Evolution of polyetheretherketone (PEEK) and titanium interbody devices for spinal procedures: a comprehensive review of the literature.

INTRODUCTION: Interbody fusion is commonly utilized for arthrodesis and stability among patients undergoing spine surgery. Over the last few decades, interbody device materials, such as titanium and polyetheretherketone (PEEK), have been replacing traditional autografts and allografts for interbody fusion. As such, with the exponential growth of bioengineering, a large variety cage surface technologies exist. Different combinations of cage component materials and surface modifications have been created to optimize interbody constructs for surgical use. This review aims to provide a comprehensive overview of common surface technologies, their performance in the clinical setting, and recent modifications and material combinations. MATERIALS AND METHODS: We performed a comprehensive review of the literature on titanium and PEEK as medical devices between 1964 and 2021. We searched five major databases, resulting in 4974 records. Articles were screened for inclusion manually by two independent reviewers, resulting in 237 articles included for review. CONCLUSION: Interbody devices have rapidly evolved over the last few decades. Biomaterial and biomechanical modifications have allowed for continued design optimization. While titanium has a high osseointegrative capacity, it also has a high elastic modulus and is radio-opaque. PEEK, on the other hand, has a lower elastic modulus and is radiolucent, though PEEK has poor osseointegrative capacity. Surface modifications, material development advancements, and hybrid material devices have been utilized in search of an optimal spinal implant which maximizes the advantages and minimizes the disadvantages of each interbody material.

Does Direct Surgical Repair Benefit Pars Interarticularis Fracture? A Systematic Review and Meta-analysis.

BACKGROUND: Promising results have been shown in previous studies from direct pars interarticularis repair. These include Scott wiring, Buck repair, pedicle screw repair, and Morscher techniques. In addition, several minimally invasive techniques have been reported to show high union rates, low rates of implant failure and wound complications, shorter length of stay, a lower postoperative pain score with faster recovery, and minimal blood loss. OBJECTIVES: To compare the evidence on techniques for direct pars interarticularis repair. STUDY DESIGN: Systematic review and meta-analysis. SETTING: Review article. METHODS: We conducted a comprehensive search of databases to identify studies assessing outcomes of direct pars interarticularis defect repair. Two authors independently screened electronic search results, performed study selection, and extracted data for meta-analysis. Sensitivity and subgroup analyses were performed to assess risk of bias. RESULTS: Forty studies were included in the final analysis. Union rate was higher in the pedicle screw repair group (effect size [ES] 95%; 95% CI, 86% to 100%), followed by the Buck repair group (ES 93%; 95% CI, 86% to 98%), Scott wiring (ES 85%; 95% CI, 63% to 99%), and Morscher method group (ES 63%; 95% CI, 2% to 100%). Positive functional outcome was higher for the Morscher method (ES 91%; 95% CI, 86% to 96%), followed by the Buck repair group (ES 85%; 95% CI, 68% to 97%), pedicle screw repair (ES 84%; 95% CI, 59% to 99%) and Scott repair group (ES 80%; 95% CI, 60% to 95%). Complication rates were highest among the Scott repair group (ES 12%; 95% CI, 4% to 22%) and Morscher method group (ES 12%; 95% CI, 0% to 34%). LIMITATIONS: Heterogeneity of the included studies were noted. However, we performed sensitivity analyses from the available data to address this issue. CONCLUSION: Our results indicate that pedicle screw repair and Buck repair may be associated with a higher union rate and lower complication rates compared to the Scott repair and Morscher method. Ultimately, the choice of technique should be based on the surgeon's preference and experience.

Survival and associated predictors for patients with pineoblastoma or pineal parenchymal tumors of intermediate differentiation older than 3 years: Insights from the National Cancer Database.

