Lumbar surgical drains do not increase the risk of infections in patients undergoing spine surgery.

PURPOSE: The aim of this study was to characterize if the use of surgical drains or length of drain placement following spine surgery increases the risk of post-operative infection. METHODS: Records of patients undergoing elective spinal surgery at a tertiary care center were collected between May 5, 2016 and August 16, 2018. Pre-operative baseline characteristics were recorded including patient's demographics and comorbidities. Intraoperative procedure information was documented related to procedure type, blood loss, and antibiotics used. Following surgery, patients were then further subdivided into two groups: patients who were discharged with a spinal surgical site drain and patients who did not receive a drain. Post-operative surgical variables included length of stay (LOS), drain length, number of antibiotics given, and type of post-operative infection. Univariate and multivariate statistical analysis was conducted. RESULTS: A total of 671 patients were included in the current study, 386 (57.5%) with and 285 (42.5%) without the drain. The overall infection rate was 5.7% with 6.22% among patients with the drain compared to 4.91% in patients without drain. The univariate analysis identified the following variables to be significantly associated with the infection: total number of surgical levels, spinal region, blood loss, redosing of antibiotics, length of stay, length of drain placement, and number of antibiotics (P < 0.05). However, the multivariate analysis none of the predictors was significant. CONCLUSIONS: The current study shows that the placement of drain does not increase rate of infection, irrespective of levels, length of surgery, or approach.

Trends analysis of surgical procedures for cervical degenerative disc disease and myelopathy in patients with tobacco use disorder.

PURPOSE: This study defined the incidence and trends of surgeries performed for patients with cervical disc degeneration with and without tobacco use disorder (TUD). METHODS: This study utilized the Humana Inc. database between 2007 and 2013 to identify patients with cervical disc degeneration with or without myelopathy. International Classification of Diseases, ninth revision (ICD-9) and Current Procedural Terminology (CPT) codes determined the initial diagnosis of disc degeneration, myelopathy status and TUD, whether patients received surgery, and TUD status at surgery. RESULTS: The prevalence of disc degeneration with myelopathy increased by 32.8% between 2007 and 2013, while disc disease with myelopathy and TUD increased by 91.6%. For patients without myelopathy, the prevalence of disc degeneration alone increased by 65.4%, and disc degeneration with myelopathy increased by 148.7%. Of myelopathy patients, 1717 (6.4%) had TUD and 1024 (59.6%) received surgery, compared to 6508 patients without TUD (26.1%). For patients without myelopathy, 11,337 (3.5%) had TUD and 787 (6.9%) underwent surgery, compared to 9716 patients (3%) without TUD. Of surgical patients, 781 (76.3%) with myelopathy and TUD still had a TUD diagnosis at surgery, and 542 (68.9%) of patients without myelopathy still had a TUD diagnosis at surgery. CONCLUSIONS: The prevalence of degenerative disc disease and TUD has increased more than disc disease alone. Patients with TUD were more likely to get surgery, and to have surgeries earlier than patients without TUD. Patients with TUD at the time of the diagnosis of their disc degeneration likely still had a TUD diagnosis at the time of surgery.

A Portable Shoulder-Mounted Camera System for Surgical Education in Spine Surgery.

The past several years have demonstrated an increased recognition of operative videos as an important adjunct for resident education. Currently lacking, however, are effective methods to record video for the purposes of illustrating the techniques of minimally invasive (MIS) and complex spine surgery. We describe here our experiences developing and using a shoulder-mounted camera system for recording surgical video. Our requirements for an effective camera system included wireless portability to allow for movement around the operating room, camera mount location for comfort and loupes/headlight usage, battery life for long operative days, and sterile control of on/off recording. With this in mind, we created a shoulder-mounted camera system utilizing a GoPro™ HERO3+, its Smart Remote (GoPro, Inc., San Mateo, California), a high-capacity external battery pack, and a commercially available shoulder-mount harness. This shoulder-mounted system was more comfortable to wear for long periods of time in comparison to existing head-mounted and loupe-mounted systems. Without requiring any wired connections, the surgeon was free to move around the room as needed. Over the past several years, we have recorded numerous MIS and complex spine surgeries for the purposes of surgical video creation for resident education. Surgical videos serve as a platform to distribute important operative nuances in rich multimedia. Effective and practical camera system setups are needed to encourage the continued creation of videos to illustrate the surgical maneuvers in minimally invasive and complex spinal surgery. We describe here a novel portable shoulder-mounted camera system setup specifically designed to be worn and used for long periods of time in the operating room.

