Open Versus Percutaneous Stabilization of Thoracolumbar Fractures: A Large Retrospective Analysis of Safety and Reoperation Rates.

BACKGROUND: Thoracolumbar fractures (TLF) requiring surgical intervention can be treated with either open or percutaneous stabilization, each with some distinct risks and benefits. There is insufficient evidence available to support one approach as superior. METHODS: Patients who underwent spinal fixation for TLF between 2008 and 2020 were reviewed. Patients with one or two levels of fracture treated with either open or percutaneous stabilization were included. Exclusion criteria were more than two levels of fracture, patients requiring corpectomy, stabilization constructs that crossed the cervicothoracic or lumbosacral junction, history of previous thoracolumbar fusion at the same level, spinal neoplasm, anterior or lateral fixation, and spinal infection. Demographic, operative, and clinical data were collected for all patients. RESULTS: 691 patients (377 open, 314 percutaneous) met the inclusion criteria. Patients in the percutaneous cohort sustained lower estimated blood loss (73 vs 334 ml; p< 0.001) and shorter length of surgery (114 vs. 151 minutes; p< 0.001). No differences were observed in the length of hospital stay or overall reoperation rates. Asymptomatic (7.0% vs 0.8%) and symptomatic (3.5% vs 0.5%) hardware removal was more common with the percutaneous cohort, while the incidence of revision surgery due to hardware failure requiring the extension of the construct (1.9% vs 5.8%) and infection (1.9% vs 6.4%) was greater in the open group. CONCLUSION: Percutaneous stabilization for TLF was associated with shorter operative time, less blood loss, lower infection rate, higher rates of elective hardware removal, and lower rates of hardware failure requiring extension of the construct compared to open stabilization.

Comparison of transforaminal and posterior lumbar interbody fusion outcomes in patients receiving a novel allograft versus rhBMP-2: a radiographic and patient-reported outcomes analysis.

OBJECTIVE: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been demonstrated to achieve the highest rates of arthrodesis in multilevel lumbar fusion but is also associated with possible perioperative morbidity. A novel allograft (OSTEOAMP) is a differentiated allograft that retains growth factors supporting bone healing. The authors sought to compare the clinical and radiographic outcomes of rhBMP-2 and the novel allograft in lumbar interbody arthrodesis to determine if the latter may be a safer and equally effective alternative to rhBMP-2 for single- and multilevel posterior or transforaminal lumbar interbody fusion (PLIF or TLIF). METHODS: Patients who underwent single- or multilevel TLIF or PLIF using either OSTEOAMP or rhBMP-2 at the authors' institution over a 2-year period were prospectively followed for 12 months. Healthcare utilization, safety measures, patient satisfaction, physical disability (measured on the Oswestry Disability Index [ODI]), back and leg pain (on the numeric rating scale [NRS]), quality of life (on the EQ-5D scale), and return to work (RTW) were prospectively recorded. For purposes of this study, this consecutive series was retrospectively analyzed and pseudarthrosis rates were assessed at 2 years of follow-up. All patients (100%) had both 12-month patient-reported outcome follow-up and 24-month clinical and radiographic follow-up. RESULTS: One thousand one hundred fifty-four patients (654 treated with OSTEOAMP, 500 with rhBMP-2) were prospectively enrolled in the institutional registry. After propensity score matching, there were no significant baseline differences between 330 novel allograft and 330 rhBMP-2 cases. Perioperative morbidity and 90-day hospital readmission (3.3% vs 2.4%, p = 0.485) did not significantly differ between the novel allograft and the rhBMP-2 cases. At the 2-year follow-up, symptomatic pseudarthrosis requiring revision surgery occurred in 8 patients (2.4%) with OSTEOAMP and 6 patients (1.8%) with rhBMP-2 (p = 0.589). The overall fusion rate at 2 years was similar between groups (p = 0.213). Both groups showed significant and equivalent improvement in patient-reported outcome measures (PROMs) from baseline to 12-month follow-up, with no significant difference in 1-year mean NRS leg pain score (2.5 vs 2.7), ODI (25 vs 26), quality-adjusted life years (0.73 vs 0.73), satisfaction (83% vs 80%), or RTW (6.6 vs 7 weeks). CONCLUSIONS: In the authors' institutional experience, OSTEOAMP is a clinically viable substitute for rhBMP-2 for single- and multilevel lumbar fusion. This novel allograft provides clinically effective arthrodesis and improvements in PROMs comparable to rhBMP-2 with a similar safety profile. Additional indications and outcome assessment in longitudinal studies are needed to further characterize this allogeneic graft.

