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Purpose: To compare the clinical effectiveness of reduction and fusion with in situ fusion in the management of patients with degenerative lumbar spondylolisthesis (DLS)., Methods: The systematic review was conducted following the PRISMA guidelines. Relevant studies were identified from PubMed, Embase, Scopus, Cochrane Library, ClinicalTrials.gov, and Google Scholar. The inclusion criteria were: (1) comparative studies of reduction and fusion versus in situ fusion for DLS patients, (2) outcomes reported as VAS/NRS, ODI, JOA score, operating time, blood loss, complication rate, fusion rate, or reoperation rate, (3) randomized controlled trials and observational studies published in English from the inception of the databases to January 2023. The exclusion criteria included: (1) reviews, case series, case reports, letters, and conference reports, (2) in vitro biomechanical studies and computational modeling studies, (3) no report on study outcomes. The risk of bias 2 (RoB2) tool and the Newcastle-Ottawa scale was conducted to assess the risk of bias of RCTs and observational studies, respectively., Results: Five studies with a total of 704 patients were included (375 reduction and fusion, 329 in situ fusion). Operating time was significantly longer in the reduction and fusion group compared to in situ fusion group (weighted mean difference 7.20; 95% confidence interval 0.19, 14.21; P = 0.04). No additional significant intergroup differences were noted in terms of other outcomes analyzed., Conclusion: While the reduction and fusion group demonstrated a statistically longer operating time compared to the in situ fusion group, the clinical significance of this difference was minimal. The findings suggest no substantial superiority of lumbar fusion with reduction over without reduction for the management of DLS., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: Lower back pain (LBP) has been implicated as a significant cause of chronic pain in the United States, often requiring analgesic use. In this study, we investigate the trends in long-term preoperative NSAID (LTN) and Opioid (LTO) use in patients with low back pain in the United States, and the resultant postoperative complications following lumbar fusion., Methods: In this retrospective cohort study of patients with lumbar pathologies, multivariate population-based regression models were developed using the 2010-2017 National Readmission Database. Short-term complications (30-, 90-day) and long-term complications (180-, 300-day) were analyzed at readmission., Results: Of patients diagnosed with LBP (N = 1427,190) we found a rise in LTO users and a fall in LTN users following 2015. We identified 654,264 individuals who received a lumbar spine fusion, of which 22,975 were LTN users and 11,213 were LTO users. LTO users had significantly higher total inpatient charges (p-value<0.0001) and LOS (p-value<0.0001), while LTN users had lower rates of acute infection (OR: 0.993, 95% CI: 0.987-0.999, p = 0.017) and acute posthemorrhagic anemia (OR: 0.957, 95% CI: 0.935-0.979, p < 0.001) at primary admission. Readmission analysis showed that LTN use had significantly lower odds of readmission compared to LTO use at all time points (p < 0.01 for all). LTN use had significantly higher odds of hardware failure (OR: 1.134, 95% CI: 1.039-1.237, p = 0.005) within 300-days of receiving a lumbar fusion., Conclusions: LTO users had significantly higher readmission rates compared to LTN. In addition, we found that LTN use was associated with significantly higher odds of hardware failure at long-term follow-up in patients receiving lumbar fusion surgery., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Study Design: Retrospective cohort study., Objective: To analyze the effect of hyperlipidemia (HLD) on postoperative complications in patients who underwent anterior cervical discectomy and fusion (ACDF)., Summary of Background Data: ACDF represents the standard procedure performed for focal anterior nerve root or spinal cord compression with low complication rates. HLD is well known as a risk factor for major complications after vascular and transplant surgery, and orthopedic surgery. To date, there have been no studies on HLD as a risk factor for cervical spine surgery., Patients and Methods: Patients who underwent ACDF from 2010 through quarter 3 of 2020 were enrolled using the MSpine subset of the PearlDiver Patient Record Database. The patients were divided into single-level ACDF and multilevel ACDF groups. In addition, each group was divided into subgroups according to the presence or absence of HLD. The incidence of surgical and medical complications was queried using relevant International Classification of Disease and Current Procedural Terminology codes. Charlson Comorbidity Index was used as a broad measure of comorbidity. χ 2 analysis, with populations matched for age, sex, and Charlson Comorbidity Index, was performed., Results: A total of 24,936 patients who underwent single-level ACDF and 26,921 patients who underwent multilevel ACDF were included. In the multilevel ACDF group, wound complications were significantly higher in the patients with HLD. Among medical complications, myocardial infarction, renal failure, and urinary tract infection/urinary incontinence were significantly higher in the patients with HLD in both groups. Revision surgery and readmission were significantly higher in the patients with HLD who underwent multilevel ACDF., Conclusions: In patients who underwent ACDF, several surgical and medical complications were found to be higher in patients with HLD than in patients without HLD. Preoperative serum lipid concentration levels and management of HLD should be considered during preoperative planning to prevent postoperative complications in patients undergoing ACDF., Competing Interests: Z.B.–Grants/Research support: AO Spine (co-PI on a AO Spine Knowledge Forum grant, Paid directly to institution/employer); Nexus Spine (Paid directly to institution/employer), Medical Metrics (Paid directly to institution/employer); MiMedx (past, Paid directly to institution/employer), SBIR NIH (past, Paid directly to institution/employer); Medical Metrics (past, Paid directly to institution/employer); Next Science (past, Paid directly to institution/employer); Consultancy: Next Science (paid directly to institution/employer); NIH (advisor consultant); Scientific Advisory Board: Medtronic, Medical Metrics; Trips/Travel: AO Spine (Travel Expense Reimbursement, travel reimbursements for AO Spine Knowledge forum meetings and congresses), NASS (Travel Expense Reimbursement); Board of Directors: LSRS (Nonfinancial, Co-chair of Program Committee); Committees: AO Spine Knowledge Forum Degenerative (Steering Committee Member); North American Spine Society: Research Project Management Committee (Vice chair), Section on Biologics & Basic Research (Co-chair), The Spine Journal Peer Reviewers (Committee member). Patents (issued): Biomarkers for painful intervertebral discs and methods of use thereof. J.C.W.-royalties: SeaSpine, Depuy, Zimmer; consulting - Precision OS (no money paid); expert testimony; AO Foundation Board (honorarium), National Spine Health Foundation (volunteer); stocks/personal investment: PearlDiver, Bone Biologics, Surgitech; Fellowship Funding (paid to institution): AO Foundation. The remaining authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: A retrospective database study., Objectives: The purpose of the current study was to investigate the impact of hyperlipidemia (HLD) on the incidence of perioperative complications associated with posterior cervical spine fusion (PCF)., Background: HLD is a very common disease that leads to atherosclerosis. Therefore, it can cause fatal diseases as well as lifestyle-related diseases. The possible impact of HLD on outcomes after PCF has not yet been investigated., Methods: Patients with cervical degeneration underwent initial PCF from 2010 through the third quarter of 2020 using the MSpine subset of the PearlDiver Patient Record Database. The incidence of perioperative complications was queried using relevant ICD-9, 10, and CPT codes. χ 2 analysis was performed in age-, sex-, and Charlson Comorbidity Index (CCI)-matched populations to compare between non-HLD and HLD patients in each single-level and multilevel PCF., Results: Through propensity score matching, 1600 patients each in the HLD and non-HLD groups were analyzed in the single-level PCF, 6855 patients were analyzed in the multilevel PCF were analyzed. The comorbidity of HLD significantly decreased the incidence of respiratory failure in single-level PCF (OR=0.58, P <0.01). In the multilevel PCF, the presence of HLD increased the incidence of cervicalgia (OR=1.26, P =0.030). On the contrary, the incident of spinal cord injury (OR=0.72, P <0.01), dysphagia (OR=0.81, P =0.023), respiratory failure (OR=0.85, P =0.030), pneumonia (OR=0.70, P =0.045), neurological bladder (OR=0.84, P =0.041), and urinary tract infection (OR=0.85, P =0.021) in the HLD group were significantly lower than those in non-HLD group., Conclusions: In the current study, the presence of HLD significantly increased the incidence of postoperative cervicalgia in multilevel PCF. On the other hand, the incidence of some complications was significantly decreased with HLD. Further studies are needed taking into account other factors such as the treatment of HLD, its efficacy, and intraoperative events., Level of Evidence: Level III., Competing Interests: Disclosures outside of submitted work: J.C.W.- royalties: SeaSpine, Depuy, Zimmer; consulting - Precision OS (no money paid); expert testimony; AO Foundation Board (honorarium), National Spine Health Foundation (volunteer); stocks/personal investment: PearlDiver, Bone Biologics, Surgitech; Fellowship Funding (paid to institution): AO Foundation. Z.B. – Grants/ Research support: AO Spine (co-PI on a AOSpine Knowledge Forum grant, Paid directly to institution/employer); Nexus Spine (Paid directly to institution/employer), Medical Metrics (Paid directly to institution/employer); MiMedx (past, Paid directly to institution/employer), SBIR NIH (past, Paid directly to institution/employer); Medical Metrics (past, Paid directly to institution/employer); Next Science (past, Paid directly to institution/employer); Consultancy: Next Science (paid directly to institution/employer); NIH (advisor consultant); Scientific Advisory Board: Medtronic, Medical Metrics; Trips/Travel: AO Spine (Travel Expense Reimbursement, travel reimbursements for AO Spine Knowledge forum meetings and congresses), NASS (Travel Expense Reimbursement); Board of Directors: LSRS (Nonfinancial, Co-chair of Program Committee); Committees: AO Spine Knowledge Forum Degenerative (Steering Committee Member); North American Spine Society: Research Project Management Committee (Vice chair), Section on Biologics & Basic Research (Co-chair), The Spine Journal Peer Reviewers (Committee member). Patents (issued): Biomarkers for painful intervertebral discs and methods of use thereof, the remaining authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Competing Interests: The authors report no conflicts of interest.

