Objective: The objective of this study was to evaluate the volume of hidden blood loss (HBL) and analyze its influential factors in single level oblique lateral interbody fusion (OLIF) surgery.Summary of Background Data: OLIF is a minimally invasive spine surgery and is increasingly used to treat lumbar degenerative disk diseases. It is generally believed that there is less bleeding during OLIF. However, HBL during the perioperative period is commonly ignored.Materials and Methods: From January 2018 to December 2019, a total of 70 patients underwent single level OLIF surgery were retrospectively reviewed. The values of preoperative and postoperative hematocrit (Hct) were recorded to reckon HBL in accordance with Gross formula. The influential factors included sex, age, height, weight, body mass index, hypertension, diabetes mellitus, American Society of Anesthesiologists classification, disease etiology, surgery type, operative time, surgical corridor distance, psoas cross-sectional area, thickness of abdominal wall soft tissue, coagulation panel value, platelet count, values of Hct and hemoglobin, and intraoperative blood loss. Independent sample t test, Pearson correlation, Spearman correlation, and multivariate linear regression analysis were performed to investigate the risk factors related to HBL. Results:The average volume of HBL was 809 mL and the average hemoglobin loss was 27.1 g/L in OLIF procedure. Multiple linear regression analysis revealed that thickness of abdominal wall soft tissue was the independent risk factor for HBL (P = 0.008). Whereas age (P = 0.414), activated partial thromboplastin time (P = 0.314), preoperative value of Hct (P = 0.854), disease etiology (P = 0.362), operative time (P = 0.389), and intraoperative blood loss (P = 0.912) were not statistically associated with HBL.Conclusions: HBL was substantial and the average volume of HBL was 809 mL in single level OLIF surgery. The thickness of abdominal wall soft tissue was the risk factor of HBL. Accurate assessment of HBL can prevent perioperative complications and ensure patients' safety.

BACKGROUND: Percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) has been increasingly used to treat degenerative lumbar disease in recent years. However, there are still controversies about whether PE-TLIF is superior to minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). OBJECTIVES: To compare clinical outcomes and complications of PE-TLIF and MIS-TLIF in treating degenerative lumbar disease. STUDY DESIGN: A systematic review and meta-analysis. METHODS: A comprehensive search of online databases including PubMed, Embase, and the Cochrane Library was performed to identify related studies reporting the outcomes and complications of PE-TLIF and MIS-TLIF for degenerative lumbar disease. The clinical outcomes were assessed by the Visual Analog Scale and Oswestry Disability Index. In addition, the operative time, intraoperative blood loss, time to ambulation, length of hospital stay, fusion rate, and surgery-related complications were summarized. Forest plots were constructed to investigate the results. RESULTS: A total of 28 studies involving 1,475 patients were included in this meta-analysis. PE-TLIF significantly reduced operative time, intraoperative blood loss, time to ambulation, and length of hospital stay compared to MIS-TLIF. Moreover, PE-TLIF was superior to MIS-TLIF in the early postoperative relief of back pain. However, there were no significant differences in medium to long-term clinical outcomes, fusion rate, and incidence of complications between PE-TLIF and MIS-TLIF. LIMITATIONS: The current evidence is heterogeneous and most studies included in this meta-analysis are nonrandomized controlled trials. CONCLUSIONS: The present meta-analysis indicates that medium to long-term clinical outcomes and complication rates of PE-TLIF were similar to MIS-TLIF for the treatment of degenerative lumbar disease. However, PE-TLIF shows advantages in less surgical trauma, faster recovery, and early postoperative relief of back pain. KEY WORDS: Percutaneous endoscopic transforaminal lumbar interbody fusion, minimally invasive transforaminal lumbar interbody fusion, degenerative lumbar disease, chronic pain, systematic review, meta-analysis

Aim: To compare the efficacy of 3D printing-assisted surgery with routine surgery in the treatment of distal radius fractures to evaluate whether 3D printing technology has more advantages. Materials & methods: To retrieve all published studies that compared the efficacy of 3D printing-assisted surgery with routine surgery for distal radius fractures. Operation time, frequency of intraoperative fluoroscopy, blood loss and other outcomes were assessed. Results: The results suggested that 3D printing-assisted surgery was better than routine surgery in the fields of operation time, frequency of intraoperative fluoroscopy, and blood loss. Conclusion: In the treatment of distal radius fractures, 3D printing-assisted surgery may be superior to routine surgery.