Advances and Challenges in Minimally Invasive Spine Surgery.

Minimally invasive spine surgery continues to grow and develop. Over the past 50 years, there has been immense growth within this subspecialty of neurosurgery. A deep understanding of the historical context and future directions of this subspecialty is imperative to developing safe adoption and targeted innovation. This review aims to describe the advancements, and challenges that we face today in minimally invasive spine surgery.

Early Experience with Prone Lateral Interbody Fusion in Deformity Correction: A Single-Institution Experience.

Background/Objectives: Lateral spine surgery offers effective minimally invasive deformity correction, but traditional approaches often involve separate anterior, lateral, and posterior procedures. The prone lateral technique streamlines this process by allowing single-position access for lateral and posterior surgery, potentially benefiting from the lordosing effect of prone positioning. While previous studies have compared prone lateral to direct lateral for adult degenerative diseases, this retrospective review focuses on the outcomes of adult deformity patients undergoing prone lateral interbody fusion. Methods: Ten adult patients underwent single-position prone lateral surgery for spine deformity correction, with a mean follow-up of 18 months. Results: Results showed significant improvements: sagittal vertical axis decreased by 2.4 cm, lumbar lordosis increased by 9.1°, pelvic tilt improved by 3.3°, segmental lordosis across the fusion construct increased by 12.2°, and coronal Cobb angle improved by 6.3°. These benefits remained consistent over the follow-up period. Correlational analysis showed a positive association between improvements in PROs and SVA and SL. When compared to hybrid approaches, prone lateral yielded greater improvements in SVA. Conclusions: Prone lateral surgery demonstrated favorable outcomes with reasonable perioperative risks. However, further research comparing this technique with standard minimally invasive lateral approaches, hybrid, and open approaches is warranted for a comprehensive evaluation.

Pushing the Limits of Minimally Invasive Spine Surgery-From Preoperative to Intraoperative to Postoperative Management.

The introduction of minimally invasive surgery ushered in a new era of spine surgery by minimizing the undue iatrogenic injury, recovery time, and blood loss, among other complications, of traditional open procedures. Over time, technological advancements have further refined the care of the operative minimally invasive spine patient. Moreover, pre-, and postoperative care have also undergone significant change by way of artificial intelligence risk stratification, advanced imaging for surgical planning and patient selection, postoperative recovery pathways, and digital health solutions. Despite these advancements, challenges persist necessitating ongoing research and collaboration to further optimize patient care in minimally invasive spine surgery.

Advancing Prone-Transpsoas Spine Surgery: A Narrative Review and Evolution of Indications with Representative Cases.

The Prone Transpsoas (PTP) approach to lumbar spine surgery, emerging as an evolution of lateral lumbar interbody fusion (LLIF), offers significant advantages over traditional methods. PTP has demonstrated increased lumbar lordosis gains compared to LLIF, owing to the natural increase in lordosis afforded by prone positioning. Additionally, the prone position offers anatomical advantages, with shifts in the psoas muscle and lumbar plexus, reducing the likelihood of postoperative femoral plexopathy and moving critical peritoneal contents away from the approach. Furthermore, operative efficiency is a notable benefit of PTP. By eliminating the need for intraoperative position changes, PTP reduces surgical time, which in turn decreases the risk of complications and operative costs. Finally, its versatility extends to various lumbar pathologies, including degeneration, adjacent segment disease, and deformities. The growing body of evidence indicates that PTP is at least as safe as traditional approaches, with a potentially better complication profile. In this narrative review, we review the historical evolution of lateral interbody fusion, culminating in the prone transpsoas approach. We also describe several adjuncts of PTP, including robotics and radiation-reduction methods. Finally, we illustrate the versatility of PTP and its uses, ranging from 'simple' degenerative cases to complex deformity surgeries.

Using Novel Segmentation Technology to Define Safe Corridors for Minimally Invasive Posterior Lumbar Interbody Fusion.

