Browsing by Author "Naessig, Sara"
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Item Open Access Adult cervical spine deformity: a state-of-the-art review.(Spine Deform, 2023-09-30) Jackson-Fowl, Brendan; Hockley, Aaron; Naessig, Sara; Ahmad, Waleed; Pierce, Katherine; Smith, Justin S; Ames, Christopher; Shaffrey, Christopher; Bennett-Caso, Claudia; Williamson, Tyler K; McFarland, Kimberly; Passias, Peter GAdult cervical deformity is a structural malalignment of the cervical spine that may present with variety of significant symptomatology for patients. There are clear and substantial negative impacts of cervical spine deformity, including the increased burden of pain, limited mobility and functionality, and interference with patients' ability to work and perform everyday tasks. Primary cervical deformities develop as the result of a multitude of different etiologies, changing the normal mechanics and structure of the cervical region. In particular, degeneration of the cervical spine, inflammatory arthritides and neuromuscular changes are significant players in the development of disease. Additionally, cervical deformities, sometimes iatrogenically, may present secondary to malalignment or correction of the thoracic, lumbar or sacropelvic spine. Previously, classification systems were developed to help quantify disease burden and influence management of thoracic and lumbar spine deformities. Following up on these works and based on the relationship between the cervical and distal spine, Ames-ISSG developed a framework for a standardized tool for characterizing and quantifying cervical spine deformities. When surgical intervention is required to correct a cervical deformity, there are advantages and disadvantages to both anterior and posterior approaches. A stepwise approach may minimize the drawbacks of either an anterior or posterior approach alone, and patients should have a surgical plan tailored specifically to their cervical deformity based upon symptomatic and radiographic indications. This state-of-the-art review is based upon a comprehensive overview of literature seeking to highlight the normal cervical spine, etiologies of cervical deformity, current classification systems, and key surgical techniques.Item Open Access At What Point Should the Thoracolumbar Region Be Addressed in Patients Undergoing Corrective Cervical Deformity Surgery?(Spine, 2021-10) Passias, Peter G; Pierce, Katherine E; Naessig, Sara; Ahmad, Waleed; Passfall, Lara; Lafage, Renaud; Lafage, Virginie; Kim, Han Jo; Daniels, Alan; Eastlack, Robert; Klineberg, Eric; Line, Breton; Mummaneni, Praveen; Hart, Robert; Burton, Douglas; Bess, Shay; Schwab, Frank; Shaffrey, Christopher; Smith, Justin S; Ames, Christopher P; International Spine Study GroupStudy design
Retrospective cohort study.Objective
The aim of this study was to investigate the impact of cervical to thoracolumbar ratios on poor outcomes in cervical deformity (CD) corrective surgery.Summary of background data
Consideration of distal regional and global alignment is a critical determinant of outcomes in CD surgery. For operative CD patients, it is unknown whether certain thoracolumbar parameters play a significant role in poor outcomes and whether addressing such parameters is warranted.Methods
Included: surgical CD patients (C2-C7 Cobb >10°, cervical lordosis [CL] >10°, C2-C7 sagittal vertical axis (cSVA) >4 cm, or chin-brow vertical angle >25°) with baseline and 1-year data. Patients were assessed for ratios of preop cervical and global parameters including: C2 Slope/T1 slope, T1 slope minus C2-C7 lordosis (TS-CL)/mismatch between pelvic incidence and lumbar lordosis (PI-LL), cSVA/sagittal vertical axis (SVA). Deformity classification ratios of cervical (Ames-ISSG) to spinopelvic (SRS-Schwab) were investigated: cSVA modifier/SVA modifier, TS-CL modifier/PI-LL modifier. Cervical to thoracic ratios included C2-C7 lordosis/T4-T12 kyphosis. Correlations assessed the relationship between ratios and poor outcomes (major complication, reoperation, distal junctional kyphosis (DJK), or failure to meet minimal clinically important difference [MCID]). Decision tree analysis through multiple iterations of multivariate regressions assessed cut-offs for ratios for acquiring suboptimal outcomes.Results
