Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)




M. Scott De Berard


Lumbar degenerative disc disease is a remarkably common condition among patients presenting with chronic low back pain and physical disability. When a surgical treatment option is warranted, patients now have the option of undergoing lumbar total disc replacement (TDR), a relatively new procedure that is designed to replace lumbar fusion, the traditional surgical intervention for degenerative disc disease. The lumbar TDR procedure has demonstrated clinical efficacy equivalent to that of lumbar fusion, although concern remains about the longevity, safety, and costs related to the procedure. These issues were addressed in three separate observational studies using administrative claims data. The first study estimated the revision burden and economic revision burden of lumbar TDR. The second study examined the lumbar TDR hybrid procedure, where both a lumbar TDR and lumbar fusion are performed simultaneously. No observational data have been reported on the frequency, cost, and diagnostic indications related to the TDR hybrid procedure. The third study mapped the geographic variation of procedural rates of lumbar TDR. Previous research has found substantial geographic variation in lumbar spine surgery rates and a similar analysis of lumbar TDR variation has yet to be reported. The present series of studies found the revision burden and economic revision burden of lumbar TDR to be similar to data reported for this procedure from the mid-2000s, though the overall occurrence of the procedure appears to have declined. The economic revision burden made this a lower-cost procedure than lumbar fusion, with a tradeoff in terms of revision burden being higher for lumbar TDR. The lumbar TDR hybrid procedure was found to make up approximately 16% of the total number of TDR procedures, involving much higher costs than a single-level TDR procedure. Finally, geographic variation of the procedural rate of lumbar TDR varied dramatically across the U.S., surpassing the variation observed in lumbar fusion surgery. Limitations of the observational data used in these studies are described. Recommendations for future observational research are offered as well. Finally, implications for these studies on practice guidelines and reimbursement policies are provided.