Long-Segment Fusion of the Thoracolumbar Spine in Conjunction With a Motion-Preserving Artificial Disc Replacement

In Brief Study Design. Case report. Objective. We reviewed the case of a 44-year-old woman who underwent long-segment fusion and an artificial disc replacement. Summary of Background Data. There have been many reported advantages and disadvantages of stopping the fusion at L5, with the theoretical benefits being preserved motion, shorter operative time, allowing the remaining disc to compensate for curve correction cephalad in the lumbar spine, and a decreased likelihood for the development of a pseudarthrosis at that distal level. Methods. As the issue of the fate of the L5–S1 motion segment continues to be debated, we present the case of a medium-segment thoracolumbar fusion carried down to the L4 stable vertebra, an intervening healthy L4–L5 disc space, with the placement of an artificial disc arthroplasty at the L5–S1 level for a degenerative and discographically positive pain generator. Results. At 2-year follow-up, her L5–S1 artificial disc replacement level shows 11° range of motion and consolidated fusion from T12 to L4 with complete resolution of her axial back pain. Her T12–L4 construct is stable, and the L4–L5 level is unaffected at the latest follow-up. Her clinical outcome has been excellent with her return to a very active lifestyle. Conclusion. Artificial disc replacement below a long-segment fusion is a viable alternative to performing fusion to additional motion segments. We present a case of an L5–S1 artificial disc replacement placed below a T12–L4 adult scoliotic fusion with a “floating,” healthy L4–L5 segment that was left unfused. At 2-year follow-up, her L5–S1 artificial disc replacement level shows 11° range of motion and consolidated fusion from T12 to L4, with complete resolution of her axial back pain. Her T12–L4 construct is stable, and the L4–L5 level is unaffected at the latest follow-up. Her clinical outcome has been excellent with her return to a very active lifestyle.