Sequential Enhancer Sequestration Dysregulates Recombination Center Formation at the IgH Locus.

Immunoglobulin heavy-chain (IgH) genes are assembled by DNA rearrangements that juxtapose a variable (VH), a diversity (DH), and a joining (JH) gene segment. Here, we report that in the absence of intergenic control region 1 (IGCR1), the intronic enhancer (Eµ) associates with the next available CTCF binding site located close to VH81X via putative heterotypic interactions involving YY1 and CTCF. The alternate Eµ/VH81X loop leads to formation of a distorted recombination center and altered DH rearrangements and disrupts chromosome conformation that favors distal VH recombination. Cumulatively, these features drive highly skewed, Eµ-dependent recombination of VH81X. Sequential deletion of CTCF binding regions on IGCR1-deleted alleles suggests that they influence recombination of single proximal VH gene segments. Our observations demonstrate that Eµ interacts differently with IGCR1- or VH-associated CTCF binding sites and thereby identify distinct roles for insulator-like elements in directing enhancer activity.

Impact of Compensated Cirrhosis Etiology on Postoperative Outcomes Following Total Knee Arthroplasty.

BACKGROUND: Cirrhotics often demonstrate worse outcomes than their non-cirrhotic counterparts following orthopedic surgery; however, there are limited arthroplasty-focused data on this occurrence. Additionally, variances in postoperative outcomes among the different etiologies of cirrhosis have not been well described. The aim of this study is to evaluate the effect compensated cirrhosis had on postoperative outcomes following elective total knee arthroplasty (TKA). METHODS: In total, 1,734,568 patients who underwent primary TKA from 2006 to 2013 were identified using the Medicare Claims Database. Patients were divided into those with a history of compensated cirrhosis and those with no history of liver disease. Subgroup analysis was performed based on the etiology of cirrhosis. Multivariate logistic regression was used to evaluate postsurgical outcomes of interest. RESULTS: Cirrhotic patients had higher risk of developing disseminated intravascular coagulation (odds ratio [OR] 2.76, P = .003), encephalopathy (OR 3.00, P < .001), and periprosthetic infection (OR 1.79, P < .001) compared to controls. Following subgroup analysis, alcoholic cirrhotics had high risk of periprosthetic infection (OR 2.12, P < .001), fracture (OR 3.28, P < .001), transfusion (OR 2.45, P < .001), and encephalopathy (OR 7.34, P < .001) compared to controls. Viral cirrhosis was associated with an increase in 90-day charges ($14,941, P < .001) compared to controls, while cirrhosis secondary to other causes was associated with few adverse outcomes compared to controls. CONCLUSION: Liver cirrhosis is an independent risk factor for increased perioperative morbidity and financial burden following TKA. Cirrhosis due to etiologies other than viral infections and alcoholism are associated with few adverse outcomes. Surgeons should be aware of these complications to properly optimize postoperative management.

Compensated Cirrhosis Is Associated With Increased Risk of Complications Following Total Hip Arthroplasty in a Large Medicare Database.

BACKGROUND: The aim of this study is to evaluate medical and surgical complications of liver cirrhosis patients following total hip arthroplasty (THA), with attention to different etiologies of cirrhosis and their financial burden following THA. METHODS: In total, 18,321 cirrhotics and 722,757 non-cirrhotics who underwent primary elective THA between 2006 and 2013 were identified from a retrospective database review. This cohort was further subdivided into 2 major etiologies of cirrhosis (viral and alcoholic cirrhosis) and other cirrhotic etiology. Cirrhotics were compared to non-cirrhotics for hospital length of stay, 90-day mean total charges and reimbursement, hospital readmission, and major medical and arthroplasty-specific complications. RESULTS: Cirrhosis was associated with increased rates of major medical complications (4.3% vs 2.4%; odds ratio [OR] 1.20, P < .001), minor medical complications, transfusion (3.4% vs 2.1%; OR 1.16, P = .001), encephalopathy, disseminated intravascular coagulation, and readmission (13.5% vs 8.6%; OR 1.18, P < .001) within 90 days. Cirrhosis was associated with increased rates of revision, periprosthetic joint infection, hardware failure, and dislocation within 1 year postoperatively (3.1% vs 1.6%; OR 1.37, P < .001). Cirrhosis independently increased hospital length of stay by 0.14 days (P < .001), and it independently increased 90-day charges and reimbursements by $13,791 (P < .001) and $1707 (P < .001), respectively. Viral and alcoholic cirrhotics had higher rates of 90-day and 1-year complications compared to controls-other causes only had higher rates of 90-day medical complications, encephalopathy, readmission, and 1-year revision, hardware failure, and dislocation compared to controls. CONCLUSION: Cirrhosis, especially viral and alcoholic etiologies, is associated with higher risk of early postoperative complications and healthcare utilization following elective THA.

