Percutaneous image-guided cryoablation of spinal metastases: A systematic review.

Percutaneous cryoablation (PCA) is a minimally invasive technique that has been recently used to treat spinal metastases with a paucity of data currently available in the literature. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Prospective or retrospective studies concerning metastatic spinal neoplasms treated with current generation PCA systems and with available data on safety and clinical outcomes were included. In the 8 included studies (7 retrospective, 1 prospective), a total of 148 patients (females = 63%) underwent spinal PCA. Tumors were located in the cervical (3/109 [2.8%], thoracic (74/109 [68.8%], lumbar (37/109 [33.9%], and sacrococcygeal (17/109 [15.6%] regions. Overall, 187 metastatic spinal lesions were treated. Thermo-protective measures (e.g., carbo-/hydro-dissection, thermocouples) were used in 115/187 [61.5%] procedures. For metastatic spinal tumors, the pooled mean difference (MD) in pain scores from baseline on the 0-10 numeric rating scale was 5.03 (95% confidence interval [CI]: 4.24 to 5.82) at a 1-month follow-up and 4.61 (95% CI: 3.27 to 5.95) at the last reported follow-up (range 24-40 weeks in 3/4 studies). Local tumor control rates ranged widely from 60% to 100% at varying follow-ups. Grade I-II complications were reported in 9/148 [6.1%] patients and grade III-V complications were reported in 3/148 [2.0%]) patients. PCA, as a stand-alone or adjunct modality, may be a viable therapy in appropriately selected patients with painful spinal metastases who were traditionally managed with open surgery and/or radiation therapy.

Patients Undergoing 3-Level-or-Greater Decompression-Only Surgery for Lumbar Spinal Stenosis Have Similar Outcomes to Those Undergoing Single-Level Surgery at 2 Years.

BACKGROUND: Stability following multilevel decompressive laminectomy without fusion has been debated using in vitro biomechanical and radiographic models. However, there is a lack of information regarding clinical outcomes for these patients. The aim of the present study was to determine the association between clinical outcomes and number of levels decompressed via laminectomy for treatment of lumbar spinal stenosis. METHODS: We performed a retrospective cohort analysis of patients who underwent a primary lumbar laminectomy between 2009 and 2015 by senior orthopedic spine surgeons for lumbar spinal stenosis. Patients were divided into 2 groups based on the number of decompression levels: single level or 3 or more levels. Patient-reported outcomes were obtained in the form of Oswestry Disability Index (ODI) scores, visual analog scale (VAS) scores for the back and leg, 12-Item Short Form Mental and Physical Survey scores, and Veterans Rand 12-Item Health Mental and Physical Survey scores. RESULTS: Overall, 138 consecutive patients were assessed, of which 106 underwent a single-level and 32 underwent a 3-or-more-level laminectomy. Average follow-up was 24.2 months. There were no significant differences in the preoperative VAS back, VAS leg, or ODI scores between the single-level laminectomy and 3-or-more-level laminectomy groups. Both groups of patients experienced significant improvements in these clinical outcomes postoperatively with no clinically significant difference in the degree of improvement. Reoperation rates were low and similar between the 2 groups. CONCLUSIONS: Patients undergoing decompression of 3 or more levels present with similar postoperative outcomes to those who undergo a single-level decompression for lumbar spinal stenosis. Under specific clinical and radiographic criteria, a multilevel decompression of 3 or more levels may be a safe and effective procedure with acceptable outcomes at 2 years after surgery. LEVEL OF EVIDENCE: 3.

Rigid-Plating and Cortico-Cancellous Allograft Are Effective for 3-Level Anterior Cervical Discectomy and Fusion: Radiographic and Clinical Outcomes.

OBJECTIVE: To determine the risk factors associated with radiographic changes and clinical outcomes following 3-level anterior cervical discectomy and fusion (ACDF) using rigidplate constructs and cortico-cancellous allograft. ACDF has demonstrated efficacy for treatment of multilevel degenerative cervical conditions, but current data exists in small heterogeneous forms. METHODS: A retrospective review included 98 patients with primary 3-level ACDF surgery at one institution from 2008 to 2013 with minimum 1-year follow-up. Cervical sagittal vertical axis (SVA), segmental height, fusion, and lordosis radiographs were measured preoperatively and at 2 postoperative periods. RESULTS: Rates of asymptomatic pseudarthroses and total reoperations were 18% and 4%, respectively. Results demonstrated immediate improvements in cervical lordosis (5.5°, p < 0.01) and segmental height (5.0-mm increase, p < 0.01) with little changes in the cervical SVA (3.2-mm increase, p < 0.01). The segmental height decreased from immediate postoperative period to final follow-up (1.7-mm decrease, p < 0.01). Older age was protective against radiolucent lines (p < 0.05). Patient-reported outcomes significantly improved following surgery (p < 0.01). Current smoking status and diagnosis of diabetes mellitus had no impact on radiographic or clinical outcomes. Risk factors were not identified for the 5 reoperations (4%). CONCLUSION: Three-level ACDF with rigid-plating and cortico-cancellous allograft is an effective procedure for degenerative diseases of the cervical spine without the application of additional adjuncts or combined anteriorposterior cervical surgeries. Significant improvements in cervical lordosis, segmental height, and segmental alignment can be achieved with little change in cervical SVA and a low rate of reoperations over short-term follow-up. Similarly, patient-reported outcomes show significant improvements.

