# Etiologies and Outcomes in Revision Lumbar Surgery: A Single-Center Cohort Study of Patients Undergoing Two or More Revisions

## TL;DR

This study examines why patients need multiple lumbar spine surgeries and finds that infection is the main cause, with outcomes still showing improvement despite repeated procedures.

## Contribution

The study identifies infection as the primary cause of multiple revision lumbar surgeries and shows functional improvements despite increased surgical complexity.

## Key findings

- Infection was the leading cause of repeated surgeries, increasing from 7.5% to 63% by the second revision.
- Functional outcomes improved significantly after each surgery, with better ODI and VAS-LP scores postoperatively.
- Infection-related cases had the shortest interval between surgeries (~1.3-1.5 years).

## Abstract

Introduction

The incidence of revision lumbar spine surgery has increased with the growing number of spinal procedures performed worldwide. Patients requiring multiple revisions represent a complex subgroup with higher complication risks and variable outcomes. This study aimed to identify the primary etiologies leading to repeated lumbar spine surgeries and to evaluate associated clinical outcomes.

Materials and methods

This single-center retrospective cohort study included 66 patients who underwent at least two revision lumbar spine surgeries (three total procedures including the index) between January 2017 and January 2022. Demographic, operative, and clinical data were extracted from hospital records. Functional outcomes were assessed using the modified Oswestry Disability Index (ODI) and Visual Analogue Scale for leg pain (VAS-LP) before and after each surgery. Statistical analysis included repeated-measures tests and Kaplan-Meier survival analysis using IBM SPSS Statistics for Windows, Version 25 (Released 2017; IBM Corp., Armonk, New York, United States).

Results

Among 66 patients undergoing at least two revision lumbar spine surgeries, infection was the predominant etiology, increasing from 7.5% at the index surgery to 63% by the second revision. Adjacent segment degeneration and implant failure accounted for 25% and 4.5% of cases, respectively. The mean interval between the index and first revision was approximately 3.6 years, which shortened to 1.9 years between the first and second revisions; infection-related cases showed the fastest recurrence (~1.3-1.5 years). Functional outcomes demonstrated significant improvement across all stages, with mean ODI and VAS-leg pain (VAS-LP) scores improving postoperatively (p < 0.001, repeated-measures analysis).

Conclusion

Infection was the leading cause of repeated lumbar spine surgeries and correlated with progressively shorter revision intervals. Despite increased surgical complexity, meaningful functional and pain improvements remained achievable. Preventing infection and ensuring careful patient selection are essential for optimizing outcomes in recurrent lumbar spine surgery.