The effect of anterior lumbar interbody fusion staging order on perioperative complications in circumferential lumbar fusions performed within the same hospital admission.

OBJECTIVE: Anterior lumbar interbody fusion (ALIF) is a powerful technique that provides wide access to the disc space and allows for large lordotic grafts. When used with posterior spinal fusion (PSF), the procedures are often staged within the same hospital admission. There are limited data on the perioperative risk profile of ALIF-first versus PSF-first circumferential fusions performed within the same hospital admission. In an effort to understand whether these procedures are associated with different perioperative complication profiles, the authors performed a retrospective review of their institutional experience in adult patients who had undergone circumferential lumbar fusions. METHODS: The electronic medicals records of patients who had undergone ALIF and PSF on separate days within the same hospital admission at a single academic center were retrospectively analyzed. Patients carrying a diagnosis of tumor, infection, or traumatic fracture were excluded. Demographics, surgical characteristics, and perioperative complications were collected and assessed. RESULTS: A total of 373 patients, 217 of them women (58.2%), met the inclusion criteria. The mean age of the study cohort was 60 years. Surgical indications were as follows: degenerative disease or spondylolisthesis, 171 (45.8%); adult deformity, 168 (45.0%); and pseudarthrosis, 34 (9.1%). The majority of patients underwent ALIF first (321 [86.1%]) with a mean time of 2.5 days between stages. The mean number of levels fused was 2.1 for ALIF and 6.8 for PSF. In a comparison of ALIF-first to PSF-first cases, there were no major differences in demographics or surgical characteristics. Rates of intraoperative complications including venous injury were not significantly different between the two groups. The rates of postoperative ileus (11.8% vs 5.8%, p = 0.194) and ALIF-related wound complications (9.0% vs 3.8%, p = 0.283) were slightly higher in the ALIF-first group, although the differences did not reach statistical significance. Rates of other perioperative complications were no different. CONCLUSIONS: In patients undergoing staged circumferential fusion with ALIF and PSF, there was no statistically significant difference in the rate of perioperative complications when comparing ALIF-first to PSF-first surgeries.

Management of aortic injury during minimally invasive lateral lumbar interbody fusion.

PURPOSE: Minimally invasive lateral approaches to the lumbar spine allow for interbody fusion with good visualization of the disk space, minimal blood loss, and decreased length of stay. Major neurologic, vascular, and visceral complications are rare with this approach; however, the steps in management for severe vascular injuries are not well defined. We present a case report of aortic injury during lateral interbody fusion and discuss the use of endovascular repair. METHODS: This study is a case report of an intraoperative aortic injury. RESULTS: A 59-year-old male with ankylosing spondylitis suffered an acute L1 Chance fracture after mechanical fall. He was taken to the operating room for a T10-L4 posterior instrumented fusion followed by a minimally invasive L1-L2 lateral interbody fusion for anterior column support. During the discectomy, brisk arterial bleeding was encountered due to an aortic injury. The vascular surgery team expanded the incision in an attempt to control the bleeding but with limited success. The patient underwent intraoperative angiogram with placement of stent grafts at the level of the injury followed by completion of the interbody fusion. Despite the potentially catastrophic nature of this injury, the patient made a good recovery and was discharged home in stable condition with no new neurologic deficits. CONCLUSIONS: This case highlights the importance of immediate recognition and imaging of any potential vascular injury during minimally invasive lateral interbody fusion. Given the poor outcomes associated with attempted open repair, endovascular techniques provide a valuable tool for the treatment of these complex injuries with significantly less morbidity.

The unreimbursed costs of preventing revision surgery in adult spinal deformity: analysis of cost-effectiveness of proximal junctional failure prevention with ligament augmentation.