Incidence of Congenital Spinal Abnormalities Among Pediatric Patients and Their Association With Scoliosis and Systemic Anomalies.

BACKGROUND: Congenital abnormalities when present, according to VACTERL theory, occur nonrandomly with other congenital anomalies. This study estimates the prevalence of congenital spinal anomalies, and their concurrence with other systemic anomalies. METHODS: A retrospective cohort analysis on Health care Cost and Utilization Project's Kids Inpatient Database (KID), years 2000, 2003, 2006, 2009 was performed. ICD-9 coding identified congenital anomalies of the spine and other body systems. OUTCOME MEASURES: Overall incidence of congenital spinal abnormalities in pediatric patients, and the concurrence of spinal anomaly diagnoses with other organ system anomalies. Frequencies of congenital spine anomalies were estimated using KID hospital-and-year-adjusted weights. Poisson distribution in contingency tables tabulated concurrence of other congenital anomalies, grouped by body system. RESULTS: Of 12,039,432 patients, rates per 100,000 cases were: 9.1 hemivertebra, 4.3 Klippel-Fiel, 56.3 Chiari malformation, 52.6 tethered cord, 83.4 spina bifida, 1.2 absence of vertebra, and 6.2 diastematomyelia. Diastematomyelia had the highest concurrence of other anomalies: 70.1% of diastematomyelia patients had at least one other congenital anomaly. Next, 63.2% of hemivertebra, and 35.2% of Klippel-Fiel patients had concurrent anomalies. Of the other systems deformities cooccuring, cardiac system had the highest concurrent incidence (6.5% overall). In light of VACTERL's definition of a patient being diagnosed with at least 3 VACTERL anomalies, hemivertebra patients had the highest cooccurrence of ≥3 anomalies (31.3%). With detailed analysis of hemivertebra patients, secundum ASD (14.49%), atresia of large intestine (10.2%), renal agenesis (7.43%) frequently cooccured. CONCLUSIONS: Congenital abnormalities of the spine are associated with serious systemic anomalies that may have delayed presentations. These patients continue to be at a very high, and maybe higher than previously thought, risk for comorbidities that can cause devastating perioperative complications if not detected preoperatively, and full MRI workups should be considered in all patients with spinal abnormalities. LEVEL OF EVIDENCE: Level III.

Comparing Allografts to Autografts for Maintenance of Cervical Sagittal Parameters and Clinical Outcomes Following Anterior Cervical Discectomy and Fusion With Anterior Cervical Plating.

OBJECTIVE: Current literature has not shown if using either allograft or autograft differentially affects postoperative cervical sagittal parameters. The goal of this study was to compare sagittal alignment and patient-reported outcomes following anterior cervical discectomy and fusion (ACDF) with allograft versus autograft. METHODS: A retrospective cohort analysis of patients who underwent single-level ACDF was conducted. Preoperative, immediate postoperative, and final follow-up radiographic assessments were conducted and included: change in C2-7 lordosis, T1 slope, levels fused, sagittal vertical axis (SVA), fusion mass lordosis, and proximal and distal adjacent segment degeneration (ASD). Patient-reported outcomes were obtained using the Neck Disability Index and visual analogue scale scores for neck and arm. RESULTS: A total of 404 patients were assessed; 353 using allograft and 51 using autograft. No significant differences existed in demographics. Cervical lordosis improved in both groups without significant changes in SVA. Autograft group had a significantly greater amount of lordosis at the proximal segment on immediate postoperative radiographs and less overall cervical lordosis at final follow-up. Sagittal parameters were similar at each time point without significant changes between the 3-time points. No significant differences existed in radiographic ASD or reoperation rates. Fusion rates exceeded 96% in both groups. No significant differences existed between preoperative, postoperative, or change in patient-reported outcomes between the 2 groups. CONCLUSION: Sagittal alignment is maintained following ACDF when using either allograft or autograft. Radiographic evidence of ASD is present in both groups; however, this was not considered clinically significant, given low rates of pseudarthrosis or reoperation. No significant differences exist between groups in terms of patient-reported outcomes.

Obesity does not impact clinical outcome but affects cervical sagittal alignment and adjacent segment degeneration in short term follow-up after an anterior cervical decompression and fusion.

