Using Multimodal Assessments to Reevaluate Depression Designations for Spine Surgery Candidates.

BACKGROUND: Depression is common in spine surgery candidates and may influence postoperative outcomes. Ecological momentary assessments (EMAs) can overcome limitations of existing depression screening methods (e.g., recall bias, inaccuracy of historical diagnoses) by longitudinally monitoring depression symptoms in daily life. In this study, we compared EMA-based depression assessment with retrospective self-report (a 9-item Patient Health Questionnaire [PHQ-9]) and chart-based depression diagnosis in lumbar spine surgery candidates. We further examined the associations of each depression assessment method with surgical outcomes. METHODS: Adult patients undergoing lumbar spine surgery (n = 122) completed EMAs quantifying depressive symptoms up to 5 times daily for 3 weeks preoperatively. Correlations (rank-biserial or Spearman) among EMA means, a chart-based depression history, and 1-time preoperative depression surveys (PHQ-9 and Psychache Scale) were analyzed. Confirmatory factor analysis was used to categorize PHQ-9 questions as somatic or non-somatic; subscores were compared with a propensity score-matched general population cohort. The associations of each screening modality with 6-month surgical outcomes (pain, disability, physical function, pain interference) were analyzed with multivariable regression. RESULTS: The association between EMA Depression scores and a depression history was weak (rrb = 0.34 [95% confidence interval (CI), 0.14 to 0.52]). Moderate correlations with EMA-measured depression symptoms were observed for the PHQ-9 (rs = 0.51 [95% CI, 0.37 to 0.63]) and the Psychache Scale (rs = 0.68 [95% CI, 0.57 to 0.76]). Compared with the matched general population cohort, spine surgery candidates endorsed similar non-somatic symptoms but significantly greater somatic symptoms on the PHQ-9. EMA Depression scores had a stronger association with 6-month surgical outcomes than the other depression screening modalities did. CONCLUSIONS: A history of depression in the medical record is not a reliable indication of preoperative depression symptom severity. Cross-sectional depression assessments such as PHQ-9 have stronger associations with daily depression symptoms but may conflate somatic depression symptoms with spine-related disability. As an alternative to these methods, mobile health technology and EMAs provide an opportunity to collect real-time, longitudinal data on depression symptom severity, potentially improving prognostic accuracy. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Restoration of respiration in high cervical spinal cord injury via phrenic nerve reinnervation: illustrative case.

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.

Spinal cord metrics derived from diffusion MRI: improvement in prognostication in cervical spondylotic myelopathy compared with conventional MRI.

OBJECTIVE: A major shortcoming in optimizing care for patients with cervical spondylotic myelopathy (CSM) is the lack of robust quantitative imaging tools offered by conventional MRI. Advanced MRI modalities, such as diffusion MRI (dMRI), including diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI), may help address this limitation by providing granular evaluations of spinal cord microstructure. METHODS: Forty-seven patients with CSM underwent comprehensive clinical assessments and dMRI, followed by DTI and DBSI modeling. Conventional MRI metrics included 10 total qualitative and quantitative assessments of spinal cord compression in both the sagittal and axial planes. The dMRI metrics included 12 unique measures including anisotropic tensors, reflecting axonal diffusion, and isotropic tensors, describing extraaxonal diffusion. The primary outcome was the modified Japanese Orthopaedic Association (mJOA) score measured at 2 years postoperatively. Extreme gradient boosting-supervised classification algorithms were used to classify patients into disease groups and to prognosticate surgical outcomes at 2-year follow-up. RESULTS: Forty-seven patients with CSM, including 24 (51%) with a mild mJOA score, 12 (26%) with a moderate mJOA score, and 11 (23%) with a severe mJOA score, as well as 21 control subjects were included. In the classification task, the traditional MRI metrics correctly assigned patients to healthy control versus mild CSM versus moderate/severe CSM cohorts, with an accuracy of 0.647 (95% CI 0.64-0.65). In comparison, the DTI model performed with an accuracy of 0.52 (95% CI 0.51-0.52) and the DBSI model's accuracy was 0.81 (95% CI 0.808-0.814). In the prognostication task, the traditional MRI metrics correctly predicted patients with CSM who improved at 2-year follow-up on the basis of change in mJOA, with an accuracy of 0.58 (95% CI 0.57-0.58). In comparison, the DTI model performed with an accuracy of 0.62 (95% CI 0.61-0.62) and the DBSI model had an accuracy of 0.72 (95% CI 0.718-0.73). CONCLUSIONS: Conventional MRI is a powerful tool to assess structural abnormality in CSM but is inherently limited in its ability to characterize spinal cord tissue injury. The results of this study demonstrate that advanced imaging techniques, namely DBSI-derived metrics from dMRI, provide granular assessments of spinal cord microstructure that can offer better diagnostic and prognostic utility.