OBJECTIVE Proximal junctional kyphosis (PJK) is a well-recognized complication of surgery for adult spinal deformity and is characterized by increased kyphosis at the upper instrumented vertebra (UIV). PJK prevention strategies have the potential to decrease morbidity and cost by reducing rates of proximal junctional failure (PJF), which the authors define as radiographic PJK plus clinical sequelae requiring revision surgery. METHODS The authors performed an analysis of 195 consecutive patients with adult spinal deformity. Age, sex, levels fused, upper instrumented vertebra (UIV), use of 3-column osteotomy, pelvic fixation, and mean time to follow-up were collected. The authors also reviewed operative reports to assess for the use of surgical adjuncts targeted toward PJK prevention, including ligament augmentation, hook fixation, and vertebroplasty. The cost of surgery, including direct and total costs, was also assessed at index surgery and revision surgery. Only revision surgery for PJF was included. RESULTS The mean age of the cohort was 64 years (range 25-84 years); 135 (69%) patients were female. The mean number of levels fused was 10 (range 2-18) with the UIV as follows: 2 cervical (1%), 73 upper thoracic (37%), 108 lower thoracic (55%), and 12 lumbar (6%). Ligament augmentation was used in 99 cases (51%), hook fixation in 60 cases (31%), and vertebroplasty in 71 cases (36%). PJF occurred in 18 cases (9%). Univariate analysis found that ligament augmentation and hook fixation were associated with decreased rates of PJF. However, in a multivariate model that also incorporated age, sex, and UIV, only ligament augmentation maintained a significant association with PJF reduction (OR 0.196, 95% CI 0.050-0.774; p = 0.020). Patients with ligament augmentation, compared with those without, had a higher cost of index surgery, but ligament augmentation was overall cost effective and produced significant cost savings. In sensitivity analyses in which we independently varied the reduction in PJF, cost of ligament augmentation, and cost of reoperation by ± 50%, ligament augmentation remained a cost-effective strategy for PJF prevention. CONCLUSIONS Prevention strategies for PJK/PJF are limited, and their cost-effectiveness has yet to be established. The authors present the results of 195 patients with adult spinal deformity and show that ligament augmentation is associated with significant reductions in PJF in both univariate and multivariate analyses, and that this intervention is cost-effective. Future studies will need to determine if these clinical results are reproducible, but for high-risk cases, these data suggest an important role of ligament augmentation for PJF prevention and cost savings.

Cost-effectiveness development for the postoperative care of craniotomy patients: a safe transitions pathway in neurological surgery.

OBJECTIVE The authors' institution is in the top 5th percentile for hospital cost in the nation, and the neurointensive care unit (NICU) is one of the costliest units. The NICU is more expensive than other units because of lower staff/patient ratio and because of the equipment necessary to monitor patient care. The cost differential between the NICU and Neuro transitional care unit (NTCU) is $1504 per day. The goal of this study was to evaluate and to pilot a program to improve efficiency and lower cost by modifying the postoperative care of patients who have undergone a craniotomy, sending them to the NTCU as opposed to the NICU. Implementation of the pilot will expand and utilize neurosurgery beds available on the NTCU and reduce the burden on NICU beds for critically ill patient admissions. METHODS Ten patients who underwent craniotomy to treat supratentorial brain tumors were included. Prior to implementation of the pilot, inclusion criteria were designed for patient selection. Patients included were less than 65 years of age, had no comorbid conditions requiring postoperative intensive care unit (ICU) care, had a supratentorial meningioma less than 3 cm in size, had no intraoperative events, had routine extubation, and underwent surgery lasting fewer than 5 hours and had blood loss less than 500 ml. The Safe Transitions Pathway (STP) was started in August 2016. RESULTS Ten tumor patients have utilized the STP (5 convexity meningiomas, 2 metastatic tumors, 3 gliomas). Patients' ages ranged from 29 to 75 years (median 49 years; an exception to the age limit of 65 years was made for one 75-year-old patient). Discharge from the hospital averaged 2.2 days postoperative, with 1 discharged on postoperative day (POD) 1, 7 discharged on POD 2, 1 discharged on POD 3, and 1 discharged on POD 4. Preliminary data indicate that quality and safety for patients following the STP (moving from the operating room [OR] to the neuro transitional care unit [OR-NTCU]) are no different from those of patients following the traditional OR-NICU pathway. No patients required escalation in level of nursing care, and there were no readmissions. This group has been followed for greater than 1 month, and there were no morbidities. CONCLUSIONS The STP is a new and efficient pathway for the postoperative care of neurosurgery patients. The STP has reduced hospital cost by $22,560 for the first 10 patients, and there were no morbidities. Since this pilot, the authors have expanded the pathway to include other surgical cases and now routinely schedule craniotomy patients for the (OR-NTCU) pathway. The potential cost reduction in one year could reach $500,000 if we reach our potential of 20 patients per month.

