BACKGROUND CONTEXT The anterior-to-psoas (ATP) interbody fusion approach enables minimally invasive access to lumbar disc spaces from L2 to L5. When combined with lateral anterior lumbar interbody fusion (ALIF) at L5/S1, multilevel constructs can be performed in a single lateral position followed by posterior spinal fusion. PURPOSE To evaluate blood loss, complications, and patient-reported outcomes (PROMs) across ATP, lateral ALIF, and combined approaches. STUDY DESIGN/SETTING Retrospective review of 467 consecutive patients undergoing ATP and lateral ALIF by a single surgeon. PATIENT SAMPLE A total of 467 patients: 232 ATP-only, 56 lateral ALIF-only, and 179 combined ATP + lateral ALIF procedures. OUTCOME MEASURES PROMs including VAS back pain, VAS leg pain, Oswestry Disability Index (ODI), and EQ-5D assessed preoperatively and up to 1 year postoperatively. METHODS Patients were grouped by surgical approach and posterior fusion length (1–3, 4–8, >8 levels). Statistical analyses included Kruskal-Wallis, Mann-Whitney U, chi-square, and Wilcoxon signed-rank tests. RESULTS Mean ATP estimated blood loss (EBL) for single-level procedures was 40±35 mL, with no difference across levels (p=0.289). Four-level constructs (L2–S1) had higher EBL (109±74 mL, p<0.001) but remained clinically modest. Lateral ALIF complication rate was 2.6%, with vascular injury most common (0.9%). ATP complication rate was 1.3%. Posterior EBL increased with construct length (p<0.001). PROMs improved significantly at 1 year: VAS back pain (6.8→3.7), VAS leg pain (5.4→2.5), ODI (49.5→33.3), and EQ-5D (0.5→0.7) (all p<0.001). Extending constructs to four levels did not increase complication rates. CONCLUSIONS ATP and lateral ALIF approaches demonstrate low blood loss and complication rates across varying construct lengths, with significant improvements in patient-reported outcomes. These findings support the safety and efficacy of ATP-based multilevel lumbar reconstruction, including L5/S1 access, with same-day posterior stabilization. FDA Device/Drug Status O-arm Surgical Imaging System with StealthStation Navigation (Medtronic); Clydesdale, Anteralign, Sovereign, Divergence, and Pivox interbody cages (Medtronic); Modulus cage (NuVasive); Infuse Bone Graft/rhBMP-2 (Medtronic) (Approved for this indication).

OBJECTIVE:Pedicle subtraction osteotomy (PSO) is a powerful technique for sagittal plane deformity correction. The authors aimed to investigate the differences in radiographic outcomes and rates of distal junctional problems (DJPs) between L3 and L4 PSOs. METHODS:Patients who underwent L3 or L4 PSO at a quaternary care center between 2005 and 2021 were retrospectively identified. DJPs were defined as either hardware failure or pseudarthrosis distal to the PSO level. RESULTS:In total, 116 patients were included: 86 (74.1%) underwent L3 PSO and 30 (25.9%) underwent L4 PSO. The mean imaging follow-up was 4.1 (range 1.0-10.9) years. There were no statistically significant differences in age, sex, BMI, operative time, and estimated blood loss. Preoperatively, there were no significant differences in mean sacral Hounsfield units and spinopelvic parameters, with the exception of pelvic incidence (PI; L3: 51.1° ± 11.2° vs L4: 57.9° ± 14.1°, p = 0.012) and the L1 pelvic angle (L3: 23.6° ± 10.1° vs L4: 34.8° ± 13.5°, p < 0.001). Postoperatively, there were no statistically significant differences in primary rod type, 2-rod versus multirod constructs, unilateral versus bilateral iliac fixation, number of levels fused, graft material, L5-S1 interbody fusion approach, and PI-lumbar lordosis mismatch. There were no significant differences between the cohorts in uni- versus bilateral pelvic fixation or type of fixation (iliac vs S2AI); however, patients who underwent L4 PSO had, on average, more pelvic screws placed (mean 1.9 ± 0.7 vs 1.5 ± 0.6, p = 0.002). L4 PSO resulted in larger postoperative L4-S1 segmental lordosis (37.2° ± 13.3° vs 21.4° ± 11.4°, p < 0.001) and reduced rates of postoperative low lordosis distribution index (20.0% vs 60.0%, p < 0.001). There were no significant differences in postoperative complication rates including CSF leak, iatrogenic dorsiflexion weakness, and 30- or 90-day readmissions. The L4 PSO cohort experienced lower DJP rates (6.7% vs 29.1%, p = 0.012), including hardware failure (3.3% vs 20.9%, p = 0.024) and pseudarthrosis (3.3% vs 25.6%, p = 0.008). Multivariate analysis found that multirod construct versus dual-rod configuration (OR 0.31, 95% CI 0.09-0.96) and L4 PSO (OR 0.18, 95% CI 0.02-0.80) were independently associated with decreased DJP rates. Age was also a risk factor for DJPs. The number of pelvic screws and pelvic screw fixation type did not predict DJPs. CONCLUSIONS:In addition to multirod configurations, L4 PSO resulted in a lower rate of DJPs compared with L3 PSO. This result might be due to a more physiological distribution of lumbar lordosis with L4 PSO.

