A clinical model to predict postoperative improvement in sub-domains of the modified Japanese Orthopedic Association score for degenerative cervical myelopathy.

PURPOSE: The modified Japanese Orthopedic Association (mJOA) score consists of six sub-domains and is used to quantify the severity of cervical myelopathy. The current study aimed to assess for predictors of postoperative mJOA sub-domains scores following elective surgical management for patients with cervical myelopathy and develop the first clinical prediction model for 12-month mJOA sub-domain scores.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [Byron F.] Last name [Stephens], Author 2 Given name: [Lydia J.] Last name [McKeithan], Author 3 Given name: [W. Hunter] Last name [Waddell], Author 4 Given name: [Anthony M.] Last name [Steinle], Author 5 Given name: [Wilson E.] Last name [Vaughan], Author 6 Given name: [Jacquelyn S.] Last name [Pennings], Author 7 Given name: [Jacquelyn S.] Last name [Pennings], Author 8 Given name: [Scott L.] Last name [Zuckerman], Author 9 Given name: [Kristin R.] Last name [Archer], Author 10 Given name: [Amir M.] Last name [Abtahi] Also, kindly confirm the details in the metadata are correct.Last Author listed should be Kristin R. Archer METHODS: A multivariable proportional odds ordinal regression model was developed for patients with cervical myelopathy. The model included patient demographic, clinical, and surgery covariates along with baseline sub-domain scores. The model was internally validated using bootstrap resampling to estimate the likely performance on a new sample of patients. RESULTS: The model identified mJOA baseline sub-domains to be the strongest predictors of 12-month scores, with numbness in legs and ability to walk predicting five of the six mJOA items. Additional covariates predicting three or more items included age, preoperative anxiety/depression, gender, race, employment status, duration of symptoms, smoking status, and radiographic presence of listhesis. Surgical approach, presence of motor deficits, number of surgical levels involved, history of diabetes mellitus, workers' compensation claim, and patient insurance had no impact on 12-month mJOA scores. CONCLUSION: Our study developed and validated a clinical prediction model for improvement in mJOA scores at 12 months following surgery. The results highlight the importance of assessing preoperative numbness, walking ability, modifiable variables of anxiety/depression, and smoking status. This model has the potential to assist surgeons, patients, and families when considering surgery for cervical myelopathy. LEVEL OF EVIDENCE: Level III.

Comparing Calcaneus Fracture Radiographic Outcomes and Complications after Percutaneous Pin versus Screw Fixation.

Calcaneus fracture fixation is associated with high rates of morbidity and disability from wound complications, infection, subtalar arthritis, and malunion. Percutaneous fixation with Kirshner wires (K-wires) or screws may be implemented when soft tissue injury precludes an open approach. Although screws are thought to provide greater stability, limited data exists directly comparing fixation success of these implants. Medical record data from 53 patients (62 total fractures) surgically treated with percutaneous screws (28 fractures) or K-wires (34 fractures) for joint-depression calcaneus fractures at a large tertiary hospital were retrospectively reviewed. Bohler's angle and calcaneal varus were assessed from available radiographs at time of injury, postoperatively, and at final follow-up, and joint congruity was assessed postoperatively and at final follow-up. Complications were also extracted. There were no statistical differences in patient characteristics between surgical groups although a higher proportion of patients treated with K-wires compared to screws had other associated injuries (79% vs 42%, p = .01). A higher proportion of fractures treated with screws compared to K-wires maintained joint congruity at the final follow-up (69% vs 32%, p = .005). However, there were no statistically detectable differences in other postoperative radiographic metrics (p > .05). In conclusion, joint congruity was more often maintained with screw fixation although there was no statistical difference in restoration and maintenance of Bohler's angle or varus alignment. The difference in radiographic metrics was not correlated with secondary procedures, namely subtalar arthrodesis, and may not be clinically significant. Neither group was completely effective in attaining and maintaining reduction, and additional fixation strategies should be considered if feasible based on patient, injury, and soft tissue characteristics.

