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Objective: To determine the effect of obesity on clinical, radiographic, and surgical outcomes after lateral lumbar interbody fusion (LLIF) versus minimally invasive surgery (MIS) transforaminal lumbar interbody fusion (TLIF) and compare the effectiveness of LLIF versus MIS TLIF in treating obese patients., Methods: A retrospective comparative analysis of patients who underwent single-level L4-5 LLIF or MIS TLIF over a 7-year period was performed. Spinopelvic parameters were compared based on preoperative and postoperative radiographs. Body mass index (BMI) ≥30 was deemed "high"; BMI <30 was deemed "low.", Results: In total, 154 patients underwent LLIF or MIS TLIF during the study period (33 TLIF high BMI, 45 TLIF low BMI, 28 LLIF high BMI, and 48 LLIF low BMI). Compared with TLIF high BMI patients, TLIF low BMI patients experienced superior posterior disc height restoration (P = 0.05), shorter operative duration (P = 0.01), decreased revision surgery rate (P = 0.02), reduced estimated blood loss (P = 0.04), and shorter hospital length of stay (P = 0.03). No differences in outcomes were seen in LLIF high BMI versus LLIF low BMI cohorts. Among obese patients, LLIF provided superior restoration in anterior disc height (P < 0.001), posterior disc height (P = 0.003), and neuroforaminal height (P = 0.002); shorter operative duration (P < 0.001); and decreased estimated blood loss (P = 0.008), compared with MIS TLIF., Conclusions: Obesity was associated with poorer overall radiographic and surgical outcomes after MIS TLIF but not LLIF. In obese patients in our cohort, LLIF provided superior improvements in spinopelvic parameters and surgical characteristics. BMI should be considered when deciding between LLIF and MIS TLIF., (Copyright © 2025 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Performing anterior lumbar interbody fusion (ALIF) in patients with a body mass index (BMI) >30 presents surgical challenges. To overcome those challenges, a modified procedure is described., Methods: This study retrospectively reviewed patients with a BMI >30 who underwent the modified L5-S1 ALIF procedure from August 2017 to September 2023. Patient demographic and operative characteristics were collected. Clinical and radiographic outcomes were analyzed before surgery and at 1-year follow-up. An analysis was performed comparing patients with a BMI >30 who underwent the modified ALIF procedure versus the standard ALIF procedure., Results: A total of 26 patients with BMI >30 were evaluated. Thirteen received treatment with the modified ALIF technique, and 13 received treatment with the standard ALIF technique. Operative time was significantly shorter in the modified ALIF technique cohort (P = 0.006). Preoperative and postoperative radiographic findings indicated significant differences in anterior disc height (P < 0.001), posterior disc height (P = 0.02), and L5-S1 segmental lordosis (P < 0.001) in patients undergoing the modified ALIF technique. There were no intraoperative complications. Postoperative visual analog scale for back pain, visual analog scale for leg pain, and Oswestry Disability Index scores significantly improved after surgery (P < 0.05) in both cohorts after 1 year. Complete interbody fusion was achieved according to computed tomography evaluation 1 year after surgery in more than 80% of cases., Conclusions: ALIF surgery is a safe technique to address lumbar pathologies. This operative technique provides complimentary abdominal exposure data for access surgeons while performing ALIFs in patients with BMI >30. This technique could reduce operative time in such patients., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: To investigate associations between preoperative lumbar multifidus muscle (LMM) and psoas major muscle qualities and preoperative and postoperative patient-reported outcomes (PROs) after anterolateral lumbar interbody fusion (A-LLIF)., Methods: A retrospective review was conducted of patients with A-LLIF between L1 and S1 during 2017-2022 at a single institution who had at least approximately 1 year of follow-up and preoperative magnetic resonance imaging available. Preoperative magnetic resonance imaging was analyzed using 2 image analysis platforms (AMBRA and ImageJ). Parameters studied included cross-sectional area (CSA) and fat infiltration indices. Pearson correlation and multiple linear regression analyses were used to study relationships between muscle quality and preoperative and postoperative PROs. Subanalyses were performed for LMM CSA percentiles and stratification of previous surgery., Results: One hundred patients met the inclusion criteria (mean [standard deviation] age, 65.3 [11.0] years; 