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Background and Objectives: Anterior column realignment (ACR) is a powerful minimally invasive surgery (MIS) technique to restore sagittal alignment in adult spinal deformity (ASD). This can accomplish similar segmental lordosis restoration as 3-column osteotomy with less blood loss and comparable complication rates. ACR can be performed at adjacent disease segments in the proximal lumbar spine in revision cases. However, two-thirds of physiologic lordosis occurs between L4-S1, and concerns remain about altered lumbar morphology. We evaluated patients who underwent proximal lumbar ACR for iatrogenic flatback deformity., Methods: A total of 19 consecutive patients who underwent L1-2 or L2-3 ACR were retrospectively analyzed. All patients were treated with lateral MIS interbody technique, followed by posterior reconstruction with Smith-Peterson osteotomy (SPO). Pre- and post-operative radiographic and clinical outcomes were obtained., Results: Mean follow-up was 19-months. All but one patient had a history of prior lumbar or lumbo-sacral fusion. SVA and PI-LL decreased from 11.9 cm to 6.1 cm (p<0.0001) and 34.2° to 12.8° (p<0.0001). Segmental lordosis increased from -2.7° to 21.9° (p<0.0001). Proximal lumbar lordosis (PLL) increased from -0.4° to 22.6° (p<0.0001), and lordosis distribution index (LDI) decreased from 79.5% to 48.9% (p<0.0001). Mean ODI and NPRS back pain decreased from 58.0 to 36.2 (p=0.0041) and 7.9 to 3.4 (p<0.0001). PROMIS-10 Physical and Mental Health T-scores increased from 34.1 to 43.3 (p=0.0049) and 40.4 to 45.0 (p=0.0993). Major complication rate was 15.8%. One patient required revision for mechanical failure. There were no permanent neurological or vascular injuries., Conclusion: Proximal lumbar ACR plus SPO can achieve sagittal correction with low major complication rates in patients with ASD and prior distal fusion. Differentially increasing PLL and lowering LDI did not have deleterious effects on radiographic or clinical outcomes. Further work is needed to understand the effect of proximal ACR in the surgical management of ASD., (Copyright © 2024. Published by Elsevier Inc.)

Background: Traumatic high cervical spinal cord injury (SCI) can result in a devastating loss of functional respiration, leaving patients permanently dependent on mechanical ventilation. Nerve transfer is a promising reinnervation strategy that has the potential to restore connectivity in paralyzed distal muscles. The spinal accessory nerve (SAN) remains functional in most cases after high cervical SCI and can serve as a donor to reinnervate the phrenic nerve (PN), thereby improving diaphragmatic function., Observations: Information regarding thorough physical, electrodiagnostic, and pulmonary assessments to establish candidacy for nerve transfer, as well as the surgical procedure, was summarized with an illustrative case. The patient demonstrated improvement in pulmonary function testing but did not achieve independent respiration. A systematic literature review identified 3 studies with 9 additional patients who had undergone SAN-to-PN transfer. The nerve transfer meaningfully restored diaphragmatic function, improving pulmonary function tests and reducing ventilator dependency., Lessons: Respiratory dependency significantly impacts the quality of life of patients with a high cervical SCI. The use of the lower SAN motor branch for PN transfer is safe and does not result in a meaningful downgrade in trapezius function. Outcomes following this procedure are promising but heterogeneous, indicating a need for significant innovation and improvement for future therapies. https://thejns.org/doi/10.3171/CASE24236.

Background: Ultra-minimally invasive percutaneous lumbar interbody fusion (percLIF) has been demonstrated to further minimize tissue trauma and has been associated with improved clinical outcomes including decreased blood loss, post-operative pain and length of stay when compared to minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) surgery. A single-institution retrospective study was conducted to investigate whether 1-level percLIF is associated with decreased narcotic consumption compared to 1-level MIS-TLIF in the first 24-hour following surgery., Methods: A retrospective study of patients undergoing either single-level percLIF or MIS-TLIF from January 2018 to December 2021. Opioid consumption in the 24-hour following surgery was converted into total morphine milligram equivalents (MME). The primary outcome used univariate and multivariate regression analysis to compare MME consumption between the MIS-TLIF and percLIF groups. Secondary outcome variables included, estimated blood loss, total intraoperative MME, MME at discharge, MME at 30 days post-op, exiting nerve root injury, post-anesthesia care unit (PACU) visual analogue scale (VAS) score at handoff, time to first ambulation, distance ambulated post-operative day one and hospital length of stay., Results: A total of 51 patients (21 percLIF vs. 30 MIS-TLIF) were included in the study. Univariate regression analysis revealed that on average patients who underwent percLIF had a 24-hour postoperative MME -50.8 mg (95% CI: -91.6, -10) lower than those who had MIS-TLIF (P=0.02). On multivariable analysis, after adjusting for sex and age, 24-hour postoperative MME closely failed to meet statistical significance (P=0.06) with an average of -40.8 mg (95% CI: -83.2, 1.6) MME in percLIF patients compared to MIS-TLIF. There was no statistically significant difference in MME between MIS-TLIF and percLIF at the time of discharge and at 30 days post-op., Conclusions: In the setting of the current opioid epidemic in the United States and increased numbers of patients undergoing lumbar interbody fusion, spine surgeons must continue to do their part helping reduce the need for opioid prescriptions for postoperative pain management. New "ultra-MIS" techniques such as percLIF allow surgeons to further decrease tissue trauma, which should lead to reduced need for post-operative narcotic requirements., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jss.amegroups.com/article/view/10.21037/jss-23-132/coif). All authors report that the study was supported in part by Grant Number UL1TR002553 from the National Center for Advancing Translational Sciences (NCATS), the grant does not directly support the work but they wish to acknowledge this support since the grant provides funding for the infrastructure in the BERD methods Core. T.W. has received consulting fees from Spineology. P.G. does teach and consult for DePuy spine; does consult and speak for Pacira Bioscience with respect to the use of liposomal bupivacaine in spine surgery; and has invested (<1%) in Restore3D and Medcura, neither of which make and products relevant to this study. The authors have no other conflicts of interest to declare., (2024 Journal of Spine Surgery. All rights reserved.)

Background and Objectives: Advanced diffusion-weighted MRI (DWI) modeling, such as diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI), may help guide rehabilitation strategies after surgical decompression for cervical spondylotic myelopathy (CSM). Currently, however, postoperative DWI is difficult to interpret, owing to signal distortions from spinal instrumentation. Therefore, we examined the relationship between postoperative DTI/DBSI-extracted from the rostral C3 spinal level-and clinical outcome measures at 2-year follow-up after decompressive surgery for CSM., Methods: Fifty patients with CSM underwent complete clinical and DWI evaluation-followed by DTI/DBSI analysis-at baseline and 2-year follow-up. Clinical outcomes included the modified Japanese Orthopedic Association score and comprehensive patient-reported outcomes. DTI metrics included apparent diffusion coefficient, fractional anisotropy, axial diffusivity, and radial diffusivity. DBSI metrics evaluated white matter tracts through fractional anisotropy, fiber fraction, axial diffusivity, and radial diffusivity as well as extra-axonal pathology through restricted and nonrestricted fraction. Cross-sectional Spearman's correlations were used to compare postoperative DTI/DBSI metrics with clinical outcomes., Results: Twenty-seven patients with CSM, including 15, 7, and 5 with mild, moderate, and severe disease, respectively, possessed complete baseline and postoperative DWI scans. At 2-year follow-up, there were 10 significant correlations among postoperative DBSI metrics and postoperative clinical outcomes compared with 3 among postoperative DTI metrics. Of the 13 significant correlations, 7 involved the neck disability index (NDI). The strongest relationships were between DBSI axial diffusivity and NDI (r = 0.60, P < .001), DBSI fiber fraction and NDI (rs = -0.58, P < .001), and DBSI restricted fraction and NDI (rs = 0.56, P < .001). The weakest correlation was between DTI apparent diffusion coefficient and NDI (r = 0.35, P = .02)., Conclusion: Quantitative measures of spinal cord microstructure after surgery correlate with postoperative neurofunctional status, quality of life, and pain/disability at 2 years after decompressive surgery for CSM. In particular, DBSI metrics may serve as meaningful biomarkers for postoperative disease severity for patients with CSM., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Cervical spinal cord injury (SCI) causes devastating loss of upper limb function and independence. Restoration of upper limb function can have a profound impact on independence and quality of life. In low-cervical SCI (level C5-C8), upper limb function can be restored via reinnervation strategies such as nerve transfer surgery. The translation of recovered upper limb motor function into functional independence in activities of daily living (ADLs), however, remains unknown in low cervical SCI (i.e., tetraplegia). The objective of this study was to evaluate the association of patterns in upper limb motor recovery with functional independence in ADLs. This will then inform prioritization of reinnervation strategies focused to maximize function in patients with tetraplegia. This retrospective study performed a secondary analysis of patients with low cervical (C5-C8) enrolled in the SCI Model Systems (SCIMS) database. Baseline neurological examinations and their association with functional independence in major ADLs-i.e., eating, bladder management, and transfers (bed/wheelchair/chair)-were evaluated. Motor functional recovery was defined as achieving motor strength, in modified research council (MRC) grade, of ≥ 3 /5 at one year from ≤ 2/5 at baseline. The association of motor function recovery with functional independence at one-year follow-up was compared in patients with recovered elbow flexion (C5), wrist extension (C6), elbow extension (C7), and finger flexion (C8). A multi-variable logistic regression analysis, adjusting for known factors influencing recovery after SCI, was performed to evaluate the impact of motor function at one year on a composite outcome of functional independence in major ADLs. Composite outcome was defined as functional independence measure score of 6 or higher (complete independence) in at least two domains among eating, bladder management, and transfers. Between 1992 and 2016, 1090 patients with low cervical SCI and complete neurological/functional measures were included. At baseline, 67% of patients had complete SCI and 33% had incomplete SCI. The majority of patients were dependent in eating, bladder management, and transfers. At one-year follow-up, the largest proportion of patients who recovered motor function in finger flexion (C8) and elbow extension (C7) gained independence in eating, bladder management, and transfers. In multi-variable analysis, patients who had recovered finger flexion (C8) or elbow extension (C7) had higher odds of gaining independence in a composite of major ADLs (odds ratio [OR] = 3.13 and OR = 2.87, respectively, p  < 0.001). Age 60 years (OR = 0.44, p  = 0.01), and complete SCI (OR = 0.43, p  = 0.002) were associated with reduced odds of gaining independence in ADLs. After cervical SCI, finger flexion (C8) and elbow extension (C7) recovery translate into greater independence in eating, bladder management, and transfers. These results can be used to design individualized reinnervation plans to reanimate upper limb function and maximize independence in patients with low cervical SCI.