BACKGROUND CONTEXT: Obesity increases complications and cost following spine surgery. However, the impact on sagittal alignment and adjacent segment degeneration (ASD) after anterior cervical decompression and fusion is less understood. PURPOSE: To compare clinical and radiographic outcomes after anterior cervical decompression and fusion between obese and nonobese patients. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: In all, 467 patients that underwent an anterior cervical decompression and fusion procedure from January 2008 through December 2015 were assessed. Surgery indications were radiculopathy, myelopathy, or myeloradiculopathy that had failed nonoperative treatments. Exclusion criteria included patients who had postoperative follow-up less than 6 months. Of 467 patients originally identified, 399 fulfilled the inclusion and exclusion criteria. OUTCOME MEASURES: The following patient-reported outcomes were obtained: Neck Disability Index and Visual Analog Scale scores for the neck and arm pain. Radiographic assessments included: C2-C7 lordosis, T1 angle, levels fused, sagittal vertical axis (SVA), fusion mass lordosis, proximal and distal adjacent segment lordosis, ASD, and presence of fusion. METHODS: Plain radiographs were performed preoperatively, immediately postoperatively, and final follow-up. Demographic information was collected on all patients. Baseline patient characteristics were compared using chi-squared analysis and independent sample t tests for categorical and continuous data, respectively. For analysis, patients were divided into 4 groups based on obesity stratification as defined by Center for Disease Control: body mass index (BMI) <25 kg/m2 (normal weight), BMI≥25 kg/m2 to <30 kg/m2 (overweight), ≥30 kg/m2 to <35 kg/m2 (Class I obesity), BMI≥35 kg/m2 to <40 kg/m2 (Class II obesity), and BMI≥40 kg/m2 (Class III obesity). Additionally, obese (≥30 kg/m2) and nonobese (<30 kg/m2) patients were compared in a separate analysis. Multivariate analysis was used to compare clinical and radiographic outcomes among all BMI classes, as well as between BMI≥30 kg/m2 versus BMI<30 kg/m2 study groups. Multivariate analyses controlled for differences in baseline patient characteristics and included age, sex, smoking, American Society of Anesthesiologists Physical Status Score, diabetes mellitus, and number of levels. RESULTS: Of the 399 patients assessed, 97 were identified as normal weight, 157 as overweight, 81 with Class I obesity, 45 with Class II obesity, and 19 with Class III obesity. On multivariate analysis, despite having similar SVA measurements on preoperative radiographs, increase in BMI was associated with increase in postoperative SVA (p=0.041) along with significantly larger SVA in immediate postoperative (p=0.004) and final follow-up radiographs (p=0.003) for patients with BMI≥30 kg/m2 versus BMI<30 kg/m2. Furthermore, patients with BMI≥30 kg/m2 had smaller preoperative (p=0.012), immediate postoperative (p=0.017), and final lordosis (p<0.001) in addition to smaller immediate postoperative (p=0.025) and final fusion segment lordosis (p=0.015) and smaller preoperative (p=0.024) and final distal lordosis (p=0.021) compared with patients with BMI<30 kg/m2. Additionally, greater BMI was associated with lower final Visual Analog Scale neck scores (p=0.008). Radiographic early ASD rates were higher in patients BMI≥30 kg/m2 versus BMI<30 kg/m2 (p=0.028). CONCLUSIONS: Overall, obese patients who underwent anterior cervical decompression and fusion had similar patient-reported outcomes compared with nonobese patients but had worse radiographic parameters and higher rates of ASD development compared with nonobese patients. This underscores the importance of patient selection and surgical approach for both patient populations.

The Duration of Symptoms Does Not Impact Clinical Outcomes Following Lumbar Decompression Surgery.

STUDY DESIGN: A retrospective cohort analysis. OBJECTIVE: The aim of this study was to assess whether duration of symptoms (DOS) has an effect on clinical outcomes in patients undergoing lumbar decompression. SUMMARY OF BACKGROUND DATA: The success of surgical interventions for lumbar spinal stenosis varies depending on numerous factors, including DOS. However, existing literature does not provide a clear indication of the outcome of lumbar decompression surgery in regard to DOS secondary to nerve root compression. METHODS: Analysis of patients who underwent primary lumbar laminectomy from 2008 through 2015 by one of two senior orthopedic spine surgeons was conducted. Exclusion criteria were as follows: previous lumbar surgery, patient under 18 years of age at time of surgery, or postoperative follow-up less than 3 months. Patients were divided into groups on the basis of preoperative DOS: less than 1 year and 1 year or greater. Patient-reported outcomes were obtained using Oswestry Disability Index (ODI) scores, Visual Analog Scales (VAS) scores for the back and leg, 12-Item Short Form Mental and Physical Survey (SF-12) scores, and Veterans Rand 12-Item Health Mental and Physical Survey (VR-12) scores. Patients were surveyed about expectations and postoperative satisfaction. RESULTS: Two hundred ten patients were assessed; 108 with DOS of less than 1 year and 102 with DOS of 1 year or more. On multivariate analysis, patients with DOS of 1 year or greater presented with significantly lower SF-12 scores (P = 0.043). No significant differences existed in other outcome survey scores. Reoperation rates were not significantly different (P = 0.904). Both groups reported high levels of satisfaction (odds ratio 0.42, P = 0.483) and that surgery met or exceeded their expectations (odds ratio 1.00, P = 0.308). CONCLUSION: Symptom chronicity did not significantly affect postoperative clinical outcomes, reoperation rates, or patient satisfaction. Nonoperative treatment of lumbar spinal stenosis is often successful but may delay operative intervention. However, results of this study suggest that the delay does not negatively impact surgical outcomes. LEVEL OF EVIDENCE: 3.

Differences in primary and revision deformity surgeries: following 1,063 primary thoracolumbar adult spinal deformity fusions over time.

