Risk factors affecting spinal fusion: A meta-analysis of 39 cohort studies.

PURPOSE: We performed a meta-analysis to identify risk factors affecting spinal fusion. METHODS: We systematically searched PubMed, Embase, and the Cochrane Library from inception to January 6, 2023, for articles that report risk factors affecting spinal fusion. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed-effects models for each factor for which the interstudy heterogeneity I2 was < 50%, while random-effects models were used when the interstudy heterogeneity I2 was ≥ 50%. Using sample size, Egger's P value, and heterogeneity across studies as criteria, we categorized the quality of evidence from observational studies as high-quality (Class I), moderate-quality (Class II or III), or low-quality (Class IV). Furthermore, the trim-and-fill procedure and leave-one-out protocol were conducted to investigate potential sources of heterogeneity and verify result stability. RESULTS: Of the 1,257 citations screened, 39 unique cohort studies comprising 7,145 patients were included in the data synthesis. High-quality (Class I) evidence showed that patients with a smoking habit (OR, 1.57; 95% CI, 1.11 to 2.21) and without the use of bone morphogenetic protein-2 (BMP-2) (OR, 4.42; 95% CI, 3.33 to 5.86) were at higher risk for fusion failure. Moderate-quality (Class II or III) evidence showed that fusion failure was significantly associated with vitamin D deficiency (OR, 2.46; 95% CI, 1.24 to 4.90), diabetes (OR, 3.42; 95% CI, 1.59 to 7.36), allograft (OR, 1.82; 95% CI, 1.11 to 2.96), conventional pedicle screw (CPS) fixation (OR, 4.77; 95% CI, 2.23 to 10.20) and posterolateral fusion (OR, 3.63; 95% CI, 1.25 to 10.49). CONCLUSIONS: Conspicuous risk factors affecting spinal fusion include three patient-related risk factors (smoking, vitamin D deficiency, and diabetes) and four surgery-related risk factors (without the use of BMP-2, allograft, CPS fixation, and posterolateral fusion). These findings may help clinicians strengthen awareness for early intervention in patients at high risk of developing fusion failure.

Analysis of Risk Factors for Urinary Tract Infection after Lumbar Interbody Fusion.

OBJECTIVE: Urinary tract infection (UTI) is a common postoperative complication, so exploring its risk factors is helpful to provide a basis for clinical prevention. This study aims to analyse the risk factors for UTI after lumbar interbody fusion (LIF). METHODS: A single-centre retrospective study was conducted on the clinical data of 358 patients treated with LIF from April 2020 to April 2023. In accordance with the results of postoperative urine culture, the patients were divided into UTI group (n = 19, those with UTI after LIF) and control group (n = 332, those without UTI after LIF). Binary logistic regression analysis was carried out through collecting the medical records of the two groups to probe into the risk factors for UTI after LIF. RESULTS: After seven patients were excluded, the remaining 351 patients were included in the analysis. In this study, 19 patients (5.41%) developed postoperative UTI, whereas 332 patients (94.59%) had no UTI. Regression analysis results showed drinking (odds ratio (OR) = 16.193, 95% confidence interval (CI): 1.017-257.860) and high preoperative C-reactive protein (CRP) level (OR = 3.237, 95% CI: 1.213-8.636) as risk factors for UTI after LIF. A high professional title of main surgeon (OR = 0.095, 95% CI: 0.010-0.932) and preoperative red blood cell (RBC) count (OR = 0.001, 95% CI: 0.000-0.198) were protective factors for UTI after LIF (p < 0.05). CONCLUSIONS: This study advocated strengthening the prevention and treatment of UTI in patients who had drinking history, high preoperative CRP level and low preoperative RBC count, and received LIF based on the study results. Attention should be paid to the training of physicians with low professional title.

Can zoledronic acid reduce the risk of cage subsidence after oblique lumbar interbody fusion combined with bilateral pedicle screw fixation in the elderly population? A retrospective study.

