Background:

Despite its importance for clinical decisions, the long-term consequences of posterior spinal instrumentation and fusion (PSIF) for adolescent idiopathic scoliosis (AIS), particularly in the lower lumbar spine, remain unclear. This study evaluates the long-term health-related quality of life and the need for a further surgical procedure in patients treated with Harrington instrumentation from 1961 to 1977 according to the lowest instrumented vertebra (LIV) and in comparison with age-matched norms.

Methods:

A search was performed to identify and contact the 314 identified patients with AIS treated with PSIF by Dr. L.A. Goldstein. The assessment included identified subsequent spine surgery, the Oswestry Disability Index (ODI), Scoliosis Research Society-7 (SRS-7), EuroQol-5 Dimensions (EQ-5D), and Patient-Reported Outcomes Measurement Information System-29 (PROMIS-29). The health-related quality of life was compared with U.S. norms and, within the cohort, was compared by patient factors, LIV, and subsequent spine surgery.

Results:

In this study, 134 patients (42.7%) were identified; 24 (7.6%) had died, 81 (25.8%) consented to participate in the study, and 29 (9.2%) declined participation. The mean follow-up was 45.4 years (range, 40 to 56 years). There were 81 patients who completed the surveys, 77 patients who completed the SRS-7, 77 patients who completed the ODI, and 76 patients who completed the PROMIS-29 and EQ-5D. There were 12.8% of patients with LIV L3 or proximal and 36.4% with LIV L4 or distal who had an additional surgical procedure (odds ratio, 3.98). Comparing the ODI of patients who had undergone an additional surgical procedure with those who had not showed 42% and 73% minimal disability, 53% and 23% moderate disability, and 5% and 2% severe disability. Of the patients who had not undergone an additional surgical procedure, those with LIV L3 or proximal had mean scores of 14.12 points for the ODI and 23.3 points for the SRS-7 and those with LIV L4 or distal had mean scores of 17.9 points for the ODI and 22.7 points for the SRS-7; these differences were not significant. The mean PROMIS-29 and EQ-5D scores were not different from normal U.S. age-based means.

Conclusions:

Patients with AIS treated with PSIF at a mean 45-year follow-up and LIV L4 or distal had a higher rate of undergoing an additional surgical procedure than those with LIV L3 or proximal. Patients undergoing an additional surgical procedure had lower health-related quality of life than those who did not. Despite this, there was no difference in health-related quality of life for patients with LIV L4 or distal compared with patients with LIV L3 or proximal. This cohort of patients with AIS treated with PSIF demonstrates normal self-reported health-related quality of life compared with the age-matched general population. These long-term outcomes of PSIF for AIS are encouraging.

Level of evidence:

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.