Outcomes Following Direct Versus Indirect Decompression Techniques for Lumbar Spondylolisthesis: A Propensity-Matched Analysis.

STUDY DESIGN: Retrospective review. OBJECTIVE: The aim was to compare outcomes at 3 and 12 months for patients with lumbar spondylolisthesis treated with direct decompression (DD) versus indirect decompression (ID) techniques. SUMMARY OF BACKGROUND DATA: Debate persists regarding the optimal surgical strategy to treat lumbar spondylolisthesis. Novel techniques relying on ID have shown superior radiographic outcomes compared to DD, however, doubt remains regarding their effectiveness in achieving adequate decompression. Currently, there is a paucity of data comparing the clinical efficacy of DD to ID. METHODS: The Quality Outcomes Database (QOD), a national, multicenter prospective spine registry, was queried for patients who underwent DD and ID between April 2013 and January 2019. Propensity scores for each treatment were estimated using logistic regression dependent on baseline covariates potentially associated with outcomes. The propensity scores were used to exclude nonsimilar patients. Multivariable regression analysis was performed with the treatment and covariate as independent variables and outcomes as dependent variables. RESULTS: A total of 4163 patients were included in the DD group and 86 in the ID group. The ID group had significantly lower odds of having a longer hospital stay and for achieving 30% improvement in back and leg pain at 3 months. These trends were not statistically significant at 12 months. There were no differences in ED5D scores or Oswestry disability index 30% improvement scores at 3 or 12 months. ID patient had a significantly higher rate of undergoing a repeat operation at 3 months (4.9% vs. 1.5%, P =0.015). CONCLUSION: Our study suggests that both DD and ID for the treatment of lumbar spondylolisthesis result in similar clinical outcomes, with the exception that those treated with ID experienced a lower reduction in back and leg pain at 3 months and a higher 3-month reoperation rate. This data can provide surgeons with additional information when counseling patients on the pros and cons of ID versus DD surgery.

Foot Drop, Hindfoot Varus, and Tibialis Posterior Tendon Transfer in Cerebral Palsy.

The transfer of the tibialis posterior tendon has been used to correct hindfoot varus and dorsiflexion weakness in cerebral palsy. It is expendable, has a favorable direction for dorsiflexion and eversion posterior to the tibia, and is the source of hindfoot varus in most cases. However, the foot and ankle must be flexible without skeletal deformity. The electromyography of the tibialis posterior should be present in the swing phase for the tendon transfer to function correctly. Techniques and pitfalls are described to plan and execute a successful tibialis posterior tendon transfer.

Variable Response to Antifibrinolytics Correlates with Blood-loss and Transfusion in Posterior Spinal Fusion.

PURPOSE: Posterior spinal fusion (PSF) activates the fibrinolytic protease plasmin, which is implicated in blood loss and transfusion. While antifibrinolytic drugs have improved blood loss and reduced transfusion, variable blood loss has been observed in similar PSF procedures treated with the same dose of antifibrinolytics. However, both the cause of this and the appropriate measures to determine antifibrinolytic efficacy during high-blood-loss spine surgery are unknown, making clinical trials to optimize antifibrinolytic dosing in PSF difficult. We hypothesized that patients undergoing PSF respond differently to antifibrinolytic dosing, resulting in variable blood loss, and that specific diagnostic markers of plasmin activity will accurately measure the efficacy of antifibrinolytics in PSF. METHODS: A prospective study of 17 patients undergoing elective PSF with the same dosing regimen of TXA was conducted. Surgery-induced plasmin activity was exhaustively analyzed in perioperative blood samples and correlated to measures of inflammation, bleeding, and transfusion. RESULTS: While markers of in vivo plasmin activation (PAP and D-dimer) suggested significant breakthrough plasmin activation and fibrinolysis (P < 0.01), in vitro plasmin assays, including TEG, did not detect plasmin activation. In vivo measures of breakthrough plasmin activation correlated with blood loss (R2 = 0.400, 0.264; P < 0.01), transfusions (R2 = 0.388; P < 0.01), and complement activation (R2 = 0.346, P < 0.05). CONCLUSIONS: Despite all patients receiving a high dose of TXA, its efficacy among patients was variable, indicated by notable intra-operative plasmin activity. Markers of in vivo plasmin activation best correlated with clinical outcomes. These findings suggest that the efficacy of antifibrinolytic therapy to inhibit plasmin in PSF surgery should be determined by markers of in vivo plasmin activation in future studies. LEVEL OF EVIDENCE: Level II-diagnostic.