BACKGROUND: The objective of this study was to evaluate the potential of zoledronic acid for reducing the incidence of cage subsidence and enhancing interbody fusion rates following oblique lumbar interbody fusion (OLIF) surgery, particularly as the first reported evidence of the role of zoledronic acid combined with OLIF. METHODS: A retrospective analysis was conducted on data from 108 elderly patients treated for degenerative lumbar diseases using OLIF combined with bilateral pedicle screw fixation from January 2018 to December 2021. Patients were divided into the zoledronic acid (ZOL) group (43 patients, 67 surgical segments) and the control group (65 patients, 86 surgical segments). A comparative analysis of the radiographic and clinical outcomes between the groups was performed, employing univariate and multivariate regression analyses to explore the relationships between cage subsidence and the independent variables. RESULTS: Radiographic outcomes, including anterior height, posterior height, disc height, coronal disc angle, foraminal height, and lumbar lordosis, were not significantly different between the two groups. Similarly, no statistically significant differences were noted in the back visual analog scale (VAS) scores and Oswestry Disability Index (ODI) scores between the groups. However, at the 1-year follow-up, the leg VAS score was lower in the ZOL group than in the control group (P = 0.028). The ZOL group demonstrated a notably lower cage subsidence rate (20.9%) than did the control group (43.0%) (P < 0.001). There was no significant difference in the interbody fusion rate between the ZOL group (93.0%) and the control group (90.8%). Non-use of zoledronic acid emerged as an independent risk factor for cage subsidence (OR = 6.047, P = 0.003), along with lower bone mineral density, lower postoperative anterior height, and concave endplate morphology. The model exhibited robust discriminative performance, with an area under the curve (AUC) of 0.872. CONCLUSION: The administration of zoledronic acid mitigates the risk of cage subsidence following OLIF combined with bilateral pedicle screw fixation in elderly patients; however, it does not improve the interbody fusion rate.

Survey of major complications after prone transpsoas surgery: an analysis of early adopters' practice.

INTRODUCTION: The prone transpsoas technique (PTP) is a modification of the traditional lateral lumbar interbody fusion approach, which was first published in the literature in 2020. The technique provides several advantages, such as lordosis correction and redistribution, single-position surgery framework, and ease of performing posterior techniques when needed. However, the prone position also leads to the movement of some retroperitoneal, vascular, and neurological structures, which could impact the complication profile. Therefore, this study aimed to investigate the occurrence of major complications in the practice of early adopters of the PTP approach. METHODS: A questionnaire containing 8 questions was sent to 50 participants and events involving early adopters of the prone transpsoas technique. Of the 50 surgeons, 32 completed the questionnaire, which totaled 1963 cases of PTP surgeries. RESULTS: Nine of the 32 surgeons experienced a major complication (28%), with persistent neurological deficit being the most frequent (7/9). Of the total number of cases, the occurrence of permanent neurological deficits was approximately 0,6%, and the rate of vascular and visceral injuries were both 0,05% (1/1963 for each case). CONCLUSION: Based on the analysis of the questionnaire responses, it can be concluded that PTP is a safe technique with a very low rate of serious complications. However, future studies with a more heterogeneous group of surgeons and a more rigorous linkage between answers and patient data are needed to support the findings of this study.

The efficacy and safety of decompression with interspinous fixation for lumbar spondylolisthesis when compared with posterior lumbar interbody fusion: A pilot study.

Posterior lumbar interbody fusion (PLIF) is widely used to treat degenerative spondylolisthesis because it provides definitive decompression and fixation. Although it has several advantages, it has some disadvantages and risks, such as paraspinal muscle injury, potential intraoperative bleeding, postoperative pain, hardware failure, subsidence, and medical comorbidity. Lumbar decompressive bilateral laminectomy with interspinous fixation (DLISF) is less invasive and can be used on some patients with PLIF, but this has not been reported. To compare the efficacy and safety of DLISF in the treatment of low-grade lumbar spondylolisthesis with that of PLIF. We retrospectively analyzed the medical records of 81 patients with grade I spondylolisthesis, who had undergone PLIF or DLISF and were followed up for more than 1 year. Surgical outcomes, visual analog scale, radiologic outcomes, including Cobb angle and difference in body translation, and postoperative complications were assessed. Forty-one patients underwent PLIF, whereas 40 underwent DLISF. The operative times were 271.0 ±â€…57.2 and 150.6 ±â€…29.3 minutes for the PLIF and DLISF groups, respectively. The estimated blood loss was significantly higher in the PLIF group versus the DLISF group (290.7 ±â€…232.6 vs 122.2 ±â€…82.7 mL, P < .001). Body translation did not differ significantly between the 2 groups. Overall pain improved during the 1-year follow-up when compared with baseline data. Medical complications were significantly lower in the DLISF group, whereas perioperative complications and hardware issues were higher in the PLIF group. The outcomes of DLISF, which is less invasive, were comparable to PLIF outcomes in patients with low-grade spondylolisthesis. As a salvage technique, DLISF may be a good option when compared with PLIF.

The hemostatic and anti-inflammatory effects of intravenous single-dose of tranexamic acid in double-segment posterior lumbar interbody fusion: a case control study.