Background: The management of pineal parenchymal tumors remains controversial. Methods: The 2004-2017 National Cancer Database was queried for cases (age >3 years) with histologically confirmed pineal parenchymal tumors of intermediate differentiation (PPTID, n = 90) or pineoblastoma (n = 106). Results: Within the PPTID group, median age was 41 years; 49% were males. Five- and 10-year survival were 83% and 78%, respectively. Adjuvant radiation and chemotherapy were administered in 64% and 17% patients, respectively. The effect of radiation with or without chemotherapy (HR 1.15, P = .81, and HR 1.31, P = .72, respectively), and extent of resection (HR = 1.07, P = .93) was not significant. Within the pineoblastoma group, median age was 25 years; 51% were males. Five- and 10-year survival were 66% and 42%, respectively. Adjuvant radiation and chemotherapy were administered in 72% and 51%, respectively. In multivariable analysis, patients with pineoblastoma who received both radiation and chemotherapy (n = 39) had significantly lower hazard of death (HR 0.35, 95% CI 0.14-0.85, P = .02) compared to those who received radiation alone (n = 20) or no adjuvant treatment (n = 19). Finally, females in the pineoblastoma group were found to have a lower hazard of death compared to males (HR 0.24, 95% CI 0.10-0.58, P = .001); this comparison trended toward statistical significance in the PPTID subgroup (HR 0.40, 95% CI 0.14-1.08, P = .07). Conclusions: Survival rates were higher in patients with PPTID vs patients with pineoblastoma. Adjuvant chemoradiation was associated with improved survival in pineoblastoma and females had lower hazards of death. Further research should identify specific patient profiles and molecular subgroups more likely to benefit from multimodality therapy.

Direct Pars Repair with Cannulated Screws in Adults: A Case Series and Systematic Literature Review.

OBJECTIVE: Lumbar spondylolysis occurs in 5%-8% of adults. This study aimed to report clinical and radiographic outcomes of direct pars repair in adults with lumbar spondylolysis. METHODS: We conducted a retrospective review of all patients treated for lumbar spondylolysis via open fracture reduction and direct pars repair with cannulated screws using a lag technique. Demographics, clinical presentation, perioperative and intraoperative imaging, and postoperative data were collected. We subsequently performed a systematic review to describe radiographic and clinical outcomes following direct pars repair. RESULTS: Three patients were identified (mean age 40.3 years; range, 21-72 years; 2 male). All patients had bilateral L5 pars fractures treated via open, direct repair with cannulated screws. There were no intraoperative complications. Length of stay was <24 hours for each patient. All patients reported back/radicular symptom relief and returned to full-time manual labor by latest follow-up. Noncontrast lumbar computed tomography performed 14-20 months postoperatively confirmed that all patients had good bilateral screw placement without fracture. Two patients (21 and 28 years old at surgery) had evidence of fusion across fracture sites, while 1 patient exhibited radiolucency around the screws and no progression of spondylolisthesis. Additionally, we reviewed 8210 articles and included 15 in a systematic review of direct pars repair. Fusion rates were 67%-100%, with improved average Oswestry Disability Index and visual analog scale back pain scores by latest follow-up. CONCLUSIONS: Lumbar spondylolysis treatment with open fracture reduction and direct pars repair with cannulated screws in adults is safe and may result in mechanical back/radicular pain relief, even in the absence of radiographic fusion.

Trends in Admissions and Outcomes for Treatment of Aneurysmal Subarachnoid Hemorrhage in the United States.

BACKGROUND: Lifestyle modifications and advances in surgical and endovascular techniques for treating unruptured intracranial aneurysm (UIA) have vastly evolved over the last few decades and may have reduced the incidence of aneurysmal subarachnoid hemorrhage (aSAH). However, the actual impact of these changes on the rates and outcomes of aSAH remain unexplored. Thus, we studied national aSAH admissions and outcome trends and changes of major risk factors over time. METHODS: We queried the National Inpatient Sample between 2006 and 2018 to identify adult patients admitted and treated for UIA or ruptured aneurysm with aSAH. The Cochran-Armitage test was conducted to assess the linear trend of proportion of prevalence, inpatient mortality, hypertension, and current smoking status among aSAH admissions. Multivariable logistic regression was conducted to assess the odds of presenting with aSAH versus UIA, in addition to the odds of inpatient mortality among patients with aSAH. RESULTS: A total of 159,913 patients presented with UIA and 133,567 presented with aSAH. Admissions for aSAH decreased by 0.97% (p < 0.001) per year. Current smoking and hypertension were associated with higher odds of being admitted for aSAH compared with the treatment for UIA (odds ratio [OR] 1.38, 95% confidence interval [CI] 1.29-1.48; OR 1.15, 95% CI 1.08-1.22, respectively). Compared with White patients, Black patients (OR 1.32, 95% CI 1.21-1.43), Hispanic patients (OR 1.38, 95% CI 1.25-1.52), and patients of other races and/or ethnicities (OR 1.73, 95% CI 1.54-1.95) had a higher chance of presenting with aSAH. Rates of inpatient mortality among aSAH admissions showed no change over time (p = 0.21). Among patients admitted with aSAH, current smoking and hypertension showed an upward trend of 0.58% (p < 0.001) and 1.60% (p < 0.001) per year, respectively. CONCLUSIONS: Despite a downward trend in the annual frequency of hospitalizations for aSAH, inpatient mortality rates for patients undergoing treatment of the ruptured aneurysm have remained unchanged in the United States. Smoking and hypertension are increasingly prevalent among patients with aSAH. Thus, efforts to control these modifiable risk factors must be further strengthened.

