Analysis of Correlation Between Degeneration of Lower Lumbar Paraspinal Muscles and Spinopelvic Alignment in Patients with Osteoporotic Vertebral Compression Fracture

Background: A few studies have pointed that trunk extensors may affect the spinopelvic alignment; however, little is known about the exact association between degeneration of lower lumbar paraspinal muscles and spinopelvic parameters.

Objective: The study aimed to analyze the relationship between degeneration of lower lumbar paraspinal muscles and spinopelvic alignment in patients with osteoporotic vertebral compression fracture (OVCF).

Methods: Thirty-nine OVCF patients were involved in this study. All patients underwent a standing lateral radiographs of the entire spine and pelvis 6 months after kyphoplasty. Pelvic incidence, pelvic tilt, lower lumbar lordosis (LLL) were measured. On the MRI images, the cross-sectional areas of the erector spinae (ES), multifidus (MF), vertebral body and the signal intensity of ES, MF, subcutaneous fat were measured. Pearson's correlation coefficients was applied to analyze the correlation between the muscular degeneration degree (muscular atrophy and fatty infiltration) and spinopelvic parameters.

Results: The fatty change degree of ES at L4 inferior endplate level was positively correlated with pelvis retroversion (r= 0.480, p< 0.05). The grade of fat infiltration of ES plus MF at L5 level was negatively related to LLL (r=-0.446, p< 0.05). The fatty change of ES at L5 level, atrophy of ES at L4 and L5 level did not correlate with pelvis back tilt. The fat infiltration of ES plus MF at L4 level, the atrophy degree of ES plus MF at L4 and L5 level had no correlation with LLL.

Conclusions: With the increase of fatty infiltration of the erector spinae, the degree of pelvis retroversion increases; the lower lumbar lordosis decreases with the increase of intramuscular adipose tissue of the erector spinae plus multifidus. The atrophy degree of the erector spinae and multifidus is not correlated with pelvis back tilt and lower lumbar lordosis.