This study aims to observe the hemostatic and anti-inflammatory effects of intravenous administration of tranexamic acid (TXA) in dual segment posterior lumbar interbody fusion (PLIF). The data of 53 patients with lumbar disease treated with double-segment PLIF were included in this study. The observation group was received a single-dose intravenous of TXA (1 g/100 mL) 15 min before skin incision after general anesthesia. The control group was not received TXA. The observation indicators included postoperative activated partial prothrombin time (APTT), thrombin time (PT), thrombin time (TT), fibrinogen (FIB), platelets (PLT), and postoperative deep vein thrombosis in the lower limbs, surgical time, intraoperative bleeding volume, postoperative drainage volume, transfusion rate, postoperative hospital stay, red blood cell (RBC), hemoglobin (HB), hematocrit (HCT), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) on the 1st, 4th, 7th, and last tested day after surgery. All patients successfully completed the operation, and there was no deep vein thrombosis after operation. There was no statistically significant difference in postoperative APTT, PT, TT, FIB, PLT, surgical time, and postoperative hospital stay between the two groups (p > 0.05). The intraoperative bleeding volume, postoperative drainage volume, and transfusion rate in the observation group were lower than those in the control group, and the differences were statistically significant (p < 0.05). There was no statistically significant difference in RBC, HB, HCT, CRP, and ESR between the two groups on the 1st, 4th, 7th, and last tested day after surgery (p > 0.05). Intravenous administration of TXA in dual segment PLIF does not affect coagulation function and can reduce bleeding volume, postoperative drainage volume, and transfusion rate. Moreover, it does not affect the postoperative inflammatory response.

Pseudarthrosis risk factors in lumbar fusion: a systematic review and meta-analysis.

This study presents a systematic literature review and meta-analysis of pseudarthrosis risk factors following lumbar fusion procedures. The odds ratio (OR) and 95% confidence interval (95% CI) were used for outcome measurements. The objective of this study was to identify the independent risk factors for pseudarthrosis after lumbar spinal fusion, which is crucial for mitigating morbidity and reoperation. Systematic searches in PubMed, Embase, and Scopus (1990-July 2021) were conducted using specific terms. The inclusion criteria included prospective and retrospective cohorts and case‒control series reporting ORs with 95% CIs from multivariate analysis. The quality assessment utilized the Newcastle-Ottawa scale. Meta-analysis, employing OR and 95% CI, assessed pseudarthrosis risk factors in lumbar fusion surgery, depicted in a forest plot. Of the 568 abstracts identified, 12 met the inclusion criteria (9 retrospective, 2006-2021). The 17 risk factors were categorized into clinical, radiographic, surgical, and bone turnover marker factors. The meta-analysis highlighted two significant clinical risk factors: age (95% CI 1.02-1.11; p = 0.005) and smoking (95% CI 1.68-5.44; p = 0.0002). The sole significant surgical risk factor was the number of fused levels (pooled OR 1.35; 95% CI 1.17-1.55; p < 0.0001). This study identified 17 risk factors for pseudarthrosis after lumbar fusion surgery, emphasizing age, smoking status, and the number of fusion levels. Prospective studies are warranted to explore additional risk factors and assess the impact of surgery and graft type.

Unilateral biportal endoscopic versus microscopic transforaminal lumbar interbody fusion for lumbar degenerative disease: a retrospective study.

BACKGROUND: In the past decade, Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) with a microscopic tubular technique has become a surgical procedure that reduces surgical-related morbidity, shortens hospital stays, and expedites early rehabilitation in the treatment of lumbar degenerative diseases (LDD). Unilateral biportal endoscopic transforaminal lumbar interbody fusion (Endo-TLIF) has emerged as a novel surgical technique. The present study aims to compare the clinical outcomes and postoperative complications of MIS-TLIF and Endo-TLIF for treating LDD. METHODS: A retrospective analysis of LLD patients undergoing either Endo-TLIF or MIS-TLIF was performed. Patient demographics, operative data (operation time, estimated blood loss, length of hospitalization), and complications were recorded. The visual analog scale (VAS) score for leg and back pain and the Oswestry Disability Index (ODI) score were used to evaluate the clinical outcomes. RESULTS: This study involved 80 patients, 56 in the MIS-TLIF group and 34 in the Endo-TLIF group. The Endo-TLIF group showed a more substantial improvement in the VAS for back pain at 3 weeks post-surgery compared to the MIS-TLIF group. However, at the 1-year mark after surgery, there were no significant differences between the groups in the mean VAS for back pain and VAS for leg pain. Interestingly, the ODI at one year demonstrated a significant improvement in the Endo-TLIF group compared to the MIS-TLIF group. Additionally, the MIS-TLIF group exhibited a shorter operative time than the Endo-TLIF group, with no notable differences in estimated blood loss, length of hospitalization, and complications between the two groups. CONCLUSION: Endo-TLIF and MIS-TLIF are both safe and effective for LDD. In surgical decision-making, clinicians may consider nuances revealed in this study, such as lower early postoperative back pain with Endo-TLIF and shorter operative time with MIS-TLIF.