Novel Approach to Difficult Spinal Reconstruction: Bilateral Simultaneous Rib and Iliac Crest Vascularized Bone Graft Spinoplastic Surgery.

Pseudoarthrosis is a severe complication of spinal fusion surgery with occurrence rates as high as 35%-40%. Current options of revision surgery to correct pseudoarthrosis frequently carry high failure rates and risk of developing junctional kyphosis. Pedicled vascularized bone grafts (VBGs) are an innovative approach to boost spinal fusion rates via improving structural integrity and increasing the delivery of blood to the donor site. This versatile technique can be performed at different spinal levels without additional skin incisions and with minimal added operative time. Here we present the first bilateral rib and iliac crest VBG spinoplastic surgery performed to augment spinal fusion in a 68-year-old woman with distal junctional kyphosis and severe positive sagittal balance with low back and neck pain and significant difficulty standing upright. The patient had history of multiple spinal operations with preoperative CT imaging demonstrating loosening and pull out of L3 and fracture of L2 screws. She underwent two-stage surgical treatment involving anterior lumbar interbody fusion L3-S1 followed by removal of hardware, T4 to pelvis fusion with L2-3 prone lateral interbody fusion, and T11-S1 posterior column osteotomies. The surgery was augmented by bilateral rib and iliac crest VBGs performed by plastic surgery. At three-month follow-up the patient demonstrated functional improvement, being able to maintain upright posture and walk; was satisfied with the result of the surgery; and demonstrated no graft-related complications. In conclusion, utilization of pedicled VBGs is a novel, promising approach to augment spinal surgery in high risk patients.

Mental health comorbidities in workers' compensation patients and the effect on pain, disability, quality of life, and return to work after lumbar spine surgery.

OBJECTIVE: The impact of mental health comorbidities on outcomes after lumbar spine surgery in workers' compensation (WC) patients has not been robustly explored. The goal of this study was to examine the impact of mental health comorbidities on pain, disability, quality of life, and return to work after lumbar spine surgery in WC patients. METHODS: A nationwide, prospective surgical outcomes registry (National Neurosurgery Quality Outcomes Database [N2QOD]) was queried for all patients who underwent 1- to 4-level lumbar decompression and/or fusion from 2012 to 2021. Patients were stratified on the basis of compensation status into non-WC (25,507) and WC (1018) cohorts. Baseline demographic data, perioperative safety data, and patient-reported outcome measures were compared between groups. The WC cohort was further subdivided on the basis of mental health status into patients with anxiety and depression (n = 107) and those without anxiety and depression (n = 911). Propensity matching was used to generate parity between these subgroups, generating 214 patients (107 pairs) for analysis. Perioperative safety, facility utilization, 1-year patient-reported outcomes (back and leg pain, disability, and quality of life), and return to work were measured as a function of WC and mental health comorbidity status. RESULTS: A total of 26,525 patients (25,507 non-WC and 1018 WC) who underwent 1- to 4-level lumbar spine surgery were reviewed. WC patients were younger, healthier (lower American Society of Anesthesiologists class), more likely to be minorities, less educated, and more likely to smoke and had greater baseline back pain, disability, and quality of life compared to non-WC patients. The prevalence of anxiety and depression was similar between groups (11%). WC patients had worse outcomes for all measures and lower rates of return to work compared to non-WC patients. WC patients with anxiety and depression demonstrated even greater disparities in all outcomes. After propensity matching, WC patients with anxiety and depression continued to demonstrate significantly worse outcomes in comparison to WC patients without anxiety and depression. CONCLUSIONS: Disparities in outcomes after lumbar spine surgery in WC patients are exacerbated in patients with anxiety and depression. WC patients with mental health comorbidities receive the least benefit from lumbar spine surgery and may represent the most vulnerable subset of patients with spine pathology. Addressing mental health comorbidities preoperatively may represent an opportunity for valuable resource allocation and surgical optimization in the WC population.

Patent bibliometrics in spinal deformity: the first bibliometric analysis of spinal deformity's technological literature.

