How to Reduce the Risk of Mechanical Failures in Adult Deformity Surgery: Comparing GAP Score and Roussouly Type...

Area of Science:

• Orthopedics
• Spine Surgery
• Biomechanical Engineering

Background:

• Adult spinal deformity (ASD) surgery aims to correct alignment and reduce pain.
• Mechanical complications are a significant concern, leading to revision surgeries.
• Predicting these complications is crucial for improving patient outcomes.

Purpose of the Study:

• To identify long-term spinal alignment descriptors that correlate with mechanical complications after ASD surgery.
• To evaluate the predictive value of the GAP score and Roussouly type restoration for mechanical failures.
• To analyze the timing and types of mechanical complications.

Main Methods:

• Retrospective cohort study of 212 adult ASD patients with >5-year follow-up.
• Collected demographic, surgical, and radiographic spinopelvic parameters.
• Utilized machine learning and logistic regression to analyze GAP score, Roussouly type, Schwab's criteria, and Odontoid to hip axis angle.
• Kaplan-Meier curves assessed complication rates.

Main Results:

• 40.6% of patients required revision surgery for mechanical complications.
• Higher post-operative GAP scores predicted increased risk of junctional failure (AUC=0.72).
• Failure to restore original Roussouly spinal shape correlated with higher mechanical failure rates. GAP score and Roussouly type were key predictors.

Conclusions:

• Post-operative GAP score and Roussouly type restoration are critical for minimizing mechanical complications.
• Junctional failures tend to occur earlier, while implant failures occur later in the follow-up period.
• Optimizing these alignment parameters can improve long-term outcomes in ASD surgery.