BACKGROUND CONTEXT Cement augmentation (CA) has been used to enhance the stability of the construct in patients undergoing long spinal fusions for adult spinal deformities. However, cement leakage into segmental arteries may have detrimental effects on the blood supply of vertebral bodies, potentially increasing the risk of vertebral compression fractures and subsequent need for reoperation. PURPOSE Using a large national database, this study evaluated the impact of cement augmentation on reoperation rates following deformity fusion surgeries. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE N/A. OUTCOME MEASURES N/A. METHODS The PearlDiver-Mariner database was queried for patients undergoing deformity fusion between 2010 and 2021. Eligibility for inclusion was determined by age >18 years and CPT codes for deformity fusion (22800, 22802, 22804), pelvic fusion (22848), and presence or absence of vertebroplasty or kyphoplasty (22510-22515, 22520-22525). Reoperation greater than 90-days and complications within 90 days of surgery, including acute kidney injury, deep vein thrombosis, hematoma, foot drop, wound disruption and infection were compared between cohorts. Multivariable logistic regression adjusted for demographics and comorbidities including age, sex, diabetes, smoking and hypertension, was used to determine if outcomes differed significantly between cohorts with and without cement augmentation. RESULTS A total of 5,958 deformity fusion patients without cement augmentation and 261 patients with cement augmentation were included. Patients in the cement augmentation cohort were older (66.8±8.0 vs 58.2±17.0 years, p<0.001) and had higher proportions of female patients (78.9% vs 67.4%, p=0.0012). Rates of reoperation (31.4% vs 21.3%, p<0.001), pulmonary embolism (3.4% vs 1.4%, p=0.017), and urinary tract infection (13.8% vs 9.1%, p=0.016) were significantly greater in patients with cement augmentation than in those without. There was a significantly greater proportion of reoperation cases due to device reinsertion (17.1% vs 12.8%, p=0.036) in cases without cement augmentation. Multivariable logistic regression adjusted for baseline demographics and comorbidities demonstrated that cement augmentation was an independent and significant predictor of higher reoperation (OR 1.757, p<0.001), but not for pulmonary embolism (OR 1.857, p=0.0925) and urinary tract infection (OR 1.240, p=0.257). Differences in other outcomes including cardiac arrest, wound disruption, pneumonia, and nerve injury were not significant. CONCLUSIONS Cement augmentation in patients undergoing deformity fusion was associated with a significantly higher reoperation rate. Though cement augmentation may enhance the stability of the fusion construct, the greater risk for reoperation should be considered. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

This abstract reflects content previously published in the following source: Katz A, Hoang R, David W, Song J, Hoang T, Burch S. A113: Surgical delay predicts unplanned reoperation and increased length of stay following anterior fixation of odontoid fractures. Global Spine J. 2025 May 21;15(2 Suppl):4S–215S.https://pmc.ncbi.nlm.nih.gov/articles/PMC12099168/.

BACKGROUND CONTEXT Antepsoas lumbar interbody fusions (ATP) between L2/3 and L4/5 combined with a lateral anterior interbody fusion (ALIF) at L5/S1 offer a minimally invasive single position approach to reconstruct the anterior lumbar spine from L2-S1. There is limited data on patient reported outcomes and intra-operative complication rates comparing 1, 2, 3 and 4 level anterior reconstructions. PURPOSE The purpose of the study was to determine the complications, disposition and outcomes of one, two, three and four level reconstructions using a combination of an ATP and lateral ALIF approach to recontruct the anterior spine. STUDY DESIGN/SETTING Retrospective review of prospective nonrandomized clinical study of a single surgeon series. PATIENT SAMPLE A total of 318 patients undergoing 331 procedures with 638 instrumented levels were included with > 2 year follow up. OUTCOME MEASURES Outcome measures include VAS, ODI, EQ5D, surgical complications, blood loss and disposition. METHODS Patients undergoing one, two, three and four level reconstructions in the lateral position from L2-S1 were included in the study. VAS, ODI, EQ5D were collected pre- and postoperatively. EBL, surgical complications (infection, neural injury, vascular injury, durotomy, visceral injury, ureteric injury), re-operation, disposition and re-admissions were determined for the cohort. RESULTS There were 318 patients with mean age of 61.9 years undergoing a total of 638 levels that included: one level (n=147), two level (n=97), three level (n=51) and four level (n=36) fusions. The frequency of levels was as follows: L5/S1 (n=173), L4/5 (n=166), L3/4 (n=172), L2/3 (n=122). Mean EBL for 4 levels (232.67ml), 3 levels (126.96ml), 2 levels (100.82ml), 1 level (121.28ml) with no difference in EBL between levels fused (p>0.05). % patients had a vascular injury with a rate of 0.7%. No plexus injuries were identified. Revision anterior procedures occurred in 4.4% (n=14) with 1 revision on the same level (0.3%). No deep infections were identified. Significant difference was seen between anterior levels fused and disposition (p<0.05). VAS, EQ5D and ODI scores are displayed in Figures 1-3. CONCLUSIONS ATP and lateral L5/S1 ALIFs allow for single position surgery to be safely performed on multiple levels with no difference in complication rates or blood loss between one and four level fusion groups. It offers a unique surgical approach for multi-level reconstruction of the lumbar spine. FDA Device/Drug Status Clydesdale (Approved for this indication)

