Lumbar fusion during the COVID-19 pandemic: greater rates of morbidity and longer procedures.

Background: The coronavirus disease 2019 (COVID-19) pandemic has altered the standard of care for spine surgery in many ways. However, there is a lack of literature evaluating the potential changes in surgical outcomes and perioperative factors for spine procedures performed during the pandemic. In particular, no large database study evaluating the impact of the COVID-19 pandemic on spine surgery outcomes has yet been published. Therefore, the aim of this study was to evaluate the impact of the COVID-19 pandemic on perioperative factors and postoperative outcomes of lumbar fusion procedures. Methods: This retrospective cohort study utilized the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, which was queried for all adult patients who underwent primary lumbar fusion in 2019 and 2020. Patients were grouped into cohorts based on 2019 (pre-pandemic) or 2020 (intra-pandemic) operation year. Differences in 30-day readmission, reoperation, and morbidity rates were evaluated using multivariate logistic regression. Differences in total relative value units (RVUs), RVUs per minute, and total operation time were evaluated using quantile (median) regression. Odds ratios (OR) for length of stay were estimated via negative binomial regression. Results: A total of 27,446 patients were included in the analysis (12,473 cases in 2020). Unadjusted comparisons of outcomes revealed that lumbar fusions performed in 2020 were associated with higher rates of morbidity, pneumonia, bleeding transfusions, deep venous thrombosis (DVT), and sepsis. 2020 operation year was also associated with longer length of hospital stay, less frequent non-home discharge, higher total RVUs, and higher RVUs per minute. After adjusting for baseline differences in regression analyses, the differences in bleeding transfusions, length of stay, and RVUs per minute were no longer statistically significant. However, operation year 2020 independently predicted morbidity, pneumonia, DVT, and sepsis. In terms of perioperative variables, operation year 2020 predicted greater operative time, non-home discharge, and total RVUs. Conclusions: Lumbar fusion procedures performed amidst the COVID-19 pandemic were associated with poorer outcomes, including higher rates of morbidity, pneumonia, DVT, and sepsis. In addition, surgeries performed in 2020 were associated with longer operative times and less frequent non-home discharge disposition.

Association between muscle health and patient-reported outcomes after lumbar microdiscectomy: early results.

BACKGROUND CONTEXT: Poor muscle health has been implicated as a source of back pain among patients with lumbar spine pathology. Recently, a novel magnetic resonance imaging (MRI)-based lumbar muscle health grade was shown to correlate with health-related quality of life scores. However, the impact of muscle health on postoperative functional outcomes following spine surgery remains to be investigated. PURPOSE: To determine whether muscle health grade measured by preoperative psoas and paralumbar muscle cross-sectional areas impact the achievement of minimal clinically important difference (MCID) following lumbar microdiscectomy. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: Consecutive patients who underwent 1-level lumbar microdiscectomy in a single institution between 2017 and 2021. OUTCOME MEASURES: Rate of MCID achievement, time to MCID achievement, PROMs including Oswestry Disability Index (ODI), visual analog scale for back pain (VAS back), VAS leg, Short Form 12 Physical Component Summary (SF-12 PCS), SF-12 Mental Component Summary (SF-12 MCS), and Patient Reported Outcomes Measurement Information System Physical Function (PROMIS PF). METHODS: Two previously validated methods for muscle health grading were applied. Axial T2 MRI were analyzed for muscle measurements. The psoas-based method utilized the normalized total psoas area (NTPA), which is the psoas cross-sectional area divided by the square of patient height (mm2/m2). Patients were divided into low and high NTPA groups based on sex-specific lowest quartile NTPA thresholds. The paralumbar-based method incorporated the paralumbar cross-sectional area normalized by body mass index (PL-CSA/BMI) and Goutallier classification. Score of 1 was added for either PL-CSA/BMI >130 or Goutallier class of ≤2. "Good" muscle health was defined as score of 2, and "poor" muscle health was defined as score of 0 to 1. Prospectively collected PROMs were analyzed at 2-week, 6-week, 3-month, 6-month, 1-year, and 2-year postoperative timepoints. The rate of and time to MCID achievement were compared among the cohorts. Bivariate analyses were performed to assess for correlations between psoas/paralumbar cross-sectional areas and change in PROM scores from baseline. RESULTS: The total cohort included 163 patients with minimum follow-up of 6 months and mean follow-up of 16.5 months. 40 patients (24.5%) were categorized into the low NTPA group, and 55 patients (33.7%) were categorized into the poor paralumbar muscle group. Low NTPA was associated with older age, lower BMI, and greater frequencies of Charlson Comorbidity Index (CCI) ≥1. Poor paralumbar muscle health was associated with older age, female sex, higher BMI, and CCI ≥1. There were no differences in rates of MCID achievement for any PROMs between low versus high NTPA groups or between poor versus good paralumbar groups. Low NTPA was associated with longer time to MCID achievement for ODI, VAS back, VAS leg, and SF-12 MCS. Poor paralumbar muscle health was associated with longer time to MCID achievement for VAS back, VAS leg, and SF-12 PCS. NTPA negatively correlated with change in VAS back (6-week, 12-week) and VAS leg (6-month). PL-CSA/BMI positively correlated with change in PROMIS-PF at 3 months follow-up. CONCLUSIONS: Among patients undergoing lumbar microdiscectomy, patients with worse muscle health grades achieved MCID at similar rates but required longer time to achieve MCID. Lower NTPA was weakly correlated with larger improvements in pain scores. PL-CSA/BMI positively correlated with change in PROMIS-PF. Our findings suggest that with regards to functional outcomes, patients with worse muscle health may take longer to recuperate postoperatively compared to those with better muscle health.

