Development and internal validation of predictive models to assess risk of post-acute care facility discharge in adults undergoing multi-level instrumented fusions for lumbar degenerative pathology and spinal deformity.

PURPOSE: To develop a model for factors predictive of Post-Acute Care Facility (PACF) discharge in adult patients undergoing elective multi-level (≥ 3 segments) lumbar/thoracolumbar spinal instrumented fusions. METHODS: The State Inpatient Databases acquired from the Healthcare Cost and Utilization Project from 2005 to 2013 were queried for adult patients who underwent elective multi-level thoracolumbar fusions for spinal deformity. Outcome variables were classified as discharge to home or PACF. Predictive variables included demographic, pre-operative, and operative factors. Univariate and multivariate logistic regression analyses informed development of a logistic regression-based predictive model using seven selected variables. Performance metrics included area under the curve (AUC), sensitivity, and specificity. RESULTS: Included for analysis were 8866 patients. The logistic model including significant variables from multivariate analysis yielded an AUC of 0.75. Stepwise logistic regression was used to simplify the model and assess number of variables needed to reach peak AUC, which included seven selected predictors (insurance, interspaces fused, gender, age, surgical region, CCI, and revision surgery) and had an AUC of 0.74. Model cut-off for predictive PACF discharge was 0.41, yielding a sensitivity of 75% and specificity of 59%. CONCLUSIONS: The seven variables associated significantly with PACF discharge (age > 60, female gender, non-private insurance, primary operations, instrumented fusion involving 8+ interspaces, thoracolumbar region, and higher CCI scores) may aid in identification of adults at risk for discharge to a PACF following elective multi-level lumbar/thoracolumbar spinal fusions for spinal deformity. This may in turn inform discharge planning and expectation management.

Failure in Adult Spinal Deformity Surgery: A Comprehensive Review of Current Rates, Mechanisms, and Prevention Strategies.

STUDY DESIGN: Literature review. OBJECTIVE: The aim of this review is to summarize recent literature on adult spinal deformity (ASD) treatment failure as well as prevention strategies for these failure modes. SUMMARY OF BACKGROUND DATA: There is substantial evidence that ASD surgery can provide significant clinical benefits to patients. The volume of ASD surgery is increasing, and significantly more complex procedures are being performed, especially in the aging population with multiple comorbidities. Although there is potential for significant improvements in pain and disability with ASD surgery, these procedures continue to be associated with major complications and even outright failure. METHODS: A systematic search of the PubMed database was performed for articles relevant to failure after ASD surgery. Institutional review board approval was not needed. RESULTS: Failure and the potential need for revision surgery generally fall into 1 of 4 well-defined phenotypes: clinical failure, radiographic failure, the need for reoperation, and lack of cost-effectiveness. Revision surgery rates remain relatively high, challenging the overall cost-effectiveness of these procedures. CONCLUSION: By consolidating the key evidence regarding failure, further research and innovation may be stimulated with the goal of significantly improving the safety and cost-effectiveness of ASD surgery.

Economic Impact of Revision Operations for Adjacent Segment Disease of the Subaxial Cervical Spine.

INTRODUCTION: Adjacent segment disease (ASD) of the cervical spine is a common disabling phenomenon that often requires surgical intervention. The goal of this study was to evaluate the economic impact of revision operations for cervical ASD. METHODS: Consecutive adults who underwent revision cervical spine surgery for ASD at a single institution between 2014 and 2017 were retrospectively reviewed. Direct costs were identified from medical billing data and calculated for each revision surgery for ASD. Incomplete cost data for revision operations were used as a criterion for exclusion. Cost data were stratified based on the approach of the index and revision operations. RESULTS: Eighty-five patients (average age 57 ± 10 years) underwent revisions for cervical ASD, which summed to $2 million (average $23,702). Revisions consisted of 45 anterior operations (anterior cervical diskectomy and fusion, 34; corpectomy, 10; and cervical disk arthroplasty, 1), 32 posterior operations (posterior cervical fusion, 14; foraminotomy, 14; and laminoplasty, 4), and 8 circumferential operations. Circumferential revisions had notably higher average direct costs ($57,376) than single approaches (anterior, $20,084 and posterior, $20,371). Of posterior revisions, foraminotomies had the lowest average direct costs ($5,389), whereas posterior cervical fusion had the highest average direct costs ($35,950). Of anterior revisions, corpectomies ($30,265) had notably greater average direct costs than anterior cervical diskectomy and fusion ($17,514). Costs were not notably different for revision approaches based on the index operations' approach. DISCUSSION: Revision operations for cervical ASD are highly heterogeneous and associated with an average direct cost of $27,702. Over 3 years, revisions for 85 patients with cervical ASD represented a notable economic expense (greater than $2.0 million). DATA AVAILABILITY: Deidentified data may be provided by request to the corresponding author.

