Abstract

Objective
To investigate the association of quantitative paraspinal muscle measurements to the Oswestry disability index (ODI) in patients with lumbar spondylolisthesis.
Materials and Methods
Ninety two patients (mean age, 61.6 years; male, mean age, 71.8 years ; female; mean body mass index [BMI], 24.9 kg/m² ) who had undergone lumbar fusion due to spondylolisthesis with available selfcompleted postoperative ODI were included. The total cross-sectional area (CSA) and functional CSA (FCSA; i.e., area containing only lean muscle tissue) of the paraspinal muscle group (multifidus and erector spinae muscles) and the psoas muscles were measured at L2–L3, L3–L4, and L4–L5 disc levels each on preoperative magnetic resonance imaging (MRI) and the sum of areas at each level served as representative values for each muscle. The FCSA/total CSA ratio and the skeletal muscle index (SMI=muscle area [cm² ]/patient height2 [m² ]) were calculated. Pearson’s correlation analyses were performed to evaluate the relationship between preoperative paraspinal muscle measurements and postoperative ODI.
Results
Quantitative values of low paraspinal muscle showed significant correlation with high ODI values. As a result of this study, the preoperative paraspinal muscle was quantified in the group of patients undergoing spinal fusion. Patients with low value in CSA and FCSA of paraspinal muscle could observe the tendency to transition to low clinical outcomes. Therefore, quantitative values of surrounding muscles are factors affecting clinical outcomes of patients undergoing spinal surgery Conclusion: Smaller muscle bulk (total CSA) of psoas muscles and lean muscle mass (FCSA) of paraspinal muscle group and psoas muscles combined on preoperative MRI were associated with significant postoperative disability based on ODI in patients with lumbar spondylolisthesis.

• Keywords: Paraspinal muscle, Oswestry disability index, Lumbar, Spondylolisthesis