Tubular microdiscectomy: techniques, complication avoidance, and review of the literature.

OBJECTIVE Microendoscopic discectomy is a minimally invasive surgery technique that was initially described in 1997. It allows surgeons to work with 2 hands through a small-diameter, operating table-mounted tubular retractor, and to apply standard microsurgical techniques in which a small skin incision and minimal muscle dissection are used. Whether the surgeon chooses to use an endoscope or a microscope for visualization, the technique uses the same type of retractor and is thus called tubular microdiscectomy. The goal in this study was to review the current literature, examine the level of evidence supporting tubular microdiscectomy, and describe surgical techniques for complication avoidance. METHODS The authors performed a systematic PubMed review using the terms "microdiscectomy trial," "tubular and open microdiscectomy," "microendoscopic open discectomy," and "minimally invasive open microdiscectomy OR microdiskectomy." Of 317 references, 10 manuscripts were included for analysis based on study design, relevance, and appropriate comparison of open to tubular discectomy. RESULTS Similar and very favorable clinical outcomes can be expected from tubular and standard microdiscectomy. Studies have demonstrated equivalent operating times for both procedures, with lower blood loss and shorter hospital stays associated with tubular microdiscectomy. Furthermore, postoperative analgesic usage has been shown to be significantly lower after tubular microdiscectomy. Overall rates of complications are no different for tubular and standard microdiscectomy. CONCLUSIONS Prospective randomized trials have been used to evaluate outcomes of common minimally invasive lumbar spine procedures. For lumbar discectomy, Level I evidence supports equivalently good outcomes for tubular microdiscectomy compared with standard microdiscectomy. Likewise, Level I data indicate similar safety profiles and may indicate lower blood loss for tubular microdiscectomy. Future studies should examine the comparative value of these procedures.

Sacral epidural arteriovenous fistulas: imitators of spinal dural arteriovenous fistulas with different pathologic anatomy: report of three cases and review of the literature.

BACKGROUND: Sacral epidural arteriovenous fistulas (eAVFs) are rare and often misdiagnosed because of the incongruence between the thoracic level of clinical deficits and the sacral location of the offending pathology. Failure to diagnose this lesion delays treatment, resulting in prolonged venous hypertension in the cord, progressive neurological deterioration, and decreased chances of recovery. METHODS: A single-institution case series and the published literature were reviewed. RESULTS: Three patients had sacral eAVFs are located in the ventral epidural space with outflow connections to radicular veins that arterialized spinal cord veins, all presenting with thoracic myelopathy, venous engorgement, and delayed diagnosis. All eAVFs were occluded completely with radiographic and clinical improvement. CONCLUSIONS: Sacral eAVF pathophysiology, namely venous hypertension and compromised spinal cord circulation, is exactly the same as dural AVFs, as is their treatment: the interruption of outflow by occlusion of the draining vein, which effectively eliminates venous hypertension, without occlusion of the actual fistula itself. Epidural exposure of sacral eAVFs is not necessary, whereas complete intradural occlusion of their radicular drainage is. Draining radicular veins intermingle with the nerve roots and their occasional multiplicity makes them more difficult to identify intraoperatively.

The transsylvian approach for resection of insular gliomas: technical nuances of splitting the Sylvian fissure.

Insular gliomas represent a unique surgical challenge due to the complex anatomy and nearby vascular elements associated within the Sylvian fissure. For certain tumors, the transsylvian approach provides an effective technique for achieving maximal safe resection. The goal of this manuscript and video are to present and discuss the surgical nuances and appropriate application of splitting the Sylvian fissure. Our hope is that this video highlights the safety and efficacy of the transsylvian approach for appropriately selected insular gliomas.

Completely Minimally Invasive Implant Removal and Transforaminal Lumbar Interbody Fusion for Adjacent Segment Disease: Case Series and Operative Video.