Implementation of Outpatient Minimally Invasive Lumbar Decompression at an Academic Medical Center without Ambulatory Surgery Centers: A Cost Analysis and Systematic Review.

BACKGROUND: Lumbar decompressions are increasingly performed at ambulatory surgery centers (ASCs). We sought to compare costs of open and minimally invasive (MIS) lumbar decompressions performed at a university without dedicated ASCs. METHODS: Lumbar decompressions performed at a tertiary academic hospital or satellite university hospital dedicated to outpatient surgery were retrospectively reviewed. Care pathways were same-day, overnight observation, or inpatient admission. Patient demographics, American Society of Anesthesiologists classification, Charlson Comorbidity Index, surgical characteristics, 30-day readmission, and costs were collected. A systematic review of lumbar decompression cost literature was performed. RESULTS: A total of 354 patients, mean age 55 years with 128 women (36.2%), were reviewed. There was no significant difference in age, gender, body mass index, American Society of Anesthesiologists classification, or Charlson Comorbidity Index between patients treated with open and minimally invasive surgery. Open decompression was associated with higher total cost ($21,280 vs. $14,407; P < 0.001); however, this was driven by care pathway and length of stay. When stratifying by care pathway, there was no difference in total cost between open versus minimally invasive surgery among same-day ($10,609 vs. $11,074; P = 0.556), overnight observation ($14,097 vs. $13,992; P = 0.918), or inpatient admissions ($24,507 vs. $27,929; P = 0.311). CONCLUSIONS: When accounting for care pathway, the cost of open and MIS decompression were no different. Transition from a tertiary academic hospital to a university hospital specializing in outpatient surgery was not associated with lower costs. Academic departments may consider transitioning lumbar decompressions to a dedicated ASC to maximize cost savings; however, additional studies are needed.

Cost Analysis of Outpatient Anterior Cervical Discectomy and Fusion at an Academic Medical Center without Dedicated Ambulatory Surgery Centers.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) are increasingly performed at ambulatory surgical centers (ASCs). Academic centers lacking dedicated ASCs must perform these at large university hospitals, which pose unique challenges to cost savings and efficiency. OBJECTIVE: To describe the safety and cost of outpatient ACDF at a major academic medical center without a dedicated ASC. METHODS: ACDFs performed from 2015 to 2018 were retrospectively reviewed. Cases were performed at the major tertiary university hospital or a satellite university hospital dedicated to outpatient surgery. Patient demographics, surgical characteristics, perioperative complications, fusion at 12 months, and cost were collected. RESULTS: A total of 470 patients were included. The mean age was 56 years, with 255 women (54.3%). When comparing same-day discharge, overnight observation, or inpatient admission, there were no differences in age, gender, or number of levels fused. Same-day and overnight observation cases were associated with shorter procedure duration and less estimated blood loss. There were no differences in perioperative complications, 30-day readmissions, or fusion at 12 months. Direct and total costs were lowest for same-day cases, followed by overnight observation and inpatient admissions (P < 0.001). CONCLUSION: Academic centers without dedicated ASCs can safely perform ACDF as a same-day or overnight observation procedure with significant reductions in cost. The lack of a dedicated ASC should not preclude academic centers from allocating appropriately selected patients into same-day or overnight observation care pathways. This strategy can improve resource utilization and preserve precious hospital resources for the most critically ill patients while also allowing these centers to build viable outpatient spine practices.

Adult Spinal Deformity Knowledge in Orthopedic Spine Surgeons: Impact of Fellowship Training, Experience, and Practice Characteristics.

