Radiographic Robustness of Lumbar Interbody Fusion Techniques

Abstract

Study design: Retrospective chart review.

Objectives: Lumbar interbody fusion (LIF) can be achieved with various techniques. Evidence supporting the long-term clinical advantages of one technique over another are inconclusive. The purpose of this study was to (1) determine the changes in sagittal parameters in the preoperative, intraoperative, and post-operative phase, (2) evaluate the radiographic maintenance of these parameters over time, and (3) compare the demographics and patient reported outcomes of patients undergoing various LIF techniques.

Methods: We performed a retrospective chart review of patients with degenerative spine disease undergoing single level anterior (ALIF), lateral (LLIF), posterior (PLIF), or transforaminal (TLIF) lumbar interbody fusion. Data collected included patient demographics and diagnosis at time of surgery. Upright lumbar radiographs taken pre-operatively, intra-operatively, and post-operatively were measured for lumbar lordosis (LL), segmental lordosis (SL), posterior disc height (PDH), and foraminal height (FH).

Results: 194 patients in a single center were included. PDH and FH increased intra-operatively following ALIF (P < .0001), PLIF (P < .0001), LLIF (P < .0001), and TLIF (P < .0001). SL also increased intra-operatively for ALIF (P = .002) and LLIF (P = .0007). Compared to intra-operative radiographs, PDH and FH decreased at latest post-operative phase for ALIF (P < .03), LLIF (P < .003), TLIF (P < .001), and PLIF (P < .005). SL decreased for ALIF (P = .0008), and TLIF (P = .02). LL did not change postoperatively across techniques. Patient reported outcomes improved post-surgically and disability index decreased, but neither differed between techniques.

Conclusion: LIF, regardless of technique, was shown to provide significant radiographic changes in PDH and FH. Techniques utilizing larger intervertebral cage sizes (ALIF/LLIF) improved SL. Single level LIF did not affect overall LL. No single technique displayed superior radiographic robustness over time.

Keywords: degenerative disc disease; lumbar; lumbar interbody fusion; spinal fusion; x-rays.

Figure 1.

Radiographic measurements. Schematic demonstrating measurements taken on upright lateral lumbar x-rays. All segment level measures (SL, FH, PDH) were taken at the spinal level operated on, but are separated in the image for illustrative purposes.

Figure 2.

Changes in radiographic parameters after lumbar interbody fusion. (A) Lumbar lordosis. (B) Segmental Lordosis. (C) Posterior Disc Height. (D) Foraminal Height. Data plotted as mean ± SD. Paired t test, *P < .05.