Association Between Lenke Classification, The Extent of Lumbar Spinal Fusion, and Health-Related Quality of Life After Instrumented Spinal Fusion for Adolescent Idiopathic Scoliosis

Abstract

Study Design. Prospective cohort study. Summary of Background Data. Lenke classification is used to define the curve type in adolescent idiopathic scoliosis (AIS). The association of Lenke classification and long-term postoperative health-related quality of life (HRQoL) remains unclear. Objective. The purpose of this study was to assess the association between Lenke classification and HRQoL in patients who underwent spinal fusion for AIS. Materials and Methods. In all, 146 consecutive patients (mean age 15.1 yr) operated for AIS between 2007 and 2019 with a minimum 2-year follow-up were included. Fifty-three (36%) patients reached the 10-year follow-up. Their HRQoL was assessed with the SRS-24 questionnaire preoperatively, at six months, two years, and 10 years after surgery. Results. The preoperative major curve was the largest in Lenke 3 (mean 63°) and 4 (mean 62°) groups and the lowest in Lenke 5 groups (mean 48°, P<0.05). These curves were corrected to a mean of 15° with no differences between groups. We found no evidence of differences between the preoperative HRQoL scores between the Lenke groups. The self-image domain of SRS-24 was lower in patients with isolated major thoracolumbar scoliosis (Lenke 5) when compared with double-thoracic (Lenke 2) group at the two-year follow-up (mean [95% CI] 3.6 [3.3–3.9] vs. 4.3 [4.1–4.6]). The postoperative satisfaction domain was lower in Lenke 5 group when compared with main thoracic (Lenke 1) group (mean [95% CI] 3.8 [3.5–4.0] vs. 4.3 [4.2–4.5]) and Lenke 2 group (mean 4.4, 95% CI 4.2–4.6) at the two-year follow-up. The mean total score of SRS-24 at the 10-year follow-up was highest in Lenke 1 group (mean 4.06, 95% CI 3.79–4.33) and lowest in Lenke 6 group (mean 2.92, 95% CI 2.22–3.61). Conclusions. Lenke classification and especially its curve type (major thoracic vs. major thoracolumbar scoliosis) was associated with long-term health-related quality of life after instrumented spinal fusion for AIS.