Revision Joint Arthroplasty and Renal Transplant: A Matched Control Cohort Study.

BACKGROUND: There is little literature concerning clinical outcomes following revision joint arthroplasty in solid organ transplant recipients. The aims of this study are to (1) analyze postoperative outcomes and mortality following revision hip and knee arthroplasty in renal transplant recipients (RTRs) compared to non-RTRs and (2) characterize common indications and types of revision procedures among RTRs. METHODS: A retrospective Medicare database review identified 1020 RTRs who underwent revision joint arthroplasty (359 revision total knee arthroplasty [TKA] and 661 revision total hip arthroplasty [THA]) from 2005 to 2014. RTRs were compared to their respective matched control groups of nontransplant revision arthroplasty patients for hospital length of stay, readmission, major medical complications, infections, septicemia, and mortality following revision. RESULTS: Renal transplantation was significantly associated with increased length of stay (6.12 ± 7.86 vs 4.33 ± 4.29, P < .001), septicemia (odds ratio [OR], 2.52; 95% confidence interval [CI], 1.83-3.46; P < .001), and 1-year mortality (OR, 2.71; 95% CI, 1.51-4.53; P < .001) following revision TKA. Among revision THA patients, RTR status was associated with increased hospital readmission (OR, 1.23; 95% CI, 1.03-1.47; P = .023), septicemia (OR, 1.82; 95% CI, 1.41-2.34; P < .001), and 1-year mortality (OR, 2.65; 95% CI, 1.88-3.66; P < .001). The most frequent primary diagnoses associated with revision TKA and THA among RTRs were mechanical complications of prosthetic implant. CONCLUSION: Prior renal transplantation among revision joint arthroplasty patients is associated with increased morbidity and mortality when compared to nontransplant recipients.

Does Polycythemia Vera Increase Risk of Postoperative Complications Following Primary Total Joint Arthroplasty? A Retrospective Matched Control Cohort Study of 6932 Polycythemia Vera Patients.

BACKGROUND: There is sparsity of data on outcomes following joint arthroplasty among polycythemia vera (PV) patients. The aim of this study is to evaluate postoperative outcomes following primary total knee (TKA) and hip (THA) arthroplasty among PV patients. METHODS: A retrospective Medicare database review identified 6932 PV patients who underwent a primary total joint arthroplasty (4643 TKAs and 2289 THAs) from 2006 to 2013. A comparison of hospital length of stay, mortality, and the diagnosis of surgical site infections (SSIs), stroke, myocardial infarction, acute pulmonary embolism (PE), deep vein thrombosis (DVT), and other postoperative complications was made between PV patients undergoing TKA and THA and their respective matched control groups. RESULTS: PV was significantly associated with increased rates of acute PE (2.3% vs 1.6%; odds ratio [OR] 1.44, 95% confidence interval [CI] 1.17-1.75), DVT (4.2% vs 3.6%; OR 1.40, 95% CI 1.20-1.61, P < .001), postoperative hematoma (0.6% vs 0.4%; OR 1.57, 95% CI 1.03-2.28), and SSI (4.5% vs 3.6%; OR 1.25, 95% CI 1.08-1.44, P = .002) following TKA. Among PV patients who underwent a primary THA, PV was significantly associated with increased rate of acute PE (1.9% vs 1.4%; OR 1.40, 95% CI 1.01-1.88, P = .035), DVT (3.5% vs 2.6%; OR 1.32, 95% CI 1.04-1.66, P = .035), postoperative hematoma (1.1% vs 0.6%; OR 1.86, 95% CI 1.22-2.80), and 1-year mortality (2.2% vs 1.6%; OR 1.43, 95% CI 1.06-1.89, P = .016). CONCLUSION: PV was significantly associated with increased risk for DVT, PE, postoperative hematoma, SSI (TKA only), and 1-year mortality (THA only) following primary total joint arthroplasty.

Outcomes Following Revision Joint Arthroplasty Among Hemodialysis-Dependent Patients.