Purpose: Current decision-making in multilevel cervical fusion weighs the potential to protect adjacent levels and reduce reoperation risk by crossing the cervicothoracic junction (C7/T1) against increased operative time and risk of complication. Careful planning is required, and the planned distal and adjacent levels should be assessed for degenerative disc disease (DDD). This study assessed whether DDD at the cervicothoracic junction was associated with DDD, disc height, translational motion, or angular variation in the adjacent superior (C6/C7) or inferior (T1/T2) levels., Methods: This study retrospectively analyzed 93 cases with kinematic MRI. Cases were randomly selected from a database with inclusion criteria being no prior spine surgery and images having sufficient quality for analysis. DDD was assessed using Pfirrmann classification. Vertebral body bone marrow lesions were assessed using Modic changes. Disc height was measured at the mid-disc in neutral and extension. Translational motion and angular variation were calculated by assessing translational or angular motion segment integrity respectively in flexion and extension. Statistical associations were assessed with scatterplots and Kendall's tau., Results: DDD at C7/T1 was positively associated with DDD at C6/C7 (tau = 0.53, p < 0.01) and T1/T2 (tau = 0.58, p < 0.01), with greater disc height in neutral position at T1/T2 (tau = 0.22, p < 0.01), and with greater disc height in extended position at C7/T1 (tau = 0.17, p = 0.04) and at T1/T2 (tau = 0.21, p < 0.01). DDD at C7/T1 was negatively associated with angular variation at C6/C7 (tau = - 0.23, p < 0.01). No association was appreciated between DDD at C7/T1 and translational motion., Conclusion: The association of DDD at the cervicothoracic junction with DDD at the adjacent levels emphasizes the necessity for careful selection of the distal level in multilevel fusion in the distal cervical spine., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To describe the incidence of complications associated with cervical spine surgery and post-operative physical therapy (PT), and to identify if the timing of initiation of post-operative PT impacts the incidence rates., Methods: MOrtho PearlDiver database was queried using billing codes to identify patients who had undergone Anterior Cervical Discectomy and Fusion (ACDF), Posterior Cervical Fusion (PCF), or Cervical Foraminotomy and post-operative PT from 2010-2019. For each surgical procedure, patients were divided into three 12-week increments for post-operative PT (starting at post-operative weeks 2, 8, 12) and then matched based upon age, gender, and Charlson Comorbidity Index score. Each group was queried to determine complication rates and chi-square analysis with adjusted odds ratios, 95% confidence intervals, and p-values were used., Results: Following matching, 3,609 patients who underwent cervical spine surgery at one or more levels and had post-operative PT (ACDF:1784, PCF:1593, and cervical foraminotomy:232). The most frequent complications were new onset cervicalgia (2-14 weeks, 8-20 weeks, 12-24 weeks): ACDF (15.0%, 14.0%, 13.0%), PCF (18.8%, 18.0%, 19.9%), cervical foraminotomy (16.8%, 16.4%, 19.4%); revision: ADCF (7.9%, 8.2%, 7.4%), PCF (9.3%, 10.6%, 10.2%), cervical foraminotomy (11.6%, 10.8% and 13.4%); wound infection: ACDF (3.3%, 3.4%, 3.1%), PCF (8.3%, 8.0%,7.7%), cervical foraminotomy (5.2%, 6.5%, < 4.7%). None of the comparisons were statistically significant., Conclusion: The most common post-operative complications included new onset cervicalgia, revision and wound infection. Complications rates were not impacted by the timing of initiation of PT whether at 2, 8, or 12 weeks post-operatively., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The aim of the current review is to summarize the current evidence on graft materials used in fusion procedures for spinal deformity corrections., Methods: PubMed, Embase, and Cochrane Library were searched for relevant published observational studies and clinical trials using osteobiologics and biomaterials in spinal deformity surgery., Results: The use of autograft in deformity correction surgeries has been reported in a limited number of studies, with the harvest sites including iliac crest, ribs, and local bone. Various allografts and biologics have been used in the treatment of spinal deformities including idiopathic and degenerative scoliosis, either as stand alone or in combination with autograft. Limited number of studies reported no differences in fusion rates or outcomes. Use of rh-BMP2 in anterior, posterior or front/back approaches showed higher fusion rates than other graft materials in patients with spinal deformities. Due to the limited number of quality studies included in the review, as well as alternative factors, such as costs, availability, and surgeon expertise/preference, no definitive conclusion or recommendations can be made as to the ideal graft choice in spinal deformity surgery., Conclusions: Most commonly used grafts included autograft, allograft and rh-BMP2, with new biologics and biomaterials constantly emerging in the market. Limited number of high-quality comparative studies and heterogeneity in study design prevented direct comparisons that can lead to meaningful recommendations. Further studies are needed to prove superiority of any single graft material and/or biologic that is also cost-effective and safe., (© 2022. The Author(s), under exclusive licence to Scoliosis Research Society.)