57% women, 43% men) during a mean (standard deviation) follow-up period of 1.29 (0.20) years. In total, 207 surgical levels were analyzed. Smaller LMM CSA was significantly associated with greater preoperative disability and preoperative back pain (P < 0.04 [ImageJ]). There were no statistically significant confounding factors. Patients with greater LMM CSA and previous lumbar procedures (n = 42) had more improvement in visual analog scale for lower back pain delta scores (P = 0.02 [ImageJ]; P = 0.04 [AMBRA]). Neither LMM fat infiltration indices nor psoas major muscle morphology influenced PROs., Conclusions: Significant associations were found between LMM CSA and preoperative disability and back pain. Compared to A-LLIF patients with larger LMM (CSA >12 cm 2 ), those with LMM CSA <5 cm 2 had significantly greater preoperative disability and back pain., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: Anterior lumbar interbody fusion (ALIF) can be combined with posterior column osteotomies (PCOs) to maximize lordotic correction. This study compares radiographic changes in regional and segmental lordosis in patients undergoing ALIF with and without PCOs., Methods: Patients >18 years old who underwent ALIF at 1 or 2 segments at a single institution (January 2014-July 2020) were included. Preoperative and postoperative radiographic parameters were determined, and a propensity-matched analysis was performed., Results: Ninety-nine patients (53 [54%] men) underwent ALIF at 129 levels (mean [SD], 1.3 [0.46] levels; median [range] age, 61 [32-83] years). PCOs were performed in 13 (13%) patients at 19 (15%) segments. PCOs included 13 Schwab grade 1 and 6 grade 2 osteotomies. All measures, including lumbar lordosis, segmental lordosis, disc angle, and neural foramen height, increased significantly after surgery (P ≤ 0.003). In the propensity-matched analysis, PCO was associated with greater increases in lumbar lordosis (14.9° vs. 8.2°, P = 0.02), segmental lordosis (14.0° vs. 9.6°, P = 0.03), and disc angle (15.0° vs. 10.2°, P = 0.046). The change in disc angle more closely approximated the inherent lordosis of the cage when PCO was performed (94% vs. 62%, P = 0.004)., Conclusions: Performing PCOs and ALIFs significantly increased the radiographic correction of overall and segmental lordosis in the selected patient cohort. The disc angle achieved with ALIF without PCOs was approximately 60% of the cage lordosis. The addition of PCO allowed for greater segmental compression, enabling the disc angle to reach nearly 100% of the inherent interbody cage lordosis., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Surgical management of lumbar spondylolisthesis requires neural decompression, stabilization, and alignment restoration. Minimally invasive spine approaches offer a wide variety of advantages for spondylolisthesis management. This intraoperative note describes the treatment of L4-L5 lumbar spondylolisthesis with lateral lumbar interbody fusion (LLIF) and percutaneous pedicle screw fixation (PSF)., Methods: The surgical technique for treating L4-L5 lumbar spondylolisthesis using a minimally invasive approach with LLIF and percutaneous PSF is described. This operative technique is illustrated with figures, and an intraoperative case example of its application is described., Results: LLIF with percutaneous PSF can be a safe, effective, and reliable option for treating lumbar spondylolisthesis when applied with appropriate surgical technique in a selected patient population. This technique is a valuable addition to the range of available spine surgical options., Conclusions: LLIF with percutaneous PSF can be an effective technique for treating lumbar L4-L5 spondylolisthesis., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: Degenerative diseases of the lumbar spine decrease lumbar lordosis (LL). Anterior lumbar interbody fusion (ALIF) at the L5-S1 disc space improves segmental lordosis, LL, and sagittal balance. This study investigated reciprocal changes in spinopelvic alignment after L5-S1 ALIF., Methods: A retrospective chart review identified patients who underwent L5-S1 ALIF with or without posterior fixation at a single institution (November 1, 2016 to October 1, 2021). Changes in pelvic tilt, sacral slope, proximal LL (L1-L4), distal LL (L4-S1), total LL (L1-S1), segmental lordosis, pelvic incidence-LL mismatch, thoracic kyphosis, cervical lordosis, and sagittal vertical axis were measured on preoperative and postoperative radiographs., Results: Forty-eight patients were identified. Immediate postoperative radiographs were obtained at a mean (SD) of 17 (20) days after surgery; delayed radiographs were obtained 184 (82) days after surgery. After surgery, patients