Faculty Bibliography

BACKGROUND CONTEXT: Chiari malformations (CM) are congenital or acquired hind brain anomalies with resultant cerebellar tonsillar herniation through the foramen magnum. Chiari I malformation consists of herniation of the cerebellar tonsils into the foramen magnum thus crowding the craniocervcial junction. Surgical management is variable among these type 1 patients(pts) based on their presenting symptoms. PURPOSE: Identify complication rates following CM surgery. STUDY DESIGN/SETTING: Retrospective cohort study of (Kids' Inpatient Database) KID. PATIENT SAMPLE: Chiari Malformation Type I. OUTCOME MEASURES: Complication rates, fusion, decompression, duroplasty, laminectomy, LOS, Readmission.
METHOD(S): The KID database was queried for diagnoses of operative Chiari Malformation from 2003-2012 by ICD-9 codes (348.4). Differences in preoperative demographics (age/BMI) and perioperative complication rates between patient cohorts were assessed using Pearson's chi-squared tests and T-tests when necessary. Binary logistic regression were utilized to find significant factors associated with complication rate. Decision tree analysis was utilized for continuous variables predictive of complication rate. Certain surgical procedures were analyzed for their relationship with post-operative outcomes.
RESULT(S): A total of 13,812 CM-1 patients were isolated (10.12 yrs, 0.62 CCI). Of these pts, 8.2% (1,128) received a complication. From 2003 to 2012, the rate of complications for CM-1 pts decreased significantly (9.6%-5.1%) along with surgical rate (33.3%-28.6%), despite the increase in CM diagnosis (36.3%-42.3%; all p<0.05). CM-1 pts who had a complication were younger (9.73+/-6.8 yrs vs 10.2+/-6.3 yrs) and had a lower invasiveness score (0.35+/-1.0 vs 0.41+/-1.0), however; they had a larger CCI (1.10+/-1.6 vs 0.6+/-1.3) than those who did not have a complication (all p<0.05). The most prevalent comorbidities for these pts were cerebrovascular (16.67%), malignancy (11.6%), pulmonary (9.6%), and renal (7.1%; all p<0.05). CM-1 pts who experienced complications had a concurrent diagnosis of syringomyelia (7.1%) and also Scoliosis (3.2%; all p<0.05). CM-1 pts who did not have a complication had a greater surgical rate than those that had a complication (76.4% vs 23.6% p<0.05). Having an interbody instrument, having an invasiveness score>4.25 and receiving a fusion greater than 4 levels were all significant factors associated with receiving a complication postoperatively (p<0.05). The most common complication was nervous system related (2.8%), anemia (2.4%), and acute respiratory distress (2.1%). CM-1 pts that underwent a fusion (3.4% vs 2.1%) had greater complication rates as well as those that underwent a craniotomy (23.2% vs 19.1%; all p<0.05). However, CM-1 pts who underwent a decompression had lower postop complications (21.3% vs 28.9%; all p<0.05). A total of 13,812 CM-1 patients isolated (10.12 yrs, 0.62 CCI). Of these pts, 8.2% (1,128) received a complication. From 2003 to 2012, the rate of complications for CM-1 pts decreased significantly (9.6%-5.1%) along with surgical rate (33.3%-28.6%), despite the increase in CM diagnosis (36.3%-42.3%; all p<0.05). CM-1 pts who had a complication were younger (9.73+/-6.8yrs vs 10.2+/-6.3yrs) and had a lower invasiveness score (0.35+/-1.0 vs 0.41+/-1.0), however; they had a larger CCI (1.10+/-1.6 vs 0.6+/-1.3) than those who did not have a complication (all p<0.05). The most prevalent comorbidities for these pts were cerebrovascular (16.67%), malignancy (11.6%), pulmonary (9.6%), and renal (7.1%; all p<0.05). CM-1 pts who experienced complications had a concurrent diagnosis of syringomyelia (7.1%) and also Scoliosis (3.2%; all p<0.05). CM-1 pts who did not have a complication had a greater surgical rate than those that had a complication (76.4% vs 23.6% p<0.05). Having an interbody instrument, having an invasiveness score>4.25 and receiving a fusion greater than 4 levels were all significant factors associated with receiving a complication postoperatively (p<0.05). The most common complication was nervous system related (2.8%), anemia (2.4%), and acute respiratory distress (2.1%). CM-1 pts that underwent a fusion (3.4% vs 2.1%) had greater complication rates as well as those that underwent a craniotomy (23.2% vs 19.1%; all p<0.05). However, CM-1 pts that underwent a decompression had lower postop complications (21.3% vs 28.9%; all p<0.05).