A total of 110 CD patients were included (61.5 years, 66% F, 28.8 kg/m2). Mean preoperative radiographic ratios calculated: C2 slope/T1 slope of 1.56, TS-CL/PI-LL of 11.1, cSVA/SVA of 5.4, CL/thoracic kyphosis (TK) of 0.26. Ames-ISSG and SRS-Schwab modifier ratios: cSVA/SVA of 0.1 and TS-CL/PI-LL of 0.35. Pearson correlations demonstrated a relationship between major complications and baseline TS-CL/PI-LL, Ames TS-CL/Schwab PI-LL modifiers, and the CL/TK ratios (P < 0.050). Reoperation had significant correlation with TS-CL/PI-LL and cSVA/SVA ratios. Postoperative DJK correlated with C2 slope/T1 slope and CL/TK ratios. Not meeting MCID for Neck Disability Index (NDI) correlated with CL/TK ratio and not meeting MCID for EQ5D correlated with Ames TS-CL/Schwab PI-LL.Conclusion
Consideration of cervical to global alignment is a critical determinant of outcomes in CD corrective surgery. Key ratios of cervical to global alignment correlate with suboptimal clinical outcomes. A larger cervical lordosis to TK predicted postoperative complication, DJK, and not meeting MCID for NDI.Level of Evidence: 4.Item Open Access Baseline Frailty Status Influences Recovery Patterns and Outcomes Following Alignment Correction of Cervical Deformity.(Neurosurgery, 2021-05) Pierce, Katherine E; Passias, Peter G; Daniels, Alan H; Lafage, Renaud; Ahmad, Waleed; Naessig, Sara; Lafage, Virginie; Protopsaltis, Themistocles; Eastlack, Robert; Hart, Robert; Burton, Douglas; Bess, Shay; Schwab, Frank; Shaffrey, Christopher; Smith, Justin S; Ames, ChristopherBackground
Frailty severity may be an important determinant for impaired recovery after cervical spine deformity (CD) corrective surgery.Objective
To evaluate postop clinical recovery among CD patients between frailty states undergoing primary procedures.Methods
Patients >18 yr old undergoing surgery for CD with health-related quality of life (HRQL) data at baseline, 3-mo, and 1-yr postoperative were identified. Patients were stratified by the modified CD frailty index scale from 0 to 1 (no frailty [NF] <0.3, mild/severe fraily [F] >0.3). Patients in NF and F groups were propensity score matched for TS-CL (T1 slope [TS] minus angle between the C2 inferior end plate and the C7 inferior end plate [CL]) to control for baseline deformity. Area under the curve was calculated for follow-up time intervals determining overall normalized, time-adjusted HRQL outcomes; Integrated Health State (IHS) was compared between NF and F groups.Results
A total of 106 CD patients were included (61.7 yr, 66% F, 27.7 kg/m2)-by frailty group: 52.8% NF, 47.2% F. After propensity score matching for TS-CL (mean: 38.1°), 38 patients remained in each of the NF and F groups. IHS-adjusted HRQL outcomes from baseline to 1 yr showed a significant difference in Euro-Qol 5 Dimension scores (NF: 1.02, F: 1.07, P = .016). No significant differences were found in the IHS Neck Disability Index (NDI) and modified Japanese Orthopedic Association between frailty groups (P > .05). F patients had more postop major complications (31.3%) compared to the NF (8.9%), P = .004, though DJK occurrence and reoperation between the groups was not significant.Conclusion
While all groups exhibited improved postop disability and pain scores, frail patients experienced greater amount of improvement in overall health state compared to baseline disability. This signifies that with frailty severity, patients have more room for improvement postop compared to baseline quality of life.Item Open Access Compensation from mild and severe cases of early proximal junctional kyphosis may manifest as progressive cervical deformity at two year follow-up.(Spine deformity, 2023-12) Passias, Peter G; Naessig, Sara; Williamson, Tyler K; Lafage, Renaud; Lafage, Virginie; Smith, Justin S; Gupta, Munish C; Klineberg, Eric; Burton, Douglas C; Ames, Christopher; Bess, Shay; Shaffrey, Christopher; Schwab, Frank J; International Spine Study Group (ISSG)Background
Postoperative reciprocal changes (RC) in the cervical spine associated with varying factors of proximal junctional kyphosis (PJK) following fusions of the thoracopelvic spine are poorly understood.Purpose
Explore reciprocal changes in the cervical spine associated with varying factors (severity, progression, patient age) of PJK in patients undergoing adult spinal deformity (ASD) correction.Patients and methods
Retrospective review of a multicenter ASD database.Inclusion
