Medium Term Outcomes in Palliative Transpedicular Corpectomy with Cement Based Anterior Vertebral Reconstruction Performed for Patients with Spinal Metastasis.

STUDY DESIGN: Retrospective. OBJECTIVE: Assess the outcomes of single stage posterior transpedicular corpectomy with cement-based anterior column support for spinal metastasis at longer follow-ups. SUMMARY OF BACKGROUND DATA: Life expectancy of cancer patients is constantly increasing. Reliable anterior column reconstruction after posterior corpectomy becomes necessary. METHODS: In this retrospective monocentric study, patients who underwent posterior transpedicular corpectomy and cement-based anterior reconstruction, with a minimum 6 months follow-up, were included. Ambulatory status and pain visual analog score(PVAS), complication rates and Local Sagittal Cobb angle (LSA) were evaluated preoperatively, postoperatively and at the latest follow-up. RESULTS: In total, 253 patients were included, with a mean follow-up of 21 months [6-132] and a median survival of 9 months. Pre-operatively, 202 patients(81%) were ambulant while 47 patients (19%) weren't. At the latest follow-up, 241 patients (95%) were ambulant while 12 patients(5%) weren't (P<0.001). Dorsal/lumbar PVAS went from 8.2±2.2 pre-operatively to 5.2(±1.7) post-operatively reaching 3.4±1.9 at the latest follow-up (P<0.001). Mean LSA decreased from 13.2°(±5.78) pre-operatively to 6.11°(±8.51)(P<0.001) post-operatively and reached 7.56°(±7.55) at the latest follow-up(P=0.59). Complications occurred in 39(15.4%) patients. One-third of those were mechanical(rod/screw fracture, cement displacement) needing re-intervention in 4 patients(1.6%). CONCLUSIONS: The mechanical stability offered by the cement-based anterior reconstruction is maintained during the lifespan of patients operated for the spinal metastasis. Satisfying functional and radiological outcomes observed at the last follow-up show that this lasting, cost sparing, and relatively simple reconstruction technique, is a valid alternative for the costly and more complicated cage-based reconstruction.

Clinical and radiological outcomes of gradual reduction and circumferential fusion of high-grade spondylolisthesis in adolescents: a prospective cohort study of 29 young patients.

AIM: The objective of this study was to evaluate the safety and efficacy of a novel technique of formal reduction and circumferential fusion for pediatric high-grade spondylolisthesis (HGS). PURPOSE: The safety and efficacy of formal reduction for high-grade spondylolisthesis (HGS) has never been thoroughly examined. This study reports the outcomes of 29 children with HGS who underwent a procedure of gradual reduction and circumferential fusion. METHODS: 29 children (13 males, 16 females) were recruited between 2006 and 2010. Radiographic measurements (including % of slip, lumbosacral angle-LSA, pelvic incidence-PI, pelvic tilt-PT, sacral slope-SS, and proximal femoral angle-PFA) and quality of life assessment (SRS-22 questionnaire) were prospectively obtained at baseline and at the last post-operative follow-up (> 2 years post-op). Radiological measurements were used to classify patients according to the Spine Deformity Study Group (SDSG) classification. RESULTS: Mean baseline slip % was 69.9 ± 16.5%. There were 13 patients with a balanced pelvic (SDSG Type 4) and 16 with an unbalanced pelvis (SDSG Type 5 and 6). On average, a reduction of 45.5 ± 15.3% (range 20-86%) was achieved safely with no major complication. In particular, of the 29 patients, only 3 had a L5 radiculopathy postoperatively that was self-resolved at follow-up. From a radiological standpoint, we observed a mean improvement of LSA from 80.3 ± 17.9° to 91.7 ± 13.6°. We also observed a statistically significant improvement in global HRQOL, and in the function and body image domains. CONCLUSION: This prospective study suggests that formal reduction of HGS followed by circumferential fusion is safe when using a standardized surgical technique based on gradual reduction. Performing this intervention could also help improve QOL in some patients.

Ovine model of congenital chest wall and spine deformity: From birth to 3 months follow-up.