Purpose: Lumbar fusion is widely used to treat degenerative and traumatic conditions of the spine, with various perioperative complications. This study compared lumbar fusion complications in patients with and without chronic hyperlipidemia., Methods: Using the MSpine division of the PearlDiver database, patients with or without chronic hyperlipidemia who underwent lumbar fusions were identified. The appropriate Current Procedural Terminology (CPT) codes identified patients with single- or multi-level lumbar spinal fusion surgeries. International Classification of Diseases (ICD-9 and ICD-10) codes identified patients with chronic hyperlipidemia. The surgical and medical complications were obtained utilizing the appropriate ICD-9, ICD-10, and CPT codes. Propensity score matching analysis was used to control for confounding factors. Chi-square test was applied to compare the incidence of complications among different groups., Results: In single-level fusion group, patients with hyperlipidemia had a higher incidence of wound complications (P < 0.001), surgical site infection (P < 0.001), failed back syndrome (P < 0.001), hardware removal (P < 0.001), deep venous thrombosis/pulmonary embolism (P = 0.031), myocardial infarction (P < 0.001) cerebrovascular accident (P < 0.001), renal failure (P < 0.001), sepsis (P < 0.001), and urinary tract infection/incontinence (P < 0.001). In multi-level fusion group, patients with hyperlipidemia had a higher incidence of nerve root injury (P = 0.034), wound complications (P < 0.001), surgical site infection (P < 0.001), failed back syndrome (P < 0.001), hardware removal (P < 0.001), revision (P = 0.002), myocardial infarction (P < 0.001), renal failure (P < 0.001), and urinary tract infection/incontinence (P < 0.001)., Conclusion: Following lumbar fusion, patients with chronic hyperlipidemia have an increased risk of perioperative complications, including wound complications, surgical site infection, failed back surgery syndrome, hardware removal, myocardial infarction, renal failure, and urinary tract infection/incontinence., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Study Design: Retrospective Cohort Study., Purpose: This study evaluates the impact of patient frailty status on postoperative complications in those undergoing multi-level lumbar fusion surgery., Methods: The Nationwide Readmission Database (NRD) was retrospectively queried between 2016 and 2017 for patients receiving multi-level lumbar fusion surgery. Demographics, frailty status, and relevant complications were queried at index admission and readmission intervals. Primary outcome measures included perioperative complications and 30-, 90-, and 180-day complication and readmission rates. Perioperative complications of interest were infection, urinary tract infection (UTI), and posthemorrhagic anemia. Secondary outcome measures included inpatient length of stay (LOS), adjusted all-payer costs, and discharge disposition. Nearest-neighbor propensity score matching for demographics was implemented to identify non-frail patients with similar diagnoses and procedures. Subgroup analysis of minimally invasive surgery (MIS) versus open surgery within frail and non-frail cohorts was conducted to evaluate differences in surgical and medical complication rates. The analysis used nonparametric Mann-Whitney U testing and odds ratios., Results: Frail patients encountered higher rates perioperative complications including posthemorrhagic anemia (OR: 1.73, 95%CI 1.50-2.00, p < 0.0001), infection (OR: 2.94, 95%CI 2.04-4.36, p < 0.0001), UTI (OR: 2.57, 95%CI 2.04-3.26, p < 0.0001), and higher rates of non-routine discharge (OR: 2.07, 95%CI 1.80-2.38, p < 0.0001). Frail patients had significantly greater LOS and total all-payer inpatient costs compared to non-frail patients (p < 0.0001). Frailty was associated with significantly higher rates of 90- (OR: 1.43, 95%CI 1.18-1.74, p = 0.0003) and 180-day (OR: 1.28, 95%CI 1.03-1.60, p = 0.02) readmissions along with higher rates of wound dehiscence (OR: 2.21, 95%CI 1.17-4.44, p = 0.02) at 90 days. Subgroup analysis revealed that frail patients were at significantly higher risk for surgical complications with open surgery (16%) compared to MIS (0%, p < 0.0001). No significant differences were found between surgical approaches with respect to medical complications in both cohorts, nor surgical complications in non-frail patients., Conclusions: Frailty was associated with higher odds of all perioperative complications, LOS, and all-payer costs following multi-level lumbar fusion. Frail patients had significantly higher rates of 90 and 180-day readmission and higher rates of wound disruption at 90-days. On subgroup analysis, MIS was associated with significantly reduced rates of surgical complications specifically in frail patients. Our results suggest frailty status to be an important predictor of perioperative complications and long-term readmissions in geriatric patients receiving multi-level lumbar fusions. Frail patients should undergo surgery utilizing minimally invasive techniques to minimize risk of surgical complications. Future studies should explore the utility of implementing frailty in risk stratification assessments for patients undergoing spine surgery., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background Context: Adjacent segment disease (ASD) is a potential complication following lumbar spinal fusion., Purpose: This study aimed to demonstrate the demographic, clinical, and operative risk factors associated with ASD development following lumbar fusion., Study Design/setting: Systematic review and meta-analysis., Patient Sample: We identified 35 studies that reported risk factors for ASD, with a total number of 7,374 patients who had lumbar spine fusion., Outcome Measures: We investigated the demographic, clinical, and operative risk factors for ASD after lumbar fusion., Methods: A literature search was done using PubMed, Embase, Medline, Scopus, and the Cochrane library databases from inception to December 2019. The methodological index for non-randomized studies (MINORS) criteria was used to assess the methodological quality of the included studies. A meta-analysis was done to calculate the odds ratio (OR) with the 95% confidence interval (CI) for dichotomous data and mean difference (MD) with 95% CI for continuous data., Results: Thirty-five studies were included in the qualitative analysis, and 22 studies were included in the meta-analyses. The mean quality score based on the MINORS criteria was 12.4±1.9 (range, 8-16) points. Significant risk factors included higher preoperative body mass index (BMI) (mean difference [MD]=1.97 kg/m 2 ; 95% confidence interval [CI]=1.49-2.45; p<.001), floating fusion (Odds ratio [OR]=1.78; 95% CI=1.32-2.41; p<.001), superior facet joint violation (OR=10.43; 95% CI=6.4-17.01; p<.001), and decompression outside fusion construct (OR=1.72; 95% CI=1.25-2.37; p<.001)., Conclusions: The overall level of evidence was low to very low. Higher preoperative BMI, floating fusion, superior facet joint violation, and decompression outside fusion construct are significant risk factors of development of ASD following lumbar fusion surgeries., Competing Interests: Declaration of competing interests The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background Context: The concept of frailty has become increasingly recognized, and while patients with cancer are at increased risk for frailty, its influence on perioperative outcomes in metastatic spine tumors is uncertain. Furthermore, the impact of frailty can be confounded by comorbidities or metastatic disease burden., Purpose: The purpose of this study was to evaluate the influence of frailty and comorbidities on adverse outcomes in the surgical management of metastatic spine disease., Study Design/setting: Retrospective analysis of a nationwide database to include patients undergoing spinal fusion for metastatic spine disease., Patient Sample: A total of 1,974 frail patients who received spinal fusion with spinal metastasis, and 1,975 propensity score matched non-frail patients., Outcome Measures: Outcomes analyzed included mortality, complications, length of stay (LOS), nonroutine discharges and costs., Methods: A validated binary frailty index (Johns Hopkins Adjusted Clinical Groups) was used to identify frail and non-frail groups, and propensity score-matched analysis (including demographics, comorbidities, surgical and tumor characteristics) was performed. Sub-group analysis of levels involved was performed for cervical, thoracic, lumbar and junctional spine. Multivariable-regression techniques were used to develop predictive models for outcomes using frailty and the Elixhauser Comorbidity Index (ECI)., Results: 7,772 patients underwent spinal fusion with spinal metastasis, of which 1,974 (25.4%) patients were identified as frail. Following propensity score matching for frail (n=1,974) and not-frail (n=1,975) groups, frailty demonstrated significantly greater medical complications (OR=1.58; 95% CI 1.33-1.86), surgical complications (OR=1.46; 95% CI 1.15-1.85), LOS (OR=2.65; 95% CI 2.09-3.37), nonroutine discharges (OR=1.79; 95% CI 1.46-2.20) and costs (OR=1.68; 95% CI 1.32-2.14). Differences in mortality were only observed in subgroup analysis and were greater in frail junctional and lumbar spine subgroups. Models using ECI alone (AUC=0.636-0.788) demonstrated greater predictive ability compared to those using frailty alone (AUC=0.633-0.752). However, frailty combined with ECI improved the prediction of increased LOS (AUC=0.811), cost (AUC=0.768), medical complications (AUC=0.723) and nonroutine discharges (AUC=0.718). Predictive modeling of frailty in subgroups demonstrated the greatest performance for mortality (AUC=0.750) in the lumbar spine, otherwise performed similarly for LOS, costs, complications, and discharge across subgroups., Conclusions: A high prevalence of frailty existed in the current patient cohort. Frailty contributed to worse short-term adverse outcomes and could be more influential in the lumbar and junctional spine due to higher risk of deconditioning in the postoperative period. Predictions for short term outcomes can be improved by adding frailty to comorbidity indices, suggesting a more comprehensive preoperative risk stratification should include frailty., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: Anterior thoracolumbar (TL) surgical approaches provide more direct trajectories compared to posterior approaches. Proper patient selection is key in identifying populations that may benefit from anterior TL fusion. Here, we utilize predictive analytics to identify risk factors in anterior TL fusion in patients with trauma and deformity., Methods: In this retrospective cohort study of patients receiving anterior TL fusion (between and including T12/L1), population-based regression models were developed to identify risk factors using the National Readmission Database 2016-2017. Readmissions were analyzed at 30- and 90-day intervals. Risk factors included hypertension, obesity, malnutrition, smoking, alcohol use, long-term opioid use, and frailty. Multivariate regression models were developed to determine the influence of each risk factor on complication rates., Results: A total of 265 and 375 patients were identified for the scoliosis and burst fracture cohorts, respectively. In patients with scoliosis, alcohol use was found to increase the length of stay (LOS) (p = 0.00061) and all-payer inpatient cost following surgery (p = 0.014), and frailty was found to increase the inpatient LOS (p = 0.0045). In patients with burst fractures, malnutrition was found to increase the LOS (p < 0.0001) and all-payer cost (p < 0.0001), obesity was found to increase the all-payer cost (p = 0.012), and frailty was found to increase the all-payer cost (p = 0.031) and LOS (p < 0.0001)., Discussion: Patient-specific risk factors in anterior TL fusion surgery significantly influence complication rates. An understanding of relevant risk factors before surgery may facilitate preoperative patient selection and postoperative patient triage and risk categorization., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Two main surgical approaches are available for fusing the sacroiliac joint (SIJ): an open or minimally invasive (MIS) approach. The purpose of this study was to analyze the associated total hospital charges and postoperative complications of the MIS and open approach., Methods: Using the 2016 and 2017 National Readmission Database, we conducted a retrospective cohort analysis of 2521 patients who received a SIJ fusion with an open (N = 1990) or MIS (N = 531) approach for diagnosed sacrum pain, sacroiliitis, sacral instability, or spondylosis. Each cohort was analyzed for postoperative complications., Results: We identified 604 patients diagnosed with sacrum pain, 1142 with sacroiliitis, 315 with spondylosis, and 288 with sacral instability. Patients who received the open approach for sacrum pain had significantly higher rates of novel post-procedural pain (p = 0.045) and novel lumbar pathology (p = 0.015) within 30 days. On 30-day follow-up, patients with sacroiliitis treated with open SIJ fusion had significantly higher rates of novel postprocedural pain compared to those treated with MIS fusion (p = 0.045). Patients who received the open approach for spondylosis resulted in significantly higher rates of non-elective readmission within 30 days compared to the MIS approach (p < 0.0001). In addition, the open technique for spondylosis resulted in significantly higher rates of non-elective readmissions for infection within 30 days (p = 0.014). On 30-day follow-up, patients with sacral instability treated with open SIJ fusion had significantly higher rates of UTI (p = 0.045)., Conclusion: Our study suggests that there exist unique postoperative complications that arise after SIJ fusion specific to preoperative diagnosis and surgical approach., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Study Design: This is a retrospective cohort study of consecutive patients undergoing lumbar spinal fusion (LSF) within the PearlDiver Humana research database from 2010 to 2018., Objective: The aim of this study was to determine if timing of total hip arthroplasty (THA) affects LSF outcomes., Summary of Background Data: In patients with both spine and hip pathology, outcomes of THA have been shown to be affected by the timing of THA relative to LSF. However, few studies have assessed postoperative outcomes following LSF in this clinical scenario., Materials and Methods: A national database was queried for patients undergoing lumbar fusion and divided into 4 groups: (1) those who underwent LSF without THA (No THA); (2) those who underwent THA at least 2 years before LSF (>2 Prior THA); (3) those who underwent THA in the 2 years before LSF (0-2 Prior THA); and (4) those who underwent THA after LSF (THA After). We assessed lumbar-specific outcomes, including pseudarthrosis, revision, mechanical failure, and adjacent segment disease (ASD); as well as systemic complications. Controlling for age, sex, and Charlson comorbidity index, complication rates between all groups were assessed using univariate and multivariate logistic regression analysis. Post hoc comparisons were performed using the Fisher exact test with Bonferroni correction to account for multiple pairwise comparisons, resulting in an adjusted threshold for statistical significance of P<0.007., Results: When compared with the no THA group, those in the THA After group had a higher rate of ASD on multivariate analysis [adjusted odds ratio: 1.53, 95% confidence interval: 1.20-1.94, P<0.001]. When compared with all patients who underwent THA before LSF, patients who underwent THA after LSF had an increased risk of ASD (adjusted odds ratio: 3.80, 95% confidence interval: 2.21-6.98, P<0.001)., Conclusions: Patients who undergo THA after LSF have an increased rate of lumbar-related complications both when compared with patients who do not undergo THA and when compared with patients who undergo THA before LSF., Competing Interests: J.C.W. receives royalties for Biomet, Seaspine, and Synthes; he has investments/options in Bone Biologics, Pearldiver, Electrocore, and Surgitech; he serves on the board of directors for the AO Foundation, Society for Brain Mapping and Therapeutics, and American Orthopaedic Association; he serves on the editorial board for Spine, The Spine Journal, Clinical Spine Surgery, and Global Spine Journal; he receives fellowship funding (paid to institution) from the AO Foundation. N.D.H. is a paid consultant for MicroPort Orthopedics and Intellijoint Surgical and has stock options in Intellijoint Surgical; he serves as a board member for the American Academy of Orthopaedic Surgeons. R.J.H. is a paid consultant for Nuvasive; he serves on the editorial board for The Spine Journal, Clinical Spine Surgery, and Global Spine Journal. The remaining authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: This study was a retrospective cohort database study which looked at the relationship between myocardial reinfarction following lumbar spine surgery., Objective: Current study aimed to determine the risk of reinfarction associated with the time between initial myocardial infarction (MI) and lumbar spine surgery, type of lumbar surgical procedure, and other risk factors., Summary of Background Info: Several studies have demonstrated a strong temporal pattern between postoperative reinfarction rate and the period between previous MI and surgery. To the best of our knowledge, no study has looked specifically at the temporal relationship between previous MI, lumbar spine surgery and incidence of postoperative myocardial reinfarction., Materials and Methods: The Humana database was analyzed from Q1 2007 through Q3 2016 and the Medicare database was analyzed from Q1 2005 through Q4 2014. Patients were placed into 1 of 5 groups based on time between MI and surgery: 0-3, 4-6, 7-12, 13-24, and 25+ months. Reinfarction rates were determined in these groups. Age, sex, and type of surgery were analyzed to determine association with postoperative reinfarction rates., Results: There was a strong correlation between postoperative myocardial reinfarction and lumbar spine surgery occurring 0-3 months after the patient's initial MI (P<0.01). Those patients had a risk ratio >3 (P<0.01) compared with patients who underwent lumbar spine surgery after an interval >3 months between initial MI and lumbar spine surgery. In addition, spinal fusion procedures were associated with a greater risk of postoperative myocardial reinfarction than nonfusion procedures., Conclusion: In both databases, there was a clinically relevant and statistically significant increase in myocardial reinfarction in patients who experienced an MI 0-3 months before lumbar spine surgery. We believe that the current study helps in treatment planning for patients with a history of MI who are considering spine surgery., Level of Evidence: Level III., Competing Interests: J.C.W.: Royalties—Biomet, Seaspine, Amedica, DePuy Synthes; Investments/Options—Bone Biologics, Pearldiver, Electrocore, Surgitech; Board of Directors—North American Spine Society, AO Foundation (20,000 honorariums for board position, plus travel for board meetings), Cervical Spine Research Society; Editorial Boards—Spine, The Spine Journal, Clinical Spine Surgery, Global Spine Journal; Fellowship funding (paid directly to institution): AO Foundation. Z.B.: Consultancy: Cerapedics, The Scripps Research Institute, Xenco Medical (past), AO Spine (past); Research support: SeaSpine (past, paid to the institution), Next Science (paid directly to institution), Motion Metrics (paid directly to institution); North American Spine Society: committee member; Lumbar Spine Society: Co-chair Research committee, AOSpine Knowledge Forum Degenerative: Associate member; AOSNA Research committee–committee member. The remaining authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: Retrospective cohort study., Objective: The aim of this study was to compare different aspects of fusion surgery in patients with osteoporosis with regard to graft subtype and surgical approach., Summary of Background Data: Osteoporosis and chronic lower back pain are common in elderly populations and significantly increase the risk of compression fractures within the spine., Methods: Using the 2016-2017 National Readmission Database we identified 11,086 osteoporotic patients who received lumbar fusion using ICD-10 coding. Information regarding biologic graft type and surgical approach was collected. Patients were stratified by number of levels fused. Perioperative complications were collected at 30-, 90-, and 180-day follow-up intervals. Statistical analysis included univariate testing and multivariate regression modeling, controlling for patient demographics and comorbidities., Results: Patients receiving single-level fusion with autologous grafts had higher rates of hardware failure (P = 0.00014) at 30-day follow-up and 90-day follow-up (P < 0.0001) and higher rates of lumbar vertebral fractures at 90-day follow-up (P = 0.045) compared to those treated with nonautologous grafts. Patients receiving lumbar fusion with anterior and posterior approaches had no difference in readmission or infection rates, but the anterior approach was associated with a higher cost., Conclusion: In this study, osteoporotic patients treated with autologous grafts had higher rates of complications compared to those treated with nonautologous grafts. Anterior and posterior approaches had similar complication rates; however, the anterior approach was associated with a higher total cost.Level of Evidence: 4., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: This was a retrospective database study., Objective: The objective of this study was to investigate preoperative risk factors and incidence of venous thromboembolic events (VTEs) after cervical spine surgery., Summary of Background Data: VTEs are preventable complications that may occur after spinal procedures. Globally, VTEs account for a major cause of morbidity and mortality. Preoperative risks factors associated with increased VTE incidence after cervical spine surgery have not been well-characterized., Materials and Methods: Patients undergoing anterior cervical discectomy and fusion (ACDF); posterior cervical fusion (PCF); discectomy; and decompression from 2007 to 2017 were identified using the PearlDiver Database. International Classification of Diseases (ICD) Ninth and 10th Revision codes were used to identify VTEs at 1 week, 1 month, and 3 months postoperative as well as preoperative risk factors., Results: Risk factors with the highest incidence of VTE at 3 months were primary coagulation disorder [ACDF=7.82%, odds ratio (OR)=3.96; decompression=11.24%, OR=3.03], central venous line (ACDF=5.68%, OR=2.11; PCF=12.58%, OR=2.27; decompression=10.17%, OR=2.80) and extremity paralysis (ACDF=6.59%, OR=2.73; PCF=18.80%, OR=2.99; decompression=11.86, OR=3.74). VTE incidence at 3 months for populations with these risks was significant for all surgery types (P<0.001) with the exception of patients with primary coagulation disorder who underwent PCF. Tobacco use had the lowest VTE incidence for all surgery types., Conclusions: The total cumulative incidence of VTEs at 3-month follow-up was 3.10%, with the highest incidence of VTEs occurring within the first postoperative week (0.65% at 1 wk, 0.61% at 1 mo, 0.53% at 3 mo for ACDF; 2.56% at 1 wk, 1.93% at 1 mo, 1.45% at 3 mo for PCF; 1.37% at 1 wk, 0.93% at 1 mo, 0.91% at 3 mo for decompression). Several preoperative risk factors were found to be significant predictors for postoperative VTEs and can be used to suggest those at increased risk as well as decrease the incidence of preventable VTEs after cervical spine surgery., Level of Evidence: Level III., Competing Interests: J.W. received royalties from Biomet, Seaspine, Amedica, DePuy Synthes; investments/options from Bone Biologics, Pearldiver, Electrocore, Surgitech; was one of the Board of Directors in North American Spine Society, AO Foundation, Cervical Spine Research Society, Society for Brain Mapping and Therapeutics; serves in editorial boards at Spine, The Spine Journal, Clinical Spine Surgery, Global Spine Journal; Fellowship Funding (paid directly to institution): AO Foundation. Z.B. serves in consultancy at Cerapedics (past), The Scripps Research Institute, Xenco Medical (past), AOSpine (past); received research support from SeaSpine (past, paid to the institution), Next Science (paid directly to institution), Motion Metrics (paid directly to institution); was a committee member at North American Spine Society; is a co-chair research committee member at Lumbar Spine Society, was an associate member at AOSpine Knowledge Forum Degenerative; committee member at AOSNA research committee. J.C.L. serves in consulting at Viseon. The remaining authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: This was a retrospective cohort study., Objective: The aim of this study was to compare the hospital charges and postoperative complications of minimally invasive surgery (MIS) and open approaches to sacroiliac joint (SIJ) fusion., Summary of Background Data: The data source utilized in this study is the Healthcare Cost and Utilization Project National Readmission Database (NRD) from 2016 and 2017. The NRD is a yearly nationally representative inpatient database from the Agency for Healthcare Research and Quality with information regarding patient demographics, diagnoses, procedures, and readmissions., Materials and Methods: The 2016-2017 NRD was used to identify 2521 patients receiving SIJ fusion with open (n=1990) or MIS approaches (n=531) for diagnosed sacrum pain, sacroiliitis, sacral instability, or spondylosis after excluding for those who received prior SIJ fusion, those diagnosed with neoplasms or trauma of the pelvis or sacrum, and nonelective procedures. We then one-to-one propensity-matched the open (n=531) to the MIS approach (n=531) for age, sex, and Charlson Comorbidity Index. Statistical analysis was performed to compare total hospital charges, immediate surgical complications, nonelective readmission rate, and 30-, 90-, and 180-day postoperative complications between the 2 approaches., Results: The mean total hospital charge was the only significant difference between 2 group. Open SIJ fusion had significantly higher charge compared with the MIS approach (open $101,061.90±$81,136.67; MIS $83,594.78±$49,086.00, P<0.0001). The open approach was associated with nonsignificant higher rates of novel lumbar pathology at 30-, 90-, and 180-day readmissions and revision surgeries at 30 and 180 days. MIS approach had higher rates nervous system complications at 30-, 90-, and 180-day readmission, as well as infection and urinary tract infection within 30 days, none being significant. Novel postprocedural pain was similar between the 2 groups at 90 and 180 days., Conclusions: The current study found that open SIJ fusion was associated with significantly higher hospital charges. Although no significant differences in postoperative complications were found, there were several notable trends specific to each surgical approach., Competing Interests: Z.B.: consultancy: Cerapedics (past), Xenco Medical (past), AO Spine (past); Research Support: SeaSpine (past, paid to the institution), Next Science (paid directly to institution), Motion Metrics (paid directly to institution); North American Spine Society: committee member; Lumbar Spine Society: Co-chair Education committee, AO Spine Knowledge Forum Degenerative: Associate member; AOSNA Research committee-committee member. J.C.W.: Royalties—Biomet, Seaspine, DePuy Synthes; Investments/Options—Bone Biologics, Pearldiver, Electrocore, Surgitech; Board of Directors—AO Foundation Society for Brain Mapping and Therapeutics, American Orthopaedic Association; Editorial Boards—Spine, The Spine Journal, Clinical Spine Surgery, Global Spine Journal; Fellowship Funding (paid directly to institution): AO Foundation. The remaining authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background Context: High quality evidence is difficult to generate, leaving substantial knowledge gaps in the treatment of spinal conditions. Appropriate use criteria (AUC) are a means of determining appropriate recommendations when high quality evidence is lacking., Purpose: Define appropriate use criteria (AUC) of cervical fusion for treatment of degenerative conditions of the cervical spine., Study Design/setting: Appropriate use criteria for cervical fusion were developed using the RAND/UCLA appropriateness methodology. Following development of clinical guidelines and scenario writing, a one-day workshop was held with a multidisciplinary group of 14 raters, all considered thought leaders in their respective fields, to determine final ratings for cervical fusion appropriateness for various clinical situations., Outcome Measures: Final rating for cervical fusion recommendation as either "Appropriate," "Uncertain" or "Rarely Appropriate" based on the median final rating among the raters., Methods: Inclusion criteria for scenarios included patients aged 18 to 80 with degenerative conditions of the cervical spine. Key modifiers were defined and combined to develop a matrix of clinical scenarios. The median score among the raters was used to determine the final rating for each scenario. The final rating was compared between modifier levels. Spearman's rank correlation between each modifier and the final rating was determined. A multivariable ordinal regression model was fit to determine the adjusted odds of an "Appropriate" final rating while adjusting for radiographic diagnosis, number of levels and symptom type. Three decision trees were developed using decision tree classification models and variable importance for each tree was computed., Results: Of the 263 scenarios, 47 (17.9 %) were rated as rarely appropriate, 66 (25%) as uncertain and 150 (57%) were rated as appropriate. Symptom type was the modifier most strongly correlated with the final rating (adjusted ρ2 = 0.58, p<.01). A multivariable ordinal regression adjusting for symptom type, diagnosis, and number of levels and showed high discriminative ability (C statistic = 0.90) and the adjusted odds ratio (aOR) of receiving a final rating of "Appropriate" was highest for myelopathy (aOR, 7.1) and radiculopathy (aOR, 4.8). Three decision tree models showed that symptom type and radiographic diagnosis had the highest variable importance., Conclusions: Appropriate use criteria for cervical fusion in the setting of cervical degenerative disorders were developed. Symptom type was most strongly correlated with final rating. Myelopathy or radiculopathy were most strongly associated with an "Appropriate" rating, while axial pain without stenosis was most associated with "Rarely Appropriate.", (Copyright © 2021 Elsevier Inc. All rights reserved.)

