Prophylactic Muscle Flaps Decrease Wound Complication Rates in Patients with Oncologic Spine Disease.

BACKGROUND: Patients with oncologic spine disease face a high systemic illness burden and often require surgical intervention to alleviate pain and maintain spine stability. Wound healing complications are the most common reason for reoperation in this population and are known to impact quality of life and initiation of adjuvant therapy. Prophylactic muscle flap (MF) closure is known to reduce wound healing complications in high-risk patients; however, the efficacy in oncologic spine patients is not well established. METHODS: A collaboration at our institution presented an opportunity to study the outcomes of prophylactic MF closure. The authors performed a retrospective cohort study of patients who underwent MF closure versus a cohort who underwent non-MF closure in the preceding time. Demographic and baseline health data were collected, as were postoperative wound complication data. RESULTS: A total of 166 patients were enrolled, including 83 patients in the MF cohort and 83 control patients. Patients in the MF group were more likely to smoke ( P = 0.005) and had a higher incidence of prior spine irradiation ( P = 0.002). Postoperatively, five patients (6%) in the MF group developed wound complications, compared with 14 patients (17%) in the control group ( P = 0.028). The most common overall complication was wound dehiscence requiring conservative therapy, which occurred in six control patients (7%) and one MF patient (1%) ( P = 0.053). CONCLUSIONS: Prophylactic MF closure during oncologic spine surgery significantly reduces the wound complication rate. Future studies should examine the precise patient population that stands to benefit most from this intervention. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Robotic-Assisted Minimally Invasive Spinopelvic Fixation for Traumatic Sacral Fractures: Case Series Investigating Early Safety and Efficacy.

BACKGROUND: High-energy traumatic sacral fractures, particularly U-type or AOSpine classification type C fractures, may lead to significant functional deficits. Traditionally, spinopelvic fixation for unstable sacral fractures was performed with open reduction and fixation, but robotic-assisted minimally invasive surgical methods now present new, less invasive approaches. The objective here was to present a series of patients with traumatic sacral fractures treated with robotic-assisted minimally invasive spinopelvic fixation and discuss early experience, considerations, and technical challenges. METHODS: Between June 2022 and January 2023, 7 consecutive patients met the inclusion criteria. Intraoperative fluoroscopic images were merged with intraoperative computed tomography images using a robotic system to plan the trajectories for placement of bilateral lumbar pedicle and iliac screws. Intraoperative computed tomography was performed after pedicle and pelvic screw insertion to confirm appropriate placement before insertion of rods percutaneously without the need for a side connector. RESULTS: The cohort consisted of 7 patients (4 female, 3 male) with ages ranging from 20 to 74. Intraoperatively, the mean blood loss was 85.7 ± 84.0 mL, and mean operative time was 178.4 ± 63.9 minutes. There were no complications in 6 patients; 1 patient experienced both a medially breached pelvic screw and a complicated rod pullout. All patients were safely discharged to their homes or an acute rehabilitation facility. CONCLUSIONS: Our early experience reveals that robotic-assisted minimally invasive spinopelvic fixation for traumatic sacral fractures is a safe and feasible treatment option with the potential to improve outcomes and reduce complications.

A Comparison of Percutaneous Pedicle Screw Accuracy Between Robotic Navigation and Novel Fluoroscopy-Based Instrument Tracking for Patients Undergoing Instrumented Thoracolumbar Surgery.