BACKGROUND AND OBJECTIVES: Adjacent segment disease is a relatively common late complication after lumbar fusion. If symptomatic, certain patients require fusion of the degenerated adjacent segment. Currently, there are no posterior completely minimally invasive techniques described for fusion of the adjacent segment above or below a previous fusion. We describe here a novel minimally invasive technique for both implant removal (MIS-IR) and adjacent level transforaminal lumbar interbody fusion (MIS-TLIF) for lumbar stenosis. METHODS: Demographic, surgical, and radiographic outcome data were collected for patients with lumbar stenosis and previous lumbar fusion, who were treated with MIS-IR and MIS-TLIF through the same incision. Radiographic outcomes were assessed postoperatively and complications were assessed at the primary end point of 3 months. RESULTS: A total of 14 patients (7 female and 7 male), with average age 64.6 years (SD 13.4), were included in this case series. Nine patients had single-level MIS-IR with single-level MIS-TLIF. Three patients had 2-level MIS-IR with single-level MIS-TLIF. Two patients had single-level MIS-IR with 2-level MIS-TLIF. Only 1 patient had a postoperative complication-hematoma requiring same-day evacuation. There were no other complications at the primary end point and no fusion failure at the hardware removal levels to date (average follow-up, 11 months). Average increases in posterior disk height and foraminal height after MIS-TLIF were 4.44, and 2.18 mm, respectively. CONCLUSION: Minimally invasive spinal IR can be successfully completed along with adjacent level TLIF through the same incisions, via an all-posterior approach.

Comparative Review of the Socioeconomic Burden of Lower Back Pain in the United States and Globally.

Internationally, the United States (U.S.) cites the highest cost burden of low back pain (LBP). The cost continues to rise, faster than the rate of inflation and overall growth of health expenditures. We performed a comprehensive literature review of peer-reviewed and non- peer-reviewed literature from PubMed, Scopus, and Google Scholar for contemporary data on prevalence, cost, and projected future costs. Policymakers in the U.S. have long attempted to address the high-cost burden of LBP through limiting low-value services and early imaging. Despite these efforts, costs (~$40 billion; ~$2,000/patient/yr) continue to rise with increasing rates of unindicated imaging, high rates of surgery, and subsequent revision surgery without proper trial of non-pharmacologic measures and no corresponding reduction in LBP prevalence. Globally, the overall prevalence of LBP continues to rise largely secondary to a growing aging population. Cost containment methods should focus on careful and comprehensive clinical assessment of patients to better understand when more resource-intensive interventions are indicated.

The Evolution of Risk Assessment in Spine Surgery: A Narrative Review.

BACKGROUND: Risk assessment is critically important in elective and high-risk interventions, particularly spine surgery. This narrative review describes the evolution of risk assessment from the earliest instruments focused on general surgical risk stratification, to more accurate and spine-specific risk calculators that quantified risk, to the current era of big data. METHODS: The PubMed and SCOPUS databases were queried on October 11, 2023 using search terms to identify risk assessment tools (RATs) in spine surgery. A total of 108 manuscripts were included after screening with full-text review using the following inclusion criteria: 1) study population of adult spine surgical patients, 2) studies describing validation and subsequent performance of preoperative RATs, and 3) studies published in English. RESULTS: Early RATs provided stratified patients into broad categories and allowed for improved communication between physicians. Subsequent risk calculators attempted to quantify risk by estimating general outcomes such as mortality, but then evolved to estimate spine-specific surgical complications. The integration of novel concepts such as invasiveness, frailty, genetic biomarkers, and sarcopenia led to the development of more sophisticated predictive models that estimate the risk of spine-specific complications and long-term outcomes. CONCLUSIONS: RATs have undergone a transformative shift from generalized risk stratification to quantitative predictive models. The next generation of tools will likely involve integration of radiographic and genetic biomarkers, machine learning, and artificial intelligence to improve the accuracy of these models and better inform patients, surgeons, and payers.

Epigenetic age biomarkers and risk assessment in adult spinal deformity: a novel association of biological age with frailty and disability.

