spine between levels T10 and L5. Implantation of the device involves direct anterior decompression with sagittal reduction and corpectomy. This is followed by grafting reconstruction, and plate ®xation. This device has been implanted in 25 patients with an average follow-up of 38 months. There were ®ve (5) broken screws in three (3) patients, and no broken plates. Implant related postoperative complications included two misplaced screws. Preliminary results indicate that the ATLP system seems to be a safe, low pro®le, MRI/CT compatible device that provides de®nitive single stage ®xation of the anterior spinal column.

Hemilaminectomy and vertebral stabilisation for the treatment of thoracolumbar disc protrusion in 28 dogs

“…Secondly, axially loaded locking screws subjected to cantilever bending are biomechanically superior to non‐locking screws, thus reducing risk of loosening. Locking plates have been reported to be safe in the management of thoracolumbar conditions in people, including degenerative disease between T10 and L5 (Thalgott and others 1997).…”

Biomechanical analysis of a new expandable vertebral body replacement combined with a new polyaxial antero-lateral plate and/or pedicle screws and rods

“…The different implants are varying in the number of fixation points, modes of screw anchorage and number or type of screw connection (polyaxial vs. angular stable). Positive experiences with height adjustable implants lead to the development of in situ expandable and reducible plates to correct kyphotic spinal angulations or deformities after spinal tumours or fractures [31]. Encouraging results with locking plates in fracture treatment of extremities lead to the application of ''angular stable systems'' for the thoraco-lumbar spine [31].…”

Influence of Screw Positioning in a New Anterior Spine Fixator on Implant Loosening in Osteoporotic Vertebrae

“…[15][16][17][18] Huang et al analyzed various configurations of anterior vertebral double screw fixation and found that triangulation of two anterior vertebral screws (22°inter-section angle) without penetration of the cortex achieved pullout strengths similar to that of two-parallel doublecortical screws. 19 Locking-head screws act mechanically as an angular stable, unitary implant with its connecting device and have significantly increased the rigidity of unicortical screw-plate systems initially and after cyclic loading in cervical vertebrae.…”