In idiopathic scoliosis distances of spinal cord to thoracic pedicle are within 2 mm in a large region of the thoracic apex.

Despite a 15% misplacement rate of screws in idiopathic scoliosis surgery, little is known about the relationship between pedicles and nerve structures in the entire thoracic curve. This study aimed to explore the spinal cord's proximity to the pedicle wall at each thoracic vertebra in the entire thoracic curve, while considering different anatomical changes. Spinal cord to medial pedicle distances were measured on magnetic resonance imaging in 73 patients who underwent posterior spinal fusion with pedicle screw instrumentation. Associations with different variables were examined. A total of 51 patients (69.9%) showed a distance within 2 mm at the apex vertebra on the concave side, more than 50% had a distance within 2 mm in the next thoracic vertebra level above and below, and more than 25% two levels above and below. Weak correlations were found between proximity of the spinal cord at the apex vertebra and vertebra's level and Cobb angle on the concave side (r = - 0.310, P = 0.008, r = 0.380, P = 0.001, respectively). These results emphasize the importance of thorough assessment when placing thoracic pedicle screws in idiopathic scoliosis patients. Further research is warranted to develop surgical strategies aimed at preventing potentially neurological complications resulting from screw misplacement.

Pedicle screw insertion into infected vertebrae reduces operative time and range of fixation in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis: a multicenter retrospective cohort study.

BACKGROUND: Minimally invasive posterior fixation surgery for pyogenic spondylitis is known to reduce invasiveness and complication rates; however, the outcomes of concomitant insertion of pedicle screws (PS) into the infected vertebrae via the posterior approach are undetermined. This study aimed to assess the safety and efficacy of PS insertion into infected vertebrae in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis. METHODS: This multicenter retrospective cohort study included 70 patients undergoing minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis across nine institutions. Patients were categorized into insertion and skip groups based on PS insertion into infected vertebrae, and surgical data and postoperative outcomes, particularly unplanned reoperations due to complications, were compared. RESULTS: The mean age of the 70 patients was 72.8 years. The insertion group (n = 36) had shorter operative times (146 versus 195 min, p = 0.032) and a reduced range of fixation (5.4 versus 6.9 vertebrae, p = 0.0009) compared to the skip group (n = 34). Unplanned reoperations occurred in 24% (n = 17) due to surgical site infections (SSI) or implant failure; the incidence was comparable between the groups. Poor infection control necessitating additional anterior surgery was reported in four patients in the skip group. CONCLUSIONS: PS insertion into infected vertebrae during minimally invasive posterior fixation reduces the operative time and range of fixation without increasing the occurrence of unplanned reoperations due to SSI or implant failure. Judicious PS insertion in patients with minimal bone destruction in thoracolumbar pyogenic spondylitis can minimize surgical invasiveness.

Preoperative motor weakness and the impact on patient reported outcomes in lateral lumbar interbody fusion.

This study measures the impact of preoperative motor weakness (MW) on Patient-Reported Outcome Measures (PROMs) in lateral lumbar interbody fusion (LLIF) patients. Retrospectively-sourced data from a prospectively-maintained, single-surgeon database created two cohorts of LLIF patients: patients with/without documented MW. Demographics/perioperative characteristics/PROMs were collected preoperatively and at six-weeks/final follow-up (FF). Studied outcomes were Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), 12-Item Short Form (SF-12) Physical/Mental Component Score (PCS/MCS), Patient Health Questionnaire (PHQ-9), Visual Analog Scale Back/Leg Pain (VAS-BP/LP), and Oswestry Disability Index (ODI). Multivariable linear/logistic regression calculated/compared intercohort minimum clinically important difference (MCID). Mean postoperative follow-up time was 11.5 ± 7.52 months. In total, 214 LLIF patients from December 2010 to May 2023 were included, with 149 having documented MW. In Table 1, self-reported gender was significant between cohorts (p < 0.025). Other significant demographic characteristics were smoker status (p < 0.002), diabetes (p < 0.016), and CCI score (p < 0.011). Table 2 shows notably significant perioperative characteristics: spinal pathology (degenerative spondylolisthesis/foraminal stenosis/herniated nucleus pulposus) (p < 0.005, all), estimated blood loss/length of stay/postoperative day (POD)-zero narcotic consumption (p < 0.001, all). Table 3 outcomes/MCID achievement percentages demonstrated insignificant intercohort differences besides a weakly significant FF ODI score (p < 0.036). MW, a frequently reported symptom in spine surgery, is poorly studied in LLIF patients. Thus, this study evaluates MW impact on PROMs and notes no significant differences. However, one exception regarding FF disability scores was recorded. MW did not affect MCID achievement for our patient population. Therefore, the preliminary findings suggest preoperative MW imparts minimal influence on PROMs/MCID in LLIF patients.