PURPOSE: Bibliometric analyses have gained popularity for studying scientific literature, but their application to evaluate technological literature (patents) remains unexplored. We conducted a bibliometric analysis on the top 100 most-cited patents in scoliosis surgery. METHODS: Multiple databases were queried using The Lens to identify the top 100 scoliosis surgery patents, which were selected based on forward patent citations. These patents were then categorized into 8 groups based on technological descriptors and assessed based on various factors including earliest priority date, year issued, and expiration status. RESULTS: The top 100 most-cited patents included technology underlying anterolateral tethering and distraction systems (n = 11), posterior tethering and distraction systems (n = 23), posterior segmental bone anchor and rod engagement systems (n = 29), interbody devices (n = 10), biological and electrophysiological agents for scoliosis treatment and/or improved arthrodesis (n = 8), intraoperative arthroplasty devices (n = 5), orthotic devices (n = 12), and implantable devices for non-invasive, postoperative alterations of skeletal alignment (n = 2). Seventy-five patents were expired, 21 are still active, and 4 were listed as inactive. The late 1970s and early 2000s saw increased numbers of patent filings. Demonstrated trends showed no meaningful correlation between patent rank and earliest priority date (linear trendline y = 0.2648x - 477.27; R2 = 0.0114), while a very strong correlation was found between patent rank and citations per year (power trendline y = 118.82x--0.83; R2 = 0.8983). CONCLUSION: Patent bibliometric analyses in the field of spinal deformity surgery provide a means to assess past advancements, better understand what it takes to make a difference in the field, and to potentially facilitate the development of innovative technologies in the future. The method described is a reliable and reproducible technique for evaluating technological literature in our field.

Survey of United States neurosurgeons on firearm injury prevention.

OBJECTIVE: Firearm-related injuries and deaths are an endemic problem in the US, posing a burden on the healthcare system with significant social and economic consequences. As front-line care providers for these patients, neurosurgeons are both knowledgeable about these injuries and credible messengers in the public discussion of ways to reduce firearm injuries. The purpose of this study was to explore US-based neurosurgeons' views and behaviors regarding firearms to understand and define a potential role for neurosurgical organizations in advocacy efforts to reduce firearm death and injuries. METHODS: The authors conducted an anonymous survey of US neurosurgeons using the American Association of Neurological Surgeons (AANS) member database from April to June 2023. The 22-question survey included questions related to firearm ownership, personal views on firearms, and support for both general and policy-specific advocacy efforts to reduce firearm deaths and injuries. RESULTS: The survey response rate was 20.7%, with 1568 of the 7587 members invited completing the survey. The survey completion rate was 93.4%, with 1465 of the 1568 surveys completed and included in this analysis. The majority of respondents were male (raw: 81.7%; weighted 81.1%), White (raw: 69.7%; weighted 70.2%), and older than 50 years (raw: 56.2%; weighted: 54%). Most respondents reported treating patients with firearm injuries (raw: 83.3%; weighted: 82%), 85.5% (weighted: 85.1%) had used a firearm, and 42.4% (weighted: 41.5%) reported owning a firearm. Overall, 78.8% (weighted: 78.7%) of respondents felt that organized neurosurgery should participate in advocacy efforts. When examining individual policies, those that restrict the acquisition of firearms garnered the support of at least 65% of respondents, while nonrestrictive policies were supported by more than 75% of respondents. Free-text responses provided insight into both motivations for and objections to organizational advocacy. CONCLUSIONS: The majority of US-based neurosurgeons support involvement in advocacy efforts to reduce firearm deaths and injuries. Themes expressed by members both supporting and objecting to advocacy provide insight into approaches that could ensure broad support. Neurosurgical organizations such as the AANS and Congress of Neurological Surgeons may use the results of this survey to make informed decisions regarding involvement in advocacy efforts on behalf of their membership to lessen the burden of firearm injury in the US.

Effect of workers' compensation status on pain, disability, quality of life, and return to work after anterior cervical discectomy and fusion: a 1-year propensity score-matched analysis.