BACKGROUND: The accuracy of pedicle screws placed with instrument tracking and robotic navigation are individually comparable or superior to placement using standard fluoroscopy, however head-to-head comparisons between these adjuncts in a similar surgical population have yet to be performed. METHODS: Consecutive patients undergoing percutaneous thoracic and lumbosacral spinal instrumentation were retrospectively enrolled. Instrumentation was performed using either fluoroscopy-based instrument tracking system (TrackX, TrackX Technologies) or robotic-navigation (ExcelsiusGPS, Globus Medical). Postinstrumentation computed tomography scans were graded for breach according to the Gertzbein-Robbins scale, with "acceptable" screws deemed as Grade A or B and "unacceptable" screws deemed as Grades C through E. Accuracy data was compared between both instrumentation modalities. RESULTS: Fifty-three patients, comprising a total of 250 screws (167 robot, 83 instrument tracking) were included. The overall accuracy between both modalities was similar, with 96.4% and 97.6% of screws with acceptable accuracy between instrument tracking and robotic navigation, respectively (I-squared 0.30, df = 1, P = 0.58). Between instrument tracking and robotic navigation, 92.8% and 95.8% of screws received Grade A, 3.6% and 1.8% a Grade B, 1.2% and 1.2% a Grade C, 1.2% and 0.6% a Grade D, and 1.2% and 0.6% a Grade E, respectively. The robot was abandoned intraoperatively in 2 cases due to unrecoverable registration inaccuracy or software failure, leading to abandonment of 8 potential screws (4.8%). CONCLUSIONS: In a similar patient population, there is a similarly high degree of instrumentation accuracy between fluoroscopy-based instrument tracking and robotic navigation. There is a rare chance for screw breach with either surgical adjunct.

Perioperative Pain Management for Elective Spine Surgery: Opioid Use and Multimodal Strategies.

In recent years, physicians and institutions have come to recognize the increasing opioid epidemic in the United States, thus prompting a dramatic shift in opioid prescribing patterns. The lack of well-studied alternative treatment regimens has led to a substantial burden of opioid addiction in the United States. These forces have led to a huge economic burden on the country. The spine surgery population is particularly high risk for uncontrolled perioperative pain, because most patients experience chronic pain preoperatively and many patients continue to experience pain postoperatively. Overall, there is a large incentive to better understand comprehensive multimodal pain management regimens, particularly in the spine surgery patient population. The goal of this review is to explore trends in pain symptoms in spine surgery patients, overview the best practices in pain medications and management, and provide a concise multimodal and behavioral treatment algorithm for pain management, which has since been adopted by a high-volume tertiary academic medical center.

Muscle Flap Closures in Spine Surgery: Predictors of Usage Patterns and Factors Associated With Postoperative Complications From the NSQIP Database.

STUDY DESIGN: Retrospective cohort study using the National Surgical Quality Improvement Program. OBJECTIVE: The objective of this study was to identify preoperative factors that impact the decision to perform prophylactic muscle flap closure and assess risk factors for wound healing complications in patients undergoing spinal procedures with and without muscle flap closure. SUMMARY OF BACKGROUND DATA: Prior studies suggest that muscle flap closure following complex spine surgery results in a lower risk of wound healing complications. However, these studies have been limited to single institutions and/or surgeons. METHODS: The National Surgical Quality Improvement Program database was queried for all patients undergoing spine surgery between 2005 and 2017 with and without concomitant muscle flaps. Preoperative and perioperative variables were extracted. Univariate and multivariate analyses were performed to assess risk factors influencing surgical site infection (SSI) and wound disruption, as well as to delineate which preoperative factors increased the likelihood of patients receiving flap closures a priori. RESULTS: Concomitant muscle flaps were performed on 758 patients; 301,670 patients did not receive a flap. Overall 29 (3.83%) patients in the flap group experienced SSI compared to 5154 (1.71%) in the nonflap group (P<0.0001). Preoperative steroid use [odds ratio (OR) 0.5; P<0.0001], wound infection (OR 0.24; P<0.0001), elevated white blood cell count (OR 1.034; P<0.0001), low hematocrit (OR 0.94; P<0.0001), preoperative transfusion (OR 0.22; P=0.0068) were significantly associated with utilization of muscle flaps. Perioperative factors including a contaminated wound (OR 4.72; P<0.0001), the American Society of Anesthesiologists classification of severe disease (OR 1.92; P=0.024), and longer operative time (OR 1.001; P=0.0024) were significantly associated with postoperative wound disruption. In addition, after propensity score matching for these factors that increase risk of wound complications, there was no difference in the rates of SSI between the flap and nonflap group. CONCLUSION: Our results suggest that patients with a higher burden of illness preoperatively are more likely to receive prophylactic paraspinal flaps which can reduce the rates of wound-related complications.

Management of Acute Traumatic Spinal Cord Injury: A Review of the Literature.