Background Assess correlation between preoperative cervical sagittal alignment (T1 slope [T1S] and C2-C7 cervical sagittal vertical axis [cSVA]) and postoperative cervical sagittal balance after posterior cervical laminoplasty. Methods Consecutive patients who underwent laminoplasty at a single institution with >6 weeks postoperative follow-up were divided into 4 groups based on preoperative cSVA and T1S (Group 1: cSVA <4 cm/T1S <20°; Group 2: cSVA ≥4 cm/T1S ≥20°; Group 3: cSVA <4 cm/T1S ≥20°; Group 4: cSVA <4 cm/T1S <20°). Radiographic analyses were conducted at 3 timepoints, and changes in cSVA, C2-C7 cervical lordosis (CL), and T1S -CL were compared. Results A total of 214 patients met inclusion criteria (28 patients had cSVA <4 cm/T1S <20° [Group 1]; 47 patients had cSVA ≥4 cm/T1S ≥20° [Group 2]; 139 patients had cSVA <4 cm/T1S ≥20° [Group 3]). No patients had cSVA ≥4 cm/T1S <20° (Group 4). Patients either had a C4-C6 (60.7%) or C3-C6 (39.3%) laminoplasty. Mean follow-up was 1.6 ± 1.32 years. For all patients, mean cSVA increased 6 mm postoperatively. cSVA significantly increased postoperatively for both groups with a preoperative cSVA <4 cm (ie, Groups 1 and 3 [P < 0.01]). For all patients, mean CL decreased 2° postoperatively. Groups 1 and 2 had significant differences in preoperative CL but nonsignificant differences at 6 weeks (P = 0.41) and last follow-up (P = 0.06). Conclusion Cervical laminoplasty resulted in a mean decrease in CL. Patients with high preoperative T1S, irrespective of cSVA, were at risk of loss of CL postoperatively. While patients with low preoperative T1S and cSVA <4 cm experienced a decrease in global sagittal cervical alignment, CL was not jeopardized. Clinical Relevance The results of this study may facilitate preoperative planning for patients undergoing posterior cervical laminoplasty. Level of Evidence 3.

Purpose To define the prevalence, characteristics, and treatment approach for proximal junction failure secondary to odontoid fractures in patients with prior C2-pelvis posterior instrumented fusions (PSF). Methods A single institution’s database was queried for multi-level fusions (6+ levels), including a cervical component. Posterior instrumentation from C2-pelvis and minimum 6-month follow-up was inclusion criteria. Patients who sustained dens fractures were identified; each fracture was subdivided based on Anderson & D’Alonzo and Grauer’s classifications. Comparisons between the groups were performed using Chi-square and T tests. Results 80 patients (71.3% female; average age 68.1 ± 8.1 years; 45.0% osteoporosis) were included. Average follow-up was 59.8 ± 42.7 months. Six patients (7.5%) suffered an odontoid fracture post-operatively. Cause of fracture in all patients was a mechanical fall. Average time to fracture was 23 ± 23.1 months. Average follow-up after initiation of fracture management was 5.84 ± 4 years (minimum 1 year). Three patients sustained type IIA fractures one of which had a concomitant unilateral C2 pars fracture. Three patients sustained comminuted type III fractures with concomitant unilateral C2 pars fractures. Initial treatment included operative care in 2 patients, and an attempt at non-operative care in 4. Non-operative care failed in 75% of patients who ultimately required revision with proximal extension. All patients with a concomitant pars fracture had failure of non-operative care. Patients with an intact pars were more stable, but 50% required revision for pain. Conclusions In this 11-year experience at a single institution, the prevalence of odontoid fractures above a C2-pelvis PSF was 7.5%. Fracture morphology varied, but 50% were complex, comminuted C2 body fractures with concomitant pars fractures. While nonoperative management may be suitable for type II fractures with simple patterns, more complex and unstable fractures likely benefit from upfront surgical intervention to prevent fracture displacement and neural compression. As all fractures occurred secondary to a mechanical fall, inpatient and community measures aimed to minimize risk and prevent mechanical falls would be beneficial in this high-risk group.