Clinical prediction for surgical versus nonsurgical interventions in patients with vertebral osteomyelitis and discitis.

Background: Vertebral osteomyelitis and discitis (VOD), an infection of intervertebral discs, often requires spine surgical intervention and timely management to prevent adverse outcomes. Our study aims to develop a machine learning (ML) model to predict the indication for surgical intervention (during the same hospital stay) versus nonsurgical management in patients with VOD. Methods: This retrospective study included adult patients (≥18 years) with VOD (ICD-10 diagnosis codes M46.2,3,4,5) treated at a single institution between 01/01/2015 and 12/31/2019. The primary outcome studied was surgery. Candidate predictors were age, sex, race, Elixhauser comorbidity index, first-recorded lab values, first-recorded vital signs, and admit diagnosis. After splitting the dataset, XGBoost, logistic regression, and K-neighbor classifier algorithms were trained and tested for model development. Results: A total of 1,111 patients were included in this study, among which 30% (n=339) of patients underwent surgical intervention. Age and sex did not significantly differ between the two groups; however, race did significantly differ (P<0.0001), with the surgical group having a higher percentage of white patients. The top ten model features for the best-performing model (XGBoost) were as follows (in descending order of importance): admit diagnosis of fever, negative culture, Staphylococcus aureus culture, partial pressure of arterial oxygen to fractional inspired oxygen ratio (PaO2:FiO2), admit diagnosis of intraspinal abscess and granuloma, admit diagnosis of sepsis, race, troponin I, acid-fast bacillus culture, and alveolar-arterial gradient (A-a gradient). XGBoost model metrics were as follows: accuracy =0.7534, sensitivity =0.7436, specificity =0.7586, and area under the curve (AUC) =0.8210. Conclusions: The XGBoost model reliably predicts the indication for surgical intervention based on several readily available patient demographic information and clinical features. The interpretability of a supervised ML model provides robust insight into patient outcomes. Furthermore, it paves the way for the development of an efficient hospital resource allocation instrument, designed to guide clinical suggestions.

Diffusion MRI Metrics Characterize Postoperative Clinical Outcomes After Surgery for Cervical Spondylotic Myelopathy.

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.

Preoperative Mobile Health Data Improve Predictions of Recovery From Lumbar Spine Surgery.