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

Background and Objectives: There has been a rise in minimally invasive methods to access the intervertebral disk space posteriorly given their decreased tissue destruction, lower blood loss, and earlier return to work. Two such options include the percutaneous lumbar interbody fusion through the Kambin triangle and the endoscopic transfacet approach. However, without accurate preoperative visualization, these approaches carry risks of damaging surrounding structures, especially the nerve roots. Using novel segmentation technology, our goal was to analyze the anatomic borders and relative sizes of the safe triangle, trans-Kambin, and the transfacet corridors to assist surgeons in planning a safe approach and determining cannula diameters., Methods: The areas of the safe triangle, Kambin, and transfacet corridors were measured using commercially available software (BrainLab, Munich, Germany). For each approach, the exiting nerve root, traversing nerve roots, theca, disk, and vertebrae were manually segmented on 3-dimensional T2-SPACE magnetic resonance imaging using a region-growing algorithm. The triangles' borders were delineated ensuring no overlap between the area and the nerves., Results: A total of 11 patients (65.4 ± 12.5 years, 33.3% female) were retrospectively reviewed. The Kambin, safe, and transfacet corridors were measured bilaterally at the operative level. The mean area (124.1 ± 19.7 mm2 vs 83.0 ± 11.7 mm2 vs 49.5 ± 11.4 mm2) and maximum permissible cannula diameter (9.9 ± 0.7 mm vs 6.8 ± 0.5 mm vs 6.05 ± 0.7 mm) for the transfacet triangles were significantly larger than Kambin and the traditional safe triangles, respectively (P < .001)., Conclusion: We identified, in 3-dimensional, the borders for the transfacet corridor: the traversing nerve root extending inferiorly until the caudal pedicle, the theca medially, and the exiting nerve root superiorly. These results illustrate the utility of preoperatively segmenting anatomic landmarks, specifically the nerve roots, to help guide decision-making when selecting the optimal operative approach., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Background: Considerations of the sacroiliac joint (SIJ) and its role in causing lower back and limb pain have taken a secondary role ever since Mixter and Barr's hallmark article in 1934 on the herniated nucleus pulposus. However, recent literature has highlighted the contribution of sacroiliac joint degeneration in the development of failed back surgery syndrome (FBSS), especially in patients undergoing lumbar or lumbosacral spinal fusion surgeries. Many reports have studied the anatomy, physiology, and clinical significance of the sacroiliac joint, but none have linked its dysfunction with other spinal deformities., Case Description: A 63-year-old female with a history of multiple complex instrumented spinal fusions presented to our institution with progressive leftward coronal imbalance despite successful arthrodesis from T3 through S1. She was initially treated with decompression and reimplantation, but adjacent segment disease at the SIJ led to laxity, distal failure, and a worsening coronal deformity. A mechanical fall after her decompression surgery led to a dramatically increased coronal imbalance, which was ultimately treated using Lenke's kickstand rod technique. At 3.5 years follow up, the patient's coronal balance remains stable., Conclusion: Few studies have related SIJ degeneration and laxity with spinal deformity. Our case describes SIJ degeneration that evolved to joint laxity, which ultimately produced a leftward coronal imbalance according to the adjacent segment disease mechanism. Additionally, we describe the use of a kickstand rod to effectively correct the coronal imbalance, reduce pain levels, promote SIJ arthrodesis, and prevent further SIJ-related issues without significant complications over 3 years post-operation.

Surgical correction of fixed kyphotic deformity or severe sagittal imbalance traditionally involves three column osteotomies, which are associated with high morbidity rates. Anterior column realignment (ACR) has emerged as a minimally invasive alternative for restoring segmental lordosis. This technique involves a lateral approach and release of the anterior longitudinal ligament (ALL), followed by placement of a hyperlordotic interbody cage. In this study, we present a successful case of minimally invasive ACR for the treatment of flatback deformity and adjacent segment disease in a patient with prior L2-S1 fusion. Imaging revealed a flatback deformity, sagittal vertical axis elevation, and spinopelvic disharmony. The patient underwent a multistage procedure involving a lateral retropleural approach for ACR and interbody fusion, followed by open posterior instrumented fusion and vertebroplasties. Postoperatively, the patient experienced significant pain relief and improvement in lumbar lordosis, pelvic tilt, and pelvic incidence-lumbar lordosis mismatch. ACR combined with posterior release allows for manipulation of all three spinal columns, leading to spine reconstruction and improved spinopelvic harmony. We discuss the advantages of ACR, including its minimally invasive nature and potential benefits for patients with sagittal deformities. The presented surgical technique demonstrates the feasibility and efficacy of minimally invasive ACR in addressing flatback deformity and adjacent segment disease., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jss.amegroups.com/article/view/10.21037/jss-23-45/coif). KDT serves as an unpaid editorial board member of Journal of Spine Surgery from December 2022 to November 2024. KDT reports consultant fees from DePuy Synthes, NuVasive, Accelus, Bioventus, and Cerapedics, as well as honoraria from SI-Bone, and is stockholder of NuVasive and Prioprio, outside the submitted work. CS reports consulting fees from NuVasive, Medtronic, SI Bone, and Proprio; royalties from NuVasive, Medtronic and SI Bone; and is stockholder of NuVasive and Prioprio; outside the submitted work. The other authors have no conflicts of interest to declare., (2023 Journal of Spine Surgery. All rights reserved.)

Background: Chronic entrapment neuropathy results in a clinical syndrome ranging from mild pain to debilitating atrophy. There remains a lack of objective metrics that quantify nerve dysfunction and guide surgical decision-making. Mechanomyography (MMG) reflects mechanical motor activity after stimulation of neuromuscular tissue and may indicate underlying nerve dysfunction., Objective: To evaluate the role of MMG as a surgical adjunct in treating chronic entrapment neuropathies., Methods: Patients 18 years or older with cubital tunnel syndrome (n = 8) and common peroneal neuropathy (n = 15) were enrolled. Surgical decompression of entrapped nerves was performed with intraoperative MMG of the hypothenar and tibialis anterior muscles. MMG stimulus thresholds (MMG-st) were correlated with compound muscle action potential (CMAP), motor nerve conduction velocity, baseline functional status, and clinical outcomes., Results: After nerve decompression, MMG-st significantly reduced, the mean reduction of 0.5 mA (95% CI: 0.3-0.7, P < .001). On bivariate analysis, MMG-st exhibited significant negative correlation with common peroneal nerve CMAP ( P < .05), but no association with ulnar nerve CMAP and motor nerve conduction velocity. On preoperative electrodiagnosis, 60% of nerves had axonal loss and 40% had conduction block. The MMG-st was higher in the nerves with axonal loss as compared with the nerves with conduction block. MMG-st was negatively correlated with preoperative hand strength (grip/pinch) and foot-dorsiflexion/toe-extension strength ( P < .05). At the final visit, MMG-st significantly correlated with pain, PROMIS-10 physical function, and Oswestry Disability Index ( P < .05)., Conclusion: MMG-st may serve as a surgical adjunct indicating axonal integrity in chronic entrapment neuropathies which may aid in clinical decision-making and prognostication of functional outcomes., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Objective: Diffusion basis spectrum imaging (DBSI) has shown promise in evaluating cervical spinal cord structural changes in patients with cervical spondylotic myelopathy (CSM). DBSI may also be valuable in the postoperative setting by serially tracking spinal cord microstructural changes following decompressive cervical spine surgery. Currently, there is a paucity of studies investigating this topic, likely because of challenges in resolving signal distortions from spinal instrumentation. Therefore, the objective of this study was to assess the feasibility of DBSI metrics extracted from the C3 spinal level to evaluate CSM patients postoperatively., Methods: Fifty CSM patients and 20 healthy controls were enrolled in a single-center prospective study between 2018 and 2020. All patients and healthy controls underwent preoperative and postoperative diffusion-weighted MRI (dMRI) at a 2-year follow-up. All CSM patients underwent decompressive cervical surgery. The modified Japanese Orthopaedic Association (mJOA) score was used to categorize CSM patients as having mild, moderate, or severe myelopathy. DBSI metrics were extracted from the C3 spinal cord level to minimize image artifact and reduce partial volume effects. DBSI anisotropic tensors evaluated white matter tracts through fractional anisotropy, axial diffusivity, radial diffusivity, and fiber fraction. DBSI isotropic tensors assessed extra-axonal pathology through restricted and nonrestricted fractions., Results: Of the 50 CSM patients, both baseline and postoperative dMR images with sufficient quality for analysis were obtained in 27 patients. These included 15 patients with mild CSM (mJOA scores 15-17), 7 with moderate CSM (scores 12-14), and 5 with severe CSM (scores 0-11), who were followed up for a mean of 23.5 (SD 4.1, range 11-31) months. All preoperative C3-level DBSI measures were significantly different between CSM patients and healthy controls (p < 0.05), except DBSI fractional anisotropy (p = 0.31). At the 2-year follow-up, the same significance pattern was found between CSM patients and healthy controls, except DBSI radial diffusivity was no longer statistically significant (p = 0.75). When assessing change (i.e., postoperative - preoperative values) in C3-level DBSI measures, CSM patients exhibited significant decreases in DBSI radial diffusivity (p = 0.02), suggesting improvement in myelin integrity (i.e., remyelination) at the 2-year follow-up. Among healthy controls, there was no significant difference in DBSI metrics over time., Conclusions: DBSI metrics derived from dMRI at the C3 spinal level can be used to provide meaningful insights into representations of the spinal cord microstructure of CSM patients at baseline and 2-year follow-up. DBSI may have the potential to characterize white matter tract recovery and inform outcomes following decompressive cervical surgery for CSM.