BACKGROUND AND OBJECTIVES: There has been a rise in minimally invasive methods to access the intervertebral disk space posteriorly given their decreased tissue destruction, lower blood loss, and earlier return to work. Two such options include the percutaneous lumbar interbody fusion through the Kambin triangle and the endoscopic transfacet approach. However, without accurate preoperative visualization, these approaches carry risks of damaging surrounding structures, especially the nerve roots. Using novel segmentation technology, our goal was to analyze the anatomic borders and relative sizes of the safe triangle, trans-Kambin, and the transfacet corridors to assist surgeons in planning a safe approach and determining cannula diameters. METHODS: The areas of the safe triangle, Kambin, and transfacet corridors were measured using commercially available software (BrainLab, Munich, Germany). For each approach, the exiting nerve root, traversing nerve roots, theca, disk, and vertebrae were manually segmented on 3-dimensional T2-SPACE magnetic resonance imaging using a region-growing algorithm. The triangles' borders were delineated ensuring no overlap between the area and the nerves. RESULTS: A total of 11 patients (65.4 ± 12.5 years, 33.3% female) were retrospectively reviewed. The Kambin, safe, and transfacet corridors were measured bilaterally at the operative level. The mean area (124.1 ± 19.7 mm2 vs 83.0 ± 11.7 mm2 vs 49.5 ± 11.4 mm2) and maximum permissible cannula diameter (9.9 ± 0.7 mm vs 6.8 ± 0.5 mm vs 6.05 ± 0.7 mm) for the transfacet triangles were significantly larger than Kambin and the traditional safe triangles, respectively (P < .001). CONCLUSION: We identified, in 3-dimensional, the borders for the transfacet corridor: the traversing nerve root extending inferiorly until the caudal pedicle, the theca medially, and the exiting nerve root superiorly. These results illustrate the utility of preoperatively segmenting anatomic landmarks, specifically the nerve roots, to help guide decision-making when selecting the optimal operative approach.

Two-Year Clinical and Radiographic Outcomes for Percutaneous Lumbar Interbody Fusion With an Expandable Titanium Cage Through Kambin's Triangle Without Facetectomy.

BACKGROUND: There has been heightened interest in performing percutaneous lumbar interbody fusions (percLIFs) through Kambin's triangle, an anatomic corridor allowing entrance into the disc space. However, due to its novelty, there are limited data regarding the long-term benefits of this procedure. Our objective was to determine the long-term efficacy and durability of the percutaneous insertion of an expandable titanium cage through Kambin's triangle without facetectomy. METHODS: A retrospective review of patients undergoing percLIF via Kambin's triangle using an expandable titanium cage was performed. Demographics, visual analog scale (VAS) scores, Oswestry Disability Index (ODI), radiographic measurements, perioperative variables, and complications were recorded. VAS, ODI, and radiographic measurements were compared with baseline using the generalized estimating equations assuming normally distributed data. Fusion was assessed with computed tomography (CT) at 1 and 2 years after the procedure. RESULTS: A total of 49 patients were included. Spondylolisthesis, lumbar lordosis (LL), sacral slope, pelvic tilt, and anterior/posterior disc space height were all significantly improved postoperatively at each time point of 3, 6, 12, and 24 months (P < 0.001). Pelvic incidence-LL mismatch decreased significantly at each follow-up (P < 0.001) with a mean reduction of 4° by 24 months. VAS back scores reduced by >2 points at the 6, 12, and 24 month follow-ups. ODI scores reduced by >15 points at the 12- and 24-month follow-ups. Of the patients who had 1- and 2-year CT images, fusion rates at those time points were 94.4% (17/18) and 87.5% (7/8), respectively. The mean annual rate of surgically significant adjacent segment disease was 2.74% through an average follow-up of 2.74 years. CONCLUSION: These results highlight that percLIF, a procedure done without an endoscope or facetectomy, can be performed using an expandable titanium cage through Kambin's triangle with excellent radiographic and clinical results. CLINICAL RELEVANCE: percLIF via Kambin's triangle is a safe and succesful procedure with long-term improvements in both clinical and radiographic outcomes.

