Effect of Ventral vs Dorsal Spinal Surgery on Patient-Reported Physical Functioning in Patients With Cervical Spondylotic Myelopathy: A Randomized Clinical Trial.

Importance: Cervical spondylotic myelopathy is the most common cause of spinal cord dysfunction worldwide. It remains unknown whether a ventral or dorsal surgical approach provides the best results. Objective: To determine whether a ventral surgical approach compared with a dorsal surgical approach for treatment of cervical spondylotic myelopathy improves patient-reported physical functioning at 1 year. Design, Setting, and Participants: Randomized clinical trial of patients aged 45 to 80 years with multilevel cervical spondylotic myelopathy enrolled at 15 large North American hospitals from April 1, 2014, to March 30, 2018; final follow-up was April 15, 2020. Interventions: Patients were randomized to undergo ventral surgery (n = 63) or dorsal surgery (n = 100). Ventral surgery involved anterior cervical disk removal and instrumented fusion. Dorsal surgery involved laminectomy with instrumented fusion or open-door laminoplasty. Type of dorsal surgery (fusion or laminoplasty) was at surgeon's discretion. Main Outcomes and Measures: The primary outcome was 1-year change in the Short Form 36 physical component summary (SF-36 PCS) score (range, 0 [worst] to 100 [best]; minimum clinically important difference = 5). Secondary outcomes included 1-year change in modified Japanese Orthopaedic Association scale score, complications, work status, sagittal vertical axis, health resource utilization, and 1- and 2-year changes in the Neck Disability Index and the EuroQol 5 Dimensions score. Results: Among 163 patients who were randomized (mean age, 62 years; 80 [49%] women), 155 (95%) completed the trial at 1 year (80% at 2 years). All patients had surgery, but 5 patients did not receive their allocated surgery (ventral: n = 1; dorsal: n = 4). One-year SF-36 PCS mean improvement was not significantly different between ventral surgery (5.9 points) and dorsal surgery (6.2 points) (estimated mean difference, 0.3; 95% CI, -2.6 to 3.1; P = .86). Of 7 prespecified secondary outcomes, 6 showed no significant difference. Rates of complications in the ventral and dorsal surgery groups, respectively, were 48% vs 24% (difference, 24%; 95% CI, 8.7%-38.5%; P = .002) and included dysphagia (41% vs 0%), new neurological deficit (2% vs 9%), reoperations (6% vs 4%), and readmissions within 30 days (0% vs 7%). Conclusions and Relevance: Among patients with cervical spondylotic myelopathy undergoing cervical spinal surgery, a ventral surgical approach did not significantly improve patient-reported physical functioning at 1 year compared with outcomes after a dorsal surgical approach. Trial Registration: ClinicalTrials.gov Identifier: NCT02076113.

A guide to finite element analysis models of the spine for clinicians.

Finite element analysis (FEA) is a computer-based mathematical method commonly used in spine and orthopedic biomechanical research. Advances in computational power and engineering modeling and analysis software have enabled many recent technical applications of FEA. Through the use of FEA, a wide range of scenarios can be simulated, such as physiological processes, mechanisms of disease and injury, and the efficacy of surgical procedures. Such models have the potential to enhance clinical studies by allowing comparisons of surgical treatments that would be impractical to perform in human or animal studies, and by linking model results to treatment outcomes. While traditional ex vivo experiments are limited by variabilities in tissue, the complexity of test setup, cost, measurable biomechanical parameters, and the repeatability of experiments, FEA models can be used to measure a wide range of clinically relevant biomechanical parameters. Generic or patient-specific anatomical models can be modified to simulate different clinical and surgical conditions under simulated physiological conditions. Despite these capabilities, there is limited understanding of the clinical applicability and translational potential of FEA models. For spine surgeons, a comprehensive understanding of the key features, strengths, and limitations of FEA models of the spine and their ability to personalize treatment options and assist in clinical decision-making would significantly enhance the impact of FEA research. Furthermore, fostering collaborations between surgeons and engineers could augment the clinical use of these models. The purpose of this review was to highlight key features of FEA model building for clinicians. To illustrate these features, the authors present an example of the use of FEA models in comparing FDA-approved disc arthroplasty implants.

People with degenerative cervical myelopathy have impaired reactive balance during walking.

