Surgical Practice Variation and Outcomes Regarding Single-Level Posterior Approach for Degenerative Lumbar Spondylolisthesis: A Canadian Spine Outcomes Research Network (CSORN) Study.

Background context: Symptomatic degenerative lumbar spondylolisthesis (DLS) is a common pathology for spinal surgery. Due to the high surgical volume and variability in management approaches, analyzing and understanding practice patterns is essential for improving patient care PURPOSE: To investigate the extent of surgical practice variation in the treatment of Meyerding Grade I DLS among Canadian spine centers and compare outcomes between decompression alone and decompression with instrumented fusion.

Study design: We conducted a multicenter retrospective review of collected data on consecutive spine surgery patients enrolled by the Canadian Spine Outcomes and Research Network (CSORN) between January 2015 to December 2023.

Patient sample: Adults (≥18 years) surgically treated for a primary diagnosis of Grade I DLS presenting with radiculopathy or neurogenic claudication and managed with single-level posterior lumbar decompression, with or without instrumented arthrodesis.

Outcome measures: significant improvement in all PROMs at 3 months, 12 months and 24 months (p < 0.001). At the 12-month and 24-month mark, the decompression and instrumented arthrodesis group showed a higher EQ-5D score (0.23 vs 0.17, p = 0.119) but not statistically significant.

Methods: Patients aged 18 or older who were surgically treated for a primary diagnosis of Meyerding Grade I DLS with a chief complaint of radiculopathy or claudication and treated with single-level posterior lumbar spinal decompression with or without instrumented arthrodesis with pedicle screw fixation were included in this study. A total of 548 patients met the inclusion criteria, of which 171 patients (31.2%) underwent decompression alone and 377 patients (68.8%) underwent decompression with instrumented arthrodesis.

Results: Postoperatively, both groups showed significant improvement in all PROMs at 3 months, 12 months and 24 months (p < 0.001). At the 12-month and 24-month mark, the decompression and instrumented arthrodesis group showed a higher EQ-5D score (0.23 vs 0.17, p = 0.119) but not statistically significant. The decompression and instrumented arthrodesis group showed a higher rate of perioperative AEs (17.1% vs 9.4%, p = 0.029) and had a significantly longer hospital stay (3.68 days vs 1.25 days, p < 0.001). No reoperations were needed after alone decompressions.

Conclusions: There was no significant practice variability between the Canadian Provinces for the surgical treatment of grade I DLS with spine centers in New Brunswick, Quebec, Ontario, Manitoba, Saskatchewan, Alberta and British Columbia performing decompression and instrumented arthrodesis. Overall, there was no significant difference between centers in the West and in the East (p = 0.262), with both Western and Eastern centers generally performing more decompression and instrumented arthrodesis.