STUDY DESIGN: Survey study. OBJECTIVE: The purpose of this paper was to assess the level of adult spine deformity (ASD) knowledge among orthopedic spine surgeons and identify areas for improvement in spine surgery training. SUMMARY OF BACKGROUND DATA: ASD is increasingly encountered in spine surgery practice. While ASD knowledge among neurosurgeons has been evaluated, ASD knowledge among orthopedic spine surgeons has not previously been reported. METHODS: A survey of orthopedic spine surgeon members of North American Spine Society (NASS) was conducted to assess level of spine surgery training, practice experience, and spinal deformity knowledge base. The survey used was previously completed by a group of neurologic surgeons with published results. The survey used 11 questions developed and agreed upon by experienced spinal deformity surgeons. RESULTS: Complete responses were received from 413 orthopedic spine surgeons. The overall correct-answer rate was 69.0%. Surgeons in practice for less than 10 years had a higher correct-answer rate compared to those who have practiced for 10 years or more (74% vs. 67%; p = .000003). Surgeons with 75% or more of their practice dedicated to spine had a higher overall correct rate compared to surgeons whose practice is less than 75% spine (71% vs. 63%; p = .000029). Completion of spine fellowship was associated with a higher overall correct-answer rate compared to respondents who did not complete a spine fellowship (71% vs. 59%; p < .00001). CONCLUSIONS: Completion of spine fellowship and having a dedicated spine surgery practice were significantly associated with improved performance on this ASD knowledge survey. Unlike neurosurgeons, orthopedic spine surgeons who have practiced for less than 10 years performed better than those who have practiced for more than 10 years. Ongoing emphasis on spine deformity education should be emphasized to improve adult spinal deformity knowledge base.

Proximal junctional kyphosis and failure after spinal deformity surgery: a systematic review of the literature as a background to classification development.

STUDY DESIGN: Systematic review of literature. OBJECTIVE: To perform a comprehensive English language systematic literature review of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF), concentrating on incidence, risk factors, health related quality of life impact, prevention strategy, and classification systems. SUMMARY OF BACKGROUND DATA: PJK and PJF are well described clinical pathologies and are a frequent cause of revision surgery. The development of a PJK classification that correlates with clinical outcomes and guides treatment decisions and possible prevention strategies would be of significant benefit to patients and surgeons. METHODS: The phrases "proximal junctional," "proximal junctional kyphosis," and "proximal junctional failure" were used as search terms in PubMed for all years up to 2014 to identify all articles that included at least one of these terms. RESULTS: Fifty-three articles were identified overall. Eighteen articles assessed for risk factors. Eight studies specifically reviewed prevention strategies. There were no randomized prospective studies. There were 3 published studies that have attempted to classify PJK. The reported incidence of PJK ranged widely, from 5% to 46% in patients undergoing spinal instrumentation and fusion for adult spinal deformity. It is reported that 66% of PJK occurs within 3 months and 80% within 18 months after surgery. The reported revision rates due to PJK range from 13% to 55%. Modifiable and nonmodifiable risk factors for PJK have been characterized. CONCLUSION: PJK and PJF affect many patients after long segment instrumentation after the correction of adult spinal deformity. The epidemiology and risk factors for the disease are well defined. A PJK and PJF scoring system may help describe the severity of disease and guide the need for revision surgery. The development and prospective validation of a PJK classification system is important considering the prevalence of the problem and its clinical and economic impact. LEVEL OF EVIDENCE: N/A.

Results of the AANS membership survey of adult spinal deformity knowledge: impact of training, practice experience, and assessment of potential areas for improved education: Clinical article.