BACKGROUND: People with degenerative cervical myelopathy are known to have impaired standing balance and walking abilities, but less is known about balance responses during walking. RESEARCH QUESTION: The aim of this project was to assess reactive balance impairments during walking in people with degenerative cervical myelopathy (PwDCM). We hypothesized that center of mass motion following perturbations would be larger in PwDCM and gluteus medius electromyographic amplitude responses would be decreased in PwDCM. METHODS: Reactive balance responses were quantified during unanticipated lateral pulls to the waist while treadmill walking. Walking biomechanics data were collected from 10 PwDCM (F=6) and 10 non-myelopathic controls (F=7) using an 8 camera Vicon System (Vicon MX T-Series). Electromyography was collected from lower limb muscles. Participants walked on an instrumented treadmill and received lateral pulls at random intervals and in randomized direction at 5% and 2.5% body mass. Participants walked at 3 prescribed foot placements to control for effects of the size of base of support. RESULTS: As compared with controls, the perturbation-related positional change of the center of mass motion (ΔCOM) was increased in PwDCM (p=0.001) with similar changes in foot placement (p>0.05). Change in gluteus medius electromyography, however, was less in PwDCM than in controls (p<0.001). SIGNIFICANCE: After experimentally controlling step width, people with mild-to-moderate degenerative cervical myelopathy at least 3 months following cervical spine surgery have impaired reactive balance during walking likely coupled with reduced gluteus medius electromyographic responses. Rehabilitation programs focusing on reactive balance and power are likely necessary for this population.

Impact of postsurgical rehabilitation on outcomes for degenerative cervical myelopathy.

OBJECTIVE: Despite widespread use, there is limited evidence to support postsurgical rehabilitation to enhance neurological recovery after surgery for degenerative cervical myelopathy (DCM). Outcomes research for DCM seldom accounts for the effect of postsurgical rehabilitation. The aim of this study was to quantify the impact of postsurgical rehabilitation on outcomes after surgery for DCM. METHODS: This was a retrospective analysis of prospectively collected data from a single center. The study enrolled 66 patients who underwent spinal surgery for DCM. In addition to patient demographic, imaging, and surgical data, chart review was performed to document the timing, type, duration, and outcomes of postsurgical rehabilitation therapy. Outcomes were collected prospectively, including the modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI) score, and SF-36 physical component summary (PCS) score. Linear regression models were created to determine the independent effects of type and timing of postsurgical occupational therapy (OT) and physical therapy (PT) on outcomes. RESULTS: A total of 66 patients were included in the analysis. Multivariate regression analysis showed that postsurgical OT was associated with significantly greater improvement in 12-month SF-36 PCS scores (p = 0.009) and mJOA scores (p = 0.019). In the subset of patients who received therapy, delayed therapy (> 42 days after surgery) compared to early therapy (< 42 days after surgery) was associated with less improvement in SF-36 PCS scores (p = 0.03). CONCLUSIONS: Postsurgical outpatient rehabilitation was independently associated with improved postsurgical outcomes within the 1st year after surgery for DCM, and early therapy (< 42 days) was associated with superior outcomes compared to delayed therapy. This is one of the first studies to use a prospective database to demonstrate an independent effect for postsurgical rehabilitation on outcomes after surgery for DCM.

Patients May Return to Work Sooner After Laminoplasty: Occupational Outcomes of the Cervical Spondylotic Myelopathy Surgical Trial.