BACKGROUND: Hemodialysis (HD) dependence is known to impact the integrity of bone and has long been associated with metabolic bone disease and other adverse events postoperatively. The aim of this study is to analyze postoperative outcomes following revision hip and knee arthroplasty in hemodialysis-dependent (HDD) patients and to characterize the common indications for revision procedures among this patient population. METHODS: A total of 1779 HDD patients who underwent a revision joint arthroplasty (930 revision total knee arthroplasty [TKA] and 849 revision total hip arthroplasty [THA]) between 2005 and 2014 were identified from a retrospective database review. Our resulting study groups of revision TKA and THA HDD patients were compared to their respective matched control groups for hospital length of stay (LOS), 90-day mean total cost, hospital readmission, and other major medical and surgical complications. RESULTS: HD was significantly associated with increased LOS (7.7 ± 8.3 vs 4.8 ± 4.5; P < .001), mean 90-day total cost ($47,478 ± $33,413 vs $24,286 ± $21,472; P < .001), hospital readmission (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.96-2.58; P < .001), septicemia (OR, 3.18; 95% CI, 2.70-3.74; P < .001), postoperative infection (OR, 1.72; 95% CI, 1.50-1.98; P < .001), and mortality (OR, 3.99; 95% CI, 3.12-5.06; P < .001) following revision TKA. Among revision THA patients, HD was associated with increased LOS (9.4 ± 9.5 vs 5.7 ± 5.7; P < .001), mean 90-day total cost ($40,182 ± $27,082 vs $26,519 ± $22,856; P < .001), hospital readmission (OR, 2.33; 95% CI, 2.02-2.68; P < .001), septicemia (OR, 3.61; 95% CI, 3.05-4.27; P < .001), and mortality (OR, 3.55; 95% CI, 2.86-4.37; P < .001). CONCLUSION: HD remains a significant risk factor for increased LOS, mean total cost, hospital readmission, septicemia, and mortality following revision joint arthroplasty.

A Retrospective Database Review of the Indications, Complications, and Incidence of Subsequent Spine Surgery in 12,297 Spinal Cord Stimulator Patients.

STUDY DESIGN: Retrospective review. OBJECTIVE: To analyze the indications, incidence of minor and major complications, and rate of subsequent spinal surgery or revision after spinal cord stimulator (SCS) placement for degenerative spine disease. SUMMARY OF BACKGROUND DATA: Despite the application of SCS in various chronic pain conditions, there remains a growing debate on the efficacy and necessity of SCS in degenerative spine disease. METHODS: A nationally representative sample of Medicare patients who had an open (via laminectomy) SCS placement for degenerative spine disease between 2005 and 2014 were studied. Indications, complications, and the rate of subsequent spinal surgery within 90 days, one year, two years, and three years postoperatively were studied using Current Procedural Terminology (CPT) and International Classification of Diseases (ICD) codes. RESULTS: We included 12,297 SCS patients in our study cohort. The most common indications for SCS placement were postlaminectomy syndrome (25.2%) and chronic pain syndrome (20.2%). There was a 4.2 and 17.2% incidence of postoperative back or spine emergency department (ED) visits, and a 0.3 and 3.4% incidence of SCS electrode removal or reimplantation within 90 days and 1 year, respectively. Other reported surgical complications were wound infection (4.3%), hematoma (0.5%), and seroma (0.4%) at one year postoperatively. Within 90 days after SCS implantation, the rate of subsequent spine surgery or revision was 0.9%. This incidence was 7.1, 11.7, and 15.5% at one, two, and three years, respectively. CONCLUSIONS: In our retrospective analysis of Medicare patients, the most common indication for SCS implantation was postlaminectomy syndrome. Common postoperative complications included wound infection, and removal of SCS electrodes at one year postoperatively. About 17% patients had an ED visit for spine-related symptoms within one year of device implantation, and 15.5% underwent subsequent spinal decompression and/or fusion within 3 years after primary SCS placement.

