Is Lenke type V adolescent idiopathic scoliosis associated with different muscular morphometry?

The aim of the study was to evaluate the changes in psoas major (PM), erector spinae (ES), multifidus (MF), and rectus abdominis (RA) morphometry in Lenke type V adolescent idiopathic scoliosis (AIS) and control. Forty-two Lenke V AIS patients and 30 control were enrolled. The cross-sectional area (CSA) and CSA index (CI) of the PM, ES, MF, and RA at the T9–L5 levels were measured and compared between Lenke type V patients and control. The CI of the RA was significantly higher in the control group than the Lenke V group in multiple levels. On the other hand, there was no significant difference between patients with Lenke V AIS and control regarding the CI of the RA, ES, and PM. There was no significant difference between concave and convex sides of the Lenke V group regarding the CI of the RA, PM, MF, and ES. RA muscle mass is significantly affected in Lenke type 5 AIS regardless of convex or concave sides. This difference may be related to postural differences and back pain development in Lenke type 5 patients. Level of evidence: Level III.