BACKGROUND: This study aims to describe properties of adult spinal deformity (ASD) revisions relative to primary surgeries and determine clinical variables that can predict revision. ASD is a common pathology that can lead to decreased quality of life, pain, physical limitations, and dissatisfaction with self-image. Durability of interventions for deformity treatment is of paramount concern to surgeons, as revision rates remain high. METHODS: Patients undergoing thoracolumbar fusion, five or more levels, for scoliosis (primary diagnosis ICD-9 737.x) were identified on a state-wide database. Primary and revision (returning for re-fusion procedure) surgeries were compared based on demographic, hospital stay, and clinical characteristics. Differences between primary and revision surgeries, and predictors of primary surgeries requiring revision, utilized binary logistic regression controlling for age, comorbidity burden, and levels fused. RESULTS: A total of 1,063 patients (average 7.4 levels fused, mean age: 47.6 years, 69.0% female) undergoing operative treatment for ASD were identified, of which 123 (average 7.1 levels fused, 11.6%, mean age 61.43, 80.5% female) had surgical revision. Primary surgeries were ~0.3 levels longer (P=0.013), used interbody ~11% more frequently (P=0.020), and used BMP ~12% less frequently (P=0.008). Revisions occurred 176.4 days after the primary on average. The most frequent causes of revisions were: 43.09% implant failure, 24.39% acquired kyphosis, and 14.63% enduring scoliosis. After controlling for age, comorbidities, and levels fused older, more comorbid, female, and white-race patients were more likely to be revised. Upon multivariate regression, after controlling for age and levels fused, overall complications remained non-different (OR: 0.8, 95% CI: 0.6-1.2). However, revision remained an independent predictor for infection (OR: 5.5, 95% CI: 2.8-10.5). CONCLUSIONS: In a statewide database with individual patient follow up of up to 4 years 10% of ASD patients undergoing scoliosis correction required revision. Revision surgeries had higher infection incidence.

Multi- versus single-level anterior cervical discectomy and fusion: comparing sagittal alignment, early adjacent segment degeneration, and clinical outcomes.

PURPOSE: The purpose of this study was to compare the rates of adjacent segment degeneration (ASD), sagittal alignment parameters, and patient-reported outcomes in patients who underwent multi-level versus single-level anterior cervical discectomy and fusion (ACDF). METHODS: A retrospective cohort analysis was performed on consecutive patients who underwent an ACDF. Pre- and post-operative radiographic assessment included ASD, change in C2-C7 lordosis, T1 angle, levels fused, sagittal vertical axis (SVA), fusion mass lordosis, proximal and distal adjacent segment lordosis. Patient-reported outcomes were obtained. RESULTS: Of the 404 that underwent an ACDF with a minimum of 6 months of follow-up (average 28 months), there was no significant difference in the rate of radiographic ASD overall (p = 0.479) or in the proximal or distal adjacent segments on multivariate analysis. Secondarily, the multi-level fusions appear to restore significantly greater amounts of lordosis compared to single-level procedures (p < 0.001) and are able to maintain the corrected cervical lordosis and fusion segment lordosis over time. From the immediate post-operative period to final follow-up, the single-level ACDFs show continuing lordosis improvement (p = 0.005) that is significantly greater than that of the multi-level constructs. There were no significant differences between pre-operative, post-operative, or change in patient-reported outcomes. CONCLUSIONS: Two years following an ACDF, patients who underwent multi-level fusions appear to restore significantly greater amounts of lordosis compared to single-level procedures, while single-level ACDFs show significantly greater amounts of lordosis improvement over time. Multi-level procedures may not be at a significantly greater risk of developing early radiographic evidence of ASD compared to single-level procedure. These slides can be retrieved under Electronic Supplementary Material.

Predictors of adverse discharge disposition in adult spinal deformity and associated costs.

BACKGROUND CONTEXT: With advances in the understanding of adult spinal deformity (ASD), more complex osteotomy and fusion techniques are being implemented with increasing frequency. Patients undergoing ASD corrections infrequently require extended acute care, longer inpatient stays, and are discharged to supervised care. Given the necessity of value-based health care, identification of clinical indicators of adverse discharge disposition in ASD surgeries is paramount. PURPOSE: Using the nationwide and surgeon-created databases, the present study aimed to identify predictors of adverse discharge disposition after ASD surgeries and view the corresponding differences in charges. STUDY DESIGN/SETTING: This is a retrospective analysis of patients on the National Surgical Quality Improvement Program (NSQIP) database and of cost data from Medicare PearlDiver Database. PATIENT SAMPLE: Patients undergoing thoracolumbar surgery for correction of ASD were included in the study. OUTCOME MEASURES: Primary analysis was performed to compare patients discharged to home with patients who either expired or were discharged to locations other than home. Secondary analysis was performed to determine the cost differences across discharge groups. METHODS: Patients on NSQIP undergoing thoracolumbar ASD-corrective surgery with a primary diagnosis of scoliosis (ICD-9 code 737.x) and over the age of 18 were isolated. Predictors (demographic, clinical, and complications) of not-home (NH; rehab or skilled nursing facility) discharge were analyzed using binary logistic regression controlling for levels fused, decompressions, osteotomies, and revisions. Average 30- and 90-day costs of care were reported in home, rehab, and skilled nursing facility discharge groups in patients undergoing 8+ level thoracolumbar fusion. RESULTS: A total of 1,978 patients undergoing lumbar ASD-corrective surgery were included for analysis (average age: 59.3 years, sex: 64% female). Average length of stay was 6.58 days. On multivariate regression analysis, age over 60 years (odds ratio [OR]: 0.28, confidence interval [CI]: 0.22-0.34) and female sex (p=.003) were independent predictors of adverse discharge status. Partially dependent preoperational functional status, defined as reliance on another person to complete some activities of daily living, increased likelihood of adverse discharge disposition (OR: 0.57, CI: 0.35-0.90). Despite controlling for all clinical variables except for the ones specific to each analysis, Smith-Petersen osteotomy (OR: 0.51, CI: 0.40-0.64), interbody device placement (OR: 0.80, CI: 0.64-0.98), and fixation to the iliac (OR: 0.54, CI: 0.41-0.70) increased the likelihood of adverse discharge. Complications most associated with adverse discharge were urinary tract infections (OR: 0.34, CI: 0.21-0.57) and blood transfusions (OR: 0.42, CI: 0.34-0.52). Relative to home discharge, 30-day costs of care were +$21,061 more expensive in rehab discharges, but not different in skilled nursing facility discharges (+$5,791, p=.177). The 90-day costs of care were $23,815 in rehab discharges (p<.001), but again not different from skilled nursing facility discharges (+$6,091, p=.212). CONCLUSIONS: Discharge destination to rehabilitation has a significant impact on the cost of thoracolumbar ASD surgeries. Patient selection can predict patients at higher risk of discharges to rehab or skilled nursing facility.