Study Design: Retrospective Case-Series., Objectives: Due to heterogeneity in previous studies, the effect of MI-TLIF on postoperative segmental lordosis (SL) and lumbar lordosis (LL) remains unclear. Therefore, we aim to identify radiographic factors associated with lordosis after surgery in a homogenous series of MI-TLIF patients., Methods: A single-center retrospective review identified consecutive patients who underwent single-level MI-TLIF for grade 1 degenerative spondylolisthesis from 2015-2020. All surgeries underwent unilateral facetectomies and a contralateral facet release with expandable interbody cages. PROs included the ODI and NRS-BP for low-back pain. Radiographic measures included SL, disc height, percent spondylolisthesis, cage positioning, LL, PI-LL mismatch, sacral-slope, and pelvic-tilt. Surgeries were considered "lordosing" if the change in postoperative SL was ≥ +4° and "kyphosing" if ≤ -4°. Predictors of change in SL/LL were evaluated using Pearson's correlation and multivariable regression., Results: A total of 73 patients with an average follow-up of 22.5 (range 12-61) months were included. Patients experienced significant improvements in ODI (29% ± 22% improvement, P < .001) and NRS-BP (3.3 ± 3 point improvement, P < .001). There was a significant increase in mean SL (Δ3.43° ± 4.37°, P < .001) while LL (Δ0.17° ± 6.98°, P > .05) remained stable. Thirty-eight (52%) patients experienced lordosing MI-TLIFs, compared to 4 (5%) kyphosing and 31 (43%) neutral MI-TLIFs. A lower preoperative SL and more anterior cage placement were associated with the greatest improvement in SL (β = -.45° P = .001, β = 15.06° P < .001, respectively)., Conclusions: In our series, the majority of patients experienced lordosing or neutral MI-TLIFs (n = 69, 95%). Preoperative radiographic alignment and anterior cage placement were significantly associated with target SL following MI-TLIF., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

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

Background Context: Patients with cervical spine disease suffer from upper limb disability. At present, no clinical benchmarks exist for clinically meaningful change in the upper limb function following cervical spine surgery., Purpose: Primary: to establish clinically meaningful metrics; the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) of upper limb functional improvement in patients following cervical spine surgery. Secondary: to identify the prognostic factors of MCID and SCB of upper limb function following cervical spine surgery., Study Design: Retrospective cohort study., Patient Sample: Adult patients ≥18 years of age who underwent cervical spine surgery from 2012 to 2016., Outcome Measures: Patient-reported outcomes: Neck disability index (NDI) and Disabilities of Arm, Shoulder, and Hand (DASH)., Methods: MCID was defined as minimal improvement and SCB as substantial improvement in the DASH score at last follow-up. The anchor-based methods (ROC analyses) defined optimal MCID and SCB thresholds with area under curve (AUC) in discriminating improved vs. non-improved patients. The MCID was also calculated by distribution-based methods: half standard-deviation (0.5-SD) and standard error of the mean (SEM) method. A multivariable logistic regression evaluated the impact of baseline factors in achieving the MCID and SCB in DASH following cervical spine surgery., Results: Between 2012 and 2016, 1,046 patients with average age of 57±11.3 years, 53% males, underwent cervical spine surgery. Using the ROC analysis, the threshold for MCID was -8 points with AUC of 0.73 (95% CI: 0.67-0.79) and the SCB was -18 points with AUC of 0.88 (95% confidence interval [CI]: 0.85-0.91). The MCID was -11 points by 0.5-SD and -12 points by SEM-method. On multivariable analysis, patients with myelopathy had lower odds of achieving MCID and SCB, whereas older patients and those with ≥6 months duration of symptoms had lower odds of achieving DASH MCID and SCB respectively., Conclusions: In patients undergoing cervical spine surgery, MCID of -8 points and SCB of -18 points in DASH improvement may be considered clinically significant. These metrics may enable evaluation of minimal and substantial improvement in the upper extremity function following cervical spine surgery., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: High cervical spinal cord injury (SCI) results in complete loss of upper-limb function, resulting in debilitating tetraplegia and permanent disability. Spontaneous motor recovery occurs to varying degrees in some patients, particularly in the 1st year postinjury. However, the impact of this upper-limb motor recovery on long-term functional outcomes remains unknown. The objective of this study was to characterize the impact of upper-limb motor recovery on the degree of long-term functional outcomes in order to inform priorities for research interventions that restore upper-limb function in patients with high cervical SCI., Methods: A prospective cohort of high cervical SCI (C1-4) patients with American Spinal Injury Association Impairment Scale (AIS) grade A-D injury and enrolled in the Spinal Cord Injury Model Systems Database was included. Baseline neurological examinations and functional independence measures (FIMs) in feeding, bladder management, and transfers (bed/wheelchair/chair) were evaluated. Independence was defined as score ≥ 4 in each of the FIM domains at 1-year follow-up. At 1-year follow-up, functional independence was compared among patients who gained recovery (motor grade ≥ 3) in elbow flexors (C5), wrist extensors (C6), elbow extensors (C7), and finger flexors (C8). Multivariable logistic regression evaluated the impact of motor recovery on functional independence in feeding, bladder management, and transfers., Results: Between 1992 and 2016, 405 high cervical SCI patients were included. At baseline, 97% of patients had impaired upper-limb function with total dependence in eating, bladder management, and transfers. At 1 year of follow-up, the largest proportion of patients who gained independence in eating, bladder management, and transfers had recovery in finger flexion (C8) and wrist extension (C6). Elbow flexion (C5) recovery had the lowest translation to functional independence. Patients who achieved elbow extension (C7) were able to transfer independently. On multivariable analysis, patients who gained elbow extension (C7) and finger flexion (C8) were 11 times more likely to gain functional independence (OR 11, 95% CI 2.8-47, p < 0.001) and patients who gained wrist extension (C6) were 7 times more likely to gain functional independence (OR 7.1, 95% CI 1.2-56, p = 0.04). Older age (≥ 60 years) and motor complete SCI (AIS grade A-B) reduced the likelihood of gaining independence., Conclusions: After high cervical SCI, patients who gained elbow extension (C7) and finger flexion (C8) had significantly greater independence in feeding, bladder management, and transfers than those with recovery in elbow flexion (C5) and wrist extension (C6). Recovery of elbow extension (C7) also increased the capability for independent transfers. This information can be used to set patient expectations and prioritize interventions that restore these upper-limb functions in patients with high cervical SCI.

Study Design: Prospective cohort study., Objective: Apply a machine learning clustering algorithm to baseline imaging data to identify clinically relevant cervical spondylotic myelopathy (CSM) patient phenotypes., Summary of Background Data: A major shortcoming in improving care for CSM patients is the lack of robust quantitative imaging tools to guide surgical decision-making. Advanced diffusion-weighted magnetic resonance imaging (MRI) techniques, such as diffusion basis spectrum imaging (DBSI), may help address this limitation by providing detailed evaluations of white matter injury in CSM., Methods: Fifty CSM patients underwent comprehensive clinical assessments and diffusion-weighted MRI, followed by DBSI modeling. DBSI metrics included fractional anisotropy, axial and radial diffusivity, fiber fraction, extra-axonal fraction, restricted fraction, and nonrestricted fraction. Neurofunctional status was assessed by the modified Japanese Orthopedic Association, myelopathic disability index, and disabilities of the arm, shoulder, and hand. Quality-of-life was measured by the 36-Item Short Form Survey physical component summary and mental component summary. The neck disability index was used to measure self-reported neck pain. K-means clustering was applied to baseline DBSI measures to identify 3 clinically relevant CSM disease phenotypes. Baseline demographic, clinical, radiographic, and patient-reported outcome measures were compared among clusters using one-way analysis of variance (ANOVA)., Results: Twenty-three (55%) mild, 9 (21%) moderate, and 10 (24%) severe myelopathy patients were enrolled. Eight patients were excluded due to MRI data of insufficient quality. Of the remaining 42 patients, 3 groups were generated by k-means clustering. When compared with clusters 1 and 2, cluster 3 performed significantly worse on the modified Japanese Orthopedic Association and all patient-reported outcome measures (P<0.001), except the 36-Item Short Form Survey mental component summary (P>0.05). Cluster 3 also possessed the highest proportion of non-Caucasian patients (43%, P=0.04), the worst hand dynamometer measurements (P<0.05), and significantly higher intra-axonal axial diffusivity and extra-axonal fraction values (P<0.001)., Conclusions: Using baseline imaging data, we delineated a clinically meaningful CSM disease phenotype, characterized by worse neurofunctional status, quality-of-life, and pain, and more severe imaging markers of vasogenic edema., Level of Evidence: II., Competing Interests: W.Z.R. is a consultant for Depuy/Synthes and Globus Spine. W.Z.R. has grant support from the Department of Defense, National Institutes of Health, Defense Advanced Research Projects Agency. The remaining authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Mechanomyography (MMG) is a novel intraoperative tool to detect and quantify nerve activity with high sensitivity as compared with traditional electromyographic recordings. MMG reflects the mechanical vibrations of single motor units detected through accelerometer sensors after direct motor neuron stimulation., Objective: To determine the feasibility of applying intraoperative MMG during peripheral nerve surgery., Methods: A total of 20 consecutive patients undergoing surgical decompression of the ulnar nerve at the cubital tunnel or common peroneal nerve at the fibular head were included in this study. Intraoperatively, the common peroneal and ulnar nerves were directly stimulated through the MMG electrode probe starting at 0.1 mA threshold and increasing by 0.1 mA increments until target muscle activity was noted. The lowest threshold current required to elicit a muscle response was recorded before decompression and after proximal and distal nerve decompression., Results: Of the patients, 80% (16/20) had MMG signals detected and recorded. Four patients were unable to have MMG signal detected despite direct nerve visualization and complete neurolysis. The mean predecompression stimulus threshold was 1.59 ± 0.19 mA. After surgical decompression, improvement in the mean MMG stimulus threshold was noted (0.47 ± 0.03 mA, P = .0002). Postoperatively, all patients endorsed symptomatic improvement with no complications., Conclusion: MMG may provide objective guidance for the intraoperative determination of the extent of nerve decompression. Lower stimulus thresholds may represent increased sparing of axonal tissue. Future work should focus on validating normative values of MMG stimulus thresholds in various nerves and establishing clinical associations with functional outcomes., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Background Context: A major shortcoming in improving care for cervical spondylotic myelopathy (CSM) patients is the lack of robust quantitative imaging tools to guide surgical decision-making. Diffusion basis spectrum imaging (DBSI), an advanced diffusion-weighted MRI technique, provides objective assessments of white matter tract integrity that may help prognosticate outcomes in patients undergoing surgery for CSM., Purpose: To examine the ability of DBSI to predict clinically important CSM outcome measures at 2-years follow-up., Study Design/setting: Prospective cohort study., Patient Sample: Patients undergoing decompressive cervical surgery for CSM., Outcome Measures: Neurofunctional status was assessed by the mJOA, MDI, and DASH. Quality-of-life was measured by the SF-36 PCS and SF-36 MCS. The NDI evaluated self-reported neck pain, and patient satisfaction was assessed by the NASS satisfaction index., Methods: Fifty CSM patients who underwent cervical decompressive surgery were enrolled. Preoperative DBSI metrics assessed white matter tract integrity through fractional anisotropy, fiber fraction, axial diffusivity, and radial diffusivity. To evaluate extra-axonal diffusion, DBSI measures restricted and nonrestricted fractions. Patient-reported outcome measures were evaluated preoperatively and up to 2-years follow-up. Support vector machine classification algorithms were used to predict surgical outcomes at 2-years follow-up. Specifically, three feature sets were built for each of the seven clinical outcome measures (eg, mJOA), including clinical only, DBSI only, and combined feature sets., Results: Twenty-seven mild (mJOA 15-17), 12 moderate (12-14) and 11 severe (0-11) CSM patients were enrolled. Twenty-four (60%) patients underwent anterior decompressive surgery compared with 16 (40%) posterior approaches. The mean (SD) follow-up was 23.2 (5.6, range 6.1-32.8) months. Feature sets built on combined data (ie, clinical+DBSI metrics) performed significantly better for all outcome measures compared with those only including clinical or DBSI data. When predicting improvement in the mJOA, the clinically driven feature set had an accuracy of 61.9 [61.6, 62.5], compared with 78.6 [78.4, 79.2] in the DBSI feature set, and 90.5 [90.2, 90.8] in the combined feature set., Conclusions: When combined with key clinical covariates, preoperative DBSI metrics predicted improvement after surgical decompression for CSM with high accuracy for multiple outcome measures. These results suggest that DBSI may serve as a noninvasive imaging biomarker for CSM valuable in guiding patient selection and informing preoperative counseling., Level of Evidence: II., Competing Interests: Declarations of Competing Interests One or more of the authors declare financial or professional relationships on ICMJE-TSJ disclosure forms., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Direct current electrical stimulation may serve as a promising nonpharmacological adjunct promoting osteogenesis and fusion. The aim of this study was to evaluate the utility of electroactive spine instrumentation in the focal delivery of therapeutic electrical stimulation to enhance lumbar bone formation and interbody fusion., Methods: A finite element model of adult human lumbar spine (L4-L5) instrumented with single-level electroactive pedicle screws was simulated. Direct current electrical stimulation was routed through anodized electroactive pedicle screws to target regions of fusion. The electrical fields generated by electroactive pedicle screws were evaluated in various tissue compartments including isotropic tissue volumes, cortical, and trabecular bone. Electrical field distributions at various stimulation amplitudes (20-100 µA) and pedicle screw anodization patterns were analyzed in target regions of fusion (eg, intervertebral disc space, vertebral body, and pedicles)., Results: Electrical stimulation with electroactive pedicle screws at various stimulation amplitudes and anodization patterns enabled modulation of spatial distribution and intensity of electric fields within the target regions of lumbar spine. Anodized screws (50%) vs unanodized screws (0%) induced high-amplitude electric fields within the intervertebral disc space and vertebral body but negligible electric fields in spinal canal. Direct current electrical stimulation via anodized screws induced electrical fields, at therapeutic threshold of >1 mV/cm, sufficient for osteoinduction within the target interbody region., Conclusions: Selective anodization of electroactive pedicle screws may enable focal delivery of therapeutic electrical stimulation in the target regions in human lumbar spine. This study warrants preclinical and clinical testing of integrated electroactive system in inducing target lumbar fusion in vivo., Clinical Relevance: The findings of this study provide a foundation for clinically investigating electroactive intrumentation to enhance spine fusion., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2023 ISASS. To see more or order reprints or permissions, see http://ijssurgery.com.)