BACKGROUND CONTEXT Risk stratifying patients and predicting outcomes and complications has become increasingly important in spinal deformity surgery. A frailty phenotype based on strength, exhaustion and energy expenditure and weight loss may be a practical tool to predict a patient's overall outcome and complication rate following surgery. PURPOSE To determine if the frailty phenotype is a predictor of patient reported outcomes, complications and revision rates in adult spinal deformity (ASD) patients. STUDY DESIGN/SETTING Retrospective review of prospective cohort. PATIENT SAMPLE The frailty phenotype was determined on all new patients age ≥ 18 years. A total of 1,708 patients were prospectively enrolled over an 8-year period. Of these, 270 of these patients had a diagnosis of ASD with surgical intervention. OUTCOME MEASURES The frailty phenotype was used to predict VAS scores, EQ5D and Oswestry Disability Scores following surgical intervention along with complications and revision surgery. METHODS All new patients presenting to a tertiary spine clinic were asked to complete the Frailty Phenotype survey from 2014 to 2022. A preoperative frailty phenotype was calculated and patients were classified as robust, prefrail or frail based on previously reported methodology. We performed a retrospective review of prospective data of all patients with a frailty phenotype and then determined those within the cohort with a diagnosis of ASD and subsequent surgical intervention. Preoperative VAS, ODI and EQ5D scores were compared to data at 6 weeks, 3 months and 6 months along with early revision rates and complications at 2-year follow-up. RESULTS A total of 1,708 patients including 874 females were enrolled. Five hundred eighty-one, 671 and 456 patients were classified with mean age as robust (66.43 years SD 11.26), prefrail (66.45 years SD 12.01) and frail (66.87 years SD 10.72), respectively. Of the 1,708 patients, 270 underwent procedures to address ASD. This included 73 patients with robust frailty phenotypes, 105 prefrail patients and 92 frail patients. Frail patients had worse VAS back and leg, ODI and EQ5D scores preoperatively and at 6 months compared to Robust patients. Frail patients had a similar change in VAS, EQ5D and ODI scores following surgery at 6 months. No statistically significant difference in complication and revision rates were measured. All groups experienced significantly improved outcome scores at 6-month follow-up (p≤ 0.01). Each group experience significant improvement in Oswestry Disability Index (ODI) scores at the 6-month follow-up period (Frail preop 58 postop 43, Prefrail 53 postop 39, robust preop 45 postop 24, p<0.05). EQ5D scores similarly improved significantly in all groups from preoperative scores of 0.4, 0.52, and 0.58 to postoperative scores of 0.58, 0.68 and 0.77 in the frail, prefrail and robust groups, respectively (p 0.05). Mean blood loss for Frail and Robust patients were 1035.39 and 888.73, respectively p>0.05). No statistical difference in complication rates was identified. CONCLUSIONS In this cohort the frailty phenotype predicted pre- and postoperative back pain, leg pain, ODI and EQ5D scores in ASD surgery but not revisions or complications. Frailty phenotype is a simple and practical tool which can help prognosticate outcomes for patients undergoing surgery to address ASD and set expectations for surgeons. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs. Risk stratifying patients and predicting outcomes and complications has become increasingly important in spinal deformity surgery. A frailty phenotype based on strength, exhaustion and energy expenditure and weight loss may be a practical tool to predict a patient's overall outcome and complication rate following surgery. To determine if the frailty phenotype is a predictor of patient reported outcomes, complications and revision rates in adult spinal deformity (ASD) patients. Retrospective review of prospective cohort. The frailty phenotype was determined on all new patients age ≥ 18 years. A total of 1,708 patients were prospectively enrolled over an 8-year period. Of these, 270 of these patients had a diagnosis of ASD with surgical intervention. The frailty phenotype was used to predict VAS scores, EQ5D and Oswestry Disability Scores following surgical intervention along with complications and revision surgery. All new patients presenting to a tertiary spine clinic were asked to complete the Frailty Phenotype survey from 2014 to 2022. A preoperative frailty phenotype was calculated and patients were classified as robust, prefrail or frail based on previously reported methodology. We performed a retrospective review of prospective data of all patients with a frailty phenotype and then determined those within the cohort with a diagnosis of ASD and subsequent surgical intervention. Preoperative VAS, ODI and EQ5D scores were compared to data at 6 weeks, 3 months and 6 months along with early revision rates and complications at 2-year follow-up. A total of 1,708 patients including 874 females were enrolled. Five hundred eighty-one, 671 and 456 patients were classified with mean age as robust (66.43 years SD 11.26), prefrail (66.45 years SD 12.01) and frail (66.87 years SD 10.72), respectively. Of the 1,708 patients, 270 underwent procedures to address ASD. This included 73 patients with robust frailty phenotypes, 105 prefrail patients and 92 frail patients. Frail patients had worse VAS back and leg, ODI and EQ5D scores preoperatively and at 6 months compared to Robust patients. Frail patients had a similar change in VAS, EQ5D and ODI scores following surgery at 6 months. No statistically significant difference in complication and revision rates were measured. All groups experienced significantly improved outcome scores at 6-month follow-up (p≤ 0.01). Each group experience significant improvement in Oswestry Disability Index (ODI) scores at the 6-month follow-up period (Frail preop 58 postop 43, Prefrail 53 postop 39, robust preop 45 postop 24, p<0.05). EQ5D scores similarly improved significantly in all groups from preoperative scores of 0.4, 0.52, and 0.58 to postoperative scores of 0.58, 0.68 and 0.77 in the frail, prefrail and robust groups, respectively (p 0.05). Mean blood loss for Frail and Robust patients were 1035.39 and 888.73, respectively p>0.05). No statistical difference in complication rates was identified. In this cohort the frailty phenotype predicted pre- and postoperative back pain, leg pain, ODI and EQ5D scores in ASD surgery but not revisions or complications. Frailty phenotype is a simple and practical tool which can help prognosticate outcomes for patients undergoing surgery to address ASD and set expectations for surgeons.

Objective: To compare in-hospital and 30-day postoperative complications for lumbar spine operations with and without use of computer-assisted navigation. Methods: Patients who underwent 1-level to 3-level lumbar spinal instrumentation and fusions 2011 to 2014 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Emergent procedures and patients aged younger than 18 years were excluded. Patients whose surgery involved the use of computer-assisted navigation were propensity score matched 1:4 based on preoperative demographics and comorbidities to operations without the use of navigation. Multivariate analysis was done to compare postoperative complications. Results: In total, 8,500 patients (average age: 60.7 ± 12.9, male 3,866, female 4,634) were analyzed (1,700 navigation, 6,800 Non-Navigated). Operations with navigation had significantly fewer overall complications (24% vs. 27%, P = 0.008; odds ratio [OR] = 0.83; CI = 0.73 to 0.95), fewer minor complications (20% vs. 24%, P = 0.002; OR = 0.80; CI = 0.70 to 0.91), fewer blood transfusions (17% v. 20%, P = 0.013; OR = 0.82; CI = 0.71 to 0.95), more wound dehiscences (0.4% vs. 0.8%, P = 0.022; OR = 2.16; CI = 1.12,4.19), and shorter average lengths of hospital stays (4.8 ± 4.8 vs. 5.1 ± 5.8 days, P = 0.01). Operations with computer navigation had significantly longer average surgical times (247 ± 129 vs 221 ± 115 minutes, P < 0.001). No significant differences were observed in 30-day revision rates, readmissions, and mortality. Conclusion: Although use of computer-assisted navigation in short-segment lumbar spine fusions (1 to 3 levels) did not decrease revision rates for screw misplacement within 30 days postoperatively, it independently reduced the frequency of blood transfusions and minor complications and decreased hospital lengths of stay compared with operations without navigation. These benefits came at the expense of increased surgical times and wound dehiscences within 30 days postoperatively. Given the inherent limitations of large national databases, these results warrant confirmation through prospective, multicenter investigations.