Complications associated with the Dynesys dynamic stabilization system: a comprehensive review of the literature.

The Dynesys dynamic stabilization system is an alternative to rigid instrumentation and fusion for the treatment of lumbar degenerative disease. Although many outcomes studies have shown good results, currently lacking is a comprehensive report on complications associated with this system, especially in terms of how it compares with reported complication rates of fusion. For the present study, the authors reviewed the literature to find all studies involving the Dynesys dynamic stabilization system that reported complications or adverse events. Twenty-one studies were included for a total of 1166 patients with a mean age of 55.5 years (range 39-71 years) and a mean follow-up period of 33.7 months (range 12.0-81.6 months). Analysis of these studies demonstrated a surgical-site infection rate of 4.3%, pedicle screw loosening rate of 11.7%, pedicle screw fracture rate of 1.6%, and adjacent-segment disease (ASD) rate of 7.0%. Of studies reporting revision surgeries, 11.3% of patients underwent a reoperation. Of patients who developed ASD, 40.6% underwent a reoperation for treatment. The Dynesys dynamic stabilization system appears to have a fairly similar complication-rate profile compared with published literature on lumbar fusion, and is associated with a slightly lower incidence of ASD.

Anatomic surgical management of chronic low back pain.

OBJECTIVE: To review spine surgery management strategies for patients with chronic low back pain (CLBP) that has failed to respond to all nonsurgical treatment options. MATERIALS AND METHODS: Literature review was conducted for spine surgery in the treatment of CLBP without compressive anatomical disease. The main diagnosis identified was degenerated disc disease, and surgical options targeted for the treatment of CLBP were reviewed. RESULTS: The history of current spine intervention for CLBP was reviewed, including various surgical options. Surgical treatment options for patients with CLBP include lumbar fusion, lumbar disc arthroplasty, and dynamic stabilization. Lumbar fusion remains the most frequent spine surgery performed for CLBP, but questions still exist regarding its efficacy in comparison with conservative care or interventional pain management. Lumbar disc arthroplasty and dynamic stabilization can both be considered only for select patients with CLBP, and their uses are currently limited. CONCLUSION: Despite the number of spine surgeries that have been performed for CLBP, the surgical outcome still remains questionable. Until a precise identification of the cause of CLBP in any given patient can be precisely determined, surgical solutions will continue to be less than optimal.

The impact of enhanced recovery after surgery (ERAS) on opioid consumption and postoperative pain levels in elective spine surgery.

OBJECTIVE: Enhanced Recovery after Surgery (ERAS) protocols were developed to counteract the adverse effects of the surgical stress response, aiming for quicker postoperative recovery. Initially applied in abdominal surgeries, ERAS principles have extended to orthopedic spine surgery, but research in this area is still in its infancy. The current study investigated the impact of ERAS on postoperative pain and opioid consumption in elective spine surgeries. METHODS: A single-center retrospective study of patients undergoing elective spine surgery from May 2019 to July 2020. Patients were categorized into two groups: those enrolled in the ERAS pathway and those adhering to traditional surgical protocols. Data on demographics, comorbidities, length of stay (LOS), surgical procedures, and postoperative outcomes were collected. Postoperative pain was evaluated using the Numerical Rating Scale (NRS), while opioid utilization was quantified in morphine milligram equivalents (MME). NRS and MME were averaged for each patient across all days under observation. Differences in outcomes between groups (ERAS vs. treatment as usual) were tested using the Wilcoxon rank sum test for continuous variables and Pearson's or Fisher's exact tests for categorical variables. RESULTS: The median of patient's mean daily NRS scores for postoperative pain were not statistically significantly different between groups (median = 5.55 (ERAS) and 5.28 (non-ERAS), p=.2). Additionally, the median of patients' mean daily levels of MME were similar between groups (median = 17.24 (ERAS) and 16.44 (non-ERAS), p=.3) ERAS patients experienced notably shorter LOS (median=2 days) than their non-ERAS counterparts (median=3 days, p=.001). The effect of ERAS was moderated by whether the patient had ACDF surgery. ERAS (vs. non-ERAS) patients who had ACDF surgery had 1.64 lower average NRS (p=.006). ERAS (vs. non-ERAS) patients who had a different surgery had 0.72 higher average NRS (p=.02) but had almost half the length of stay, on average (p<.001). CONCLUSIONS: The current study underscores the dynamic nature of ERAS protocols within the realm of spine surgery. While ERAS demonstrates advantages such as reduced LOS and improved patient-reported outcomes, it requires careful implementation and customization to address the specific demands of each surgical discipline. The potential to expedite recovery, optimize resource utilization, and enhance patient satisfaction cannot be overstated. However, the fine balance between achieving these benefits and ensuring comprehensive patient care, especially in the context of postoperative pain management, must be maintained. As ERAS continues to evolve and find its place in diverse surgical domains, it is crucial for healthcare providers to remain attentive to patient needs, adapting ERAS protocols to suit individual patient populations and surgical contexts.