Pedicle Subtraction Osteotomy Versus Multilevel Anterior Lumbar Interbody Fusion and Lateral Lumbar Interbody Fusion in the Treatment of Adult Spinal Deformity: Trends, Outcomes, and Cost.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of this study was to compare the outcomes of pedicle subtraction osteotomy (PSO) with multilevel anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) in posterior long-segment fusion. BACKGROUND: PSO and ALIF/LLIF are 2 techniques used to restore lumbar lordosis and correct sagittal alignment, with each holding its unique advantages and disadvantages. As there are situations where both techniques can be employed, it is important to compare the risks and benefits of both. PATIENTS AND METHODS: Patients aged 18 years or older who underwent PSO or multilevel ALIF/LLIF with posterior fusion of 7-12 levels and pelvic fixation were identified. 1:1 propensity score was used to match PSO and ALIF/LLIF cohorts for age, sex, and relevant comorbidities, including smoking status. Logistic regression was used to compare medical and surgical outcomes. Trends and costs were generated for both groups as well. RESULTS: ALIF/LLIF utilization in posterior long fusion has been steadily increasing since 2010, whereas PSO utilization has significantly dropped since 2017. PSO was associated with an increased risk of durotomy ( P < 0.001) and neurological injury ( P = 0.018). ALIF/LLIF was associated with increased rates of postoperative radiculopathy ( P = 0.005). Patients who underwent PSO had higher rates of pseudarthrosis within 1 and 2 years ( P = 0.015; P = 0.010), 1-year hardware failure ( P = 0.028), and 2-year reinsertion of instrumentation ( P = 0.009). Reoperation rates for both approaches were not statistically different at any time point throughout the 5-year period. In addition, there were no significant differences in both procedural and 90-day postoperative costs. CONCLUSIONS: PSO was associated with higher rates of surgical complications compared with anterior approaches. However, there was no significant difference in overall reoperation rates. Spine surgeons should select the optimal technique for a given patient and the type of lordotic correction required.

A Matched-Cohort Analysis of Outcomes in Patients with Hereditary Hemochromatosis After Anterior Cervical Discectomy and Fusion.

BACKGROUND: Hereditary hemochromatosis (HH) is a common autosomal recessive disorder. This disease affects gut iron transport, leading to iron overload, which affects immune function, coagulation mechanics, and bone health. Within the spine, HH contributes to decreased bone mineral density and accelerated intervertebral disc degeneration. The purpose of this study was to discover the differences in the rates of common 90-day postoperative complications and 1-year and 2-year surgical outcomes in patients with and without HH after anterior cervical discectomy and fusion (ACDF). METHODS: Using the PearlDiver database, patients with active diagnoses of HH before ACDF were matched to patients without HH using a 1:5 ratio on the basis of age, sex, body mass index, and comorbidities. Postoperative complications were assessed at 90 days, and 1-year and 2-year surgical outcomes were assessed. All outcomes and complications were analyzed using multivariate logistic regression with significance achieved at P < 0.05. RESULTS: Patients with HH had significantly higher rates of 1-year and 2-year reoperation rates compared with patients without HH (29.19% vs. 3.94% and 37.1% vs. 5.93%, respectively; P < 0.001). The rates of 90-day postoperative complications significantly increased in patients with HH including dysphagia, pneumonia, cerebrovascular accident, deep vein thrombosis, acute kidney injury, urinary tract infection, hyponatremia, surgical site infection, iatrogenic deformity, emergency department visit, and hospital readmission. CONCLUSIONS: Patients with HH undergoing ACDF showed increased 90-day postoperative complications and significantly increased rates of 1-year and 2-year reoperation compared with patients without HH. These findings suggest that iron overload may contribute to adverse outcomes in patients with HH undergoing 1-level and 2-level ACDF.

Carbon fiber lumbopelvic reconstruction following sacral giant cell tumor resection: illustrative case.

BACKGROUND: The use of carbon fiber or polyetheretherketone spine constructs has proven to be a safe and effective alternative to standard metal alloy. The mechanical properties of carbon fiber while unique provide a construct that is comparable in strength to previous titanium-based constructs and have additionally shown greater fatigue resistance. These constructs have been especially useful for the mechanical stabilization of the spine following tumor resection. The subsequent interference seen when imaging a patient with a traditional metallic construct is reduced and allows for improved tumor surveillance after the procedure, and a more accurate delivery of radiotherapy when indicated. OBSERVATIONS: This case report details the treatment of a 25-year-old female diagnosed with a sacral giant cell tumor. The authors discuss the use of a carbon fiber-reinforced polyetheretherketone for lumbopelvic reconstruction. LESSONS: Carbon fiber-reinforced polyetheretherketone with its radiolucency and rigidity is a reliable option for complex spinal reconstruction after tumor resection.

Effect of Celiac Disease on Outcomes After Posterior Lumbar Fusion: A Matched Cohort Study.