OBJECTIVE: Patients with workers' compensation (WC) claims are reported to demonstrate poorer surgical outcomes after lumbar spine surgery. However, outcomes after anterior cervical discectomy and fusion (ACDF) in WC patients remain debatable. The authors aimed to compare outcomes between a propensity score-matched population of WC and non-WC patients who underwent ACDF. METHODS: Patients who underwent 1- to 4-level ACDF were retrospectively reviewed from the prospectively maintained Quality Outcomes Database (QOD). After propensity score matching, 1-year patient satisfaction, physical disability (Neck Disability Index [NDI]), pain (visual analog scale [VAS]), EQ-5D, and return to work were compared between WC and non-WC cohorts. RESULTS: A total of 9957 patients were included (9610 non-WC and 347 WC patients). Patients in the WC cohort were significantly younger (50 ± 9.1 vs 56 ± 11.4 years, p < 0.001), less educated, and were more frequently male, non-Caucasian, and active smokers (29.1% vs 18.1%, p < 0.001), with greater baseline VAS and NDI scores and poorer quality of life (p < 0.001). One-year postoperative improvements in VAS, NDI, EQ-5D, and return-to-work rates and satisfaction were all significantly worse for WC compared with non-WC patients. After adjusting for baseline differences via propensity score matching, WC versus non-WC patients continued to demonstrate worse 3- and 12-month VAS neck pain and NDI (p = 0.010), satisfaction (χ2 = 4.03, p = 0.045), and delayed return to work (9.3 vs 5.7 weeks, p < 0.001). CONCLUSIONS: WC status was associated with greater 1-year residual disability and axial pain along with delayed return to work, without any difference in quality of life despite having fewer comorbidities and being a younger population. Further studies are needed to determine the societal impact that WC claims have on healthcare delivery in the setting of ACDF.

Expanding Clinician Access to High-Quality, Low-Cost Biomechanical Research: A Technical Report on the Carolina Neurosurgery and Spine Biomechanics Laboratory.

Spine biomechanical research helps us better understand the spine in physiologic and pathologic states and gives us a mechanism by which to evaluate surgical interventions, generate and evaluate models of spine pathologies, and develop novel, data-driven surgical strategies and devices. Access to a biomechanical testing laboratory is therefore potentially invaluable to those who specialize in treating spine pathologies. A number of barriers to access have precluded many clinicians from pursuing their biomechanical research interests, foremost among these is cost. The Carolina Neurosurgery and Spine Biomechanics Research Laboratory (CNSBL) was developed as a model of a low-cost, easy-to-access laboratory capable of generating high-quality data in tests of axial load, tension, torque, displacement, and pathological model testing. Our experience in developing this laboratory suggests that a large number of basic biomechanical research inquiries can be studied in a laboratory composed of less than $7500 USD of hardware. We hope that this model serves as a roadmap for any like-minded practitioners seeking broader access to biomechanical testing facilities.

Minimally Invasive Transforaminal Lumbar Interbody Fusion in the Ambulatory Surgery Center Versus Inpatient Setting: A 1-Year Comparative Effectiveness Analysis.

BACKGROUND: Ambulatory surgery centers (ASCs) have emerged as an alternative setting for surgical care as part of the national effort to lower health care costs. The literature regarding the safety of minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) in the ASC setting is limited to few small case series. OBJECTIVE: To assess the safety and efficacy of MIS TLIF performed in the ASC vs inpatient hospital setting. METHODS: A total of 775 patients prospectively enrolled in the Quality Outcomes Database undergoing single-level MIS TLIF at a single ASC (100) or the inpatient hospital setting (675) were compared. Propensity matching generated 200 patients for analysis (100 per cohort). Demographic data, resource utilization, patient-reported outcome measures (PROMs), and patient satisfaction were assessed. RESULTS: There were no significant differences regarding baseline demographic data, clinical history, or comorbidities after propensity matching. Only 1 patient required inpatient transfer from the ASC because of intractable pain. All other patients were discharged home within 23 hours of surgery. The rates of 90-day readmission (2.0%) and reoperation (0%) were equivalent between groups. Both groups experienced significant improvements in all PROMs (Oswestry Disability Index, EuroQol-5D, back pain, and leg pain) at 3 months that were maintained at 1 year. PROMs did not differ between groups at any time point. Patient satisfaction was similar between groups at 3 and 12 months after surgery. CONCLUSION: In carefully selected patients, MIS TLIF may be performed safely in the ASC setting with no statistically significant difference in safety or efficacy in comparison with the inpatient setting.