Top 25 Most Cited Articles on Intraoperative Computer Tomography-Guided Navigation in Spine Surgery.

BACKGROUND: In recent years, the use of intraoperative computer tomography-guided (CT-guided) navigation has gained significant popularity among health care providers who perform minimally invasive spine surgery. This review aims to identify and analyze trends in the literature related to the widespread adoption of CT-guided navigation in spine surgery, emphasizing the shift from conventional fluoroscopy-based techniques to CT-guided navigation. METHODS: Articles pertaining to this study were identified via a database review and were hierarchically organized based on the number of citations. An "advanced document search" was performed on September 28th, 2022, utilizing Boolean search operator terms. The 25 most referenced articles were combined into a primary list after sorting results in descending order based on the total number of citations. RESULTS: The "Top 25" list for intraoperative CT-guided navigation in spine surgery cumulatively received a total of 2742 citations, with an average of 12 new citations annually. The number of citations ranged from 246 for the most cited article to 60 for the 25th most cited article. The most cited article was a paper by Siewerdsen et al., with 246 total citations, averaging 15 new citations per year. CONCLUSIONS: Intraoperative CT-guided navigation is 1 of many technological advances that is used to increase surgical accuracy, and it has become an increasingly popular alternative to conventional fluoroscopy-based techniques. Given the increasing adoption of intraoperative CT-guided navigation in spine surgery, this review provides impactful evidence for its utility in spine surgery.

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.

Perioperative Complications of Surgery for Degenerative Cervical Myelopathy: A Comparison Between 3 Procedures.

STUDY DESIGN: Retrospective comparative study. OBJECTIVES: To compare the perioperative complications of propensity score-matched cohorts of patients with degenerative cervical myelopathy (DCM), who were treated with anterior cervical discectomy and fusion (ACDF), posterior laminectomy with fusion, or laminoplasty. METHODS: The Humana PearlDiver Patient Record Database was queried using the International Classification of Diseases (ICD-9 and ICD-10) and the Current Procedural Terminology (CPT) codes. Propensity score-matched analysis was done using multiple Chi-squared tests with Bonferroni correction of the significance level. RESULTS: Cohorts of 11,790 patients who had ACDF, 2,257 patients who had posterior laminectomy with fusion, and 477 patients who had laminoplasty, were identified. After propensity score matching, all the 3 groups included 464 patients. The incidence of dysphagia increased significantly following ACDF compared to laminoplasty, P < 0.001, and in laminectomy with fusion compared to laminoplasty, P < 0.001. The incidence of new-onset cervicalgia was higher in ACDF compared to laminoplasty, P = 0.005, and in laminectomy with fusion compared to laminoplasty, P = 0.004. The incidence of limb paralysis increased significantly in laminectomy with fusion compared to ACDF, P = 0.002. The revision rate at 1 year increased significantly in laminectomy with fusion compared to laminoplasty, P < 0.001, and in ACDF compared to laminoplasty, P < 0.001. CONCLUSIONS: The incidence of dysphagia following laminectomy with fusion was not different compared to ACDF. Postoperative new-onset cervicalgia and revisions were least common in laminoplasty. The highest rate of postoperative limb paralysis was noticed in laminectomy with fusion.