Background: Diffusion basis spectrum imaging (DBSI) is a noninvasive quantitative imaging modality that may improve understanding of cervical spondylotic myelopathy (CSM) pathology through detailed evaluations of spinal cord microstructural compartments., Objective: To determine the utility of DBSI as a biomarker of CSM disease severity., Methods: A single-center prospective cohort study enrolled 50 patients with CSM and 20 controls from 2018 to 2020. All patients underwent clinical evaluation and diffusion-weighted MRI, followed by diffusion tensor imaging and DBSI analyses. Diffusion-weighted MRI metrics assessed white matter integrity by fractional anisotropy, axial diffusivity, radial diffusivity, and fiber fraction. In addition, DBSI further evaluates extra-axonal changes by isotropic restricted and nonrestricted fraction. Including an intra-axonal diffusion compartment, DBSI improves estimations of axonal injury through intra-axonal axial diffusivity. Patients were categorized into mild, moderate, and severe CSM using modified Japanese Orthopedic Association classifications. Imaging parameters were compared among patient groups using independent samples t tests and ANOVA., Results: Twenty controls, 27 mild (modified Japanese Orthopedic Association 15-17), 12 moderate (12-14), and 11 severe (0-11) patients with CSM were enrolled. Diffusion tensor imaging and DBSI fractional anisotropy, axial diffusivity, and radial diffusivity were significantly different between control and patients with CSM ( P < .05). DBSI fiber fraction, restricted fraction, and nonrestricted fraction were significantly different between groups ( P < .01). DBSI intra-axonal axial diffusivity was lower in mild compared with moderate (mean difference [95% CI]: 1.1 [0.3-2.1], P < .01) and severe (1.9 [1.3-2.4], P < .001) CSM., Conclusion: DBSI offers granular data on white matter tract integrity in CSM that provide novel insights into disease pathology, supporting its potential utility as a biomarker of CSM disease progression., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Background: Despite an increased understanding of the impact of socioeconomic status on neurosurgical outcomes, the impact of neighborhood-level social determinants on lumbar spine surgery patient-reported outcomes remains unknown., Objective: To evaluate the impact of geographic social deprivation on physical and mental health of lumbar surgery patients., Methods: A single-center retrospective cohort study analyzing patients undergoing lumbar surgery for degenerative disease from 2015 to 2018 was performed. Surgeries were categorized as decompression only or decompression with fusion. The area deprivation index was used to define social deprivation. Study outcomes included preoperative and change in Patient-Reported Outcomes Measurement (PROMIS) physical function (PF), pain interference (PI), depression, and anxiety (mean follow-up: 43.3 weeks). Multivariable imputation was performed for missing data. One-way analysis of variance and multivariable linear regression were used to evaluate the association between area deprivation index and PROMIS scores., Results: In our cohort of 2010 patients, those with the greatest social deprivation had significantly worse mean preoperative PROMIS scores compared with the least-deprived cohort (mean difference [95% CI]-PF: -2.5 [-3.7 to -1.4]; PI: 3.0 [2.0-4.1]; depression: 5.5 [3.4-7.5]; anxiety: 6.0 [3.8-8.2], all P < .001), without significant differences in change in these domains at latest follow-up (PF: +0.5 [-1.2 to 2.2]; PI: -0.2 [-1.7 to 2.1]; depression: -2 [-4.0 to 0.1]; anxiety: -2.6 [-4.9 to 0.4], all P > .05)., Conclusion: Lumbar spine surgery patients with greater social deprivation present with worse preoperative physical and mental health but experience comparable benefit from surgery than patients with less deprivation, emphasizing the need to further understand social and health factors that may affect both disease severity and access to care., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Study Design: Prospective cohort study., Objective: The aim was to assess the association between diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI) measures and cervical spondylotic myelopathy (CSM) clinical assessments at baseline and two-year follow-up., Summary of Background Data: Despite advancements in diffusion-weighted imaging, few studies have examined associations between diffusion magnetic resonance imaging (MRI) markers and CSM-specific clinical domains at baseline and long-term follow-up., Materials and Methods: A single-center prospective cohort study enrolled 50 CSM patients who underwent surgical decompression and 20 controls from 2018 to 2020. At initial evaluation, all patients underwent diffusion-weighted MRI acquisition, followed by DTI and DBSI analyses. Diffusion-weighted MRI metrics assessed white matter integrity by fractional anisotropy, axial diffusivity, radial diffusivity, and fiber fraction. To improve estimations of intra-axonal anisotropic diffusion, DBSI measures intra-/extra-axonal fraction and intra-axonal axial diffusivity. DBSI also evaluates extra-axonal isotropic diffusion by restricted and nonrestricted fraction. Clinical assessments were performed at baseline and two-year follow-up and included the modified Japanese Orthopedic Association (mJOA); 36-Item Short Form Survey physical component summary (SF-36 PCS); SF-36 mental component summary; neck disability index; myelopathy disability index; and disability of the arm, shoulder, and hand. Pearson correlation coefficients were computed to compare associations between DTI/DBSI and clinical measures. A False Discovery Rate correction was applied for multiple comparisons testing., Results: At baseline presentation, of 36 correlations analyzed between DTI metrics and CSM clinical measures, only DTI fractional anisotropy showed a positive correlation with SF-36 PCS ( r =0.36, P =0.02). In comparison, there were 30/81 (37%) significant correlations among DBSI and clinical measures. Increased DBSI axial diffusivity, intra-axonal axial diffusivity, intra-axonal fraction, restricted fraction, and extra-axonal anisotropic fraction were associated with worse clinical presentation (decreased mJOA; SF-36 PCS/mental component summary; and increased neck disability index; myelopathy disability index; disability of the arm, shoulder, and hand). At latest follow-up, increased preoperative DBSI intra-axonal axial diffusivity and extra-axonal anisotropic fraction were significantly correlated with improved mJOA., Conclusions: This findings demonstrate that DBSI measures may reflect baseline disease burden and long-term prognosis of CSM as compared with DTI. With further validation, DBSI may serve as a noninvasive biomarker following decompressive surgery., Level of Evidence: 3., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Importance: Traumatic cervical spinal cord injury (SCI) can result in debilitating paralysis. Following cervical SCI, accurate early prediction of upper limb recovery can serve an important role in guiding the appropriateness and timing of reconstructive therapies., Objective: To develop a clinical prediction rule to prognosticate upper limb functional recovery after cervical SCI., Design, Setting, and Participants: This prognostic study was a retrospective review of a longitudinal cohort study including patients enrolled in the National SCI model systems (SCIMS) database in US. Eligible patients were 15 years or older with tetraplegia (neurological level of injury C1-C8, American Spinal Cord Injury Association [ASIA] impairment scale [AIS] A-D), with early (within 1 month of SCI) and late (1-year follow-up) clinical examinations from 2011 to 2016. The data analysis was conducted from September 2021 to June 2022., Main Outcomes and Measures: The primary outcome was a composite of dependency in eating, bladder management, transfers, and locomotion domains of functional independence measure at 1-year follow-up. Each domain ranges from 1 to 7 with a lower score indicating greater functional dependence. Composite dependency was defined as a score of 4 or higher in at least 3 chosen domains. Multivariable logistic regression was used to predict the outcome based on early neurological variables. Discrimination was quantified using C statistics, and model performance was internally validated with bootstrapping and 10-fold cross-validation. The performance of the prediction score was compared with AIS grading. Data were split into derivation (2011-2014) and temporal-validation (2015-2016) cohorts., Results: Among 2373 patients with traumatic cervical SCI, 940 had complete 1-year outcome data (237 patients [25%] aged 60 years or older; 753 men [80%]). The primary outcome was present in 118 patients (13%), which included 92 men (78%), 83 (70%) patients who were younger than 60 years, and 73 (62%) patients experiencing AIS grade A SCI. The variables significantly associated with the outcome were age (age 60 years or older: OR, 2.31; 95% CI, 1.26-4.19), sex (men: OR, 0.60; 95% CI, 0.31-1.17), light-touch sensation at C5 (OR, 0.44; 95% CI, 0.44-1.01) and C8 (OR, 036; 95% CI, 0.24-0.53) dermatomes, and motor scores of the elbow flexors (C5) (OR, 0.74; 95% CI, 0.60-0.89) and wrist extensors (C6) (OR, 0.61; 95% CI, 0.49-0.75). A multivariable model including these variables had excellent discrimination in distinguishing dependent from independent patients in the temporal-validation cohort (C statistic, 0.90; 95% CI, 0.88-0.93). A clinical prediction score (range, 0 to 45 points) was developed based on these measures, with higher scores increasing the probability of dependency. The discrimination of the prediction score was significantly higher than from AIS grading (change in AUC, 0.14; 95% CI, 0.10-0.18; P < .001)., Conclusions and Relevance: The findings of this study suggest that this prediction rule may help prognosticate upper limb function following cervical SCI. This tool can be used to set patient expectations, rehabilitation goals, and aid decision-making regarding the appropriateness and timing for upper limb reconstructive surgeries.