Traumatic spinal cord injury (TSCI) is a debilitating disease that poses significant functional and economic burden on both the individual and societal levels. Prognosis is dependent on the extent of the spinal injury and the severity of neurological dysfunction. If not treated rapidly, patients with TSCI can suffer further secondary damage and experience escalating disability and complications. It is important to quickly assess the patient to identify the location and severity of injury to make a decision to pursue a surgical and/or conservative management. However, there are many conditions that factor into the management of TSCI patients, ranging from the initial presentation of the patient to long-term care for optimal recovery. Here, we provide a comprehensive review of the etiologies of spinal cord injury and the complications that may arise, and present an algorithm to aid in the management of TSCI.

Robotic-Assisted Trajectory Into Kambin's Triangle During Percutaneous Transforaminal Lumbar Interbody Fusion-Initial Case Series Investigating Safety and Efficacy.

BACKGROUND: Minimally invasive spine surgery (MISS) has the potential to further advance with the use of robot-assisted (RA) techniques. While RA pedicle screw placement has been extensively investigated, there is a lack of literature on the use of the robot for other tasks, such as accessing Kambin's triangle in percutaneous lumbar interbody fusion (percLIF). OBJECTIVE: To characterize the surgical feasibility and preliminary outcomes of an initial case series of 10 patients receiving percLIF with RA cage placement via Kambin's triangle. METHODS: We performed a single-center, retrospective review of patients undergoing RA percLIF using robot-guided trajectory to access Kambin's triangle for cage placement. Patients undergoing RA percLIF were eligible for enrollment. Baseline health and demographic information in addition to peri- and postoperative data was collected. The dimensions of each patient's Kambin's triangle were measured. RESULTS: Ten patients and 11 levels with spondylolisthesis were retrospectively reviewed. All patients successfully underwent the planned procedure without perioperative complications. Four patients underwent their procedure with awake anesthesia. The average dimension of Kambin's triangle was 66.3 m2. With the exception of 1 patient who stayed in the hospital for 7 d, the average length of stay was 1.2 d, with 2 patients discharged the day of surgery. No patients suffered postoperative motor or sensory deficits. Spinopelvic parameters and anterior and posterior disc heights were improved with surgery. CONCLUSION: As MISS continues to evolve, further exploration of robot-guided surgical practice, such as our technique, will lead to creative solutions to challenging anatomical variation and overall improved patient care.

Risk factors for prolonged length of stay in patients undergoing surgery for intramedullary spinal cord tumors.

Primary spine tumors are rare neoplasms that affect about 0.62 per 100,000 individuals in the US. Intramedullary spinal cord tumors (IMSCTs) are the rarest of all primary tumors involving the spine and can cause pain, imbalance, urinary dysfunction and neurological deficits. These types of tumors oftentimes necessitate surgical treatment, yet there is a lack of data on hospital length of stay and complication rates following treatment. Given that treatment candidacy, quality of life, and outcomes are tied so closely to potential for prolonged length of stay and postoperative complications, it is important to better understand the factors that increase the risk of these outcomes in patients with IMSCTs. METHODS: The National Surgical Quality Improvement Program (NSQIP) database was queried for all patients undergoing surgery for treatment of intramedullary spinal cord tumors between 2005 and 2017. Univariate and multivariate analysis were performed to assess patient risk factors influencing prolonged length of stay and post-op complications. RESULTS: A total of 638 patients were included in the analysis. Pre-operative American Society of Anesthesiology (ASA) physical status classification of 3 and above (OR 1.89; p = 0.0005), dependent functional status (OR 2.76; p = 0.0035) and transfer from facilities other than home (OR 8.12; p <0.0001) were independent predictors of prolonged length of stay (>5 days). The most commonly reported complications were pneumonia (5.7%), urinary tract infection (9.4%), septic shock (3.8%), superficial incisional infection (5.7%), organ or space infection (5.7%), pulmonary embolism (11.3%), DVT requiring therapy (15.1%) and wound dehiscence (5.7%). CONCLUSION: Our study demonstrated the significant influence of clinical variables on prolonged hospitalization of IMSCT patients. This should be factored into clinical and surgical decision making and when counseling patients of their expected outcomes.

