Treatment recommendations for idiopathic scoliosis: an assessment of the Lenke classification

To determine the usefulness of the treatment recommendation criteria based on the Lenke classification for treatment of idiopathic scoliosis. DESIGN A retrospective radiographic review of 183 patients who underwent anterior and/or posterior fusion for the treatment of idiopathic scoliosis.

Recent studies have proven that the Lenke system is relatively efficient and consistent in classifying scoliosis curves. However, the recommendations regarding fusion level have yet to be established as reliable.

One hundred eighty-three patients with idiopathic scoliosis and with a minimum follow-up period of 24 months were included in the study and classified according to the Lenke system. Among these patients, 135 patients were treated with fusion and instrumentation in accordance with the Lenke classification system and are described as Group I. The 48 patients whose treatments were not based on the Lenke system constitute Group II. These two groups were compared in regard to the correction of the Cobb angle and the trunk shift after surgery in order to establish the effectiveness and reliability of the treatment recommendations based on the Lenke classification system.

Type 1 primary thoracic curve: there was no difference between the results from the group with selective thoracic fusion (Group I) and from the group with both thoracic and lumbar curves fused (Group II). Type 2 double thoracic scoliosis: the correction of the upper thoracic curve, the first thoracic vertebral tilt, and left shoulder elevation were better in the group with both thoracic curves fused (Group I) than in the group with midthoracic fusion (Group II). Type 3 double major scoliosis: the lumbar curve correction was better in the group with both thoracic and lumbar curves fused (Group I) than in the group with selective thoracic fusion (Group II), and decompensation occurred more frequently in Group II. Type 4 triple major scoliosis: because there were only two patients with this type of curve, no analysis was completed. Type 5 thoracolumbar or lumbar curve: there was no difference between the results from the group with selective thoracolumbar or lumbar fusion (Group I) and the group with thoracic and lumbar curves fused (Group II). Type 6 double major scoliosis with larger lumbar curve: the thoracic curve correction was better in the group with both curves fused (Group I) than in the group with only the lumbar curve fused (Group II).

Better radiologic results were achieved through the use of the Lenke classification system for the selection of fusion levels by avoiding unnecessary fusion of the nonstructural lumbar or thoracic spine as well as avoiding undercorrection of the structural secondary curves.