Nervous system involvement in SARS-coronavirus infection: a review on lessons learned from the previous outbreaks, ongoing pandemic and what to expect in the future.

Viral infections have been associated with the deleterious damage to nervous system resulting in impairment of the central nervous system as late sequalae infections. Since the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), several studies have reported patients developing adverse neurological signs and symptoms. Like the outbreak of SARS in 2003, the recent outbreak has undermined the norm of the nervous system. This review will summarize the possible mechanism of neurological manifestations, the clinical presentations of patients with such symptoms secondary to SARS coronaviruses, and the prospective role of neurology and neurosurgery practice in managing these symptoms in the current climate.

Time-to-enrollment in clinical trials investigating neurological recovery in chronic spinal cord injury: observations from a systematic review and ClinicalTrials.gov database.

Currently, large numbers of clinical trials are performed to investigate different forms of experimental therapy for patients suffering from chronic spinal cord injury (SCI). However, for the enrollment process, there are different views on how the time period between injury and interventions should be determined. Herein, we sought to evaluate the impact of time-to-enrollment in chronic SCI clinical trials. A data set comprising 957 clinical studies from clinicalTrials.gov was downloaded and analyzed focusing on the eligibility criteria for post-injury time-to-enrollment. We also aggregated individual patient data from nine clinical trials of regenerative interventions for chronic SCI selected by a systematic literature search from 1990 to 2018. Characteristics of the studies were assessed and compared by dividing into three groups based on time-to-enrollment (group 1 ≤ 12 months, group 2 = 12-23 months and group 3 ≥ 24 months). In ClinicalTrials.gov registry, 445 trials were identified for chronic SCI where 87% (385) were unrestricted in the maximum post-injury time for trial eligibility. From systematic literature search, nine studies and 156 patients (group 1 = 30, group 2 = 55 and group 3 = 71) were included. The range of time-to-enrollment was 0.5 to 321 months in those studies. We also observed various degrees of motor and sensory improvement in between three time-to-enrollment groups. Our results indicate that enrolling wide ranges of time-to-enrollment in a group may present imprecise outcomes. Clinical trial designs should consider appropriate post-injury time frames to evaluate therapeutic benefit.

Hybrid surgery: a comparison of early postoperative outcomes between anterior cervical discectomy and fusion and cervical disc arthroplasty.

OBJECTIVE: Hybrid surgery (HS) is the combination of anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) at different levels in the same operation. The aim of this study was to investigate perioperative variables, 30-day postoperative outcomes, and complications of HS in comparison with those of CDA and ACDF. METHODS: The authors queried the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) registry for patients who underwent multilevel primary HS, CDA, and ACDF for degenerative disc disease from 2015 to 2019. The authors compared these three operations in terms of 30-day postoperative outcomes, specifically readmission and reoperation rates, discharge destination, and complications. RESULTS: This analysis included 439 patients who underwent HS, 976 patients who underwent CDA, and 27,460 patients who underwent ACDF. Patients in the HS and CDA groups were younger, had fewer comorbidities, and myelopathy was less often the indication for surgery compared with patients who underwent ACDF. For the HS group, the unplanned readmission rate was 0.7%, index surgery-related reoperation rate was 0.3%, and nonroutine discharge rate was 2.1%. Major and minor complications were also rare, with rates of 0.2% for each. The mean length of stay in the HS group was 1.5 days. The association of HS with better outcomes in univariate analysis was not evident after adjustment for confounding factors. CONCLUSIONS: The authors found that HS was noninferior to ACDF and CDA in terms of early postoperative outcomes among patients treated for degenerative disc disease.

Clinical characteristics and management differences for grade II and III spinal meningiomas.

