Evaluation of Paravertebral Muscle Structure Asymmetry in Idiopathic Scoliosis Using Imaging Techniques

Objective: This study aimed to assess variances in paravertebral muscle structure in individuals with idiopathic scoliosis (IS) through imaging techniques.

Methods: A cohort of 112 patients diagnosed with IS and treated at our institution between January and December 2023 was included in the analysis. During the same period, 37 patients with secondary scoliosis (SS) were included as controls. Imaging data were used to measure the Cobb angle of the apical vertebrae in scoliosis patients, along with the area and fat infiltration of the paravertebral muscles on both sides. Finally, the cross-sectional area of the paravertebral muscles and the degree of fat infiltration were comparatively evaluated.

Results: In patients with IS, the paravertebral muscles on the concave side of the main curve were significantly larger than those on the convex side (P < 0.05). The concave/convex muscle area ratio in IS patients showed a positive correlation with the Cobb angle and scoliosis duration (both P < 0.05). There was no significant difference in the muscle area ratio between patients with IS and those with SS (P > 0.05). In IS, the paravertebral muscles on the concave side of the main curve exhibited more fat infiltration than those on the convex side, with this fat infiltration positively correlating with body mass index, Cobb angle, age, and scoliosis duration. Similarly, the degree of fat infiltration in the paravertebral muscles on the concave side of SS was more than that observed on the convex side. Furthermore, the degree of fat infiltration in the paravertebral muscles associated with SS was more pronounced compared to that seen in IS (P < 0.05).

Conclusions: In IS patients, the paravertebral muscles on the concave side are more prominent and exhibit more fat infiltration compared to those on the convex side. This fat infiltration positively correlates with the Cobb angle, scoliosis duration, body mass index, and age, possibly indicating scoliosis progression.