Health-Related Quality of Life Improvements in Patients Undergoing Lumbar Spinal Fusion as a Revision Surgery

Abstract

Retrospective cohort analysis. To investigate health-related quality of life improvements in patients undergoing lumbar fusion to revise a previous lumbar spine surgery. Spinal fusion is often used as a surgical intervention in patients who have previously undergone lumbar surgery. Prior studies suggest results that are inferiorto primary fusions. However, most of these studies are based on subjective surgeon evaluations, lack patient-reported outcomes, and include various diagnoses such as prior discectomy, adjacent level degeneration, and nonunion. From a single-center database, we identified 171 patients who underwent lumbar fusion to revise a previous lumbar spine surgery. All had prospectively collected outcome measures at a minimum 2-year follow-up. The study group included 91 patients who had previous discectomy or laminectomy, 42 patients undergoing revision for adjacent segment degeneration (ASD) and 38 patients undergoing revision for nonunion. All patients completed the Oswestry Disability Index (ODI), MOS Short Form 36 (SF-36), and back and leg pain numerical rating scores before surgery and at 1 and 2 years after surgery. We compared mean changes in outcome measures and percentage of patients reaching the minimum clinically important difference (MCID) threshold in the 3 groups. Logistic regression analysis was performed to identify preoperative factors which could predict significant improvement. Statistically significant improvements were noted in back pain, leg pain, and ODI in all 3 groups. Postdecompression and ASD patients demonstrated significant improvements in SF-36 PCS at 2 years, while nonunion patients did not. A total of 49% of postdecompression patients, 38% of ASD patients, and 29% of nonunion patients reached the MCID for ODI. About 46% of postdecompression patients, 40% of ASD patients, and 24% of nonunion patients reached the MCID for SF-36 PCS. Significant improvement from index surgery was the only factor which able to predict reaching the MCID for ODI, while worker's compensation and narcotic use predicted failure to reach the MCID for SF-36 PCS. The current study demonstrates that patients undergoing lumbar fusion as a revision of a prior lumbar surgery can expect only modest improvements in health-related quality of life. Postdecompression patients achieved moderate improvements in clinical outcome measures, whereas ASD and nonunion patients showed only modest improvements. Further investigation is needed to identify preoperative predictors that will assist the selection of patients who will benefit from revision lumbar fusion.