PURPOSE: The majority of spinal meningiomas are grade I tumors, as defined by World Health Organization (WHO) classification making atypical (grade II) or anaplastic (grade III) tumors extremely rare lesions to encounter in clinical practice. Here, we present our institutional experience of management of grade II and III spinal meningiomas. METHODS: Following IRB approval, we queried all available institutional electronic medical records for patients undergoing surgical resection of pathology-proven spinal meningiomas, with further review of patients with grade II and III. Variables of interest included age, sex, histological type, tumor size, symptoms at baseline, treatment characteristics, symptom resolution at the last follow-up, recurrence, NF-2 status, concurrent intracranial meningioma, and mortality. Kaplan Meier curves were constructed to study time to progression/recurrence. RESULTS: A total of 188 patients undergoing surgical resection of spinal meningioma between 1988 and 2018 were identified. Among those, 172 (91.5%) patients had grade I meningioma and 16 (8.5%) patients had high grade meningiomas [grade II (15) and III (1)]. Over a median (IQR) follow-up of 8.0 years (5.1-13.0), mortality and recurrence rates were 18.8% (n = 3) and 47.1% (n = 8), respectively. In univariate analysis, adjuvant radiotherapy and thoracic segment involvement were associated with lower rates of recurrence while male sex was associated with a higher rate of recurrence. CONCLUSIONS: Results showed variations in clinical outcomes for patients with high grade spinal meningiomas, especially the recurrence. Adjuvant radiotherapy and thoracic segment involvement was associated with lower rates of recurrence while recurrence ocurred at a higher rate in males.

Diagnostic yield, accuracy, and complication rate of CT-guided biopsy for spinal lesions: a systematic review and meta-analysis.

BACKGROUND: CT-guided biopsy is a commonly used diagnostic procedure for spinal lesions. This meta-analysis aims to investigate its diagnostic performance and complications, as well as factors influencing outcomes. METHODS: A systematic review of the literature was performed to identify studies reporting outcomes of CT-guided biopsies for spinal lesions. Diagnostic yield (ie, the rate of procedures resulting in a specific pathological diagnosis) and diagnostic accuracy (ie, the rate of procedures resulting in the correct diagnosis) were the primary outcomes of interest. Complications following biopsy procedures were also included. RESULTS: Thirty-nine studies with 3917 patients undergoing 4181 procedures were included. Diagnostic yield per procedure was 91% (95% CI 88% to 94%) among 3598 procedures. The most common reason for non-diagnostic biopsies was inadequacy of sample. No difference in diagnostic yield between different locations and between lytic, sclerotic, and mixed lesions was found. Diagnostic yield did not differ between procedures using ≤13G and ≥14G needles. Diagnostic accuracy per procedure was 86% (95% CI 82% to 89%) among 3054 procedures. Diagnostic accuracy among 2426 procedures that yielded a diagnosis was 94% (95% CI 92% to 96%). Complication rate was 1% (95% CI 0.4% to 1.9%) among 3357 procedures. Transient pain and minor hematoma were the most common complications encountered. CONCLUSION: In our meta-analysis of 39 studies reporting diagnostic performance and complications of CT-guided biopsy, we found a diagnostic yield of 91% and diagnostic accuracy of 86% with a complication rate of 1%. Diagnostic yield did not differ between different locations, between lytic, sclerotic and mixed lesions, and between wide- and thin-bore needles.

Trends in Utilization of Preoperative Embolization for Spinal Metastases: A Study of the National Inpatient Sample 2005-2017.

PURPOSE: While previous studies have suggested that preoperative embolization of hypervascular spinal metastases may alleviate intraoperative blood loss and improve resectability, trends and driving factors for choosing this approach have not been extensively explored. Therefore, we evaluated the trends and assessed the factors associated with preoperative embolization utilization for spinal metastatic tumors using a national inpatient database. MATERIALS AND METHODS: The National Inpatient Sample database of the Healthcare Cost and Utilization Project was queried for patients undergoing surgical resection for spinal metastasis between January 1, 2005 and December 31, 2017. Patients undergoing preoperative embolization were identified; trends in the utilization of preoperative embolization were analyzed using the Cochran-Armitage test. Multivariable regression was conducted to assess factors associated with higher preoperative embolization utilization. RESULTS: A total of 11,508 patients with spinal metastasis were identified; 105 (0.91%) underwent preoperative embolization. Of those 105 patients, 79 (75.24%) patients had a primary renal cancer, as compared to 1,732 (15.19%) of those who did not undergo preoperative embolization (P<0.001). The majority of patients in the non-preoperative embolization cohort had a primary lung tumor (n=3,562, 31.24%). Additionally, patient comorbidities were similar among the 2 groups (P>0.05). Trends in preoperative embolization indicated an increase of 0.16% (standard error: 0.024%, P<0.001) in utilization per year. CONCLUSION: Utilization of preoperative embolization for spinal metastasis is increasing yearly, especially for patients with renal cancer, suggesting that surgeons may increasingly consider embolization before surgical resection for hypervascular tumors. Additionally, the literature has shown the intraoperative and postoperative benefits of this procedure.