Comparative Analysis of Postoperative Sagittal Balance in Expansive Open-Door Laminoplasty versus Laminectomy with Fusion for Multilevel Ossification of Posterior Longitudinal Ligament: A Retrospective Study.

BACKGROUND This single-center study included 80 patients with multilevel cervical ossification of the posterior longitudinal ligament (OPLL) and aimed to compare postoperative sagittal balance following treatment with expansive open-door laminoplasty (LP) vs total laminectomy with fusion (LF). MATERIAL AND METHODS Data of 80 patients with multilevel OPLL treated with LP vs LF between January 2017 and January 2022 were retrospectively analyzed. The basic data, cervical sagittal parameters, and clinical outcomes of the patients were counted in the preoperative and postoperative periods, and complications were recorded. Forty patients underwent LP and 40 underwent LF. Cervical sagittal parameters were compared between and within the 2 groups. Clinical outcomes and complications were compared between the 2 groups. RESULTS At last follow-up, the postoperative C2-C7 Cobb angel, T1 slope (T1S), and C7 slope (C7S) were significantly higher in the LF group than in the LP group (P<0.001). C2-C7 SVA (cSVA) was slightly higher in the LF group (P>0.05) and significantly higher in the LP group (P<0.05). The incidence of postoperative complications in the LP group was significantly lower than in the LF group (P=0.02). The postoperative scores on the Visual Analog Scale (VAS), Neck Disability Index (NDI), and Japanese Orthopedic Association (JOA) were significantly improved in both groups (P<0.001). CONCLUSIONS Both procedures had good outcomes in neurological improvement. After posterior surgery, the cervical vertebrae all showed a tilting forward. Compared to LP, LF may change cervical balance in Cobb angel, T1S. LF has better efficacy in improving cervical lordosis compared with LP. Patients with high T1 slope after surgery may has more axial pain.

How does cervical sagittal profile change after the spontaneous compensation of global sagittal imbalance following one- or two-level lumbar fusion.

PURPOSE: This study aimed to evaluate the cervical sagittal profile after the spontaneous compensation of global sagittal imbalance and analyze the associations between the changes in cervical sagittal alignment and spinopelvic parameters. METHODS: In this retrospective radiographic study, we analyzed 90 patients with degenerative lumbar stenosis (DLS) and sagittal imbalance who underwent short lumbar fusion (imbalance group). We used 60 patients with DLS and sagittal balance as the control group (balance group). Patients in the imbalance group were also divided into two groups according to the preoperative PI: low PI group (≤ 50°), high PI group (PI > 50°). We measured the spinal sagittal alignment parameters on the long-cassette standing lateral radiographs of the whole spine. We compared the changes of spinal sagittal parameters between pre-operation and post-operation. We observed the relationships between the changes in cervical profile and spinopelvic parameters. RESULTS: Sagittal vertical axis (SVA) occurred spontaneous compensation (p = 0.000) and significant changes were observed in cervical lordosis (CL) (p = 0.000) and cervical sagittal vertical axis (cSVA) (p = 0.023) after surgery in the imbalance group. However, there were no significant differences in the radiographic parameters from pre-operation to post-operation in the balance group. The variations in CL were correlated with the variations in SVA (R = 0.307, p = 0.041). The variations in cSVA were correlated with the variations in SVA (R=-0.470, p = 0.001). CONCLUSION: Cervical sagittal profile would have compensatory changes after short lumbar fusion. The spontaneous decrease in CL would occur in patients with DLS after the spontaneous compensation of global sagittal imbalance following one- or two-level lumbar fusion. The changes of cervical sagittal profile were related to the extent of the spontaneous compensation of SVA.

Relationship between intervertebral disc height and post operative dysphagia secondary to single-level anterior cervical discectomy and fusion- a retrospective study.