Robotic-assisted percutaneous iliac screw fixation for destructive lumbosacral metastatic lesions: an early single-institution experience.

BACKGROUND: Robotic-assisted surgery is becoming more widely applied in surgical subspecialties due to its intraoperative and postoperative advantages such as minimally invasive approach, reduced blood loss, shorter hospital stay, and decreased incidence of postoperative complications. However, robotic devices were only recently introduced in the field of spinal surgery. Specifically, percutaneous approaches involving computer-assisted image guidance are relatively new in iliac screw fixation. Previous methods focused on the use of S2-alar-iliac (S2AI) screw fixation which allows for pelvic fixation without a need for side connectors. However, for patients with destructive lesions of the sacrum, placement of these S2AI screws may not be feasible. The purpose of this technical note is to illustrate the implementation of robotic-assisted percutaneous iliac screw fixation in two cases which allows for minimally invasive attachment to the proximal lumbar screws without a side connector and eliminates a potential source of instrumentation failure. METHODS: Robotic-assisted percutaneous iliac screw fixation was performed on two patients. The robotics system was used to merge the fluoroscopic images with intraoperative computed tomography (CT) images to plan the trajectories for placement of bilateral pedicle and iliac screws. Intraoperative CT scan was again performed to confirm proper placement of all screws. Rods were then engaged bilaterally with the pedicle and iliac screws without the use of side connectors. RESULTS: The patients did not experience immediate postoperative complications and had stable hardware at one-month follow-up. Our cases demonstrate the surgical efficiency of robotic-assisted lumbo-iliac instrumentation which obviates the need to use a side connector, which is commonly used in iliac fixation. This eliminates a step, which can reduce the possibility of instrumentation failure. CONCLUSION: Robotic-assisted percutaneous iliac screw fixation is a safe and feasible technique to improve operative and clinical outcomes in complex spinal instrumentation surgeries.

Front-Back Cervical Deformity Correction by Anterior Cervical Discectomy and Fusion With Posterior Instrumentation: 2-Dimensional Operative Video.

Front-back procedures for cervical deformity permit the correction of cervical kyphosis in the setting of unfused facets. Here, we highlight the operative treatment of a 65-yr-old female entailing a 4-level anterior cervical discectomy and fusion (ACDF) at C3-C4, C4-C5, C5-C6, and C6-C7 with hyperlordotic interbody implants, supplemented by a posterior C2-T2 instrumented fusion. The patient initially presented with symptoms of treatment-refractory neck pain while neurologically intact on examination. Her imaging demonstrated significant cervical kyphosis measuring 46° as the Cobb angle between C2 and C7 without neural compression. The patient consented to the procedure and publication of their image. After 2 d of traction, the operation proceeded with the patient initially in a supine position with dissection medial to the sternocleidomastoid muscle down to the vertebral bodies. Discectomies were performed at each level followed by installation of the interbody implants. After closure of this access wound, the patient was turned to a prone position for the posterior element of the operation. The posterior bony elements were exposed and a C2-T2 instrumented fusion performed. Postoperative imaging demonstrated improvement of her sagittal cervical curvature and the patient described improvement in her neck pain.

Pseudarthrosis rate following anterior cervical discectomy with fusion using an allograft cellular bone matrix: a multi-institutional analysis.