Background: The evolution and treatment of lung alterations related to congenital spine and chest wall deformities (CWD) are poorly understood. Most animal models of CWD created postnatally were not evaluated for respiratory function. The goal of our study was to evaluate the effects of a CWD induced in utero on lung growth and function in an ovine model. Methods: A CWD was induced in utero at 70-75 days of gestation in 14 ovine fetuses by resection of the 7th and 8th left ribs. Each non-operated twin fetus was taken as control. Respiratory mechanics was studied postnatally in the first week and at 1, 2, and 3 months. Post-mortem respiratory mechanics and lung histomorphometry were also assessed at 3 months. Results: Eight out of 14 CWD lambs (57%) and 14 control lambs survived the postnatal period. One severe and five mild deformities were induced. At birth, inspiratory capacity (25 vs. 32 mL/kg in controls), and dynamic (1.4 vs. 1.8 mL/cmH2O/kg), and static (2.0 vs. 2.5 mL/cmH2O/kg) respiratory system compliances were decreased in CWD lambs. Apart from a slight decrease in inspiratory capacity at 1 month of life, no other differences were observed in respiratory mechanics measured in vivo thereafter. Postmortem measurements found a significant decrease in lung compliance-for each lung and for both lungs taken together-in CWD lambs. No differences in lung histology were detected at 3 months in CWD animals compared to controls. Conclusions: Our study is the first to assess the effects of a prenatally induced CWD on lung development and function from birth to 3 months in an ovine model. Our results show no significant differences in lung histomorphometry at 3 months in CWD lambs compared to controls. Resolution at 1 month of the alterations in respiratory mechanics present at birth may be related to the challenge in inducing severe deformities.

Can Pelvic Incidence Change After Lumbo-Pelvic Fixation for Adult Spine Deformity, and Would the Change be Affected by the Type of Pelvic Fixation?

STUDY DESIGN: Retrospective review. OBJECTIVE: To assess the change in pelvic incidence (PI) after lumbo-pelvic fixation and the differential impact of the type of pelvic fixation: S2-alar-iliac screws (S2AI) versus Iliac screws (IS) on postoperative PI. SUMMARY OF BACKGROUND DATA: Recent studies suggest that changes occur to the previously assumed fixed PI after spino-pelvic fixation. METHODS: Adult spine deformity (ASD) patients who underwent spino-pelvic fixation with≥4 levels of fusion were included. Preoperative and postoperative PI, lumbar lordosis (LL), thoracic kyphosis, pelvic tilt, sacral slope, PI-LL mismatch, and the Sagittal Vertical Axis (SVA) were analyzed on EOS imaging. A significant PI change was established at≥6°. Patients were categorized based on the type of pelvic fixation (S2AI vs. IS). RESULTS: One-hundred-forty-nine patients were included. Of these, 77(52%) had a>6° change in their PI postoperatively. In patients with high preoperative PI (>60°), 62% had a significant PI change compared with 33% of patients with normal PI (40°-60°) and 53% in patients with low PI (<40°; P =0.01). PI was likely to decrease in patients with high baseline PI (>60°) and to increase in patients with low baseline PI (<40°). Patients with a significant PI change had a higher PI-LL. Patients in the S2AI group (n=99) and those in the IS group (n=50) were comparable at baseline. In the S2AI group, 50 (51%) patients had>6° change in their PI compared with 27(54%) patients in the IS group( P =0.65). In both groups, patients with high preoperative PI were more prone to significant postoperative changes ( P =0.02 in IS, P =0.01 in S2AI). CONCLUSION: PI changed significantly in 50% of patients postoperatively, especially in those with high/low preoperative PI and those with severe baseline sagittal imbalance. This occurs similarly in patients with S2AI and those with IS screws. Surgeons should keep in mind these anticipated changes while planning ideal LL, as this impacts postoperative PI-LL mismatch. LEVEL OF EVIDENCE: 4.

Early Compensatory Segmental Angle Changes at L3-4 and L4-5 Following a L5-S1 Interbody Fusion for a Grade 1 Spondylolisthesis.