The analgesic effect of intravenous lidocaine versus intrawound or epidural bupivacaine for postoperative opioid reduction in spine surgery: A systematic review and meta-analysis.

BACKGROUND: Pain management following spine surgery remains a challenge. The significant use of opioids may lead to opioid-related adverse events. These complications can increase perioperative morbidity and rapidly expend health care resources by developing chronic pain. Although intraoperative pain control for surgery has been studied in the literature, a thorough assessment of the effect in spine surgery is rarely reported. The objective of the present study was to examine the outcomes of intraoperative intravenous lidocaine and intrawound or epidural bupivacaine use in spine surgery. METHODS: An electronic literature search was conducted for studies on the use of lidocaine and bupivacaine in spine surgery for all years available. Only articles in English language were included. Postoperative opioid consumption, VAS score, nausea/vomiting, and length of hospital stay comprised the outcomes of interest. Pooled descriptive statistics with Risk Ratios (RR), Mean Differences (MD) and 95 % confidence interval were used to synthesize the outcomes for each medication. RESULTS: A total of 10 studies (n = 579) were included in the analysis. Comparison of the opioid consumption revealed a significant mean difference between lidocaine and bupivacaine (MD: -12.25, and MD: -0.4, respectively, p = 0.01), favoring lidocaine. With regard to postoperative VAS, the pooled effect of both groups decreased postoperative pain (MD: -0.61 (95 % CI: -1.14, -0.08)), with a more significant effect in the lidocaine group (MD: -0.84, (95 % CI: -1.21, -0.48)). There was no significant effect in length of stay, and postoperative nausea/vomiting. CONCLUSIONS: The results of the present meta-analysis indicate that lidocaine and bupivacaine use may decrease postoperative pain and opioid consumption. Lidocaine had a stronger effect on the reduction of opioid consumption compared to bupivacaine.

Predictors of adverse outcomes and cost after surgical management for idiopathic normal pressure hydrocephalus: Analyses from a national database.

INTRODUCTION: We utilized a national administrative database to investigate drivers of immediate adverse economic and hospital outcomes, including non-routine discharge, prolonged length of stay (LOS), and admission costs among patients undergoing surgery for idiopathic normal pressure hydrocephalus (iNPH). METHODS: The National Inpatient Sample (NIS) was queried from 2007 to 2017 for patients aged ≥60 with a diagnosis code for iNPH undergoing surgery. Multivariable logistic-regression models and Wald χ2 were used to identify drivers of non-routine discharge, prolonged length of stay (LOS) (>75th percentile) and higher admission costs (>90th percentile). RESULTS: A total of 13,363 patients with iNPH undergoing surgical management were identified. The most common comorbidity reported in the cohort was a cardiovascular pathology (56.9 %, n = 7,787), followed by urinary pathology (37.2 %, n = 5,084), osteoarthritis (7.8 %, n = 1,071), Alzheimer's disease (4.6 %, n = 626) and cerebrovascular pathology (4.2 %, n = 569). The most frequently employed procedure was ventriculo-peritoneal (VP) shunt placement (65.6 %, n = 8,942) of which 89.8 % (n = 8,027) were performed open and 10.2 % (n = 915) laparoscopically. This was followed by lumbo-peritoneal (LP) shunting (15.5 %, n = 2,115), lumbar puncture alone (screened, serial CSF removal) (14.8 %, n = 2,013), endoscopic third ventriculostomy (ETV) (2%, n = 274), ventriculo-atrial (VA) shunt (0.95 %, n = 130) and ventriculo-pleural (Vpleural) shunt (0.46 %, n = 64). The median (IQR) LOS was 3 days (2-5), the rate of non-routine discharge was 37.3 % and median (IQR) cost was $11,230 ($7,735-15,590). On multivariable-analysis, emergent-admission (OR 2.91), older age (76-90: OR 1.55; 90+: OR 2.66), VP shunt (open: OR 3.09; laparoscopic: OR 2.32), ETV (OR 3.16), VA/VPleural shunt (OR 2.73) and hospital admission in Northeast-region compared to Midwest (OR 1.27) were found to be associated with increased risk of non-routine discharge. Some of the highly significant associated factors for prolonged LOS included emergent-admission (OR 11.34), ETV (OR 10.92), VA/VPleural shunt (OR 7.79) and open VP shunt (OR 8.24). For increased admission costs, some of the highly associated factors included VA/VPleural shunt (OR 18.48), laparoscopic VP shunt (OR 9.92), open VP shunt (OR 12.72) and ETV (OR 9.34). Predictor importance analysis revealed emergent admission, number of diagnosis codes (comorbidities) open VP shunt, hospital region, age] and revision or removal of shunt to be the most important drivers of these outcomes. CONCLUSION: Analyses from a national database indicate that among patients with iNPH, an emergent-admission may be the most significant risk-factor of adverse economic outcomes and higher costs.