OBJECTIVE: The use of osteobiologics, engineered materials designed to promote bone healing by enhancing bone growth, is becoming increasingly common for spinal fusion procedures, but the efficacy of some of these products is unclear. The authors performed a retrospective, multi-institutional study to investigate the clinical and radiographic characteristics of patients undergoing single-level anterior cervical discectomy with fusion performed using the osteobiologic agent Osteocel, an allograft mesenchymal stem cell matrix. METHODS: The medical records across 3 medical centers and 12 spine surgeons were retrospectively queried for patients undergoing single-level anterior cervical discectomy and fusion (ACDF) with the use of Osteocel. Pseudarthrosis was determined based on CT or radiographic imaging of the cervical spine. Patients were determined to have radiographic pseudarthrosis if they met any of the following criteria: 1) lack of bridging bone on CT obtained > 300 days postoperatively, 2) evidence of instrumentation failure, or 3) motion across the index level as seen on flexion-extension cervical spine radiographs. Univariate and multivariate analyses were then performed to identify independent preoperative or perioperative predictors of pseudarthrosis in this population. RESULTS: A total of 326 patients met the inclusion criteria; 43 (13.2%) patients met criteria for pseudarthrosis, of whom 15 (34.9%) underwent revision surgery. There were no significant differences between patients with and those without pseudarthrosis, respectively, for patient age (54.1 vs 53.8 years), sex (34.9% vs 47.4% male), race, prior cervical spine surgery (37.2% vs 33.6%), tobacco abuse (16.3% vs 14.5%), chronic kidney disease (2.3% vs 2.8%), and diabetes (18.6% vs 14.5%) (p > 0.05). Presence of osteopenia or osteoporosis (16.3% vs 3.5%) was associated with pseudarthrosis (p < 0.001). Implant type was also significantly associated with pseudarthrosis, with a 16.4% rate of pseudarthrosis for patients with polyetherethereketone (PEEK) implants versus 8.4% for patients with allograft implants (p = 0.04). Average lengths of follow-up were 27.6 and 23.8 months for patients with and those without pseudarthrosis, respectively. Multivariate analysis demonstrated osteopenia or osteoporosis (OR 4.97, 95% CI 1.51-16.4, p < 0.01) and usage of PEEK implant (OR 2.24, 95% CI 1.04-4.83, p = 0.04) as independent predictors of pseudarthrosis. CONCLUSIONS: In patients who underwent single-level ACDF, rates of pseudarthrosis associated with the use of the osteobiologic agent Osteocel are higher than the literature-reported rates associated with the use of alternative osteobiologics. This is especially true when Osteocel is combined with a PEEK implant.

Impact of US hospital center and interhospital transfer on spinal cord injury management: An analysis of the National Trauma Data Bank.

BACKGROUND: Traumatic spinal cord injury (SCI) is a serious public health problem. Outcomes are determined by severity of immediate injury, mitigation of secondary downstream effects, and rehabilitation. This study aimed to understand how the center type a patient presents to and whether they are transferred influence management and outcome. METHODS: The National Trauma Data Bank was used to identify patients with SCI. The primary objective was to determine association between center type, transfer, and surgical intervention. A secondary objective was to determine association between center type, transfer, and surgical timing. Multivariable logistic regression models were fit on surgical intervention and timing of the surgery as binary variables, adjusting for relevant clinical and demographic variables. RESULTS: There were 11,744 incidents of SCI identified. A total of 2,883 patients were transferred to a Level I center and 4,766 presented directly to a level I center. Level I center refers to level I trauma center. Those who were admitted directly to level I centers had a higher odd of receiving a surgery (odds ratio, 1.703; 95% confidence interval, 1.47-1.97; p < 0.001), but there was no significant difference in terms of timing of surgery. Patients transferred into a level I center were also more likely to undergo surgery than those at a level II/III/IV center, although this was not significant (odds ratio, 1.213; 95% confidence interval, 0.099-1.48; p = 0.059). CONCLUSION: Patients with traumatic SCI admitted to level I trauma centers were more likely to have surgery, particularly if they were directly admitted to a level I center. This study provides insights into a large US sample and sheds light on opportunities for improving pre hospital care pathways for patients with traumatic SCI, to provide the timely and appropriate care and achieve the best possible outcomes. LEVEL OF EVIDENCE: Care management, Level IV.

Characterization and rate of symptomatic adjacent-segment disease after index lateral lumbar interbody fusion: a single-institution, multisurgeon case series with long-term follow-up.

