Does the lower instrumented vertebra matter? The impact of lower instrumented vertebra level on long-term health-related quality of life

Objective: This study aimed to investigate the relationship between the lower instrumented vertebra (LIV) level and long-term health related quality of life (HRQoL) in patients with adolescent idiopathic scoliosis (AIS) after posterior spinal fusion.

Methods: This retrospective cohort study included 120 patients who underwent posterior fusion surgery for AIS between 1991 and 2019 and had clearly identifiable fusion levels with a minimum follow-up of 5 years. In 2024, all patients completed 4 patient-reported outcome instruments, including the Scoliosis Research Society-22 revised questionnaire (SRS-22r), the Turkish version of the Spinal Appearance Questionnaire (Tr-SAQ), the Oswestry Disability Index, and the EQ-5D-3L.

Results: When outcomes were analyzed according to the level of the LIV, no significant differences in SRS-22r pain scores were observed among fusion levels up to L4. In contrast, patients with LIV at L5 demonstrated significantly lower SRS-22r pain scores than those fused to L2, L3, and L4 (P = .035). Likewise, EQ-Visual Analog Scale scores were significantly lower in the L5 group than in patients with fusion levels from L1 to L4 (P = .025).

Conclusion: In patients undergoing fusion surgery for AIS, no significant differences in quality of life scores were observed among fusion levels up to L4. In contrast, patients with fusion extending to L5 demonstrated comparatively poorer outcomes. However, the findings regarding fusion extending to L5 are based on a small subgroup and require further validation.

Cite this article as: Aydın O, Gocer B, M, Kosay C, Akcalı O, Berk H. Does the lower instrumented vertebra matter? The impact of lower instrumented vertebra level on long-term health-related quality of life. Acta Orthop Traumatol Turc. 2026; 60(5), 0762, doi: 10.5152/j.aott.2026.25762.