Factors That Drive Annual Variation in Pediatric Elbow Fracture Occurrence, Severity, and Resource Utilization.

BACKGROUND: Elbow fractures are the most common pediatric fractures requiring operative treatment. To date, few studies have examined what annual factors drive pediatric elbow fracture incidence and no studies have examined which annual factors drive elbow fracture severity or resource utilization. The goal of this study was to not only document the annual patterns of pediatric elbow fracture incidence and severity but also the impact of these patterns on resource utilization in the emergency department, emergency medical service transportation, and the operating room (OR). METHODS: Retrospective cohort study of 4414 pediatric elbow fractures from a single tertiary hospital (2007 to 2017). Exclusion criteria included outside treatment or lack of diagnosis by an orthopaedist. Presentation information, injury patterns, transport, and treatment requirements were collected. Pearson correlations were used to analyze factors influencing fracture incidence, severity, and resource utilization. RESULTS: Pediatric elbow fracture incidence positively correlated with monthly daylight hours, but significantly fewer elbow fractures occurred during summer vacation from school compared with surrounding in school months. While fewer overall fractures occurred during summer break, the fractures sustained were greater in severity, conferring higher rates of displacement, higher risk of neurovascular injury, and greater needs for emergency transportation and operative treatment. Yearly, elbow fractures required 320.6 OR hours (7.7% of all pediatric orthopaedic OR time and 12.3% of all pediatric orthopaedic operative procedures), 203.4 hospital admissions, and a total of 4753.7 miles traveled by emergency medical service transportation to manage. All-cause emergency department visits were negatively correlated with daylight hours, inversing the pattern seen in elbow fractures. CONCLUSION: Increased daylight, while school was in session, was a major driver of the incidence of pediatric elbow fractures. While summer vacation conferred fewer fractures, these were of higher severity. As such, increased daylight correlated strongly with monthly resource utilization, including the need for emergency transportation and operative treatment. This study provides objective data by which providers and administrators can more accurately allocate resources. LEVEL OF EVIDENCE: Level III-Retrospective comparative study.

Multi-shot acquisitions for stimulus-evoked spinal cord BOLD fMRI.

PURPOSE: To demonstrate the feasibility of 3D multi-shot magnetic resonance imaging acquisitions for stimulus-evoked blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) in the human spinal cord in vivo. METHODS: Two fMRI studies were performed at 3T. The first study was a hypercapnic gas challenge where data were acquired from healthy volunteers using a multi-shot 3D fast field echo (FFE) sequence as well as single-shot multi-slice echo-planar imaging (EPI). In the second study, another cohort of healthy volunteers performed an upper extremity motor task while fMRI data were acquired using a 3D multi-shot acquisition. RESULTS: Both 2D-EPI and 3D-FFE were shown to be sensitive to BOLD signal changes in the cervical spinal cord, and had comparable contrast-to-noise ratios in gray matter. FFE exhibited much less signal drop-out and weaker geometric distortions compared to EPI. In the motor paradigm study, the mean number of active voxels was highest in the ventral gray matter horns ipsilateral to the side of the task and at the spinal level associated with innervation of finger extensors. CONCLUSIONS: Highly multi-shot acquisition sequences such as 3D-FFE are well suited for stimulus-evoked spinal cord BOLD fMRI.