Importance: Cervical spinal cord injury (SCI) causes devastating loss of upper extremity function and independence. Nerve transfers are a promising approach to reanimate upper limbs; however, there remains a paucity of high-quality evidence supporting a clinical benefit for patients with tetraplegia., Objective: To evaluate the clinical utility of nerve transfers for reanimation of upper limb function in tetraplegia., Design, Setting, and Participants: In this prospective case series, adults with cervical SCI and upper extremity paralysis whose recovery plateaued were enrolled between September 1, 2015, and January 31, 2019. Data analysis was performed from August 2021 to February 2022., Interventions: Nerve transfers to reanimate upper extremity motor function with target reinnervation of elbow extension and hand grasp, pinch, and/or release., Main Outcomes and Measures: The primary outcome was motor strength measured by Medical Research Council (MRC) grades 0 to 5. Secondary outcomes included Sollerman Hand Function Test (SHFT); Michigan Hand Outcome Questionnaire (MHQ); Disabilities of Arm, Shoulder, and Hand (DASH); and 36-Item Short Form Health Survey (SF-36) physical component summary (PCS) and mental component summary (MCS) scores. Outcomes were assessed up to 48 months postoperatively., Results: Twenty-two patients with tetraplegia (median age, 36 years [range, 18-76 years]; 21 male [95%]) underwent 60 nerve transfers on 35 upper limbs at a median time of 21 months (range, 6-142 months) after SCI. At final follow-up, upper limb motor strength improved significantly: median MRC grades were 3 (IQR, 2.5-4; P = .01) for triceps, with 70% of upper limbs gaining an MRC grade of 3 or higher for elbow extension; 4 (IQR, 2-4; P < .001) for finger extensors, with 79% of hands gaining an MRC grade of 3 or higher for finger extension; and 2 (IQR, 1-3; P < .001) for finger flexors, with 52% of hands gaining an MRC grade of 3 or higher for finger flexion. The secondary outcomes of SHFT, MHQ, DASH, and SF36-PCS scores improved beyond the established minimal clinically important difference. Both early (<12 months) and delayed (≥12 months) nerve transfers after SCI achieved comparable motor outcomes. Continual improvement in motor strength was observed in the finger flexors and extensors across the entire duration of follow-up., Conclusions and Relevance: In this prospective case series, nerve transfer surgery was associated with improvement of upper limb motor strength and functional independence in patients with tetraplegia. Nerve transfer is a promising intervention feasible in both subacute and chronic SCI.

Price transparency is an increasingly popular solution for high healthcare expenditures in the United States, but little is known about its potential to facilitate patient price shopping. Our objective was to analyze interhospital and interpayer price variability in spine surgery and spine imaging using newly public payer-specific negotiated charges (PNCs). We selected a subset of billing codes for spine surgery and spine imaging at 12 hospitals within a Saint Louis metropolitan area healthcare system. We then compared PNCs for these procedures and tested for significant differences in interhospital and interinsurer IQR using the Mann-Whitney U Test. We found significantly greater IQRs of PNCs as a factor of the insurance plan than as a factor of the hospital for cervical spinal fusions (interinsurer IQR $8256; interhospital IQR $533; P < .0001), noncervical spinal fusions (interinsurer IQR $28 423; interhospital IQR $5512; P < .001), computed tomographies of the lower spine (interinsurer IQR $595; interhospital IQR $113; P < .0001), and MRIs lower spinal canal (interinsurer IQR $1010; interhospital IQR $158; P < .0001). There was no significant difference between the interinsurer IQR and the interhospital IQR for lower spine x-rays (interinsurer IQR $107; interhospital IQR $67; P = .0543). Despite some between-hospital heterogeneity, we show significantly higher price variability between insurers than between hospitals. Our single system analysis limits our ability to generalize, but our results suggest that savings depend more on hospital and provider negotiations than patient price shopping, given the difficulty of switching insurers., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Objective: Local and regional radiographic outcomes following minimally invasive (MI) transforaminal lumbar interbody fusion (TLIF) versus open TLIF remain unclear. The purpose of this study was to provide a comprehensive assessment of local and regional radiographic parameters following MI-TLIF and open TLIF. The authors hypothesized that open TLIF provides greater segmental and global lordosis correction than MI-TLIF., Methods: A single-center retrospective cohort study of consecutive patients undergoing MI- or open TLIF for grade I degenerative spondylolisthesis was performed. One-to-one nearest-neighbor propensity score matching (PSM) was used to match patients who underwent open TLIF to those who underwent MI-TLIF. Sagittal segmental radiographic measures included segmental lordosis (SL), anterior disc height (ADH), posterior disc height (PDH), foraminal height (FH), percent spondylolisthesis, and cage position. Lumbopelvic radiographic parameters included overall lumbar lordosis (LL), pelvic incidence (PI)-lumbar lordosis (PI-LL) mismatch, sacral slope (SS), and pelvic tilt (PT). Change in segmental or overall lordosis after surgery was considered "lordosing" if the change was > 0° and "kyphosing" if it was ≤ 0°. Student t-tests or Wilcoxon rank-sum tests were used to compare outcomes between MI-TLIF and open-TLIF groups., Results: A total of 267 patients were included in the study, 114 (43%) who underwent MI-TLIF and 153 (57%) who underwent open TLIF, with an average follow-up of 56.6 weeks (SD 23.5 weeks). After PSM, there were 75 patients in each group. At the latest follow-up both MI- and open-TLIF patients experienced significant improvements in assessment scores obtained with the Oswestry Disability Index (ODI) and the numeric rating scale for low-back pain (NRS-BP), without significant differences between groups (p > 0.05). Both MI- and open-TLIF patients experienced significant improvements in SL, ADH, and percent corrected spondylolisthesis compared to baseline (p < 0.001). However, the MI-TLIF group experienced significantly larger magnitudes of correction with respect to these metrics (ΔSL 4.14° ± 4.35° vs 1.15° ± 3.88°, p < 0.001; ΔADH 4.25 ± 3.68 vs 1.41 ± 3.77 mm, p < 0.001; percent corrected spondylolisthesis: -10.82% ± 6.47% vs -5.87% ± 8.32%, p < 0.001). In the MI-TLIF group, LL improved in 44% (0.3° ± 8.5°) of the cases, compared to 48% (0.9° ± 6.4°) of the cases in the open-TLIF group (p > 0.05). Stratification by operative technique (unilateral vs bilateral facetectomy) and by interbody device (static vs expandable) did not yield statistically significant differences (p > 0.05)., Conclusions: Both MI- and open-TLIF patients experienced significant improvements in patient-reported outcome (PRO) measures and local radiographic parameters, with neutral effects on regional alignment. Surprisingly, in our cohort, change in SL was significantly greater in MI-TLIF patients, perhaps reflecting the effect of operative techniques, technological innovations, and the preservation of the posterior tension band. Taking these results together, no significant overall differences in LL between groups were demonstrated, which suggests that MI-TLIF is comparable to open approaches in providing radiographic correction after surgery. These findings suggest that alignment targets can be achieved by either MI- or open-TLIF approaches, highlighting the importance of surgeon attention to these variables.

Background Context: There is growing interest among payers in profiling hospital value and quality-of-care, including both the cost and safety of common surgeries, such as lumbar fusion. Nonetheless, there is sparse evidence describing the statistical reliability of such measures when applied to lumbar fusion for spondylolisthesis., Purpose: To evaluate the reliability of 90-day inpatient hospital costs, overall complications, and rates of serious complications for profiling hospital performance in lumbar fusion surgery for spondylolisthesis., Study Design/setting: Data for this analysis came from State Inpatient Databases from nine states made available through the Healthcare Cost and Utilization Project., Patient Sample: Patients undergoing elective lumbar spine fusion for spondylolisthesis from 2010 to 2017 in participating states., Outcome Measures: Statistical reliability, defined as the ability to distinguish true performance differences across hospitals relative to statistical noise. Reliability was assessed separately for 90-day inpatient costs (standardized across years to 2019 dollars), overall complications, and serious complication rates., Methods: Statistical reliability was measured as the amount of variation between hospitals relative to the total amount of variation for each measure. Total variation includes both between-hospital variation ("signal") and within-hospital variation ("statistical noise"). Thus, reliability equals signal over (signal plus noise) and ranges from 0 to 1. To adjust for differences in patient-level risk and procedural characteristics, hierarchical linear and logistic regression models were created for the cost and complication outcomes. Random hospital intercepts were used to assess between-hospital variation. We evaluated the reliability of each measure by study year and examined the number of hospitals meeting different thresholds of reliability by year., Results: We included a total of 66,571 elective lumbar fusion surgeries for spondylolisthesis performed at 244 hospitals during the study period. The mean 90-day hospital cost was $30,827 (2019 dollars). 12.0% of patients experienced a complication within 90 days of surgery, including 7.8% who had a serious complication. The median reliability of 90-day cost ranged from 0.97to 0.99 across study years, and there was a narrow distribution of reliability values. By comparison, the median reliability for the overall complication metric ranged from 0.22 to 0.44, and the reliability of the serious complication measure ranged from 0.30 to 0.49 across the study years. At least 96% of hospitals had high (> 0.7) reliability for cost in any year, whereas only 0-9% and 0-11% of hospitals reached this cutoff for the overall and serious complication rate in any year, respectively. By comparison, 10%-69% of hospitals per year achieved a more moderate threshold of 0.4 reliability for overall complications, compared to 21%-80% of hospitals who achieved this lower reliability threshold for serious complications., Conclusions: 90-day inpatient costs are highly reliable for assessing variation across hospitals, whereas overall and serious complications are only moderately reliable for profiling performance. These results support the viability of emerging bundled payment programs that assume true differences in costs of care exist across hospitals., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: Minimally invasive surgery (MIS) techniques can effectively stabilize and decompress many thoracolumbar injuries with decreased morbidity and tissue destruction compared with open approaches. Nonetheless, there is limited direction regarding the breadth and limitations of MIS techniques for thoracolumbar injuries. Consequently, the objectives of this study were to 1) identify the range of current practice patterns for thoracolumbar trauma and 2) integrate expert opinion and literature review to develop an updated treatment algorithm., Methods: A survey describing 10 clinical cases with a range of thoracolumbar injuries was sent to 12 surgeons with expertise in spine trauma. The survey results were summarized using descriptive statistics, along with the Fleiss kappa statistic of interrater agreement. To develop an updated treatment algorithm, the authors used a modified Delphi technique that incorporated a literature review, the survey results, and iterative feedback from a group of 14 spine trauma experts. The final algorithm represented the consensus opinion of that expert group., Results: Eleven of 12 surgeons contacted completed the case survey, including 8 (73%) neurosurgeons and 3 (27%) orthopedic surgeons. For the 4 cases involving patients with neurological deficits, nearly all respondents recommended decompression and fusion, and the proportion recommending open surgery ranged from 55% to 100% by case. Recommendations for the remaining cases were heterogeneous. Among the neurologically intact patients, MIS techniques were typically recommended more often than open techniques. The overall interrater agreement in recommendations was 0.23, indicating fair agreement. Considering both literature review and expert opinion, the updated algorithm indicated that MIS techniques could be used to treat most thoracolumbar injuries. Among neurologically intact patients, percutaneous instrumentation without arthrodesis was recommended for those with AO Spine Thoracolumbar Classification System subtype A3/A4 (Thoracolumbar Injury Classification and Severity Score [TLICS] 4) injuries, but MIS posterior arthrodesis was recommended for most patients with AO Spine subtype B2/B3 (TLICS > 4) injuries. Depending on vertebral body integrity, anterolateral corpectomy or mini-open decompression could be used for patients with neurological deficits., Conclusions: Spine trauma experts endorsed a range of strategies for treating thoracolumbar injuries but felt that MIS techniques were an option for most patients. The updated treatment algorithm may provide a foundation for surgeons interested in safe approaches for using MIS techniques to treat thoracolumbar trauma.

