Effects of Adding a Cross-Link During Single-Level Lumbar Interbody Fusion for Degenerative Lumbar Spine Diseases: A Computed Tomography-Based Analysis.

STUDY DESIGN: Retrospective study. OBJECTIVES: To evaluate whether adding cross-links during single-level lumbar interbody fusion (LIF) improves fusion rates, segmental alignment, and clinical outcomes. SUMMARY OF BACKGROUND DATA: Biomechanical studies suggest cross-links enhance rotational stability in single-level posterior lumbar interbody fusion, but clinical evidence for their benefit in degenerative lumbar spine diseases remains limited. No previous clinical study has investigated how cross-link addition affects LIF outcomes. METHODS: One hundred thirty-one patients underwent single-level LIF for degenerative lumbar spine diseases (2012-2022) and were categorized into cross-link (CL, n=64) and non-cross-link (NCL, n=67) groups. Researchers assessed CT-based fusion parameters (interbody and facet fusion rates), segmental alignment measurements (segmental lordosis, disk height, and coronal tilt), and clinical outcomes (JOA and VAS scores) over a minimum 1-year follow-up. Propensity score matching minimized selection bias. RESULTS: One-year interbody fusion rates were comparable between groups (CL: 72.1% vs. NCL: 69.1%, P=0.839). No significant differences were found in facet fusion rates (CL: 37.7% vs. NCL: 30.9%, P=0.558), pedicle screw loosening (CL: 8.2% vs. NCL: 16.4%, P=0.254), or cage subsidence (CL: 9.8% vs. NCL: 9.1%, P=1.000). Clinical outcomes improved similarly in both groups based on final JOA scores (CL: 26.0±6.8 vs. NCL: 25.3±4.3, P=0.47) and VAS back pain scores (CL: 21.8±20.8 vs. NCL: 22.9±22.7, P=0.79). Propensity score-matched analysis of 32 patients per group confirmed these findings. CONCLUSIONS: Routine use of cross-link in single-level LIF does not improve radiographic or clinical outcomes after 1 year. A selective approach could reduce costs while maintaining excellent patient outcomes.