Enterothecal fistula as a rare cause of adult pneumocephalus and meningitis: a case report.

Background: Enterothecal fistulas are pathological connections between the gastrointestinal system and subarachnoid space. These rare fistulas occur mostly in pediatric patients with sacral developmental anomalies. They have yet to be characterized in an adult born without congenital developmental anomaly yet must remain on the differential diagnosis when all other causes of meningitis and pneumocephalus have been ruled out. Good outcomes rely on aggressive multidisciplinary medical and surgical care, which are reviewed in this manuscript. Case Description: A 25-year-old female with history of a sacral giant cell tumor resected via anterior transperitoneal approach followed by posterior L4-pelvis fusion presented with headaches and altered mental status. Imaging revealed that a portion of small bowel had migrated into her resection cavity and created an enterothecal fistula resulting in fecalith within the subarachnoid space and florid meningitis. The patient underwent a small bowel resection for fistula obliteration, and subsequently developed hydrocephalus requiring shunt placement and two suboccipital craniectomies for foramen magnum crowding. Ultimately, her wounds became infected requiring washouts and instrumentation removal. Despite a prolonged hospital course, she made significant recovery and at 10-month following presentation, she is awake, oriented, and able to participate in activities of daily living. Conclusions: This is the first case of meningitis secondary to enterothecal fistula in a patient without a previous congenital sacral anomaly. Operative intervention for fistula obliteration is the primary treatment and should be performed at a tertiary hospital with multidisciplinary capabilities. If recognized quickly and appropriately treated, there is a possibility of good neurological outcome.

Novel Approach to Percutaneous Lumbar Surgeries via Kambin's Triangle-Radiographic and Surgical Planning Analysis with Nerve Segmentation Technology.

OBJECTIVE: While Kambin's Triangle has become an ever more important anatomic window given its proximity to the exiting nerve root, there have been limited studies examining the effect of disease on the corridor. Our goal was to better understand how pathology can affect Kambin's Triangle, thereby altering the laterality of approach for percutaneous lumbar interbody fusion (percLIF). METHODS: The authors performed a single-center retrospective review of patients evaluated for percLIF. The areas of Kambin's Triangle were measured without and with nerve segmentation. For the latter, the lumbosacral nerve roots on 3-dimensional T2 magnetic resonance imaging were manually segmented. Next, the borders of Kambin's Triangle were delineated, ensuring no overlap between the area and nerve above. RESULTS: Fifteen patients (67.5 ± 9.7 years, 46.7% female) were retrospectively reviewed. We measured 150 Kambin's Triangles. The mean areas from L1-S1 were 50.0 ± 12.3 mm2, 73.8 ± 12.5 mm2, 83.8 ± 12.2 mm2, 88.5 ± 19.0 mm2, and 116 ± 29.3 mm2, respectively. When pathology was present, the areas significantly decreased at L4-L5 (P = 0.046) and L5-S1 (P = 0.049). Higher spondylolisthesis and smaller posterior disk heights were linked with decreased areas via linear regression analysis (P < 0.05). When nerve segmentation was used, the areas were significantly smaller from L1-L5 (P < 0.05). Among 11 patients who underwent surgery, none suffered from postoperative neuropathies. CONCLUSIONS: These results illustrate the feasibility of preoperatively segmenting lumbosacral nerves and measuring Kambin's Triangle to help guide surgical planning and determine the ideal laterality of approach for percLIF.

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.

Awake spinal anesthesia facilitates spine surgery in poor surgical candidates: A case series.