CONCLUSION(S): Treatment of Chiari malformation has been identified to have improved from 2003 to 2012 with increased identification of diagnosis and decreased complications. Chiari patients undergoing fusions and craniotomies are at a greater risk of postoperative complications especially when the instrumented fusions are performed on >4 levels. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: MBDs are often implicated in or contribute to degenerative disc disease (DDD). Yet, there is limited long-term, postoperative outcome data on the impact of MBDs on 2-year outcomes following 2-3-level lumbar fusion for DDD. PURPOSE: To determine if DDD patients with MBDs have comparable outcomes to those without MBDs following lumbar fusion. STUDY DESIGN/SETTING: Retrospective cohort. PATIENT SAMPLE: New York State Statewide Planning and Research Cooperative System was reviewed from 2009-2013 to identify all patients with DDD who underwent short, lumbar fusion (2-3-levels) with >=2-year follow-up OUTCOME MEASURES: Two-year outcome rates (medical/surgical complications and reoperations).
METHOD(S): The New York State Statewide Planning and Research Cooperative System was reviewed from 2009-2013 to identify all patients with DDD who underwent short, lumbar fusion (2-3 levels) with >=2-year follow-up. Patients with and without MBD (vitamin D deficiency, hyperparathyroidism, osteomalacia, and rickets) were identified. Any patients with osteoporosis or other systemic/endocrine disorders affecting bone quality were excluded. Traumatic, infectious, and neoplastic surgical indications were excluded. Cohorts were compared for demographics and 2-year outcome rates (medical/surgical complications and reoperations). Logistic regression was used to identify covariates associated with medical/surgical complications and revisions.
RESULT(S): A total of 28,959 patients were included (MBD, n=380 (1.33%); no-MBD, n=28,579). MBD pts were older (56.4 vs 53.1 years) and more often female (65.5% vs 49.80%) than no-MBD pts (all p<0.001). MBD pts had longer hospital stays (4.57 days vs 4.11 days, p=0.026), but charges were similar. MBD pts incurred higher rates of wound complications (11.8% vs 6.0%), acute renal failure (11.1% vs 4.7%), pneumonia (9.2% vs 4.4%), and implant related complications (12.1% vs 7.0%); all p<0.001. Rates of pseudarthrosis, PE, pulmonary complications, and UTI were similar between groups. MBDs were associated with developing both medical complications (OR=1.55) and surgical complications (OR=1.79), both p<0.001.
CONCLUSION(S): MBD patients have an increased risk of 2-year postop comps and reoperations following short lumbar fusion for DDD compared to patients without MBD when controlling for demographics and comorbidity profile. These data underscore the importance of preoperative screening and optimization in this patient population. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adult spinal deformity (ASD) corrective surgery is often associated with high rates of adverse outcomes during the recovery course. With the growth of predictive analytics in the medical field, it is important to utilize the developing machine-learning resources to consider the risks associated with major operations. PURPOSE: To assess the validity of the ACS-NSQIP risk index for postop complications and mortality in a prospective multicenter ASD database. STUDY DESIGN/SETTING: Retrospective cohort study of a prospective multicenter ASD database PATIENT SAMPLE: A total of 1,281 ASD patients. OUTCOME MEASURES: Predictive performance of the ACS-NSQIP calculator in an ASD database.
