Analyzing Pelvic Asymmetry by Sex and Ancestry: Insights From an Osteological Collection.

INTRODUCTION: Pelvic asymmetry has been noted in pelvic imaging, and might influence the development of various spinal pathologies, most notably scoliosis. There is a limited understanding of the relationship between pelvic asymmetry and sex and ancestry, and limited use of 3D modeling. The purpose of this study was to identify pelvic asymmetry and morphology differences between sex and ancestry utilizing 3D modeling on young adults in an osteological collection. METHODS: Thirty-three osteological pelvic specimens aged 18-25 years (average age 21.4 ± 2.0 years) were scanned to create virtual 3D models for analysis. Pelvic asymmetry and morphology were measured and compared across sex (male and female) and ancestry (European American and African American). Multivariate regression analysis was performed to examine the relationship between the variables measured. RESULTS: Multivariate regression analysis demonstrated statistically significant relationships between innominate-pelvic ring ratio and both sex (p < 0.001) and ancestry (p= 0.003) with larger ratios in male and African American specimens respectively. There was also a statistically significant relationship of greater sacral 1 coronal tilt in European American specimens (p= 0.042). There were no statistically significant differences with sex or ancestry in terms of innominate or sacral asymmetry. CONCLUSION: Although there are differences in overall pelvic shape between sex and ancestry, there is no relationship between these two variables versus pelvic asymmetry in the axial or sagittal planes in young adult osteological specimens.

Protocol-driven early tracheal extubation in patients with flaccid neuromuscular scoliosis and pre-existing lung disease.

PURPOSE: To review the results of a postoperative respiratory pathway for patients with muscular dystrophy (MD) and spinal muscular atrophy (SMA) undergoing spinal surgery. METHODS: With IRB approval, a retrospective review was done on all patients with SMA and MD undergoing spinal surgery on a neuromuscular protocol. Baseline demographics, perioperative results, and long-term outcomes were collected. Per the protocol, patients remained intubated after surgery and were transported to the intensive care unit (ICU) for extubation. We present the results of protocol implementation and compare patients with MD to those with SMA. RESULTS: Twenty-four patients were treated using the protocol. Average age was 13.1 years. Severe restrictive lung disease was present in 75% of patients. Nocturnal BiPAP was required in 68% of patients. Average number of instrumented levels was 17. All patients were immediately extubated upon entering the ICU. There were three respiratory complications and only was patient was re-intubated. Average ICU stay was 1.8 days and average hospital length of stay was 6.7 days. No differences in postoperative inspiratory or expiratory positive airway pressures were observed between the MD and SMA groups. CONCLUSION: Through a multidisciplinary neuromuscular protocol, excellent clinical outcomes were achieved in patients with neuromuscular scoliosis and restrictive lung disease, with complication rates and length of stay significantly lower than previously published data. LEVEL OF EVIDENCE: IV.

Robotic-Assisted Versus Conventional Posterior Lumbar Fusion-An Analysis of 90-Day Complications and Readmissions.

OBJECTIVE: To evaluate medical and surgical complication rates between robotic-assisted versus conventional elective posterior lumbar fusions. METHODS: The Symphony Integrated DataVerse was queried using International Classification of Diseases, 10th Edition, Clinical Modification procedure codes to identify patients undergoing elective posterior lumbar fusions for degenerative spine pathologies between 2015 and 2018. International Classification of Diseases, 10th Edition, Clinical Modification procedure codes (8E0W4CZ, 8E0W0CZ, 8E0W3CZ) were used to identify patients undergoing a robotic-assisted spinal fusion. Outcome measures were 90-day medical and surgical complications, 1-year pseudarthrosis, and 1-year revision surgery rates. Multivariate logistic regression analyses were used to assess whether undergoing a robotic-assisted fusion (vs. conventional fusion) was associated with differences in wound complications, medical complications, pseudarthrosis, revision surgery, and readmissions within 90 days of surgery. RESULTS: A total of 39,387 patients undergoing elective posterior lumbar fusions were included in the cohort-of whom 245 (0.62%) patients underwent a robotic-assisted fusion. Multivariate analysis showed that robotic-assisted fusion (vs. conventional fusion) was not associated with significant differences in 90-day rates of wound complications (P = 0.299), urinary tract infections (P = 0.648), acute myocardial infarctions (P = 0.209), acute renal failure (P = 0.461), pneumonia (P = 0.214), stroke (P = 0.917), deep venous thrombosis (P = 0.562), pulmonary embolism (P = 0.401), and readmissions (P = 0.985). In addition, there were no significant differences in the 1-year rates of revision fusions (P = 0.316) and pseudarthrosis (P = 0.695). CONCLUSIONS: Patients who underwent a robotic-assisted fusion had similar rates of surgical and medical complications compared with those who underwent a conventional fusion. Further studies are warranted to better understand the future role of robots in spine surgery.