OBJECTIVE:The aim of this study was to radiographically compare cage subsidence and displacement between L5-S1 lateral anterior lumbar interbody fusion (ALIF) cages secured with an anterior buttress plate and cages secured with integrated screws.METHODS:Consecutive patients who underwent L5-S1 lateral ALIF with supplemental posterior fixation by a single surgeon from June 2016 to January 2021 were reviewed. Radiographs were analyzed and compared between the two groups based on the type of fixation used to secure the L5-S1 lateral ALIF cage: 1) anterior buttress plate or 2) integrated screws. The following measurements at L5-S1 were analyzed on radiographs obtained preoperatively, before discharge, and at latest follow-up: 1) anterior disc height, 2) posterior disc height, and 3) segmental lordosis. Cage subsidence and anterior cage displacement were determined radiographically.RESULTS:One hundred thirty-nine patients (mean age 60.0 ± 14.3 years) were included for analysis. Sixty-eight patients were treated with an anterior buttress plate (mean follow-up 12 ± 5 months), and 71 were treated with integrated screws (mean follow-up 9 ± 3 months). Mean age, sex distribution, preoperative L5-S1 lordosis, preoperative L5-S1 anterior disc height, and preoperative L5-S1 posterior disc height were statistically similar between the two groups. After surgery, the segmental L5-S1 lordosis and L5-S1 anterior disc heights significantly improved for both groups, and each respective measurement was similar between the groups at final follow-up. Posterior disc heights significantly increased after surgery with integrated screws but not with the anterior buttress plate. As such, posterior disc heights were significantly greater at final follow-up for integrated screws. Compared with patients who received integrated screws, significantly more patients who received the anterior buttress plate had cage subsidence cranially through the L5 endplate (20.6% vs 2.8%, p < 0.01), cage subsidence caudally through the S1 endplate (27.9% vs 0%, p < 0.01), and anterior cage displacement (22.1% vs 0%, p < 0.01).CONCLUSIONS:In this radiographic analysis of 139 patients who underwent lateral L5-S1 ALIF supplemented by posterior fixation, L5-S1 cages secured with an anterior buttress plate demonstrated significantly higher rates of cage subsidence and anterior cage displacement compared with cages secured with integrated screws. While the more durable stability afforded by cages secured with integrated screws suggests that they may be a more viable fixation strategy for L5-S1 lateral ALIFs, there are multiple factors that can contribute to cage subsidence, and, thus, definitive presumption cannot be made that the findings of this study are directly related to the buttress plate.

Figure S1 shows an overview of the PDT fiber set-up and placement for a kyphoplasty case.

BACKGROUND CONTEXT: While osteoporosis is a risk factor for adverse outcomes in spinal fusion patients, diagnosing osteoporosis reliably in this population has been challenging due to degenerative changes and spinal deformities. Addressing that challenge, biomechanical computed tomography analysis (BCT) is a CT-based diagnostic test for osteoporosis that measures both bone mineral density and bone strength (using finite element analysis) at the spine; CT scans taken for spinal evaluation or previous care can be repurposed for the analysis. PURPOSE: Assess the effectiveness of BCT for preoperatively identifying spinal fusion patients with osteoporosis who are at high risk of reoperation or vertebral fracture. STUDY DESIGN: Observational cohort study in a multi-center integrated managed care system using existing data from patient medical records and imaging archives. PATIENT SAMPLE: We studied a randomly sampled subset of all adult patients who had any type of primary thoracic (T4 or below) or lumbar fusion between 2005 and 2018. For inclusion, patients with accessible study data needed a preop CT scan without intravenous contrast that con-tained images (before any instrumentation) of the upper instrumented vertebral level. OUTCOME MEASURES: Reoperation for any reason (primary outcome) or a newly documented vertebral fracture (secondary outcome) occurring up to 5 years after the primary surgery. METHODS: All study data were extracted using available coded information and CT scans from the medical records. BCT was performed at a centralized lab blinded to the clinical outcomes; patients could test positive for osteoporosis based on either low values of bone strength (vertebral strength <= 4,500 N women or 6,500 N men) and/or bone mineral density (vertebral trabecular bone mineral density <= 80 mg/cm3 both sexes). Cox proportional hazard ratios were adjusted by age, presence of obesity, and whether the fusion was long (four or more levels fused) or short (3 or fewer levels fused); Kaplan-Meier survival was compared by the log rank test. This project was funded by NIH (R44AR064613) and all physician co-authors and author 1 received salary support from their respective departments. Author 6 is employed by, and author 1 has equity in and consults for, the company that provides the BCT test; the other authors declare no conflicts of interest. RESULTS: For the 469 patients analyzed (298 women, 171 men), median follow-up time was 44.4 months, 11.1% had a reoperation (median time 14.5 months), and 7.7% had a vertebral fracture (median time 2.0 months). Overall, 25.8% of patients tested positive for osteoporosis and no patients under age 50 tested positive. Compared to patients without osteoporosis, those testing posi-tive were at almost five-fold higher risk for vertebral fracture (adjusted hazard ratio 4.7, 95% confi-dence interval = 2.2-9.7; p<.0001 Kaplan-Meier survival). Of those positive-testing patients, those who tested positive concurrently for low values of both bone strength and bone mineral den-sity (12.6% of patients overall) were at almost four-fold higher risk for reoperation (3.7, 1.9-7.2; Kaplan-Meier survival p<.0001); the remaining positive-testing patients (those who tested positive for low values of either bone strength or bone mineral density but not both) were not at significantly higher risk for reoperation (1.6, 0.7-3.7) but were for vertebral fracture (4.3, 1.9-10.2). For both clinical outcomes, risk remained high for patients who underwent short or long fusion. CONCLUSION: In a real-world clinical setting, BCT was effective in identifying primary spinal fusion patients aged 50 or older with osteoporosis who were at elevated risks of reoperation and vertebral fracture. (c) 2022 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Table S1 highlights the inclusion/exclusion criteria for the PDT clinical trial in table format.

