The relationship between paraspinal sarcopenia and adjacent segment refracture after percutaneous kyphoplasty

English Keywords:Adjacent vertebral compression fracture  Sarcopenia  Percutaneous kyphoplasty  Risk factor

English Abstract:

  【Abstract】 Objectives: To investigate the association between paravertebral sarcopenia and adjacent vertebral compression fracture(AVCF) after percutaneous kyphoplasty(PKP) for osteoporotic vertebral compression fracture(OVCF). Methods: Data were retrospectively collected from 272 OVCF patients who had AVCF within 1 year after receiving PKP at our hospital from January 2017 to December 2019. 42 patients who met the inclusion and exclusion criteria were selected as the AVCF group, and the control group was composed of OVCF patients who did not have AVCF within 1 year after PKP only at our hospital during the same period. Each patient in the AVCF group was matched to a strict propensity score based on age, gender, body mass index(BMI), and the first segment of PKP treatment. Preoperative MRI of the lumbar spine was performed in both groups, and the total cross-sectional area(CSA) and functional cross-sectional area(FCSA) of paravertebral muscles(PVM) at L3 and L4[multifidus(MF), erector spinae(ES), psoas(PS)] were measured on MRI. The CSA vertebra index(CSA-VI) and FCSA vertebra index(FCSA-VI) were calculated. The L5 CT values were obtained on the sagittal reconstructed CT images as the preoperative bone mineral density(BMD); the kyphotic angle (KA) and anterior-to-posterior body height ratio(AP ratio) were measured on the radiographs, and the leakage of bone cement into the intervertebral disc was recorded. The t-test, Delong, ROC analysis and multi-factor Logistic regression analysis were used to find independent risk factors for AVCF after PKP. Results: The mean CSA, FCSA, and FCSA-VI of MF, ES, PVM, and PS were smaller in the AVCF group than in the control group at the L3 and L4 levels, with statistically significant differences(P<0.05). The DeLong test showed that the FCSA-VI of ES(0.806 vs 0.900) and PVM(0.861 vs 0.941) at the L4 level in predicting AVCF AUC was greater than that of L3 level, and the difference was statistically significant(P<0.05). ROC analysis showed that FCSA-VI of PVM at L4 level had an AUC of 0.941(P<0.001) with a sensitivity and specificity of 90.5%. Univariate analysis showed that BMD was lower in the AVCF group than in the control group (93.55±14.99HU vs 106.31±10.95HU); the preoperative KA was greater than in the control group(16.02°±17.36° vs 12.87°±6.58°), with a statistically significant difference(P<0.05). Logistic regression analysis showed the decrease in FCSA-VI at the L4 level of PVM(OR 0.830; 95%CI 0.760-0.906) and reduced BMD(OR 0.928; 95%CI 0.891-0.966) were the independent risk facors of AVCF after PKP. Conclusions: Paraspinal sarcopenia at L4 is an independent risk factor for AVCF after PKP in OVCF patients.