Evolving Surgical Management for Early-Onset Scoliosis in Spinal Muscular Atrophy Type 1 Given Improvements in Survival.

CASE: We present a case of an 18-month-old child with early-onset scoliosis in the setting of spinal muscular atrophy (SMA) type 1 whose rapidly progressive scoliosis is successfully managed with magnetic growing rods, the youngest age of implantation in a patient with SMA we are currently aware of. Technical challenges, complications, and outcome are described in this case presentation. CONCLUSION: Patients with SMA type 1 and early-onset scoliosis can be managed with growing-rod constructs given dramatic improvements in medical care that have expanded life expectancy.

What Is the Value of Undergoing Surgery for Spinal Metastases at Dedicated Cancer Centers?

BACKGROUND: The Alliance of Dedicated Cancer Centers is an organization of 11 leading cancer institutions and affiliated hospitals that are exempt from the Medicare prospective system hospital reimbursement policies. Because of their focus on cancer care and participation in innovative cancer treatment methods and protocols, these hospitals are reimbursed based on their actual billings. The perceived lack of incentive to meet a predetermined target price and reduce costs has spurred criticism of the value of cancer care at these institutions. The rationale of our study was to better understand whether dedicated cancer centers (DCCs) deliver high-value care for patients undergoing surgical treatment of spinal metastases. QUESTION/PURPOSE: Is there a difference in 90-day complications and reimbursements between patients undergoing surgical treatment (decompression or fusion) for spinal metastases at DCCs and those treated at nonDCC hospitals? METHODS: The 2005 to 2014 100% Medicare Standard Analytical Files database was queried using ICD-9 procedure and diagnosis codes to identify patients undergoing decompression (03.0, 03.09, and 03.4) and/or fusion (81.0X) for spinal metastases (198.5). The database does not allow us to exclude the possibility that some patients were treated with fusion for stabilization of the spine without decompression, although this is likely an uncommon event. Patients undergoing vertebroplasty or kyphoplasty for metastatic disease were excluded. The Medicare hospital provider identification numbers were used to identify the 11 DCCs. The study cohort was categorized into two groups: DCCs and nonDCCs. Although spinal metastases are known to occur among nonMedicare and younger patients, the payment policies of these DCCs are only applicable to Medicare beneficiaries. Therefore, to keep the study objective relevant to current policy and value-based discussions, we performed the analysis using the Medicare dataset. After applying the inclusion and exclusion criteria, we included 17,776 patients in the study, 6% (1138 of 17,776) of whom underwent surgery at one of the 11 DCCs. Compared with the nonDCC group, DCC group hospitals operated on a younger patient population and on more patients with primary renal cancers. In addition, DCCs were more likely to be high-volume facilities with National Cancer Institute designations and have a voluntary or government ownership model. Patients undergoing surgery for spinal metastases at DCCs were more likely to have spinal decompression with fusion than those at nonDCCs (40% versus 22%; p < 0.001) and had a greater length and extent of fusion (at least four levels of fusion; 34% versus 29%; p = 0.001). Patients at DCCs were also more likely than those at nonDCCs to receive postoperative adjunct treatments such as radiation (16% versus 13.5%; p = 0.008) and chemotherapy (17% versus 9%; p < 0.001), although this difference is small and we do not know if this meets a minimum clinically important difference. To account for differences in patients presenting at both types of facilities, multivariate logistic regression mixed-model analyses were used to compare rates of 90-day complications and 90-day mortality between DCC and nonDCC hospitals. Controls were implemented for baseline clinical characteristics, procedural factors, and hospital-level factors (such as random effects). Generalized linear regression mixed-modeling was used to evaluate differences in total 90-day reimbursements between DCCs and nonDCCs. RESULTS: After adjusting for differences in baseline demographics, procedural factors, and hospital-level factors, patients undergoing surgery at DCCs had lower odds of experiencing sepsis (6.5% versus 10%; odds ratio 0.54 [95% confidence interval 0.40 to 0.74]; p < 0.001), urinary tract infections (19% versus 28%; OR 0.61 [95% CI 0.50 to 0.74]; p < 0.001), renal complications (9% versus 13%; OR 0.55 [95% CI 0.42 to 0.72]; p < 0.001), emergency department visits (27% versus 31%; OR 0.78 [95% CI 0.64 to 0.93]; p = 0.01), and mortality (39% versus 49%; OR 0.75 [95% CI 0.62 to 0.89]; p = 0.001) within 90 days of the procedure compared with patients treated at nonDCCs. Undergoing surgery at a DCC (90-day reimbursement of USD 54,588 ± USD 42,914) compared with nonDCCs (90-day reimbursement of USD 49,454 ± USD 38,174) was also associated with reduced 90-day risk-adjusted reimbursements (USD -14,802 [standard error 1362] ; p < 0.001). CONCLUSION: Based on our findings, it appears that DCCs offer high-value care, as evidenced by lower complication rates and reduced reimbursements after surgery for spinal metastases. A better understanding of the processes of care adopted at these institutions is needed so that additional cancer centers may also be able to deliver similar care for patients with metastatic spine disease. LEVEL OF EVIDENCE: Level III, therapeutic study.

