Epidemiology of indications and contraindications to total disc replacement in an academic practice.

BACKGROUND CONTEXT

Given the experience with anterior lumbar cages, the similar enthusiasm for total disc replacement (TDR) and the economic incentives driving use of this new technology, it is important to document reasonable expectations as to the incidence of patients with appropriate indications for this new technology.

PURPOSE

To document epidemiological data for the indications and contraindications to total disc replacement (TDR) to guide expectations for use of this new technology. STUDY DESIGN/SETTINGS: Retrospective evaluation of contraindications and indications for lumbar TDR in consecutive symptomatic patients presenting to an academic spine practice.

PATIENT SAMPLE

Six hundred twenty-seven consecutive symptomatic patients presenting to an academic spine service.

OUTCOME MEASURES

Presence of contraindications to lumbar TDR based on Food and Drug Administration criteria.

METHODS

Over a year, 627 new patients were evaluated by the only orthopedic spine surgeon on faculty at a major university. 131 underwent lumbar surgeries. Surgical patients were divided into Group 1 (57 patients who had fusions) and Group 2 (74 patients who had nonfusion surgeries). The incidence (period prevalence) and prevalence (point prevalence) of indications for and contraindications to TDR were documented.

RESULTS

The incidence of indications for TDR was 0.5% (3/627). The prevalence of no contraindications to TDR in the fusion Group 1 was 5% (3/57). Overall, 9% (3 fusion and 9 nonfusion) had no contraindications to TDR and the same percentage satisfied indications for TDR. However, 96% (71/74) of Group 2 patients considered themselves satisfied with laminectomies and laminotomies. The combined average number of contraindications to TDR was 2 (SD, 1.33) (range, 0-6). For Group 1, it was 3 and 1 for Group 2 (p<.5).

CONCLUSIONS

Despite early enthusiasm for TDR replacing fusion, there was only a 0.5% incidence of indications for TDR in the overall population and a 5% prevalence in the fusion patients, but the majority were in young patients who averaged about 38 years old. The absence of contraindications for TDR did not equate to indications for TDR because other nonfusion techniques exist. Based on the history of the introduction of other new spinal technologies and the fact that the current criteria for TDR seems to result in a relatively small number of eligible patients, there is risk of overuse of this new technology.