OBJECTIVE: Surgery for spinal deformity has the potential to improve pain, disability, function, self-image, and mental health. These surgical procedures carry significant risk and require careful selection, optimization, and risk assessment. Epigenetic clocks are age estimation tools derived by measuring the methylation patterns of specific DNA regions. The study of biological age in the adult deformity population has the potential to shed insight onto the molecular basis of frailty and to improve current risk assessment tools. METHODS: Adult patients who underwent deformity surgery were prospectively enrolled. Preoperative whole blood samples were used to assess epigenetic age and telomere length. DNA methylation patterns were quantified and processed to extract 4 principal component (PC)-based epigenetic age clocks (PC Horvath, PC Hannum, PC PhenoAge, and PC GrimAge) and the instantaneous pace of aging (DunedinPACE). Telomere length was assessed using both quantitative polymerase chain reaction (telomere to single gene [T/S] ratio) and a methylation-based telomere estimator (PC DNAmTL). Patient demographic and surgical data included age, BMI, American Society of Anesthesiologists Physical Status Classification System class, and scores on the Charlson Comorbidity Index, adult spinal deformity frailty index (ASD-FI), Edmonton Frail Scale (EFS), Oswestry Disability Index, and Scoliosis Research Society-22r questionnaire (SRS-22r). Medical or surgical complications within 90 days of surgery were collected. Spearman correlations and beta coefficients (ß) from linear regression, adjusted for BMI and sex, were calculated. RESULTS: Eighty-three patients were enrolled with a mean age of 65 years, and 45 were women (54%). All patients underwent posterior fusion with a mean of 11 levels fused and 33 (40%) 3-column osteotomies were performed. Among the epigenetic clocks adjusted for BMI and sex, DunedinPACE showed a significant association with ASD-FI (ß = 0.041, p = 0.002), EFS (ß = 0.696, p = 0.026), and SRS-22r (ß = 0.174, p = 0.013) scores. PC PhenoAge showed associations with ASD-FI (ß = 0.029, p = 0.028) and SRS-22r (ß = 0.159, p = 0.018) scores. PC GrimAge showed associations with ASD-FI (ß = 0.029, p = 0.037) and SRS-22r (ß = 0.161, p = 0.025) scores. Patients with postoperative complications were noted to have shorter telomere length (T/S 0.790 vs 0.858, p = 0.049), even when the analysis controlled for BMI and sex (OR = 1.71, 95% CI 1.07-2.87, p = 0.031). CONCLUSIONS: Epigenetic clocks showed significant associations with markers of frailty and disability, while patients with postoperative complications had shorter telomere length. These data suggest a potential role for aging biomarkers as components of surgical risk assessment. Integrating biological age into current risk calculators may improve their accuracy and provide valuable information for patients, surgeons, and payers.

The Effect of Osteoporosis on Complications and Reoperation Rates After Surgical Management of Adult Thoracolumbar Spinal Deformity: A Systematic Review and Meta Analysis.

STUDY DESIGN: Systematic Review. OBJECTIVES: While substantial research has explored the impact of osteoporosis on patients undergoing adult spinal deformity (ASD) correction, the literature remains inconclusive. As such, the purpose of this study is to synthesize and analyze existing studies pertaining to osteoporosis as a predictor of postoperative outcomes in ASD surgery. METHODS: We performed a systematic review and meta-analysis to determine the effect that a diagnosis of osteoporosis, based on ICD-10 coding, dual-energy X-ray absorptiometry (DEXA) or computed tomography, has on the incidence of adverse outcomes following surgical correction of ASD. Statistical analysis was performed using Comprehensive Meta-Analysis (Version 2) using a random effects model to account for heterogeneity between studies. RESULTS: After application of inclusion and exclusion criteria, 36 and 28 articles were included in the systematic review and meta-analysis, respectively. The meta-analysis identified greater rates of screw loosening amongst osteoporotic patients (70.5% vs 31.9%, P = .009), and decreased bone mineral density in patients who developed proximal junctional kyphosis (PJK) (.69 vs .79 g/cm2, P = .001). The systematic review demonstrated significantly increased risk of any complication, reoperation, and proximal junctional failure (PJF) associated with reduced bone density. No statistical difference was observed between groups regarding fusion rates, readmission rates, and patient-reported and/or functional outcome scores. CONCLUSION: This study demonstrates a higher incidence of screw loosening, PJK, and revision surgery amongst osteoporotic ASD patients. Future investigations should explore outcomes at various follow-up intervals in order to better characterize how risk changes with time and to tailor preoperative planning based on patient-specific characteristics.

Integration of Chronological Age Does Not Improve the Performance of a Mixed-Effect Model Using Comorbidity Burden and Frailty to Predict 90-Day Readmission After Surgery for Degenerative Scoliosis.