Study Design: Retrospective cohort study using the 2013-2017 National Readmission Database., Objective: The aim of this study was to quantify the influence of body mass index (BMI) on complication and readmission rates following lumbar spine fusion., Summary of Background Data: Compared to controls, patients with BMI ≥35 had greater odds of readmission, infection, and wound complications following lumbar spine fusion., Methods: Patients who underwent elective lumbar spine fusion within the population-based sample were considered for inclusion. Exclusion criteria included nonelective lumbar spine fusions, malnourished, anorexic, or underweight patients, and surgical indications of trauma or neoplasm. Patients were grouped by BMI: 18.5 to 29.9 (controls), 30 to 34.9 (obesity I), 35 to 39.9 (obesity II), and ≥40 (obesity III). Multivariate regression was performed to analyze differences in complications and readmissions between groups. Predictive modeling was conducted to estimate the impact of BMI on 30- and 90-day infection, wound complication, and readmissions rates., Results: A total of 86,697 patients were included for analysis, with an average age of 58.9 years and 58.9% being female. The obesity II group had significantly higher odds of infection (odds ratio [OR]: 1.82, 95% confidence interval [CI]: 1.28-2.62, P = 0.001), wound dehiscence (OR: 3.08, 95% CI: 1.70-6.18, P = 0.0006), and 30-day readmission (OR: 1.32, 95% CI: 1.11-1.58, P = 0.002), whereas the obesity III group had significantly higher odds of acute renal failure (OR: 2.14, 95% CI: 1.20-4.06, P = 0.014), infection (OR: 2.43, 95% CI: 1.72-3.48, P < 0.0001), wound dehiscence (OR: 3.76, 95% CI: 2.08-7.51, P < 0.0001), 30-day readmission (OR: 1.62, 95% CI: 1.36-1.93, P < 0.0001), and 90-day readmission (OR: 1.53, 95% CI: 1.31-1.79, P < 0.0001) compared with controls. Predictive modeling showed cumulative increases of 6.44% in infection, 3.69% in wound dehiscence, and 1.35% in readmission within 90-days for each successive BMI cohort., Conclusion: Progressively higher risks for infection, wound complications, and hospital readmission were found with each progressive BMI level.Level of Evidence: 3., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To elucidate the effects of bisphosphonates on complications following posterior lumbar fusion (PLF) with a large database study., Methods: The PearlDiver Patient Record Database was queried to identify adult patients who had undergone posterior lumbar fusion (PLF). Those patient cohorts were divided based on a diagnosis of osteoporosis prior to surgery and bisphosphonate usage. This yielded three groups: Osteo+Bisph+, Osteo+Bisph-, and Osteo-Bisph-. The primary outcome of the present study was revision rates at 6 months and 1 year following surgery. Incidence of postoperative complications was analyzed, and statistical analysis was conducted using Pearson chi-square analysis., Results: Patients taking bisphosphonates did not have significantly different rates of revision surgery at 6 months and 1 year, instrumentation complications, or post-vertebral fractures than patients not taking bisphosphonates. Additionally, osteoporotic patients did not have significantly different rates of these complications than patients without osteoporosis., Conclusion: Bisphosphonate usage did not significantly affect the rates of postoperative complications following posterior lumbar fusion. Further research is required to fully elucidate the effects of bisphosphonates on outcomes and complications following spine surgery.

