Associations of quantitative CT parameters of lumbar paraspinal muscles with fracture severity and postoperative complications in patients with osteoporotic vertebral compression fractures

English Keywords:Osteoporotic vertebral compression fractures  Vertebral compression degree  Complications  Lumbar paraspinal muscles  Quantitative CT parameters  Correlation

English Abstract:

  【Abstract】 Objectives: To investigate the associations between quantitative CT parameters of the lumbar paraspinal muscles, fracture severity, and postoperative complications in patients with osteoporotic vertebral compression fractures(OVCF). Methods: A total of 222 patients with OVCF who underwent percutaneous kyphoplasty(PKP) at our hospital between June 2022 and December 2024 were retrospectively enrolled, including 41 males and 181 females, aged 68-78 years(73.1±2.6 years). According to the Genant semiquantitative grading system, patients were classified into a mild group(n=80, vertebral compression ratio <25%), moderate group(n=82, vertebral compression ratio 25%-40%), and severe group(n=60, vertebral compression ratio >40%). Quantitative CT parameters of the paraspinal muscles and psoas major muscles were measured, including the cross-sectional area of intermuscular adipose tissue(CSAIMAT), intermuscular adipose tissue(IMAT) infiltration, and CT attenuation values. Demographic and clinical characteristics, including age, sex, body mass index(BMI), hypertension, diabetes mellitus, hyperlipidemia, chronic kidney disease, fracture freshness, smoking history, alcohol consumption, preoperative bone mineral density, fracture severity, length of hospital stay, and operative time, were collected. Pearson correlation analysis was performed to evaluate the correlations between quantitative CT parameters and vertebral compression ratio. According to the occurrence of postoperative complications within 6 months after surgery, patients were divided into a complication group(n=62) and a non-complication group(n=160). Univariate analysis was performed to compare baseline characteristics and quantitative CT parameters between the two groups, followed by multivariate logistic regression analysis to identify CT parameters associated with postoperative complications. Receiver operating characteristic(ROC) curves were constructed using the occurrence of postoperative complications as the outcome variables, and CT quantitative indicators of the paraspinal muscle and psoas major muscle as the detection variables to evaluate the predictive ability of each index for the occurrence of postoperative complications. Results: Significant differences were observed in the CSAIMAT, IMAT, and CT attenuation values of the paraspinal muscles and psoas major muscles among patients with different vertebral compression degree groups(P<0.001), whereas no significant differences were found in the remaining quantitative CT parameters(P>0.05). Pairwise comparisons demonstrated that the severe group had significantly higher CSAIMAT and IMAT values and lower CT attenuation values than both the moderate and mild groups(P<0.01). Compared with the mild group, the moderate group exhibited significantly higher CSAIMAT values and lower CT attenuation values(P<0.01). During the 6-month follow-up, postoperative complications occurred in 62 patients, including bone cement leakage(18 cases), recurrence of vertebral fracture(6 cases), infection(12 cases), neurological compression symptoms(19 cases), and perioperative hemoglobin reduction(20 cases). Univariate analysis showed no significant differences between the two groups with respect to age, sex, BMI, hypertension, diabetes mellitus, hyperlipidemia, chronic kidney disease, smoking history, alcohol consumption, fracture freshness, bone mineral density, length of hospital stay, or operative time(P>0.05). However, significant differences were observed in vertebral compression degree, CSAIMAT, IMAT, and CT attenuation values of the paraspinal muscles, as well as CSAIMAT and IMAT of the psoas major muscles(P<0.05). Multivariate logistic regression analysis demonstrated that increased CSAIMAT and IMAT of both the paraspinal muscles and psoas major muscles were associated with an increased risk of postoperative complications, whereas higher CT attenuation values of the paraspinal muscles were associated with a reduced risk of postoperative complications(P<0.05). The logistic regression model incorporating CSAIMAT and IMAT of the paraspinal muscles and psoas major muscles, together with the CT attenuation values of the paraspinal muscles, achieved an area under the ROC curve(AUC) of 0.993[95% confidence interval(CI): 0.959-1.000], with a sensitivity of 95.16% and a specificity of 96.09%. Its predictive performance was significantly superior to that of any individual quantitative CT parameter(DeLong test, P<0.05). Conclusions: Quantitative CT parameters of the paraspinal muscles and psoas major muscles differ significantly among OVCF patients with vertebral compression degrees and are associated with postoperative complications. Quantitative CT parameters, including CSAIMAT, IMAT, and CT attenuation values, may serve as objective imaging biomarkers for assessing the risk of postoperative complications.