STUDY DESIGN: Retrospective study included patients who underwent a L5-S1 ALIF or TLIF with posterior pedicle screw instrumentation for grade 1 spondylolisthesis 2018-2022. OBJECTIVE: To compare early reciprocal changes at the L3-4 and L4-5 adjacent levels six months after anterior (ALIF) or transforaminal (TLIF) lumbar interbody fusion at L5-S1. BACKGROUND: Degenerative and chronic isthmic spondylolistheses often result in decreased segmental lordosis at L5-S1. This can lead to lordotic overcompensation at adjacent levels to maintain spinopelvic balance. However, the fate of adjacent angles following interbody fusion is not well understood. METHODS: Preoperative and 6-month postoperative measurements of segmental lordosis (L3-4, L4-5, and L5-S1), lumbar lordosis, and pelvic incidence were obtained from sagittal standing radiographs. Preliminary t-tests were performed for descriptive purposes, and multiple regression was used for hypothesis testing. RESULTS: Ninety-eight patients met the inclusion criteria (50 ALIF and 48 TLIF). A greater amount of lordosis achieved at L5-S1 was significantly associated with a greater reduction of segmental lordosis at L4-5 (r=-0.65, P<.001) or L3-4 (r=-0.46, P<.001) (Fig. 3A). A greater preoperative PI was associated with a greater reduction of segmental lordosis at L4-L5 (r=-0.42, P<.001) and at L3-L4 (r=-0.44, P<.001). CONCLUSION: At six months following a lumbar interbody fusion at L5-S1, greater compensatory changes with lordosis reduction are observed at the supra-adjacent L4-5 and L3-4 levels in patients achieving greater L5-S1 segmental lordosis. Additionally, preoperative pelvic incidence (PI) played a role in influencing lordotic correction.

Pneumorrhachis and pneumocephalus resulting from pneumothorax: illustrative case.

BACKGROUND: Pneumorrhachis and pneumocephalus are rare conditions in which air is found within the spinal canal and brain, respectively. It is mostly asymptomatic and can be located in the intradural or extradural space. Intradural pneumorrhachis should prompt clinicians to search and treat any underlying injury of the skull, chest, or spinal column. OBSERVATIONS: A 68-year-old man presented with a history of cardiopulmonary arrest together with pneumorrhachis and pneumocephalus following a recurrent pneumothorax. The patient reported acute headaches with no other neurological symptoms. He was managed conservatively with bed rest for 48 hours following thoracoscopic talcage of his pneumothorax. Follow-up imaging showed regression of the pneumorrhachis, and the patient reported no other neurological symptoms. LESSONS: Pneumorrhachis is an incidental radiological finding that self-resolves with conservative management. However, it can be a complication resulting from a serious injury. Therefore, close monitoring of neurological symptoms and complete investigations should be performed in patients with pneumorrhachis.

Personalized Medicine in Orthopaedic Surgery: The Case of Spine Surgery.

Personalized medicine has made a tremendous impact on patient care. Although initially, it revolutionized pharmaceutical development and targeted therapies in oncology, it has also made an important impact in orthopaedic surgery. The field of spine surgery highlights the effect of personalized medicine because the improved understanding of spinal pathologies and technological innovations has made personalized medicine a key component of patient care. There is evidence for several of these advancements to support their usage in improving patient care. Proper understanding of normative spinal alignment and surgical planning software has enabled surgeons to predict postoperative alignment accurately. Furthermore, 3D printing technologies have demonstrated the ability to improve pedicle screw placement accuracy compared with free-hand techniques. Patient-specific, precontoured rods have shown improved biomechanical properties, which reduces the risk of postoperative rod fractures. Moreover, approaches such as multidisciplinary evaluations tailored to specific patient needs have demonstrated the ability to decrease complications. Personalized medicine has shown the ability to improve care in all phases of surgical management, and several of these approaches are now readily available to orthopaedic surgeons.

What is the fate of the adjacent segmental angles 6 months after single-level L3-4 or L4-5 lateral lumbar interbody fusion?