BACKGROUND: One goal of Anterior Cervical Discectomy and Fusion (ACDF) is to restore the loss of intervertebral disc height (IDH) results from the degenerative process. However, the effects of IDH on postoperative dysphagia after ACDF remain unclear. METHODS: Based on the results of a one-year telephone follow-up, A total of 217 consecutive patients after single-level ACDF were enrolled. They were divided into dysphagia and non-dysphagia groups. The age, BMI, operation time and blood loss of all patients were collected from the medical record system and compared between patients with and without dysphagia. Radiologically, IDH, spinous process distance (SP) of the operated segment, and C2-7 angle (C2-7 A) were measured preoperatively and postoperatively. The relationship between changes in these radiological parameters and the development of dysphagia was analyzed. RESULTS: Sixty-three (29%) cases exhibited postoperative dysphagia. The mean changes in IDH, SP, and C2-7 A were 2.84 mm, -1.54 mm, and 4.82 degrees, respectively. Changes in IDH (P = 0.001) and changes in C2-7 A (P = 0.000) showed significant differences between dysphagia and non-dysphagia patients. Increased IDH and increased C2-7 A (P = 0.037 and 0.003, respectively) significantly and independently influenced the incidence of postoperative dysphagia. When the change in IDH was ≥ 3 mm, the chance of developing postoperative dysphagia for this patient was significantly greater. No significant relationship was observed between the change in spinous process distance (SP) and the incidence of dysphagia. The age, BMI, operation time and blood loss did not significantly influence the incidence of postoperative dysphagia. CONCLUSION: The change in IDH could be regarded as a predictive factor for postoperative dysphagia after single-level ACDF.

Comparison of minimally invasive transforaminal lumbar interbody fusion and midline lumbar interbody fusion in patients with spondylolisthesis.

BACKGROUND: This study aimed to compare surgical outcomes, clinical outcomes, and complications between minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) and midline lumbar interbody fusion (MIDLIF) in patients with spondylolisthesis. METHODS: This study retrospectively compared the patients who underwent MIS TLIF (n = 37) or MIDLIF (n = 50) for spinal spondylolisthesis. Data of surgical outcomes (postoperative one-year fusion rate and time to bony fusion), clinical outcomes (visual analog scale [VAS] for pain and Oswestry Disability Index [ODI] for spine function), and complications were collected and analyzed. RESULTS: There was more 2-level fusion in MIDLIF (46% vs. 24.3%, p = 0.038). The MIS TLIF and MIDLIF groups had similar one-year fusion rate and time to fusion. The MIDLIF group had significantly lower VAS at postoperative 3-months (2.2 vs. 3.1, p = 0.002) and postoperative 1-year (1.1 vs. 2.1, p = < 0.001). ODI was not significantly different. The operation time was shorter in MIDLIF (166.1 min vs. 196.2 min, p = 0.014). The facet joint violation is higher in MIS TLIF (21.6% vs. 2%, p = 0.009). The other complications were not significantly different including rate of implant removal, revision, and adjacent segment disease. CONCLUSION: In this study, postoperative VAS, operation time, and the rate of facet joint violation were significantly higher in the MIS TLIF group. Comparable outcomes were observed between MIDLIF and MIS TLIF in terms of fusion rate, time to fusion, and postoperative ODI score.

Machine learning models on a web application to predict short-term postoperative outcomes following anterior cervical discectomy and fusion.

BACKGROUND: The frequency of anterior cervical discectomy and fusion (ACDF) has increased up to 400% since 2011, underscoring the need to preoperatively anticipate adverse postoperative outcomes given the procedure's expanding use. Our study aims to accomplish two goals: firstly, to develop a suite of explainable machine learning (ML) models capable of predicting adverse postoperative outcomes following ACDF surgery, and secondly, to embed these models in a user-friendly web application, demonstrating their potential utility. METHODS: We utilized data from the National Surgical Quality Improvement Program database to identify patients who underwent ACDF surgery. The outcomes of interest were four short-term postoperative adverse outcomes: prolonged length of stay (LOS), non-home discharges, 30-day readmissions, and major complications. We utilized five ML algorithms - TabPFN, TabNET, XGBoost, LightGBM, and Random Forest - coupled with the Optuna optimization library for hyperparameter tuning. To bolster the interpretability of our models, we employed SHapley Additive exPlanations (SHAP) for evaluating predictor variables' relative importance and used partial dependence plots to illustrate the impact of individual variables on the predictions generated by our top-performing models. We visualized model performance using receiver operating characteristic (ROC) curves and precision-recall curves (PRC). Quantitative metrics calculated were the area under the ROC curve (AUROC), balanced accuracy, weighted area under the PRC (AUPRC), weighted precision, and weighted recall. Models with the highest AUROC values were selected for inclusion in a web application. RESULTS: The analysis included 57,760 patients for prolonged LOS [11.1% with prolonged LOS], 57,780 for non-home discharges [3.3% non-home discharges], 57,790 for 30-day readmissions [2.9% readmitted], and 57,800 for major complications [1.4% with major complications]. The top-performing models, which were the ones built with the Random Forest algorithm, yielded mean AUROCs of 0.776, 0.846, 0.775, and 0.747 for predicting prolonged LOS, non-home discharges, readmissions, and complications, respectively. CONCLUSIONS: Our study employs advanced ML methodologies to enhance the prediction of adverse postoperative outcomes following ACDF. We designed an accessible web application to integrate these models into clinical practice. Our findings affirm that ML tools serve as vital supplements in risk stratification, facilitating the prediction of diverse outcomes and enhancing patient counseling for ACDF.