OBJECTIVE: We evaluated the contributions of chronological age, comorbidity burden, and/or frailty in predicting 90-day readmission in patients undergoing degenerative scoliosis surgery. METHODS: Patients were identified through the Healthcare Cost and Utilization Project Nationwide Readmissions Database. Frailty was assessed using the Johns Hopkins Adjusted Clinical Groups frailty-defining indicator. Comorbidity was assessed using the Elixhauser Comorbidity Index (ECI). Generalized linear mixed-effects models were created to predict readmission using age, frailty, and/or ECI. Area under the curve (AUC) was compared using DeLong's test. RESULTS: A total of 8104 patients were identified. Readmission rate was 9.8%, with infection representing the most common cause (3.5%). Our first model utilized chronological age, ECI, and/or frailty as primary predictors. The combination of ECI + frailty + age performed best, but the inclusion of chronological age did not significantly improve performance compared to ECI + frailty alone (AUC 0.603 vs. 0.599, P = 0.290). A second model using only chronological age and frailty as primary predictors performed better, however the inclusion of chronological age worsened performance when compared to frailty alone (AUC 0.747 vs. 0.743, P = 0.043). CONCLUSIONS: These data support frailty as a predictor of 90-day readmission within a nationally representative sample. Frailty alone performed better than combinations of ECI and age. Interestingly, the integration of chronological age did not dramatically improve the model's performance. Limitations include the use of a national registry and a single frailty index. This provides impetus to explore biological age, rather than chronological age, as a potential tool for surgical risk assessment.

WITHDRAWN: Biological age and spine surgery-genomics and the future of risk assessment.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://doi.org/10.1016/j.wneu.2023.02.011. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal.

Comparison of Surgical Outcomes Between Anterior and Posterior Cervical Fusions Stratified by Levels Decompressed.

STUDY DESIGN: Retrospective database study. OBJECTIVE: To compare outcomes between 1-, 2-, 3-, and 4- level anterior cervical discectomy and fusions (ACDF) and posterior cervical fusions (PCF) procedures using a national database. SUMMARY OF BACKGROUND DATA: Surgical outcomes involving 3- or 4-level ACDF and PCF cases are not well-described. As there are situations where both ACDF and PCF can be employed, it is important to compare the risks and benefits of both procedures. MATERIALS AND METHODS: Patients who underwent ACDF or PCF between 2010 and 2020 were identified in PearlDiver using current procedural terminology codes. Surgeries done for infectious, traumatic, or neoplastic etiologies were excluded. 2-year reoperations and 90-day readmissions were queried. Surgical complications and transfusions were compiled using ICD-9/10 billing codes. ACDF and PCF procedures were then matched by age, sex, Charlson Comorbidity Index, and a number of levels fused, and the above outcomes were compared. RESULTS: In all, 31,301 PCFs and 110,526 ACDFs were identified. After matching for age, sex, and Charlson Comorbidity Index, a total of 30,353 ACDF and PCF procedures were compared. Three-level and 4-level PCFs had higher rates of 90-day postoperative surgical complications compared with ACDF (OR=2.4 and 2.87, respectively; P <0.001). In addition, higher rates of 90-day readmissions were noted in 3-level PCF compared with 3-level ACDF (OR=1.24, P <0.001). Ninety-day postoperative transfusions were higher in both 3- and 4-level PCFs (OR=2.44 and 18.27, respectively; P <0.001). Two-year reoperations rates were higher for 3-level PCF procedures than 3-level ACDF (OR=1.22; P =0.01). CONCLUSIONS: Patients who underwent 3-4-level ACDF had lower rates of readmission, blood transfusions, and postoperative complications compared with 3-4-level PCF. This data suggests that in cases of 3-4-level pathology with clinical equipoise regarding approach, ACDF may be associated with less short-term morbidity, however, data on fusion rates and adjacent level disease are needed.

Association of telomere length with risk of complications in adult spinal deformity surgery: a pilot study of 43 patients.