Anterior Cervical Discectomy and Fusion Versus Microendoscopic Posterior Cervical Foraminotomy for Unilateral Cervical Radiculopathy: A 1-Year Cost-Utility Analysis.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) and posterior cervical foraminotomy (PCF) are the most common surgical approaches for medically refractory cervical radiculopathy. Rigorous cost-effectiveness studies comparing ACDF and PCF are lacking. OBJECTIVE: To assess the cost-utility of ACDF vs PCF performed in the ambulatory surgery center setting for Medicare and privately insured patients at 1-year follow-up. METHODS: A total of 323 patients who underwent 1-level ACDF (201) or PCF (122) at a single ambulatory surgery center were compared. Propensity matching generated 110 pairs (220 patients) for analysis. Demographic data, resource utilization, patient-reported outcome measures, and quality-adjusted life-years were assessed. Direct costs (1-year resource use × unit costs based on Medicare national allowable payment amounts) and indirect costs (missed workdays × average US daily wage) were recorded. Incremental cost-effectiveness ratios were calculated. RESULTS: Perioperative safety, 90-day readmission, and 1-year reoperation rates were similar between groups. Both groups experienced significant improvements in all patient-reported outcome measures at 3 months that was maintained at 12 months. The ACDF cohort had a significantly higher preoperative Neck Disability Index and a significantly greater improvement in health-state utility (ie, quality-adjusted life-years gained) at 12 months. ACDF was associated with significantly higher total costs at 1 year for both Medicare ($11 744) and privately insured ($21 228) patients. The incremental cost-effectiveness ratio for ACDF was $184 654 and $333 774 for Medicare and privately insured patients, respectively, reflecting poor cost-utility. CONCLUSION: Single-level ACDF may not be cost-effective in comparison with PCF for surgical management of unilateral cervical radiculopathy.

Effect of workers' compensation status on pain, disability, quality of life, and return to work after lumbar spine surgery: a 1-year propensity-matched analysis.

OBJECTIVE: Workers' compensation (WC) and litigation have been shown to adversely impact prognoses in a vast range of health conditions. Low-back pain is currently the most frequent reason for WC claims. The objective of this study was to conduct the largest propensity-matched comparison of outcomes between patients with WC and non-WC status who underwent lumbar spinal decompression with and without fusion. METHODS: Complete data sets for patients who underwent 1- to 4-level lumbar spinal fusion or decompression alone were retrospectively retrieved from the Quality Outcomes Database (QOD), which included 1-year patient-reported outcomes from more than 200 hospital systems collected from 2012 to 2021. Population demographics, perioperative safety, facility utilization, patient satisfaction, disability, pain, EQ-5D quality of life, and return to work (RTW) rates were compared between cohorts for both subgroups. Statistical significance was set at p < 0.05. RESULTS: There were 29,652 patients included in the study. Laminectomy was performed in 16,939 with non-WC status and in 615 with WC, whereas fusion was performed in 11,767 with non-WC status and in 331 with WC. WC patients were more frequently male, a minority race, younger, less educated, more frequently a smoker, had a healthier American Society of Anesthesiologists grade, and with greater baseline visual analog scale (VAS) and Oswestry Disability Index (ODI) scores (p < 0.001). One-year postoperative improvements in VAS, ODI, quality-adjusted life years (QALYs), RTW rates, and satisfaction were all significantly worse for WC versus non-WC patients for both procedures. After adjusting for baseline differences via propensity matching, WC versus non-WC patients continued to demonstrate worse 3- and 12-month VAS and ODI scores, reduced 12-month QALY gain, and delayed RTW after both procedure types. CONCLUSIONS: WC status was associated with significantly greater residual disability and pain postoperatively, a lower quality of life, and delayed RTW. Utilizing resources to identify the negative influences on outcomes for WC patients may be valuable in preoperative optimization and could yield better outcomes in these patients.

Ten-Year Experience of Skip Anterior Cervical Corpectomy and Fusion.