Impact of surgical risk factors for non-union on lumbar spinal fusion outcomes using cellular bone allograft at 24-months follow-up.

BACKGROUND: The current report investigates fusion rates and patient-reported outcomes following lumbar spinal surgery using cellular bone allograft (CBA) in patients with risk factors for non-union. METHODS: A prospective, open label study was conducted in subjects undergoing lumbar spinal fusion with CBA (NCT02969616) to assess fusion success rates and patient-reported outcomes in subjects with risk factors for non-union. Subjects were categorized into low-risk (≤ 1 risk factors) and high-risk (> 1 risk factors) groups. Radiographic fusion status was evaluated by an independent review of dynamic radiographs and CT scans. Patient-reported outcome measures included quality of life (EQ-5D), Oswestry Disability Index (ODI) and Visual Analog Scales (VAS) for back and leg pain. Adverse event reporting was conducted throughout 24-months of follow-up. RESULTS: A total of 274 subjects were enrolled: 140 subjects (51.1%) were categorized into the high-risk group (> 1 risk factor) and 134 subjects (48.9%) into the low-risk group (≤ 1 risk factors). The overall mean age at screening was 58.8 years (SD 12.5) with a higher distribution of females (63.1%) than males (36.9%). No statistical difference in fusion rates were observed between the low-risk (90.0%) and high-risk (93.9%) groups (p > 0.05). A statistically significant improvement in patient-reported outcomes (EQ-5D, ODI and VAS) was observed at all time points (p < 0.05) in both low and high-risk groups. The low-risk group showed enhanced improvement at multiple timepoints in EQ-5D, ODI, VAS-Back pain and VAS-Leg pain scores compared to the high-risk group (p < 0.05). The number of AEs were similar among risk groups. CONCLUSIONS: This study demonstrates high fusion rates following lumbar spinal surgery using CBA, regardless of associated risk factors. Patient reported outcomes and fusion rates were not adversely affected by risk factor profiles. TRIAL REGISTRATION: NCT02969616 (21/11/2016).

Preoperative and follow-up variations of psoas major muscle are related to S1 screw loosening in patients with degenerative lumbar spinal stenosis.

BACKGROUND: It was reported the paraspinal muscle played an important role in spinal stability. The preoperative paraspinal muscle was related to S1 screw loosening. But the relationship between preoperative and postoperative change of psoas major muscle (PS) and S1 pedicle screw loosening in degenerative lumbar spinal stenosis (DLSS) patients has not been reported. This study investigated the effects of preoperative and follow-up variations in the psoas major muscle (PS) on the first sacral vertebra (S1) screw loosening in patients with DLSS. METHODS: 212 patients with DLSS who underwent lumbar surgery were included. The patients were divided into the S1 screw loosening group and the S1 screw non-loosening group. Muscle parameters were measured preoperatively and at last follow-up magnetic resonance imaging. A logistic regression analysis was performed to investigate the risk factors for S1 screw loosening. RESULTS: The S1 screw loosening rate was 36.32% (77/212). The relative total cross-sectional areas and relative functional cross-sectional areas (rfCSAs) of the PS at L2-S1 were significantly higher after surgery. The increased rfCSA values of the PS at L3-S1 in the S1 screw non-loosening group were significantly higher than those in the S1 screw loosening group. The regression analysis showed male, lower CT value of L1 and longer segment fusion were independent risk factors for S1 screw loosening, and postoperative hypertrophy of the PS was a protective factor for S1 screw loosening. CONCLUSIONS: Compared to the preoperative muscle, the PS size increased and fatty infiltration decreased after surgery from L2-3 to L5-S1 in patients with DLSS after short-segment lumbar fusion surgery. Postoperative hypertrophy of the PS might be considered as a protective factor for S1 screw loosening. MRI morphometric parameters and postoperative selected exercise of PS for DLSS patients after posterior lumbar fusion surgery might contribute to improvement of surgical outcome.

Predicting delayed extubation and transfer to the intensive care unit in children undergoing posterior fusion surgery for scoliosis : A retrospective observational study.

