Complication Rates Following Adult Spinal Deformity Surgery: Evaluation of the Category of Complication and Chronology.

Overview

abstract

OBJECTIVE: Provide benchmarks for the rates of complications by type and timing. STUDY DESIGN: Prospective multicenter database. BACKGROUND: Complication rates following adult spinal deformity (ASD) surgery have been previously reported. However, the interplay between timing and complication type warrants further analysis. METHODS: The data for this study were sourced from a prospective, multicenter ASD database. Date and type of complication were collected and classified into three severity groups (minor, major, major leading to reoperation). Only complications occurring before the 2-year visit were retained for analysis. RESULTS: Of the 1260 patients eligible for 2-year follow-up, 997 (79.1%) achieved 2-year follow-up. The overall complication rate was 67.4% (N=672). 247 patients (24.8%) experienced at least one complication on the day of surgery (including intra-operatively), 359 (36.0%) between post-op day 1 and 6 weeks post-op, 271 (27.2%) between 6 weeks and 1 one -year post-op, and finally 162 (16.3%) between 1 year and 2 years post-op. Using Kaplan-Meier survival analysis, the rate of remaining complication-free was estimated at different time points for different severities and types of complications. Stratification by type of complication demonstrated that most of the medical complications occurred within the first 60 days. Surgical complications presented over two distinct timeframes. Operative complications, incision-related complications, and infections occurred early (within 60 d), while implant-related and radiographic complications occurred at a constant rate over the 2-year follow-up period. Neurologic complications had the highest occurrence within the first 60 days but continued to increase up to the 2-year visit. CONCLUSION: Only one-third of ASD patients remained complication-free by 2 years, and 2 out of 10 patients had a complication requiring a reoperation or revision. Estimation of timing and type of complication associated with surgical treatment may prove useful for more meaningful patient counseling and aid in assessing the cost-effectiveness of treatment.