OBJECTIVE:Generally, anterior lumbar interbody fusion (ALIF) was believed superior to transforaminal lumbar interbody fusion (TLIF) in induction of fusion. However, many studies have reported comparable results in lumbosacral fusion rate between the two approaches. This study aimed to evaluate the realistic lumbosacral arthrodesis rates following ALIF and TLIF in patients with degenerative spondylolisthesis as measured by CT and radiology. METHODS:Ninety-six patients who underwent single-level L5-S1 fusion through ALIF (n = 48) or TLIF (n = 48) for degenerative spondylolisthesis at the Spine Center, University of California San Francisco, between October 2014 and December 2017 were retrospectively evaluated. Fusion was independently evaluated and categorized as solid fusion, indeterminate fusion, or pseudarthroses by two radiologists using the modified Brantigan-Steffee-Fraser (mBSF) grade. Clinical data on sex, age, body mass index, Meyerding grade, smoking status, follow-up times, complications, and radiological parameters including disc height, disc angle, segmental lordosis, and overall lumbar lordosis were collected. The fusion results and clinical and radiographic data were statistically compared between the ALIF and TLIF groups by using t-test or chi-square test. RESULTS:The mean follow-up period was 37.5 (ranging from 24 to 51) months. Clear, solid radiographic fusions were higher in the ALIF group compared with the TLIF group at the last follow-up (75% vs 47.9%, p = 0.006). Indeterminate fusion occurred in 20.8% (10/48) of ALIF cases and in 43.8% (21/48) of TLIF cases (p = 0.028). Radiographic pseudarthrosis was not significantly different between the TLIF and ALIF groups (16.7% vs 8.3%; p = 0.677). In subgroup analysis of the patients without bone morphogenetic protein (BMP), the solid radiographic fusion rate was significantly higher in the ALIF group than that in the TLIF group (78.6% vs 45.5%; p = 0.037). There were no differences in sex, age, body mass index, Meyerding grade, smoking status, or follow-up time between the two groups (p > 0.05). The ALIF group had more improvement in disc height (7.8 mm vs 4.7 mm), disc angle (5.2° vs 1.5°), segmental lordosis (7.0° vs 2.5°), and overall lumbar lordosis (4.7° vs 0.7°) compared with the TLIF group (p < 0.05). Overall complication rates were similar between the TLIF and ALIF groups (10.4% vs 8.33%; p > 0.999). CONCLUSIONS:With a minimum 2-year radiographic analysis of arthrodesis at lumbosacral level by radiologists, the rate of solid radiographic fusions was higher in the ALIF group compared with the TLIF group, whereas the TLIF group had a higher rate of indeterminate fusion. Radiographic pseudarthrosis did not differ significantly between the TLIF and ALIF groups.

STUDY DESIGN:Operative video and supplemental manuscript.OBJECTIVE:To present a cement augmentation technique of the upper instrumented vertebra (UIV) and UIV+1 for prevention of proximal junctional fractures (PJFs) in multi-level thoracolumbar posterior instrumented fusions.SUMMARY OF BACKGROUND DATA:PJFs are unfortunately a common occurrence after multi-level thoracolumbar instrumented fusions to the pelvis for adult spinal deformity that can result in significant functional disability and often require costly revision operations. As such, their prevention is key.METHODS:A surgical video illustrates the nuances of a 2-level cement augmentation technique, consisting of an open vertebroplasty of the UIV through fenestrated screws and a muscle-sparing kyphoplasty of the UIV+1.RESULTS:Utility of performing an open vertebroplasty of the UIV through fenestrated screws and muscle-sparing kyphoplasty of the UIV+1 lies in its ability to minimize soft-tissue disruption at the adjacent segment while providing additional structural support to the anterior column at this high-risk zone.CONCLUSIONS:Cement augmentation of the UIV and UIV+1 consisting of a hybrid open vertebroplasty and muscle-sparing kyphoplasty can be an effective strategy to decrease the incidence of PJF after multi-level posterior thoracolumbar instrumented fusions to the pelvis for adult spinal deformity.

Study Design. Delphi method. Objective. To gain consensus on the following questions: (1) When should anticoagulation/antiplatelet (AC/AP) medication be stopped before elective spine surgery?; (2) When should AC/AP medication be restarted after elective spine surgery?; (3) When, how, and in whom should venous thromboembolism (VTE) chemoprophylaxis be started after elective spinal surgery? Summary of Background Data. VTE can lead to significant morbidity after adult spine surgery, yet postoperative VTE prophylaxis practices vary considerably. The management of preoperative AC/AP medication is similarly heterogeneous. Materials and Methods. Delphi method of consensus development consisting of three rounds (January 26, 2021, to June 21, 2021). Results. Twenty-one spine surgeons were invited, and 20 surgeons completed all rounds of questioning. Consensus (>70% agreement) was achieved in 26/27 items. Group consensus stated that preoperative Direct Oral Anticoagulants should be stopped two days before surgery, warfarin stopped five days before surgery, and all remaining AC/AP medication and aspirin should be stopped seven days before surgery. For restarting AC/AP medication postoperatively, consensus was achieved for low-risk/medium-risk/high-risk patients in 5/5 risk factors (VTE history/cardiac/ambulation status/anterior approach/operation). The low/medium/high thresholds were POD7/POD5/POD2, respectively. For VTE chemoprophylaxis, consensus was achieved for low-risk/medium-risk/high-risk patients in 12/13 risk factors (age/BMI/VTE history/cardiac/cancer/hormone therapy/operation/anterior approach/staged separate days/staged same days/operative time/transfusion). The one area that did not gain consensus was same-day staged surgery. The low-threshold/medium-threshold/high-threshold ranges were postoperative day 5 (POD5) or none/POD3-4/POD1-2, respectively. Additional VTE chemoprophylaxis considerations that gained consensus were POD1 defined as the morning after surgery regardless of operating finishing time, enoxaparin as the medication of choice, and standardized, rather than weight-based, dose given once per day. Conclusions. In the first known Delphi study to address anticoagulation/antiplatelet recommendations for elective spine surgery (preoperatively and postoperatively); our Delphi consensus recommendations from 20 spine surgeons achieved consensus on 26/27 items. These results will potentially help standardize the management of preoperative AC/AP medication and VTE chemoprophylaxis after adult elective spine surgery.