BACKGROUND: Anterior cervical corpectomy and fusion (ACCF) is often required to adequately decompress the spinal cord in patients with multilevel cervical spondylosis. Unfortunately, multilevel corpectomy constructs have high rates of early failure and frequently require supplemental posterior fixation. First described in 2003, skip ACCF (sACCF) is defined by corpectomies above and below an intervening vertebral body, which serves as an additional fixation point to augment biomechanical stability. Subsequent studies report high fusion rates and low construct failure rates secondary to superior biomechanical stability. OBJECTIVE: The goal of this study was to demonstrate the safety and efficacy of sACCF in the largest series published to date. METHODS: This study was a retrospective case series of all patients who underwent sACCF at a single institution over a 10-year period. Standard demographic and perioperative data were collected. Outcome data included immediate postoperative complications, long-term reoperation, and pre- and postoperative radiographic parameters. RESULTS: Forty-five patients underwent sACCF: 42 at C4-C6 and 3 at C5-C7. Mean age was 57.5 years. More than half (64.4%) of patients were smokers. Almost all patients were discharged home, the vast majority (82.2%) within 3 days of surgery. Five patients (11.1%) developed complications during the index hospitalization: 2 C5 palsies and 3 medical complications. Three patients (6.7%) developed instrumentation failure requiring anterior revision and supplemental posterior fixation. There were statistically significant increases in C1-C7 (47.8 vs 41.1, P < 0.001) and C2-C7 lordosis (11.1 vs 5.0, P < 0.001) on postoperative radiographs compared with preoperative imaging. Average follow-up was 21.1 months. CONCLUSION: sACCF can be performed safely with complication rates similar to those reported for multilevel anterior cervical discectomy and fusion or adjacent segment ACCF. It should be considered for patients with multilevel cervical pathology for whom an anterior approach is favored. CLINICAL RELEVANCE: sACCF is an effective surgical technique for multilevel cervical decompression and correction of cervical alignment.

Anterior Cervical Discectomy and Fusion in the Ambulatory Surgery Center Versus Inpatient Setting: One-Year Cost-Utility Analysis.

STUDY DESIGN: Retrospective analysis of prospectively collected data. OBJECTIVE: Assess the cost-utility of anterior cervical discectomy and fusion (ACDF) performed in the ambulatory surgery center (ASC) versus inpatient hospital setting for Medicare and privately insured patients at one-year follow-up. SUMMARY OF BACKGROUND DATA: Outpatient ACDF has gained popularity due to improved safety and reduced costs. Formal cost-utility studies for ambulatory versus inpatient ACDF are lacking, precluding an accurate assessment of cost-effectiveness. MATERIALS AND METHODS: A total of 6504 patients enrolled in the Quality Outcomes Database (QOD) undergoing one-level to two-level ACDF at a single ASC (520) or the inpatient hospital setting (5984) were compared. Propensity matching generated 748 patients for analysis (374 per cohort). Demographic data, resource utilization, patient-reported outcome measures, and quality-adjusted life-years (QALYs) were assessed. Direct costs (1-year resource use×unit costs based on Medicare national allowable payment amounts) and indirect costs (missed workdays×average US daily wage) were recorded. Incremental cost-effectiveness ratios were calculated. RESULTS: Complication rates and improvements in patient-reported outcome measures and QALYs were similar between groups. Ambulatory ACDF was associated with significantly lower total costs at 1 year for Medicare ($5879.46) and privately insured ($12,873.97) patients, respectively. The incremental cost-effectiveness ratios for inpatient ACDF was $3,674,662 and $8,046,231 for Medicare and privately insured patients, respectively, reflecting unacceptably poor cost-utility. CONCLUSION: Inpatient ACDF is associated with significant increases in total costs compared to the ASC setting without a safety, outcome, or QALY benefit. The ASC setting is a dominant option from a health economy perspective for first-time one-l to two-level ACDF in select patients compared to the inpatient hospital setting.

Review: Patent Bibliometrics in Cranial Neurosurgery: The First Bibliometric Analysis of Neurosurgery's Technological Literature.