Objective: Nerve transfers are increasingly being utilized in the treatment of chronic tetraplegia, with increasing literature describing significant improvements in sensorimotor function up to years after injury. However, despite technical advances, clinical outcomes remain heterogenous. Preoperative electrodiagnostic testing is the most direct measure of nerve health and may provide prognostic information that can optimize preoperative patient selection. The objective of this study in patients with spinal cord injury (SCI) was to determine various zones of injury (ZOIs) via electrodiagnostic assessment (EDX) to predict motor outcomes after nerve transfers in tetraplegia., Methods: This retrospective review of prospectively collected data included all patients with tetraplegia from cervical SCI who underwent nerve transfer at the authors' institution between 2013 and 2020. Preoperative demographic data, results of EDX, operative details, and postoperative motor outcomes were extracted. EDX was standardized into grades that describe donor and recipient nerves. Five zones of SCI were defined. Motor outcomes were then compared based on various zones of innervation., Results: Nineteen tetraplegic patients were identified who underwent 52 nerve transfers targeting hand function, and 75% of these nerve transfers were performed more than 1 year postinjury, with a median interval to surgery following SCI of 24 (range 8-142) months. Normal recipient compound muscle action potential and isolated upper motor neuron injury on electromyography (EMG) were associated with greater motor recovery. When nerve transfers were stratified based on donor EMG, greater motor gains were associated with normal than with abnormal donor EMG motor unit recruitment patterns. When nerve transfers were separated based on donor and recipient nerves, normal flexor donors were more crucial than normal extensor donors in powering their respective flexor recipients., Conclusions: This study elucidates the relationship of the preoperative innervation zones in SCI patients to final motor outcomes. EDX studies can be used to tailor surgical therapies for nerve transfers in patients with tetraplegia. The authors propose an algorithm for optimizing nerve transfer strategies in tetraplegia, whereby understanding the ZOI and grade of the donor/recipient nerve is critical to predicting motor outcomes.

Study Design: This was a retrospective clinical series., Objective: The objective of this study was to evaluate radiologic changes in central spinal canal dimensions following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) with placement of a static or an expandable interbody device., Summary of Background Data: MIS-TLIF is used to treat lumbar degenerative diseases and low-grade spondylolisthesis. MIS-TLIF enables direct and indirect decompression of lumbar spinal stenosis, with patients experiencing relief from radiculopathy and neurogenic claudication. However, the effects of MIS-TLIF on the central spinal canal are not well-characterized., Materials and Methods: We identified patients who underwent MIS-TLIF for degenerative lumbar spondylolisthesis and concurrent moderate to severe spinal stenosis. We selected patients who had both preoperative and postoperative magnetic resonance imaging (MRI) and upright lateral radiographs of the lumbar spine. Measurements on axial T2-weighted MRI scans include anteroposterior and transverse dimensions of the dural sac and osseous spinal canal. Measurements on radiographs include disk height, neural foraminal height, segmental lordosis, and spondylolisthesis. We made pairwise comparisons between each of the central canal dimensions and lumbar sagittal segmental radiologic outcome measures relative to their corresponding preoperative values. Correlation coefficients were used to quantify the association between changes in lumbar sagittal segmental parameters relative to changes in radiologic outcomes of central canal dimensions. Statistical analysis was performed for "all patients" and further stratified by interbody device subgroups (static and expandable)., Results: Fifty-one patients (age 60.4 y, 68.6% female) who underwent MIS-TLIF at 55 levels (65.5% at L4-L5) were included in the analysis. Expandable interbody devices were used in 45/55 (81.8%) levels. Mean duration from surgery to postoperative MRI scan was 16.5 months (SD 11.9). MIS-TLIF was associated with significant improvements in dural sac dimensions (anteroposterior +0.31 cm, transverse +0.38 cm) and osseous spinal canal dimensions (anteroposterior +0.16 cm, transverse +0.32 cm). Sagittal lumbar segmental parameters of disk height (+0.56 cm), neural foraminal height (+0.35 cm), segmental lordosis (+4.26 degrees), and spondylolisthesis (-7.5%) were also improved following MIS-TLIF. We did not find meaningful associations between the changes in central canal dimensions relative to the corresponding changes in any of the sagittal lumbar segmental parameters. Stratified analysis by interbody device type (static and expandable) revealed similar within-group changes as in the overall cohort and minimal between-group differences., Conclusions: MIS-TLIF is associated with radiologic decompression of neural foraminal and central spinal canal stenosis. The mechanism for neural foraminal and central canal decompression is likely driven by a combination of direct and indirect corrective techniques., Competing Interests: W.Z.R.: is a consultant with Depuy/Synthes and Globus Spine and has received non–study-related research support from the Department of Defense, National Institutes of Health, Defense Advanced Research Projects Agency. I.G.D.: is a consultant with Medtronic and Stryker. D.J.: is an advisor for Kaia Health. V.C.: is a consultant with DePuy Synthes and Globus Medical and has received non–study-related research support from Medtronic. The remaining authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: Retrospective analysis of administrative billing data., Objective: To evaluate the extent to which a metric of serious complications determined from administrative data can reliably profile hospital performance in spine fusion surgery., Summary of Background Data: While payers are increasingly focused on implementing pay-for-performance measures, quality metrics must reliably reflect true differences in performance among the hospitals profiled., Methods: We used State Inpatient Databases from nine states to characterize serious complications after elective cervical and thoracolumbar fusion. Hierarchical logistic regression was used to risk-adjust differences in case mix, along with variability from low case volumes. The reliability of this risk-stratified complication rate (RSCR) was assessed as the variation between hospitals that was not due to chance alone, calculated separately by fusion type and year. Finally, we estimated the proportion of hospitals that had sufficient case volumes to obtain reliable (>0.7) complication estimates., Results: From 2010 to 2017 we identified 154,078 cervical and 213,133 thoracolumbar fusion surgeries. 4.2% of cervical fusion patients had a serious complication, and the median RSCR increased from 4.2% in 2010 to 5.5% in 2017. The reliability of the RSCR for cervical fusion was poor and varied substantially by year (range 0.04-0.28). Overall, 7.7% of thoracolumbar fusion patients experienced a serious complication, and the RSCR varied from 6.8% to 8.0% during the study period. Although still modest, the RSCR reliability was higher for thoracolumbar fusion (range 0.16-0.43). Depending on the study year, 0% to 4.5% of hospitals had sufficient cervical fusion case volume to report reliable (>0.7) estimates, whereas 15% to 36% of hospitals reached this threshold for thoracolumbar fusion., Conclusion: A metric of serious complications was unreliable for benchmarking cervical fusion outcomes and only modestly reliable for thoracolumbar fusion. When assessed using administrative datasets, these measures appear inappropriate for high-stakes applications, such as public reporting or pay-for-performance.Level of Evidence: 3., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

En bloc spinal tumor resections are technically demanding procedures with high morbidity because of the conventionally large exposure area and aggressive resection goals. Stereotactic surgical navigation presents an opportunity to perform the smallest possible resection plan while still achieving an en bloc resection. Augmented reality (AR)-mediated spine surgery (ARMSS) via a mounted display with an integrated tracking camera is a novel FDA-approved technology for intraoperative "heads up" neuronavigation, with the proposed advantages of increased precision, workflow efficiency, and cost-effectiveness. As surgical experience and capability with this technology grow, the potential for more technically demanding surgical applications arises. Here, the authors describe the use of ARMSS for guidance in a unique osteotomy execution to achieve an en bloc wide marginal resection of an L1 chordoma through a posterior-only approach while avoiding a tumor capsule breach. A technique is described to simultaneously visualize the navigational guidance provided by the contralateral surgeon's tracked pointer and the progress of the BoneScalpel aligned in parallel with the tracked instrument, providing maximum precision and safety. The procedure was completed by reconstruction performed with a quad-rod and cabled fibular strut allograft construct, and the patient did well postoperatively. Finally, the authors review the technical aspects of the approach, as well as the applications and limitations of this new technology.

Objective: The aim of this study was to examine the role of intraoperative neuromonitoring (IONM) during resection of benign peripheral nerve sheath tumors in achieving gross-total resection (GTR) and in reducing postoperative neurological complications., Methods: Data from consecutive adult patients who underwent resection of a benign peripheral nerve sheath tumor at 7 participating institutions were combined. Propensity score matching was used to balance covariates. The primary outcomes of interest were the association between IONM and GTR and the association of IONM and the development of a permanent postoperative neurological complication. The secondary outcomes of interest were the association between IONM and GTR and the association between IONM and the development of a permanent postoperative neurological complication in the subgroup of patients with tumors involving a motor or mixed nerve. Univariate and multivariate logistic regression were then performed on the propensity score-matched samples to assess the ability of the independent variables to predict the outcomes of interest., Results: A total of 337 patients who underwent resection of benign nerve sheath tumors were included. In multivariate analysis, the use of IONM (OR 0.460, 95% CI 0.199-0.978; p = 0.047) was a significant negative predictor of GTR, whereas none of the variables, including IONM, were associated with the occurrence of a permanent postoperative neurological complication. Within the subgroup of motor/mixed nerve tumors, in the multivariate analysis, IONM (OR 0.263, 95% CI 0.096-0.723; p = 0.010) was a significant negative predictor of a GTR, whereas IONM (OR 3.800, 95% CI 1.925-7.502; p < 0.001) was a significant positive predictor of a permanent postoperative motor deficit., Conclusions: Overall, 12% of the cohort had a permanent neurological complication, with new or worsened paresthesias most common, followed by pain and then weakness. The authors found that formal IONM was associated with a reduced likelihood of GTR and had no association with neurological complications. The authors believe that these data argue against IONM being considered standard of care but do not believe that these data should be used to universally argue against IONM during resection of benign nerve sheath tumors.