The cost of a single concussion in American high school football: a retrospective cohort study.

AIM: The potential financial burden of American football-related concussions (FRC) is unknown. Our objective was to describe the healthcare costs associated with an FRC and determine factors associated with increased costs. METHODOLOGY/RESULTS: A retrospective cohort study of concussed high school football players presenting between November 2017 and March 2020 was undertaken; 144 male high school football players were included. Total costs were about $115,000, for an average direct healthcare cost of $800.10/concussion. Visiting the emergency department (ß = 502.29, 95% CI: 105.79-898.61; p = 0.01), the initial post-concussion symptom scale score (ß = 0.39, 95% CI: 0.11-0.66; p = 0.01) and a post-concussion syndrome diagnosis (ß = 670.37, 95% CI: 98.96-1241.79; p = 0.02) were each independently associated with total costs. CONCLUSION: A granular understanding of cost-driving factors associated with FRC is the first step in understanding the cost-effectiveness of prevention and treatment methods.

7T quantitative magnetization transfer (qMT) of cortical gray matter in multiple sclerosis correlates with cognitive impairment.

Cognitive impairment (CI) is a major manifestation of multiple sclerosis (MS) and is responsible for extensively hindering patient quality of life. Cortical gray matter (cGM) damage is a significant contributor to CI, but is poorly characterized by conventional MRI let alone with quantitative MRI, such as quantitative magnetization transfer (qMT). Here we employed high-resolution qMT at 7T via the selective inversion recovery (SIR) method, which provides tissue-specific indices of tissue macromolecular content, such as the pool size ratio (PSR) and the rate of MT exchange (kmf). These indices could represent expected demyelination that occurs in the presence of gray matter damage. We utilized selective inversion recovery (SIR) qMT which provides a low SAR estimate of macromolecular-bulk water interactions using a tailored, B1 and B0 robust inversion recovery (IR) sequence acquired at multiple inversion times (TI) at 7T and fit to a two-pool model of magnetization exchange. Using this sequence, we evaluated qMT indices across relapsing-remitting multiple sclerosis patients (N = 19) and healthy volunteers (N = 37) and derived related associations with neuropsychological measures of cognitive impairment. We found a significant reduction in kmf in cGM of MS patients (15.5%, p = 0.002), unique association with EDSS (ρ = -0.922, p = 0.0001), and strong correlation with cognitive performance (ρ = -0.602, p = 0.0082). Together these findings indicate that the rate of MT exchange (kmf) may be a significant biomarker of cGM damage relating to CI in MS.

Glutamate-sensitive imaging and evaluation of cognitive impairment in multiple sclerosis.

BACKGROUND: Cognitive impairment (CI) profoundly impacts quality of life for patients with multiple sclerosis (MS). Dysfunctional regulation of glutamate in gray matter (GM) has been implicated in the pathogenesis of MS by post-mortem pathological studies and in CI by in vivo magnetic resonance spectroscopy, yet GM pathology is subtle and difficult to detect using conventional T1- and T2-weighted magnetic resonance imaging (MRI). There is a need for high-resolution, clinically accessible imaging techniques that probe molecular changes in GM. OBJECTIVE: To study cortical GM pathology related to CI in MS using glutamate-sensitive chemical exchange saturation transfer (GluCEST) MRI at 7.0 Tesla (7T). METHODS: A total of 20 patients with relapsing-remitting MS and 20 healthy controls underwent cognitive testing, anatomical imaging, and GluCEST imaging. Glutamate-sensitive image contrast was quantified for cortical GM, compared between cohorts, and correlated with clinical measures of CI. RESULTS AND CONCLUSION: Glutamate-sensitive contrast was significantly increased in the prefrontal cortex of MS patients with accumulated disability (p < 0.05). In addition, glutamate-sensitive contrast in the prefrontal cortex was significantly correlated with symbol digit modality test (rS = -0.814) and choice reaction time (rS = 0.772) scores in patients (p < 0.05), suggesting that GluCEST MRI may have utility as a marker for GM pathology and CI.