Importance of the Sagittal Plane in Understanding Adult Spinal Deformities.

The sagittal plane is known to be important in correction of adult spinal deformity. When surgery is indicated, the surgeon is provided with several tools and techniques to restore balance. But proper use of these tools is essential to avoid harmful complications. This article examines these tools with a focus on lumbar lordosis and the lumbopelvic junction. Positioning, releases, osteotomies, and instrumentation are considered with special attention to the alignment measurements they affect.

Psychosocial Factors and Surgical Outcomes in Adult Spinal Deformity: Do Dementia Patients Have More Complications?

STUDY DESIGN: Retrospective analysis of a prospectively collected, national inpatient hospital database. OBJECTIVE: We aimed to investigate comorbid psychiatric disorders in the adult spinal deformity (ASD) population. We hypothesized that a high incidence of comorbid psychiatric disorders in ASD would negatively impact perioperative outcomes. SUMMARY OF BACKGROUND DATA: Patients with adult spinal fusion (ASF) suffer from severe back pain and often depression. Psychiatric comorbidities in the ASD population are not well understood, despite the apparent psychological effects of spinal deformity-related self-image. METHODS: The Nationwide Inpatient Sample databases from 2001 to 2009 were queried for patients ages 18 years or older with in-hospital stays including a spine arthrodesis. Patients were divided into two groups: ASD (diagnosis of scoliosis, excluding neuromuscular and congenital) and all other ASF. Subjects were further stratified by presence of a comorbid psychiatric diagnosis. Differences between each surgical group in psychiatric frequency and complications were calculated using analysis of variance, adjusted for operative complexity. A binary logistic regression analyzed the association between psychiatric diagnoses and likelihood of complications. RESULTS: A total of 3,366,352 ASF and 219,975 ASD patients were identified. The rate of comorbid psychiatric diagnoses in ASD was significantly higher (23.5%) compared to ASF patients (19.4%, P < 0.001). Complication rates were higher for ASD compared to ASF; patients without a psychiatric diagnosis had lower (or comparable) complication rates than psychiatric patients, across all disorder categories. Patients with psychotic disorders and dementia showed more complications than controls; patients with mood, anxiety and alcohol disorders showed fewer. CONCLUSION: Psychiatric comorbidities are more common in the ASD population than in adult fusion patients. ASD and ASF patients with the most common psychiatric disorders (mood, anxiety, and alcohol abuse) are not at increased risk for complications compared to controls. Those patients with psychotic disorders and dementia are at a significant risk for increased complications and surgeons should be aware of these specific risks. LEVEL OF EVIDENCE: 2.

Does Reoperation Risk Vary for Different Types of Pediatric Scoliosis?

STUDY DESIGN: Retrospective cohort study of spine fusion surgery utilizing the New York State Inpatient Database. OBJECTIVE: The objective was to determine whether there were differences in reoperation rates among pediatric scoliosis associated with various etiologies compared with idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: The incidence of postoperative complications and reoperations is known to vary among patients with diverse scoliosis pathologies. As these are heterogeneous conditions and often with rare occurrence, it is difficult to compare them in a single study. We aimed to assess reoperation events after fusion for several etiologies of pediatric scoliosis. METHODS: The 2008 to 2011 New York State Inpatient Database was queried using International Classification of Diseases (ICD-9-CM) codes for patients with in-hospital stays including a spine arthrodesis for scoliosis. All approaches, all fusion lengths, and ages 10 to 21 were included. Patient identifiers and linkage variables were used to identify revisits. The relative risk of reoperation was calculated for several rare conditions associated with scoliosis. RESULTS: Two thousand three hundred fifty-six pediatric scoliosis fusion surgeries were identified in 2008 in the state of New York. The 1- and 4-year reoperation rate for idiopathic scoliosis was 0.9% and 1.6%, respectively. For nonidiopathic scoliosis, the 1- and 4-year rates were 4.2% and 20.4%, respectively. Of the nonidiopathic scoliosis subtypes, congenital scoliosis (4.7% risk at 1 y, 41.6% at 4 y), the neuromuscular disease arthrogryposis (7.3% risk at 1 y, 28.6% at 4 y), and syndrome neurofibromatosis (9.1% at 1 y, 32.3% at 4 y) showed the highest risk for reoperation. Length of stay and hospital charges were higher for reoperations. CONCLUSIONS: Using a large administrative database, we identified neuromuscular, syndromic, and congenital forms of scoliosis that have the highest relative risk for a reoperation within 1 year. At-risk populations should be identified and resources allocated and preventative measures instituted accordingly to prevent these costly events. LEVEL OF EVIDENCE: Level III.