BACKGROUND: Delayed extubation and transfer to the intensive care unit (ICU) in children undergoing major scoliosis surgery may increase postoperative complications, prolong hospital stay, and increase medical expenses; however, whether a child will require delayed extubation or transfer to the ICU after scoliosis orthopedic surgery is not fully understood. In this study, we reviewed the risk factors for delayed extubation and transfer to the ICU after scoliosis orthopedic surgery in children. METHOD: The electronic medical records of pediatric patients (≤ 18 years) who underwent posterior spinal fusion surgery between January 2018 and November 2021 were reviewed and analyzed. Patient characteristics (age, sex, body mass index, American Society of Anesthesiologists, ASA, grade, preoperative lung function, and congenital heart disease), preoperative Cobb angle, scoliosis type, correction rate, vertebral fusion segments, pedicle screws, surgical osteotomy, intraoperative bleeding, intraoperative allogeneic transfusion, intraoperative hemoglobin changes, intraoperative mean arterial pressure changes, intraoperative tidal volume (ml/kg predicted body weight), surgical time, postoperative extubation, and transfer to the ICU were collected. The primary outcomes were delayed extubation and transfer to the ICU. Multivariate logistic regression models were used to determine the risk factors for delayed extubation and ICU transfer. RESULTS: A total of 246 children who satisfied the inclusion criteria were enrolled in this study, of whom 23 (9.3%) had delayed extubation and 81 (32.9%) were transferred to the ICU after surgery. High ASA grade (odds ratio [OR] 5.42; 95% confidence interval [CI] 1.49-19.78; p = 0.010), high Cobb angle (OR 1.04; 95% CI 1.02-1.07; p < 0.001), moderate to severe pulmonary dysfunction (OR 10.9; 95% CI 2.00-59.08; p = 0.006) and prolonged surgical time (OR 1.01; 95% CI 1.00-1.03; p = 0.040) were risk factors for delayed extubation. A high Cobb angle (OR 1.02; 95% CI 1.01-1.04; p = 0.004), high intraoperative bleeding volume (OR 1.06; 95% CI 1.03-1.10; p = 0.001), allogeneic transfusion (OR 3.30; 95% CI 1.24-8.83; p = 0.017) and neuromuscular scoliosis (OR 5.38; 95% CI 1.59-18.25; p = 0.007) were risk factors for transfer to the ICU. A high Cobb angle was a risk factor for both delayed extubation and ICU transfer. Age, sex, body mass index, number of vertebral fusion segments, correction rate, and intraoperative tidal volume were not associated with delayed postoperative extubation and ICU transfer. CONCLUSION: The most common risk factor for delayed extubation and ICU transfer in pediatric patients who underwent posterior spinal fusion was a high Cobb angle. Determining risk factors for a poor prognosis may help optimize perioperative respiratory management strategies and planning of postoperative care for children undergoing complicated spinal surgery.

Same-Day Versus Staged Spinal Fusion: A Meta-analysis of Clinical Outcomes.

STUDY DESIGN: Meta-analysis. OBJECTIVE: This meta-analysis aims to compare same-day versus staged spine surgery, assessing their effects on patient care and health care system efficiency. BACKGROUND: In spinal surgery, the debate between whether same-day and staged surgeries are better for patients continues, as the decision may impact patient-related outcomes, health care resources, and overall costs. While some surgeons advocate for staged surgeries, citing reduced risks of complications, others proclaim same-day surgeries may minimize costs and length of hospital stays. METHODS: PubMed, Cochrane, and Google Scholar (pages 1-20) were searched up until February 2024. The studied outcomes were operative room (OR) time, estimated blood loss (EBL), length of hospital stay (LOS), overall complications, venous thromboembolism (VTE), death, operations, and nonhome discharge. RESULTS: Sixteen retrospective studies were included in this meta-analysis, representing a total of 2346 patients, of which 644 underwent staged spinal fusion surgeries and 1702 same-day surgeries. No statistically significant difference was observed in EBL between staged and same-day surgery groups. However, the staged group exhibited a statistically significant longer OR time ( P =0.05) and LOS ( P =0.004). A higher rate of overall complications ( P =0.002) and VTE ( P =0.0008) was significantly associated with the staged group. No significant differences were found in the rates of death, reoperations, and nonhome discharge between the 2 groups. CONCLUSIONS: Both staged and same-day spinal fusion surgeries showed comparable rates of death, operations, and nonhome discharges for patients undergoing spinal surgeries. However, given the increased OR time, LOS, and complications associated with staged spinal surgeries, this study supports same-day surgeries when possible to minimize the burden on healthcare resources and enhance efficiency.