METHOD(S): Patients>18yrs undergoing surgery for ASD (scoliosis>=20degree, SVA>=5cm, PT>=25degree or TK>=60degree). Calculated perioperative complication risk averages via the ACS-NSQIP surgical calculator with CPT codes were compared with 30-day complication rates in the ASD database. Outcomes assessed (as defined by NSQIP): serious complication, any complication, pneumonia, cardiac complication, SSI, UTI, VTE, renal failure, return to OR, death, sepsis and length of hospital stay. Predictive performance of the calculator was analyzed by Brier score (sum of squared differences between the binary outcome and the predicted risk). It ranges from 0 to a maximum Brier score [(mean observed outcome)*(1-[mean observed outcome])]. Values closer to 0 are suggestive of better predictive performance (>0.05 considered poor). Length of stay was assessed with a Bland-Altman plot, observed LOS on the x-axis and the difference between the observed and predicted LOS on the y-axis. Performance of the calculator for serious/any complications for surgeries indicated as 'Risk significantly higher than estimate' was assessed by comparing means of patients who were in the top quartile for their ISSG-invasiveness scores.
RESULT(S): A total of 1,281 ASD patients (60.2 yrs, 73.5% F, 28 kg/m2) were included. A total of 49.4% of procedures involved decompression and 100% involved fusion, with a mean number of levels fused of 10.98. The means for individual patient characteristics that coincide with the variables entered into the online risk calculator interface are as follows: functional status through baseline ODI scores (Independent [0-40]: 35.6%, Partially Dependent [41-80]: 61.8%, Totally Dependent [81+]: 2.6%), 0% emergent cases, ASA Class (I: 5.6%, II: 46.8%, III: 41.7%, IV: 1.4%, V: 0%), 11.9% disseminated cancer, 9.1% diabetes mellitus, 36.5% use of hypertensive medications, 10.8% CHF, 5.9% current smoker, 5.2% COPD, and 4.4% acute renal failure. Predictive of any 30-day postoperative complications ranged from 2.8-18.5% across CPT codes, where the actual rate in the cohort was 9.0%, and demonstrated good predictive performance via Brier Score (0.00064516, Max: 0.00819), as well as pneumonia, SSI, UTI, VTE, renal failure, death and sepsis (Brier Max: 0-0.01458096). Serious and cardiac complications, as well as return to OR were poorly predicted via the NSQIP risk index (Brier Max > 0.05). Mean difference between observed and predicted LOS was 4.276 days with a 95% confidence interval of 9.484 - -0.932. When indicated for significantly high risk, the calculator poorly predicted overall and serious complications (Brier Max >0.1).
CONCLUSION(S): While the ACS-NSQIP risk index had acceptable predictive performance in regards to the occurrence of overall post-operative complications, notable exceptions were detected. Specifically, deficiencies in assessing serious complications, cardiac complication and return to OR were seen, and performance was noted to diminish with procedures of greater invasiveness. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Recent studies have suggested that for patients with chronic neck pain, both psychological and physical symptoms need to be addressed. Studies have shown that psychological distress is associated with poor outcomes in these patients. The fear avoidance model has been used to explain how maladaptive thoughts and behaviors contribute to chronicity and disability. Cognitive behavioral therapy (CBT) addresses these risk factors through education about pain, modification of maladaptive beliefs, and increasing patient's self-efficacy. PURPOSE: Determine the effectiveness of brief psychological intervention on psychological outcomes in cervical spine surgery. STUDY DESIGN/SETTING: Prospective, blind, and placebo-controlled trial. PATIENT SAMPLE: A total of 42 symptomatic Cervical Degenerative Disorders patients. OUTCOME MEASURES: Distress and Risk Assessment Method (DRAM), Fear Avoidance Beliefs Questionnaire (FABQ), Pain Catastrophizing Scale (PCS), Outcome Expectation Question (OEQ). Neck Disability Index (NDI), modified Japanese Orthopedic Association (mJOA).