had significantly decreased pelvic tilt (15.71° [7.25°] vs. 17.52° [7.67°], P = 0.003) and proximal LL (11.86° [10.67°] vs. 16.03° [10.45°], P < 0.001) and increased sacral slope (39.49° [9.27°] vs. 36.31° [10.39°], P < 0.001), LL (55.35° [13.15°] vs. 51.63° [13.38°], P = 0.001), and distal LL (43.17° [9.33°] vs. 35.80° [8.02°], P < 0.001). Segmental lordosis increased significantly at L5-S1 and decreased significantly at L2-3, L3-4, and L4-5. Lordosis distribution index increased from 72.55 (19.53) to 81.38 (22.83) (P < 0.001)., Conclusions: L5-S1 ALIF was associated with increased L5-S1 segmental lordosis accompanied by pelvic anteversion and a reciprocal decrease in proximal LL. These changes may represent a reversal of compensatory mechanisms, suggesting an overall relaxation of spinopelvic alignment after L5-S1 ALIF., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Osseous spinal metastases from intracranial meningiomas are rare but represent a serious disease progression. A literature review was performed on this topic to understand the clinical course of patients with this disease entity. We also present a case of spinal metastasis in a patient with a World Health Organization grade III meningioma., Methods: The PubMed/MEDLINE database was queried on August 15, 2021, using the keywords (meningioma) AND (metastasis) AND (vertebra∗ OR spin∗). All publications reporting outcomes of patients with meningioma metastatic to the spine were included. Disease characteristics, treatment modality, and outcomes were extracted from each study. Because data availability varied widely between studies, no meta-analysis was performed., Results: A total of 30 articles with 33 cases were included. Outcome data varied greatly in terms of quality and length of follow-up. Of 28 cases with reported outcomes data, 20 resulted in patient mortality ranging from a few weeks to 5 years after spinal metastasis. Mean (standard deviation) survival time was 5.8 (6.4) years following initial diagnosis, but only 1.4 (3.2) years from spinal metastasis. The longest survivor was noted to have no recurrence of disease 4 years after spinal metastasis., Conclusions: Bony spinal metastasis from intracranial meningioma is an extremely rare occurrence. Within the limits of the available literature, outcomes of patients with this disease appear to be poor. However, data reporting is inconsistent, and several articles did not report any outcome data. Further study is needed to better clarify the course and prognosis of this disease., (Copyright © 2023. Published by Elsevier Inc.)

Background: Adjacent level degeneration is a precursor to construct failure in adult spinal deformity surgery, but whether construct design affects adjacent level degeneration risk remains unclear. Here we present a biomechanical profile of common deformity correction constructs and assess adjacent level biomechanics., Methods: Standard nondestructive flexibility tests (7.5 Nm) were performed on 21 cadaveric specimens: 14 pedicle subtraction osteotomies (PSOs) and 7 anterior column realignment (ACR) constructs. The ranges of motion (ROM) at the adjacent free level in flexion, extension, axial rotation, and lateral bending were measured and analyzed., Results: ACR constructs had a lower ROM change on flexion at the proximal adjacent free level than constructs with PSO (1.02 vs. 1.32, normalized to the intact specimen, P < 0.01). Lateral lumbar interbody fusion adjacent to PSO and 4 rods limits ROM at the free level more effectively than transforaminal interbody fusion and 2 rods in correction constructs with PSO. Use of 2 screws to anchor the ACR interbody further decreased ROM at the proximal adjacent free level on flexion, but adding 4 rods in this setting added no further limitation to adjacent segment motion., Conclusions: ACR constructs have less ROM change at the adjacent level compared to PSO constructs. Among constructs with ACR, anchoring the ACR interbody with 2 screws reduces motion at the proximal adjacent free level. When PSOs are used, lateral lumbar interbody fusion adjacent to the PSO level has a greater reduction in adjacent-segment motion than transforaminal interbody fusion, suggesting that deformity construct configuration influences proximal adjacent-segment biomechanics., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: To compare biomechanical stability and rod strain among uniform rod (UR), tapered rod (TR), and UR+accessory rod (AR) constructs in a human cadaveric C7 pedicle subtraction osteotomy (PSO) model of cervical deformity correction., Methods: Fourteen human cadaveric C2-T4 specimens were divided into 2 statistically equivalent groups. Specimens were instrumented from C2 to T3, and a 25° PSO