BACKGROUND AND OBJECTIVES: Neurosurgeons and hospitals devote tremendous resources to improving recovery from lumbar spine surgery. Current efforts to predict surgical recovery rely on one-time patient report and health record information. However, longitudinal mobile health (mHealth) assessments integrating symptom dynamics from ecological momentary assessment (EMA) and wearable biometric data may capture important influences on recovery. Our objective was to evaluate whether a preoperative mHealth assessment integrating EMA with Fitbit monitoring improved predictions of spine surgery recovery. METHODS: Patients age 21-85 years undergoing lumbar surgery for degenerative disease between 2021 and 2023 were recruited. For up to 3 weeks preoperatively, participants completed EMAs up to 5 times daily asking about momentary pain, disability, depression, and catastrophizing. At the same time, they were passively monitored using Fitbit trackers. Study outcomes were good/excellent recovery on the Quality of Recovery-15 (QOR-15) and a clinically important change in Patient-Reported Outcomes Measurement Information System Pain Interference 1 month postoperatively. After feature engineering, several machine learning prediction models were tested. Prediction performance was measured using the c-statistic. RESULTS: A total of 133 participants were included, with a median (IQR) age of 62 (53, 68) years, and 56% were female. The median (IQR) number of preoperative EMAs completed was 78 (61, 95), and the median (IQR) number of days with usable Fitbit data was 17 (12, 21). 63 patients (48%) achieved a clinically meaningful improvement in Patient-Reported Outcomes Measurement Information System pain interference. Compared with traditional evaluations alone, mHealth evaluations led to a 34% improvement in predictions for pain interference (c = 0.82 vs c = 0.61). 49 patients (40%) had a good or excellent recovery based on the QOR-15. Including preoperative mHealth data led to a 30% improvement in predictions of QOR-15 (c = 0.70 vs c = 0.54). CONCLUSION: Multimodal mHealth evaluations improve predictions of lumbar surgery outcomes. These methods may be useful for informing patient selection and perioperative recovery strategies.

Implications of Preoperative Depression for Lumbar Spine Surgery Outcomes: A Systematic Review and Meta-Analysis.

Importance: Comorbid depression is common among patients with degenerative lumbar spine disease. Although a well-researched topic, the evidence of the role of depression in spine surgery outcomes remains inconclusive. Objective: To investigate the association between preoperative depression and patient-reported outcome measures (PROMs) after lumbar spine surgery. Data Sources: A systematic search of PubMed, Cochrane Database of Systematic Reviews, Embase, Scopus, PsychInfo, Web of Science, and ClinicalTrials.gov was performed from database inception to September 14, 2023. Study Selection: Included studies involved adults undergoing lumbar spine surgery and compared PROMs in patients with vs those without depression. Studies evaluating the correlation between preoperative depression and disease severity were also included. Data Extraction and Synthesis: All data were independently extracted by 2 authors and independently verified by a third author. Study quality was assessed using Newcastle-Ottawa Scale. Random-effects meta-analysis was used to synthesize data, and I2 was used to assess heterogeneity. Metaregression was performed to identify factors explaining the heterogeneity. Main Outcomes and Measures: The primary outcome was the standardized mean difference (SMD) of change from preoperative baseline to postoperative follow-up in PROMs of disability, pain, and physical function for patients with vs without depression. Secondary outcomes were preoperative and postoperative differences in absolute disease severity for these 2 patient populations. Results: Of the 8459 articles identified, 44 were included in the analysis. These studies involved 21 452 patients with a mean (SD) age of 57 (8) years and included 11 747 females (55%). Among these studies, the median (range) follow-up duration was 12 (6-120) months. The pooled estimates of disability, pain, and physical function showed that patients with depression experienced a greater magnitude of improvement compared with patients without depression, but this difference was not significant (SMD, 0.04 [95% CI, -0.02 to 0.10]; I2 = 75%; P = .21). Nonetheless, patients with depression presented with worse preoperative disease severity in disability, pain, and physical function (SMD, -0.52 [95% CI, -0.62 to -0.41]; I2 = 89%; P < .001), which remained worse postoperatively (SMD, -0.52 [95% CI, -0.75 to -0.28]; I2 = 98%; P < .001). There was no significant correlation between depression severity and the primary outcome. A multivariable metaregression analysis suggested that age, sex (male to female ratio), percentage of comorbidities, and follow-up attrition were significant sources of variance. Conclusions and Relevance: Results of this systematic review and meta-analysis suggested that, although patients with depression had worse disease severity both before and after surgery compared with patients without depression, they had significant potential for recovery in disability, pain, and physical function. Further investigations are needed to examine the association between spine-related disability and depression as well as the role of perioperative mental health treatments.