METHOD(S): Forty-two patients age >18 with symptomatic cervical degenerative disease have been enrolled in the study. If patients met psychological distress criteria, they were in the treatment group: DRAM >17 and <33, FABQ >49/66, PCS >30/52 or OEQ <=2 (randomized to CBT or Placebo). CBT and Placebo treatment groups had 6 sessions prior to surgery. The control group had no intervention prior to surgery. Baseline and 1-year (1Y) changes were assessed for all outcome measures.
RESULT(S): Forty-two patients were enrolled (53.6 years, BMI 29.4 kg/m2); 23 patients met psychological distress criteria and were randomized into a treatment group (14 CBT vs 9 placebo). Ten patients were in the control group, with nine exceeding DRAM scores to be CBT candidates. At enrollment, the CBT group had greater EQ5D scores (CBT: 10.8, Placebo: 9.5, Control: 7.5, DRAM:8.7) while the Placebo group had greater PCS scores (Placebo: 33.1, CBT: 32.4, Control:18.6, DRAM: 30.8; all p<0.05). From BL to 1Y postop, the CBT patients improved in all psychological-related questionnaires (NDI: 29.2 to 2, PCS: 32.4 to 20.7, FABQ:41.3 to 32.3, mJOA: 2.3 to 3.4, DRAM:12.9 to 16.6). Placebo patients also improved post-operatively, but to a lesser degree in NDI (26.6 to 2), PCS (33.1 to 28.3), and worsened in FABQ (40.4 to 54.1), mJOA(12.5 to 11.8), and DRAM (36.6 to 31.6). In contrast, patients in the control group showed improvement to a much lesser degree than CBT and Placebo patients (NDI: 18.1 to 2, PCS:18.6 to 3.2, FABQ:26.2 to 17.6, mJOA: 15.3 to 16.4). DRAM patients showed minimal changes in psychological- and spine-related questionnaires. Comparing treatment groups at 1Y, CBT pts had significantly lower FABQ scores than Placebo pts (32.3 vs 54.1; p<0.05). CBT pts also had better DRAM scores than the control group at 1Y (30.3 vs 11.4; p=0.03).
CONCLUSION(S): Cognitive behavior treatment can be beneficial in patients undergoing cervical surgery as it was identified in our study to minimize fear avoidance beliefs more than the Placebo group. This type of professional treatment has also shown a steady improvement in all psychological questionnaires and spine related neck disability from baseline to 1-year postoperatively. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Little is known of the impact of myelopathy severity in patients undergoing cervical deformity (CD) on postoperative patient-reported outcomes when stratified by baseline deformity severity. PURPOSE: To investigate the impact of myelopathy severity on outcomes and satisfaction post-operatively over baseline deformity severity. STUDY DESIGN/SETTING: Retrospective cohort study of a single-surgeon CD database PATIENT SAMPLE: A total of 128 CD Patients. OUTCOME MEASURES: HRQL Instruments: Neck Disability Index [NDI], Euro-Qol 5-Dimension questionnaire [EQ5D], meeting the Minimal Clinically Important Difference [MCID]; complications; reoperations METHODS: Included: surgical adult CD patients (C2-C7 Cobb>10degree, CL>10degree, cSVA >4cm, or CBVA>25degree) with baseline and 1-year HRQLs and radiographic follow-up. The modified Japanese Orthopaedic Association scale [mJOA] was utilized to assess baseline myelopathy severity (mJOA=18 was excluded). Moderate myelopathy: 12-17 mJOA scores at baseline; Severe myelopathy: <12 mJOA. Moderate deformity: <=25degree TS-CL at baseline; Severe deformity: >25degree. TS-CL. Groups assessed: (1) severe myelopathy/deformity, (2) severe myelopathy and moderate deformity, (3) moderate myelopathy/deformity, (4) moderate myelopathy and severe deformity. Groups 2 and 4 were compared as mismatched groups. Univariate analyses were performed with a statistical cut-off p<0.050 to determine whether myelopathy severity or deformity severity had a greater impact on patient-reported outcomes.