The Association of "U.S. News & World Report" Hospital Rankings and Outcomes Following Anterior Cervical Fusions: Do Rankings Even Matter?

STUDY DESIGN: Retrospective observational study. OBJECTIVE: The aim of this study was to evaluate whether there are any differences in outcomes and costs for elective one- to three-level anterior cervical fusions (ACFs) performed at US News and World Report (USNWR) ranked and unranked hospitals. SUMMARY OF BACKGROUND DATA: Although the USNWR rankings are advertised by media and are routinely used by patients as a guide in seeking care, evidence regarding whether these rankings are reflective of actual clinical outcome remains limited. METHODS: The 2010-2014 USNWR hospital rankings were used to identify ranked hospitals in "Neurosurgery" and "Orthopedics." The 2010-2014 100% Medicare Standard Analytical Files (SAF100) were used to identify patients undergoing elective ACFs at ranked and unranked hospitals. Multivariable logistic regression and generalized linear regression analyses were used to assess for differences in 90-day outcomes and costs between ranked and unranked hospitals. RESULTS: A total of 110,520 patients undergoing elective one- to three-level ACFs were included in the study, of which 10,289 (9.3%) underwent surgery in one of the 100 ranked hospitals. Following multivariate analysis, there were no significant differences between ranked versus unranked hospitals with regards to wound complications (1.2% vs. 1.1%; P = 0.907), cardiac complications (12.9% vs. 11.9%; P = 0.055), pulmonary complications (3.7% vs. 6.7%; P = 0.654), urinary tract infections (7.3% vs. 5.8%; P = 0.120), sepsis (9.3% vs. 7.9%; P = 0.847), deep venous thrombosis (1.9% vs. 1.3%; P = 0.077), revision surgery (0.3% vs. 0.3%; P = 0.617), and all-cause readmissions (4.7% vs. 4.4%; P = 0.266). Ranked hospitals, as compared to unranked hospitals, had a slightly lower odds of experiencing renal complications (7.0% vs. 4.9%; P = 0.047), but had significantly higher risk-adjusted 90-day charges (+$17,053; P < 0.001) and costs (+ $1695; P < 0.001). CONCLUSION: Despite the higher charges and costs of care at ranked hospitals, these facilities appear to have similar outcomes as compared to unranked hospitals following elective ACFs.Level of Evidence: 3.

Hospital network participation and outcomes following elective posterior lumbar fusions - are mergers effective?