Level of Evidence: 3., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Despite the extensive use of cellular bone matrices (CBMs) in spine surgery, there is little evidence to support the contribution of cells within CBMs to bone formation. The objective of this study was to determine the contribution of cells to spinal fusion by direct comparisons among viable CBMs, devitalized CBMs, and cell-free demineralized bone matrix (DBM)., Methods: Three commercially available grafts were tested: a CBM containing particulate DBM (CBM-particulate), a CBM containing DBM fibers (CBM-fiber), and a cell-free product with DBM fibers only (DBM-fiber). CBMs were used in viable states (CBM-particulatev and CBM-fiberv) and devitalized (lyophilized) states (CBM-particulated and CBM-fiberd), resulting in 5 groups. Viable cell counts and bone morphogenetic protein-2 (BMP-2) content on enzyme-linked immunosorbent assay (ELISA) within each graft material were measured. A single-level posterolateral lumbar fusion was performed on 45 athymic rats with 3 lots of each product implanted into 9 animals per group. After 6 weeks, fusion was assessed using manual palpation, micro-computed tomography (μ-CT), and histological analysis., Results: The 2 groups with viable cells were comparable with respect to cell counts, and pairwise comparisons showed no significant differences in BMP-2 content across the 5 groups. Manual palpation demonstrated fusion rates of 9 of 9 in the DBM-fiber specimens, 9 of 9 in the CBM-fiberd specimens, 8 of 9 in the CBM-fiberv specimens, and 0 of 9 in both CBM-particulate groups. The μ-CT maturity grade was significantly higher in the DBM-fiber group (2.78 ± 0.55) compared with the other groups (p < 0.0001), while none of the CBM-particulate samples demonstrated intertransverse fusion in qualitative assessments. The viable and devitalized samples in each CBM group were comparable with regard to fusion rates, bone volume fraction, μ-CT maturity grade, and histological features., Conclusions: The cellular component of 2 commercially available CBMs yielded no additional benefits in terms of spinal fusion. Meanwhile, the groups with a fiber-based DBM demonstrated significantly higher fusion outcomes compared with the CBM groups with particulate DBM, indicating that the DBM component is probably the key determinant of fusion., Clinical Relevance: Data from the current study demonstrate that cells yielded no additional benefit in spinal fusion and emphasize the need for well-designed clinical studies on cellular graft materials., Competing Interests: Disclosure: This work was supported by a research grant from SeaSpine Holdings. SeaSpine manufacturers one of the products investigated in the study, and two of the authors are employees of SeaSpine. On the Disclosure of Potential Conflicts of Interest forms, which are provided with the online version of the article, one or more of the authors checked “yes” to indicate that the author had a relevant financial relationship in the biomedical arena outside the submitted work (including employment with SeaSpine Holdings) and “yes” to indicate that the author had a patent and/or copyright, planned, pending, or issued, directly relevant to this work (http://links.lww.com/JBJS/G166)., (Copyright © 2020 The Authors. Published by The Journal of Bone and Joint Surgery, Incorporated. All rights reserved.)

Study Design: A prospective multicenter study., Objective: The objective of this study was to assess bacterial contamination in current practices of pedicle screw handling and comparing it to a novel method of using an intraoperative, sterile implant guard for screws., Summary of Background Data: Postoperative infections occur at the higher end of 2%-13%, as cited in the literature, and are underestimated due to various reasons in such publications. Despite concerns associated with vancomycin application immediately before closure, it is theoretically impossible to irrigate the screw-bone interface postimplantation. Consequently, any contamination of pedicle screw before implantation is permanent, and has the potential to cause deep-bone infection, or hardware loosening due to encapsulation of biofilm between the bone and the screw. Therefore, continued vigilance and effective preventive measures should be undertaken if available., Materials and Methods: Two groups of presterile individually-packaged pedicle screws, one incased in a sterile, protective guard (group 1: G) and the other without such a guard (group 2: NG), 31 samples in each group were distributed over 28 spinal fusion surgeries at 5 independent hospitals groups. Each were loaded onto the insertion device by the scrub tech and left on the sterile table. Twenty minutes later, the lead surgeon who had just finished preparing the surgical site, handles the pedicle screw, to check the fit with the insertion device. Then, instead of implantation, it was transferred to a sterile container using fresh sterile gloves for bacterial analysis., Results: The standard unguarded pedicle screws presented bioburden in the range of 10 to 10 colonies forming units per screw, whereas the guarded pedicle screws showed no bioburden., Conclusion: Standard, current, handling of pedicle screws leads to bacterial contamination, which can be avoided if the screws are sterilely prepackaged with an intraoperative guard (preinstalled).

Background Context: Posterior cervical foraminotomy (PCF) is a relatively safe procedure for the treatment of cervical radiculopathy. Though most often performed as an inpatient procedure, there is an increasing number of patients treated in an outpatient setting., Purpose: This study aimed to compare the perioperative complication rates associated with inpatient and outpatient single-level PCF., Study Design/setting: Retrospective database study., Patient Sample: Patients with cervical radiculopathy who underwent inpatient or outpatient single-level PCF between 2007 to the first quarter of 2016., Outcome Measures: Charlson Comorbidity Index (CCI) was used as a broad measure of comorbidity. Surgical complications included cervical nerve root injury, dural tear, wound complications, infection, dysphagia, cervicalgia, and revision surgery. Medical complications included pulmonary embolism and lower limb deep vein thrombosis, acute myocardial infarction, acute respiratory failure, pneumonia, sepsis, and urinary complications., Methods: This study was a retrospective review of patients who received single-level PCF from 2007 to the first quarter of 2016 as either outpatients or inpatients using the Humana subset of the PearlDiver Patient Record Database. The incidence of perioperative medical and surgical complications was queried using relevant International Classification of Diseases (ICD-9-CM and ICD-10-CM) and Current Procedural Terminology codes. Multivariate logistic regression analysis, adjusted for age, gender, and CCI, was performed to calculate odds ratios (ORs) of complications among inpatients relative to outpatients treated with PCF. Propensity score matching was done, and comparisons were made for postoperative complications., Results: Throughout the time period, 1,469 and 1,192 patients received inpatient and outpatient single-level PCF, respectively. The mean CCIs±standard deviation of inpatient and outpatient groups undergoing PCF were 2.83±3.11 and 1.46±2.21, respectively (p<.001). After propensity score matching, patients who received PCF in an inpatient setting showed significantly higher rates of wound complications (OR=1.53, 95% confidence interval [CI]=1.04-2.23; p=.029), infection (OR=1.91, CI=1.15-3.15; p=.012), acute respiratory failure (OR=2.50, CI=1.23-5.08; p=.011), and urinary tract infections and incontinence (OR=2.11, CI=1.32-3.38; p=.002)., Conclusions: Outpatient single-level PCF was associated with a lower rate of perioperative medical and surgical complications. The PCF in the outpatient setting can potentially be a safe procedure for the treatment of cervical radiculopathy with appropriate patient selection., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Low back and neck pain are among the top contributors for years lived with disability, causing patients to seek substantial non-operative and operative care. Intervertebral disc herniation is one of the most common spinal pathologies leading to low back pain. Patient comorbidities and other risk factors contribute to the onset and magnitude of disc herniation. Spine fusions have been the treatment of choice for disc herniation, due to the conflicting evidence on conservative treatments. However, re-operation and costs have been among the main challenges. Novel technologies including cage surface modifications, biologics, and 3D printing hold a great promise. Artificial disc replacement has demonstrated reduced rates of adjacent segment degeneration, need for additional surgery, and better outcomes. Non-invasive biological approaches are focused on cell-based therapies, with data primarily from preclinical settings. High-quality comparative studies are needed to evaluate the efficacy and safety of novel technologies and biological therapies.

Background Context: Previous studies have found an association between mental illness and poor outcomes in spine surgery, but little is known about the effects of depression and/or anxiety on the adult spinal deformity population. In addition, most relevant studies exclusively focused on the lumbar spine and had relatively small patient sizes., Purpose: The aim of this study was to investigate whether adult spinal deformity patients with depression and/or anxiety have an increased risk of postoperative complications and reoperation following posterior thoracolumbar spinal surgery., Study Design/setting: Retrospective database study., Methods: Adult patients (over 18 years of age) with a diagnosis of spinal deformity undergoing any reconstructive thoracic or thoracolumbar spinal procedure with a posterior approach between 2007 and 2015 Q2 were identified using Current Procedural Terminology codes to query the Pearl Diver patient record database (Pearl Diver Technologies, West Conshohocken, PA, USA). The database includes records of approximately 18 million patients across the United States having Humana insurance. Further selection of patients with depression and/or anxiety and their associated postoperative complications were identified using ICD-9 and ICD-10 diagnosis codes (International Classification of Diseases 9th-10th edition). The mental illness cohort was matched to a control group according to age, sex, and Charlson Comorbidity Index. Patient data was analyzed for reoperation rates and incidence of common postoperative complications., Results: Multilevel posterolateral fusion was the most common included posterior thoracic reconstructive surgery. The mental illness cohort (n = 327) had significantly increased rates of infection (odds ratio [OR] = 1.743, p = .022) and respiratory complications (OR = 1.492, p = .02) at the 90-day postoperative period. The rates of incision and drainage (OR = 1.379, p = .475) and pneumonia (OR = 1.22, p = .573) were increased in the mental illness cohort at the 90-day postoperative period, but not significantly. There were no significant differences in complication and reoperation rates at 1-year postoperatively., Conclusions: Patients with spinal deformity and pre-existing depression and/or anxiety treated with a posterior thoracolumbar reconstructive spinal surgery had significantly elevated risk of postoperative infections and respiratory complications when compared with the control group., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Study Design: A retrospective case-control study., Objective: The aim of this study was to determine the nationwide trends and complication rates associated with outpatient posterior lumbar fusion (PLF)., Summary of Background Data: Outpatient lumbar spine fusion is now possible secondary to minimally invasive techniques that allow for reduced hospital stays and analgesic requirements. Limited data are currently available regarding the clinical outcome of outpatient lumbar fusion., Methods: The Humana administrative claims database was queried for patients who underwent one to two-level PLF (CPT-22612 or CPT-22633 AND ICD-9-816.2) as either outpatients or inpatients from Q1 2007 to Q2 2015. The incidence of perioperative medical and surgical complications was determined by querying for relevant International Classification of Diseases and Current Procedural Terminology codes. Multivariate logistic regression adjusting for age, gender, and Charlson Comorbidity Index was used to calculate odds ratios (ORs) of complications among outpatients relative to inpatients undergoing PLF., Results: Cohorts of 770 patients who underwent outpatient PLF and 26,826 patients who underwent inpatient PLF were identified. The median age was in the 65 to 69 years age group for both cohorts. The annual relative incidence of outpatient PLF remained stable across the study period (R = 0.03, P = 0.646). Adjusting for age, gender, and comorbidities, patients undergoing outpatient PLF had higher likelihood of revision/extension of posterior fusion [(OR 2.33, confidence interval (CI) 2.06-2.63, P < 0.001], anterior fusion (OR 1.64, CI 1.31-2.04, P < 0.001), and decompressive laminectomy (OR 2.01, CI 1.74-2.33, P < 0.001) within 1 year. Risk-adjusted rates of all other postoperative surgical and medical complications were statistically comparable., Conclusion: Outpatient lumbar fusion is uncommonly performed in the United States. Data collected from a national private insurance database demonstrate a greater risk of postoperative surgical complications including revision anterior and posterior fusion and decompressive laminectomy. Surgeons should be cautious in performing PLF in the outpatient setting, as the risk of revision surgery may increase in these cases., Level of Evidence: 3.