RESULT(S): A total of 128 CD patients were included (56.5+/-9.2 years, 46% female, 30.4+/-6.4kg/m2). The average Charlson Comorbidity Index (CCI) score was 0.56, 18% current smokers. Cohort surgical factors included, by approach, 27.9% anterior, 47.5% posterior and 24.6% combined (mean levels fused: 5). Mean total operative time was 588.5 minutes, with an EBL of 766.9ccs. Baseline mJOA score was 12.8+/-2.7, with a mean TS-CL of 25.9+/-16.1degree. 30.5% of patients had severe baseline myelopathy, 69.5% Moderate mJOA. By baseline deformity severity, 35.2% were Moderate TS-CL, while 64.8% Severe. By myelopathy/deformity groups: (1) 11.1%, (2) 21%, (3) 34.6%, (4) 33.3%. At baseline, NDI score was the greatest in Group 2 at 69.4 (1: 69.1, 3: 57.1, 4: 52.6, p = 0.011), whereas Group 4 had the lowest EQ5D scores (p<0.001). According to baseline neurologic exam factors were significantly greater in the groups with severe myelopathy (1 and 2, p<0.050). At one year, 55.6% of patients with severe myelopathy and severe deformity (Group 1) met MCID for NDI, while 6.9% of Group 2, 25% Group 3, and 55.6% Group 4, p= 0.002. Mismatch myelopathy/deformity analysis determined that a greater myelopathy over deformity (Group 2) had significantly worse patient reported outcomes compared to Group 4 in terms of 1-year NDI (2: 57 vs 4: 28.1; p=0.004), EQ5D(p=0.028), and NRS Neck (2:5.9, 4:3.6; p=0.046), as well as meeting MCID for NDI (2: 5.9%, 4: 55.6%; p=0.001).
CONCLUSION(S): Patients who present with moderate deformity and severe myelopathy have worse patient-reported outcomes compared to patients classified with severe deformity and moderate myelopathy. In moderate deformity, the myelopathy decompression and symptomatic alleviation plays more of a role, but, most importantly, in severe deformity, decompression is inadequate and realignment is necessary due to cord tension. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Spinal fusion is increasingly considered for management of patients with osteoporosis (OP) and degenerative disc disease (DDD). Little data is available regarding long-term outcomes in OP patients undergoing short-segment, lumbar fusion for DDD. PURPOSE: Analyze the impact of OP on long-term outcomes in patients who have had 2-3-level lumbar fusions for degenerative disc disease. STUDY DESIGN/SETTING: Retrospective review of the New York State Statewide Planning and Research Cooperative System (NYS SPARCS) database. PATIENT SAMPLE: Patients with DDD undergoing 2-3-level lumbar fusion. OUTCOME MEASURES: Frequency of 2-year medical and surgical complications and reoperations.
METHOD(S): Utilizing SPARCS, all patients from 2009-2011 with ICD-9 codes for DDD who underwent 2-3-level lumbar fusion were identified. Patients with bone mineralization disorders, systemic and endocrine disorders affecting bone quality were excluded. Surgical indications of trauma, systemic disease(s), and infection were excluded. Patients with and without OP were compared for demographics, hospital-related parameters, and 2-year complications and reoperations. Logistic regression models were utilized to identify predictors of complications.
