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Alexander A. Theologis, Gregory M. Mundis Jr., Stacie Nguyen, David O. Okonkwo, Praveen V. Mummaneni, Justin S. Smith, Christopher I. Shaffrey, Richard Fessler, Shay Bess, Frank Schwab, Bassel G. Diebo, Douglas Burton, Robert Hart, Vedat Deviren and Christopher Ames


The aim of this study was to evaluate the utility of supplementing long thoracolumbar posterior instrumented fusion (posterior spinal fusion, PSF) with lateral interbody fusion (LIF) of the lumbar/thoracolumbar coronal curve apex in adult spinal deformity (ASD).


Two multicenter databases were evaluated. Adults who had undergone multilevel LIF of the coronal curve apex in addition to PSF with L5–S1 interbody fusion (LS+Apex group) were matched by number of posterior levels fused with patients who had undergone PSF with L5–S1 interbody fusion without LIF (LS-Only group). All patients had at least 2 years of follow-up. Percutaneous PSF and 3-column osteotomy (3CO) were excluded. Demographics, perioperative details, radiographic spinal deformity measurements, and HRQoL data were analyzed.


Thirty-two patients were matched (LS+Apex: 16; LS: 16) (6 men, 26 women; mean age 63 ± 10 years). Overall, the average values for measures of deformity were as follows: Cobb angle > 40°, sagittal vertical axis (SVA) > 6 cm, pelvic tilt (PT) > 25°, and mismatch between pelvic incidence (PI) and lumbar lordosis (LL) > 15°. There were no significant intergroup differences in preoperative radiographic parameters, although patients in the LS+Apex group had greater Cobb angles and less LL. Patients in the LS+Apex group had significantly more anterior levels fused (4.6 vs 1), longer operative times (859 vs 379 minutes), and longer length of stay (12 vs 7.5 days) (all p < 0.01). For patients in the LS+Apex group, Cobb angle, pelvic tilt (PT), lumbar lordosis (LL), PI-LL (lumbopelvic mismatch), Oswestry Disability Index (ODI) scores, and visual analog scale (VAS) scores for back and leg pain improved significantly (p < 0.05). For patients in the LS-Only group, there were significant improvements in Cobb angle, ODI score, and VAS scores for back and leg pain. The LS+Apex group had better correction of Cobb angles (56% vs 33%, p = 0.02), SVA (43% vs 5%, p = 0.46), LL (62% vs 13%, p = 0.35), and PI-LL (68% vs 33%, p = 0.32). Despite more LS+Apex patients having major complications (56% vs 13%; p = 0.02) and postoperative leg weakness (31% vs 6%, p = 0.07), there were no intergroup differences in 2-year outcomes.


Long open posterior instrumented fusion with or without multilevel LIF is used to treat a variety of coronal and sagittal adult thoracolumbar deformities. The addition of multilevel LIF to open PSF with L5–S1 interbody support in this small cohort was often used in more severe coronal and/or lumbopelvic sagittal deformities and offered better correction of major Cobb angles, lumbopelvic parameters, and SVA than posterior-only operations. As these advantages came at the expense of more major complications, more leg weakness, greater blood loss, and longer operative times and hospital stays without an improvement in 2-year outcomes, future investigations should aim to more clearly define deformities that warrant the addition of multilevel LIF to open PSF and L5–S1 interbody fusion.

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Darryl Lau, Andrew K. Chan, Alexander A. Theologis, Dean Chou, Praveen V. Mummaneni, Shane Burch, Sigurd Berven, Vedat Deviren and Christopher Ames


Because the surgical strategies for primary and metastatic spinal tumors are different, the respective associated costs and morbidities associated with those treatments likely vary. This study compares the direct costs and 90-day readmission rates between the resection of extradural metastatic and primary spinal tumors. The factors associated with cost and readmission are identified.


