Sung Hyun Noh

BACKGROUND AND OBJECTIVE: With the increasing aging population, the number of patients undergoing lumbar spinal surgery for degenerative changes is rising. In the United States, spinal fusion surgery ranked sixth in operating room procedures, accounting for 3.2% of all such procedures, with an aggregate cost for stays amounting to $14.1 billion, making it the most expensive operating room procedure in 2018. The aim of this study was to identify valid risk factors of 90-day unplanned readmissions after lumbar spine surgery through a meta-analysis, with the goal of saving insurance finances and improving patient clinical outcomes. METHODS: We searched PubMed, Embase, Web of Science, and Cochrane Library databases using the search terms “90-day readmission” and “lumbar spine surgery.” Eleven eligible studies were included. Characteristic differences between readmitted and nonreadmitted patients were identified and analyzed using Review Manager software. RESULTS: This meta-analysis included 11 studies with a total of 648 415 patients; 50 047 were readmitted unplanned after lumbar spine surgery. The incidence of unplanned readmission after lumbar spine surgery was 7.72%. Among demographic risk factors, older age and higher body mass index were significantly associated with unplanned readmission after lumbar spine surgery. Patient characteristics, such as depression, diabetes mellitus, hypertension, renal failure, and an American Society of Anesthesiologists grade greater than 2 were also significantly associated with unplanned readmission after lumbar spine surgery. CONCLUSION: The meta-analysis revealed a 7.72% incidence of unplanned readmission after lumbar spine surgery. These findings suggest the need for enhanced preoperative optimization and careful patient selection for lumbar spine surgery, particularly in elderly patients and those with multiple comorbidities. Implementation of targeted preventive strategies for high-risk patients may help reduce unplanned readmissions and improve healthcare resource utilization.

This study measured parameters automatically by marking the point for measuring each parameter on whole-spine radiographs. Between January 2020 and December 2021, 1017 sequential lateral whole-spine radiographs were retrospectively obtained. Of these, 819 and 198 were used for training and testing the performance of the landmark detection model, respectively. To objectively evaluate the program’s performance, 690 whole-spine radiographs from four other institutions were used for external validation. The combined dataset comprised radiographs from 857 female and 850 male patients (average age 42.2 ± 27.3 years; range 20–85 years). The landmark localizer showed the highest accuracy in identifying cervical landmarks (median error 1.5–2.4 mm), followed by lumbosacral landmarks (median error 2.1–3.0 mm). However, thoracic landmarks displayed larger localization errors (median 2.4–4.3 mm), indicating slightly reduced precision compared with the cervical and lumbosacral regions. The agreement between the deep learning model and two experts was good to excellent, with intraclass correlation coefficient values >0.88. The deep learning model also performed well on the external validation set. There were no statistical differences between datasets in all parameters, suggesting that the performance of the artificial intelligence model created was excellent. The proposed automatic alignment analysis system identified anatomical landmarks and positions of the spine with high precision and generated various radiograph imaging parameters that had a good correlation with manual measurements.

Lactoferrin (LF) is a potent antiviral, anti-inflammatory, and antibacterial agent found in cow and human colostrum which acts as an osteogenic growth factor. This study aimed to investigate whether LF-anchored tannylated mesoporous silica nanomaterials (TA-MSN-LF) function as a bone fusion material in a rat model. In this study, we created TA-MSN-LF and measured the effects of low (1 μg) and high (100 μg) TA-MSN-LF concentrations in a spinal fusion animal model. Rats were assigned to four groups in this study: defect, MSN, TA-MSN-LF-low (1 μg/mL), and TA-MSN-LF-high (100 μg/mL). Eight weeks after surgery, a greater amount of radiological fusion was identified in the TA-MSN-LF groups than in the other groups. Hematoxylin and eosin staining showed that new bone fusion was induced in the TA-MSN-LF groups. Additionally, osteocalcin, a marker of bone formation, was detected by immunohistochemistry, and its intensity was induced in the TA-MSN-LF groups. The formation of new vessels was induced in the TA-MSN-LF-high group. We also confirmed an increase in the serum osteocalcin level and the mRNA expression of osteocalcin and osteopontin in the TA-MSN-LF groups. TA-MSN-LF showed effective bone fusion and angiogenesis in rats. We suggest that TA-MSN-LF is a potent material for spinal bone fusion.