Background Context: With the changing landscape of health care, outpatient spine surgery is being more commonly performed to reduce cost and to improve efficiency. Anterior cervical discectomy and fusion (ACDF) is one of the most common spine surgeries performed and demand is expected to increase with an aging population., Purpose: The objective of this study was to determine the nationwide trends and relative complication rates associated with outpatient ACDF., Study Design/setting: This is a large-scale retrospective case control study., Patient Sample: The patient sample included Humana-insured patients who underwent one- to two-level ACDF as either outpatients or inpatients from 2011 to 2016 OUTCOME MEASURES: The outcome measures included incidence and the adjusted odds ratio (OR) of postoperative medical and surgical complications within 1 year of the index surgery., Materials and Methods: A retrospective review was performed of the PearlDiver Humana insurance records database to identify patients undergoing one- to two-level ACDF (Current Procedural Terminology [CPT]-22551 and International Classification of Diseases [ICD]-9-816.2) as either outpatients or inpatients from 2011 to 2016. The incidence of perioperative medical and surgical complications was determined by querying for relevant ICD and CPT codes. Multivariate logistic regression adjusting for age, gender, and Charlson Comorbidity Index was used to calculate ORs of complications among outpatients relative to inpatients undergoing ACDF., Results: Cohorts of 1,215 patients who underwent outpatient ACDF and 10,964 patients who underwent inpatient ACDF were identified. The median age was in the 65-69 age group for both cohorts. The annual relative incidence of outpatient ACDF increased from 0.11 in 2011 to 0.22 in 2016 (R 2 =0.82, p=.04). Adjusting for age, gender, and comorbidities, patients undergoing outpatient ACDF were more likely to undergo revision surgery for posterior fusion at both 6 months (OR 1.58, confidence interval [CI] 1.27-1.96, p<.001) and 1 year (OR 1.79, CI 1.51-2.13, p<.001) postoperatively. Outpatient ACDF was also associated with a higher likelihood of revision anterior fusion at 1 year postoperatively (OR 1.46, CI 1.26-1.70, p<.001). Among medical complications, postoperative acute renal failure was more frequently associated with outpatient ACDF than inpatient ACDF (OR 1.25, CI 1.06-1.49, p=.010). Adjusted rates of all other queried surgical and medical complications were comparable., Conclusions: Outpatient ACDF is increasing in frequency nationwide over the past several years. Nationwide data demonstrate a greater risk of perioperative surgical complications, including revision anterior and posterior fusion, as well as a higher risk of postoperative acute renal failure. Candidates for outpatient ACDF should be counseled and carefully selected to reduce these risks., (Published by Elsevier Inc.)

Study Design: Retrospective study., Objective: Evaluate the effect of age on the efficacy of allograft/demineralized bone matrix (DBM) enriched with concentrated bone marrow aspirate (BMA) in posterolateral lumbar fusions (PLFs)., Summary of Background Data: Cell-based therapies such as concentrated BMA have been developed as a potential alternative to iliac crest bone graft (ICBG). BMA contains mesenchymal stem cells (MSCs) and growth factors that can confer osteogenic and osteoinductive potential to osteoconductive scaffolds such as DBM/allograft. To date, no studies have examined the role of age on fusion outcomes when BMA is utilized despite the well-established deleterious effects of advanced age on bone marrow and MSC potential., Materials and Methods: Fifty-one patients that underwent PLF were divided into 3 groups. Group A (n=14) composed of patients age 65 years and older who received BMA with DBM. Group B (n=17) consisted of patients younger than 65 years of age who received BMA with DBM. Group C (n=20) composed of patients age 65 years and older who received ICBG. Fusion rates and clinical outcomes were assessed., Results: Fusion was significantly lower in group A (35.7%) compared with both groups B (76.4%) and C (80%) (A vs. B, P=0.03; A vs. C, P=0.01). There were no differences in clinical outcomes among all groups except for pseudarthrosis which occurred in 28.6% of patients in group A compared with none and 5% of patients in groups B and C, respectively (A vs. B, P=0.03; A vs. C, P=0.13)., Conclusions: Elderly patients undergoing PLF using DBM enriched with BMA achieved lower radiographic fusion success compared with their nonelderly counterparts and compared with elderly patients that had fusion with ICBG. This may be partly due to the effect of advanced age on MSC potential.

Study Design: Epidemiologic Study., Objectives: To identify the trends in utilization of outpatient discharge for single level anterior cervical discectomy and fusion (ACDF), between 2007 and 2014, and to compare the costs and incidence of complications against a cohort of inpatients., Methods: We retrospectively reviewed 18,386 patients from the PearlDiver database from between 2007 and 2014. Discharge status was determined from billing codes. The total cost of all procedures and diagnostic tests, was determined for the global period from the time of diagnosis up until 90-days post-operatively, and the incidence of complications was recorded for 30-days., Results: The proportion of outpatient discharges was stable around 20% from 2007 to 2014 (range17-23%). The mean 90-day cost was lower for outpatients ($39,528 v. $47,330) but reimbursement fell nearly 1/3 from 2007-2014 for both groups, and the difference between the two narrowed over time ($13,745 difference in 2008, to $3,834 in 2014). Outpatients had a lower incidence of overall 30-day complications (9.5% v. 18.6%, p<0.0001), but were also significantly less comorbid (mean Charlson comorbidity index 2.32 v. 3.85, p<0.001). Older patient age, obesity, cardiac, renal, and pulmonary comorbidity were each more common in the inpatients (p<0.05 for each)., Conclusions: Outpatient discharge after ACDF is a viable treatment option with a reasonable safety profile and decreased costs relative to inpatient admission. Appropriate patient selection is key, and the standard of care nationally for the comorbid patient remains inpatient admission. The economic trends and epidemiologic data presented here should be useful for health policy decisions., Competing Interests: Conflict of Interest Statement:

Purpose: The aim of our study was to determine the effect of Oxy133 and rhBMP2 on fusion rates and new bone formation in a rat posterolateral fusion (PLF) model. Furthermore, we examined whether Oxy133 could inhibit the adipogenesis that is often present in rhBMP2-induced fusions., Methods: Sixty-four male Lewis rats underwent two levels PLF (L3-L5). All animals were randomly divided into eight groups based on the test compound that they received: control (DMSO), low-dose rhBMP2 (0.5 µg), high-dose rhBMP2 (5 µg), low-dose Oxy133 (5 mg), high-dose Oxy133 (20 mg), low rhBMP2 + high Oxy133, high rhBMP2 + high Oxy133, and low rhBMP2 + low Oxy133. Fusion rates were assessed 8 weeks after surgery with manual palpation and plain radiographs. Bone parameters were measured using microCT. Histology was used to evaluate adipogenesis., Results: No fusion was observed in the control group. Based on the manual palpation, 100% fusion was observed in all other groups except in the low-dose rhBMP2 group (69%). At 8 weeks based on X-rays, 100% fusion was observed in the following groups: high-dose rhBMP2, low-dose Oxy133, and low rhBMP2 + low Oxy133. In the other groups, the fusion rates were between 95 and 97%, except for the low rhBMP2 group (72%). We observed similar values in BV/TV ratio at L3-4 when Oxy133 groups were compared to rhBMP2 groups alone (44.62% in high-dose Oxy133 vs. 41.47% in high-dose rhBMP2 and 47.18% in low-dose Oxy133 vs. 54.98% in low-dose rhBMP2). Trabecular thickness was slightly lower in Oxy133 groups compared to rhBMP2 when comparing low- and high-dose groups from each group (118.44 µm for high-dose Oxy133 vs. 122.39 µm for high-dose rhBMP2 and 123.51 µm for low-dose Oxy133 vs. 135.74 µm for low-dose rhBMP2). At the same time, trabecular separation was lower in Oxy133 groups compared to rhBMP2 groups. Similar trends in bone parameters were observed at the L4-5 levels. Fusion masses with low- and high-dose Oxy133 had significantly less adipocytes than rhBMP2 groups that showed robust adipocyte formation., Conclusion: In our study, both low-dose and high-dose Oxy133 produced solid fusions with bone densities similar or higher than in the BMP2 groups. High-dose Oxy133 group had significantly less adipocytes than high- or low-dose rhBMP2 groups. Furthermore, high-dose Oxy133 was able to significantly inhibit high-dose BMP2-induced adipogenesis when combined together. Consistent with the previous reports, our preliminary findings suggest that Oxy133 has a significant potential as an alternative to rhBMP2 in spine fusion.

Study Design: A retrospective cohort study., Objective: To compare the complications between posterior cervical fusions with and without recombinant human bone morphogenetic protein 2 (rhBMP2)., Summary of Background Data: Use of rhBMP2 in anterior cervical spinal fusion procedures can lead to potential complications such as neck edema, resulting in airway complications or neurological compression. However, there are no data on the complications associated with the "off-label" use of rhBMP2 in upper and lower posterior cervical fusion approaches., Materials and Methods: Patients from the PearlDiver database who had a posterior cervical fusion between 2005 and 2011 were identified. We evaluated complications within 90 days after fusion and data was divided in 2 groups: (1) posterior cervical fusion including upper cervical spine O-C2 (upper group) and (2) posterior cervical fusion including lower cervical spine C3-C7 (lower group). Complications were divided into: any complication, neck-related complications, wound-related complications, and other complications., Results: Of the 352 patients in the upper group, 73 patients (20.7%) received rhBMP2, and 279 patients (79.3%) did not. Likewise, in the lower group of 2372 patients, 378 patients (15.9%) had surgery with rhBMP2 and 1994 patients (84.1%) without. In the upper group, complications were observed in 7 patients (9.6%) with and 34 patients (12%) without rhBMP2. In the lower group, complications were observed in 42 patients (11%) with and 276 patients (14%) without rhBMP2. Furthermore, in the lower group the wound-related complications were significantly higher in the rhBMP2 group (23 patients, 6.1%) compared with the non-rhBMP2 group (75 patients, 3.8%)., Conclusions: Our data showed that the use of rhBMP2 does not increase the risk of complications in upper cervical spine fusion procedures. However, in the lower cervical spine, rhBMP2 may elevate the risk of wound-related complications. Overall, there were no major complications associated with the use of rhBMP2 for posterior cervical fusion approaches., Level of Evidence: Level III.