BACKGROUND AND OBJECTIVES: Return-to-work (RTW) is an important outcome for employed patients considering surgery for cervical spondylotic myelopathy (CSM). We conducted a post hoc analysis of patients as-treated in the Cervical Spondylotic Myelopathy Surgical Trial, a prospective, randomized trial comparing surgical approaches for CSM to evaluate factors associated with RTW. METHODS: In the trial, patients were randomized (2:3) to either anterior surgery (anterior cervical decompression/fusion [ACDF]) or posterior surgery (laminoplasty [LP], or posterior cervical decompression/fusion [PCDF], at surgeon's discretion). Work status was recorded at 1, 3, 6, and 12 months postoperatively. For patients working full-time or part-time on enrollment, time to RTW was compared across as-treated surgical groups using discrete-time survival analysis. Multivariate logistic regression was used to assess predictors of RTW. Clinical outcomes were compared using a linear mixed-effects model. RESULTS: A total of 68 (42%) of 163 patients were working preoperatively and were analyzed. In total, 27 patients underwent ACDF, 29 underwent PCDF, and 12 underwent LP. 45 (66%) of 68 patients returned to work by 12 months. Median time to RTW differed by surgical approach (LP = 1 month, ACDF = 3 months, PCDF = 6 months; P = .02). Patients with longer length-of-stay were less likely to be working at 1 month (odds ratio 0.51; 95% CI, 0.29-0.91; P = .022) and 3 months (odds ratio 0.39; 95% CI, 0.16-0.96; P = .04). At 3 months, PCDF was associated with lower Short-Form 36 physical component summary scores than ACDF (estimated mean difference [EMD]: 6.42; 95% CI, 1.4-11.4; P = .007) and LP (EMD: 7.98; 95% CI, 2.7-13.3; P = .003), and higher Neck Disability Index scores than ACDF (EMD: 12.48; 95% CI, 2.3-22.7; P = .01) and LP (EMD: 15.22; 95% CI, 2.3-28.1; P = .014), indicating worse perceived physical functioning and greater disability, respectively. CONCLUSION: Most employed patients returned to work within 1 year. LP patients resumed employment earliest, while PCDF patients returned to work latest, with greater disability at follow-up, suggesting that choice of surgical intervention may influence occupational outcomes.

Characterization and limitations of diffusion tensor imaging metrics in the cervical spinal cord in neurologically intact subjects.

PURPOSE: To characterize diffusion tensor imaging (DTI) metrics across all levels of the cervical spinal cord (CSC) and to study the impact of age and signal quality on these metrics. MATERIALS AND METHODS: DTI metrics were calculated for gray matter (GM) and white matter (WM) funiculi throughout the CSC (C1-T1) in 25 healthy subjects (22-85 years old). Signal-to-noise ratios (SNRs) and mean DTI metrics were measured for the upper (C1-3), middle (C4-6) and lower (C7-T1) cervical segments. Age-related changes in DTI metrics were analyzed for the individual segment groups. RESULTS: Fractional anisotropy (FA), mean diffusivity (MD) and transverse apparent diffusion coefficient (tADC) showed significant differences between GM and WM funiculi. Significant age-related changes were observed in FA in upper and middle CSC segments but not in the lower CSC. The median SNR was significantly lower in the middle and lower segment groups as compared to the upper levels, contributing to poor spatial resolution in these regions. CONCLUSION: This study provides DTI data for GM and WM funiculi throughout the CSC. While DTI metrics may be used to define cord pathology, variations in metrics due to age and signal quality need to be accounted for before making definitive conclusions.

Diagnostic Imaging in Spinal Cord Injury.

In the evaluation of spinal trauma, diagnostic imaging is of paramount importance. Computed tomography (CT), flexion/extension radiographs, and MRI are complementary modalities. CT is typically obtained in the initial setting of spinal trauma and provides detailed information about osseous structures. MRI provides detailed information about structural injury to the spinal cord. Diffusion tensor imaging provides microstructural information about the integrity of the axons and myelin sheaths, but its clinical use is limited. Novel imaging techniques may be better suited for the acute clinical setting and are under development for potential future clinical use.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Perioperative Spine: Preoperative Pulmonary Evaluation and Optimization.

BACKGROUND: There are no current recommendations for preoperative pulmonary evaluation and management of patients undergoing elective spine surgery. OBJECTIVE: The aim of this guideline is to determine preoperative risk factors for perioperative and postoperative pulmonary adverse events and to determine the optimal preoperative evaluation and management of at-risk patients. METHODS: A systematic review of the literature was performed using the National Library of Medicine PubMed database and the Cochrane Library for studies relevant to postoperative pulmonary adverse events in patients undergoing spine surgery. Clinical studies evaluating preoperative patient risk factors and preoperative diagnostic and treatment interventions were selected for review. RESULTS: The literature search yielded 152 abstracts relevant to the PICO (patient/population, intervention, comparison, and outcomes) questions included in this chapter. The task force selected 65 articles for full-text review, and 24 were selected for inclusion in this systematic review. Twenty-three articles addressed preoperative patient risk factors. One article addressed preoperative diagnostic studies of pulmonary function. There were no studies meeting the inclusion criteria for preoperative pulmonary treatment. CONCLUSION: There is substantial evidence for multiple preoperative patient factors that predict an increased risk of a postoperative pulmonary adverse event. Individuals with these risk factors (functional dependence, advanced age [≥65 yr], chronic obstructive pulmonary disease, congestive heart failure, weight loss, and obstructive sleep apnea) who are undergoing spine surgery should be counseled regarding the potential increased risk of a perioperative and postoperative pulmonary adverse events. There is insufficient evidence to support any specific preoperative diagnostic test for predicting the risk of postoperative pulmonary adverse events or any treatment intervention that reduces risk. It is suggested, however, to consider appropriate preoperative pulmonary diagnostic testing and treatment to address active pulmonary symptoms of existing or suspected disease.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/5-preoperative-pulmonary-evaluation-optimization.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Perioperative Spine: Preoperative Opioid Evaluation.