RESULT(S): A total of 29,028 patients (OP=1,353 (4.7%), No-OP=27,675) were included. OP patients were older (66.9 vs 52.6 years) as well as more often female (85.1% vs 48.4%) and white (82.8% vs 73.5%), all p<0.001. Deyo index did not differ between groups. LOS and total charges were higher for OP patients (4.9 vs 4.1 days; $74,484 vs $73,724), all p<0.001. Medical complications were higher for OP patients: acute renal failure (8.9% vs 4.7%), and deep vein thromboses (3.4% vs 1.6%), all p<0.01. OP patients also had higher rates of implant-related (3.4% vs 1.9%) and wound complications (9.8% vs 5.9%) (p<0.01). Preoperative OP was associated with 2-year medical and surgical complications (OR=1.62, 1.66; p<0.001). Patients with OP had greater odds of reoperations (OR=1.34).
CONCLUSION(S): Patients with OP undergoing 2-3-level lumbar fusion for DDD were at higher risk of 2-year medical and surgical complications, and 3.4% of OP patients experienced implant-related complication. These findings highlight the importance of rigorous preoperative metabolic workup prior to spinal surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: With the increasing emphasis on value-based outcomes in health care, there has been an increased focus on the cost of surgical intervention in patients with adult spinal deformity (ASD). However, there is a paucity of literature on the economic impact of a surgeon's surgical approach for corrective ASD surgery. PURPOSE: To investigate the cost-utility associated with surgical approach. STUDY DESIGN/SETTING: Retrospective cohort study of a prospective multicenter ASD database. PATIENT SAMPLE: This study included 208 ASD patients. OUTCOME MEASURES: Oswestry Disability Index (ODI), SF-6D, cost per quality adjusted life years (QALY).
METHOD(S): ASD patients with no previous history of fusions, complete radiographic, and HRQL data at baseline and 2 years were included. Patients were propensity score matched for age, CCI, levels fused, frailty, SVA, PI-LL and osteotomies. Means comparison tests and ANOVA chi-squared analyses assessed differences in baseline demographic and clinical data between cohorts. Utility data were calculated using ODI converted to SF-6D using published conversion methods. QALYs utilized a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs were calculated using the PearlDiver database incorporating complications, comorbidities (CC), major complications, and comorbidities (MCC) were assessed according to CMS.gov manual definitions. Two-year reimbursement consisted of a standardized estimate using regression analysis of Medicare pay-scales for all services rendered within a 30-day window, including estimates regarding costs of postoperative complications, outpatient health care encounters, revisions and medical related readmissions. After accounting for CC, MCC, length of stay (LOS), revisions, and death, cost per QALY at 2 years and life expectancy were calculated for surgical approach.
RESULT(S): A total of 208 PSM ASD patients were included (62.2yrs, 84% F, 26.9 kg/m²). Patients undergoing a combined approach had a longer LOS (6.55 vs 8.15), greater operative time, and experienced significantly greater blood loss (all p<0.05). Posterior-only approach patients had significantly higher rates of operative complications and revisions within 2 years of index surgery (both p<0.05). Overall, posterior vs combined patients did not significantly differ at baseline ODI (44.3 vs 41.5, p>0.05). Despite initial higher costs of a combined approach, the average cost of ASD surgery at 2 years follow-up for posterior-only approach was greater compared to a combined approach ($72,749 vs $65,073). Furthermore, the cost per QALY was higher for posterior-only patients at 2 years compared to patients undergoing a combined approach ($363,910 vs $333,981). If utility gained is sustained to life expectancy, the cost per QALY was $54,027 for posterior-only and $49,584 for combined.