BACKGROUND: Bibliometric analyses of the scientific literature have grown increasingly popular in the past few decades. However, patent bibliometric studies, evaluation of technological literature, have not yet been applied in neurosurgery. OBJECTIVE: To perform a pilot patent bibliometric analysis of the top 100 most cited patents in cranial neurosurgery. METHODS: The Lens was used to query multiple databases, to select the top 100 cranial neurosurgical patents based upon forward patent citations. These were organized into 9 categories based on technological descriptors and were evaluated based on the earliest priority date, year issued, and expiration status, among others. RESULTS: The top 100 most cited patents included technology underlying 3D navigation (n = 31), pharmacology and implants (n = 20), vascular occlusion (n = 5), craniotomy closure (n = 9), focal lesioning and tissue resection (n = 8), brain and systemic cooling (n = 5), neuroendoscopy (n = 8), neuromonitoring and stimulation (6), and technologies improving surgeon performance (n = 8). Ninety-six patents were filed in the United States, 72 were expired, 19 are still active, and 9 were listed as inactive. The highest number of patents was applied for from the mid-1990s to the mid-2000s. Demonstrated trends showed no meaningful correlation between patent rank and earliest priority date (linear trendline y = 0.7107 x -1367.5; R2 = 0.0671), while a very strong correlation was found between patent rank and citations per year (power trendline y = 127.93 x -1.094; R2 = 0.8579). CONCLUSIONS: Patent bibliometrics allow evaluation of neurosurgical advancements from the past and enable subsequent development of cutting-edge technology in the future. The described method is a reproducible and reliable technique for evaluating our field's patent literature.

Technical Feasibility of Subaxial Cervical Pedicle Screws for Distal Anchoring of Occipitocervical Fixation Constructs in the Mid-Cervical Spine: Early Clinical Experience.

Occipitocervical fixation and fusion (OCF) is performed for patients who have destabilizing traumatic injuries or pathologies affecting the complex bony and ligamentous structures of the occipitoatlantal and atlantoaxial joint structures. Distal fixation failure and pseudoarthrosis are known risks of these constructs, especially for those constructs ending in the mid-cervical spine. We present the technical feasibility of using cervical pedicle screws (CPSs) as distal fixation anchors to strengthen OCF constructs ending in the mid-cervical spine and present a case series describing our early clinical experience with this technique. We used a freehand technique to place subaxial pedicle screws in the mid-cervical spine as the distal fixation point in OCF constructs. This technique involves performing a laminotomy to provide direct visualization of the pedicle borders to safely guide freehand pedicle screw placement. Our early clinical experience with this technique is presented. Three patients received OCF constructs ending in the mid-cervical subaxial spine between C3 and C6. CPSs were placed at the distal vertebra in each construct. Stable instrumentation and arthrodesis were confirmed postoperatively in all patients. This freehand technique uses direct visualization of the pedicle to aid in safe and accurate subaxial pedicle screw placement. CPS placement is clinically feasible and increases the robustness of OCF constructs in appropriately selected patients. Larger case series are needed to further validate the safety and effectiveness of this technique.

Establishing a Reference Procedure Length for Anterior Cervical Fusions: The Role for Standards in Surgical Process Improvement.

Surgical process improvement strategies are increasingly being applied to specific procedures to improve value. A critical step in any process improvement strategy is the identification of performance benchmarks. Procedure length is a performance benchmark for anterior cervical discectomy and fusion (ACDF) procedures; therefore, we sought to establish reference procedure lengths for 1-level, 2-level, and 3-level ACDFs at both teaching and non-teaching institutions and to describe methods for using this information to advance surgical process improvement initiatives. We performed a retrospective analysis of consecutive ACDFs performed at a resident teaching institution (RT) and a non-teaching institution (NT) for all 1-level, 2-level, and 3-level ACDFs. Mean case lengths and patient outcomes were calculated for individual surgeons and institutions. After limiting cases to 1-level, 2-level, and 3-level ACDFs and applying all exclusion criteria, 991 cases at the RT institution and 131 cases at the NT institution (a total of 1122 cases) were available for analysis. The mean (SD) procedure length for 1-level, 2-level, and 3-level ACDFs at the RT versus NT institutions were 121.9 min (36.3 min) and 73.6 min (29.7 min) (p<0.001), 172.7 min (44.8 min) and 112.0 min (43.0 min) (p<0.001), and 218.3 min (54.9 min) and 167.6 min (54.2 min) (p<0.001), respectively. Thirty-day outcomes were the same between institutions, except that the RT institution had a shorter mean hospital length of stay for 2-level ACDFs (1.6 days versus 2.9 days, p=0.001). This study is the first to attempt to establish a standard reference procedure length for 1-level, 2-level, and 3-level ACDFs. These data can guide efforts in surgical process improvement.

Posterior Fossa Hemorrhage Following the Use of Low-Molecular-Weight Heparin: Lessons Learned and Recommendations for the Treatment and Prophylaxis of Postoperative Venous Thromboembolism.