A Tale of Two Institutions: COVID-19 Positive Rates in Asymptomatic Patients Pre-Screened for Spine Procedures and Surgeries in Los Angeles, California.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The coronavirus disease (COVID-19), caused by the severe respiratory syndrome coronavirus 2 (SARS-CoV-2), has created an unprecedented global public health emergency. The aim of the current study was to report on COVID-19 rates in an asymptomatic population prior to undergoing spine procedures or surgeries at two large Los Angeles healthcare systems. METHODS: Elective spine procedures and surgeries from May 1, 2020 to January 31, 2021 were included. Results from SARS-CoV-2 virus RT-PCR nasopharyngeal testing within 72 hours prior to elective spine procedures were recorded. Los Angeles County COVID-19 rates were calculated using data sets from Los Angeles County Department of Public Health. Chi-squared test and Stata/IC were used for statistical analysis. RESULTS: A total of 4,062 spine procedures and surgeries were scheduled during this time period. Of these, 4,043 procedures and surgeries were performed, with a total of 19 patients testing positive. Nine positive patients were from UCLA, and 10 from USC. The overall rate of positive tests was low at .47% and reflected similarities with Los Angeles County COVID-19 rates over time. CONCLUSIONS: The current study shows that pre-procedure COVID-19 testing rates remains very low, and follows similar patterns of community rates. While pre-procedure testing increases the safety of elective procedures, universal COVID-19 pre-screening adds an additional barrier to receiving care for patients and increases cost of delivering care. A combination of pre-screening, pre-procedure self-quarantine, and consideration of overall community COVID-19 positivity rates should be further studied.

Using machine learning and big data for the prediction of venous thromboembolic events after spine surgery: A single-center retrospective analysis of multiple models on a cohort of 6869 patients.

Objective: Venous thromboembolic event (VTE) after spine surgery is a rare but potentially devastating complication. With the advent of machine learning, an opportunity exists for more accurate prediction of such events to aid in prevention and treatment. Methods: Seven models were screened using 108 database variables and 62 preoperative variables. These models included deep neural network (DNN), DNN with synthetic minority oversampling technique (SMOTE), logistic regression, ridge regression, lasso regression, simple linear regression, and gradient boosting classifier. Relevant metrics were compared between each model. The top four models were selected based on area under the receiver operator curve; these models included DNN with SMOTE, linear regression, lasso regression, and ridge regression. Separate random sampling of each model was performed 1000 additional independent times using a randomly generated training/testing distribution. Variable weights and magnitudes were analyzed after sampling. Results: Using all patient-related variables, DNN using SMOTE was the top-performing model in predicting postoperative VTE after spinal surgery (area under the curve [AUC] =0.904), followed by lasso regression (AUC = 0.894), ridge regression (AUC = 0.873), and linear regression (AUC = 0.864). When analyzing a subset of only preoperative variables, the top-performing models were lasso regression (AUC = 0.865) and DNN with SMOTE (AUC = 0.864), both of which outperform any currently published models. Main model contributions relied heavily on variables associated with history of thromboembolic events, length of surgical/anesthetic time, and use of postoperative chemoprophylaxis. Conclusions: The current study provides promise toward machine learning methods geared toward predicting postoperative complications after spine surgery. Further study is needed in order to best quantify and model real-world risk for such events.

The performance of frailty in predictive modeling of short-term outcomes in the surgical management of metastatic tumors to the spine.

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.

Tobacco Use Is Associated With Increased 90-Day Readmission Among Patients Undergoing Surgery for Degenerative Spine Disease.