Do preoperative clinical and radiographic characteristics impact patient outcomes following one-level minimally invasive transforaminal lumbar interbody fusion based upon presenting symptoms?

BACKGROUND CONTEXT: Patients undergoing minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) frequently present with lower extremity neurologic symptoms with or without associated lower back pain. While symptomatic improvement of leg and back pain has been reported, the resolution of back pain when it is a predominant presenting symptom remains underreported following MI-TLIF. PURPOSE: The purpose of this study was to compare clinical outcomes at 1 year of patients undergoing MI-TLIF with lower extremity neurologic symptoms with and without a significant component of back pain. STUDY DESIGN: A retrospective review of prospectively collected data from a single surgeon surgical database from 2017 to 2019 was performed. PATIENT SAMPLE: Fifty one patients undergoing MI-TLIF. OUTCOME MEASURES: Self-reported measures included the Oswestry Disability Index (ODI), Visual analog scale back pain (VAS-back), and VAS leg pain (VAS-leg). METHODS: Patients were divided into two groups: Leg Pain Predominant (patients reported greater than 50% leg pain upon presentation) and Back Pain Predominant (patients reported 50% or greater back pain). Multivariate analysis was performed to determine differences between groups based upon any significantly baseline characteristics. RESULTS: Preoperative demographic and radiographic outcomes were similar between the two groups. Both groups demonstrated significant improvement in ODI, VAS-Back and VAS-leg at 1-year postoperatively. On multivariate analysis, there were differences in ODI at 1-year, 1-year back pain, and 1-year leg pain between groups with those who initially presented with leg pain having a lower ODI, VAS Back, and VAS leg. Patients who presented with predominantly leg pain were more likely to meet minimal clinically important difference (MCID) criteria for ODI and VAS-back compared to those with predominantly back pain. CONCLUSION: Following MI-TLIF, patients with lower extremity neurologic symptoms with and without a significant component of back pain have improvements in back pain, leg pain, and ODI regardless of their primary presenting pain complaint; however, patients who presented with predominantly leg pain were more likely to meet MCID criteria for improvement in their back pain and ODI score.

Fusion rate for stand-alone lateral lumbar interbody fusion: a systematic review.

BACKGROUND: Lateral lumbar interbody fusion (LLIF) is used to treat multiple conditions, including spondylolisthesis, degenerative disc disorders, adjacent segment disease, and degenerative scoliosis. Although many advocate for posterior fixation with LLIF, stand-alone LLIF is increasingly being performed. Yet the fusion rate for stand-alone LLIF is unknown. PURPOSE: Determine the fusion rate for stand-alone LLIF. STUDY DESIGN: Systematic review. METHODS: We queried Cochrane, EMBASE, and MEDLINE for literature on stand-alone LLIF fusion rate with a publication cutoff of April 2020. LLIF surgery was considered stand-alone when not paired with supplemental posterior fixation. Cohort fusion rate differences were calculated and tested for significance (p<0.05). All reported means were pooled. RESULTS: A total of 2,735 publications were assessed. Twenty-two studies met inclusion criteria, including 736 patients and 1,103 vertebral levels. Mean age was 61.7 years with BMI 26.5 kg/m2. Mean fusion rate was 85.6% (range, 53.0%-100.0%), which did not differ significantly by number of levels fused (1-level, 2-level, and ≥3-level). Use of rhBMP-2 was reported in 39.3% of subjects, with no difference in fusion rates between studies using rhBMP-2 (87.7%) and those in which rhBMP-2 was not used (83.9%, odds ratio=1.37, p=0.448). Fusion rate did not differ with the addition of a lateral plate, or by underlying diagnosis. All-complication rate was 42.2% and mean reoperation rate was 11.1%, with 2.3% reoperation due to pseudarthrosis. Of the studies comparing stand-alone to circumferential fusion, pooled fusion rate was found to be 80.4% versus 91.0% (p=0.637). CONCLUSIONS: Stand-alone LLIF yields high fusion rates overall. The wide range of reported fusion rates and lower fusion rates in studies involving subsequent surgical reoperation highlights the importance of proper training in this technique and employing a rigorous algorithm when indicating patients for stand-alone LLIF. Future research should focus on examining risk factors and patient-reported outcomes in stand-alone LLIF.