was performed at C7. Group 1 was instrumented with 3.5-mm to 5.5-mm titanium TRs, and group 2 received 4.0-mm titanium URs. The UR group was also tested with lateral 4.0-mm titanium ARs (UR+AR) at C5-T2. All conditions were tested with 2.0 Nm pure moment and 70 N compressive load. Intervertebral range of motion (ROM) and posterior rod strain (pRS) were measured at C2-C3, T2-T3, and the PSO level. Statistical comparisons used 1-way analysis of variance., Results: ROM was significantly reduced in the TR versus UR construct for right axial rotation (P = 0.04) at the PSO level; ROM with TR was significantly greater than with UR and UR+AR in compression (P ≤ 0.02). At the PSO level, pRS was significantly greater in TR than in UR+AR in flexion, extension, and right axial rotation (P ≤ 0.02). At T2/3, pRS was higher in UR than TR in left axial rotation (P = 0.003)., Conclusions: C7 PSO is highly destabilizing. Maximal rod strain was concentrated across the PSO and the cranial fixation site. TR provided higher stability than did UR in 1 direction of movement; however, UR+AR provided the greatest reduction of pRS., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: Single-position surgery in prone position is a novel technique for lateral interbody fusion with pedicle screw fixation. We performed a radiographic comparison of patients treated for spondylolisthesis using the prone lateral (PL) transpsoas approach versus the traditional dual position (DP) approach (lateral decubitus then prone)., Methods: Thirty consecutive patients with spondylolisthesis were treated using the PL approach (n = 15) versus the dual position approach (n = 15). Radiographic factors in the groups were retrospectively compared., Results: The groups were similar for age, sex, body mass index, and implant size, but there were more 15° (vs. 10°) cages inserted in the dual position group. Radiographically the groups had similar baseline spinopelvic parameters, lumbar lordosis (LL), segmental lordosis, anterolisthesis, and disc height (P > 0.05). Postoperatively the PL group demonstrated a larger improvement in segmental lordosis (5.1° vs. 2.5°, P = 0.02), but not overall LL (6.3° vs. 3.1°, P = 0.14). Both groups had similar improvements in pelvic tilt, disc height, and spondylolisthesis reduction (P > 0.05). The mean relative distance of the implant from the posterior edge of the vertebral body was greater in the PL group (26% vs. 17%, P < 0.001) indicating a tendency for more anterior cage placement. However, there was no significant correlation between the relative cage position and the increase in segmental lordosis (P = 0.35), so this result alone did not explain the relative increase in lordosis seen., Conclusions: This is the first study to our knowledge to demonstrate an improvement in segmental lordosis for patients with single-level spondylolisthesis using the PL approach., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: We sought to evaluate dynamic balance and postural stability in patients with adult spinal deformity (ASD) compared with published age-matched normative data., Methods: Eleven patients with ASD were prospectively enrolled. Postural stability was tested using static and dynamic posturography; patients stood on a movable platform with an integrated force plate and performed standardized sensory organization testing (SOT), evaluating the influence of sensory processing on postural stability under 6 conditions, and motor control testing, assessing reflexive postural reactions to an external perturbation. Patient performance was compared with that of published age-matched controls. Quality of life metrics included scores on the Scoliosis Research Society-22 questionnaire, SF-36, and Morse Fall Scale. Correlations between postural stability and radiographic measurements were performed., Results: ASD patients demonstrated significantly lower SOT scores (P ≤ 0.03) in 5 of 6 conditions tested and greater latency of limb movement during backward translation (P = 0.04) compared with controls. Lower SOT scores were associated with a history of falls. ASD patients who self-reported falling in the previous 6 months, when compared with nonfallers, demonstrated significantly lower SOT scores (P = 0.04) and significantly lower Scoliosis Research Society-22 self-image subscores (P = 0.003). Thoracic kyphosis and mediolateral sway (predictor of falls) were positively correlated in the eyes-open and eyes-closed conditions (P ≤ 0.04)., Conclusions: ASD patients demonstrated impaired postural stability, diminished sensory integration, and delayed response to external perturbations compared with normal control data. Postural stability and quality of life metrics correlated with self-reported