BACKGROUND: Annually, hundreds of thousands of patients undergo surgery for degenerative spine disease (DSD). This represents only a fraction of patients that present for surgical consideration. Procedures are often avoided due to comorbidities that make patients poor candidates for general anesthesia (GA) and its associated risks. With increasing interest in awake surgery under spinal anesthesia (SA), the authors have observed that SA may facilitate spine surgery in patients with relative contraindications to GA. With this in mind, the authors set out to summarize the outcomes of a series of highly comorbid patients who received surgery under SA. METHODS: Case logs of a single surgeon were reviewed, and patients undergoing spine surgery under SA were identified. Within this group, patients were identified with relative contraindications to GA, such as advanced age and medical comorbidities. For these patients, for whom surgery was facilitated by SA, the medical records were consulted to report demographic information and patient outcomes. RESULTS: Ten highly comorbid patients were identified who received lumbar spine surgery for DSD under SA. Comorbidities included octogenarian status, obesity, and chronic health conditions such as heart disease. The cohort had a mean age of 75.5 and a mean American Society of Anesthesiologists Physical Status (ASA-PS) score of 3.1. The patients were predicted to have a 2.74-fold increase of serious complications compared to the average patient. There were no adverse events. CONCLUSION: For patients with symptomatic, refractory DSD and relative contraindications to GA, SA may facilitate safe surgical intervention with excellent outcomes.

Novel Merging of CT and MRI to Allow for Safe Navigation into Kambin's Triangle for Percutaneous Lumbar Interbody Fusion-Initial Case Series Investigating Safety and Efficacy.

BACKGROUND: For percutaneous lumbar fusion (percLIF), magnetic resonance imaging and computed tomography are critical to defining surgical corridors. Currently, these scans are performed separately, and surgeons then use fluoroscopy or neuromonitoring to guide instruments through Kambin's triangle. However, anatomic variations and intraoperative positional changes are possible, meaning that safely accessing Kambin's triangle remains a challenge because nerveroot visualization without endoscopes has not been thoroughly described. OBJECTIVE: To overcome the known challenges of percLIF and reduce the likelihood of iatrogenic injuries by showing real-time locations of neural and bony anatomy. METHODS: The authors demonstrate an intraoperative navigational platform that applies nerve root segmentation and image fusion to assist with percLIF. Five patients from a single institution were included. RESULTS: Of the 5 patients, the mean age was 71 ± 8 years and 3 patients (60%) were female. One patient had general anesthesia while the remaining 4 patients underwent awake surgery with spinal anesthesia. The mean area for the L4-L5 Kambin's triangle was 76.1 ± 14.5 mm 2 . A case example is shown where the side of approach was based on the fact that Kambin's triangle was larger on one side compared with the other. The mean operative time was 170 ± 17 minutes, the mean blood loss was 32 ± 16 mL, and the mean hospital length of stay was 19.6 ± 8.3 hours. No patients developed postoperative complications. CONCLUSION: This case series demonstrates the successful and safe application of nerve segmentation using magnetic resonance imaging/computed tomography fusion to perform percLIF and provide positive patient outcomes.

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.

Instrument Tracking for Prone Lateral Surgery.

The prone lateral transpsoas approach for lumbar interbody fusion and posterior instrumentation enables a large surface area implant without disruption of the posterior spine musculature from a single position.1,2 The addition of virtual live fluoroscopy instrument tracking navigation to surgery provides multiple benefits, including a reduction in patient and surgeon radiation exposure, highly accurate and dynamic spatial tool localization, and flexible equipment and patient positioning.3,4 Here, we highlight the use of virtual live fluoroscopy in prone lateral spine surgery. A 75-year-old man presented with prior L3-L5 fusion and progressive lower extremity pain and weakness. Using the described techniques, the patient underwent a lateral retroperitoneal interbody fusion and posterior instrumentation at L2-L3. The operation proceeded without complication, and the patient reported improved ambulation at 6-week follow-up. The prone lateral transpsoas approach and minimally invasive posterior instrumentation for lumbar interbody fusion permits effective fusion without significant posterior muscle disruption from a single position. The integration of virtual live fluoroscopy enables real-time instrument tracking throughout the minimally invasive case, with reductions in patient and surgeon radiation exposure. Video 1 depicts the use and benefits of this technology in lateral spine surgery. Compared with computed tomography-guided navigation, virtual live fluoroscopy technology enables rapid remapping to iatrogenic anatomic changes for more fluid progression through the operation.5 Virtual live fluoroscopy instrument tracking is a valuable tool that increases the safety and efficiency of single-position lateral spine surgery.