STUDY DESIGN: Retrospective database study. OBJECTIVE: Tobacco use is associated with complications after surgical procedures, including poor wound healing, surgical site infections, and cardiovascular events. We used the Nationwide Readmissions Database (NRD) to determine if tobacco use is associated with increased 30- and 90-day readmission among patients undergoing surgery for degenerative spine disorders. METHODS: Patients who underwent elective spine surgery were identified in the NRD from 2010 to 2014. The study population included patients with degenerative spine disorders treated with discectomy, fusion, or decompression. Descriptive and multivariate logistic regression analyses were performed to identify patient and hospital factors associated with 30- and 90-day readmission, with significance set at P value <.001. RESULTS: Within 30 days, 4.8% of patients were readmitted at a median time of 9 days. The most common reasons for 30-day readmission were postoperative infection (12.5%), septicemia (3.5%), and postoperative pain (3.0%). Within 90 days, 7.3% were readmitted at a median time of 18 days. The most common reasons for 90-day readmission were postoperative infection (9.6%), septicemia (3.5%), and pneumonia (2.3%). After adjustment for patient and hospital characteristics, tobacco use was independently associated with readmission at 90 days (odds ratio 1.05, 95% confidence interval 1.03-1.07, P < .0001) but not 30 days (odds ratio 1.02, 95% confidence interval 1.00-1.05, P = .045). CONCLUSIONS: Tobacco use is associated with readmission within 90 days after cervical and thoracolumbar spine surgery for degenerative disease. Tobacco use is a known risk factor for adverse health events and therefore should be considered when selecting patients for spine surgery.

Approach-related complications after decompression for cervical ossification of the posterior longitudinal ligament.

The surgical management of compressive cervical ossification of the posterior longitudinal ligament (OPLL) can be challenging. Traditionally, approach indications for decompression of cervical spondylotic myelopathy have been used. However, the postoperative complication profile after cervical OPLL decompression is unique and may require an alternative approach paradigm. The authors review the literature on approach-related OPLL complications and suggest a management strategy for patients with single- or multiple-segment OPLL with or without greater than 50% canal stenosis.

Management of ossification of the posterior longitudinal ligament of the thoracic spine.

The management of thoracic ossification of the posterior longitudinal ligament has been studied by many spinal surgeons. Indications for operative intervention include progressive radiculopathy, myelopathy, and neurological deterioration. The ideal surgery for decompression remains highly debatable as various methods of surgical treatment of ossification of the posterior longitudinal ligament have been devised. Although numerous modifications to the 3 main approaches have been identified (anterior, posterior, or lateral), the indication for each depends on the nature of compression, the morphology of the lesion, the level of the compression, the structural alignment of the spine, and the neurological status of the patient. The authors discuss treatment techniques for thoracic ossification of the posterior longitudinal ligament, cite case examples from a single institution, and review the literature.

Complications and outcomes after spinal deformity surgery in the elderly: review of the existing literature and future directions.

OBJECT: The elderly population (age > 60 years) is the fastest-growing age group in the US. Spinal deformity is a major problem affecting the elderly and, therefore, the demand for surgery for spinal deformity is becoming increasingly prevalent in elderly patients. Much of the literature on surgery for adult deformity focuses on patients who are younger than 60 years, and therefore there is limited information about the complications and outcomes of surgery in the elderly population. In this study, the authors undertook a review of the literature on spinal deformity surgery in patients older than 60 years. The authors discuss their analysis with a focus on outcomes, complications, discrepancies between individual studies, and strategies for complication avoidance. METHODS: A systematic review of the MEDLINE and PubMed databases was performed to identify articles published from 1950 to the present using the following key words: "adult scoliosis surgery" and "adult spine deformity surgery." Exclusion criteria included patient age younger than 60 years. Data on major Oswestry Disability Index (ODI) scores, visual analog scale (VAS) scores, patient-reported outcomes, and complications were recorded. RESULTS: Twenty-two articles were obtained and are included in this review. The mean age was 74.2 years, and the mean follow-up period was 3 years. The mean preoperative ODI was 48.6, and the mean postoperative reduction in ODI was 24.1. The mean preoperative VAS score was 7.7 with a mean postoperative decrease of 5.2. There were 311 reported complications for 815 patients (38%) and 5 deaths for 659 patients (< 1%). CONCLUSIONS: Elderly patient outcomes were inconsistent in the published studies. Overall, most elderly patients obtained favorable outcomes with low operative mortality following surgery for adult spinal deformity.