OBJECTIVE: The purpose of this study was to analyze if celiac disease (CD) is associated with increased postoperative complications following single-level posterior lumbar fusion (PLF). METHODS: A retrospective database review was performed using the PearlDiver dataset. The study population included all patients older than 18 years who underwent elective PLF with diagnosis of CD using International Classification of Diseases (ICD) and Current Procedural Terminology (CPT) codes. Study patients were compared with controls for 90-day medical complications and 2-year surgical complications including 5-year reoperation rates. A multivariate logistic regression was used to determine the independent effect of CD on the postoperative outcomes. RESULTS: A total of 909 patients with CD and 4483 patients in the matched control group who underwent primary single-level PLF were included in this study. CD patients had a significantly increased risk of 90-day emergency department (ED) visit (OR 1.28; P = 0.020). CD patients also demonstrated higher rates of 2-year pseudarthrosis and instrument failure, but they were statistically comparable (P > 0.05). There was no difference in 5-year reoperation rate. There were also no significant differences in 90-day medical complication rate and 2-year surgical complication rate between the two groups. In addition, there were no differences in procedure cost and 90-day cost. CONCLUSIONS: For CD patients undergoing PLF, the current study demonstrated increased rate of 90-day ED visit. Our findings may be useful for patient counseling and surgical planning for those with this condition.

Outcomes Following Anterior Cervical Discectomy and Fusion in Patients With Ehlers-Danlos Syndrome.

STUDY DESIGN: Retrospective database analysis. OBJECTIVES: To study postoperative complication rates following anterior cervical discectomy and fusion (ACDF) in patients with Ehlers-Danlos syndrome (EDS) compared with patients without EDS. METHODS: The Mariner database was utilized to identify patients with EDS undergoing one or two level anterior cervical discectomy and fusion (ACDF). Postoperative short-term outcomes assessed included medical complications, readmissions, and ED-visits within 90 days of surgery. Additionally, surgical complications including wound complications, surgical site infection, one- and two-year anterior revision along with posterior revision, pseudarthrosis, and hardware failure within 2 years were assessed. Multivariate logistic regression was used to adjust for demographic variables, comorbidities and number of levels operated on. RESULTS: The present study identified 533 patients in the EDS group and 2634 patients in the matched control group. EDS patients undergoing ACDF are at an increased risk for 90-day major medical complications (OR 3.31; P < .001). EDS patients were also found to be associated with surgical complications including wound complications (OR 2.94; P < .001), surgical site infection (OR 8.60; P < .001) within 90 days, pseudarthrosis (OR 2.33; P < .001), instrument failure (OR 4.03; P < .001), anterior revision (OR 22.87; P < .001), and posterior revision (OR 3.17; P < .001) within 2 years. CONCLUSIONS: EDS is associated with higher rates of both medical and surgical complications following ACDF. Spine surgeons should be cognizant of the increased risks in this population to provide appropriate preoperative counseling and enhanced perioperative medical management.

Improvement of postural stability and gait velocity after cervical decompression surgery in patients with cervical spondylotic myelopathy.

OBJECTIVE: Cervical spondylotic myelopathy (CSM) is a progressive degenerative condition that can lead to significant neurological deficits, including gait instability. Biomechanical alterations of gait and its various components are poorly understood. The goal of the current study was to determine how spatiotemporal gait parameters, as well as postural and dynamic stability, change after surgery in CSM patients. METHODS: A total of 47 subjects were included, with 23 test subjects and 24 controls. Baseline measurements were made for both cohorts. In the CSM cohort, repeat measurements were made at 3 and 6 months postoperatively. To record spatiotemporal and dynamic stability parameters, subjects performed walking trials over force plates on a 15-m runway. To assess postural stability, standing balance trials were conducted on a floor-mounted force plate. Three-dimensional motion analysis cameras and gait modeling software were used to quantify and visually represent results. Statistical analysis was completed using repeated-measures ANOVA and paired t-tests. Significance was set at p < 0.05. RESULTS: CSM patients had significantly increased gait velocity at the 6-month follow-up (mean 0.948 ± 0.248 m/sec/leg length) versus baseline (mean 0.852 ± 0.257 m/sec/leg length) (p = 0.039). The tilted ellipse area was significantly decreased at the 6-month follow-up compared with baseline (mean 979.8 ± 856.7 mm2 vs 598.0 ± 391.1 mm2, p = 0.018). Angular momentum excursion was not significantly different between baseline and the 3- and 6-month follow-ups. CONCLUSIONS: CSM patients displayed significant improvement in gait velocity and postural stability parameters after decompressive surgery. Dynamic stability parameters did not change significantly during the study period.

