Introduction to lumbar total disc replacement: Factors that affect tribological performance

Total disc arthroplasty offers both theoretical and practical advantages over fusion surgery as a treatment for low back pain. In the majority of cases, these relatively new devices owe much of their evolution to the success of other total joint replacements, in particular, hip and knee prostheses, which have been developed over the last four decades. The demands on these new joints are substantial, and although short-term data appear to demonstrate good outcomes in a significant proportion of patients, medium- and longer-term results are sparse. The wear performance of these devices should be emphasized as a possible cause of failure through both adverse biological reactions, such as osteolysis, and inappropriate biomechanics, similar to that observed in a small proportion but numerically significant number of hip and knee prostheses. This article reviews the current technology in terms of the performance parameters these devices are required to operate within and the evidence for future problems akin to those observed in other joint arthroplasties. The article calls for more rigorous preclinical testing and follow-up protocols, based on the technologies and procedures developed for the current range of conventional hip and knee replacements.