Perioperative Outcomes Following Single-Stage Surgery for Tandem Spinal Stenosis-A Single-Center Retrospective Cohort

Objectives: Tandem spinal stenosis (TSS) is often underdiagnosed and traditionally managed with multi-stage surgery (MSS). Single-stage surgery (SSS) is an alternative, but prior studies largely emphasize younger, healthier patients. This study evaluated perioperative and functional outcomes after SSS for TSS in a surgically diverse cohort. Methods: A retrospective chart review included 20 patients who underwent SSS for TSS at a single academic institution. Mean age was 63.75 years, and median modified frailty index was 2. Etiologies included degenerative, traumatic, and neoplastic disease across cervical, thoracic, and lumbar regions. Outcomes included operative characteristics, complications, readmissions, and functional recovery measured by Visual Analog Scale (VAS) pain and modified Japanese Orthopaedic Association (mJOA) scores. Results: The mean number of operated levels was 5.2, mean operative time was 232.4 min, total OR time was 355.1 min, and length of stay was 6.9 days. Surgical complications occurred in 15% of patients, medical complications in 25%, and 90-day readmission in 15%, with no 30-day mortality. Mean mJOA improved from 12.86 at baseline to 16.08 at first follow-up and 16.46 at 3 months; REML mixed-effects modeling showed a significant timepoint effect (F (4, 34.55) = 9.15, p < 0.001), with significant Sidak-adjusted improvement at both timepoints. VAS pain showed no significant longitudinal effect. Conclusions: SSS for TSS appears feasible in a real-world, surgically diverse cohort including older and moderately frail patients. These findings support individualized SSS candidacy assessment.