Impact of Upper Limb Motor Recovery on Functional Independence After Traumatic Low Cervical Spinal Cord Injury.

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.

Feasibility of postoperative diffusion-weighted imaging to assess representations of spinal cord microstructure in cervical spondylotic myelopathy.

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.

Predictors of Postoperative Segmental and Overall Lumbar Lordosis in Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Consecutive Case Series.

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 (ß = -.45° P = .001, ß = 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.

Mechanomyography as a Surgical Adjunct for Treatment of Chronic Entrapment Neuropathy: A Case Series.

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.

Association of upper-limb neurological recovery with functional outcomes in high cervical spinal cord injury.

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.

Geographic Distribution in Training and Practice of Academic Neurological and Orthopedic Spine Surgeons in the United States.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: This study aimed to stratify the geographic distribution of academic spine surgeons in the United States, analyzing how this distribution highlights differences in academic, demographic, professional metrics, and gaps in access to spine care. METHODS: Spine surgeons were identified using American Association of Neurological Surgeons and American Academy of Orthopedic Surgeons databases, categorizing into geographic regions of training and practice. Departmental websites, National Institutes of Health (NIH) RePort Expenditures and Results, Google Patent, and NIH icite databases were queried for demographic and professional metrics. RESULTS: Academic spine surgeons (347 neurological; 314 orthopedic) are predominantly male (95%) and few have patents (23%) or NIH funding (4%). Regionally, the Northeast has the highest proportion per capita (3.28 surgeons per million), but California is the state with the highest proportion (13%). The Northeast has the greatest regional retention post-residency at 74%, followed by the Midwest (59%). The West and South are more associated with additional degrees. Neurosurgery-trained surgeons hold more additional degrees (17%) than orthopedic surgeons (8%), whereas more orthopedic surgeons hold leadership positions (34%) than neurosurgeons (20%). CONCLUSIONS: Academic spine surgeons are found at the highest proportion in the Northeast and California; the Northeast has the greatest regional retention. Spine neurosurgeons have more additional degrees, whereas spine orthopedic surgeons have more leadership positions. These results are relevant to training programs looking to correct geographic disparities, surgeons in search of training programs, or students in pursuit of spine surgery.

Establishing the Reliability, Validity, and Prognostic Utility of the Momentary Pain Catastrophizing Scale for Use in Ecological Momentary Assessment Research.

Despite the marked increase in ecological momentary assessment research, few reliable and valid measures of momentary experiences have been established. The goal of this preregistered study was to establish the reliability, validity, and prognostic utility of the momentary Pain Catastrophizing Scale (mPCS), a 3-item measure developed to assess situational pain catastrophizing. Participants in 2 studies of postsurgical pain outcomes completed the mPCS 3 to 5 times per day prior to surgery (N = 494, T = 20,271 total assessments). The mPCS showed good psychometric properties, including multilevel reliability and factor invariance across time. Participant-level average mPCS was strongly positively correlated with dispositional pain catastrophizing as assessed by the Pain Catastrophizing Scale (r = .55 and .69 in study 1 and study 2, respectively). To establish prognostic utility, we then examined whether the mPCS improved prediction of postsurgical pain outcomes above and beyond one-time assessment of dispositional pain catastrophizing. Indeed, greater variability in momentary pain catastrophizing prior to surgery was uniquely associated with increased pain immediately after surgery (b = .58, P = .005), after controlling for preoperative pain levels and dispositional pain catastrophizing. Greater average mPCS score prior to surgery was also uniquely associated with lesser day-to-day improvement in postsurgical pain (b = .01, P = .003), whereas dispositional pain catastrophizing was not (b = -.007, P = .099). These results show that the mPCS is a reliable and valid tool for ecological momentary assessment research and highlight its potential utility over and above retrospective measures of pain catastrophizing. PERSPECTIVE: This article presents the psychometric properties and prognostic utility of a new measure to assess momentary pain catastrophizing. This brief, 3-item measure will allow researchers and clinicians to assess fluctuations in pain catastrophizing during individuals' daily lives, as well as dynamic relationships between catastrophizing, pain, and related factors.