BACKGROUND CONTEXT: Lateral lumbar interbody fusion (LLIF) is an effective technique for fusion and sagittal alignment correction/maintenance. Studies have investigated the impact on the segmental angle and lumbar lordosis (and pelvic incidence-lumbar lordosis mismatch), however not much is documented regarding the immediate compensation of the adjacent angles. PURPOSE: To evaluate acute adjacent and segmental angle as well as lumbar lordosis changes in patients undergoing a L3-4 or L4-5 LLIF for degenerative pathology. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: Patients included in this study were analyzed pre- and post-LLIF performed by one of three fellowship-trained spine surgeons, 6 months following surgery. OUTCOME MEASURES: Patient demographics (including body mass index, diabetes diagnosis, age, and sex) as well as VAS and ODI scores were measured. Lateral lumbar radiograph parameters: lumbar lordosis (LL), segmental lordosis (SL), infra and supra-adjacent segmental angle, and pelvic incidence (PI). METHODS: Multiple regressions were applied for the main hypothesis tests. We examined any interactive effects at each operative level and used the 95% confidence intervals to determine significance: a confidence interval excluding zero indicates a significant effect. RESULTS: We identified 84 patients who underwent a single level LLIF (61 at L4-5, 23 at L3-4). For both the overall sample and at each operative level, the operative segmental angle was significantly more lordotic postop compared to preop (all ps≤.01). Adjacent segmental angles were significantly less lordotic postop compared to pre-op overall (p=.001). For the overall sample, greater lordotic change at the operative segment led to more compensatory reduction of lordosis at the supra-adjacent segment. At L4-5, more lordotic change at the operative segment led to more compensatory lordosis reduction at the infra-adjacent segment. CONCLUSION: The present study demonstrated that LLIF resulted in significant increase in operative level lordosis and a compensatory decrease in supra- and infra-adjacent level lordosis, and subsequently no significant impact on spinopelvic mismatch.

Incidence, etiology and time course of delays to adult spinal deformity surgery: a single-center experience.

PURPOSE: We sought to determine the incidence, origin, and timeframe of delays to adult spinal deformity surgery so that institutions using preoperative multidisciplinary patient assessment teams might better anticipate and address these potential delays. METHODS: Complex spine procedures for treatment of adult spinal deformity from 1/1/18 to 8/31/21 were identified. Procedures for infection, tumor, and urgent/emergent cases were excluded. Operations delayed due to COVID or those that were performed outside of our established perioperative care pathway were also excluded. The electronic health record was used to identify the etiology and timeline of all pre- and peri-operative delays. RESULTS: Of 235 patients scheduled for complex spine surgery, 193 met criteria for inclusion. Of these patients, 35 patients experienced a surgical delay (18.1%) with a total of 41 delays recorded. Reasons for delay include medically unoptimized (25.6%), intraoperative complication (17.9%), patient directed delay (17.9%), patient illness/injury (15.4%), scheduling complication (10.3%), insurance delay/denial (5.1%), and unknown (2.6%). Twenty-four delays experienced by 22 individuals occurred within 7 days of their scheduled surgery date. CONCLUSION: At a single multidisciplinary center, most delays to adult spinal deformity surgery occur before a patient is admitted to the hospital, and for recommendations of additional medical workup/clearance. We suspect that the preoperative protocol might increase pre-admission delays for unoptimized patients, as the protocol is intended to ensure patients receive surgery only when they are medically ready. Further research is needed to determine the economic and system impact of delays related to a preoperative optimization protocol weighed against the reduction in adverse events these protocols can provide.

Use of Cannulated Reamers to Facilitate Thoracic Diskectomy Using a Minimally Invasive Retropleural Thoracotomy Approach-Surgical Technique.

BACKGROUND: The surgical treatment of symptomatic thoracic disk herniations is technically challenging. In the past decade, a minimally invasive retropleural thoracotomy approach has become more popular to treat this pathology. However, efficient bone removal to safely perform the diskectomy and spinal cord decompression is difficult with this technique because of the small incision size and long working distance in the thoracic cavity and the proximity of the compressed thoracic cord. OBJECTIVE: To describe a novel surgical technique for performing a thoracic diskectomy using a minimally invasive lateral approach using cannulated reamers to facilitate bone removal. METHODS: This technique was used in 7 consecutive patients who presented with thoracic myelopathy from a thoracic disk herniation. First, a standard lateral minimally invasive retropleural approach to the thoracic spine was performed. Partially threaded guide wires were placed in the posterior aspect of the vertebral bodies adjacent to the affected disk space, and sequential cannulated reamers were passed over the guidewires to perform partial corpectomies. The posterior annulus, posterior longitudinal ligament, and herniated disk material were then resected using Penfield dissectors and Kerrison rongeurs to complete the decompression. RESULTS: All 7 patients who underwent thoracic diskectomy using this approach had stable or improved neurologic function postoperatively. There were no complications related to the use of the cannulated reamer technique. CONCLUSION: The use of cannulated reamers provides a simple and efficient method for safe bone removal to facilitate minimally invasive thoracic diskectomy using a lateral approach. This is an easily reproducible technique using commonly available equipment.