A football helmet prototype that reduces linear and rotational acceleration with the addition of an outer shell.

OBJECTIVEAmid the public health controversy surrounding American football, a helmet that can reduce linear and rotational acceleration has the potential to decrease forces transmitted to the brain. The authors hypothesized that a football helmet with an outer shell would reduce both linear and rotational acceleration. The authors' objectives were to 1) determine an optimal material for a shock-absorbing outer shell and 2) examine the ability of an outer shell to reduce linear and/or rotational acceleration.METHODSA laboratory-based investigation was undertaken using an extra-large Riddell Revolution football helmet. Two materials (Dow Corning Dilatant Compound and Sorbothane) were selected for their non-Newtonian properties (changes in viscosity with shear stress) to develop an outer shell. External pads were attached securely to the helmet at 3 locations: the front boss, the side, and the back. The helmet was impacted 5 times per location at 6 m/sec with pneumatic ram testing. Two-sample t-tests were used to evaluate linear/rotational acceleration differences between a helmet with and a helmet without the outer shell.RESULTSSorbothane was superior to the Dow Corning compound in force reduction and recovered from impact without permanent deformation. Of 5 different grades, 70-duro (a unit of hardness measured with a durometer) Sorbothane was found to have the greatest energy dissipation and stiffness, and it was chosen as the optimal outer-shell material. The helmet prototype with the outer shell reduced linear acceleration by 5.8% (from 75.4g to 71.1g; p < 0.001) and 10.8% (from 89.5g to 79.8g; p = 0.033) at the side and front boss locations, respectively, and reduced rotational acceleration by 49.8% (from 9312.8 rad/sec2 to 4671.7 rad/sed2; p < 0.001) at the front boss location.CONCLUSIONSSorbothane (70 duro) was chosen as the optimal outer-shell material. In the outer-shell prototype helmet, the results demonstrated a 5%-10% reduction in linear acceleration at the side and front boss locations, and a 50% reduction in rotational acceleration at the front boss location. Given the paucity of publicly reported helmet-design literature and the importance of rotational acceleration in head injuries, the substantial reduction seen in rotational acceleration with this outer-shell prototype holds the potential for future helmet-design improvements.

Evaluating single-point quantitative magnetization transfer in the cervical spinal cord: Application to multiple sclerosis.

Spinal cord (SC) damage is linked to clinical deficits in patients with multiple sclerosis (MS), however, conventional MRI methods are not specific to the underlying macromolecular tissue changes that may precede overt lesion detection. Single-point quantitative magnetization transfer (qMT) is a method that can provide high-resolution indices sensitive to underlying macromolecular composition in a clinically feasible scan time by reducing the number of MT-weighted acquisitions and utilizing a two-pool model constrained by empirically determined constants. As the single-point qMT method relies on a priori constraints, it has not been employed extensively in patients, where these constraints may vary, and thus, the biases inherent in this model have not been evaluated in a patient cohort. We, therefore, addressed the potential biases in the single point qMT model by acquiring qMT measurements in the cervical SC in patient and control cohorts and evaluated the differences between the control and patient-derived qMT constraints (kmf, T2fR1f, and T2m) for the single point model. We determined that the macromolecular to free pool size ratio (PSR) differences between the control and patient-derived constraints are not significant (p > 0.149 in all cases). Additionally, the derived PSR for each cohort was compared, and we reported that the white matter PSR in healthy volunteers is significantly different from lesions (p < 0.005) and normal appearing white matter (p < 0.02) in all cases. The single point qMT method is thus a valuable method to quantitatively estimate white matter pathology in MS in a clinically feasible scan time.