New 3D Classification System Advances Adolescent Idiopathic Scoliosis Care

A new three-dimensional (3D) classification system for Adolescent Idiopathic Scoliosis (AIS) has been introduced, addressing limitations of traditional two-dimensional approaches and marking a significant step forward in how spinal deformity is described, studied, and treated. The SRS–Lenke–Aubin 3D classification, published in Spine Deformity, expands upon the widely used Lenke classification by formally incorporating transverse plane deformity.

Understanding Adolescent Idiopathic Scoliosis

Adolescent Idiopathic Scoliosis (AIS) is a complex spinal deformity that occurs during adolescence. It is characterized by a sideways curvature of the spine, often accompanied by rotation. Traditionally, clinical evaluation has relied heavily on two-dimensional (2D) radiographic parameters, such as the Cobb angle and the Lenke classification. However, scoliosis is fundamentally a three-dimensional condition, and relying solely on 2D measurements can overlook crucial aspects of the deformity.

The SRS-Lenke-Aubin 3D Classification System

The SRS–Lenke–Aubin 3D classification system builds upon the established Lenke classification and introduces two complementary 3D descriptors: the orientation of the regional plane of deformation (ORPD) and the apical vertebral rotation (AVR). These indices capture transverse plane deformities at the regional and local levels, respectively.

The system was developed by the 3D Classification Task Force of the Scoliosis Research Society (SRS) to provide a more comprehensive and clinically relevant characterization of spinal deformities in AIS. It aims to be intuitive, reproducible, and readily applicable by spine surgeons.

Benefits of a 3D Approach

By offering a truly three-dimensional reading of scoliosis, the SRS-Lenke-Aubin classification aims to improve clinical decision-making and adapt treatments to each individual spine. The potential benefits for adolescents include:

• More balanced surgical corrections
• A more harmonious back silhouette
• Improved quality of life

The new classification supports modern surgical planning and serves as a bridge for 2D practice with 3D-informed care.

Research and Validation

The applicability of the classification was evaluated using a cohort of 285 adolescents who underwent surgery for idiopathic scoliosis, with their spines reconstructed in 3D. The results, published in Spine Deformity, confirm that the new 3D descriptors provide complementary and clinically relevant information, enriching the understanding of scoliosis beyond current measures.

Previous research has also evaluated the reliability of 3D classification systems for specific subtypes of AIS, such as Lenke 1 AIS, demonstrating moderate to strong reliability among radiologists and orthopedic surgeons when using only two-view spinal radiographs.

Looking Ahead

The SRS-Lenke-Aubin 3D classification represents a significant advancement in the understanding and treatment of adolescent idiopathic scoliosis. By embracing a three-dimensional perspective, clinicians can strive for more precise diagnoses, personalized treatment plans, and better outcomes for patients.