Minimum Three-Year Follow-up of Specific Functional Disabilities After Multi-Level Lumbar Fusion: Comparison of Long-Level and Short-Level Fusion.

Abstract

STUDY DESIGN\nRetrospective case-control study OBJECTIVE.: To evaluate specific functional disabilities after short- and long-level lumbar fusion.\n\n\nSUMMARY OF BACKGROUND DATA\nThe Oswestry Disability Index (ODI) cannot represent all types of functional disabilities observed after lumbar fusion and a region-Specific Functional Disability Index (SFDI) is necessary.\n\n\nMETHODS\nWe examined the differences in postoperative functional disability between 81 patients who underwent ≥ 3-level lumbar fusion (group I) and 70 age- and sex-matched patients who underwent 1- or 2-level lumbar fusion (group II). The ODI and Visual Analogue Scale (VAS) were assessed pre- and postoperatively. The SFDI was assessed after lumbar fusion. We evaluated intergroup differences in postoperative VAS, ODI and SFDI scores during 3-year follow-up. Each mean score was evaluated separately for the 10 ODI and the 12 SFDI items, and we evaluated the changes observed in these scores over the 3-year follow-up.\n\n\nRESULTS\nThe mean intergroup preoperative ODI and VAS scores were similar. The mean postoperative intergroup VAS scores were similar; however, the mean postoperative ODI and SFDI scores were significantly higher in group I than in group II at 1-year (p<0.001, p<0.001, respectively) and 3-year follow-up (p\u200a=\u200a0.037, p<0.001, respectively). Among 10 ODI items, group I showed significant disability with regard to 6 items at the 1-year follow-up compared with group II, but only showed significant disability with regard to 1 item at the 3-year follow-up. Among the 12 SFDI items, group I showed significant disability with regard to all 12 items at 1-year follow-up compared with group II, as well as significant disability with regard to 9 items at 3-year follow-up.\n\n\nCONCLUSION\nThe SFDI is more sensitive than the ODI in assessing functional disabilities based on the levels of fusion. Most SFDI items indicated continued significant disability in patients with long-level lumbar fusion even 3 years postoperatively.\n\n\nLEVEL OF EVIDENCE\n3.