Risk Factors for Unplanned Readmissions Following Anterior Cervical Discectomy and Fusion and Posterior Lumbar Fusion Procedures: Comparison of Two National Databases.

BACKGROUND: The National Surgical Quality Improvement Program (NSQIP) and National Readmission Database (NRD) are 2 widely used databases that provide valuable information regarding the quality of health care. However, the 2 differ in sampling methodology, which may result in conflicting findings when used for research studies. The objective of this study is to evaluate the differences regarding predictors of 30-day readmissions after anterior cervical discectomy and fusion (ACDF) and posterior lumbar fusion (PLF). METHODS: In this case-control study, NSQIP and NRD were queried for patients undergoing elective ACDF and PLF between 2014 and 2015. The outcome of interest was 30-day readmissions following ACDF and PLF, which were unplanned and related to the index procedure. Subsequently, univariable and multivariable analyses were conducted to determine the predictors of 30-day readmissions using both databases. RESULTS: For ACDF procedures, diagnosis, outpatient status, American Society of Anesthesiologists class, and length of hospital stay were found to be significant predictors of 30-day readmissions in NSQIP, whereas only age and hypertension were significant in NRD. Among patients undergoing PLF procedures, body mass index, functional status, smoking, steroid use, diabetes, dyspnea, dialysis, emergency, discharge to rehab facility, and length of hospital stay were found to be significant predictors of 30-day readmissions in NSQIP, whereas only alcohol abuse and obesity were significant predictors in NRD. CONCLUSIONS: Two databases differed in terms of significant predictors of 30-day readmissions following ACDF and PLF. This difference may emphasize the differences in the sampling methodology. Further analyses, potentially with an institutional validation, are needed to draw conclusions regarding the accuracy of the 2 databases for predictive analytics.

Institutional databases may underestimate the risk factors for 30-day unplanned readmissions compared to national databases.

OBJECTIVE: The National Surgical Quality Improvement Program (NSQIP) and National Readmissions Database (NRD) are two widely used databases for research studies. However, they may not provide generalizable information in regard to individual institutions. Therefore, the objective of the present study was to evaluate 30-day readmissions following anterior cervical discectomy and fusion (ACDF) and posterior lumbar fusion (PLF) procedures by using these two national databases and an institutional cohort. METHODS: The NSQIP and NRD were queried for patients undergoing elective ACDF and PLF, with the addition of an institutional cohort. The outcome of interest was 30-day readmissions following ACDF and PLF, which were unplanned and related to the index procedure. Subsequently, univariable and multivariable analyses were conducted to determine the predictors of 30-day readmissions by using both databases and the institutional cohort. RESULTS: Among all identified risk factors, only hypertension was found to be a common risk factor between NRD and the institutional cohort following ACDF. NSQIP and the institutional cohort both showed length of hospital stay to be a significant predictor for 30-day related readmission following PLF. There were no overlapping variables among all 3 cohorts for either ACDF or PLF. Additionally, the national databases identified a greater number of risk factors for 30-day related readmissions than did the institutional cohort for both procedures. CONCLUSIONS: Overall, significant differences were seen among all 3 cohorts with regard to top predictors of 30-day unplanned readmissions following ACDF and PLF. The higher quantity of significant predictors found in the national databases may suggest that looking at single-institution series for such analyses may result in underestimation of important variables affecting patient outcomes, and that big data may be helpful in addressing this concern.

