Lack of improvement in health-related quality of life (HRQOL) scores 6 months after surgery for adult spinal deformity (ASD) predicts high revision rate in the second postoperative year.

PURPOSE: ASD is assessed radiologically with the spinopelvic parameters and clinically with HRQOL scores. The revision rate after ASD surgery is high and usually occurs during the first or second postoperative year. The aim of this study is to find clinical or radiological factors that could predict revision surgery in the second postoperative year.

MATERIALS AND METHODS: Inclusion criterion: ASD patients operated on by instrumented posterior fusion with more than 2 years follow-up were enrolled prospectively. Additional criterion was no revision surgery during the first postoperative year. From a multicenter database of 560 operated ASD patients, 164 patients met these criteria. The patients were divided into two groups depending on the need of revision surgery during the second postoperative year. Preoperative, 6-month, 1-year and 2-year data were collected and compared for both groups.

RESULTS: A total of 22 patients needed revision surgery and 142 did not. All revisions were for mechanical complications (non-fusion and implant related). Preoperatively, there was a significant difference between the groups (no revision vs. revision) for age (48 vs. 60 years), ODI (37 vs. 53), and SVA (29 vs. 76 mm), respectively. At 6 months, a significant difference in sagittal alignment was found, though HRQOL scores were similar. At 1 year, the no revision group scores improved, whereas the revision group scores remained stable or worsened. At 2 years, the no revision group scores remained stable. Comparing 6- and 12-month data, patients with improved, stable and worsened HRQOL scores had 8, 15 and 28% revision rates, respectively.

CONCLUSION: The revision rate at the second-year post-surgery (13.4%) remains high and demonstrated that a 2-year follow-up is mandatory. In addition to usual risk factors for mechanical complications in ASD surgery, stabilization or worsening of the HRQOL scores between the 6th and 12th month postop was highly predictive of revision rate. This observation is beneficial for ASD patient follow-up as clinical symptoms clearly precede mechanical failure.