Penicillin Allergy in Spine Surgery: Increased Rates of Sepsis, Emergency Room Visits, and Readmission.

OBJECTIVE: To determine if a penicillin allergy is an independent risk factor for poor outcomes after anterior cervical discectomy and fusion (ACDF) and posterior lumbar fusion (PLF). METHODS: A retrospective database review was performed using the PearlDiver data set. The study population included all patients younger than 85 years who underwent elective PLF or ACDF with diagnosis of penicillin allergy using International Classification of Diseases codes. Study patients were compared with controls for 90-day complications and 1-year reoperation rates. A multivariate logistic regression was used to determine the independent effect of penicillin allergy on the postoperative outcomes. RESULTS: PLF cohort multivariate analysis showed that patients with a penicillin allergy had a significantly increased risk of sepsis (2.6% vs. 2.0%; P = 0.020), urinary tract infection (10.8% vs. 8.4%; P < 0.001), emergency room visits (27.3% vs. 20.2%; P < 0.001), and readmissions (9.6% vs. 6.4%; P < 0.001) within 90 days index of surgery. Similarly, the ACDF cohort multivariate analysis showed that a penicillin allergy was associated with an increased risk of sepsis (1.8% vs. 1.1%; P < 0.001), emergency room visits (27.2% vs. 20.7%; P < 0.001), and readmissions (6.8% vs. 5.6%; P = 0.003) within 90 days index of surgery. CONCLUSIONS: The present study found that a reported penicillin allergy is associated with an increase in sepsis, urinary tract infection, emergency room visit, and readmission postoperatively within 90 days after PLF and ACDF. The findings can help physicians provide patients with more comprehensive preoperative counseling in the setting of patient-reported penicillin allergy.

Anterior cervical discectomy and fusion in patients with preexisting dementia: Increased medical complications, costs, and 90-day readmissions.

STUDY DESIGN: Retrospective-Cohort INTRODUCTION: Dementia is among the most common health concerns for the aging population, characterized by steep cognitive decline and subsequent loss of independence. Limited orthopedic literature examines the influence that dementia has on patients undergoing elective spinal surgeries. METHODS: Employing the PearlDriver Database, a study population consisting of patients who underwent primary elective ACDF with a prior diagnosis of dementia were selected using Internal Classification Disease-9 (ICD) and ICD-10 codes. Patients with a history of trauma, infection, or malignancy were excluded. Patients with dementia were compared to matched controls via logistical regression accounting for patient demographics, medical comorbidities and levels operated on. Patients were assessed for 90-day outcomes including medical complications, emergency department visits, readmissions, one-year reoperation, hospital length of stay (LOS) and total operative hospitalization costs, and 90-day postoperative cost. RESULTS: There were 4104 patients in the dementia group and 20,269 patients in the matched control group who underwent primary ACDF. Multivariate analysis showed that patients with dementia undergoing ACDF were associated with increased 90-day major and minor medical complications (p < 0.001). Patients with dementia were also associated with an increased risk of dysphagia (p < 0.001), 90-day ER visits(p < 0.001), 90-day readmissions(p < 0.001), and increased LOS(p < 0.001) following ACDF compared to the control group. Additionally, both total hospitalization costs and 90-day postoperative costs were higher in the dementia cohort(p < 0.001). CONCLUSION: Preoperative dementia diagnosis in patients undergoing ACDF is associated with increased number of readmissions, hospitalization and 90-day costs, and postoperative medical complications.

No Difference in Two-Year Revisions Between Hybrid Fusion and Two-Level Anterior Discectomy and Fusion: A National Database Study.