Study Design: A retrospective database study., Objective: The goal of this study was to (1) evaluate the trends in the use of electromyography (EMG) for instrumented posterolateral lumbar fusions (PLFs) in the United States and (2) assess the risk of neurological injury following PLFs with and without EMG., Summary of Background Data: Neurologic injuries from iatrogenic pedicle wall breaches during screw placement are known complications of PLFs. The routine use of intraoperative neuromonitoring (ION) such as EMG during PLF to improve the accuracy and safety of pedicle screw implantation remains controversial., Methods: A retrospective review was performed using the PearlDiver Database to identify patients who had PLF surgery with and without EMG for lumbar disorders from years 2007 to 2015. Patients undergoing concomitant interbody fusions or spinal deformity surgery were excluded. Demographic trends and risk of neurological injuries were assessed., Results: During the study period, 2007 to 2015, 9957 patients underwent PLFs. Overall, EMG was used in 2495 (25.1%) of these patients. There was a steady increase in the use of EMG from 14.9% in 2007 to 28.7% in 2009, followed by a steady decrease to 21.9% in 2015 (P < 0.0001). The risk of postoperative neurological injuries following PLFs was 1.35% (134/9957) with a risk of 1.36% (34/2495) with EMG and 1.34% (100/7462) without EMG (P = 0.932). EMG is used most commonly for PLFs in the Southern part of the United States., Conclusion: In this retrospective national database review, we found that there was a steady increase in the routine use of EMG for PLFs followed by a steady decline. Regional differences were observed in the utility of EMG for PLFs. The risk of neurological complications following PLF in the absence of spinal deformity is low and the routine use of EMG for PLF may not decrease the risk., Level of Evidence: 4.

Study Design: A retrospective database study., Objective: The goal of this study was to (1) evaluate the trends in the use of intraoperative neuromonitoring (ION) for anterior cervical discectomy and fusion (ACDF) surgery in the United States and (2) assess the incidence of neurological injuries after ACDFs with and without ION., Summary of Background Data: Somatosensory-evoked potentials (SSEPs) and motor-evoked potentials (MEPs) are the commonly used ION modalities for ACDFs. Controversy exists on the routine use of ION for ACDFs and there is limited literature on national practice patterns of its use., Methods: A retrospective review was performed using the PearlDiver Patient Record Database to identify cases of spondylotic myelopathy and radiculopathy that underwent ACDF from 2007 to 2014. The type of ION modality used and the rates of neurological injury after surgery were assessed., Results: During the study period, 15,395 patients underwent an ACDF. Overall, ION was used in 2627 (17.1%) of these cases. There was a decrease in the use of ION for ACDFs from 22.8% in 2007 to 4.3% use in 2014 (P < 0.0001). The ION modalities used for these ACDFs were quite variable: SSEPs only (48.7%), MMEPs only (5.3%), and combined SSEPs and MMEPs (46.1%). Neurological injuries occurred in 0.23% and 0.27% of patients with and without ION, respectively (P = 0.84). Younger age was associated with a higher utility of ION (<45: 20.3%, 45-54: 19.3%, 55-64: 16.6%, 65-74: 14.3%, and >75: 13.6%, P < 0.0001). Significant regional variability was observed in the utility of ION for ACDFs across the country (West; 21.9%, Midwest; 12.9% (P < 0.0001)., Conclusion: There has been a significant decrease in the use of ION for ACDFs. Furthermore, there was significant age and regional variability in the use of ION for ACDFs. Use of ION does not further prevent the rate of postoperative neurological complications for ACDFs as compared with the cases without ION. The utility of routine ION for ACDFs is questionable., Level of Evidence: 3.

Background Context: Minimally invasive sacroiliac (SI) joint fusion has become increasingly relevant in recent years as a treatment for SI joint pathology. Previous studies have found minimally invasive SI fusion to be an effective and safe treatment option for chronic SI joint pain. However, these studies have been primarily single-center, case-based, or manufacturer-sponsored investigations, and as such their findings are limited to their sample populations., Purpose: The aim of this study was to investigate the safety of minimally invasive SI fusion using a large nationwide sample group to more accurately identify complication rates of this increasingly popular procedure., Study Design/setting: This is a retrospective database study., Patient Sample: The sample includes patients within the orthopedic subset of Humana database who underwent minimally invasive SI fusion between 2007 and 2014., Outcome Measures: Complications and novel lumbar and nerve pathology were the outcome measures., Methods: Patients undergoing minimally invasive SI fusion from 2007 to 2014 were identified using the Pearl Diver patient record database (Pearl Diver Technologies, West Conshohocken, PA, USA) from the nationwide private insurance provider Humana Inc. This approach provided access to records of over 18 million patients in every major geographic region of the country. Using the ICD-9 diagnosis codes (International Classification of Diseases 9th edition), data from patient records were analyzed to reveal incidence of postoperative infection, pain, osteomyelitis, joint derangement, urinary tract infection, and novel lumbar and nervous system pathology., Results: Four hundred sixty-nine patients (305 female; 164 male) within the Humana insurance database received minimally invasive SI fusion between 2007 and 2014. Data from these patients showed a substantial increase in the use of the procedure over this 7-year period. Among these patients, an overall complication rate of 13.2% (n=62) was seen at 90 days postoperatively and 16.4% (n=77) at 6 months. The number of patients receiving a first time diagnosis of lumbar pathology following minimally invasive SI fusion in the sample population was also analyzed. The incidence of novel lumbar pathology in this population was 3.6% (n=17) at 90 days postoperatively and 5.3% (n=25) at 6 months. Men experienced diagnoses of novel lumbar pathology at higher rates than women within both 90 days (men=6.7%; women≤3.3%) and 6 months (men=9.1%; women≤3.3%) of the procedure (p<.01)., Conclusions: The results of this study show that minimally invasive SI joint fusion could possibly carry higher risks of complications than previously stated. These findings are useful for physicians and patients when considering treatment for chronic SI joint pain., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The purpose of this review was to compare the efficacy and safety of synthetic bone graft substitutes versus autograft or allograft for the treatment of lumbar and cervical spinal degenerative diseases. Multiple major medical reference databases were searched for studies that evaluated spinal fusion using synthetic bone graft substitutes (either alone or with an autograft or allograft) compared with autograft and allograft. Randomized controlled trials (RCT) and cohort studies with more than 10 patients were included. Radiographic fusion, patient-reported outcomes, and functional outcomes were the primary outcomes of interest. The search yielded 214 citations with 27 studies that met the inclusion criteria. For the patients with lumbar spinal degenerative disease, data from 19 comparative studies were included: 3 RCTs, 12 prospective, and 4 retrospective studies. Hydroxyapatite (HA), HA+collagen, β-tricalcium phosphate (β-TCP), calcium sulfate, or polymethylmethacrylate (PMMA) were used. Overall, there were no differences between the treatment groups in terms of fusion, functional outcomes, or complications, except in 1 study that found higher rates of HA graft absorption. For the patients with cervical degenerative conditions, data from 8 comparative studies were included: 4 RCTs and 4 cohort studies (1 prospective and 3 retrospective studies). Synthetic grafts included HA, β-TCP/HA, PMMA, and biocompatible osteoconductive polymer (BOP). The PMMA and BOP grafts led to lower fusion rates, and PMMA, HA, and BOP had greater risks of graft fragmentation, settling, and instrumentation problems compared with iliac crest bone graft. The overall quality of evidence evaluating the potential use and superiority of the synthetic biological materials for lumbar and cervical fusion in this systematic review was low or insufficient, largely due to the high potential for bias and small sample sizes. Thus, definitive conclusions or recommendations regarding the use of these synthetic materials should be made cautiously and within the context of the limitations of the evidence.

OBJECTIVE The efficacy of some demineralized bone matrix (DBM) substances has been demonstrated in the spinal fusion of rats; however, no previous comparative study has reported the efficacy of DBM with human mesenchymal stem cells (hMSCs). There is an added cost to the products with stem cells, which should be justified by improved osteogenic potential. The purpose of this study is to prospectively compare the fusion rates of 3 different commercially available DBM substances, both with and without hMSCs. METHODS Posterolateral fusion was performed in 32 mature athymic nude rats. Three groups of 8 rats were implanted with 1 of 3 DBMs: Trinity Evolution (DBM with stem cells), Grafton (DBM without stem cells), or DBX (DBM without stem cells). A fourth group with no implanted material was used as a control group. Radiographs were obtained at 2, 4, and 8 weeks. The rats were euthanized at 8 weeks. Overall fusion was determined by manual palpation and micro-CT. RESULTS The fusion rates at 8 weeks on the radiographs for Trinity Evolution, Grafton, and DBX were 8 of 8 rats, 3 of 8 rats, and 5 of 8 rats, respectively. A significant difference was found between Trinity Evolution and Grafton (p = 0.01). The overall fusion rates as determined by micro-CT and manual palpation for Trinity Evolution, Grafton, and DBX were 4 of 8 rats, 3 of 8 rats, and 3 of 8 rats, respectively. The Trinity Evolution substance had the highest overall fusion rate, however no significant difference was found between groups. CONCLUSIONS The efficacies of these DBM substances are demonstrated; however, the advantage of DBM with hMSCs could not be found in terms of posterolateral fusion. When evaluating spinal fusion using DBM substances, CT analysis is necessary in order to not overestimate fusion.

Purpose: A retrospective database review was carried out to evaluate the trends and demographics of rhBMP utilization in single-level posterior lumbar fusion (PLF) in the United States., Methods: Patients who underwent single-level PLF from 2005 to 2011 were identified by searching ICD-9 diagnosis and procedure codes in the PearlDiver Patient Records Database (PearlDiver Technologies, Fort Wayne, IN, USA), a national database of orthopaedic insurance records. The year of procedure, age, gender, and region of the United States were recorded for each patient. Results were reported for each variable as the incidence of procedures identified per 100,000 patients searched in the database., Results: Totally 5158 patients had single-level PLF in this study. The average rate of single-level PLF with rhBMP utilization maintained at a relatively stable level (19.1-23.5%) from 2005 to 2009, but sharply decreased to 6.8% in 2010 and 6.9% in 2011. The overall incidence of single-level PLF without rhBMP (1.37 cases per 100,000 patients) was more than five times of the incidence of single-level PLF with rhBMP (0.27 cases per 100,000 patients) (P < 0.01). The average rate of single-level PLF with rhBMP utilization is highest in Midwest (18.7%), followed by West (18.4%), South (16.4%) and Northeast (11.5%). The highest incidence of single-level PLF with rhBMP was observed in the group aged 70-74 years with an incidence of 0.33 per 100,000 patients., Conclusions: The incidence of rhBMP utilization in single-level PLF increased from 2006 to 2009, but dropped to a low level in 2010 and 2011. The Northeast region had the lowest incidence of rhBMP utilization. The group aged 70-74 years trended to have the higher incidence of single-level PLF with rhBMP utilization.