The incidence of adult spinal deformity (ASD) increases with age. The current incidence of spinal deformity ranges from 29% in adults aged up to 54 years to more than 65% in adults aged ≥ 65 years. 1 A better understanding of the sagittal alignment of the spine allows for comprehensive surgical planning for ASD. This is the key to achieving optimal surgical alignment and improving results. 2 A recent study of ASD postoperative outcomes reported high complication (8.4%-42%) and mortality (9%-17.6%) rates. 3 The roles of the craniocervical complex (CCC) and upper thoracic spine have rarely been analyzed as mechanical complications of ASD. Cerpa et al. 4 recently suggested that a posterior skull plumbline in front of the instrumented upper spine on postoperative standing radiography may be a risk factor for proximal junctional kyphosis (PJK). Passias et al. 5 reported that age-adjusted alignment goals and distal inclination angle are important parameters for distal junctional kyphosis in cervical deformity surgery. Le Huec et al. 6 reported on the cervical inclination angle (CIA) in 2018, a new angle proposed to analyze the role of CCC in global spinal alignment and PJK risk. CIA was defined as the angle between the center of the dentate process, the midpoint of each thoracic upper endplate, and a horizontal line starting at the center of each thoracic endplate. They analyzed, based on ergonomics, that the thoracic and cervical spine should be aligned and have a small anterior lever arm to maintain sagittal alignment and reduce strain on the spinal muscles. For every 1-cm forward displacement of the line of gravity, a bending moment of +3.5 Nm occurs. This increases the risk of spinal and intervertebral disc injuries. Le Huec et al. 6 reported that the CIA is the angle whose mean value varies little between T1 and T5 (74.9°-76.85°) and gradually increases from T6 to T12. The T1-5 vertebrae always align within each participant's thoracic vertebrae and can be viewed as linear T1-5 segments. The vertical slope of the T1-5 segment is correlated with the C7 slope. They analyzed the normative value of the CIA angle in an adult asymptomatic multiethnic cohort. A total of 468 asymptomatic adult patients were included in this study (176 Caucasian, 119 Japanese, 91 African American, 80 Arab-Berber, and 81 Asian). 7 The mean overall CIA value was 80.12°± 2.8°, while the maximum difference between all thoracic vertebrae was 9° (minimum T5 = 77.05°; maximum T12 = 86.05°). 7 An analysis of the CIA every few decades

Magnetic resonance imaging (MRI) has been extensively used in the management of patients with a herniated lumbar disc. Nevertheless, immediate postoperative MRI has not become a standard procedure, with limited research suggesting that the findings are often similar to preoperative MRI in both symptomatic and asymptomatic patients. This study aimed to determine the benefits of immediate postoperative MRI in patients with or without postoperative symptoms and its correlation with these symptoms. A total of 172 patients who underwent lumbar spine microdiscectomy at our institution between 2014 and 2021 were included. Patients who had previous spinal surgery and lumbar fusion were excluded. Patient data were collected from medical records. MRI was performed 3 days after surgery and assessed by 2 neurosurgeons to minimize bias. Immediate postoperative MRI results showed dural sac compression or foraminal stenosis in 29 patients (16.86%), of which 10 had postoperative pain and 19 were pain free. Among the 143 patients (83.14%) without these findings on MR imaging, 38 had postoperative pain. Immediate postoperative MRI did not correlate with postoperative pain (P = .421/.357). Intraoperative bleeding and the Charlson comorbidity index (CCI) showed significant correlations with postoperative pain (P = .018 and .002, respectively). In a multivariate analysis, intraoperative blood loss and CCI independently correlated with postoperative pain (P = .001 and .001, respectively). Based on our findings, intraoperative blood loss and CCI appear to be the factors that may predict the persistence of postoperative pain, despite normal findings on MRI.

Objective: The aim of study is to investigate the features and risk factors of rod fracture (RF) following adult spinal deformity (ASD) surgery.Methods: We searched the PubMed, Embase, Web of Science, and Cochrane Library databases to identify relevant studies. Patient’s data including age, sex, body mass index (BMI), previous spine surgery, pedicle subtraction osteotomy (PSO), interbody fusion, fusion to the pelvis, smoking history, preoperative sagittal vertical axis (SVA), preoperative pelvic tilt (PT), preoperative pelvic incidence minus lumbar lordosis, preoperative thoracic kyphosis (TK), and change in the SVA were documented. Comparable factors were evaluated using odds ratio (OR) and weighted mean difference (WMD) with 95% confidence interval (CI).Results: Seven studies were included. The overall incidence of RF following ASD surgery was 12%. Advanced age (WMD, 2.8; 95% CI, 1.01–4.59; p < 0.002), higher BMI (WMD, 1.98; 95% CI, 0.65–3.31; p = 0.004), previous spine surgery (OR, 1.47; 95% CI, 1.05–2.04; p = 0.02), PSO (OR, 2.28; 95% CI, 1.62–3.19; p < 0.0001), a larger preoperative PT (WMD, 6.17; 95% CI, 3.55–8.97; p < 0.00001), and a larger preoperative TK (WMD, 5.19; 95% CI, 1.41–8.98; p = 0.007) were identified as risk factors for incidence of RF.Conclusion: The incidence of RF in patients following ASD surgery was 12%. Advanced age, higher BMI, previous spine surgery, and PSO were significantly associated with an increased occurrence of RF. A larger preoperative PT and TK were also identified as risk factors for occurrence of RF following ASD surgery.