Outpatient Versus Inpatient Posterior Lumbar Fusion for Low-Risk Patients: An Analysis of Thirty-Day Outcomes From the National Surgical Quality Improvement Program.

BACKGROUND: Outpatient spine surgery has been increasingly used recently owing to its perceived cost benefits and its ability to offset the volume from the inpatient setting. However, the 30-day outcomes of outpatient posterior lumbar fusion (PLF) for low-risk patients have not been extensively studied. In the present study, we assessed the 30-day outcomes of outpatient PLF surgery for low-risk patients using a national surgical quality registry. METHODS: For the present study, we queried the American College of Surgeons National Surgical Quality Improvement Program for patients who had undergone PLF from 2009 to 2016. Only patients with an American Society of Anesthesiologists grade of 1-2 were included. The 30-day outcomes, including any complications, readmissions, and reoperations, were studied using multivariable logistic regression after adjustment for an array of patient-specific factors. RESULTS: A total of 29,830 cases were identified. Of these 29,830 cases, 1016 (3.4%) had been performed as outpatient cases and 28,814 (96.6%) as inpatient. After adjusting for an array of patient-specific factors, we did not find any significant association between the procedure setting and complication rate (odds ratio [OR], 0.8; 95% confidence interval [CI], 0.6-1.1; P = 0.15) or 30-day readmission rate (OR, 0.9; 95% CI, 0.6-1.4; P = 0.76). Patients undergoing outpatient PLF were more likely to have required a 30-day reoperation (OR, 1.6; 95% CI, 1.1-2.4; P = 0.02). CONCLUSION: Our results have demonstrated that the 30-day outcomes of patients who have undergone outpatient PLF might be comparable to those of patients who have undergone PLF in an inpatient setting. However, outpatient surgery might be associated with a greater overall reoperation rate.

Factors Associated with Higher Rates of Heterotopic Ossification after Spinal Cord Injury: A Systematic Review and Meta-Analysis.

Heterotopic Ossification (HO) refers to the formation of bone within soft tissue. Traumatic spinal cord injury (SCI) has been shown to be associated with development of HO. However, risk factors for HO following SCI are unknown. In light of this knowledge gap, we performed a systematic review and meta-analysis to summarize available evidence and elucidate risk factors associated with heterotopic ossification. An electronic literature search was conducted using five databases. Studies containing SCI patients, with a proportion diagnosed with HO, were included. Meta-analyses were performed to assess the association between following risk factors and development of HO: sex, type of injury, spasticity, pressure ulcer, injury level, urinary tract infection (UTI), deep vein thrombosis (DVT), number of smokers, and pneumonia. Nine studies with 2,115 patients were included. It was found that males (Odds Ratio [95% Confidence Interval]: 2.25 [1.61, 3.13]), smokers (2.88 [1.62, 5.11]), patients with complete injury (3.61 [2.29, 5.71]), pneumonia (2.86 [2.18, 3.75]), pressure ulcers (2.45 [1.89, 3.18]), UTI (3.84 [2.63, 5.62]) and spasticity (2.12 [1.67, 2.68]) had significantly higher odds of developing HO after spinal cord injury. In contrast, location of injury (Cervical vs. thoracic injury; (1.03 [0.72, 1.49]) and DVT (1.37 [0.91, 2.07]) were not associated with development of HO. Pooled results from existing literature on HO development show that several factors are significantly associated with development of HO. Given the complexity of SCI management, the results might have a positive impact on the clinical practice by leading to an effective screening aproach.

Use of regenerative treatments in treatment of lumbar Degenerative Disc Disease: A systematic review.