Assessment of a rabbit posterolateral spinal fusion using movement between vertebrae: a modification of the palpation exam for quantifying fusions.

BACKGROUND: Manual palpation of rabbit spine levels has been used to assess fusion status. This method of testing is subject to inter-observer differences in assessment. We attempted to quantify fusion based on the amount of movement between rabbit vertebrae at the level of fusion. METHODS: Rabbits were divided into three groups. The first underwent a sham surgery; the second underwent a unilateral spinal fusion; and the third underwent a bilateral spinal fusion. All groups were sacrificed at either 5- or 10-week post-procedure. Each spine was tested for fusion using standard manual palpation techniques. The spines were also placed on a specially designed apparatus and moved through 10°, 20°, and 30° of extension/flexion. RESULTS: Out of 10 rabbits, 2 underwent sham surgery, 2 underwent a fusion procedure at L4-L5 and 6 underwent a fusion at L5-L6. We only included rabbits that underwent a L5-L6 fusion surgery. Our apparatus did not always rotate the spine the intended amount with up to 30% error. When rabbits graded as fused were compared to sham rabbits, there was a trend towards reduction in percent of overall measured angle within the fused group as compared to the sham group (8.77% vs. 13.84%, P=0.14). CONCLUSIONS: Our model attempted to quantify the amount of displacement between vertebrae during the manual palpation exam. There is a trend towards reduced measured angle between vertebrae between fused and non-fused spines and no statistically significant difference in overall measured angle between unilaterally and bilaterally fused spines.

Current state of minimally invasive spine surgery.

Over the past two decades, minimally invasive surgical approaches have become increasingly feasible, efficient and popular for the management of a wide range of spinal disorders, with a growing body of research demonstrating numerous advantages of these techniques over the traditional open approach. In this article, we review the technologies and innovations that are expanding the horizon of minimally invasive spine surgery (MISS), and highlight high-quality peer-reviewed literature in the past year that expands our knowledge and understanding of indications, advantages and limitations of MISS.

The rate of fusion for stand-alone anterior lumbar interbody fusion: a systematic review.

BACKGROUND: Anterior lumbar interbody fusion (ALIF) has been used for treatment of a variety of spinal conditions including degenerative disc disorders and low-grade spondylolisthesis. Expected fusion rate of stand-alone ALIF constructs is currently unclear. The aim of this study was to examine the fusion rate for ALIF without supplemental posterior fusion or instrumentation (stand-alone ALIF). METHODS: We queried the MEDLINE, COCHRANE, and EMBASE databases for all literature related to spine fusion rates using a stand-alone ALIF procedure with a publication cutoff date of July 19, 2018. Supplementary combinations of search terms included spine, fusion, fixation, rate(s), and arthrodesis. ALIF surgery was considered stand-alone when not paired with supplemental posterior fusion or posterior spinal instrumentation. Nonhuman and non-English publications were excluded. Cohort fusion rate differences were calculated using Student t test with significance assigned if p value was less than .05. RESULTS: Title and abstract level review required assessing 840 unique publications. Across the 55 studies that met the inclusion criteria of this systematic review, 5,517 patients and 6,303 vertebral levels were fused. The overall weighted average patient fusion rate following stand-alone ALIF was 88.2% (range: 16.6%-100%). In the 31 studies with at least 50 subjects, the weighted average fusion rate following stand-alone ALIF was 88.6% (range: 57.5%-99.0%). Use of anterior fixation plate devices yielded a fusion rate of 94.2%. Newer zero-profile interbody implants had a fusion rate of 89.2%. Fusion rates were lower in studies with 50% or more subjects having positive smoking and worker's compensation status, however these results were found to be statistically insignificant (p>.05). Fusion rate for subjects in the eight rhBMP-2 study groups was 94.4% (n=889) compared with 84.8% (n=3,102) in 38 study groups without rhBMP-2 used. CONCLUSIONS: Based on the available data, stand-alone ALIF procedures yield high fusion rates overall. Fusion failure and pseudoarthrosis rates are higher in study populations involving a high percentage of smokers or positive workers compensation status. Allograft utilization does not significantly improve fusion rate when compared with autograft in stand-alone ALIF constructs.