Stability-preserving decompression in degenerative versus congenital spinal stenosis: demographic patterns and patient outcomes.

BACKGROUND CONTEXT: Although lumbar spinal stenosis often presents as a degenerative condition (degenerative stenosis [DS]), some patients present with symptoms from lifelong narrowing of the spinal canal. These patients have congenital stenosis (CS) and present with symptoms of stenosis at a younger age. Patients with CS often have a distinct pathophysiology with fewer degenerative changes but present with multilevel involvement. In the setting of neurologic symptoms, decompression alone while preserving stability has been proposed for both patient populations. PURPOSE: The purpose of this study is to evaluate if the different etiology for narrowing in CS and DS results in a different natural history of pain progression, different locations requiring decompression, and different outcomes following a stability-preserving decompression procedure. STUDY DESIGN/SETTING: This study used a retrospective cohort study patient sample: We retrospectively reviewed consecutive patients of a single surgeon with DS or CS who underwent surgical decompression without fusion between 2008 and 2014. Patients were excluded if they had undergone a previous lumbar surgical procedure (decompression or fusion) or follow-up less than 12 months. OUTCOME MEASURES: Pre- and postoperative clinical outcome scores including visual analogue scale (VAS) and Oswestry Disability Index (ODI) were recorded. Postoperatively, data were collected regarding complications, the presence of new radicular or myelopathic symptoms, and necessity of reoperation in the lumbar spine. METHODS: Demographic information included age, sex, body mass index, smoking status, and Charleston Comorbidity Index (CCI). Preoperative clinical symptoms as well as the presence of lower extremity radiculopathy and claudication were evaluated. Patients were determined to have a diagnosis of CS by the treating surgeon if primary radiographs revealed shortened pedicles and decreased cross-sectional area of the spinal canal as detailed by previous studies. Binary outcomes were compared between congenital and degenerative cohorts using bivariate and multivariate logistic regression. Multivariate regressions controlled for baseline patient and operative characteristics. RESULTS: The average age of the DS cohort was 66.7±10.7 years, whereas for the CS group, it was 47.1±9.2 years. Average follow-up was 27.6 months. The patients with DS had significantly more comorbidities as shown by the CCI score (2.8±1.6 vs. 0.5±0.6); p<.001) and the American Society of Anesthesiologists (ASA) score ≥3 (52.8% vs. 11.1%; p<.001). Patients with CS presented with higher VAS back (8.0 vs. 5.1; p=.008) and leg (7.9 vs. 4.5; p<.001) scores. Patients with DS presented with significantly greater duration of preoperative back pain and leg pain (42.7 vs. 30.5 months; p=.042). Postoperatively, there were no significant differences in VAS back, leg, or ODI scores. However, a trend toward a lower VAS leg score was present in the patients with CS when compared with patients with DS (2.6±3.0 vs. 4.2±3.2; p<.117). Both patient groups experienced similar levels of symptomatic relief and improvement in VAS and ODI scores. There were no significant differences in new-onset radicular symptoms requiring conservative treatment or reoperation. In both groups combined, 81.9% of patients reported resolution of lower extremity symptoms at final follow-up. Overall, 20.6% of patients experienced new lower-extremity radicular symptoms after a period of resolution of symptoms postoperatively. There were significantly more reoperations following surgical decompression in patients with DS (13.9% vs. 2.8%; p=.02). CONCLUSIONS: Patients with CS and patients with DS respond well to decompression alone, without a supplemental fusion, despite differences in pain experience and presentation. The localization of pathology requiring decompression is similar. The patients with DS were more susceptible to require another operation resulting in a fusion, which confirms the theory that initial microinstability can progress in DS, but is likely not part of the disease process in CS. At just over 2 years after decompression, patients with CS may not need to be treated by a fusion in the setting of lower back pain; however, longer-term follow up is necessary to further assess these outcomes.

Resource Utilization in Adolescent Idiopathic Scoliosis Surgery: Is There Opportunity for Standardization?

INTRODUCTION: Recent healthcare reforms have raised the importance of cost and value in the management of disease. Value is a function of benefit and cost. Understanding variability in resources utilized by individual surgeons to achieve similar outcomes may provide an opportunity for cutting costs though greater standardization. The purpose of this study is to evaluate differences in use of implants and hospital resources among surgeons performing adolescent idiopathic scoliosis (AIS) surgery. METHODS: A multicenter prospective AIS operative database was queried. Patients were matched for Lenke curve type and curve magnitude, resulting in 5 surgeons and 35 matched groups (N = 175). Mean patient age was 14.9 years and curve magnitude 50°. Parameters of interest were compared between surgeons via ANOVA and Bonferroni pairwise comparison. RESULTS: There was no significant difference in percentage curve correction or levels fused between surgeons. Significant differences between surgeons were found for percentage posterior approach, operative time, length of stay (LOS), estimated blood loss (EBL), cell saver transfused, rod material, screw density, number of screws, use of antifibrinolytics, and cessation of intravenous analgesics. Despite differences in EBL and cell saver transfused, there were no differences in allogenic blood (blood bank) use. CONCLUSION: Significant variability in resource utilization was noted between surgeons performing AIS operations, although radiographic results were uniform. Standardization of resource utilization and cost containment opportunities include implant usage, rod material, LOS, and transition to oral analgesics, as these factors are the largest contributors to cost in AIS surgery.