Low back pain due to lumbar Degenerative Disc Disease (DDD) is one of the most common causes of disability and morbidity, particularly among older adults. Current research efforts in lumbar DDD management are shifting towards identifying and correcting the pathology in intervertebral discs without any external manipulation. Herein, we present a systematic review of current literature regarding regenerative treatments for lumbar DDD. An electronic search of databases including PubMed, Ovid/MEDLINE, Cochrane and Scopus was conducted for articles in all available years. Studies that investigated treatment for discogenic pain in lumbar DDD, including any type of stem cell or bone marrow concentrate as the treatment agent and studies that report both baseline and follow-up pain and Oswestry Disability Index (ODI) scores were included in the review. Changes in pain and ODI scores were calculated for 3-month, 6-month and 12-month periods. Six studies with a total of 93 patients were evaluated. Mean (SD) age of the pooled sample was 40.0(8.1) and 39.5% (32/81) of patients were female. Pain improvement was reported in 38.8% of patients at 3-month, 40.8% at 6-month and 44.1% at 12-month follow-up. Average improvement in ODI score for 3-month, 6-month and 12-month follow-ups was calculated to be 24.0, 26.5 and 25.7, respectively. Regenerative treatments are being increasingly employed across all spectrums of medicine. Review of six single arm studies revealed a potential positive impact in the preliminary results. However, these promising 'preliminary' results should not be interpreted as the definite treatment and should be validated with further prospective studies.

The impact of platelet-rich plasma on postoperative outcomes after spinal fusion: a systematic review and meta-analysis.

OBJECTIVE: Platelet-rich plasma (PRP) is a biological agent obtained by centrifuging a sample of blood and retrieving a high concentration of platelets and plasma components. The concentrate is then stimulated for platelet secretion of various growth factors and cytokines. Although it is not widely used in clinical practice, its role in augmenting bony union among patients undergoing spinal fusion has been assessed in several clinical studies. The objective of this study was to perform a systematic review and meta-analysis of the existing literature to determine the efficacy of PRP use in spinal fusion procedures. METHODS: A comprehensive literature search was conducted using PubMed, Scopus, and EMBASE for studies from all available dates. From eligible studies, data regarding the fusion rate and method of assessing fusion, estimated blood loss (EBL), and baseline and final visual analog scale (VAS) scores were collected as the primary outcomes of interest. Patients were grouped by those undergoing spinal fusion with PRP and bone graft (PRP group) and those only with bone graft (graft-only group). RESULTS: The literature search resulted in 207 articles. Forty-five full-text articles were screened, of which 11 studies were included, resulting in a meta-analysis including 741 patients. Patients without PRP were more likely to have a successful fusion at the last follow-up compared with those with PRP in their bone grafts (OR 0.53, 95% CI 0.34-0.84; p = 0.006). There was no statistically significant difference with regard to change in VAS scores (OR 0.00, 95% CI -2.84 to 2.84; p > 0.99) or change in EBL (OR 3.67, 95% CI -67.13-74.48; p = 0.92) between the groups. CONCLUSIONS: This study found that the additional use of PRP was not associated with any significant improvement in patient-reported outcomes and was actually found to be associated with lower fusion rates compared with standard grafting techniques. Thus, PRP may have a limited role in augmenting spinal fusion.

Pharmacologic prophylaxis for heterotopic ossification following spinal cord injury: A systematic review and meta-analysi.

Heterotopic ossification(HO) is a common complication following spinal cord injury(SCI); however, its underlying pathophysiology remains relatively unknown. Although there are options for treating HO, prophylactic treatment is limited. Additionally, evidence supporting the effectiveness of these prophylactic treatments is scarce. Electronic literature search was conducted using four databases. Studies comparing prophylactic medication for HO versus placebo for patients with acute spinal cord injury were included. A meta-analysis comparing the incidence of HO between the two groups was conducted, with a subgroup analysis of non-steroidal anti-inflammatory drugs (NSAIDs) and non-NSAIDs. A total of 5 studies and 815 patients were included. Overall incidence of HO was 9.73 % (n = 25) in the medication group versus 16.5 %(n = 92) in the placebo group. However, the two groups do not statistcally differ(p = 0.21). In the subgroup analysis for NSAIDs, those who received prophylactic treatment with NSAIDs had a lower incidence of HO compared to those who received placebo (RR[95 % CI]:0.32[0.15, 0.68]; p = 0.003). As for studies that used bisphosphonates, a statistically significant difference in incidence of HO was not found (RR[95 % CI]:1.30[0.52, 3.24];p = 0.58) and the overall evidence was inconclusive. In present systematic review and meta-analysis comparing prophylactic medications to placebo for prevention of HO, we found similar incidence rates for both groups. However, subgroup analysis showed a significantly lower incidence rate for those who recevied NSAIDs for HO prophylaxis. Altough this finding is promising for secondary prevention of HO among patients suffering from SCI, further prospective studies with longer follow-ups are required to assess other appropriate medications for HO prevention.