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.

What Factors Influence Reimbursement for 1 to 2 Level Anterior Cervical Discectomy and Fusion Procedures?

STUDY DESIGN: Retrospective review. OBJECTIVE: To determine reimbursement associated with an anterior cervical discectomy and fusion (ACDF) and the demographic factors influencing reimbursement for an ACDF. SUMMARY OF BACKGROUND DATA: ACDF has been shown to be a cost-effective procedure. However, there has been minimal analysis of factors influencing reimbursement for this procedure. METHODS: Clinical and financial data were retrospectively reviewed for 176 patients undergoing an ACDF procedure in 2013 and 2014. Patients were included if they had primary ACDF and excluded if they were treated for a traumatic cervical spine fracture, infection, failed primary procedure, front/back procedure, or total disc replacement procedure. Clinical factors analyzed included number of levels fused, surgical time, length of stay in the hospital, estimated blood loss, implant type, Charleson Comorbidity Index (CCI), and preoperative diagnosis. Payer type and reimbursement associated with physician and hospital fees were collected for each patient. A multiple linear regression model determined the factors influencing reimbursement data using a backward conditional stepwise methodology. Variables were only included in multivariate analysis if there was a significant (P < 0.05) impact on reimbursement within univariate analysis. RESULTS: One hundred and twenty-eight patients met inclusion criteria. The average reimbursement per patient was $24,622 (+/- standard deviation of 14,616). The only significant factors influencing reimbursement was payer type (P < 0.001) and length of hospital stay (P < 0.001). These two independent multivariate determinants of reimbursement only accounted for 18.6% of reimbursement variability. CONCLUSION: There is substantial variability in reimbursement for ACDF procedures. Multivariate analysis indicates that payer type and length of hospital stay significantly influence reimbursement. Our model, however, only explained a small proportion of reimbursement variability indicating that factors outside our analysis may significantly affect hospital reimbursement. LEVEL OF EVIDENCE: 3.

Factors Affecting Utilization of Steroid Injections in the Treatment of Lumbosacral Degenerative Conditions in the United States.

BACKGROUND: Lumbar degenerative conditions are an extremely common set of diagnoses with a large spectrum of treatment options. Epidural steroid injections (ESI) are widely used but have come under increased scrutiny as we move toward a value-based model of health care. We assessed current utilization of epidural steroid injections, changes in utilization over time, and the influence of payer type and geographic region within the United States on their utilization. In addition, we analyzed the relationship between ESIs and surgical rates across states. METHODS: The Medicare 5% national sample administrative database (SAF5) and a large national database from a commercial health care company (HORTHO) were used to catalog clinical data for patients with lumbar degenerative conditions. Specific queries into the rate of ESIs and lumbar surgery were also performed within this group. RESULTS: There were 4 108 121 patients found between 2005 and 2015 in the SAF5 and HORTHO databases carrying a diagnosis related to lumbar degenerative conditions. The overall yearly injection rates for patients with lumbar degenerative conditions ranged from 9.84% to 10.18%. In patients older than 65, the rate of ESI was higher for Medicare as compared with private payer insurance (16.27% versus 14.14%, P < .001). There was a higher rate of ESI for patients who eventually underwent surgery in the Medicare group as compared with the commercial group (55.30% versus 40.40%, P < .001). There was a positive correlation between rates of ESI with the rate of surgery between states. CONCLUSIONS: There is considerable variation in treatment of lumbar degenerative conditions with ESI based on payer type. There was increased utilization of lumbar ESI between 2007 and 2012, although this change was less than 0.5%. The data also suggest a positive correlation between rates of ESIs and surgical intervention across states. This points to areas in the country with high utilization of both ESI and surgery in the treatment of lumbar degenerative conditions. LEVEL OF EVIDENCE: III, economic and decision analysis.

Clinical Outcomes of Single-Level Anterior Cervical Discectomy and Fusion.