falls. These findings suggest that ASD patients have abnormal postural stability and may be at elevated risk of falls., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Anterior column realignment (ACR) was developed as a minimally invasive method for treating sagittal imbalance. However, rod fracture (RF) rates associated with ACR are not known. Our objective was to assess the rate of and risk factors for RF following ACR in deformity correction surgery., Methods: We conducted a retrospective multicenter review of patients with adult spinal deformity (ASD) who underwent ACR for deformity correction. ASD was defined as coronal Cobb angle ≥20°, pelvic incidence-lumbar lordosis >10°, sagittal vertical axis ≥5 cm, pelvic tilt ≥25°, or thoracic kyphosis ≥60°. Inclusion criteria were ASD, age >18 years, use of ACR, and development of RF or full radiographs obtained at least 1 year after surgery that did not demonstrate RF., Results: Ninety patients were identified, with mean follow-up of 2.3 ± 1.4 years (age, 64.1 ± 9.4; 54 [60%] women). The most common ACR location was L3/4 (42 cases; 47%). Mean fusion length was 7.5 ± 3.6 levels. Four (4.4%) of 90 patients developed RF within 12 months of surgery. RF occurred adjacent to ACR in all cases; RF was not associated with focal correction (P = 0.49), rod material (P = 0.8), degree of correction (P > 0.07), or interbody at L5/S1 (P = 0.06). RF was associated with longer fusion constructs in univariate (P = 0.002) and multivariate (P = 0.03) analyses., Conclusions: RF occurred in 4.4% of patients with ASD who underwent ACR with a minimum of 1-year follow-up. RF was not associated with focal correction but appears to be associated with global correction and extent of fixation., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: An increasing body of literature describing use of high-fidelity surgical training models is challenging long-held dogma that cadavers provide the best medium for postgraduate surgical skills training. The purpose of this study was to describe a surgical skills course comprising entirely synthetic training models developed by resident and attending neurosurgeons and to evaluate their perceptions of the overall usefulness of this course and its usefulness compared with cadaveric courses., Methods: Ten high-fidelity neurosurgical training models were developed. A neurosurgical skills course for residents was structured to include 7 spinal and 3 cranial learning stations, each with its own model and assigned attending expert. Resident and attending neurosurgeons were asked to complete surveys on their overall impressions of the course and models and on workload comparisons between models and real cases. Student t tests were used for statistical comparisons., Results: Survey responses were collected from 9 of 16 participating residents (56.3%) and 3 of 10 attending neurosurgeons (30.0%). Both groups believed that the course was very helpful overall to resident education. Respondents furthermore believed that the course was more helpful overall than cadaveric courses. Task load index testing showed no significant workload difference between models and real cases (P ≥ 0.17), except in temporal demand (P < 0.001)., Conclusions: Resident and attending neurosurgeons subjectively believe that high-fidelity synthetic models were superior to cadavers as a surgical skills teaching platform. This study raises the question of whether cadavers should remain the gold standard for surgical skills courses. Expanded use of these teaching models and further study are warranted., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Sagittal imbalance in adult spinal deformity (ASD) likely influences balance and ambulatory capacity because of muscular demand, pain, and disability. Disability measures for ASD rely heavily on ambulatory function; however, current metrics may fail to fully capture its contribution. We sought 1) to determine the utility of continuous remote step count monitoring and activity tracking in ASD using a consumer-friendly accelerometer, and 2) to investigate trends and patterns both before and after surgical intervention., Case Description: One patient with progressive ASD was enrolled. Daily step count (SC), distance traveled (DT), and levels of activity were measured using a wrist-mounted device for 17 months. Spinopelvic parameters were measured from standing radiographs. The patient underwent T4-ilium long-segment fusion for correction of progressive deformity (coronal cobb angle: 8°; sagittal vertical axis: 4 cm; coronal vertical axis: 2 cm); recovery was uneventful. The device was worn for 216 of 520 (41%) recorded days during waking hours, with an average SC of 5254 ± 2696 per day. SC (P < 0.001), DT (P < 0.001), and minutes of light activity (LA) (P < 0.001) declined over the 9-month preoperative course, whereas sedentary activity increased (P < 0.001). After surgery, SC, DT, and LA decreased in the early postoperative period, with a significant increase at 7-8 months compared with the preoperative period (P < 0.001)., Conclusions: Wrist-mounted devices are a noninvasive and effective measure to track daily activity and ambulatory capacity of patients with spinal deformity. In a single case, progressive deformity correlated with worsening activity levels, whereas deformity correction improved SC and activity level. These results support remote activity monitoring as an exploratory outcome for future studies., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: A comparative evaluation of operative costs between single-level transforaminal interbody fusion (TLIF) and stand-alone lateral transpsoas interbody fusion (LIF) has not yet been done. We analyzed the costs, operative parameters, and early outcomes of single-level stand-alone LIF versus single-level TLIF., Methods: Ten patients who underwent single-level TLIF and 10 patients who underwent single-level stand-alone LIF were included in the analysis. Total, variable, and fixed costs from perioperative data were available from a single institution. In addition, patient demographics, length of hospital stay, and 30-day outcomes and readmission rates were reviewed., Results: Total cost, variable cost, and fixed costs were significantly lower in the LIF group, and there was no difference in outcomes., Conclusions: Single-level stand-alone LIF may prove to be more cost-effective and provide cost savings with analogous 30-day outcomes compared with single-level TLIF procedures., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Traditional open approaches to correct lumbar spine deformities include 3-column osteotomies, such as a pedicle subtraction osteotomy (PSO). Minimally invasive surgical (MIS) techniques have been developed for lateral transpsoas anterior column realignment (ACR). These 2 techniques have not previously been combined. Our objective was to investigate the cadaveric feasibility of a combined hybrid MIS ACR-PSO technique for deformity correction and to review early clinical experience., Methods: The feasibility of the combined ACR-PSO technique was evaluated in 4 fresh cadaveric specimens. The operative experience, complications, and early clinical outcomes in patients treated with the combined approach to correct global sagittal imbalance were reviewed., Results: In the cadaveric study, the combined ACR-PSO resulted in a mean 46.0° increase in lordosis (P < 0.001). Nine patients treated with ACR-PSO were evaluated (mean age, 65.2 years; 33.3% female). Most patients (6/9; 66.7%) underwent ACR at L1/2 or L3/4; 8 (88.8%) had PSO at L3 or L4. On average, 10.6 ± 3.8 levels were fused. Significant decreases in mean pelvic tilt (P = 0.01), spinopelvic mismatch (P < 0.001), and T1 spinopelvic inclination (P = 0.03) were observed postoperatively; mean lumbar lordosis (P = 0.007), intradiscal angle (P = 0.001), and thoracic kyphosis (P = 0.04) significantly increased. The overall complication rate was 55.6% (5/9)., Conclusions: Our early experience suggests that a combined ACR-PSO with posterior fixation allows for significant correction of segmental lordosis and global imbalance. This combined approach may maximize results attainable with hybrid MIS-open surgical techniques and represents a complementary option to PSO and other posterior approaches., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Vascularized bone grafts (VBGs) are described as having superior osteogenicity, osteoconductivity, and osteoinductivity compared with other graft types and have been used in high-risk patients to augment arthrodesis. Pedicled VBGs are rotated on an intact vascular pedicle and therefore maintain all the benefits of VBGs but avoid many of the challenges and additional morbidity of free-tissue transfer. This study describes a novel surgical technique for rotating vascularized spinous process into the posterolateral space for augmenting arthrodesis in patients undergoing posterolateral fusion (PLF)., Methods: A technique is described for rotating the spinous process into the posterolateral space on an intact vascular pedicle of paraspinal muscle. Early clinical and radiographic outcomes are reported for 4 patients who have undergone this procedure., Results: Four patients were treated with a single or 2-level PLF combined with posterior, anterior, or lateral interbody fusion and vascularized spinous process graft. Three-month postoperative computed tomography scans demonstrated a dislodged graft in 1 patient and