| This thesis has examined a broad range of issues encountered in the design and development of a prosthetic intervertebral disc. A number of the issues such as biocompatibility, load capacity, durability, and range of motion have been considered in the current literature. However, general strategies for dealing with many of these issues have not been developed in the literature, and the importance of some issues, such as load transfer, have only been mentioned without serious attempts at quantification. Current literature concerning design and development of three general classes of spinal orthopedic implants was reviewed. These classes of spinal implants are vertebral body replacements, disc nucleus replacements, and disc cartilage replacements. This thesis has also (1) presented the first synthesis of detailed design criteria for a flexible polymeric PID device based on published mechanical test data for natural discs and on knowledge of the operating environment, (2) identified suitable materials for prototypes, (3) identified and implemented a process for making prototypes, (4) provided the first description in the literature of the effects of a simulated physiological environment on the mechanical properties of a PID, (5) documented the compressive strength of the PID without interfacial bonding between the fiber and matrix, (6) demonstrated that the compressive strength of the braided PID is minimally effected by a wet service environment, (7) presented the first comparison of damping capabilities of a PID with the NID, (8) demonstrated the design of a PID with both modulus and damping capabilities similar to the natural disc, (9) presented the only closed form analytical model in the literature for predicting braided or woven PID behavior, and (10) tested the biocompatibility of the polyurethane/polyaramid PID material. |