BACKGROUND: The purpose of the present study was to determine the differences in health outcomes between patients with cervical spondylosis who underwent single-level anterior cervical discectomy and fusion (ACDF) and patients with cervical spondylosis who did not undergo an ACDF fusion (non-ACDF). The hypothesis of the study was that patients undergoing single-level fusion have a lower risk of downstream cardiovascular disease and depression. METHODS: The Medicare 5% sample was used to identify patients who received a diagnosis of spondylosis during 2005-2012. All spondylosis patients were separated into nonoperative and operative groups. Differences in new disease diagnoses, age, sex, and Charlson Comorbidity Index (CCI) scores were recorded. RESULTS: The relative risk (RR) of heart failure was lower in the ACDF group after 3 years (RR = 0.6719; P < .05), 5 years (RR = 0.8477; P = 1.17), and 7 years (RR = 0.7709; P = 1.625). The RR of depression was higher in the ACDF group at 1 year (RR = 2.5008), 3 years (RR = 1.4473), 5 years (RR = 2.2625), and 7 years (RR = 2.2257; P < .05 for all). Mean CCI score of patients before undergoing ACDF was 10 (SD, 9.20), whereas the mean score after surgery was 8 (SD, 7.84; P < .05), and the score for non-ACDF patients remained unchanged at a CCI of 10 (SD, 9.00; P < .05). CONCLUSIONS: The results demonstrate the patients in the ACDF cohort have an increased RR of depression but a decreased risk of cardiovascular disease. Further research may be needed to delineate why the ACDF procedure potentially benefits a patient for heart disease but may stress a patient's social/economic supports during the recovery process, thus leading to higher depression rates for patients undergoing ACDF.

The Use of Magnetic Resonance Imaging and Plain Radiographs Among Adolescents With Back Pain and Adolescent Idiopathic Scoliosis.

BACKGROUND: Low back pain (LBP) and adolescent idiopathic scoliosis (AIS) are common pediatric diagnoses. The workup for these diagnoses can be highly variable and can use significant health care resources. There has been no analysis to date on the use of imaging for workup of AIS and/or LBP. METHODS: The Humana Private Payer Database was queried for clinical and financial information for patients with AIS and/or LBP using International Classification of Diseases (ICD-9) for LBP and AIS. Current procedural terminology codes related to magnetic resonance imaging (MRI) and radiographs for the thoracolumbar spine were used to identify patients with LBP and/or AIS that used these diagnostic imaging modalities. Only patients ages 10 to 19 years were included in this analysis. RESULTS: The total number of patients with AIS and LBP was 18 696 and 56 560, respectively. Thoracolumbar imaging was used within the workup for 71.76% and 45.53% of patients with AIS alone and LBP alone, respectively. MRI was used for 2.92% and 9.53% of patients with AIS alone and LBP alone, respectively. Radiographic imaging was used for 71.06% and 42.63% for AIS alone and LBP alone, respectively. There was minimal variation among regions in use of MRI for AIS. For patients with LBP, the diagnosis with the highest use of MRI was "sciatica" (29.07%). Patients with both LBP and AIS had statistically higher rates of imaging (91.04%), MRI (18.99%), and radiographs (89.71%). Among patients with an MRI, 20.87% never had a radiograph. Reimbursement per patient for radiographs was $164 and $239 for AIS and LBP, respectively. Reimbursement per patient for MRI was $1,263 and $1,882 for AIS and LBP, respectively. CONCLUSIONS: There is substantial use of both MRI and radiographs for adolescents with LBP and/or AIS. Clinicians should be aware of the impact these diagnostic tests have on the patient and the overall health care system.

The Influence of Geography, Time, and Payer Type on the Utilization of Bone Morphogenetic Protein (BMP) Between 2005 and 2015.

Bone morphogenetic protein (BMP) is a critical compound for endochondral bone formation and is used as a bone graft substitute to promote spinal fusion and fracture healing. We sought to identify rate, type, and applications of use of BMP in spinal fusion surgery during 2005 to 2015. The Medicare 5% national sample (SAF5) database and the Humana Orthopaedics database (HORTHO) were searched for patients who underwent spinal fusion with BMP. Rate of use over time and influence of geographic region and payer type on utilization of BMP during 2005 to 2015 were analyzed. A total of 9879 and 12,598 patients were treated with BMP within the SAF5 database and HORTHO databases, respectively. There was a statistically significant variation in use of BMP among geographic regions. Rate of BMP usage for patients above 65 years old was 11.02 and 58.91 patients per 100,000 members for SAF5 and HORTHO databases, respectively (P<0.001). Rate of use of BMP did not vary significantly during 2005 to 2012 within the SAF5 database (P=0.153). There was a trend toward lower use of BMP in the HORTHO database between 2007 and 2015 (P=0.081). BMP use was higher for private pay than Medicare.