OBJECTIVE: The rate of symptomatic adjacent-segment disease (ASD) after newer minimally invasive techniques, such as lateral lumbar interbody fusion (LLIF), is not known. This study aimed to assess the incidence of surgically significant ASD in adult patients who have undergone index LLIF and to identify any predictive factors. METHODS: Patients who underwent index LLIF with or without additional posterior pedicle screw fixation between 2010 and 2012 and received a minimum of 2 years of postoperative follow-up were retrospectively included. Demographic and perioperative data were recorded, as well as radiographic data and immediate perioperative complications. The primary endpoint was revision surgery at the level above or below the previous construct, from which a survivorship model of patients with surgically significant symptomatic ASD was created. RESULTS: Sixty-seven patients with a total of 163 interbody levels were included in this analysis. In total, 17 (25.4%) patients developed surgically significant ASD and required additional surgery, with a mean ± SD time to revision of 3.59 ± 2.55 years. The mean annual rate of surgically significant ASD was 3.49% over 7.27 years, which was the average follow-up. One-third of patients developed significant disease within 2 years of index surgery, and 1 patient required surgery at the adjacent level within 1 year. Constructs spanning 3 or fewer interbody levels were significantly associated with increased risk of surgically significant ASD; however, instrument termination at the thoracolumbar junction did not increase this risk. Surgically significant ASD was not impacted by preoperative disc height, foraminal area at the adjacent levels, or changes in global or segmental lumbar lordosis. CONCLUSIONS: The risk of surgically significant ASD after LLIF was similar to the previously reported rates of other minimally invasive spine procedures. Patients with shorter constructs had higher rates of subsequent ASD.

Interhospital transfer status for spinal metastasis patients in the United States is associated with more severe clinical presentations and higher rates of inpatient complications.

OBJECTIVE: In patients with metastatic spinal disease (MSD), interhospital transfer can potentially impact clinical outcomes as the possible benefits of transferring a patient to a higher level of care must be weighed against the negative effects associated with potential delays in treatment. While the association of clinical outcomes and transfer status has been examined in other specialties, the relationship between transfer status, complications, and risk of mortality in patients with MSD has yet to be explored. The purpose of this study was to examine the impact of transfer status on in-hospital mortality and clinical outcomes in patients diagnosed with MSD. METHODS: The National (Nationwide) Inpatient Sample (NIS) database was retrospectively queried for adult patients diagnosed with vertebral pathological fracture and/or spinal cord compression in the setting of metastatic disease between 2012 and 2014. Demographics, baseline characteristics (e.g., metastatic spinal cord compression [MSCC] and paralysis), comorbidities, type of intervention, and relevant patient outcomes were controlled in a multivariable logistic regression model to analyze the association of transfer status with patient outcomes. RESULTS: Within the 10,360 patients meeting the inclusion and exclusion criteria, higher rates of MSCC (50.2% vs 35.9%, p < 0.001) and paralysis (17.3% vs 8.4%, p < 0.001) were observed in patients transferred between hospitals compared to those directly admitted. In univariable analysis, a higher percentage of transferred patients underwent surgical intervention (p < 0.001) when compared with directly admitted patients. After controlling for significant covariates and surgical intervention, transferred patients were more likely to develop in-hospital complications (OR 1.34, 95% CI 1.18-1.52, p < 0.001), experience prolonged length of stay (OR 1.33, 95% CI 1.16-1.52, p < 0.001), and have a discharge disposition other than home (OR 1.70, 95% CI 1.46-1.98, p < 0.001), with no significant difference in inpatient mortality rates. CONCLUSIONS: Patients with MSD who were transferred between hospitals demonstrated more severe clinical presentations and higher rates of inpatient complications compared to directly admitted patients, despite demonstrating no difference in in-hospital mortality rates.

Percutaneous Lumbar Interbody Fusion With an Expandable Titanium Cage Through Kambin's Triangle: A Case Series With Initial Clinical and Radiographic Results.

