Asymmetric degeneration of paravertebral muscles in degenerative lumbar scoliosis and potential significance / 中华骨科杂志

ABSTRACT

Objective@#To measure the cross-sectional area (CSA) and fatty infiltration (FI) of lumbar paravertebral muscles in patients with degenerative lumbar scoliosis (DLS), and to analyze the mechanism and clinical significance of paravertebral muscles degeneration.@*Methods@#A retrospective study was performed on 118 patients with DLS who were enrolled in our hospital from September 2016 to September 2017. All patients had complete preoperative image data. Preoperative lumbar lordosis (LL), Cobb angle, and vertebral rotation were measured on spinal X-ray plain film. The CSA and FI of the paravertebral muscle on the upper and lower intervertebral level of the scoliosis apical vertebrae were measured by lumbar MRI, and the CSA, FI and their correlation with the Cobb angle were compared.@*Results@#This study enrolled 118 DLS patients, including 49 males and 69 females. The mean age of the patients was 65.4 ± 7.2 years, with an average BMI of 24.7 ± 3.4 and lumbar symptoms including LBP, sciatica, numbness and intermittent claudication, decreased myodynamia and other symptoms. The lasting time of symptoms were 21 months (3-60 months). The Cobb angle of the patients averaged 18.5°±6.7°. Of all patients, 60 patients had a scoliosis to the left, and 58 patients had a scoliosis to the right. The number of patients with lateral apical vertebrae located at L1-L4 were 12 cases of L1, 41 cases of L2, 49 cases of L3, 16 cases of L4. The CSA of the concave side psoas muscle was significantly larger than that of the convex side(upper intervertebral level, concave side 3.74±2.17 cm2, convex side 3.56±1.91 cm2; lower intervertebral level, concave side 6.54±3.08 cm2, convex side 6.31±3.302 cm2. And the CSA of the concave side multifidus muscle and the extensor muscle group was significantly smaller than the convex side, multifidus muscle upper intervertebral level, concave side 9.47±3.86 cm2, convex side 10.25±4.20 cm2; lower intervertebral level, concave side 9.30±3.61 cm2, convex side 10.21±3.81 cm2; extensor muscle group upper intervertebral level, concave side 18.35±4.94 cm2, convex side 19.37±5.17 cm2; lower intervertebral level, concave side 18.98±4.73 cm2, convex side 19.81±5.16 cm2. The concave side FI of extensor muscle group is significantly larger than the convex side, upper intervertebral level, concave side 30.63±15.09, convex side 23.48±15.00; lower intervertebral level, concave side 37.87±19.38, convex side 30.43±16.89. There was a correlation between the degree of asymmetry of CSA and FI in the multifidus, dorsal extension muscles, paravertebral muscle and the scoliosis Cobb angle.@*Conclusion@#The paravertebral muscles of lumbar vertebrae are not a whole in the degenerative changes of DLS. There are different anatomical and physiological effects of lumbar flexion and extension muscle groups. The extensor muscles play an important role in antagonizing the progression of DLS. Improving paravertebral muscle function is an important element in the treatment of DLS.