Adults (age 18 years or older) who underwent the resection of spinal tumors between 2008 and 2013 were included in the study. Patients with intradural tumors were excluded. The direct costs of index hospitalization and 90-day readmission hospitalization were evaluated. The direct costs were compared between patients who were treated surgically for primary and metastatic spinal tumors. The independent factors associated with costs and readmissions were identified using multivariate analysis.


A total of 181 patients with spinal tumors were included (63 primary and 118 metastatic tumors). Overall, the mean index hospital admission cost for the surgical management of spinal tumors was $52,083. There was no significant difference in the cost of hospitalization between primary ($55,801) and metastatic ($50,098) tumors (p = 0.426). The independent factors associated with higher cost were male sex (p = 0.032), preoperative inability to ambulate (p = 0.002), having more than 3 comorbidities (p = 0.037), undergoing corpectomy (p = 0.021), instrumentation greater than 7 levels (p < 0.001), combined anterior-posterior approach (p < 0.001), presence of a perioperative complication (p < 0.001), and longer hospital stay (p < 0.001). The perioperative complication rate was 21.0%. Of this cohort, 11.6% of patients were readmitted within 90 days, and the mean hospitalization cost of that readmission was $20,078. Readmission rates after surgical treatment for primary and metastatic tumors were similar (11.1% vs 11.9%, respectively) (p = 0.880). Prior hospital stay greater than 15 days (OR 6.62, p = 0.016) and diagnosis of lung metastasis (OR 52.99, p = 0.007) were independent predictors of readmission.


Primary and metastatic spinal tumors are comparable with regard to the direct costs of the index surgical hospitalization and readmission rate within 90 days. The factors independently associated with costs are related to preoperative health status, type and complexity of surgery, and postoperative course.

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Beejal Y. Amin, Tsung-Hsi Tu, William W. Schairer, Lumine Na, Steven Takemoto, Sigurd Berven, Vedat Deviren, Christopher Ames, Dean Chou and Praveen V. Mummaneni


Administrative databases are increasingly being used to establish benchmarks for quality of care and to compare performance across peer hospitals. As proposals for accountable care organizations are being developed, readmission rates will be increasingly scrutinized. The purpose of the present study was to assess whether the all-cause readmissions rate appropriately reflects the University of California, San Francisco (UCSF) Medical Center hospital's clinically relevant readmission rate for spine surgery patients and to identify predictors of readmission.


Data for 5780 consecutive patient encounters managed by 10 spine surgeons at UCSF Medical Center from October 2007 to June 2011 were abstracted from the University HealthSystem Consortium (UHC) using the Clinical Data Base/Resource Manager. Of these 5780 patient encounters, 281 patients (4.9%) were rehospitalized within 30 days of the previous discharge date. The authors performed an independent chart review to determine clinically relevant reasons for readmission and extracted hospital administrative data to calculate direct costs. Univariate logistic regression analysis was used to evaluate possible predictors of readmission. The two-sample t-test was used to examine the difference in direct cost between readmission and nonreadmission cases.


The main reasons for readmission were infection (39.8%), nonoperative management (13.4%), and planned staged surgery (12.4%). The current all-cause readmission algorithm resulted in an artificially high readmission rate from the clinician's point of view. Based on the authors' manual chart review, 69 cases (25% of the 281 total readmissions) should be excluded because 39 cases (13.9%) were planned staged procedures; 16 cases (5.7%) were unrelated to spine surgery; and 14 surgical cases (5.0%) were cancelled or rescheduled at index admission due to unpredictable reasons. When these 69 cases are excluded, the direct cost of readmission is reduced by 29%. The cost variance is in excess of $3 million. Predictors of readmission were admission status (p < 0.0001), length of stay (p = 0.0001), risk of death (p < 0.0001), and age (p = 0.021).


The authors' findings identify the potential pitfalls in the calculation of readmission rates from administrative data sets. Benchmarking algorithms for defining hospitals' readmission rates must take into account planned staged surgery and eliminate unrelated reasons for readmission. When this is implemented in the calculation method, the readmission rate will be more accurate. Current tools overestimate the clinically relevant readmission rate and cost.