Introduction : The field of augmented reality mediated spine surgery is growing rapidly and holds great promise for improving surgical capabilities and patient outcomes. Augmented reality can assist with complex or atypical cases involving challenging anatomy. As neuronavigation evolves, fundamental technical limitations remain in line-of-sight interruption and operator attention shift, which this novel augmented reality technology helps to address. Areas covered : XVision is a recently FDA-approved head mounted display for intraoperative neuronavigation, compatible with all current conventional pedicle screw technology. The device is a wireless, customizable headset with an integrated surgical tracking system and transparent retinal display. This review discusses the available literature on the safety and efficacy of XVision, as well as the current state of augmented reality technology in spine surgery. Expert opinion : Augmented-reality spine surgery is an emerging technology that may increase precision, efficiency, and safety as well as decrease radiation exposure of manual and robotic computer-navigated pedicle screw insertion techniques. The initial clinical experience with XVision has shown good outcomes and it has received positive operator feedback. Now that initial clinical safety and efficacy has been demonstrated, ongoing experience must be studied to empirically validate this technology and generate further innovation in this rapidly evolving field.

Background: Advances in operative techniques and minimally invasive technologies have evolved to maximize patient outcomes and radiographic results, while reducing morbidity and recovery time., Objective: To describe the operative technique for a transfacet minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) as a proposed modification to the standard approach MIS-TLIF., Methods: We present the case of a 72-yr-old man with left-sided lumbar radiculopathy. Preoperative imaging demonstrated degenerative lumbar anterolisthesis at L4-5, with associated canal and neuroforaminal stenosis. The patient underwent transfacet MIS-TLIF at L4-L5. We describe the preoperative planning, patient positioning, incision and dissection, pedicle screw insertion, transfacet approach to the working access corridor, discectomy, interbody device placement, fixation, and closure., Results: The transfacet MIS-TLIF utilizes 3 key techniques to safely maximize surgical correction: (1) a limited bony resection based on the superior articular process, leaving the medial inferior articular process, lateral superior articular process, and rostral pars intact, providing a working bony corridor that protects the traversing and exiting nerve roots; (2) decortication and release of the contralateral facet joint to provide additional capacity for indirect decompression and provide the first point of osseous fusion; and (3) placement of an expandable interbody device that provides additional indirect decompression to the working side and contralateral foramen., Conclusion: The transfacet MIS-TLIF uniquely leverages a bony working corridor to access the disc space for discectomy and interbody placement. Transfacet MIS-TLIF is a feasible solution for lumbar spinal reconstruction to maximize direct and indirect decompression of the neuroforamina and central spinal canal in patients with lumbar degenerative diseases and low-grade spondylolisthesis., (Copyright © 2020 by the Congress of Neurological Surgeons.)

Background: Advances in operative techniques and instrumentation technology have evolved to maximize patient outcomes following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). The transfacet MIS-TLIF is a modified approach to the standard MIS-TLIF that leverages a bony working corridor to access the disc space for discectomy and interbody device placement., Objective: To evaluate clinical and radiographic results following transfacet MIS-TLIF using an expandable interbody device., Methods: We performed a retrospective review of consecutive patients who underwent transfacet MIS-TLIF for degenerative lumbar spondylolisthesis. Patient-reported outcome measures for pain and disability were assessed. Sagittal lumbar segmental parameters and regional lumbopelvic parameters were assessed on upright lateral radiographs obtained preoperatively and during follow-up., Results: A total of 68 patients (61.8% male) underwent transfacet MIS-TLIF at 74 levels. The mean age was 63.4 yr and the mean follow-up 15.2 mo. Patients experienced significant short- and long-term postoperative improvements on the numeric rating scale for low back pain (-2.3/10) and Oswestry Disability Index (-12.0/50). Transfacet MIS-TLIF was associated with an immediate and sustained reduction of spondylolisthesis, and an increase in index-level disc height (+0.71 cm), foraminal height (+0.28 cm), and segmental lordosis (+6.83°). Patients with preoperative hypolordosis (<40°) experienced significant increases in segmental (+9.10°) and overall lumbar lordosis (+8.65°). Pelvic parameters were not significantly changed, regardless of preoperative alignment. Device subsidence was observed in 6/74 (8.1%) levels, and fusion in 50/53 (94.3%) levels after 12 mo., Conclusion: Transfacet MIS-TLIF was associated with clinical improvements and restoration of radiographic sagittal segmental parameters. Regional alignment correction was observed among patients with hypolordosis at baseline., (Copyright © 2020 by the Congress of Neurological Surgeons.)

Background: Tetraplegia caused by cervical spinal cord injury is devastating for patients and represents a significant public health problem in both developed and developing countries. Improved functional outcomes after nerve transfers are increasingly reported in the literature, but thus far, no options exist for injuries above the C5 level., Case Description: We report the cases of 2 patients with C4 spinal cord injury, American Spinal Injury Association A, who underwent successful bilateral spinal accessory nerve transfers, on 1 side to the triceps nerve with long intervening sural graft and on the other side direct transfer to the motor fascicles of the middle trunk. Patients improved from Medical Research Council 0 to 4 on the side of the nerve graft and 0 to 2 or 3 on the side of the direct transfer. Both patients also underwent transfer of the greater auricular nerve to sensory fascicles of the middle trunk, and they experienced sensory recovery in the C6 distribution. Notably, both patients were far removed from the traditional window of nerve transfer surgery at 4 years and almost 11 years out from injury., Conclusions: We describe 2 successful cases of the first and to date only option for motor and sensory reinnervation in high cervical spinal cord injuries. These procedures provide a robust nerve transfer option capable of improving quality of life in tetraplegic patients. There may be a significant undertreated population of patients with cervical spinal cord injury patients in the United States who were previously considered outside the window for benefiting from nerve transfers but who would benefit from these techniques., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: Patients with cervical spinal cord injury (SCI)/tetraplegia consistently rank restoring arm and hand function as their top functional priority to improve quality of life. Motor nerve transfers traditionally used to treat peripheral nerve injuries are increasingly being used to treat patients with cervical SCIs. In this study, the authors performed a systematic review summarizing the published literature on nerve transfers to restore upper-extremity function in tetraplegia., Methods: A systematic literature search was conducted using Ovid MEDLINE 1946-, Embase 1947-, Scopus 1960-, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and clinicaltrials.gov to identify relevant literature published through January 2019. The authors included studies that provided original patient-level data and extracted information on clinical characteristics, operative details, and strength outcomes after nerve transfer procedures. Critical review and synthesis of the articles were performed., Results: Twenty-two unique studies, reporting on 158 nerve transfers in 118 upper limbs of 92 patients (87 males, 94.6%) were included in the systematic review. The mean duration from SCI to nerve transfer surgery was 18.7 months (range 4 months-13 years) and mean postoperative follow-up duration was 19.5 months (range 1 month-4 years). The main goals of reinnervation were the restoration of thumb and finger flexion, elbow extension, and wrist and finger extension. Significant heterogeneity in transfer strategy and postoperative outcomes were noted among the reports. All but one case report demonstrated recovery of at least Medical Research Council grade 3/5 strength in recipient muscle groups; however, there was greater variation in the results of larger case series. The best, most consistent outcomes were demonstrated for restoration of wrist/finger extension and elbow extension., Conclusions: Motor nerve transfers are a promising treatment option to restore upper-extremity function after SCI. Flexor reinnervation strategies show variable treatment effect sizes; however, extensor reinnervation may provide more consistent, meaningful recovery. Despite numerous published case reports describing good patient outcomes with nerve transfers, there remains a paucity in the literature regarding optimal timing and long-term clinical outcomes with these procedures.

Objective: Patients with cervical spinal cord injury (SCI)/tetraplegia consistently rank restoring arm and hand function as their top functional priority to improve quality of life. Motor nerve transfers traditionally used to treat peripheral nerve injuries are increasingly used to treat patients with cervical SCIs. In this article, the authors present early results of a prospective clinical trial using nerve transfers to restore upper-extremity function in tetraplegia., Methods: Participants with American Spinal Injury Association (ASIA) grade A-C cervical SCI/tetraplegia were prospectively enrolled at a single institution, and nerve transfer(s) was performed to improve upper-extremity function. Functional recovery and strength outcomes were independently assessed and prospectively tracked., Results: Seventeen participants (94.1% males) with a median age of 28.4 years (range 18.2-76.3 years) who underwent nerve transfers at a median of 18.2 months (range 5.2-130.8 months) after injury were included in the analysis. Preoperative SCI levels ranged from C2 to C7, most commonly at C4 (35.3%). The median postoperative follow-up duration was 24.9 months (range 12.0-29.1 months). Patients who underwent transfers to median nerve motor branches and completed 18- and 24-month follow-ups achieved finger flexion strength Medical Research Council (MRC) grade ≥ 3/5 in 4 of 15 (26.7%) and 3 of 12 (25.0%) treated upper limbs, respectively. Similarly, patients achieved MRC grade ≥ 3/5 wrist flexion strength in 5 of 15 (33.3%) and 3 of 12 (25.0%) upper limbs. Among patients who underwent transfers to the posterior interosseous nerve (PIN) for wrist/finger extension, MRC grade ≥ 3/5 strength was demonstrated in 5 of 9 (55.6%) and 4 of 7 (57.1%) upper limbs 18 and 24 months postoperatively, respectively. Similarly, grade ≥ 3/5 strength was demonstrated in 5 of 9 (55.6%) and 4 of 7 (57.1%) cases for thumb extension. No meaningful donor site deficits were observed. Patients reported significant postoperative improvements from baseline on upper-extremity-specific self-reported outcome measures., Conclusions: Motor nerve transfers are a promising treatment option to restore upper-extremity function after SCI. In the authors' experience, nerve transfers for the reinnervation of hand and finger flexors showed variable functional recovery; however, transfers for the reinnervation of arm, hand, and finger extensors showed a more consistent and meaningful return of strength and function.