OBJECTIVE: Risk stratification is a critical element of surgical planning. Early tools were fairly crude, while newer instruments incorporate disease-specific elements and markers of frailty. It is unknown if discrepancies between chronological and cellular age can guide surgical planning or treatment. Telomeres are DNA-protein complexes that serve an important role in protecting genomic DNA. Their shortening is a consequence of aging and environmental exposures, with well-established associations with diseases of aging and mortality. There are compelling data to suggest that telomere length can provide insight toward overall health. The authors sought to determine potential associations between telomere length and postoperative complications. METHODS: Adults undergoing elective surgery for spinal deformity were prospectively enrolled. Telomere length was measured from preoperative whole blood using quantitative polymerase chain reaction and expressed as the ratio of telomere (T) to single-copy gene (S) abundance (T/S ratio), with higher T/S ratios indicating longer telomere length. Demographic and patient data included age, BMI, and results for the following rating scales: the Adult Spinal Deformity Frailty Index (ASD-FI), Oswestry Disability Index (ODI), Scoliosis Research Society-22r (SRS-22r), American Society of Anesthesiology (ASA) classification, and Charlson Comorbidity Index (CCI). Operative and postoperative complication data (medical or surgical within 90 days) were also collected. RESULTS: Forty-three patients were enrolled, including 31 women (53%), with a mean age of 66 years and a mean BMI of 28.5. The mean number of levels fused was 11, with 21 (48.8%) combined anterior-posterior approaches. Twenty-two patients (51.2%) had a medical or surgical complication. Patients with a postoperative complication had a significantly lower T/S ratio (0.712 vs 0.813, p = 0.008), indicating shorter telomere length, despite a mild difference in age compared with patients without a postoperative complication (68 vs 63 years, p = 0.069). Patients with complications also had higher CCI scores than patients without complications (2.3 vs 3.8, p = 0.004). There were no significant differences in sex, BMI, ASD-FI score, ASA class, preoperative ODI and SRS-22r scores, number of levels fused, or use of three-column osteotomies. In a multivariate model including age, frailty, ASA class, use of an anterior-posterior approach, CCI score, and telomere length, the authors found that short telomere length was significantly associated with postoperative complications. Patients whose telomere length fell in the shortest quartile had the highest risk (OR 18.184, p = 0.030). CONCLUSIONS: Short telomere length was associated with an increased risk of postoperative complications despite only a mild difference in chronological age. Increasing comorbidity scores also trended toward significance. Larger prospective studies are needed; however, these data provide a compelling impetus to investigate the role of biological aging as a component of surgical risk stratification.

Future Data Points to Implement in Adult Spinal Deformity Assessment for Artificial Intelligence Modeling Prediction: The Importance of the Biological Dimension.

Adult spinal deformity (ASD) surgery is still associated with high surgical risks. Machine learning algorithms applied to multicenter databases have been created to predict outcomes and complications, optimize patient selection, and improve overall results. However, the multiple data points currently used to create these models allow for 70% of accuracy in prediction. We need to find new variables that can capture the spectrum of probability that is escaping from our control. These proposed variables are based on patients' biological dimensions, such as frailty, sarcopenia, muscle and bone (tissue) sampling, serological assessment of cellular senescence, and circulating biomarkers that can measure epigenetics, inflammaging, and -omics. Many of these variables are proven to be modifiable and could be improved with proper nutrition, toxin avoidance, endurance exercise, and even surgery. The purpose of this manuscript is to describe the different future data points that can be implemented in ASD assessment to improve modeling prediction, allow monitoring their response to prerehabilitation programs, and improve patient counseling.

Posterior-based resection of spinal meningiomas: an institutional experience of 141 patients with an average of 28 months of follow-up.

OBJECTIVE: Spinal meningiomas pose unique challenges based on the location of their dural attachment. However, there is a paucity of literature investigating the role of dural attachment location on outcomes after posterior-based approach for spinal meningioma resection. The aim of this study was to investigate any differences in outcomes between dural attachment location subgroups in spinal meningioma patients who underwent posterior-based resection. METHODS: This was a single-institution review of patients who underwent resection of a spinal meningioma from 1997 to 2017. Surgical, oncological, and neurological outcomes were compared between patients with varying dural attachments. Multivariate analysis was utilized. RESULTS: A total of 141 patients were identified. The mean age was 62 years, and 110 women were included. The sites of dural attachments were as follows: 16 (11.3%) dorsal, 31 (22.0%) dorsolateral, 17 (12.1%) lateral, 40 (28.4%) ventral, and 37 (26.2%) ventrolateral. Most meningiomas were WHO grade I (92.2%) and in the thoracic spine (61.0%). All patients underwent a posterior approach for tumor resection. There were no differences between subgroups in terms of largest diameter of tumor resected (p = 0.201), gross-total resection (GTR) or subtotal resection (p = 0.362), Simpson grade of resection, perioperative complications (p = 0.116), long-term neurological deficit (p = 0.100), or postoperative radiation therapy (p = 0.971). Cervical spine location was associated with reduced incidence of GTR (OR 0.271, 95% CI 0.108-0.684, p = 0.006) on multivariate analysis. The overall incidence of recurrence/progression was 4.6%, with no difference (p = 0.800) between subgroups. Similarly, the average length of follow-up was 28.1 months, with no difference between subgroups (p = 0.413). CONCLUSIONS: Posterior-based approaches for resection of spinal meningiomas are safe and effective, regardless of dural attachment location, with similar surgical, oncological, and neurological outcomes. Comparison of long-term recurrence rates between dural attachment subgroups is required.