ASD patients > 18 y/o, undergoing fusions from the thoracic spine (UIV: T6-T12) to the pelvis with two-year radiographic data. ASD was defined as: Coronal Cobb angle ≥ 20°, Sagittal Vertical Axis ≥ 5 cm, Pelvic Tilt ≥ 25°, and/or Thoracic Kyphosis ≥ 60°. PJK was defined as a ≥ 10° measure of the sagittal Cobb angle between the inferior endplate of the UIV and the superior endplate of the UIV + 2. Patients were grouped by mild (M; 10°-20°) and severe (S; > 20°) PJK at one year. Propensity Score Matching (PSM) controlled for CCI, age, PI and UIV. Unpaired and paired t test analyses determined difference between RC parameters and change between time points. Pearson bi-variate correlations analyzed associations between RC parameters (T4-T12, TS-CL, cSVA, C2-Slope, and T1-Slope) and PJK descriptors.Results
284 ASD patients (UIV: T6: 1.1%; T7: 0.7%; T8: 4.6%; T9: 9.9%; T10: 58.8%; T11: 19.4%; T12: 5.6%) were studied. PJK analysis consisted of 182 patients (Mild = 91 and Severe = 91). Significant difference between M and S groups were observed in T4-T12 Δ1Y(- 16.8 v - 22.8, P = 0.001), TS-CLΔ1Y(- 0.6 v 2.8, P = 0.037), cSVAΔ1Y(- 1.8 v 1.9, P = 0.032), and C2 slopeΔ1Y(- 1.6 v 2.3, P = 0.022). By two years post-op, all changes in cervical alignment parameters were similar between mild and severe groups. Correlation between age and cSVAΔ1Y(R = 0.153, P = 0.034) was found. Incidence of severe PJK was found to correlate with TS-CLΔ1Y(R = 0.142, P = 0.049), cSVAΔ1Y(R = 0.171, P = 0.018), C2SΔ1Y(R = 0.148, P = 0.040), and T1SΔ2Y(R = 0.256, P = 0.003).Conclusions
Compensation within the cervical spine differed between individuals with mild and severe PJK at one year postoperatively. However, similar levels of pathologic change in cervical alignment parameters were seen by two years, highlighting the progression of cervical compensation due to mild PJK over time. These findings provide greater evidence for the development of cervical deformity in individuals presenting with proximal junctional kyphosis.Item Open Access Development of Risk Stratification Predictive Models for Cervical Deformity Surgery.(Neurosurgery, 2022-12) Passias, Peter G; Ahmad, Waleed; Oh, Cheongeun; Imbo, Bailey; Naessig, Sara; Pierce, Katherine; Lafage, Virginie; Lafage, Renaud; Hamilton, D Kojo; Protopsaltis, Themistocles S; Klineberg, Eric O; Gum, Jeffrey; Schoenfeld, Andrew J; Line, Breton; Hart, Robert A; Burton, Douglas C; Bess, Shay; Schwab, Frank J; Smith, Justin S; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study GroupBackground
As corrective surgery for cervical deformity (CD) increases, so does the rate of complications and reoperations. To minimize suboptimal postoperative outcomes, it is important to develop a tool that allows for proper preoperative risk stratification.Objective
To develop a prognostic utility for identification of risk factors that lead to the development of major complications and unplanned reoperations.Methods
CD patients age 18 years or older were stratified into 2 groups based on the postoperative occurrence of a revision and/or major complication. Multivariable logistic regressions identified characteristics that were associated with revision or major complication. Decision tree analysis established cutoffs for predictive variables. Models predicting both outcomes were quantified using area under the curve (AUC) and receiver operating curve characteristics.Results
A total of 109 patients with CD were included in this study. By 1 year postoperatively, 26 patients experienced a major complication and 17 patients underwent a revision. Predictive modeling incorporating preoperative and surgical factors identified development of a revision to include upper instrumented vertebrae > C5, lowermost instrumented vertebrae > T7, number of unfused lordotic cervical vertebrae > 1, baseline T1 slope > 25.3°, and number of vertebral levels in maximal kyphosis > 12 (AUC: 0.82). For developing a major complication, a model included a current smoking history, osteoporosis, upper instrumented vertebrae inclination angle < 0° or > 40°, anterior diskectomies > 3, and a posterior Smith Peterson osteotomy (AUC: 0.81).Conclusion