BACKGROUND: Opioid use disorders in the United States have rapidly increased, yet little is known about the relationship between preoperative opioid duration and dose and patient outcomes after spine surgery. Likewise, the utility of preoperative opioid weaning is poorly understood. OBJECTIVE: The purpose of this evidence-based clinical practice guideline is to determine if duration and dose of preoperative opioids or preoperative opioid weaning is associated with patient-reported outcomes or adverse events after elective spine surgery for degenerative conditions. METHODS: A systematic review of the literature was performed using the National Library of Medicine/PubMed database and Embase for studies relevant to opioid use among adult patients undergoing spine surgery. Clinical studies evaluating preoperative duration, dose, and opioid weaning and outcomes were selected for review. RESULTS: A total of 41 of 845 studies met the inclusion criteria and none were Level I evidence. The use of any opioids before surgery was associated with longer postoperative opioid use, and longer duration of opioid use was associated with worse outcomes, such as higher complications, longer length of stay, higher costs, and increased utilization of resources. There is insufficient evidence to support the efficacy of opioid weaning on postoperative opioid use, improving outcome, or reducing adverse events after spine surgery. CONCLUSION: This evidence-based clinical guideline provides Grade B recommendations that preoperative opioid use and longer duration of preoperative opioid use are associated with chronic postoperative opioid use and worse outcome after spine surgery. Insufficient evidence supports the efficacy of an opioid wean before spine surgery (Grade I).The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/1-preoperative-opioid-evaluation.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Perioperative Spine: Preoperative Osteoporosis Assessment.

BACKGROUND: Osteoporosis is a metabolic bone disease that commonly affects the elderly. Degenerative spinal disease that may require surgical intervention is also prevalent in this susceptible population. If undiagnosed or untreated before spine surgery, osteoporosis may result in an increased risk of postoperative adverse events. Nontreatment of osteoporosis preoperatively may be related to a poor understanding of bone physiology, a lack of standardized treatment algorithms, limited cost-effective interventions, and reluctance by spine surgeons to be the primary provider of osteoporosis management. OBJECTIVE: The objective of this evidence-based review is to develop guidelines for the preoperative assessment and treatment of osteoporosis in patients undergoing spine surgery. METHODS: A systematic review of the literature was performed using the National Library of Medicine/PubMed database and Embase for studies relevant to preoperative diagnostic studies that predict increased risk of osteoporosis-related postoperative adverse events and whether the preoperative treatment of low bone mineral density (BMD) in patients with osteoporosis improves outcome. RESULTS: Out of 281 studies, 17 met the inclusion criteria and were included for systematic review. The task force affirmed a Grade B recommendation that preoperative osteoporosis testing with a dual-energy X-ray absorptiometry scan (T-score < -2.5), a computed tomography scan (Hounsfield units <97.9), and serum vitamin D3 level (<20 ng/mL) predict an increased risk of osteoporosis-related adverse events after spine surgery. The task force determined a Grade B recommendation that preoperative osteoporosis treatment with teriparatide increases BMD, induces earlier and more robust fusion, and may improve select patient outcomes. There is insufficient evidence regarding preoperative treatment with bisphosphonates alone and postoperative outcome. CONCLUSION: This evidence-based clinical guideline provides a recommendation that patients with suspected osteoporosis undergo preoperative assessment and be appropriately counseled about the risk of postoperative adverse events if osteoporosis is confirmed. In addition, preoperative optimization of BMD with select treatments improves certain patient outcomes.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/3-preoperative-osteoporosis-assessment.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Perioperative Spine: Preoperative Nutritional Assessment.