successful arthrodesis in 3 patients. Additional operative time taken for graft harvest and implantation ranged from 22 minutes for the first patient to 6 minutes for the fourth patient., Conclusions: Rotation of vascularized spinous process graft for augmentation of posterolateral arthrodesis in the lumbar spine is a potentially safe, effective surgical technique that results in successful arthrodesis in as little as 3 months but requires further study. This technique is expected to add little additional time or morbidity to the traditional lumbar PLF because it requires no separate incision or additional bone removal., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: Anterior column realignment (ACR) is a minimally invasive surgical technique used for the correction of adult sagittal plane deformity. ACR is performed via a minimally invasive lateral transpsoas approach with anterior longitudinal ligament release and hyperlordotic cage placement. The objective of this study was to compare radiographic outcomes and complications in patients treated by ACR or Pedicle subtraction osteotomy (PSO)., Methods: Patients who underwent ACR were matched with patients from a retrospective PSO dataset, by pelvic incidence, lumbar lordosis, and thoracic kyphosis. Inclusion criteria included pelvic incidence and lumbar lordosis mismatch > 10°, pelvic tilt > 25°, and/or C7 sagittal vertical axis >5 cm, and minimum 1-year follow-up., Results: All (n = 17) patients who underwent ACR underwent second-stage open posterior instrumented fusion. There were no differences in baseline demographic or radiographic parameters. Both groups were found to have significant improvement from preoperative to final follow-up for lumbar lordosis, T1 spinopelvic inclination, and T1 pelvic angle. Pelvic tilt did not improve with PSO (31° to 28°) at final follow-up but did improve in ACR group (34° to 25°). No differences were identified at 3-month or final follow-up for lumbar lordosis (51° vs. 47°), pelvic tilt (25° vs. 28°), and T1 pelvic angle (23° vs. 24°). The group undergoing PSO achieved greater T1 spinopelvic inclination correction (8° vs. 1.9°). Patients who underwent ACR had significantly less estimated blood loss than patients who underwent PSO (1.6 vs. 3.6 L, respectively), but no difference in the overall major complication rates was found (35.3% vs. 41.2%, respectively)., Conclusions: ACR achieved similar radiographic results as PSO in a matched cohort with significantly less estimated blood loss and similar overall complication rate., (Copyright © 2017. Published by Elsevier Inc.)

Background: The second part of this study reanalyzes Ponce and Lozano's (2010) list of classics to create a new list of "foundational" articles in neurosurgery. Ponce and Lozano (2010) previously published a list of 106 neurosurgery classics, as defined by Garfield and his 400 citation criterion., Methods: We used the Web of Science citation reports to create graphs for each study showing the total citations it received as a function of time. Each graph was subjectively analyzed independently and scored as "foundational" or "classic only," based on whether the trend of citations received per year was uptrending, neutral, or downtrending., Results: Of the 101 evaluated classics, 53 qualified as foundational. Over half of these studies were published in Journal of Neurosurgery (13), New England Journal of Medicine (12), or Lancet (5). Grading systems, randomized trials, and prospective studies were most likely to achieve foundational status. Only 30% of functional and 17% of endovascular classics qualified as foundational (compared with 100% of spine classics), suggesting that these fields are rapidly changing or less mature subspecialties still developing a foundational literature base., Conclusion: By assessing citation counts as a function of time, we are able to differentiate classic neurosurgical studies that are critical to modern-day practice from those that are primarily of historic interest. Given the exponential growth of literature in our field, analyses such as these will become increasingly important to both trainees and senior neurosurgeons who strive to educate themselves on the data that drive modern-day clinical decision making., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Introduction: Adult spinal deformity (ASD) surgery carries the risk of spinal cord injury. Spinal cord ischemia is often implicated in the pathogenesis but has not been directly investigated. Here we present our index case as a proof of concept for a study evaluating the role of spinal cord perfusion (SCP) changes in ASD correction., Methods: ASD surgery was performed in the usual fashion with the addition of 1) SCP