Minimally invasive lateral retroperitoneal transpsoas approach for lumbar corpectomy and fusion with posterior instrumentation.

In this video, the authors highlight the operative treatment of a 55-year-old man with chronic osteomyelitis discitis. The operation entailed a minimally invasive lateral retroperitoneal transpsoas approach for L3 and L4 corpectomies, L2-5 interbody fusion, and L2-5 minimally invasive posterior instrumentation. The operation proceeded in two stages, beginning in the lateral position with corpectomy of the L3 and L4 vertebral bodies and placement of a corpectomy cage. After closure of this access wound, the patient was turned to a prone position for the posterior element of the operation. Posterior instrumentation was placed with pedicle screws at L2 and L5. The video can be found here: https://stream.cadmore.media/r10.3171/2022.3.FOCVID2210.

Beyond Placement of Pedicle Screws - New Applications for Robotics in Spine Surgery: A Multi-Surgeon, Single-Institution Experience.

Interest in robotic-assisted spine surgery has grown as surgeon comfort and technology has evolved to maximize benefits of time saving and precision. However, the Food and Drug Administration (FDA) has currently only approved robotics to assist in determining the ideal trajectory for pedicle screw placement after extensive research supporting its efficacy and efficiency. To be considered a durable and effective option, robotics need to expand beyond the indication of just placing pedicle screws. This article aims to illustrate a multi-surgeon, single-institution experience with unique applications of robotic technologies in spine surgery. We will explore accessing Kambin's Triangle in percutaneous transforaminal interbody fusion (percLIF), iliac fixation in metastatic cancer, and sacroiliac (SI) fusions. Each of these topics will be covered in depth with associated background information and subsequent discussion. We show that with proper understanding of its limitations, robots can help surgeons perform difficult surgeries in a safe manner.

Sacroiliac Joint Fusion Using Robotic Navigation: Technical Note and Case Series.

BACKGROUND: Patients undergoing sacroiliac (SI) fusion can oftentimes experience significant improvements in pain and quality of life. OBJECTIVE: To describe a novel application of robotic navigation to assist with minimally invasive SI joint fusion. METHODS: Patients undergoing stand-alone SI joint fusion with ExcelsiusGPS robotic navigation from July 2020 through June 2021 were retrospectively enrolled. Baseline demographic and perioperative variables including radiation exposure, postoperative pain scores, and narcotic requirements in the postanesthesia care unit (PACU) were recorded. Length of stay and any postoperative complications were also noted. RESULTS: A total of 10 patients (64.4 ± 8.2 years, body mass index 28.7 ± 4.8 kg/m2) met inclusion criteria. Seven patients (70.0%) were female, and there was a 6:4 split between left-sided and right-sided SI joint fusion. The total operative time was 54 ± 9 minutes, and the estimated blood loss was 21.0 ± 16.7 mL. The intraoperative radiation exposure was 13.7 ± 6.2 mGy, and there were no complications. The average pain score in PACU was 5.2 ± 1.0, and the average opioid administration in PACU was 27.6 ± 10.3 morphine equivalents. Length of stay was 0.4 ± 0.7 days, with 7 of 10 patients discharged on the same day as surgery. There were no readmissions. The average length of follow-up was 4.3 ± 2.5 months. At the last follow-up, patients reported an average of 73.1% ± 30.1% improvement in their preoperative pain. CONCLUSION: Robot-navigated SI joint fusion is a feasible and reproducible method for addressing refractory SI joint disease. Further investigation on clinical outcomes and long-term fusion rates is needed, as are studies comparing robot-navigated SI joint fusion with more traditional techniques.

Perioperative outcomes of general versus spinal anesthesia in the lumbar spine surgery population: A systematic review and meta-analysis of data from 2005 through 2021.