Object: The objective of this study was to compare the incidence of degeneration and need for subsequent fusion surgery between patients who were treated nonsurgically and patients treated with fusion after a diagnosis of thoracic-or lumbar-level fracture without degenerative disease., Methods: The authors performed a retrospective study of Orthopedic United Healthcare patients diagnosed with thoracic or lumbar fracture. Patients were filtered into thoracic and lumbar fracture groups using diagnostic codes and then assigned to one of 2 treatment subgroups (fusion surgery or no surgery) on the basis of procedural codes. Disc degeneration and follow-up surgery were recorded. Chi-square statistical analysis was used., Results: Of 3699 patients diagnosed with a thoracic fracture, 117 (3.2%) underwent thoracic fusion and 3215 (86.9%) were treated nonsurgically. Within 3 years, 147 (4.6%) patients from the nonsurgical subgroup and fewer than 11 (0.9%-8.5%) from the fusion subgroup were diagnosed with thoracic disc degeneration. From the nonsurgical subgroup, 11 (0.3%) patients underwent a thoracic surgery related to disc degeneration compared with zero from the fusion group (p > 0.05). Of 5016 patients diagnosed with lumbar fracture, 150 (3.0%) underwent fusion and 4371 (87.1%) had no surgery. Within 3 years, 503 patients (11.5%) from the nonsurgical subgroup and 35 (23.3%) from the fusion subgroup were diagnosed with lumbar disc degeneration (p < 0.05). From the nonsurgical subgroup, 42 (1.0%) went on to have surgery related to disc degeneration, compared with fewer than 11 (0.7%-6.7%) from the fusion subgroup (values not precise due to privacy limitations)., Conclusions: Fusion surgery for thoracic fracture does not appear to increase the likelihood of undergoing future surgery. In the lumbar region, initial fusion surgery appears to increase the incidence of disc degeneration and could potentially necessitate future surgeries.

Purpose: Cell-based therapies such as concentrated bone marrow aspirate (BMA) with allograft and demineralized bone matrix (DBM) have been developed as a potential alternative to iliac crest bone graft (ICBG) in spinal fusion. BMA contains mesenchymal stem cells (MSCs) and growth factors that confer osteogenic and osteoinductive potential to osteoconductive scaffolds like allograft and DBM. It is well established that there is an age-related decline in bone marrow MSC population and efficacy. This might be problematic in spine arthrodesis when utilizing BMA derived from elderly patients as a fusion aide. The goal of this study was to describe the outcomes of concentrated BMA with allograft and DBM in elderly patients undergoing posterolateral and interbody lumbar fusion., Methods: Thirty-one patients, age 65 and older, with a minimum of 12 months follow-up underwent combined primary posterolateral and transforaminal lumbar interbody fusion. Radiographic fusion, complications, reoperation rates and clinical outcomes were assessed. Multiple logistic regression analysis was used to examine the effects of variables such as patient age, gender, smoking, osteoporosis, Charlson co-morbidity index score, single versus multilevel fusion, length of hospital stay, and length of follow-up time on fusion outcome., Results: The overall rate of a solid fusion (i.e. the concomitant presence of solid posterolateral and interbody fusion in a patient) was 83.9 % (26/31). Specifically, radiographic evidence of a successful posterolateral fusion was 83.9 % (26/31) while the radiographic evidence of a successful interbody fusion was 96.8 % (30/31). Using logistic regression analysis, none of the variables of interest had an association with non-solid unions. One (3.2 %) patient developed a seroma and one (3.2 %) patient developed clinical pseudarthrosis. None of the patients developed hardware-related complications or graft donor site morbidities. Five (16.1 %) patients required reoperation. Excellent or good results were achieved in 83.9 % of patients., Conclusions: Despite the concerns of reduced fusion potential in elderly patients, autologous concentrated BMA mixed with allograft and DBM in posterolateral and interbody fusions can achieve successful fusion rates with good clinical outcomes and low complication rates.

Background Context: There is a lack of agreement among spine surgeons as to the best surgical treatment modality for many degenerative lumbar diseases. Although there are many studies examining trends in spinal surgery, specific studies reporting the variations in surgical treatment in the United States for these diseases are lacking., Purpose: The aim of this study was to analyze trends in lumbar spinal fusion methods for common lumbar pathologies in the United States., Study Design/setting: National insurance database review: 2004-2009., Patient Sample: Data is taken from United Healthcare and represents more than 25 million patients., Outcome Measures: No outcomes were measured in this study., Methods: Using a private insurance database, we identified patients who underwent one of five types of instrumented single-level lumbar spinal fusion for the 10 most common primary diagnoses. Surgery rates were reviewed from 2004 to 2009 and were stratified according to patient age, patient gender, and region in the United States. Poisson regression analysis was performed to determine regional and demographic differences in treatment modality. The authors received no funds in support of this work., Results: A total of 23,986 patients met our search criteria. Of the five fusion types, posterior lumbar interbody fusion (PLIF) with posterolateral fusion (PLF) was the most common (45%), followed by PLF (19%), anterior lumbar interbody fusion (ALIF, 16%), PLIF (10%), and ALIF with PLF (9%). There was a significant increase in PLIF with PLF (p<.0001), PLIF (p<.0001), PLF (p=.012), ALIF (p<.0001), and ALIF with PLF (p<.0001) from 2004 to 2009. After controlling for gender, there were significant differences between regions for all fusion types (p<.0001). The likelihood of a posterior fusion increased with age. Anterior fusions were more common in the 30- to 49-year-old age range than in patents older than 50. For patients in age groups older than 30, there was an increased number who underwent a circumferential fusion or an ALIF (p<.022). Fusion types were significantly different between genders (p<.026). Both genders had an overall increase in the number of fusions (p<.001) over the time period studied., Conclusions: There are large differences in the United States for surgical treatment methods for lumbar spine pathology. These differences are likely multifactorial, with both patient and surgeon traits playing a role. Illustrating these differences will hopefully lead to outcomes research to determine the indications, efficacy, and appropriateness of these surgical methods, an important step on the path toward standardization of care., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background Context: The nonunion rate after lumbar spinal fusion is as high as 25%. Recombinant human bone morphogenetic protein 2 (rhBMP2) has been used as a biological adjunct to promote bony fusion. However, recently there have been concerns about BMP2. Oxysterol 133 (Oxy133) has been shown to promote excellent fusion rates in rodent lumbar spine models and offers a potential alternative to rhBMP2., Purpose: The purpose of this study was to compare the fusion rate of rhBMP2 and Oxy133 in a randomized controlled trial using a posterolateral lumbar rabbit spinal fusion model., Study Design: This was a randomized control animal study., Methods: Twenty-four male adult white New Zealand rabbits (3-3.5 kg) underwent bilateral posterolateral lumbar spinal fusion at L4-L5. Rabbits were divided into four groups: control (A), 30-μg rhBMP2 (B), 20-mg Oxy133 (C), and 60-mg Oxy133 (D). At 4 weeks, fusion was evaluated by fluoroscopy, and at 8 weeks, the rabbits were sacrificed and fusion was evaluated radiographically, by manual palpation, and with microcomputed tomography., Results: Fusion rates by radiographic analysis at 8 weeks were Group A, 40.0%; Group B, 91.7%; Group C, 91.7%; and Group D, 100%. Evaluation of fusion masses by manual palpation of excised spines after sacrifice showed the following fusion rates: Group A, 0%; Group B, 83.3%; Group C, 83.3%; and Group D, 90%. Microcomputed tomography scanning confirmed these findings., Conclusions: These findings in a rabbit model demonstrate that both 20- and 60-mg Oxy133 doses promote fusion that is equivalent to fusion induced by 30-μg rhBMP2 and significantly greater than the control group. The present findings confirm that Oxy133 is a promising candidate for therapeutic development as an alternative to rhBMP2 to promote spinal fusion., (Copyright © 2015 Elsevier Inc. All rights reserved.)

In an effort to diminish pain or progressive instability, due to either the pathological process or as a result of surgical decompression, one of the primary goals of a fusion procedure is to achieve a solid arthrodesis. Assuming that pain and disability result from lost mechanical integrity of the spine, the objective of a fusion across an unstable segment is to eliminate pathological motion and improve clinical outcome. However, conclusive evidence of this correlation, between successful fusion and clinical outcome, remains elusive, and thus the necessity of documenting successful arthrodesis through radiographic analysis remains debatable. Although a definitive cause and effect relationship has not been demonstrated, there is moderate evidence that demonstrates a positive association between radiographic presence of fusion and improved clinical outcome. Due to this growing body of literature, it is recommended that strategies intended to enhance the potential for radiographic fusion are considered when performing a lumbar arthrodesis for degenerative spine disease.

Interbody fusion techniques have been promoted as an adjunct to lumbar fusion procedures in an effort to enhance fusion rates and potentially improve clinical outcome. The medical evidence continues to suggest that interbody techniques are associated with higher fusion rates compared with posterolateral lumbar fusion (PLF) in patients with degenerative spondylolisthesis who demonstrate preoperative instability. There is no conclusive evidence demonstrating improved clinical or radiographic outcomes based on the different interbody fusion techniques. The addition of a PLF when posterior or anterior interbody lumbar fusion is performed remains an option, although due to increased cost and complications, it is not recommended. No substantial clinical benefit has been demonstrated when a PLF is included with an interbody fusion. For lumbar degenerative disc disease without instability, there is moderate evidence that the standalone anterior lumbar interbody fusion (ALIF) has better clinical outcomes than the ALIF plus instrumented, open PLF. With regard to type of interbody spacer used, frozen allograft is associated with lower pseudarthrosis rates compared with freeze-dried allograft; however, this was not associated with a difference in clinical outcome.

A comprehensive economic analysis generally involves the calculation of indirect and direct health costs from a societal perspective as opposed to simply reporting costs from a hospital or payer perspective. Hospital charges for a surgical procedure must be converted to cost data when performing a cost-effectiveness analysis. Once cost data has been calculated, quality-adjusted life year data from a surgical treatment are calculated by using a preference-based health-related quality-of-life instrument such as the EQ-5D. A recent cost-utility analysis from a single study has demonstrated the long-term (over an 8-year time period) benefits of circumferential fusions over stand-alone posterolateral fusions. In addition, economic analysis from a single study has found that lumbar fusion for selected patients with low-back pain can be recommended from an economic perspective. Recent economic analysis, from a single study, finds that femoral ring allograft might be more cost-effective compared with a specific titanium cage when performing an anterior lumbar interbody fusion plus posterolateral fusion.

Establishing an appropriate treatment strategy for patients presenting with low-back pain, in the absence of stenosis or spondylolisthesis, remains a controversial subject. Inherent to this situation is often an inability to adequately identify the source of low-back pain to justify various treatment recommendations, such as lumbar fusion. The current evidence does not identify a single best treatment alternative for these patients. Based on a number of prospective, randomized trials, comparable outcomes, for patients presenting with 1- or 2-level degenerative disc disease, have been demonstrated following either lumbar fusion or a comprehensive rehabilitation program with a cognitive element. Limited access to such comprehensive rehabilitative programs may prove problematic when pursuing this alternative. For patients whose pain is refractory to conservative care, lumbar fusion is recommended. Limitations of these studies preclude the ability to present the most robust recommendation in support of lumbar fusion. A number of lesser-quality studies, primarily case series, also support the use of lumbar fusion in this patient population.