BACKGROUND: Preoperative malnutrition has been implicated in adverse events after elective surgery, potentially impacting patient outcomes. OBJECTIVE: As a potentially modifiable risk factor, we sought to determine which assessments of nutritional status were associated with specific adverse events after spine surgery. In addition, we explored if a preoperative nutritional improvement intervention may be beneficial in lowering the rates of these adverse events. METHODS: The literature search yielded 115 abstracts relevant to the PICO (patient/population, intervention, comparison, and outcomes) questions included in this chapter. The task force selected 105 articles for full text review, and 13 met criteria for inclusion in this systematic review. RESULTS: Malnutrition, assessed preoperatively by a serum albumin <3.5 g/dL or a serum prealbumin <20 mg/dL, is associated with a higher rate of surgical site infections (SSIs), other wound complications, nonunions, hospital readmissions, and other medical complications after spine surgery. A multimodal nutrition management protocol decreases albumin and electrolyte deficiencies in patients with normal preoperative nutritional status. It also improves overall complication rates but does not specifically impact SSIs. CONCLUSION: It is recommended to assess nutritional status using either serum albumin or prealbumin preoperatively in patients undergoing spine surgery.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/4-preoperative-nutritional-assessment.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Perioperative Spine: Preoperative Surgical Risk Assessment.

BACKGROUND: Patient factors (increased body mass index [BMI], smoking, and diabetes) may impact outcomes after spine surgery. There is a lack of consensus regarding which factors should be screened for and potentially modified preoperatively to optimize outcome. OBJECTIVE: The purpose of this evidence-based clinical practice guideline is to determine if preoperative patient factors of diabetes, smoking, and increased BMI impact surgical outcomes. METHODS: A systematic review of the literature for studies relevant to spine surgery was performed using the National Library of Medicine PubMed database and the Cochrane Library. Clinical studies evaluating the impact of diabetes or increased BMI with reoperation and/or surgical site infection (SSI) were selected for review. In addition, the impact of preoperative smoking on patients undergoing spinal fusion was reviewed. RESULTS: A total of 699 articles met inclusion criteria and 64 were included in the systematic review. In patients with diabetes, a preoperative hemoglobin A1c (HbA1c) >7.5 mg/dL is associated with an increased risk of reoperation or infection after spine surgery. The review noted conflicting studies regarding the relationship between increased BMI and SSI or reoperation. Preoperative smoking is associated with increased risk of reoperation (Grade B). There is insufficient evidence that cessation of smoking before spine surgery decreases the risk of reoperation. CONCLUSION: This evidence-based guideline provides a Grade B recommendation that diabetic individuals undergoing spine surgery should have a preoperative HbA1c test before surgery and should be counseled regarding the increased risk of reoperation or infection if the level is >7.5 mg/dL. There is conflicting evidence that BMI correlates with greater SSI rate or reoperation rate (Grade I). Smoking is associated with increased risk of reoperation (Grade B) in patients undergoing spinal fusion.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/2-preoperative-surgical-risk-assessement.

Diffusion tensor imaging in cervical spondylotic myelopathy: a review.

Degenerative spondylotic myelopathy is the most common cause of spinal dysfunction, as well as nontraumatic spastic paraparesis and quadriparesis. Although conventional MRI is the gold standard for radiographic evaluation of the spinal cord, it has limited application for determining prognosis and recovery. In the last decade, diffusion tensor imaging (DTI), which is based on the property of preferential diffusion of water molecules, has gained popularity in evaluating patients with cervical spondylotic myelopathy (CSM). The use of DTI allows for evaluation of microstructural changes in the spinal cord not otherwise detected on routine conventional MRI. In this review, the authors describe the application of DTI in CSM evaluation and its role as an imaging biomarker to predict disease severity and prognosis.

Continuous improvement in patient safety and quality in neurological surgery: the American Board of Neurological Surgery in the past, present, and future.