Revisions were predicted using a predominance of radiographic parameters while the occurrence of major complications relied on baseline bone health, radiographic, and surgical characteristics.Item Open Access Effect of age-Adjusted alignment goals and distal inclination angle on the fate of distal junctional kyphosis in cervical deformity surgery(Journal of Craniovertebral Junction and Spine, 2021-01-01) Passias, Peter Gust; Horn, Samantha R; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Line, Breton G; Protopsaltis, Themistocles S; Soroceanu, Alex; Bortz, Cole; Segreto, Frank A; Ahmad, Waleed; Naessig, Sara; Pierce, Katherine E; Brown, Avery E; Alas, Haddy; Kim, Han Jo; Daniels, Alan H; Klineberg, Eric O; Burton, Douglas C; Hart, Robert A; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study GroupBackground: Age-Adjusted alignment targets in the context of distal junctional kyphosis (DJK) development have yet to be investigated. Our aim was to assess age-Adjusted alignment targets, reciprocal changes, and role of lowest instrumented level orientation in DJK development in cervical deformity (CD) patients. Methods: CD patients were evaluated based on lowest fused level: cervical (C7 or above), upper thoracic (UT: T1-T6), and lower thoracic (LT: T7-T12). Age-Adjusted alignment targets were calculated using published formulas for sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis (PI-LL), pelvic tilt (PT), T1 pelvic angle (TPA), and LL-Thoracic kyphosis (TK). Outcome measures were cervical and global alignment parameters: Cervical SVA (cSVA), cervical lordosis, C2 slope, C2-T3 angle, C2-T3 SVA, TS-CL, PI-LL, PT, and SVA. Subanalysis matched baseline PI to assess age-Adjusted alignment between DJK and non-DJK. Results: Seventy-six CD patients included. By 1Y, 20 patients developed DJK. Non-DJK patients had 27% cervical lowest instrumented vertebra (LIV), 68% UT, and 5% LT. DJK patients had 25% cervical, 50% UT, and 25% LT. There were no baseline or 1Y differences for PI, PI-LL, SVA, TPA, or PT for actual and age-Adjusted targets. DJK patients had worse baseline cSVA and more severe 1Y cSVA, C2-T3 SVA, and C2 slope (P < 0.05). The distribution of over/under corrected patients and the offset between actual and ideal alignment for SVA, PT, TPA, PI-LL, and LL-TK were similar between DJK and non-DJK patients. DJK patients requiring reoperation had worse postoperative changes in all cervical parameters and trended toward larger offsets for global parameters. Conclusion: CD patients with severe baseline malalignment went on to develop postoperative DJK. Age-Adjusted alignment targets did not capture differences in these populations, suggesting the need for cervical-specific goals.Item Open Access Establishment of an Individualized Distal Junctional Kyphosis Risk Index following the Surgical Treatment of Adult Cervical Deformities.(Spine, 2023-01) Passias, Peter G; Naessig, Sara; Sagoo, Navraj; Passfall, Lara; Ahmad, Waleed; Lafage, Renaud; Lafage, Virginie; Vira, Shaleen; Schoenfeld, Andrew J; Oh, Cheongeun; Protopsaltis, Themistocles; Kim, Han Jo; Daniels, Alan; Hart, Robert; Burton, Douglas; Klineberg, Eric O; Bess, Shay; Schwab, Frank; Shaffrey, Christopher; Ames, Christopher P; Smith, Justin S; International Spine Study GroupStudy design
A retrospective review of a multicenter comprehensive cervical deformity (CD) database.Objective
To develop a novel risk index specific to each patient to aid in patient counseling and surgical planning to minimize postop distal junctional kyphosis (DJK) occurrence.Background
DJK is a radiographic finding identified after patients undergo instrumented spinal fusions which can result in sagittal spinal deformity, pain and disability, and potentially neurological compromise. DJK is considered multifactorial in nature and there is a lack of consensus on the true etiology of DJK.Materials and methods
CD patients with baseline (BL) and at least one-year postoperative radiographic follow-up were included. A patient-specific DJK score was created through use of unstandardized Beta weights of a multivariate regression model predicting DJK (end of fusion construct to the second distal vertebra change in this angle by <-10° from BL to postop).Results
A total of 110 CD patients included (61 yr, 66.4% females, 28.8 kg/m 2 ). In all, 31.8% of these patients developed DJK (16.1% three males, 11.4% six males, 62.9% one-year). At BL, DJK patients were more frail and underwent combined approach more (both P <0.05). Multivariate model regression analysis identified individualized scores through creation of a DJK equation: -0.55+0.009 (BL inclination)-0.078 (preinflection)+5.9×10 -5 (BL lowest instrumented vertebra angle) + 0.43 (combine approach)-0.002 (BL TS-CL)-0.002 (BL pelvic tilt)-0.031 (BL C2 - C7) + 0.02 (∆T4-T12)+ 0.63 (osteoporosis)-0.03 (anterior approach)-0.036 (frail)-0.032 (3 column osteotomy). This equation has a 77.8% accuracy of predicting DJK. A score ≥81 predicted DJK with an accuracy of 89.3%. The BL reference equation correlated with two year outcomes of Numeric Rating Scales of Back percentage ( P =0.003), reoperation ( P =0.04), and minimal clinically importance differences for 5-dimension EuroQol questionnaire ( P =0.04).Conclusions