BACKGROUND: There has been an increased interest in lumbar interbody fusions through Kambin's triangle. In this study, we describe percutaneous access to the lumbar disc and insertion of an expandable titanium cage through Kambin's triangle without facetectomy. The objective of this study is to determine the feasibility as well as clinical and radiographical outcomes of completely percutaneous lumbar interbody fusion (percLIF) using an expandable titanium cage through Kambin's triangle. METHODS: A retrospective review of patients undergoing single-level percLIF for grade 1 lumbar spondylolisthesis via Kambin's triangle using an expandable titanium cage was performed. Demographic information, Oswestry Disability Index (ODI), preoperative and postoperative radiographic factors, perioperative data, and complications were recorded. Fusion was assessed with 1-year postoperative computed tomography scan or lumbar spine x-ray and defined as bridging disc or posterolateral fusion without evidence of hardware fracture or perihardware lucency. RESULTS: A total of 16 patients (3 males) were included in this study. Spondylolisthesis, anterior disc height, and posterior disc height were significantly improved at 6 weeks, 6 months, and 12 months, postoperatively (P < 0.05). ODI was significantly improved by 24.4% at 12 months postoperatively (P = 0.0036). One patient was readmitted within 30 days for pain control but otherwise there were no complications including permanent neurological injury, infection, deep vein thrombosis, pulmonary embolism, or cardiac events. Fifteen (93.8%) patients had radiographic fusion at their 1-year postoperative imaging. CONCLUSION: Our initial experiences have shown that percLIF can be performed using an expandable titanium cage through Kambin's triangle with excellent radiographic and clinical results. In this series, percLIF is a safe and clinically efficacious procedure for reducing grade 1 lumbar spondylolisthesis and improving radiculopathy. This procedure is completed percutaneously without the use of an endoscope. CLINICAL RELEVANCE: This study highlights improvements in outcomes of minimally invasive surgery. LEVEL OF EVIDENCE: IV.

Biomechanics, evaluation, and management of subaxial cervical spine injuries: A comprehensive review of the literature.

STUDY DESIGN: Literature review. OBJECTIVES: It has been reported that 2.4-3.7% of all blunt trauma victims suffer some element of cervical spine fracture, with the majority of these patients suffering from C3-7 (subaxial) involvement. With the improvement of first-response to trauma in the community, there are an increasing number of patients who survive their initial trauma and thus arrive at the hospital in need of further evaluation, stabilization, and management of these injuries. METHODS: A comprehensive literature review compiled all relevant data on the biomechanics, imaging, evaluation, and medical and surgical management strategies for subaxial cervical spine fractures. RESULTS: After review of the current literature on subaxial cervical spine biomechanics, imaging characteristics, evaluation strategies and surgical and orthopedic management techniques, the authors created a comprehensive review and protocol for management of subaxial cervical spine fractures. CONCLUSIONS: The subaxial cervical spine is biomechanically and anatomically unique from the remainder of the spinal axis. Evaluation of subaxial cervical spine injuries is nuanced, and improper management of these injuries can lead to significant patient morbidity and even death. This provides a comprehensive review combining anatomy, imaging characteristics, evaluation strategies, and surgical and orthopedic management principles for subaxial cervical spine fractures.

"The eye sees only what the mind is prepared to comprehend": Unrecognized incidental findings on intraoperative computed tomography during spine instrumentation surgery.

BACKGROUND: Intraoperative computed tomography (CT) is becoming more widely utilized in spine fusion surgeries. The use of CT-based image guidance has been shown to increase the accuracy in instrumentation placement and to reduce the rate of reoperation. However, incidental findings that are obvious in retrospect are still missed in spinal fusion surgeries due to the concept of inattentional blindness and surgeons' preoccupation with the main objective of intraoperative CT (i.e. instrumentation accuracy). CASE DESCRIPTION: The first case describes a 60-year-old male who underwent posterior spinal laminectomy and interbody fusions from L2-L5. Intraoperative CT confirmed appropriate placement of hardware. However, when he was transferred out to the care unit and extubated, he developed a severe headache for which the source was confirmed to be a pneumocephalus from durotomy and cerebrospinal fluid leakage on repeat CT. A retrospective review of his intraoperative CT demonstrated the intrathecal air at L5-S1 interlaminar space that was missed on evaluation during surgery. The second case describes a 68-year-old female who was treated with a successful T4 to pelvis instrumentation and fusion with vertebral column resection at T10 confirmed with imaging. Postoperatively, she developed rapidly progressive oxygen desaturation and was found to have a pneumothorax which had been present on the intraoperative imaging. CONCLUSION: This case report of two patients with missed intraoperative findings demonstrates the importance of looking beyond instrumentation placement and evaluating the entire intraoperative CT imaging to find abnormalities that could complicate the patients' postoperative recovery and overall hospital stay.