Introduction: Adjacent segment disease (ASD) of the cervical spine is a common disabling phenomenon that often requires surgical intervention. The goal of this study was to evaluate the economic impact of revision operations for cervical ASD. Methods: Consecutive adults who underwent revision cervical spine surgery for ASD at a single institution between 2014 and 2017 were retrospectively reviewed. Direct costs were identified from medical billing data and calculated for each revision surgery for ASD. Incomplete cost data for revision operations were used as a criterion for exclusion. Cost data were stratified based on the approach of the index and revision operations. Results: Eighty-five patients (average age 57 ± 10 years) underwent revisions for cervical ASD, which summed to $2 million (average $23,702). Revisions consisted of 45 anterior operations (anterior cervical diskectomy and fusion, 34; corpectomy, 10; and cervical disk arthroplasty, 1), 32 posterior operations (posterior cervical fusion, 14; foraminotomy, 14; and laminoplasty, 4), and 8 circumferential operations. Circumferential revisions had notably higher average direct costs ($57,376) than single approaches (anterior, $20,084 and posterior, $20,371). Of posterior revisions, foraminotomies had the lowest average direct costs ($5,389), whereas posterior cervical fusion had the highest average direct costs ($35,950). Of anterior revisions, corpectomies ($30,265) had notably greater average direct costs than anterior cervical diskectomy and fusion ($17,514). Costs were not notably different for revision approaches based on the index operations' approach. Discussion: Revision operations for cervical ASD are highly heterogeneous and associated with an average direct cost of $27,702. Over 3 years, revisions for 85 patients with cervical ASD represented a notable economic expense (greater than $2.0 million). Data availability: Deidentified data may be provided by request to the corresponding author.

Study Design: Cross-sectional observational. Background: The use of social media by providers can enhance patient education, complement offline information, facilitate patient support, stimulate brand building, and strengthen the organization’s market position. Risks of social media include, but are not limited to, a lack of quality, reliability, misrepresentation of credentials, influence of hidden and overt conflicts of interest, content that may jeopardize patient privacy, HIPAA regulations, and physicians’ credentials and licensure. Physicians’ use of social media may also expose him/her to lawsuits if providing specific medical advice on media platforms. Objective: To document the social media presence of a broad cohort of spine surgeons, and to discuss the benefits and risks of a social media presence. Methods: Cross-sectional observational of 325 Spine Surgeons from 76 institutions across the US. Description statistic and Pearson’s correlation were used to investigate the relationships between the variables. Results: Out of the 325 surgeons, 96% were male with an average age of 51.5 ± 10.7 years and 14.1 ± 9.6 years of experience. The frequency of social media use included 57.2% of surgeons had professional LinkedIn, 17.8% had professional Facebook, and less than 16% had other social media platforms. When combining all platforms together, 64.6% of all surgeons had at least one professional social media platform. 64.0% of these surgeons had no social media activity in the past 90 days, while 19.4% and 10.9% were active once and twice a month, respectively. Surgeon age (P = 0.004), years in practice (P < 0.001), and practice type (P < 0.001) were strongly correlated with social media activity. Conclusions: Given the scarcity of research on this topic and the novelty of the platforms, social media and online services continue to be utilized at a low level by spine surgeons. Issues regarding the risks of privacy issues with social media users continue to be a concern among medical professionals adopting this technology. This can largely be mitigated with the combination of physician education and informed consent from patients. The ability to connect with patients directly, and provide access to high-quality education and information will be of considerable benefit to our field well into the future.

