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.

The impact of perioperative nonsteroidal anti-inflammatory drugs on the postoperative outcomes of spinal surgery: a meta-analysis of 23 randomized controlled trials.

In recent years, nonsteroidal anti-inflammatory drug (NSAIDs), which are considered to affect the prognosis of spinal surgery, have been widely used in perioperative analgesia in spinal surgery, but the relationship between these two factors remains unclear. The purpose of this study was to explore the effect of perioperative use of NSAIDs on the prognosis of patients treated with spinal surgery. We systematically searched PubMed, Embase, and Cochrane Library for relevant articles published on or before July 14, 2023. We used a random-effect model for the meta-analysis to calculate the standardized mean difference (SMD) with a 95% confidence interval (CI). Sensitivity analyses were conducted to analyze stability. A total of 23 randomized clinical trials including 1457 participants met the inclusion criteria. Meta-analysis showed that NSAIDs were significantly associated with postoperative morphine use (mg) (SMD = -0.90, 95% CI -1.12 to -0.68) and postoperative pain (SMD = -0.71, 95% CI -0.85 to -0.58). These results were further confirmed by the trim-and-fill procedure and leave-one-out sensitivity analyses. The current study shows that perioperative use of NSAIDs appears to be an important factor in reducing postoperative pain and morphine use in patients undergoing spinal surgery. However, well-designed, high-quality randomized controlled trials (RCTs) are still required.

Risk factors of postoperative delirium following spine surgery: A meta-analysis of 50 cohort studies with 1.1 million participants.

Objectives: Postoperative delirium (POD) is considered to be a common complication of spine surgery. Although many studies have reported the risk factors associated with POD, the results remain unclear. Therefore, we performed a meta-analysis to identify risk factors for POD among patients following spinal surgery. Methods: We systematically searched the PubMed, Embase and the Cochrane Library for relevant articles published from 2006 to February 1, 2023 that reported risk factors associated with the incidence of POD among patients undergoing spinal surgery. The Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed, and random effects models were used to estimate pooled odds ratio (OR) estimates with 95 % confidence intervals (CIs) for each factor. The evidence from observational studies was classified according to Egger's P value, total sample size, and heterogeneity between studies. Results: Of 11,329 citations screened, 50 cohort studies involving 1,182,719 participants met the inclusion criteria. High-quality evidence indicated that POD was associated with hypertension, diabetes mellitus, cardiovascular disease, pulmonary disease, older age (>65 years), patients experiencing substance use disorder (take drug ≥1 month), cerebrovascular disease, kidney disease, neurological disorder, parkinsonism, cervical surgery, surgical site infection, postoperative fever, postoperative urinary tract infection, and admission to the intensive care unit (ICU). Moderate-quality evidence indicated that POD was associated with depression, American Society of Anesthesiologists (ASA) fitness grade (>II), blood transfusion, abnormal potassium, electrolyte disorder, length of stay, inability to ambulate and intravenous fluid volume. Conclusions: Conspicuous risk factors for POD were mainly patient- and surgery-related. These findings help clinicians identify high-risk patients with POD following spinal surgery and recognize the importance of early intervention.

Risk factors for lumbar disc herniation recurrence after percutaneous endoscopic lumbar discectomy: a meta-analysis of 58 cohort studies.

Recurrent lumbar disc herniation (rLDH) is one of the most serious complications and major causes of surgical failure and paralysis following percutaneous endoscopic lumbar discectomy (PELD). There are reports in the literature on the identification of risk factors associated with rLDH; however, the results are controversial. Therefore, we conducted a meta-analysis to identify risk factors for rLDH among patients following spinal surgery. PubMed, EMBASE, and the Cochrane Library were searched without language restrictions from inception to April 2018 for studies reporting risk factors for LDH recurrence after PELD. MOOSE guidelines were followed in this meta-analysis. We used a random effects model to aggregate odds ratios (ORs) with 95% confidence intervals (CIs). The evidence of observational studies was classified into high quality (class I), medium quality (class II/III), and low quality (class IV) based on the P value of the total sample size and heterogeneity between studies. Fifty-eight studies were identified with a mean follow-up of 38.8 months. Studies with high-quality (class I) evidence showed that postoperative LDH recurrence after PELD was significantly correlated with diabetes (OR, 1.64; 95% CI, 1.14 to 2.31), the protrusion type LDH (OR, 1.62; 95% CI, 1.02 to 2.61), and less experienced surgeons (OR, 1.54; 95% CI, 1.10 to 2.16). Studies with medium-quality (class II or III) evidence showed that postoperative LDH recurrence was significantly correlated with advanced age (OR, 1.11; 95% CI, 1.05 to 1.19), Modic changes (OR, 2.23; 95% CI, 1.53 to 2.29), smoking (OR, 1.31; 95% CI, 1.00 to 1.71), no college education (OR, 1.56; 95% CI, 1.05 to 2.31), obesity (BMI ≥ 25 kg/m2) (OR, 1.66; 95% CI, 1.11 to 2.47), and inappropriate manual labor (OR, 2.18; 95% CI, 1.33 to 3.59). Based on the current literature, eight patient-related and one surgery-related risk factor are predictors of postoperative LDH recurrence after PELD. These findings may help clinicians raise awareness of early intervention for patients at high risk of LDH recurrence after PELD.

Risk factors of epidural hematoma in patients undergoing spinal surgery: a meta-analysis of 29 cohort studies.

OBJECTIVE: The authors conducted this meta-analysis to identify risk factors for spinal epidural haematoma (SEH) among patients following spinal surgery. METHODS: The authors systematically searched Pub: Med, Embase, and the Cochrane Library for articles that reported risk factors associated with the development of SEH in patients undergoing spinal surgery from inception to 2 July 2022. The pooled odds ratio (OR) was estimated using a random-effects model for each investigated factor. The evidence of observational studies was classified as high quality (Class I), moderate quality (Class II or III) and low quality (Class IV) based on sample size, Egger's P value and between-study heterogeneity. In addition, subgroup analyses stratified by study baseline characteristics and leave-one-out sensitivity analyses were performed to explore the potential sources of heterogeneity and the stability of the results. RESULTS: Of 21 791 articles screened, 29 unique cohort studies comprising 150 252 patients were included in the data synthesis. Studies with high-quality evidence showed that older patients (≥60 years) (OR, 1.35; 95% CI, 1.03-1.77) were at higher risk for SEH. Studies with moderate-quality evidence suggested that patients with a BMI greater than or equal to 25 kg/m² (OR, 1.39; 95% CI, 1.10-1.76), hypertension (OR, 1.67; 95% CI, 1.28-2.17), and diabetes (OR, 1.25; 95% CI, 1.01-1.55) and those undergoing revision surgery (OR, 1.92; 95% CI, 1.15-3.25) and multilevel procedures (OR, 5.20; 95% CI, 2.89-9.37) were at higher risk for SEH. Meta-analysis revealed no association between tobacco use, operative time, anticoagulant use or American Society of Anesthesiologists (ASA) classification and SEH. CONCLUSIONS: Obvious risk factors for SEH include four patient-related risk factors, including older age, obesity, hypertension and diabetes, and two surgery-related risk factors, including revision surgery and multilevel procedures. These findings, however, must be interpreted with caution because most of these risk factors had small effect sizes. Nonetheless, they may help clinicians identify high-risk patients to improve prognosis.