The relationship between paraspinal muscle degeneration and L5/S1 isthmic spondylolisthesis

English Keywords:Isthmic spondylolisthesis  Paraspinal muscle  Fatty infiltration  Cross-sectional area

English Abstract:

  【Abstract】 Objectives: To investigate the relationship between paraspinal muscle degeneration and isthmic spondylolisthesis in L5/S1. Methods: The clinical data of 108 patients with L5/S1 bilateral isthmic spondylolysis admitted and treated at the Department of Orthopedics, the First Affiliated Hospital of Zhengzhou University from January 1, 2020 to December 31, 2023 were retrospectively analyzed. There were 62 females and 46 males, aged 26-86(52.8±10.4) years. All the patients had complete imaging data, including lateral and dynamic lumbar X-ray, lumbar CT and lumbar MRI. According to the presence or absence of spondylolisthesis and Meyerding grading, the patients were divided into non-spondylolisthesis group(28 cases), grade Ⅰ spondylolisthesis group(46 cases) and grade Ⅱ spondylolisthesis group(34 cases). Vertebral body cross-sectional area(V CSA), erector spinae muscle cross-sectional area(ES CSA), multifidus muscle cross-sectional area(MF CSA), and facet joint angle(FJA) were measured at the inferior vertebral endplate of L5 vertebral body on the axial view of lumbar spine MRI. And the mean FJA(mFJA), relative MF CSA(MF rCSA), relative ES CSA(ES rCSA), fat infiltration rate of multifidus muscle(MF FIR) and fat infiltration rate of erector spinae muscle(ES FIR) were calculated. The differences in age, gender, body mass index(BMI), disease duration, V CSA, mFJA, MF CSA, ES CSA, MF rCSA, ES rCSA, MF FIR and ES FIR between the three groups were compared. Ordinal logistics regression was used to analyze the relationship between age, gender, disease duration, BMI, mFJA, MF rCSA, ES rCSA, MF FIR, ES FIR and the isthmic spondylolisthesis. Results: There were no statistical differences in age, body weight, BMI, V CSA, and mFJA between the three groups(P>0.05). The proportion of female patients in the non-spondylolisthesis group(29%) was significantly lower than that in grade Ⅰ spondylolisthesis group(61%) and grade Ⅱ spondylolisthesis group(76%)(P<0.05). The height of non-spondylolisthesis group(1.68±0.06m) was higher than that of grade Ⅰ spondylolisthesis group(1.64±0.75m) and grade Ⅱ spondylolisthesis group(1.63±0.54m)(P<0.05), and the disease duration in the non-spondylolisthesis group was shorter than that of grade Ⅰ spondylolisthesis group and grade Ⅱ spondylolisthesis group(P<0.05). There was no significant difference in MF CSA, MF rCSA and ES FIR between the three groups(P>0.05). ES CSA and ES rCSA in grade Ⅱ spondylolisthesis group(3183.2±1196.38mm2 and 2.14±1.11) were significantly greater than that in grade Ⅰ spondylolisthesis group(2579.28±896.56mm2 and 1.65±0.65) and non-spondylolisthesis group(2401.40±742.98mm2 and 1.56±0.58)(P<0.05). The MF FIR of grade Ⅱ spondylolisthesis group(40.70±14.05)% was significantly higher than that of grade Ⅰ spondylolisthesis group(30.39±12.98)% and non-spondylolisthesis group(26.69±9.96)%(P<0.05). There were no significant differences in ES CSA, ES rCSA and MF FIR between grade Ⅰ spondylolisthesis group and non-spondylolisthesis group(P>0.05). Ordinal logistics regression analysis showed that female(OR=2.81; 95%CI: 1.120-7.062; P=0.028) and increased MF FIR(OR=1.044; 95%CI: 1.003-1.088; P=0.034) were the independent risk factors for the progression of isthmic spondylolisthesis(P<0.05). Conclusions: Patients with a higher degree of isthmic spondylolisthesis have more severe fat infiltration of multifidus muscle and hypertrophy of erector spinae muscle. Female and increased MF FIR are independent risk factors for the progression of isthmic spondylolisthesis.