Which Scoring System Is the Most Accurate for Assessing Survival Prognosis in Patients Undergoing Surgery for Spinal Metastases from Lung Cancer? A Single-Center Experience.

OBJECTIVE: To compare different survival prognosis scores among patients operated on for spinal metastasis from lung cancer. METHODS: A single-center retrospective review of patients with lung cancer and spinal metastases who underwent spinal surgery at our institution from January 2008 to October 2020 was conducted. We calculated the prognostic value of the following scoring systems: revised Tokuhashi, revised Bauer, Skeletal Oncology Research Group classic, and New England Spinal Metastatic Score. For each scoring system, discrimination was assessed by computing the area under the curve. RESULTS: The study included 94 patients operated on for spinal metastasis from lung cancer. Mean patient age was 62 years (range, 32-79 years); 51% of patients were male. The 1-year survival rate was 18%, and the median survival time was 4 months. The 6- and 12-month area under the curve was 60% and 76%, respectively, for revised Tokuhashi, 55% and 58% for revised Bauer, 58% and 63% for Skeletal Oncology Research Group classic, and 61% and 69% for New England Spinal Metastatic Score. CONCLUSIONS: The revised Tokuhashi score seemed to be the most accurate scoring system for assessing survival prognosis in patients operated on for spinal metastasis from lung cancer. Newer scores including biological parameters did not add further precision among this specific population.

Combining time-driven activity-based costing and lean methodology: an initial study of single-level lumbar fusion surgery to assess value-based healthcare in patients undergoing spine surgery.

OBJECTIVE: Measuring costs across entire episodes of care, time-driven activity-based costing (TDABC) has recently been described as a novel cost accounting arm of value-based care organizations. Lean methodology is a system used to understand pathways of care at a granular level, allowing for standardization. The current work presents an attempt at combining the 2 methodologies to detect meaningful variation in a patient's care following single-level spine fusion. The objective of this study was to evaluate the combination of TDABC and lean methodologies in detecting meaningful variability in time-based care in patients undergoing single-level spine fusion surgery. METHODS: This study is a consecutive case series of patients who underwent single-level spine fusion performed by 1 of 5 fellowship-trained spine surgeons. Patients were diagnosed with either lumbar stenosis or spondylolisthesis. Additional inclusion criteria included inpatient stays from 1 to 3 days, discharge to home, and no readmission within 30 days of surgery. Patient demographic data were obtained. Time spent on activities for each personnel role was aggregated in 15-minute increments occurring preoperatively, intraoperatively, and postoperatively. Patients were analyzed in 3 groups based on the duration of their in-hospital stay. RESULTS: Patients discharged on postoperative day (POD) 3 had statistically significantly more total time spent than those discharged on POD 2. Patients discharged on POD 1 had less total time than those in the former 2 groups. The amount of time spent with patients did not differ for personnel in either preoperative or postanesthesia care unit phases of care. There was a statistically significant difference in time spent in surgery for surgeons, anesthesia attendings, circulators, and scrub technicians. CONCLUSIONS: In a healthcare setting run by lean methodology, TDABC may detect meaningful variability in an episode of care for single-level spine fusion. Clinicians and administrators can use this combination to allocate costs appropriately, optimize value care streams, and help improve patient care.

The Impact of Surgical Approach on Sagittal Plane Alignment in Patients Undergoing One- or Two- Level Fusions for Degenerative Pathology: A Multicenter Radiographic Evaluation 6 Months Following Surgery.

