RESUMEN
【Objective】 To explore the relationship between hidden blood loss （HBL） and risk factors in percutaneous endoscopic interlaminar discectomy （PEID）. 【Methods】 We retrospectively analyzed 113 patients （67 males and 46 females， aged 21-71 years old） with lumbar disc herniation （L5-S1 level） who underwent PEID with complete clinical data in the Department of Spinal Surgery of Subei People’s Hospital Affiliated to Yangzhou University from January 2018 to August 2020. The collected data included general patient indicators （age， body mass index and gender）， underlying diseases （hypertension and diabetes）， laboratory tests （prothrombin time， activated partial thromboplastin time， fibrinogen， hematocrit and hemoglobin level）， imaging related parameters （grade of intervertebral disc degeneration， interlaminar space height and soft tissue thickness of interlaminar approach）， intraoperative significant blood loss and operation time. According to the Gross formula， total blood loss and HBL during operation were calculated. And the risk factors of HBL was analyzed. 【Results】 The total perioperative blood loss was （394.85±130.50） mL， and HBL was （337.09±124.98） mL which accounted for 85.4% of the total blood loss. Multivariate linear regression analysis showed that operation time （P<0.001） and disc degeneration grade （P=0.020） were independent risk factors of HBL. 【Conclusion】 HBL is the main cause of blood loss during PEID， and operation time and disc degeneration grade are independent risk factors that affect the amount of HBL.
RESUMEN
Objective:To establish a scoring system based on lumbar magnetic resonance imaging (MRI) images to evaluate bone mineral density and evaluate its correlation with T score of dual energy X-ray absorptiometry (DEXA).Methods:The clinical data of 82 patients with lumbar degenerative diseases who were admitted to the Clinical Medical College of Yangzhou University from January 2019 to August 2020 were analyzed retrospectively. According to the lower value of T value of femoral neck and total hip bone mineral density detected by DEXA, they were divided into normal bone mass group ( n=40) and abnormal bone mass group ( n=42). The vertebral body bone mass (VBQ) score of the patient was calculated by dividing the average signal intensity of L 1-4 vertebral body by the signal intensity of L 3 level cerebrospinal fluid on T 1 weighted image of MRI. The receiver operating characteristic (ROC) curve was drawn to evaluate the ability of VBQ score to distinguish between normal bone mass and abnormal bone mass and the accuracy of predicting the occurrence of abnormal bone mass. Further, the correlation between VBQ score and T value was determined by regression analysis. Results:The lowest T value measured by DEXA in the abnormal bone mass group were significantly lower than those in the normal bone mass group, and the VBQ score was significantly higher than that in the normal bone mass group(all P<0.001). The area under curve (AUC) of VBQ score for predicting abnormal bone mass was 0.93, the cut-off value was 2.98, with sensitivity 81.6%, and specificity 88.6%. The VBQ score was corrected with the lowest T value measured by DEXA ( r=-0.77). Conclusions:VBQ score could effectively distinguish normal bone mass from abnormal bone mass and was negatively correlated with the lowest T value of DEXA.