Diffusion Basis Spectrum Imaging Identifies Clinically Relevant Disease Phenotypes of Cervical Spondylotic Myelopathy.

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.

Current and future applications of mobile health technology for evaluating spine surgery patients: a review.

Mobile health (mHealth) technology has assumed a pervasive role in healthcare and society. By capturing real-time features related to spine health, mHealth assessments have the potential to transform multiple aspects of spine care. Yet mHealth applications may not be familiar to many spine surgeons and other spine clinicians. Consequently, the objective of this narrative review is to provide an overview of the technology, analytical considerations, and applications of mHealth tools for evaluating spine surgery patients. Reflecting their near-ubiquitous role in society, smartphones are the most commonly available form of mHealth technology and can provide measures related to activity, sleep, and even social interaction. By comparison, wearable devices can provide more detailed mobility and physiological measures, although capabilities vary substantially by device. To date, mHealth evaluations in spine surgery patients have focused on the use of activity measures, particularly step counts, in an attempt to objectively quantify spine health. However, the correlation between step counts and patient-reported disease severity is inconsistent, and further work is needed to define the mobility metrics most relevant to spine surgery patients. mHealth assessments may also support a variety of other applications that have been studied less frequently, including those that prevent postoperative complications, predict surgical outcomes, and serve as motivational aids to patients. These areas represent key opportunities for future investigations. To maximize the potential of mHealth evaluations, several barriers must be overcome, including technical challenges, privacy and regulatory concerns, and questions related to reimbursement. Despite those obstacles, mHealth technology has the potential to transform many aspects of spine surgery research and practice, and its applications will only continue to grow in the years ahead.

Electroactive Spinal Instrumentation for Targeted Osteogenesis and Spine Fusion: A Computational Study.

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.

Feasibility and Acceptability of a Preoperative Multimodal Mobile Health Assessment in Spine Surgery Candidates.

BACKGROUND: Rapid growth in smartphone use has expanded opportunities to use mobile health (mHealth) technology to collect real-time patient-reported and objective biometric data. These data may have important implication for personalized treatments of degenerative spine disease. However, no large-scale study has examined the feasibility and acceptability of these methods in spine surgery patients. OBJECTIVE: To evaluate the feasibility and acceptability of a multimodal preoperative mHealth assessment in patients with degenerative spine disease. METHODS: Adults undergoing elective spine surgery were provided with Fitbit trackers and sent preoperative ecological momentary assessments (EMAs) assessing pain, disability, mood, and catastrophizing 5 times daily for 3 weeks. Objective adherence rates and a subjective acceptability survey were used to evaluate feasibility of these methods. RESULTS: The 77 included participants completed an average of 82 EMAs each, with an average completion rate of 86%. Younger age and chronic pulmonary disease were significantly associated with lower EMA adherence. Seventy-two (93%) participants completed Fitbit monitoring and wore the Fitbits for an average of 247 hours each. On average, participants wore the Fitbits for at least 12 hours per day for 15 days. Only worse mood scores were independently associated with lower Fitbit adherence. Most participants endorsed positive experiences with the study protocol, including 91% who said they would be willing to complete EMAs to improve their preoperative surgical guidance. CONCLUSION: Spine fusion candidates successfully completed a preoperative multimodal mHealth assessment with high acceptability. The intensive longitudinal data collected may provide new insights that improve patient selection and treatment guidance.

Incorporating Intraoperative Mechanomyography to Peripheral Nerve Decompression Surgery.

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.