OBJECTIVE: Interbody fusion procedures, including transforaminal (TLIF), posterior (PLIF), anterior (ALIF), and lateral (LLIF), effectively treat lumbar degenerative pathology and provide spinopelvic balance. The objective of this study is to compare changes in spinopelvic parameters 6 months following 1-2 level TLIF, PLIF, ALIF, and LLIF. METHODS: This retrospective study included 18 centers across the United States. Patients were included in the study if they underwent a 1- or 2-level primary lumbar fusion for degenerative pathology. Preoperative and 6-month postoperative lumbar anteroposterior and lateral lumbar plain radiograph measurements included: pelvic incidence, pelvic tilt, lumbar lordosis from L1-S1, and segmental lordosis of each segment between L1 and S1. RESULTS: A total of 474 patients met inclusion criteria, with 632 levels that underwent fusion. Of these, 181 patients underwent an ALIF/LLIF on 381 levels, and 188 underwent a TLIF/PLIF on 252 levels. ALIF/LLIF procedures resulted in significantly more segmental lordosis (P < 0.001) and global lumbar lordotic alignment change (P < 0.01) compared with TLIF/PLIF procedures. Whether patients' alignment was preserved versus worsened was not significantly predicted by type of procedure. Similarly, whether patients' alignment was restored versus not corrected was not significantly predicted by procedure. CONCLUSIONS: In this large-scale multicenter study of lumbar fusion patients presenting with degenerative lumbar pathology, anteriorly placed grafts (ALIF/LLIF) led to a greater likelihood of patients being preserved rather than worsened in their spinopelvic mismatch. Posteriorly placed TLIF or PLIF grafts tended to worsen lordosis both segmentally and globally, yet even the anterior grafts only modestly improved those 2 same measurements.

Simulation Training in Spine Surgery.

Simulated surgery is part of a growing paradigm shift in surgical education as a whole. Various modalities from cadaver models to virtual reality have been developed and studied within the context of surgical education. Simulation training in spine surgery has an immense potential to improve education and ultimately improve patient safety. This is due to the inherent risk of operating the spine and the technical difficulty of modern techniques. Common procedures in the modern orthopaedic armamentarium, such as pedicle screw placement, can be simulated, and proficiency is rapidly achieved before application in patients. Furthermore, complications such as dural tears can be simulated and effectively managed in a safe environment with simulation. New techniques with steeper learning curves, such as minimally invasive techniques, can now be safely simulated. Hence, augmenting surgical education through simulation has great potential to benefit trainees and practicing orthopaedic surgeons in modern spine surgery techniques. Additional work will aim to improve access to such technologies and integrate them into the current orthopaedic training curriculum.

The impact of interbody approach and lumbar level on segmental, adjacent, and sagittal alignment in degenerative lumbar pathology: a radiographic analysis six months following surgery.

BACKGROUND CONTEXT: Interbody fusion, including: transforaminal (TLIF), posterior (PLIF), anterior (ALIF), and lateral (LLIF); effectively treat lumbar degenerative pathology and provide spinopelvic balance. Although the decision on surgical approach and technique are multifactorial and patient specific, the impact of the interbody approach on segmental and adjacent level lordosis could be an important factor to consider during pre-operative planning to achieve pre-specified alignment goals. PURPOSE: The purpose of this study is to compare the 6-month postoperative radiographic outcomes in the lumbar spine following 1 to 2 level transforaminal (TLIF), posterior (PLIF), anterior (ALIF), and lateral (LLIF) interbody fusions at the L3-4, L4-5, and L5-S1 levels. As our primary outcome, we evaluated the change in segmental lordosis at the level of fusion in ALIF/LLIF approaches compared to TLIF/PLIF. Secondarily, we evaluated the pelvic incidence to lumbar lordosis (PI-LL) mismatch and examined the compensatory lordotic changes at the adjacent levels 6 months following surgery. STUDY DESIGN: Retrospective cohort. PATIENT SAMPLE: This retrospective study included 18 centers of various practice settings across the United States. Patients were included in the study if they underwent a one- or two-level primary lumbar fusion for degenerative pathology. OUTCOMES MEASURES: Measurements of the pre-operative and 6-month post-operative lumbar AP and lateral lumbar plain radiographs included: pelvic incidence (PI), pelvic tilt, lumbar lordosis from L1-S1 (LL), as well as segmental lordosis (SL) of each segment between L1-S1. METHODS: Due to there being 2 evaluated time points, patients were then grouped based on alignment into categories of preserved, restored, not corrected, and worsened. RESULTS: 474 patients underwent 608 levels of fusion. ALIF/LLIF resulted in significantly more segmental lordosis compared to TLIF/PLIF procedures at both L4-5 and L5-S1 (p<.001). Overall, ALIF/LLIF resulted in significantly more global lumbar lordotic alignment change compared to TLIF/PLIF (p=.01). Whether patients' alignment was preserved versus worsened was not significantly predicted by type of procedure. Similarly, whether patients' alignment was restored versus not corrected was not significantly predicted by type of procedure. Finally, anterior approaches resulted in decreased lordosis at adjacent levels, thus resulting in a more neutral position. CONCLUSION: In this large multicenter retrospective study of 1 to 2 level interbody fusion surgeries, we identified that A/LLIF procedures at L4-L5 and L5-S1 resulted in greater segmental lordosis restoration and PI-LL mismatch improvement compared to T/PLIF procedures. A/LLIF may also significantly reduce lordosis (compared to T/PLIF) at the adjacent levels in a fashion that serves to reduce the lumbar lordosis that may have been increased at the fused level.