Minimally invasive lateral lumbar interbody fusion and transpsoas approach-related morbidity.

OBJECT: Recently, the minimally invasive, lateral retroperitoneal, transpsoas approach to the thoracolumbar spinal column has been described by various authors. This is known as the minimally invasive lateral lumbar interbody fusion. The purpose of this study is to elucidate the approach-related morbidity associated with the minimally invasive transpsoas approach to the lumbar spine. To date, there have been only a couple of reports regarding the morbidity of the transpsoas muscle approach. METHODS: A nonrandomized, prospective study utilizing a self-reported patient questionnaire was conducted between January 2006 and June 2008 at Northwestern University. Data were collected in 53 patients with a follow-up period ranging from 6 months to 3.5 years. Only 2 patients were lost to follow-up. RESULTS: Thirty-six percent (19 of 53) of patients reported subjective hip flexor weakness, 25% (13 of 53) anterior thigh numbness, and 23% (12 of 53) anterior thigh pain. However, 84% of the 19 patients reported complete resolution of their subjective hip flexor weakness by 6 months, and most experienced improved strength by 8 weeks. Of those reporting anterior thigh numbness and pain, 69% and 75% improved to their baseline function by the 6-month follow-up evaluations, respectively. All patients with self-reported subjective hip flexor weakness underwent examinations during subsequent clinic visits after surgery; however, these examinations did not confirm a motor deficit less than Grade 5. Subset analysis showed that the L3-4 and L4-5 levels were most often affected. CONCLUSIONS: The minimally invasive, transpsoas muscle approach to the lumbar spine has a number of advantages. The data show that a percentage of the patients undergoing the transpsoas approach will have temporary sensory and motor symptoms related to this approach. The majority of the symptoms are thought to be related to psoas muscle inflammation and/or stretch injury to the genitofemoral nerve due to the surgical corridor traversed during the operation. No major injuries to the lumbar plexus were encountered. It is important to educate patients prior to surgery of the possibility of these largely transient symptoms.

Surgical management of cervical ossification of the posterior longitudinal ligament: natural history and the role of surgical decompression and stabilization.

OBJECT: Ossification of the posterior longitudinal ligament (OPLL) is a complex multifactorial disease process combining both metabolic and biomechanical factors. The role for surgical intervention and choice of anterior or posterior approach is controversial. The object of this study was to review the literature and present a single-institution experience with surgical intervention for OPLL. METHODS: The authors performed a retrospective review of their institutional experience with surgical intervention for cervical OPLL. They also reviewed the English-language literature regarding the epidemiology, pathophysiology, natural history, and surgical intervention for OPLL. RESULTS: Review of the literature suggests an improved benefit for anterior decompression and stabilization or posterior decompression and stabilization compared with posterior decompression via laminectomy or laminoplasty. Both anterior and posterior approaches are safe and effective means of decompression of cervical stenosis in the setting of OPLL. CONCLUSIONS: Anterior cervical decompression and reconstruction is a safe and appropriate treatment for cervical spondylitic myelopathy in the setting of OPLL. For patients with maintained cervical lordosis, posterior cervical decompression and stabilization is advocated. The use of laminectomy or laminoplasty is indicated in patients with preserved cervical lordosis and less than 60% of the spinal canal occupied by calcified ligament in a "hill-shaped" contour.

Minimally Invasive Intradural Tumor Resection.

In conjunction with neurofibromas, schwannomas are the second most commonly occurring intradural extramedullary tumor. They are a benign encapsulated nerve sheath tumor that are typically slow growing. They occur equally as frequently in the cervical and lumbar spine. If symptomatic, surgical resection may be warranted. In this surgical technique video, we present a case of a 70-year-old woman who presented with worsening symptoms consistent with cauda equina syndrome secondary to intradural masses at the L1-2 level. A minimally invasive resection of the intradural lesions was performed without any complication. Final pathology of the resected masses revealed schwannoma.

Incidence and Risk Factors for Postoperative Venous Thromboembolic Events in Patients Undergoing Cervical Spine Surgery.

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.