BACKGROUND CONTEXT: Due to financial pressures associated with healthcare reforms, an increasing number of hospitals are now merging (or consolidating) into networks (or systems). However, it remains unclear how these mergers or network participations affect quality of care and/or costs. PURPOSE: The current study aims to evaluate the impact of hospital network participation on 90-day complications, charges, and costs following elective posterior lumbar fusions (PLFs). STUDY DESIGN: Retrospective review of a 100% national sample of Medicare claims from 2010 to 2014 (SAF100). STUDY SAMPLE: All Medicare-eligible patients undergoing elective 1-to-3 level PLFs for degenerative lumbar pathology from 2010 to 2014. OUTCOME MEASURES: Ninety-day complications, charges, and costs. METHODS: The 2010 to 2014 100% Medicare Standard Analytical Files (SAF100) was used to identify patients undergoing elective 1- to 3-level PLFs for degenerative lumbar pathology. The Dartmouth Atlas for Healthcare hospital-level data, which uses a combination of American Hospital Association and additional source data, was used to identify hospitals that were part of a network (or system) between 2010 and 2014. The study sample was divided into 2 cohorts (network hospitals and non-network hospitals) for analyses. Multivariate logistic regression models were used to compare differences in 90-day complications between network and non-network hospitals, while controlling for baseline demographics (age, gender, region, year of surgery, median household income, co-morbidity burden) and hospital-level characteristics (case volume, teaching status, urban/rural location, and hospital ownership). Generalized linear regression modeling was used to assess for differences in 90-day charges and costs. RESULTS: A total of 145,141 patients undergoing surgery in 2,186 hospitals were included in the study, out of which 107,919 (74.4%) underwent surgery in a network hospital (N=1,526). Network hospitals were more prevalent in the South or West regions of the United States. Patients in network hospitals had a median household income less than the 5th quintile. Network hospitals were also more likely to have a higher annual case volume of elective 1- to 3-level PLFs, greater number of beds, be located in an urban location, and have a voluntary/nonprofit or proprietary/profit ownership model. Multivariate analyses showed that even though patients undergoing surgery at network hospitals (vs non-network hospitals) had a slightly increased odds of 90-day cardiac complications (7.9% vs 7.4%, odds ratio [OR] 1.07 [95% confidence interval {CI} 1.02-1.12]; p=.010), thromboembolic complications (2.4% vs 2.2%, OR 1.12 [95% CI 1.01-1.20]; p=.025) and emergency department visits (16.4% vs 16.0%, OR 1.06 [95% CI 1.02-1.09]; p=.002), the differences would not be considered clinically significant. Despite a slight decrease in risk-adjusted 90-day reimbursements (-$272), the risk-adjusted 90-day charges were actually significantly higher (+$9,959; p<.001) at network hospitals. CONCLUSIONS: Even though hospitals that are part of a network do not appear to have significantly different complication rates following elective PLFs, they do have significantly higher risk-adjusted charges as compared to non-network hospitals. Further research is required to understand market-level changes induced by hospital mergers into networks.

Dropped Head Syndrome: A Systematic Review.

STUDY DESIGN: This study was a systematic review. OBJECTIVES: To reveal demographic factors, etiologies, response to treatment, and to propose a novel treatment algorithm for dropped head syndrome (DHS). SUMMARY OF BACKGROUND DATA: DHS is a rare condition defined by weakness of the cervical paraspinal muscles resulting in passively correctable flexion of the cervical spine. Patients present with neck pain, difficulty eating, and impaired horizontal gaze. Because of the rarity of DHS, a paucity of information exists with regard to demographics, etiology, and relative superiority of medical and surgical treatment. MATERIALS AND METHODS: We conducted a systematic literature review by searching PubMed for "dropped head syndrome," "chin on chest," "isolated neck extensor myopathy" (INEM), and "camptocephalia." Inclusion criteria were English-language articles that applied a specific treatment regimen with outcome data. A binomial logistic regression analysis was then performed to determine which covariates (age, sex, and treatments) were predictive of a positive response to treatment. RESULTS: A total of 129 patients were described in 74 studies. Mean age was 63.6 and 63% were female. More than two-thirds of all patients fell into just 4 diagnostic categories (isolated neck extensor myopathy, 31.8%; Parkinson's, 20.2%; myasthenia gravis, 12.4%; amyotrophic lateral sclerosis, 7.0%). Overall positive response to treatment was 64.3%; primary medical treatment (73.5%), immune suppression (78.9%), and a combination of both (87.5%). Surgery was 93.8% successful. A treatment algorithm focused on appropriate diagnosis, initial medical management, with surgical evaluation only after failure of medical treatment was proposed. CONCLUSIONS: Treatment for DHS starts with accurate diagnosis of the underlying etiology and is often associated with neuromuscular disease. A treatment algorithm for appropriate management of these patients was proposed. A trial of medical management and/or immunomodulators is warranted. Failing nonoperative management, surgery is predictive of a positive outcome. LEVEL OF EVIDENCE: Level V.