A 90-day Bundled Payment for Primary Single-level Lumbar Discectomy/Decompression: What Does "Big Data" Say?

Episode-based bundling may become the major form of reimbursement for many elective spine procedures. As the amount for a 90-day episode of care is not known for a lumbar discectomy, we analyzed the previous reimbursements from Commercial payers (2007-Q2 2015), Medicare Advantage (2007-Q2 2015), and Medicare (2005-2012) for a primary single-level lumbar discectomy/decompression. Distribution of payments among various service providers was studied and a 90-day bundle was simulated. Depending on the payer type, the average facility costs constituted 59.7% to 73.6% of total payments, followed by surgeon's fees, which accounted for 13.7% to 18.5%. Postacute services made up 8.8% to 15.8% of the total reimbursement. Surgeries performed in the inpatient setting were significantly more expensive as compared with surgeries performed in the outpatient setting (P<0.01). The average 90-day bundle amount was estimated at $11,091, $6571, and $6239 for Commercial payers, Medicare Advantage, and Medicare, respectively. Overall, service providers in the Southern region were reimbursed the lowest from Commercial payers and Medicare, compared with other regions. Postacute services are not as major cost drivers after discectomy as after total joint arthroplasty or hip fracture repair.

Bundled payment reimbursement for anterior and posterior approaches for cervical spondylotic myelopathy: an analysis of private payer and Medicare databases.

OBJECTIVE Cervical spondylotic myelopathy (CSM) is a progressive spinal condition that often requires surgery. Studies have shown the clinical equivalency of anterior versus posterior approaches for CSM surgery. The purpose of this study was to determine the amount and type of resources used for anterior and posterior surgical treatment of CSM by using large national databases of clinical and financial information from patients. METHODS This study consists of 2 large cohorts of patients who underwent either an anterior or posterior approach for treatment of CSM. These patients were selected from the Medicare 5% National Sample Administrative Database (SAF5) and the Humana orthopedic database (HORTHO), which is a database of patients with private payer health insurance. The outcome measures were the cost of a 90-day episode of care, as well as a breakdown of the cost components for each surgical procedure between 2005 and 2014. RESULTS A total of 16,444 patients were included in this analysis. In HORTHO, there were 10,332 and 1556 patients treated with an anterior or posterior approach for CSM, respectively. In SAF5, there were 3851 and 705 patients who were treated by an anterior or posterior approach for CSM, respectively. The mean ± SD reimbursements for anterior and posterior approaches in the HORTHO database were $20,863 ± $2014 and $23,813 ± $4258, respectively (p = 0.048). The mean ± SD reimbursements for anterior and posterior approaches in the SAF5 database were $18,219 ± $1053 and $25,598 ± $1686, respectively (p < 0.0001). There were also significantly higher reimbursements for a rehabilitation/skilled nursing facility and hospital/inpatient care for patients who underwent a posterior approach in both the private payer and Medicare databases. In all cohorts in this study, the hospital-related reimbursement was more than double the surgeon-related reimbursement. CONCLUSIONS This study provides resource utilization information for a 90-day episode of care for both anterior and posterior approaches for CSM surgery. There is a statistically significant higher resource utilization for patients undergoing the posterior approach for CSM, which is consistent with the literature. Understanding the reimbursement patterns for anterior versus posterior approaches for CSM will help providers design a bundled payment for patients requiring surgery for CSM, and this study suggests that a subset of patients who require the posterior approach for treatment also require greater resources. The data also suggest that hospital-related reimbursement is the major driver of payments.

What is the Rate of Revision Discectomies After Primary Discectomy on a National Scale?