CONCLUSION(S): In a matched cohort of adult spinal deformity patients, a combined approach trended toward a lower average cost of surgery at 2 years, lower cost per QALY, significantly lower rates of operative complications and revisions. Although improvement after surgical intervention was similar between the two approaches, cost per QALY of posterior-only approach was slightly greater primarily driven by increased operative complications and rates of revisions. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Proximal junctional failure (PJF) is a common and particularly adverse complication of adult spinal deformity (ASD) surgery. There is evidence that the rigidity of posterior spinal constructs may impact risk of PJF. PURPOSE: We hypothesized that lower mean screws per level and decreased rod stiffness would be associated with lower incidence of PJF. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: Patients with ASD and 2-year minimum follow-up were included. Only patients undergoing fusion of >=5 levels, and with LIV at the sacro-pelvis were included. Patients undergoing revision surgery were excluded. In total, 420 patients were analyzed. OUTCOME MEASURES: The primary outcome variable was PJF, defined using previously published radiographic criteria (PJ angle >28degreeand PJ angle >22degree, and >=8mm/>=3mm listhesis at upper thoracic / thoracolumbar levels, respectively).
METHOD(S): The primary independent variables were the mean number of screws per level fused analyzed with a cutoff of 1.8 (determined by ROC analysis) and rod material/diameter. Multivariable logistic regression was utilized to investigate confounding factors, including age, history of osteoporosis, BMI, gender, CCI, preoperative Schwab modifiers, preoperative TPA, postoperative change in lumbar lordosis, upper instrumented vertebra, osteotomy, approach, UIV type (ie, pedicle screw vs other), and number of levels fused.
RESULT(S): Of the total patients, 78.8% were female. PJF occurred in 14.1% of patients. The mean screws per level was 1.7 (SD 0.2), and 57.6% of patients had <1.8 screws per level. PJF occurred in 19.4% vs 9.8% of patients with >=1.8 vs <1.8 screws per level, respectively (p<0.01). In multivariable analysis, patients with <1.8 screws per level exhibited lower odds of PJF (OR 0.39, p<0.01). Rod material and diameter (both p>0.2) were not significantly associated with PJF. Screw density specifically adjacent to the UIV was not related to PJF (p>0.2).
CONCLUSION(S): Among ASD patients undergoing long-segment primary fusion to the pelvis, the risk of PJF was lower among patients with <1.8 screws per level. Rod diameter and material, however, were not significantly associated with PJF. This finding may be related to construct rigidity. It is possible that residual confounding by other patient and surgeon-specific characteristics may exist. Further biomechanical and clinical studies exploring the relationship between screw density and PJK/PJF are warranted. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT/BACKGROUND:Considerable debate exists regarding the optimal surgical approach for adult spinal deformity (ASD). It remains unclear which approach, posterior-only or combined anterior-posterior (AP), is more cost-effective. Our goal is to determine the 2-year cost per quality-adjusted life year (QALY) for each approach. PURPOSE/OBJECTIVE:To compare the 2-year cost-effectiveness of surgical treatment for ASD between the posterior-only approach and combined AP approach. STUDY DESIGN/METHODS:Retrospective economic analysis of a prospective, multicenter database PATIENT SAMPLE: From a prospective, multicenter surgical database of ASD, patients undergoing 5 or more level fusions through a posterior-only or AP approach were identified and compared. METHODS:QALYs gained were determined using baseline, 1-year, and 2-year post-operative Short Form 6D. Cost was calculated from actual, direct hospital costs including any subsequent readmission or revision. Cost-effectiveness was determined using cost/QALY gained. RESULTS:The AP approach showed significantly higher index cost than the posterior-only approach ($84,329 vs $64,281). This margin decreased at 2-year follow-up with total costs of $89,824 and $73,904, respectively. QALYs gained at two years were similar with 0.21 and 0.17 in the posterior-only and the AP approaches, respectively. The cost/QALY at two years after surgery was significantly higher in the AP approach ($525,080) than in the posterior-only approach ($351,086). CONCLUSIONS:We assessed 2-year cost-effectiveness for the surgical treatment through posterior-only and AP approaches. The posterior-only approach is less expensive both for the index surgery and at 2-year follow-up. The QALY gained at 2-years was similar between the two approaches. Thus, posterior-only approach was more cost-effective than the AP approach under our study parameters. However, both approaches were not cost-effective at 2-year follow-up.