Suggestions for a Total Elasto-Dynamic Intervertebral Disc Prosthesis

Abstract

The essential considerations to be taken for the design of a composite elasto-dynamic intervertebral disc prosthesis (IDP) are discussed, and a disc implant, supposedly satisfying the demands for surgical and biomechanical applicability and biocompatibility, are outlined. The suggested IDP implant is composed of an elastic kernel, covered in a two-components telescoping shell, situated in a polymer slit-tube fundament, after preparation fixed to the respective vertebral bodies of the respective motion segment with bone cement. The approach to a lumbar motion segment is suggested to be by way of an abdominal and retroperitoneal incision and exploration.

A spiral implant as nucleus prosthesis in the lumbar spine

“…Finally, the segment will collapse, increasing the load on both facet joints, leading to accelerated spondylarthrosis and reduced mobility. For many decades, several attempts were made to create an efficient implant to replace the herniated or degenerated nucleus, including the concepts of a waterbladder [7], a hydrophilic elastomer [4] and a silicone polyethylene implant [5]. More or less ineffective, these implants never went into clinical studies or into routine use.…”

Explicative Cases of Controversial Issues in Neurosurgery

“…Most of these implants have been unsuccessful because of some complications such as extrusion, subsidence, and reactive endplate changes. Edeland (1981) implied that a nuclear implant should have viscoelastic features and permit influx and egress of water, thereby mimicking normal disc behaviors. The prosthetetic disc nucleus (PDN) prosthesis consist a capsule of woven polyethylene enclosing a hydroscopic thixotropic gel.…”

A Historical Review and Current Perspective on the Intervertebral Disc Prosthesis

“…Edeland (33,34) proposed using a composite viscohydraulic concept that would create an intrinsic preloading of the annular polymer, redefine the instantaneous axes of rotation and reduce stresses at the bone implant interfaces. To date, no clinical evidence is available to demonstrate the durability of the hydraulic systems or biomechanics of viscoelastic-metal interfaces.…”

“…Only one these models have been subjected to clinical trials with promising outcomes. The SB Charite III Prosthesis (Fig 1), developed by Buttner-Janz and colleagues, is a modular system (33)(34)(35)(36)(37). It consists of two end plates of cobalt-chromium alloy and a polyethylene sliding core that reproduces near normal segment mobility.…”