Objective: The Patient-Reported Outcomes Measurement Information System (PROMIS) is an adaptive, self-reported outcomes assessment tool that utilizes item response theory and computer adaptive testing to efficiently and precisely evaluate symptoms and perceived health status. Efforts to implement and report PROMIS outcomes in spine clinical practice remain limited. The objective of this retrospective cohort study is to evaluate the performance and psychometric properties of PROMIS physical function (PF) and pain interference (PI) among patients undergoing spine surgery., Methods: The authors identified all patients who underwent spine surgery at their institution between 2016 and 2018, and for whom there was retrievable PROMIS data. Descriptive statistics were calculated to summarize demographics, operative characteristics, and patient-reported outcomes. Assessments were evaluated preoperatively, and postoperatively within 2 months (early), 6 months (intermediate), and up to 2 years (late). Pairwise change scores were calculated to evaluate within-subjects differences and construct responsiveness over time. Pearson's correlation coefficients were used to evaluate the association between PROMIS PF and PI domains. Subgroup analysis was performed based on the primary diagnoses of cervical radiculopathy, cervical myelopathy, or lumbar degenerative disease., Results: A total of 2770 patients (1395 males, 50.4%) were included in the analysis. The mean age at the time of surgery was 57.3 ± 14.4 years. Mean postoperative follow-up duration was 7.6 ± 6.2 months. Preoperatively, patients scored an average 15.1 ± 7.4 points below the normative population (mean 50 ± 10 points) in PF, and 15.8 ± 6.8 points above the mean in PI. PROMIS PF required a mean of 4.1 ± 0.6 questions and median 40 seconds (interquartile range [IQR] 29-58 seconds) to be completed, which was similar to PI (median 4.3 ± 1.1 questions and 38 seconds [IQR 27-59 seconds]). Patients experienced clinically meaningful improvements in PF and PI, which were sustained throughout the postoperative course. PROMIS instruments were able to capture anticipated changes in PF and PI, although to a lesser degree in PF early postoperatively. There was a strong negative correlation between PROMIS PF and PI scores at baseline (Pearson's r = -0.72) and during follow-up appointments (early, intermediate, and late |r| > 0.6, each). Subgroup analysis demonstrated similar results within diagnostic groups compared to the overall cohort. However, the burden of PF limitations and PI was greater within the lumbar spine disease subgroup, compared to patients with cervical radiculopathy and myelopathy., Conclusions: Patients receiving care at a tertiary spine surgery outpatient clinic experience significant overall disability and PI, as measured by PROMIS PF and PI computer adaptive tests. PROMIS PF and PI health domains are strongly correlated, responsive to changes over time, and facilitate time-efficient evaluations of perceived health status outcomes in patients undergoing spine surgery.

Background: Restoration of shoulder function is an important treatment goal in upper brachial plexus injury (UBPI). Combined dual motor nerve transfer (CDNT) of spinal accessory to suprascapular and radial to axillary nerves demonstrates good functional recovery with minimal risk of perioperative complications., Objective: To evaluate the cost-effectiveness of CDNT vs alternative operative and nonoperative treatments for UBPI., Methods: A decision model was constructed to evaluate costs ($, third-party payer) and effectiveness (quality-adjusted life years [QALYs]) of CDNT compared to glenohumeral arthrodesis (GA), conservative management, and nontreatment strategies. Estimates for branch probabilities, costs, and QALYs were derived from published studies. Incremental cost-effectiveness ratios (ICER, $/QALY) were calculated to compare the competing strategies. One-way, 2-way, and probabilistic sensitivity analyses with 100 000 iterations were performed to account for effects of uncertainty in model inputs., Results: Base case model demonstrated CDNT effectiveness, yielding an expected 21.04 lifetime QALYs, compared to 20.89 QALYs with GA, 19.68 QALYs with conservative management, and 19.15 QALYs with no treatment. The ICERs for CDNT, GA, and conservative management vs nontreatment were $5776.73/QALY, $10 483.52/QALY, and $882.47/QALY, respectively. Adjusting for potential income associated with increased likelihood of returning to work after clinical recovery demonstrated CDNT as the dominant strategy, with ICER = -$56 459.54/QALY relative to nontreatment. Probabilistic sensitivity analysis showed CDNT cost-effectiveness at a willingness-to-pay threshold of $50 000/QALY in 78.47% and 81.97% of trials with and without income adjustment, respectively. Conservative management dominated in <1% of iterations., Conclusion: CDNT and GA are cost-effective interventions to restore shoulder function in patients with UBPI.

AVMs are congenital lesions that predispose patients to intracranial hemorrhage and resultant neurological deficits. These deficits are often focal and due to the presence of local neurologic disruption from hemorrhage in the contralateral cerebral hemisphere. We present a rare case of a patient with ipsilateral neurological deficits due to Kernohan's Notch phenomenon resulting from hemorrhage from an AVM. A 31-year-old woman with seizures underwent MR and angiographic imaging which confirmed an unruptured left parietal AVM. The patient declined treatment and presented with obtundation 4 years later. Imaging revealed an acute left parietal ICH and SDH with significant mass effect. The patient underwent emergent hemicraniectomy and hematoma evacuation. Postoperatively, she made significant improvement and was following commands contralaterally with ipsilateral hemiplegia. MR imaging revealed right Kernohan's Notch. The patient had significant rehabilitation with neurological improvement. She eventually underwent elective embolization followed by subsequent surgical resection and bone replacement. Three years from the initial hemorrhage, the patient had only mild left-sided weakness and ambulates without assistance. A false localizing sign, Kernohan's Notch phenomenon, should be considered in the setting of AVM hemorrhage with paradoxical motor impairment and can be identified through MRI.

Three genetic mutations were found to cause cerebral cavernous malformation (CCM), a vascular anomaly predisposing affected individuals to hemorrhagic stroke. These CCM proteins function together as a protein complex in the cell. Loss of expression of each CCM gene results in loss of in vitro endothelial tube formation. Label-free differential protein expression analysis using multidimensional liquid chromatography/tandem mass spectrometry (2D-LC-MS/MS) was applied to explore the proteomic profile for loss of each CCM gene expression in mouse endothelial stem cells (MEES) compared to mock shRNA and no shRNA control cell-lines. Differentially expressed proteins were identified (p < 0.05). 120 proteins were differentially expressed among the cell-lines. Principal component analysis and cluster analysis show the effects of individual knockdown. In all knockdown cell-lines, altered expression of cytoskeletal proteins is the most common. While all CCM mutations result in similar pathology, different CCM mutations have their own distinct pathogenesis in cell signaling.

Unlabelled: Cerebral cavernous malformations (CCM) are vascular anomalies caused by mutations in genes encoding KRIT1, OSM and PDCD10 proteins causing hemorrhagic stroke. We examine proteomic change of loss of CCM gene expression. Using human umbilical vein endothelial cells, label-free differential protein expression analysis with multidimensional liquid chromatography/tandem mass spectrometry was applied to three CCM protein knockdown cell lines and two control cell lines: ProteomeXchange identifier PXD000362. Principle component and cluster analyses were used to examine the differentially expressed proteins associated with CCM. The results from the five cell lines revealed 290 and 192 differentially expressed proteins (p < 0.005 and p < 0.001, respectively). Most commonly affected proteins were cytoskeleton-associated proteins, in particular myosin-9. Canonical genetic pathway analysis suggests that CCM may be a result of defective cell-cell interaction through dysregulation of cytoskeletal associated proteins., Conclusion: The work explores signaling pathways that may elucidate early detection and novel therapy for CCM.

Autosomal dominant mutations in PTH1R segregate with primary failure of eruption (PFE), marked by clinical eruption failure of adult teeth without mechanical obstruction. While the diagnosis of PFE conveys a poor dental prognosis, there are no reports of PFE patients who carry PTH1R mutations and exhibit any other skeletal problems. We performed polymerase chain reaction-based mutational analysis of the PTH1R gene to determine the genetic contribution of PTH1R in 10 families with PFE. Sequence analysis of the coding regions and intron-exon boundaries of the PTH1R gene in 10 families (n = 54) and 7 isolated individuals revealed 2 novel autosomal dominant mutations in PTH1R (c.996&#95;997insC and C.572delA) that occur in the coding region and result in a truncated protein. One family showed incomplete penetrance. Of 10 families diagnosed with PFE, 8 did not reveal functional (nonsynonymous) mutations in PTH1R; furthermore, 4 families and 1 sporadic case carried synonymous single-nucleotide polymorphisms. Five PFE patients in 2 families carried PTH1R mutations and presented with osteoarthritis. We propose that the autosomal dominant mutations of PTH1R that cause PFE may also be associated with osteoarthritis; a dose-dependent model may explain isolated PFE and osteoarthritis in the absence of other known symptoms in the skeletal system.

Cerebral cavernous malformation (CCM) involves the homozygous inactivating mutations of one of three genes, ccm1, -2, or -3 resulting in hyperpermeable blood vessels in the brain. The CCM1, -2, and -3 proteins form a complex to organize the signaling networks controlling endothelial cell physiology including actin dynamics, tube formation, and adherens junctions. The common biochemical defect with the loss of CCM1, -2, or -3 is increased RhoA activity leading to the activation of Rho-associated coiled coil-forming kinase (ROCK). Inhibition of the ROCK rescues CCM endothelial cell dysfunction, suggesting that the inhibition of RhoA-ROCK signaling may be a therapeutic strategy to prevent or arrest the progression of the CCM lesions.

Denture stomatitis (DS) is the most common oral pathology among denture wearers, affecting over one-third of this group. DS is usually associated with C. albicans. However, unlike other oral candidiasis, most DS patients have intact host immunity. The presence of a denture alone is usually sufficient for DS. Saliva and its protein contents can theoretically predispose some denture wearers to DS and others resistant toward DS. Here we proposed for the first time to define salivary proteomic profiles of denture wearers with and without DS. SELDI-TOF/MS analysis suggests that there is a proteomic differentiation among control, localized and generalized DS. Based on initial SELDI-TOF/MS profiling, we further used reversed phase liquid chromatography, MALDI-TOF/MS, and LC-MS/MS to characterize the salivary proteins associated with DS. Nineteen proteins based on SELDI-TOF/MS profiling were found including cystatin-SN, statherin, kininogen-1, desmocollin-2, carbonic anhydrase-6, peptidyl-prolyl cis-trans isomerase A like peptides, cystatin C, and several immunoglobulin fragments. The proteomic content gives evidence of the interaction between host tissue, saliva, and candida. Further examination in larger populations of these proteins may help to gain a better understanding of DS pathological processes and improve DS treatments.

Type 2 diabetes and tooth loss are linked both epidemiologically and pathophysiologically. We applied label-free differential protein expression analysis using multidimensional liquid chromatography/tandem mass spectrometry (2D-LC-MS/MS) to explore the proteomic profile of saliva samples collected from selected type 2 diabetic edentulous patients and non-diabetic controls. Ninety-six peptides corresponding to 52 proteins were differentially expressed between the diabetic edentulous patients and controls (p < 0.05). Some diabetes-related inflammatory biomarkers including glyceraldehyde-3-phosphate dehydrogenase and serum amyloid A were detected with levels increased in diabetic samples. Other biomarkers including amylase, palate, lung and nasal epithelium associated protein (PLUNC), and serotransferrin levels were decreased in diabetic samples. In contrast with previous findings, salivary carbonic anhydrase 6 and alpha-2 macroglobulin levels, however, were decreased in this diabetic patient population. Cluster analysis and principle component analysis demonstrated a differential pattern of protein biomarker expression between diabetic and control subjects. Western blot analysis was completed to confirm the relatively lower expression level of two biomarkers, including PLUNC and amylase in the diabetic group compared to control subjects. The presence of salivary biomarkers specific for diabetes in edentulous subjects mimics those in serum, especially those related to inflammatory/lipid metabolism. While this exploratory study requires further validation with a larger population, it provides proof-of-principle for salivary proteomics for edentulous subjects with diabetes.