BACKGROUND CONTEXT Although matching lumbar lordosis (LL) with pelvic incidence (PI) is an important surgical goal for adult spinal deformity (ASD), there is concern that overcorrection may lead to proximal junctional kyphosis (PJK). We introduce the upper instrumented vertebra – femoral angle (UIVFA) as a measure of appropriate postoperative position in the setting of lower thoracic to pelvis surgical correction for patients with sagittal imbalance. We hypothesize that a more posterior UIV position in relation to the center of the femoral head is associated with an increased risk of PJK given compensatory hyperkyphosis above the UIV. PURPOSE The purpose of this study is to evaluate if increased UIVFA is associated with PJK in operative management of ASD. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Adult patients undergoing lower thoracic (T9-T12) to pelvis correction of ASD with a minimum of two-year follow-up were included. OUTCOME MEASURES The primary outcome is PJK and proximal junctional failure (PJF). Methods In this retrospective cohort study, adult patients undergoing lower thoracic (T9-T12) to pelvis correction of ASD with a minimum of two-year follow-up were included. UIVFA was measured as the angle subtended by a line from the UIV centroid to the femoral head center to the vertical axis. UIV posterior to the femoral head center was positive (+) and UIV anterior the femoral head center was negative (-). A >10° kyphotic angle between the UIV and UIV+2 or a >10° increase from preop to postop were used to determine PJK. Patients with PJK that required revision surgery were defined as proximal junctional failure (PJF). Patients who developed PJK and those who did not were compared with preoperative and postoperative UIVFA, change between postoperative and preoperative UIVFA (deltaUIVFA), sagittal vertical axis (SVA), pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), lumbar lordosis (LL), pelvic incidence minus lumbar lordosis (PI-LL), thoracic kyphosis at T5-12 (TK) and the central sacral vertical line (CSVL). Results Of the 119 patients included in the study with an average 3.6-year follow-up, 51 (42.9%) had PJK and 24 (20.2%) had PJF. The average preoperative UIVFA was 7.0±0.7°, the average postoperative UIVFA 10.8±0.6°, and the average deltaUIVFA was 3.8±0.6°. Patients with PJK had significantly higher postoperative UIVFA (12.6±4.8° vs 9.4±6.6°, p=0.04), deltaUIVFA (6.1±7.6° vs 2.1±5.6°, p<0.01), postoperative PT (27.3±9.2 vs 23.3±11, p=0.04), postoperative lumbar lordosis (47.7±13.9° vs 42.4±13.1, p=0.04) and postoperative thoracic kyphosis (44.9±13.2 vs 31.6±18.8) than patients without PJK at two-year follow-up. With multivariate logistic regression, postoperative UIVFA and deltaUIVFA were found to be independent risk factors for PJK (p<0.05). DeltaUIVFA was found to be an independent risk factor for PJF (p<0.05). A receiver operating characteristic (ROC) curve for UIVFA as a predictor for PJK was established with an area under the curve of 0.67 (95% CI: 0.59-0.76). Per the Youden index, the optimal UIVFA cut-off value is 11.5°. Conclusions The more posterior the UIV is from the femoral head center after lower thoracic to pelvis surgical correction for ASD, the more patients are at risk for PJK. The greater the magnitude of posterior translation of the UIV from the femoral head center from preop to postop, the greater the likelihood for PJF. Further investigation into the consequences of sagittal overcorrection in the setting of ASD is warranted. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Although matching lumbar lordosis (LL) with pelvic incidence (PI) is an important surgical goal for adult spinal deformity (ASD), there is concern that overcorrection may lead to proximal junctional kyphosis (PJK). We introduce the upper instrumented vertebra – femoral angle (UIVFA) as a measure of appropriate postoperative position in the setting of lower thoracic to pelvis surgical correction for patients with sagittal imbalance. We hypothesize that a more posterior UIV position in relation to the center of the femoral head is associated with an increased risk of PJK given compensatory hyperkyphosis above the UIV. The purpose of this study is to evaluate if increased UIVFA is associated with PJK in operative management of ASD. Retrospective cohort study. Adult patients undergoing lower thoracic (T9-T12) to pelvis correction of ASD with a minimum of two-year follow-up were included. The primary outcome is PJK and proximal junctional failure (PJF). In this retrospective cohort study, adult patients undergoing lower thoracic (T9-T12) to pelvis correction of ASD with a minimum of two-year follow-up were included. UIVFA was measured as the angle subtended by a line from the UIV centroid to the femoral head center to the vertical axis. UIV posterior to the femoral head center was positive (+) and UIV anterior the femoral head center was negative (-). A >10° kyphotic angle between the UIV and UIV+2 or a >10° increase from preop to postop were used to determine PJK. Patients with PJK that required revision surgery were defined as proximal junctional failure (PJF). Patients who developed PJK and those who did not were compared with preoperative and postoperative UIVFA, change between postoperative and preoperative UIVFA (deltaUIVFA), sagittal vertical axis (SVA), pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), lumbar lordosis (LL), pelvic incidence minus lumbar lordosis (PI-LL), thoracic kyphosis at T5-12 (TK) and the central sacral vertical line (CSVL). Of the 119 patients included in the study with an average 3.6-year follow-up, 51 (42.9%) had PJK and 24 (20.2%) had PJF. The average preoperative UIVFA was 7.0±0.7°, the average postoperative UIVFA 10.8±0.6°, and the average deltaUIVFA was 3.8±0.6°. Patients with PJK had significantly higher postoperative UIVFA (12.6±4.8° vs 9.4±6.6°, p=0.04), deltaUIVFA (6.1±7.6° vs 2.1±5.6°, p<0.01), postoperative PT (27.3±9.2 vs 23.3±11, p=0.04), postoperative lumbar lordosis (47.7±13.9° vs 42.4±13.1, p=0.04) and postoperative thoracic kyphosis (44.9±13.2 vs 31.6±18.8) than patients without PJK at two-year follow-up. With multivariate logistic regression, postoperative UIVFA and deltaUIVFA were found to be independent risk factors for PJK (p<0.05). DeltaUIVFA was found to be an independent risk factor for PJF (p<0.05). A receiver operating characteristic (ROC) curve for UIVFA as a predictor for PJK was established with an area under the curve of 0.67 (95% CI: 0.59-0.76). Per the Youden index, the optimal UIVFA cut-off value is 11.5°. The more posterior the UIV is from the femoral head center after lower thoracic to pelvis surgical correction for ASD, the more patients are at risk for PJK. The greater the magnitude of posterior translation of the UIV from the femoral head center from preop to postop, the greater the likelihood for PJF. Further investigation into the consequences of sagittal overcorrection in the setting of ASD is warranted.