Long-Term Impact of Adolescent Idiopathic Scoliosis Surgery Using Harrington Instrumentation on Quality of Life

Harrington instrumentation was the first widely adopted technique for the surgical correction of adolescent idiopathic scoliosis (AIS). While effective for coronal-plane correction, it has been superseded by modern systems because of long-term complications, particularly sagittal malalignment and flatback syndrome. This study aimed to evaluate the long-term impact of AIS surgery using Harrington instrumentation on health-related quality of life (HRQoL) and to analyse associations between radiographic parameters and patient-reported outcomes, with a minimum follow-up of over 25 years.

This single-centre observational cohort study included 142 patients with AIS who underwent surgical correction with Harrington instrumentation between 1971 and 1997. At long-term follow-up, all patients underwent a standardised clinical examination and standing full-spine radiographs in posteroanterior and lateral projections. Spino-pelvic and global sagittal alignment parameters were measured using Surgimap software (Globus Medical, Inc., Audubon, Pennsylvania, USA). HRQoL was assessed using the Oswestry Disability Index (ODI), Scoliosis Research Society–22r (SRS-22r), and EQ-5D-5L questionnaires. Correlations between radiographic parameters, extent of instrumentation, and HRQoL outcomes were analysed using appropriate parametric and non-parametric statistical tests (p ≤ 0.05).

Overall, HRQoL scores indicated favourable long-term outcomes. A significant association was observed between EQ-5D-5L scores and lumbar lordosis (p = 0.027). ODI scores were significantly associated with pelvic tilt (p = 0.026), T1 pelvic angle (p = 0.005), sagittal vertical axis (p = 0.033), and thoracolumbar/lumbar curve magnitude (p < 0.001).

No statistically significant associations were found between the number of instrumented vertebral levels and ODI (p = 0.509), EQ-5D-5L (p = 0.378), or SRS-22r (p = 0.113). Similarly, no significant differences were observed between groups defined by upper or lower instrumented vertebrae in ODI, EQ-5D-5L, or SRS-22r scores.

No statistically significant associations were found between gender and ODI (p = 0.046), EQ-5D-5L (p = 0.117), or SRS-22r (p = 0.046). Likewise, patient age at follow-up was not significantly associated with ODI (p = 0.388), EQ-5D-5L (p = 0.883), or SRS-22r (p = 0.223).

More than 25 years after surgery with Harrington instrumentation for AIS, patients maintain a preserved quality of life, with predominantly mild pain and functional limitations. Sagittal alignment parameters, particularly pelvic tilt, T1 pelvic angle, and thoracolumbar/lumbar curve magnitude, are important predictors of functional outcome. The extent of spinal fusion does not significantly influence long-term quality of life.