OBJECT: Adult spinal deformity (ASD) surgery is increasing in the spinal neurosurgeon's practice. METHODS: A survey of neurosurgeon AANS membership assessed the deformity knowledge base and impact of current training, education, and practice experience to identify opportunities for improved education. Eleven questions developed and agreed upon by experienced spinal deformity surgeons tested ASD knowledge and were subgrouped into 5 categories: (1) radiology/spinopelvic alignment, (2) health-related quality of life, (3) surgical indications, (4) operative technique, and (5) clinical evaluation. Chi-square analysis was used to compare differences based on participant demographic characteristics (years of practice, spinal surgery fellowship training, percentage of practice comprising spinal surgery). RESULTS: Responses were received from 1456 neurosurgeons. Of these respondents, 57% had practiced less than 10 years, 20% had completed a spine fellowship, and 32% devoted more than 75% of their practice to spine. The overall correct answer percentage was 42%. Radiology/spinal pelvic alignment questions had the lowest percentage of correct answers (38%), while clinical evaluation and surgical indications questions had the highest percentage (44%). More than 10 years in practice, completion of a spine fellowship, and more than 75% spine practice were associated with greater overall percentage correct (p < 0.001). More than 10 years in practice was significantly associated with increased percentage of correct answers in 4 of 5 categories. Spine fellowship and more than 75% spine practice were significantly associated with increased percentage correct in all categories. Interestingly, the highest error was seen in risk for postoperative coronal imbalance, with a very low rate of correct responses (15%) and not significantly improved with fellowship (18%, p = 0.08). CONCLUSIONS: The results of this survey suggest that ASD knowledge could be improved in neurosurgery. Knowledge may be augmented with neurosurgical experience, spinal surgery fellowships, and spinal specialization. Neurosurgical education should particularly focus on radiology/spinal pelvic alignment, especially pelvic obliquity and coronal imbalance and operative techniques for ASD.

Socioeconomic factors associated with pituitary apoplexy.

OBJECT: Pituitary apoplexy is associated with worse outcomes than are pituitary adenomas detected without acute clinical deterioration. The association between pituitary apoplexy and socioeconomic factors that may limit access to health care has not been examined in prior studies. METHODS: This study involved retrospectively evaluating data obtained in all patients who underwent surgery for nonfunctioning pituitary adenoma causing visual symptoms between January 2003 and July 2012 at the University of California, San Francisco. Patients were grouped into those who presented with apoplexy and those who did not ("no apoplexy"). The 2 groups were compared with respect to annual household income, employment status, health insurance status, and whether or not the patient had a primary health care provider. Associations between categorical variables were analyzed by chi-square test and continuous variables by Student t-test. Multivariate logistic regression was also performed. RESULTS: One hundred thirty-five patients were identified, 18 of whom presented with apoplexy. There were significantly more unmarried patients and emergency room presentations in the apoplexy group than in the "no apoplexy" group. There was a nonsignificant trend toward lower mean household income in the apoplexy group. Lack of health insurance and lack of a primary health care provider were both highly significantly associated with apoplexy. In a multivariate analysis including marital status, emergency room presentation, income, insurance status, and primary health care provider status as variables, lack of insurance remained associated with apoplexy (OR 11.6; 95% CI 1.9-70.3; p = 0.008). CONCLUSIONS: The data suggest that patients with limited access to health care may be more likely to present with pituitary apoplexy than those with adequate access.

Treatment-related morbidity and the management of pediatric craniopharyngioma: a systematic review.

OBJECT: Craniopharyngiomas are benign tumors but their close anatomical relationship with critical neurological, endocrine, and vascular structures makes gross-total resection (GTR) with minimal morbidity difficult to achieve. Currently, there is controversy regarding the extent, timing, and modality of treatment for pediatric craniopharyngioma. METHODS: The authors performed a systematic review of the published literature on pediatric craniopharyngioma to determine patterns of clinical practice and the reported outcomes of standard treatment strategies. This yielded 109 studies, which contained data describing extent of resection for a total of 531 patients. Differences in outcome were examined based upon extent of resection and choice of radiation treatment. RESULTS: Gross-total resection was associated with increased rates of new endocrine dysfunction (OR 5.4, p < 0.001), panhypopituitarism (OR 7.8, p = 0.006), and new neurological deficits (OR 9.9, p = 0.03) compared with biopsy procedures. Subtotal resection (STR) was not associated with an increased rate of new neurological deficits. Gross-total was associated with increased rates of diabetes insipidus (OR 7.7, p = 0.05) compared with the combination of STR and radiotherapy (RT). The addition of RT to STR was associated with increased rates of panhypopituitarism (OR 9.9, p = 0.01) but otherwise similar rates of morbidities. CONCLUSIONS: Although subject to the limitations of a literature review, this report suggests that GTR is associated with increased rates of endocrinopathies compared with STR + RT, and this should be considered when planning goals of surgery.