BACKGROUND: Lumbar discectomy has been shown to be clinically beneficial in numerous studies for appropriately selected patients. Some patients, however, undergo revision discectomy, with previously reported estimates of revisions ranging from 5.1% to 7.9%. No study to date has been able to precisely quantify the rate of revision surgery over numerous years on a national scale. QUESTIONS/PURPOSE: We performed a survival analysis for lumbar discectomy on a national scale using a life-table analysis to answer the following questions: (1) What is the rate of revision discectomy on a national scale over 5 to 7 years for patients undergoing primary discectomy alone? (2) Are there differences in revision discectomy rates based on age of patient, region of the country, or the payer type? METHODS: The Medicare 5% National Sample Administrative Database (SAF5) and a large national database from Humana Inc (HORTHO) were used to catalog the number of patients undergoing a lumbar discectomy. Both of these databases have been cited in numerous peer-reviewed publications during the previous 5 years and routinely are audited by PearlDiver Inc. We identified patients using relevant ICD-9 codes and Current Procedural Terminology (CPT) codes, including ICD-9 72210 (lumbar disc displacement) for disc herniation. We used appropriate CPT codes to identify patients who had a lumbar discectomy. We analyzed patients undergoing additional surgery including those who had repeat discectomy (CPT-63042: laminotomy, reexploration single interspace, lumbar) and patients who had additional more-extensive decompressive procedures with or without fusion after their primary procedure. Revision surgery rates were calculated for patients 65 years and older and those younger than 65 years and for each database (Humana Inc and Medicare). Patients from the two databases also were analyzed based on four distinct geographic regions in the United States where their surgery occurred. There were a total of 7520 patients who underwent a lumbar discectomy for an intervertebral disc displacement with at least 5 years of followup in the HORTHO and SAF5 databases. We used cumulative incidence of revision surgery to estimate the survivorship of these patients. RESULTS: In the HORTHO (2613 patients) and SAF5 (4907 patients) databases, 147 patients (5.6%; 95% CI, 1.8%-9.2%) and 305 patients (6.2%; 95% CI, 3.5%-8.9%) had revision surgery at 7 years after the index discectomy respectively. Survival analysis showed survival rates greater than 93% (95% CI, 91%-98%) for all of the cohorts for a primary discectomy up to 7 years after the surgery. The survivorship was lower for patients younger than 65 years (93% [95% CI, 87%-99%, 1016 of 1091] versus 95% [95% CI, 90%-100%, 1450 of 1522], p = 0.02). When nondiscectomy lumbar surgeries were included, the survivorship of patients younger than 65 years remained lower (83% [95% CI, 76%-89%, 902 of 1091] versus 87% [95% CI, 82%-92%, 1324 of 1522], p = 0.02). There was no difference in revision discectomy rates across geographic regions (p = 0.41) at 7 years. Similarly, there was no difference in additional nondiscectomy lumbar surgery rates (p = 0.68) across geographic regions at 7 years. There was no difference in survivorship rates between patients covered by Medicare (94% [95% CI, 91%-97%], 4602 of 4907) versus Humana Inc (94% [95% CI, 90%-98%], 2466 of 2613) (p = 0.31). CONCLUSIONS: Our study shows rates of cumulative survival after an index lumbar discectomy with revision discectomy as the endpoint. We hope these data allow physicians to offer accurate advice to patients regarding the risk of revision surgery for patients of all ages during 5 to 7 years after their index procedure to enhance shared decision making in spinal surgery. These data also will help public policymakers and accountable care organizations accurately allocate scarce resources to patients with symptomatic lumbar disc herniation. LEVEL OF EVIDENCE: Level III, therapeutic study.

The Top 50 Articles on Minimally Invasive Spine Surgery.

STUDY DESIGN: Bibliometric study of current literature. OBJECTIVE: To catalog the most important minimally invasive spine (MIS) surgery articles using the amount of citations as a marker of relevance. SUMMARY OF BACKGROUND DATA: MIS surgery is a relatively new tool used by spinal surgeons. There is a dynamic and evolving field of research related to MIS techniques, clinical outcomes, and basic science research. To date, there is no comprehensive review of the most cited articles related to MIS surgery. METHODS: A systematic search was performed over three widely used literature databases: Web of Science, Scopus, and Google Scholar. There were four searches performed using the terms "minimally invasive spine surgery," "endoscopic spine surgery," "percutaneous spinal surgery," and "lateral interbody surgery." The amount of citations included was averaged amongst the three databases to rank each article. The query of the three databases was performed in November 2015. RESULTS: Fifty articles were selected based upon the amount of citations each averaged amongst the three databases. The most cited article was titled "Extreme Lateral Interbody Fusion (XLIF): a novel surgical technique for anterior lumbar interbody fusion" by Ozgur et al and was credited with 447, 239, and 279 citations in Google Scholar, Web of Science, and Scopus, respectively. Citations ranged from 27 to 239 for Web of Science, 60 to 279 for Scopus, and 104 to 462 for Google Scholar. There was a large variety of articles written spanning over 14 different topics with the majority dealing with clinical outcomes related to MIS surgery. CONCLUSION: The majority of the most cited articles were level III and level IV studies. This is likely due to the relatively recent nature of technological advances in the field. Furthermore level I and level II studies are required in MIS surgery in the years ahead. LEVEL OF EVIDENCE: 5.

