Indirect foraminal decompression is independent of metabolically active facet arthropathy in extreme lateral interbody fusion.

Abstract

STUDY DESIGN: Retrospective analysis of prospectively collected, nonrandomized radiographical data. OBJECTIVE: To examine the relationship between the presence of preoperative metabolically active facet arthropathy (FA) and the amount of indirect foraminal decompression gained after extreme lateral interbody fusion (XLIF). SUMMARY OF BACKGROUND DATA: Although evidence of significant radiographical indirect decompression after XLIF has been shown, the relationship between the extent of indirect decompression and the presence of potentially attenuating, FA is yet to be studied. METHODS: A prospective database of consecutive patients undergoing XLIF was retrospectively analyzed. Posterior disc height, foraminal height, and cross-sectional foraminal area were measured on computed tomographic scans obtained preoperatively and 2 days postoperatively. The selected radiographical parameters were examined with respect to the presence of FA based on preoperative computed tomographic and bone scans. RESULTS: Fifty-two consecutive patients underwent 79 levels of XLIF without direct decompression. Average age was 66.4 years and 34 (65.4%) were females. Surgery resulted in significant increases in posterior disc height 3.0 to 5.7 mm (89.0% increase), P<0.0001; foraminal height 1.4 to 1.7 cm (38.0% increase), P<0.0001; and foraminal area 1.1 to 1.4 cm (45.1% increase), P<0.0001. These increases were independent of the presence of metabolically active arthropathy. CONCLUSION: Significant indirect neural decompression is possible in XLIF, regardless of the presence of metabolically active FA. LEVEL OF EVIDENCE: 3.