Reoperation Rates After Long Posterior Spinal Fusion: Use of Recombinant Bone Morphogenetic Protein in Idiopathic and Non-idiopathic Scoliosis.

INTRODUCTION: Bone morphogenetic protein (BMP) can increase the likelihood of solid arthrodesis in spinal surgery. This would imply fewer reoperations for pseudarthrosis, but small cohort sizes are inadequate to monitor these events. We sought to examine adolescent idiopathic (AIS) and non-idiopathic scoliosis (NIS) for reoperation events with and without the use of BMP using a large statewide database. METHODS: The 2008-2011 New York State Inpatient Database was queried using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Patients age 10 and older with a diagnosis of scoliosis and an index fusion of greater than 2 spinal motion segments were included. Patient identifiers and linkage variables were used to identify revisits. The relative risk of reoperation was calculated. The use of BMP at the initial inpatient stay was used to define the two cohorts for relative risk assessment. RESULTS: A total of 2,658 and 2,431 cases were identified of AIS and NIS, respectively. The use of BMP at the initial visit was performed at a rate of 4.5% for AIS and 21.0% for NIS fusion surgery. For posterior fusion cases longer than eight levels, the reoperation rate for pseudarthrosis was 1.0% in AIS and 18.4% in NIS (p < .001). For NIS fusions greater than eight levels, the rate of reoperation for pseudarthrosis after using BMP at the index surgery was 5% and 22% when BMP was not used, a relative risk of 4.0 (p < .001). For AIS, there was no substantial increase in risk when not using BMP for fusion greater than eight levels (p < .001). CONCLUSION: We found a significant decrease in the risk of reoperation for pseudarthrosis after long fusions when using BMP in the case of NIS. In contrast, use of BMP does not benefit the AIS population.

An Operative Complexity Index Shows Higher Volume Hospitals and Surgeons Perform More Complex Adult Spine Deformity Operations.

BACKGROUND: Though previous studies have shown improved outcomes associated with higher volume surgeons and hospitals, this may not be replicated in ASDS due to case complexity variation. We hypothesized that high-volume surgeons perform more complex surgeries. Therefore, we defined an Operative Complexity Index (OCI), specifically for the National Inpatient Samples (NIS) data, which provides information on in-hospital postoperative complications, to assess rates of adult spine deformity surgery (ASDS) cases as they relate to surgeon and hospital operative volume. METHODS: The 2001 to 2010 NIS was queried for patients greater than 21 years of age with in-hospital stays, including a spine arthrodesis for a diagnosis of scoliosis. Surgeon and hospital identifiers were used to allocate records into volume quartiles by number of surgeries per year. The OCI was devised considering the number of fusion levels, surgical approach, revision status, and use of osteotomy. The index was validated using blood-loss-related diagnostic and procedural codes. One-way ANOVA assessed continuous measures. Chi-square assessed categorical measures. RESULTS: 141,357 ASDS cases met the inclusion criteria. High-volume surgeons performed a higher rate of longfusions (> 8 levels), revision surgeries, and surgeries requiring osteotomy. The OCI showed weak, but significant, correlation with blood loss values: acute blood loss anemia (r = 0.21) and treatment with blood products (r = 0.12) (p < 0.001). High OCI also was also associated with increased length of stay (r = 0.27) and total charges (r = 0.41) (p < 0.001). CONCLUSIONS: The operative complexity index (OCI) for ASDS increases with high-volume surgeons and centers, indicating it can be useful to adjust for surgical invasiveness in the NIS database. Operative complexity must be considered when evaluating patient safety and quality indices among hospitals and surgeons.

Use of Recombinant Bone Morphogenetic Protein Is Associated With Reduced Risk of Reoperation After Spine Fusion for Adult Spinal Deformity.

STUDY DESIGN: Retrospective review. OBJECTIVE: This study follows the inpatient-stay administrative data that were collected for a cohort of thousands of patients who had spine fusion surgery in the state of New York. We sought to examine adult spinal deformity (ASD) for reoperation events with and without the use of bone morphogenetic protein-2 (BMP). SUMMARY OF BACKGROUND DATA: Randomized controlled trials have suggested that BMP may increase the likelihood of solid arthrodesis in spinal surgery. This would imply fewer reoperations for pseudarthrosis, but small cohort sizes are inadequate to monitor these events. METHODS: The 2008-2011 New York State Inpatient Database was queried using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patients age 21 years and older with a diagnosis of scoliosis and an index fusion of greater than 2 spinal motion segments were included. Patient identifiers and linkage variables were used to identify revisits. The relative risk of reoperation was calculated. The use of BMP at the initial inpatient stay was used to define the 2 cohorts for relative risk assessment. RESULTS: A total of 3751 patients of ASD were identified in 2008. The use of BMP at the initial visit was performed at a rate of 37.6% for ASD. For posterior fusion cases longer than 8 levels, the rate of reoperation for a pseudarthrosis was 23.4%. For ASD fusions greater than 8 levels, the rate of reoperation for pseudarthrosis after using BMP at the index surgery was 5% and 33.9% when BMP was not used, a relative risk of 7.5 (P < 0.001). CONCLUSION: Using relevant inhospital patient records from the New York State Inpatient Sample, we found a 7.5-fold decrease in the risk of reoperation for pseudarthrosis after long fusions when using BMP. Decreased reoperation rates are caused by the improved fusion with the use of BMP. If subsequent unnecessary hospitals stays can be avoided, the economics of BMP use should be reexamined.

