The association of decompression and fusion with improved patient-reported outcome measures in patients with degenerative spondylolisthesis and a hypolordotic lordosis distribution index when compared with decompression alone.

OBJECTIVE

The aim of this study was to compare patient-reported outcome measures among patients with degenerative lumbar spondylolisthesis (DLS) who underwent either decompression alone (DA) or decompression and fusion (DF) stratified by preoperative lumbar lordosis distribution index (LDI).

METHODS

Patients with DLS from 2 of the 7 centers enrolled in the Canadian Spine Outcomes and Research Network prospective study between 2015 and 2022 were retrospectively analyzed. Patients were stratified into an LDI < 50% and an LDI 50%-80% cohort, and whether they underwent DF or DA. Radiographic parameters were obtained from preoperative radiographs and included global lumbar lordosis, lower lumbar lordosis, and the LDI. The primary outcomes included achieving the minimal clinically important difference (MCID) for the numeric rating scale (NRS) score for back pain, the NRS score for leg pain, and the Oswestry Disability Index (ODI) at 24 months postoperatively.

RESULTS

One hundred seventy-nine patients were available for analysis. There were 73 patients with a preoperative LDI < 50% (32 with DA, 41 with DF), while 106 patients had a preoperative LDI 50%-80% (51 with DA, 55 with DF). In the LDI < 50% group, the MCID for back pain was achieved at 24 months in significantly more patients with DF than with DA (85.7% vs 48.3%, p = 0.002) and for the ODI (91.4% vs 62.1%, p = 0.006). These differences were not observed in the LDI 50%-80% group. After multivariate analysis, in the LDI < 50% cohort DF was associated with improved odds of achieving the MCID at 24 months for back pain (OR 12.614, 95% CI 1.899-83.767; p = 0.009) and ODI (OR 10.479, 95% CI 1.423-77.156; p = 0.021) scores compared to DA. These differences were not found in the LDI 50%-80% cohort.

CONCLUSIONS

In patients with DLS, a preoperative LDI < 50% may be helpful in identifying those who may benefit from DF over DA.