Hematocrit as a predictor of preoperative transfusion-associated complications in spine surgery: A NSQIP study.

BACKGROUND CONTEXT: Preoperative optimization of medical comorbidities prior to spinal surgery is becoming an increasingly important intervention in decreasing postoperative complications and ensuring a satisfactory postoperative course. The treatment of preoperative anemia is based on guidelines made by the American College of Cardiology (ACC), which recommends packed red blood cell transfusion when hematocrit is less than 21% in patients without cardiovascular disease and 24% in patients with cardiovascular disease. The literature has yet to quantify the risk profile associated with preoperative pRBC transfusion. PURPOSE: To determine the incidence of complications following preoperative pRBC transfusion in a cohort of patients undergoing spine surgery. STUDY DESIGN: Retrospective review of a national surgical database. PATIENT SAMPLE: The national surgical quality improvement program database OUTCOME NEASURES: Postoperative physiologic complications after a preoperative transfusion. Complications were defined as the occurrence of any DVT, PE, stroke, cardiac arrest, myocardial infarction, longer length of stay, need for mechanical ventilation greater than 48 h, surgical site infections, sepsis, urinary tract infections, pneumonia, or higher 30-day mortality. METHODS: The national surgical quality improvement program database was queried, and patients were included if they had any type of spine surgery and had a preoperative transfusion. RESULTS: Preoperative pRBC transfusion was found to be protective against complications when the hematocrit was less than 20% and associated with more complications when the hematocrit was higher than 20%. In patients with a hematocrit higher than 20%, pRBC transfusion was associated with longer lengths of stay, and higher rates of ventilator dependency greater than 48 h, pneumonia, and 30-day mortality. CONCLUSION: This is the first study to identify an inflection point in determining when a preoperative pRBC transfusion may be protective or may contribute to complications. Further studies are needed to be conducted to stratify by the prevalence of cardiovascular disease.

Patient outcomes and tumor control in single-fraction versus hypofractionated stereotactic body radiation therapy for spinal metastases.

OBJECTIVE: Stereotactic body radiation therapy (SBRT) offers efficient, noninvasive treatment of spinal neoplasms. Single-fraction (SF) high-dose SBRT has a relatively narrow therapeutic window, while hypofractionated delivery of SBRT may have an improved safety profile with similar efficacy. Because the optimal approach of delivery is unknown, the authors examined whether hypofractionated SBRT improves pain and/or functional outcomes and results in better tumor control compared with SF-SBRT. METHODS: This is a single-institution retrospective study of adult patients with spinal metastases treated with SF- or three-fraction (3F) SBRT from 2008 to 2019. Demographics and baseline characteristics, radiographic data, and posttreatment outcomes at a minimum follow-up of 3 months are reported. RESULTS: Of the 156 patients included in the study, 70 (44.9%) underwent SF-SBRT (median total dose 1700 cGy) and 86 (55.1%) underwent 3F-SBRT (median total dose 2100 cGy). At baseline, a higher proportion of patients in the 3F-SBRT group had a worse baseline profile, including severity of pain (p < 0.05), average use of pain medication (p < 0.001), and functional scores (p < 0.05) compared with the SF-SBRT cohort. At the 3-month follow-up, the 3F-SBRT cohort experienced a greater frequency of improvement in pain compared with the SF-SBRT group (p < 0.05). Furthermore, patients treated with 3F-SBRT demonstrated a higher frequency of improved Karnofsky Performance Scale (KPS) scores (p < 0.05) compared with those treated with SF-SBRT, with no significant difference in the frequency of improvement in modified Rankin Scale scores. Local tumor control did not differ significantly between the two cohorts. CONCLUSIONS: Patients who received spinal 3F-SBRT more frequently achieved significant pain relief and an increased frequency of improvement in KPS compared with those treated with SF-SBRT. Local tumor control was similar in the two groups. Future work is needed to establish the relationship between fractionation schedule and clinical outcomes.