Predictors of discharge to an inpatient rehabilitation facility after a single-level posterior spinal fusion procedure.

PURPOSE: To determine perioperative characteristics of patients undergoing single-level spinal fusion surgery that could help predict discharge to an inpatient rehabilitation facility (IRF). METHODS: Demographic, peri- and postoperative characteristics were reviewed for 107 patients who underwent single-level spinal fusion surgery at a high-volume level I trauma center between January 2011 and December 2013. The relationships between discharge to IRF and gender, age, body mass index (BMI), Charlson Comorbidity Index (CCI), insurance provider, length of stay (LOS), intra- and postoperative outcomes and readmission rates in patients undergoing single-level spinal fusion surgery were analyzed using unpaired and paired t testing. RESULTS: 21.5 % (n = 23) of patients were discharged to an IRF. By using unpaired and paired t tests, it was determined that age, BMI, CCI, LOS and insurance provider were all correlated with a higher probability of being discharged to an IRF. Additionally, a logistic regression model demonstrated a correlation between lower CCI and discharge to an IRF. CONCLUSIONS: Statistically significant differences were seen regarding age, BMI, CCI, LOS and insurance provider when determining the necessity of a patient being discharged to an IRF. These characteristics can be used to begin the process of setting up discharge disposition preoperatively rather than postoperatively. There were no perioperative characteristics that were statistically significant in determining discharge disposition; therefore, physicians can utilize these preoperative demographics in deciding and organizing discharge before the day of surgery, which can diminish LOS and lead to substantial health system savings.

Experimental Design and Surgical Approach to Create a Spinal Fusion Model in a New Zealand White Rabbit (Oryctolagus cuniculus).

There are several animal models routinely used for study of the spinal fusion process and animal selection largely depends on the scientific question to be answered. This review outlines the advantages and disadvantages of various animal models used to study spinal fusion and describes the New Zealand White (NSW) rabbit which is the most popular preclinical model to study spinal fusion. We outline critical steps required in planning and performing spinal fusion surgery in this model. This includes determination of the required animal number to obtain statistical significance, an outline of appropriate technique for posterolateral fusion and other components of completing a study. As advances in drug delivery move forward and our understanding of the cascade of gene expression occurring during the fusion process grows, performing and interpreting preclinical animal models will be vital to validating new therapies to enhance spinal fusion.

Reimbursement Related to a 90-Day Episode of Care for a One or Two-Level Anterior Cervical Discectomy and Fusion.

BACKGROUND: A bundled payment represents a single payment for services during an episode of care for a surgical procedure. Anterior cervical discectomy and fusion (ACDF) and associated 90-day costs have been suggested as a bundle amenable to such a payment structure; however, to our knowledge, there are limited available data with regard to costs related to this procedure and subsequent care. METHODS: The Medicare 5% National Sample Administrative Database was used to catalog clinical and financial data associated with the day of the surgical procedure and the 90-day postoperative period for patients undergoing a one to two-level ACDF procedure from 2005 to 2012. We simultaneously queried the database for total knee replacement as a means to compare the payments and to verify the reliability of our analysis. RESULTS: A total of 4,506 patients underwent an ACDF procedure for cervical radiculopathy. The total 90-day reimbursement was $69,469,550 or a mean cost per patient (and standard deviation) of $15,417 ± $947 (median, $15,589). As a comparison, the mean reimbursement for patients who had undergone a total knee replacement amounted to $17,451 per patient. The physician reimbursement for ACDF represented 20.42% of the total, with the surgeon receiving 18.07% of the total reimbursement. Revision surgery, readmission, and emergency department reimbursement accounted for 0.71% of the total reimbursement. Reimbursement for rehabilitation services, including physical therapy, skilled nursing facilities, and home care, represented 3.11% of the total reimbursement. There was a significant variation in reimbursement among geographic regions in the United States (p < 0.001), with the highest in the West. CONCLUSIONS: To our knowledge, this study is the first report on 90-day reimbursement per patient for one to two-level ACDF procedures in a Medicare cohort. Payments varied significantly among geographic locations. Our study provides a reimbursement benchmark for one to two-level ACDF procedures. Clarifying the payments relative to costs will help providers to understand whether a bundled payment for the ACDF procedure is economically viable.