The American Board of Neurological Surgery (ABNS) was incorporated in 1940 in recognition of the need for detailed training in and special qualifications for the practice of neurological surgery and for self-regulation of quality and safety in the field. The ABNS believes it is the duty of neurosurgeons to place a patient's welfare and rights above all other considerations and to provide care with compassion, respect for human dignity, honesty, and integrity. At its inception, the ABNS was the 13th member board of the American Board of Medical Specialties (ABMS), which itself was founded in 1933. Today, the ABNS is one of the 24 member boards of the ABMS.To better serve public health and safety in a rapidly changing healthcare environment, the ABNS continues to evolve in order to elevate standards for the practice of neurological surgery. In connection with its activities, including initial certification, recognition of focused practice, and continuous certification, the ABNS actively seeks and incorporates input from the public and the physicians it serves. The ABNS board certification processes are designed to evaluate both real-life subspecialty neurosurgical practice and overall neurosurgical knowledge, since most neurosurgeons provide call coverage for hospitals and thus must be competent to care for the full spectrum of neurosurgery.The purpose of this report is to describe the history, current state, and anticipated future direction of ABNS certification in the US.

The continued burden of spine fractures after motor vehicle crashes.

OBJECT: Spine fractures are a significant cause of morbidity and mortality after motor vehicle crashes (MVCs). Public health interventions, such as the National Highway Traffic Safety Administration's Federal Motor Vehicle Safety Standards, have led to an increase in automobiles with air bags and the increased use of seat belts to lessen injuries sustained from MVCs. The purpose of this study was to evaluate secular trends in the occurrence of spine fractures associated with MVCs and evaluate the association between air bag and seat belt use with spine fractures. METHODS: Using the Crash Outcome Data Evaluation System, a database of the police reports of all MVCs in Wisconsin linked to hospital records, the authors studied the occurrence of spine fractures and seat belt and air bag use from 1994 to 2002. Demographic information and crash characteristics were obtained from the police reports. Injury characteristics were determined using International Classification of Disease, 9th Revision, Clinical Modification (ICD-9-CM) hospital discharge codes. RESULTS: From 1994 to 2002, there were 29,860 hospital admissions associated with automobile or truck crashes. There were 20,276 drivers or front-seat passengers 16 years of age and older who were not missing ICD-9-CM discharge codes, seat belt or air bag data, and who had not been ejected from the vehicle. Of these, 2530 (12.5%) sustained a spine fracture. The occurrence of spine fractures increased over the study period, and the use of a seat belt plus air bag, and of air bags alone also increased during this period. However, the occurrence of severe spine fractures (Abbreviated Injury Scale Score > or =3) did not significantly increase over the study period. The use of both seat belt and air bag was associated with decreased odds of a spine fracture. Use of an air bag alone was associated with increased odds of a severe thoracic, but not cervical spine fracture. CONCLUSIONS: Among drivers and front-seat passengers admitted to the hospital after MVCs, the occurrence of spine fractures increased from 1994 to 2002 despite concomitant increases in seat belt and air bag use. However, the occurrence of severe spine fractures did not increase over the study period. The use of both seat belt and air bag is protective against spine fractures. Although the overall increased occurrence of spine fractures may appear contrary to the increased use of seat belts and air bags in general, it is possible that improved imaging technology may be associated with an increase in the diagnosis of relatively minor fractures. However, given the significant protective effects of both seat belt and air bag use against spine fractures, resources should continue to be dedicated toward increasing their use to mitigate the effects of MVCs.

Great Hospitals in North America: The Medical College of Wisconsin Neurological Surgery.

The Medical College of Wisconsin Department of Neurosurgery delivers subspecialty adult and pediatric neurosurgical care that is patient-centered, evidence-informed, and value-based. Medical College of Wisconsin research advances the science of neurological disease with the goal of a positive translational effect on clinical care. The department supports an environment of education and scholarship for trainees, faculty, and staff alike. The journey to become a neurosurgical center of excellence was accomplished with the leadership and foresight of the men and women who turned their dreams into reality. The establishment and rise of the department as a national force for neurosurgery and spine is an elegant example of the combination of individual leadership and foresight with synergistic institutional support.

Comparison between quantitative measurements of diffusion tensor imaging and T2 signal intensity in a large series of cervical spondylotic myelopathy patients for assessment of disease severity and prognostication of recovery.