fM-aM Detection of the SARS-CoV-2 Antigen by Advanced Lateral Flow Immunoassay Based on Gold Nanospheres.

The SARS-CoV-2 global pandemic created an unprecedented need for rapid, sensitive, and inexpensive point-of-care (POC) diagnostic tests to treat and control the disease. Many POC SARS-CoV-2 lateral flow immunoassays (LFAs) have been developed and/or commercialized, but with only limited sensitivity (µM-fM). We created an advanced LFA based on gold nanospheres (GNSs) with comprehensive assay redesign for enhanced specific binding and thermal contrast amplification (TCA) on GNSs for signal amplification, which enabled fM-aM detection sensitivity for SARS-CoV-2 spike receptor-binding domain (RBD) proteins within 30 min. The advanced LFA can visually detect RBD proteins down to 3.6 and 28.6 aM in buffer and human nasopharyngeal wash, respectively. This is the first reported LFA achieving sensitivity comparable to that of the PCR (aM-zM) by visual reading, which was much more sensitive than traditional LFAs. We also developed a fast (<1 min) TCA reading algorithm, with results showing that this TCA could distinguish 26-32% visual false negatives for clinical commercial LFAs. When our advanced LFAs were applied with this TCA, the sensitivities were further improved by eightfold to 0.45 aM (in buffer) and 3.6 aM (in the human nasopharyngeal wash) with a semiquantitative readout. Our proposed advanced LFA with a TCA diagnostic platform can help control the current SARS-CoV-2 pandemic. Furthermore, the simplicity and speed with which this assay was assembled may also facilitate preparedness for future pandemics.

Iatrogenic dural tear after growth modulation in AIS: an unusual complication and its management.

PURPOSE: To report a case of iatrogenic durotomy with symptomatic Chiari-like deformity in a patient after undergoing anterior vertebral body growth modulation (AVBGM) in skeletally immature patients with adolescent idiopathic scoliosis (AIS). There have not been reports of iatrogenic durotomy in the literature and its management after AVBGM. METHODS: A 13-year-old skeletally immature girl underwent successful AVBGM for thoracic AIS from T6 to T12. Despite uneventful post-operative hospitalization, the patient suffered from recurrent and persistent bouts of headaches that were mostly orthostatic. At 3 months post-op, an MRI was performed on the suspicion of a cerebrospinal fluid (CSF) leak due to an iatrogenic durotomy. On MRI, decreased volume of CSF and a decrease in the dural sac diameter were observed. Furthermore, a pseudo-meningocele was seen at the last level of instrumentation. RESULTS: After an unsuccessfully trial of epidural blood patch combined with 5 days of supine immobilization, the patient was consented to screw revision as well as a lumbar drain. The lumbar drain was installed to redirect the CSF leak to allow the durotomy to heal. After 11 days, the drain was removed based on the favorable clinical evolution. CONCLUSION: Iatrogenic durotomy is a rare complication in AVBGM. This is the first report of such a case that involves a Chiari-like deformity on initial MRI investigation. We suggest that an MRI is performed for all patients presenting with symptoms of CSF leak after AVBGM.

True 3D parameters of the spinal deformity in adolescent idiopathic scoliosis.