STUDY DESIGN: Retrospective Cohort. OBJECTIVE: This study utilized a large national database to compare two-year revision rates, in addition to complications and costs, of hybrid surgery (HS) compared to two-level anterior cervical discectomy and fusion (ACDF). METHODS: This study used the PearlDiver Mariner dataset selecting for patients aged 18 and older who had at least 90-day active longitudinal follow-up who underwent two-level ACDF or two-level Hybrid surgery (single level ACDF and single level CDA). Patients with prior spinal trauma, infection, cancer, or posterior fusion were excluded. Primary outcomes measures were 90-day major and minor medical complications, ED visits, readmissions, as well as two-year revisions. Patients were also assessed for postoperative dysphagia, incidental durotomy, vascular injury, 90-day surgical site, and implant complications. Additionally, hospitalization and postoperative costs were evaluated. RESULTS: There were 4570 two-level ACDF surgeries and 888 hybrid surgeries. After matching the cohorts, no statistical differences in demographics were found. There were no differences in reoperation rates at all measured time points nor 2-year complications. HS had a lower incidence of major (1.6% vs 3.1%, P = .003) and minor complications (3.0% vs 4.6%, P = .009) than ACDF. 90-day readmission was lower in the HS cohort (2.8% vs 4.2%), P = .024. HS was associated with reduced hospitalization costs -$2614 (-$3916 to -$904, P < .001). 3516 patients had ACDF, and 699 had HS with at least 2 years of follow-up. CONCLUSION: Hybrid surgery is a safe and effective surgical treatment for cervical disease in appropriately selected patients.

Prevalence of Osteoporosis Treatment and Its Effect on Post-Operative Complications, Revision Surgery and Costs After Multi-Level Spinal Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To study the prevalence of pre-operative osteoporosis treatment, and its effect on risk of ORC, revision surgery and costs in osteoporotic patients undergoing ≥3-level spinal fusion for degenerative pathology. METHODS: Patients and procedures of interest were included using International Classification of Diseases (ICD) and Current Procedural Terminology (CPT) coding. Our outcome measures were ORC at 1-year post-operatively and included instrumentation complications, pathological fracture, and revision surgery. Kaplan-Meier survival curves and Cox proportional hazards analysis was done to study the effect of osteoporosis treatment on risk of ORC. RESULTS: We included a total of 849 patients with documented osteoporosis undergoing ≥3-level spinal fusion. White (85.6%), female (82.7%), and 60-79 years of age (79.9%) was the most common demographic. Of entire cohort, 121(14.3%) were on osteoporosis treatment prior to spinal fusion. Of treated patients, 52/121 (43.0%) had continued prescriptions at 1 year post-operatively. Treated patients and not-treated patients had 1-year ORC incidence of 9.1% and 15.0%, respectively. The average 1-year reimbursement/patient for managing ORC was $3,053 (treated) and $21,147 (not-treated). On adjusted cox analysis, pre-operative osteoporosis treatment was associated with a lower risk of ORC (HR: 0.53, 95% CI: 0.28-0.99, p = 0.04). CONCLUSIONS: Pre-operative osteoporosis treatment is associated with lower risk of ORC and revision surgery at 1-year after ≥3-level spinal fusion. There is a low incidence of osteoporosis treatment prior to spinal fusion, and subsequently a low rate of treatment continuation after surgery. These findings highlight the need for heightened awareness, patient education and management of osteoporosis before elective multi-level spinal fusion.

Evaluation of Gait and Functional Stability in Preoperative Cervical Spondylotic Myelopathy Patients.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: The aim of this study was to 1) determine postural stability and spatiotemporal gait parameters and 2) characterize dynamic stability and variances in angular momentum (AM) of preoperative cervical spondylotic myelopathy (CSM) patients compared with healthy controls. SUMMARY OF BACKGROUND DATA: CSM is the most common cause of spinal cord dysfunction in the world and can lead to significant functional deficits including proprioception and gait disturbances. Biomechanical feedback mechanisms compensating for these deficits, specifically AM regulation, have remained largely unexplored. METHODS: Fifty-six subjects: 32 preoperative Nurick grade 2 or 3 CSM patients and 24 controls were included. Standing balance trials were performed on a single force plate, while walking trials were conducted at self-selected pace over a 15 m runway and a series of five force plates. All trials were recorded with three-dimensional motion analysis cameras and gait modeling software was utilized to calculate stability, spatiotemporal gait parameters, and joint kinematics. RESULTS: Tilted ellipse area, a measure of center of pressure variance and postural stability, was significantly greater among CSM patients (847.54 ±â€Š764.33 mm2vs. 258.18 ±â€Š103.35 mm2, P < 0.001). These patients had two times as much variance medial-lateral (72.12 ±â€Š51.83 mm vs. 29.15 ±â€Š14.95 mm, P = 0.001) and over three times as much anterior-posterior (42.25 ±â€Š55.01 mm vs. 9.17 ±â€Š4.83 mm, P = 0.001) compared with controls. Spatiotemporal parameters indicated that the CSM patients tending to have slower, shorter, and wider gait compared with controls, while spending greater amount of time in double support. Compensatory AM among CSM patients was significantly increased in all three anatomic planes, where whole-body AM was approximately double that of controls (0.057 ±â€Š0.034 vs. 0.023 ±â€Š0.006), P < 0.001). CONCLUSION: Preoperative CSM patients showed significant alterations in spatiotemporal gait parameters and postural stability compared with controls, consistent with prior literature. Likewise, angular momentum analysis demonstrates that these patients have globally increased body excursion to maintain dynamic balance.Level of Evidence: 3.