OBJECTIVE: Cervical spondylotic myelopathy (CSM) is a common cause of spinal cord dysfunction. Recently, it has been shown that diffusion tensor imaging (DTI) may be a better biomarker than T2-weighted signal intensity (T2SI) on MRI for CSM. However, there is very little literature on a comparison between the quantitative measurements of DTI and T2SI in the CSM patient population to determine disease severity and recovery. METHODS: A prospective analysis of 46 patients with both preoperative DTI and T2-weighted MRI was undertaken. Normalized T2SI (NT2SI), regardless of the presence or absence of T2SI at the level of maximum compression (LMC), was determined by calculating the T2SI at the LMC/T2SI at the level of the foramen magnum. Regression analysis was performed to determine the relationship of fractional anisotropy (FA), a quantitative measure derived from DTI, and NT2SI individually as well their combination with baseline preoperative modified Japanese Orthopaedic Association (mJOA) score and ∆mJOA score at the 3-, 6-, 12-, and 24-month follow-ups. Goodness-of-fit analysis was done using residual diagnostics. In addition, mixed-effects regression analysis was used to evaluate the impact of FA and NT2SI individually. A p value < 0.05 was selected to indicate statistical significance. RESULTS: Regression analysis showed a significant positive correlation between FA at the LMC and preoperative mJOA score (p = 0.041) but a significant negative correlation between FA at the LMC and the ΔmJOA score at the 12-month follow-up (p = 0.010). All other relationships between FA at the LMC and the baseline preoperative mJOA score or ∆mJOA score at the 3-, 6-, and 24-month follow-ups were not statistically significant. For NT2SI and the combination of FA and NT2SI, no significant relationships with preoperative mJOA score or ∆mJOA at 3, 6, and 24 months were seen on regression analysis. However, there was a significant correlation of combined FA and NT2SI with ∆mJOA score at the 12-month follow-up. Mixed-effects regression revealed that FA measured at the LMC was the only significant predictor of ΔmJOA score (p = 0.03), whereas NT2SI and time were not. Goodness-of-fit analysis did not show any evidence of lack of fit. CONCLUSIONS: In this large prospective study of CSM patients, FA at LMC appears to be a better biomarker for determining long-term outcomes following surgery in CSM patients than NT2SI or the combination values at LMC.

Factors associated with chronic opioid use after cervical spine surgery for degenerative conditions.

OBJECTIVE: Opioids are commonly prescribed after surgery for painful spinal conditions, yet little is known about postoperative opioid use. The relationship between chronic opioid use and patient-reported outcomes and satisfaction with surgery is also unclear. The purpose of this study was to evaluate factors associated with opioid use 1 year after elective cervical spine surgery for degenerative conditions causing radiculopathy and myelopathy. The authors hypothesized that patients with preoperative opioid use would be more likely to report postoperative opioid use at 1 year, and that postoperative opioid use would be associated with patient-reported outcomes and dissatisfaction with surgery. METHODS: The authors performed a retrospective study of a prospective cohort of adult patients who underwent elective cervical spine surgery for degenerative changes causing radiculopathy or myelopathy. Patients were prospectively and consecutively enrolled from a single academic center after the decision for surgery had been made. Postoperative in-hospital pain management was conducted using a standardized protocol. The primary outcome was any opioid use 1 year after surgery. Secondary outcomes were the Neck Disability Index (NDI); 36-Item Short-Form Health Survey (SF-36) physical function (PF), bodily pain (BP), and mental component summary (MCS) scores; the modified Japanese Orthopaedic Association (mJOA) score among myelopathy patients; and patient expectations surveys. Patients with and without preoperative opioid use were compared using the chi-square and Student t-tests, and multiple logistic regression was used to study the associations between patient and surgical characteristics and postoperative opioid use 1 year after surgery. RESULTS: Two hundred eleven patients were prospectively and consecutively enrolled, of whom 39 were lost to follow-up for the primary outcome; 43.6% reported preoperative opioid use. Preoperative NDI and SF-36 PF and BP scores were significantly worse in the preoperative opioid cohort. More than 94% of both cohorts rated expectations of pain relief as extremely or somewhat important. At 1 year after surgery, 50.7% of the preoperative-opioid-use cohort reported ongoing opioid use, and 17.5% of patients in the no-preoperative-opioid-use cohort reported ongoing opioid use. Despite this, both cohorts reported similar improvements in NDI as well as SF-36 PF, BP, and MCS scores. More than 70% of both cohorts also reported being extremely or somewhat satisfied with pain relief after surgery. Predictors of 1-year opioid use included preoperative opioid use, duration of symptoms for more than 9 months before surgery, tobacco use, and higher comorbidity index. CONCLUSIONS: One year after elective cervical spine surgery, patients with preoperative opioid use were significantly more likely to report ongoing opioid use. However, patients in both groups reported similar improvements in patient-reported outcomes and satisfaction with pain relief. Interventions targeted at decreasing opioid use may need to focus on patient factors such as preoperative opioid use or duration of symptoms before surgery.