BACKGROUND: Spinal deformities in adolescent idiopathic scoliosis (AIS) are measured on 2D radiographs. Due to the 3D nature of the curve in AIS, such 2D measurements fail to differentiate between the true curve patterns, which in turn may adversly impact the clinical care and surgical planning. The use of 3D models of the spinal radiographs largely remains limited to the 3D measurements of the 2D parameters. The use of the true 3D variables of the spinal curves in describing the differences between the AIS patients is not fully explored. METHODS: A cohort of 141 Lenke 1 AIS with two-view spinal stereoradiographs and 3D models of the spines were included. The 3D model of the spine was used to determine the spinal centerlines. The writhe and torsion of the 3D centerlines, which, respectively, quantify the coiling and twist of the curve, were calculated using differential geometry. Patients were clustered based on the writhe and torsion values to determine the patient groups with significantly different 3D curve characteristics. The relationship between the writhe and torsion was statistically determined. The distribution of the writhe and torsion groups between the lumbar modifier types was determined. RESULTS: Two writhe and two torsion clusters were determined. Lumbar orientation of plane of maximum curvature (PMC) was significantly different between the torsion clusters and thoracic and lumbar PMC and thoracic Cobb angles were significantly different between the writhe groups, p < 0.05. More than 50% of the patients had high writhe and low torsion except for Lumbar modifier C that mainly belonged to the low writhe group. DISCUSSION: Two geometrical parameters of the spinal centerline determine true 3D characteristics of the scoliotic curves. The parameters were complimentary and weakly correlated, quantifying different characteristics of the scoliotic spines.

Surgical Intervention for Patients With Spinal Metastasis From Lung Cancer: A Retrospective Study of 87 Cases.

STUDY DESIGN: This was a retrospective study. OBJECTIVE: Evaluate the prognosis and surgical outcomes of patients with spinal metastasis from lung cancer undergoing surgical treatment. SUMMARY OF BACKGROUND DATA: The spine is the most common site of metastatic lesions in patients with lung cancer. There have been a few studies, all small cohorts studying prognosis and surgical outcomes and the results were discordant. MATERIALS AND METHODS: A retrospective study on a prospectively collected database was conducted. Data collected were the following: age, tobacco use, tumor histology, American Spinal Injury Association score, revised Tokuhashi score, ambulatory status, perioperative complications, postoperative adjuvant treatment, and survival time. Univariate and multivariate analyses were performed to identify the prognostic factors of survival. RESULTS: The authors studied 87 patients with a mean age of 61.3±1.9 years. Median survival was 4.1±0.8 months. Twenty-eight patients (32.2%) lived >6 months and 14 patients (16.1%) lived >12 months. The medical complication rate was 13.8% and the surgical complication rate was 5.7%. The 30-day mortality rate was 4.6%. Univariate analysis showed tobacco use, revised Tokuhashi score, preoperative and postoperative American Spinal Injury Association score, postoperative walking ability, postoperative radiotherapy, and postoperative chemotherapy were prognostic factors. There was no significant difference in survival between adenoma lung cancers, nonadenoma lung cancers, and small cell lung cancers (P=0.51). Multivariate analysis revealed tobacco use, revised Tokuhashi score, postoperative walking ability, postoperative radiotherapy, and postoperative chemotherapy affected the survival. CONCLUSIONS: This is the largest reported study of patients with spinal metastasis from lung cancer undergoing spinal surgery. It is the first study showing that tobacco use has a negative impact on survival. Spinal surgery improves the quality of life and offers nonambulatory patients a high chance of regaining walking ability with an acceptable risk of complications.

Anterior Vertebral Body Growth-Modulation Tethering in Idiopathic Scoliosis: Surgical Technique.

The management of idiopathic scoliosis in the skeletally immature patient can be challenging. Posterior spinal fusion and instrumentation is indicated for severe scoliosis deformities. However, the skeletally immature patient undergoing posterior fusion and instrumentation is at risk for developing crankshaft deformities. Moreover, bracing treatment remains an option for patients who are skeletally immature, and although it was found to be effective, it does not completely preclude deformity progression. Recently, fusionless treatment options, such as anterior vertebral body growth modulation, have been developed to treat these patients while avoiding the complications of posterior rigid fusion. Good results have been shown in recent literature with proper indications and planning in the skeletally immature patient.