Patient Frailty Influences Outcome After Open, But Not Minimally Invasive, Transforaminal Interbody Fusion: A Case Series of 115 Patients With Lumbar Degenerative Disease.

BACKGROUND: For transforaminal lumbar interbody fusion (TLIF), there are equally good open and minimally invasive surgery (MIS) options. OBJECTIVE: To determine if frailty has a differential effect on outcome for open vs MIS TLIF. METHODS: We performed a retrospective review of 115 TLIF surgeries (1-3 levels) for lumbar degenerative disease performed at a single center; 44 MIS transforaminal interbody fusions and 71 open TLIFs were included. All patients had at least a 2-year follow up, and any revision surgery during that time was recorded. The Adult Spinal Deformity Frailty Index (ASD-FI) was used to separate patients into nonfrail (ASD-FI < 0.3) and frail (ASD-FI > 0.3) cohorts. The primary outcome variables were revision surgery and discharge disposition. Univariate analyses were performed to reveal associations in demographic, radiographic, and surgical data with the outcome variables. Multivariate logistic regression was used to assess independent predictors of outcome. RESULTS: Frailty uniquely predicted both reoperation (odds ratio 8.1, 95% CI 2.5-26.1, P = .0005) and discharge to a location other than home (odds ratio 3.9, 95% CI 1.2-12.7, P = .0239). Post hoc analysis indicated that frail patients undergoing open TLIF had a higher revision surgery rate (51.72%) compared with frail patients undergoing MIS-TLIF (16.7%). Nonfrail patients undergoing open and MIS TLIF had a revision surgery rate of 7.5% and 7.7%, respectively. CONCLUSION: Frailty was associated with increased revision rate and increased probability to discharge to a location other than home after open transforaminal interbody fusions, but not MIS transforaminal interbody fusions. These data suggest that patients with high frailty scores may benefit from MIS-TLIF procedures.

Kickstand Rod With Asymmetric Pedicle Subtraction Osteotomy for Treatment of Adult Kyphoscoliosis With Severe Coronal Imbalance.

BACKGROUND: The kickstand rod has been described for the treatment of severe coronal imbalance. We present a modified description that combines an asymmetric pedicle subtraction osteotomy (PSO) for correction of severe kyphoscoliosis. OBJECTIVE: To describe the use of a temporary kickstand rod. METHODS: Type 1 osteotomies were performed across the main and fractional curves. An asymmetric PSO was performed at the apex of the main curve, and a kickstand rod placed on the concavity anchored from the ilium to a temporary connector above the main curve. Distraction was applied across the kickstand rod because the PSO was closed on the convexity. A permanent rod was placed contralateral to the kickstand, followed by replacement of the kickstand with a permanent rod and bilateral accessory rods. RESULTS: A 66-year-old man presented with kyphoscoliosis causing severe coronal and sagittal imbalance. He underwent L4-S1 anterior lumbar interbody fusion followed by T4-pelvis instrumented fusion the following day. Type 1 osteotomies were performed from T6-T12 to L3-S1 and an asymmetric PSO at L2. A temporary kickstand rod was used to distract across the concavity because the PSO was closed on the convexity. The patient achieved excellent clinical and radiographical results. CONCLUSION: When used in conjunction with appropriate osteotomies, the kickstand rod can aid in correction of severe coronal imbalance. Use of a temporary kickstand rod is technically easier and allows for correction of the main and fractional curves when used with an asymmetric PSO.