Variations in 30-day readmissions and length of stay among spine surgeons: a national study of elective spine surgery among US Medicare beneficiaries.

OBJECTIVE Pay-for-performance programs are targeting hospital readmissions. These programs have an underlying assumption that readmissions are due to provider practice patterns that can be modified by a reduction in reimbursement. However, there are limited data to support the role of providers in influencing readmissions. To study this, the authors examined variations in readmission rates by spine surgeon within 30 days among Medicare beneficiaries undergoing elective lumbar spine surgery for degenerative conditions. METHODS The authors applied validated ICD-9-CM algorithms to 2003-2007 Medicare data to select beneficiaries undergoing elective inpatient lumbar spine surgery for degenerative conditions. Mixed models, adjusting for patient demographics, comorbidities, and surgery type, were used to estimate risk of 30-day readmission by the surgeon. Length of stay (LOS) was also studied using these same models. RESULTS A total of 39,884 beneficiaries were operated on by 3987 spine surgeons. The mean readmission rate was 7.2%. The mean LOS was 3.1 days. After adjusting for patient characteristics and surgery type, 1 surgeon had readmission rates significantly below the mean, and only 5 surgeons had readmission rates significantly above the mean. In contrast, for LOS, the patients of 288 surgeons (7.2%) had LOS significantly lower than the mean, and the patients of 397 surgeons (10.0%) had LOS significantly above the mean. These findings were robust to adjustments for surgeon characteristics and clustering by hospital. Similarly, hospital characteristics were not significantly associated with readmission rates, but LOS was associated with hospital for-profit status and size. CONCLUSIONS The authors found almost no variations in readmission rates by surgeon. These findings suggest that surgeon practice patterns do not affect the risk of readmission. Likewise, no significant variation in readmission rates by hospital characteristics were found. Strategies to reduce readmissions would be better targeted at factors other than providers.

Interobserver Reliability of Magnetic Resonance Imaging Predictors of Outcome in Cervical Spine Degenerative Conditions.

BACKGROUND: Although recent work has focused on characterizing quantitative magnetic resonance imaging (MRI) markers that may predict outcome among patients with cervical degenerative conditions, little is known about their reliability. Measurement and reporting of these markers is time-consuming and nonstandardized, preventing routine use in clinical care. METHODS: We retrospectively analyzed cervical MRI among subjects prospectively enrolled in a health outcomes study of elective surgery for degenerative cervical spine conditions. Two radiologists independently reviewed MRI for presence or absence and length of cord signal change, level of worst cord compression, axial anteroposterior (AP) and lateral spinal cord diameter, midsagittal AP diameter, and kyphosis. Interobserver reliability was compared using kappa and intraclass correlation coefficient (ICC). RESULTS: Inclusion criteria were met by 209 patients who had MRI available for review. Most patients were female (58%) and middle-aged (mean age 51 years), and 54% had a diagnosis of myelopathy. Reliability was fair for cord signal change on T1 (κ = 0.33) and good on T2 (κ = 0.74) images. Among patients with T2 change (n = 22), reliability for signal change length was good (ICC = 0.67). For level of worst compression, reliability was good (κ = 0.79). For AP cord diameter, reliability was very good (ICC = 0.82; T2/midsagittal) and good (ICC = 0.66; T2/axial). Reliability was moderate for lateral cord diameter (ICC = 0.55; T2/axial) and good for kyphosis (κ = 0.76). CONCLUSIONS: Good and very good reliability observed in measuring T2-weighted spinal cord signal change, level of worst compression, AP cord diameter, and kyphosis support use of these markers in standardized reporting, which could be incorporated into routine clinical use.