Study design: Meta-analysis. Objectives: Perform a systematic review and meta-analysis to determine the perioperative utility of general versus spinal anesthesia in the lumbar spine surgery population. Methods: PubMed and Embase were queried for manuscripts reporting perioperative outcomes for patients undergoing one to three-level lumbar spine surgery (including decompression, fusion, and decompression with fusion) using either general or spinal anesthesia. Inclusion criteria included studies published from 2005 to 2021, in English, involving primary data from human subjects. Studies were further screened for data on total operative time, blood loss, intraoperative hypotension, pain scores, postoperative nausea and vomiting, time required in post-anesthesia care unit (PACU), PACU pain anesthetic requirement, and length of stay. Risk of bias for each study was assessed using standardized tools (i.e., RoB 2, ROBINS-I, NOS, as appropriate). Potential predictors of outcome were compared using univariate analysis, and variables potentially associated with outcome were subjected to meta-analysis using Cochran-Mantel-Haenszel testing to produce standard mean differences (SMD) or odds ratios (OR) and 95% confidence intervals (CI). Results: In total, 12 studies totaling 2796 patients met inclusion criteria. 1414 (50.6%) and 1382 (49.4%) patients underwent lumbar spine surgery with general anesthesia and spinal anesthesia, respectively. Patients undergoing spinal anesthesia were statistically more likely to have coronary artery disease and respiratory dysfunction. Total operative time (SMD: 12.62 min, 95% CI -18.65 to -6.59), estimated blood loss (SMD: 0.57 mL, 95% CI -0.68 to -0.46), postoperative nausea and vomiting (OR = 0.20, 95% CI 0.15 to 0.26), time required in PACU (SMD = -0.20 min, 95% CI -0.32 to -0.08), and length of stay (SMD = -0.14 day, 95% CI -0.18 to -0.10), all statistically significantly favored spinal anesthesia over general anesthesia (p < 0.05). Conclusion: In one to three-level lumbar spine surgery, current literature supports spinal anesthesia as a viable alternative to general anesthesia. As this was a heterogeneous patient population, prospective randomized trials are needed to corroborate findings.

Single-position prone transpsoas fusion for the treatment of lumbar adjacent segment disease: early experience of twenty-four cases across three tertiary medical centers.

PURPOSE: Prone transpsoas fusion (PTP) is a minimally invasive technique that maximizes the benefit of lateral access interbody surgery and the prone positioning for surgically significant adjacent segment disease. The authors describe the feasibility, reproducibility and radiographic efficacy of PTP when performed for cases of lumbar ASD. METHODS: Adult patients undergoing PTP for treatment of lumbar ASD at three institutions were retrospectively enrolled. Demographic information was recorded, as was operative data such as adjacent segment levels, operative time, blood loss, laterality of approach, open versus percutaneous pedicle screw instrumentation and need for primary decompression. Radiographic measurements including segmental and global lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope and sagittal vertical axis were recorded both pre- and immediately post-operatively. RESULTS: Twenty-four patients met criteria for inclusion. Average age was 60.4 ± 10.4 years and average BMI was 31.6 ± 5.0 kg/m2. Total operative time was 204.7 ± 83.3 min with blood loss of 187.9 ± 211 mL. Twenty-one patients had pedicle screw instrumentation exchanged percutaneously and 3 patients had open pedicle screw exchange. Two patients suffered pulmonary embolism that was treated medically with no long-term sequelae. One patient had transient lumbar radicular pain and all patients were discharged home with an average length of stay of 3.0 days (range 1-6). Radiographically, global lumbar lordosis improved by an average of 10.3 ± 9.0 degrees, segmental lordosis by 10.1 ± 13.3 degrees and sagittal vertical axis by 3.2 ± 3.2 cm. CONCLUSION: Single-position prone transpsoas lumbar interbody fusion is a clinically reproducible minimally invasive technique that can effectively treat lumbar adjacent segment disease.

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.