Increasing Cost Efficiency in Adult Spinal Deformity Surgery: Identifying Predictors of Lower Total Costs.

STUDY DESIGN: Retrospective study of a prospective multicenter database. OBJECTIVE: The purpose of this study was to identify predictors of lower total surgery costs at 3 years for adult spinal deformity (ASD) patients. SUMMARY OF BACKGROUND DATA: ASD surgery involves complex deformity correction. METHODS: Inclusion criteria: surgical ASD (scoliosis ≥20°, sagittal vertical axis [SVA] ≥5 cm, pelvic tilt ≥25°, or thoracic kyphosis ≥60°) patients >18 years. Total costs for surgery were calculated using the PearlDiver database. Cost per quality-adjusted life year was assessed. A Conditional Variable Importance Table used nonreplacement sampling set of 20,000 Conditional Inference trees to identify top factors associated with lower cost surgery for low (LSVA), moderate (MSVA), and high (HSVA) SRS Schwab SVA grades. RESULTS: Three hundred sixtee of 322 ASD patients met inclusion criteria. At 3-year follow up, the potential cost of ASD surgery ranged from $57,606.88 to $116,312.54. The average costs of surgery at 3 years was found to be $72,947.87, with no significant difference in costs between deformity groups (P > 0.05). There were 152 LSVA patients, 53 MSVA patients, and 111 HSVA patients. For all patients, the top predictors of lower costs were frailty scores <0.19, baseline (BL) SRS Activity >1.5, BL Oswestry Disability Index <50 (all P < 0.05). For LSVA patients, no history of osteoporosis, SRS Activity scores >1.5, age <64, were the top predictors of lower costs (all P < 0.05). Among MSVA patients, ASD invasiveness scores <94.16, no past history of cancer, and frailty scores <0.3 trended toward lower total costs (P = 0.071, P = 0.210). For HSVA, no history of smoking and body mass index <27.8 trended toward lower costs (both P = 0.060). CONCLUSION: ASD surgery has the potential for improved cost efficiency, as costs ranged from $57,606.88 to $116,312.54. Predictors of lower costs included higher BL SRS activity, decreased frailty, and not having depression. Additionally, predictors of lower costs were identified for different BL deformity profiles, allowing for the optimization of cost efficiency for all patients.Level of Evidence: 3.

Differences in 30-day complications associated with total ankle arthroplasty and ankle arthrodesis: A matched cohort study.

BACKGROUND: The objective of this study was to identify whether total ankle arthroplasty (TAA) was associated with greater risk for 30-day complications and/or greater financial burden in comparison to ankle arthrodesis (AA). METHODS: The PearlDiver Patient Records Database was queried to identify all patients who underwent an arthroscopic/open AA or TAA from 2006 to 2013. The two cohorts were then matched in a 1:1 manner to control for comorbidities and demographics. Postoperative complications were compared between the two cohorts, in addition to the associated costs with respect to each procedure. RESULTS: No significant differences in risk for postoperative complications were noted between the two procedures with the numbers available. Significant differences were demonstrated in total length of hospital stay (LOS), with a mean of 2.13 days for the TAA cohort and 2.42 days for the AA cohort (p < 0.001). Higher mean total hospital costs were noted for TAA (x¯ = $62,416.62) compared to AA (x¯ = $37,737.43, p < 0.001); however, TAA was associated with a higher mean total reimbursement (x¯ = $12,254.43) than AA (x¯ = $7915.72, p < 0.001). CONCLUSION: With no notable differences in 30-day complication rates, TAA remains a viable alternative to AA in the appropriately selected patient and provides the ability to preserve tibiotalar motion resulting in superior functional scores. Additionally, TAA demonstrated higher total costs to implant, but also greater reimbursement, in line with the recent literature suggesting TAA to be a cost-effective alternative to AA. LEVEL OF EVIDENCE: III Retrospective study.