monitoring, using laser Doppler probe fixated to the dura at the level of the pedicle subtraction osteotomy (PSO) and 2) intrathecal pressure monitoring, using a lumbar drain. Somatosensory evoked potential (SSEP) and motor evoked potential (MEP) were monitored throughout the case., Results: An 84-year-old male with kyphoscoliosis and progressive myelopathy causing diminished motor and sensory function was treated with T4 PSO and long segment reconstruction. At baseline, SSEP signals were detectable in all 4 extremities, MEP signals were present in the right foot only, intrathecal pressure was 4 mm Hg, and mean SCP was 21.2 perfusion units. The osteotomy was performed and reduced in 2 steps. After the first step of reduction, MEP signals appeared in the left leg and increased in amplitude in the right leg, and SCP simultaneously increased to 205.6. Further reduction led to MEP signal loss in both legs and decrease in SCP to 39.2. With partial reversal of the reduction, MEP signals returned in both legs and SCP improved to 76.0. Final reduction maneuvers were then performed in a delayed fashion before closure, with stable MEP signals and a final SCP of 42.9. SSEP signals, vital signs, and intrathecal pressure were stable throughout the case. Postoperatively the patient was neurologically stable., Conclusions: The present case provides the first direct evidence that fluctuations in SCP may contribute to neurologic changes during ASD surgery. Further investigation is under way to further elucidate the underlying mechanisms, with the ultimate goal of developing targeted strategies for spinal cord protection during these high-risk cases., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: Subarachnoid hemorrhage (SAH) has a worldwide incidence of approximately 10.5 cases per 100,000 person-years and constitutes 3% of all strokes. Erythropoietin (EPO) has recently been proposed for the treatment of a variety of brain diseases, including SAH, because of its neuroprotective effects. Hence, the current evidence in the published literature was reviewed to determine the potential utility of EPO in the treatment of SAH., Methods: A careful retrospective review of the literature was performed to determine the potential benefit of employing EPO in the treatment of SAH and its sequelae., Results: Careful literature review revelaed that the use of EPO may not necessarily reduce the incidence of vasospasm after SAH, but it may reduce the severity and its eventual outcome., Conclusion: Given the recent trial results, a dose-escalation study and subsequent randomized trial should be considered., (Copyright © 2010 Elsevier Inc. All rights reserved.)

L-type Ca(2+) channel activity was assayed in L6 cells as the rate of nifedipine-sensitive Ba(2+) influx in a depolarizing medium. In the absence of extracellular Ca(2+), activation of protein kinase C (PKC) with phorbol-12-myristate-13-acetate (PMA) or thymeleatoxin (TMX) inhibited Ba(2+) influx by 38%. Thapsigargin (Tg), a selective inhibitor of the Ca(2+)-ATPase in the sarcoplasmic reticulum, evoked a rise in the cytosolic Ca(2+) concentration ([Ca(2+)](i)) in a Ca(2+)-free medium from 30 to approximately 80 nM. This [Ca(2+)](i) increase declined slowly, giving rise to a modest elevation of [Ca(2+)](i) that persisted for >5 min. The inhibitory effects of PMA and TMX on channel activity were abolished when tested in Tg-treated cells in a Ca(2+)-free medium. However, when the Ca(2+) ionophore, ionomycin, was applied with Tg, PMA and TMX retained their inhibitory effect on L-type Ca(2+) channel activity, suggesting that a lower amplitude and prolonged release of Ca(2+) stores is necessary for abrogating PKC-mediated inhibition of LCC. Cyclosporin A (5 microM) and ascomycin (5 microM), inhibitors of the Ca(2+)/calmodulin-dependent protein phosphatase, calcineurin, fully restored the inhibitory effect of PMA and TMX on channel activity. Addition of 1mM CaCl(2) to the Tg-treated cells increased [Ca(2+)](i) to approximately 165 nM and also restored the inhibitory effects of PMA and TMX. These results indicate that a small, relatively prolonged [Ca(2+)](i) increase elicited by passive depletion of internal Ca(2+) stores led to activation of calcineurin, giving rise to an increase in protein phosphatase activity that counteracted the inhibitory effects of PKC on channel activity. A larger increase in [Ca(2+)](i) via store-dependent Ca(2+) entry enhanced the activity of PKC sufficiently to overcome the protein phosphatase activity of calcineurin. This study is the first to demonstrate that the regulation of L-type Ca(2+) channels in a myocyte model involves a balance between the differential Ca(2+) sensitivities and opposing actions of PKC and calcineurin.