Complication rates are reduced for revision adult spine deformity surgery among high-volume hospitals and surgeons.

BACKGROUND CONTEXT: Revision adult spinal deformity surgery (RASDS) is a particularly high-risk intervention. PURPOSE: The aim was to assess complication rates in RASDS by surgeon and hospital operative volume. STUDY DESIGN/SETTING: This was a retrospective analysis of prospectively collected data. PATIENT SAMPLE: Based on a Nationwide Inpatient Sample (NIS) database (2001-2010), patients aged older than 21 years (International Classification of Diseases, Ninth Revision, Clinical Modification) with spine arthrodesis for scoliosis were included. For longitudinal analysis, the 2008-2011 New York State Inpatient Database (NY SID) was queried. OUTCOME MEASURES: The outcome measures included complication rate after RASDS. METHODS: Cases were identified as primary or revision surgery with or without osteotomy performed. Annual surgeon and hospital volumes were stratified into quartiles via identifier codes. Case complexity was determined using a novel operative complexity index, based on available NIS operative parameters: levels fused, approach, osteotomy, and revision status. The primary end point was morbidity during the hospital stay. New York State Inpatient Database analysis allowed for identification of rate of reoperation for infection or pseudarthrosis/implant failure. One-way analysis of variance was used to assess continuous measures, chi-square for categorical measures. RESULTS: Of 139,150 adult spinal deformity surgery (ASDS) cases, 4,888 revision with hospital identifiers and 1,978 with surgeon identifiers were identified. Higher-volume surgeons performed more revision cases and cases requiring osteotomy. With increasing hospital volume, complication rate for RASDS decreased (9.7% vs. 12.9% at highest- vs. lowest-volume centers, p< .001). The highest-volume surgeons showed significant decreases in the rate of major complications for RASDS (8.8% vs. 10.7% for lowest-volume surgeons, p< .001). A similar trend was observed for ASDS cases requiring osteotomy. Multiple logistic regression analysis showed that the highest-volume hospitals and surgeons showed a reduced odds ratio for all complications compared with lowest-volume hospitals. For the NY SID, 528 RASDS cases indicated reoperation rates for infection and pseudarthrosis/implant failure after RASDS were increased for the lowest-volume hospitals and surgeons. CONCLUSIONS: Perioperative complication rate associated with RASDS is lower when patients are treated by high-volume surgeons at high-volume centers. As complex cases requiring osteotomy and combined approaches are more frequent at high-volume centers, an operative complexity index helps predict the likelihood of volume-dependent complication rates. Future interhospital and intersurgeon comparisons should account for these case characteristics so that similar case complexity is compared in these analyses.

High-Volume Hospitals and Surgeons Experience Fewer Early Reoperation Events After Adolescent Idiopathic Scoliosis Surgery.

STUDY DESIGN: Retrospective analysis of relevant in-hospital patient records from the New York State Inpatient Database. OBJECTIVE: We aimed to assess reoperation risk in adolescent idiopathic scoliosis (AIS) by surgeon and hospital operative volume. SUMMARY OF BACKGROUND DATA: The need for early reoperation can be devastating for patient and family, is a burden to the physician and adds significant cost. Previous studies have shown improved outcomes associated with higher volume surgeons and hospitals, but reoperation events have not yet been explored. METHODS: The 2008-2011 New York State Inpatient Database was queried using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for adolescent idiopathic scoliosis patients aged 10-21 undergoing spine arthrodesis. Patient identifiers and revisit linkage variables were used to identify reoperation events. Annual surgeon and hospital volumes were stratified into tertiles (low, medium, high) via identifier codes. The relative risk of reoperation after spine arthrodesis was computed based on relevant patient inpatient stays. RESULTS: Over 2008 to 2011, a total of 3,928 primary fusion operations for AIS were identified. The overall rate of reoperation after spine fusion for idiopathic scoliosis was 7.1%. Low volume surgeons performed less than 6 AIS fusions per year, medium volume surgeons performed less than 43, and high volume surgeons performed from 43 to 228. Reoperation after a primary fusion for adolescent idiopathic scoliosis showed reduced frequency among higher volume surgeons (14.1% for low vs. 5.1% for high, p<0.001, see Table for Hospitals). CONCLUSIONS: Early reoperation after spine fusion for idiopathic scoliosis is seen more frequently in lower volume institutions and surgeons. Appreciating the resources and limitations at a clinician's institution is important to developing practices to prevent these devastating events. This work also has implications for strategies that aim to direct limited healthcare resources to centers with low complication rates.