Indications for CT-Angiography of the Vertebral Arteries After Trauma.

STUDY DESIGN: Retrospective. OBJECTIVE: The purpose of this project is to identify factors that predict vertebral artery injury (VAI) in an effort to assess risks and benefits of computed tomography angiography (CT-A) of the neck in the trauma setting. We seek to develop guidelines for practitioners to stratify patients at medium/high risk of VAI from those who are at low risk. SUMMARY OF BACKGROUND DATA: VAI and blunt carotid injury (BCI) together comprise blunt cerebrovascular injury (BCVI). More is known about risk factors for BCI than for VAI, but the neurovascular complications associated with VAI are similarly disastrous. With increasing frequency, trauma providers are using CT-A to screen for BCVI; this test carries risks that include radiation exposure and nephrotoxicity, in addition to higher cost of treatment and longer hospital stay. METHODS: Trauma patients seen over 4 months at an urban, level 1 trauma were analyzed. BCVI screening was conducted in 144/1854 (7.77%) patients. Presence of VAI and several clinical characteristics were recorded. Univariate analysis and binomial logistic regression analysis were conducted at a 95% significance level. RESULTS: VAI was diagnosed in 0.49% of the study population. Univariate analysis determined six factors associated with positive VAI screening. Regression analysis showed four factors that independently predicted VAI: female sex, decreased Glasgow Coma Scale, cervical spine (c-spine) fracture, and concurrent BCI. A positive c-spine physical examination trended toward predicting VAI without achieving significance. CONCLUSION: Several independent predictors of VAI were identified. This study highlights the importance of identifying patients at a higher risk for VAI and indicating CT-A of the neck versus those who are at low risk and can be evaluated without undergoing advanced imaging, as CT-A appears unnecessary for most trauma patients. LEVEL OF EVIDENCE: 3.

A cadaveric investigation into the demographic and bony alignment properties associated with osteoarthritis of the patellofemoral joint.

BACKGROUND: Patellofemoral joint osteoarthritis is common, although circumstances dictating its evolution and pathogenesis remain unclear. Advances in surgical technique have improved the ability to modify long-bone alignment in the coronal, sagittal, and axial planes. However, to our knowledge, there is no significant long-term data available in regard to the relationship between anatomic alignment parameters most amenable to surgical modification and patellofemoral joint osteoarthritis. METHODS: Five-hundred and seventy-one cadaveric skeletons were obtained from the Hamann-Todd osteological collection. Mechanical lateral distal femoral angle, medial proximal tibial angle, tibial slope, femoral version, tibial torsion, the position of the tibial tubercle relative to the width of the tibial plateau, trochlear depth, and patellar size were measured using validated techniques. A previously published grading system for patellofemoral joint arthritis was used to quantify macroscopic signs of degenerative joint disease. RESULTS: Increasing age (standardized beta 0.532, p<0.001), female gender (standardized beta 0.201, p=0.002), and decreasing mechanical lateral distal femoral angle (standardized beta -0.128, p=0.025) were independent correlates of increased patellofemoral joint osteoarthritis. A relatively more laterally positioned tibial tubercle trended towards predicting patellofemoral joint osteoarthritis (standardized beta 0.080, p=0.089). CONCLUSIONS: These findings confirm that patellofemoral joint osteoarthritis is strongly associated with increasing age and female gender. Valgus alignment of the distal femur, a relatively more lateral location of the tibial tubercle, and a shallower trochlear grove appear to have modest effects on the development of patellofemoral joint osteoarthritis.