Introduction Venous thromboembolism (VTE) is the most common preventable cause of morbidity and mortality among neurosurgery patients. Several studies have concluded that the use of chemical prophylaxis among patients undergoing a craniotomy reduces the incidence of VTE, and it is presumed to be safe. However, these studies do not differentiate between a supratentorial and posterior fossa craniotomy. Furthermore, the prophylactic or therapeutic use of low-molecular-weight heparin (LMWH) has been reported to increase the risk of intracranial hemorrhage. In this study, we describe the clinical details and outcomes for all patients who underwent posterior fossa craniotomy and developed posterior fossa hemorrhage secondary to postoperative use of LMWH during the study period. We also propose recommendations pertaining to postoperative heparin use after posterior fossa surgeries. Methods Data were retrospectively collected for patients presenting with posterior fossa hemorrhage following anticoagulant use among those who previously underwent posterior fossa craniotomy by the senior author (R.W.P.) from January 1, 2011, through December 31, 2018. Results We identified five patients who experienced postoperative hemorrhage while receiving LMWH in the initial setting of posterior fossa craniotomy. After hemorrhaging, four patients had low Glasgow Outcome Scale (GOS) scores (≤3) and failed to return to their baseline neurological status. These four patients had a Glasgow Coma Scale (GCS) score of 15/15 in the immediate postoperative period and received heparin within 72 hours of surgery. Conclusions Based on our findings, there is a possible association between the increased risk of hemorrhage and the early postoperative use of LMWH. The debilitating outcomes among the majority of these patients warrant the cautious use and further investigation of postoperative LMWH to appropriately quantify the risk. Further comparative studies with a larger sample size are required to provide insight into the pathophysiology of our findings.

Hospital use following anterior cervical discectomy and fusion.

Most existing anterior cervical discectomy and fusion (ACDF) outcome studies omit emergency department (ED) use. To our knowledge, this study on ED use following ACDF surgery is the first to use a direct patient chart review and the first to include revision patients, 1-5 levels of ACDFs, and performance of corpectomy in the analysis. This study examines the frequency and basis of hospital service use within 30 days of ACDF surgery, specifically ED visits, hospital readmissions, and returns to the operating room. A retrospective chart review was performed for 1273 consecutive patients who underwent ACDF surgery at one institution from July 2013 to June 2016. Of the 1273 patients with ACDF, 97 (7.6%) presented to the ED within 30 days after surgery. Of 43 patients with revision ACDF, 9 (20.9%) returned to the ED, compared with 88 (7.2%) of 1230 patients with primary ACDF (P = 0.001). Of the 111 ED visits by 97 patients, 40 (36%) were for cervicalgia, 13 (12%) were for dysphagia, 8 (7%) were for trauma, 7 (6%) were for nausea, 4 (4%) were for medication refill, 3 (3%) were for dehiscence, 3 (3%) were for pneumonia, and 3 (3%) were for urinary tract infection. Of the ED presentations, 8 (7%) occurred during the first 2 days after surgery, and 46 (41%) occurred within the first postoperative week.

Vascularized Occipital Bone Grafting: Indications, Techniques, Clinical Outcomes, and Alternatives.

Successful arthrodesis at the craniocervical junction and atlantoaxial joint can be more challenging than in other segments of the cervical spine. Different techniques for spinal fixation in this region have been well described, along with auxiliary methods to improve fusion rates. The occipital vascularized bone graft is a novel technique that can be used to augment bony arthrodesis in the supra-axial cervical spine. It provides the benefits of a vascularized autologous graft, such as accelerated healing, earlier fusion, and increased strength. This technique can be learned with relative ease and may be particularly helpful in cases with high risk of nonunion or pseudoarthrosis in the upper cervical spine.

Vascularized Scapular Bone Grafting: Indications, Techniques, Clinical Outcomes, and Alternatives.

Spinal fusion can be challenging to obtain in patients with complex spinal pathology. Medial scapular vascularized bone grafts (S-VBGs) are a novel approach to supplement cervicothoracic arthrodesis in patients at high risk of failed spinal fusion. In this article, we discuss the benefits of using VBGs compared with both nonvascularized bone grafts and free vascularized bone flaps and the surgical technique, feasibility, and limitations specific to the S-VBG.