This study proposes a novel risk index of DJK development that focuses on potentially modifiable surgical factors as well as established patient-related and radiographic determinants. The reference model created demonstrated strong correlations with relevant two-year outcome measures, including axial pain-related symptoms, occurrence of related reoperations, and the achievement of minimal clinically importance differences for 5-dimension EuroQol questionnaire.Item Open Access Fatty infiltration of the cervical extensor musculature, cervical sagittal balance, and clinical outcomes: An analysis of operative adult cervical deformity patients.(Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2020-02) Passias, Peter G; Segreto, Frank A; Horn, Samantha R; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Naessig, Sara; Bortz, Cole; Klineberg, Eric O; Diebo, Bassel G; Sciubba, Daniel M; Neuman, Brian J; Hamilton, D Kojo; Burton, Douglas C; Hart, Robert A; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Nunley, Pierce; Ames, Christopher P; International Spine Study GroupPURPOSE:To assess preliminary associations between fatty-infiltration (FI) of cervical spine extensor musculature, cervical sagittal balance, and clinical outcomes in cervical deformity (CD) patients. METHODS:Operative CD patients (C2-C7 Cobb > 10°, CL > 10°, cSVA > 4 cm, or CBVA > 25°) with pre-operative (BL) MRIs and 1-year (1Y) post-operative MRIs or CTs were assessed for fatty-infiltration of cervical extensor musculature, using dedicated imaging software at each C2-C7 intervertebral level and the apex of deformity (apex). FI was gauged as a ratio of fat-free-muscle-cross-sectional-area (FCSA) over total-muscle-CSA (TCSA), with lower ratio values indicating greater FI. BL-1Y associations between FI, sagittal alignment, and clinical outcomes were assessed using appropriate parametric and non-parametric tests. RESULTS:22 patients were included (Age 59.22, 71.4%F, BMI 29.2, CCI:0.75, Frailty: 0.43). BL deformity presentation: TS-CL: 29.0°, C2-C7 Sagittal Cobb:-1.6°, cSVA:30.4 mm. No correlations were observed between BL fatty-infiltration, sagittal alignment, frailty, or clinical outcomes (p > 0.05). Following surgical correction, C2-C7 (BL: 0.59 vs 1Y:0.67, p = 0.005) and apex (BL: 0.59 vs. 1Y: 0.66, p = 0.33) fatty-infiltration decreased. Achievement of lordotic curvature correlated with C2-C7 fatty infiltration reduction (Rs: 0.495, p < 0.05), and patients with residual postoperative TS-CL and cSVA malalignment were associated with greater apex fatty-infiltration (Rs: -0.565, -0.561; p < 0.05). C2-C7 FI improvement was associated with NRS back pain reduction (Rs: -0.630, p < 0.05), and greater apex fatty-infiltration at BL was associated with minor perioperative complication occurrence (Rs: 0.551, p = 0.014). CONCLUSIONS:Deformity correction and sagittal balance appear to influence the reestablishment of cervical muscle tone from C2-C7 and reduction of back pain for severely frail CD patients. This analysis helps to understand cervical extensor musculature's role amongst CD patients.Item Open Access Impact of congestive heart failure on patients undergoing lumbar spine fusion for adult spine deformity.(Journal of craniovertebral junction & spine, 2024-01) Onafowokan, Oluwatobi O; Ahmad, Waleed; McFarland, Kimberly; Williamson, Tyler K; Tretiakov, Peter; Mir, Jamshaid M; Das, Ankita; Bell, Joshua; Naessig, Sara; Vira, Shaleen; Lafage, Virginie; Paulino, Carl; Diebo, Bassel; Schoenfeld, Andrew; Hassanzadeh, Hamid; Jankowski, Pawel P; Hockley, Aaron; Passias, Peter GustBackground
With the increasing amount of elective spine fusion patients presenting with cardiac disease and congestive heart failure, it is becoming difficult to assess when it is safe to proceed with surgery. Assessing the severity of heart failure (HF) through ejection fraction may provide insight into patients' short- and long-term risks.Purpose
The purpose of this study was to assess the severity of HF on perioperative outcomes of spine fusion surgery patients.Study design/setting
This was a retrospective cohort study of the PearlDiver database.Patient sample
We enrolled 670,526 patients undergoing spine fusion surgery.Outcome measures
Thirty-day and 90-day complication rates, discharge destination, length of stay (LOS), physician reimbursement, and hospital costs.Methods
Patients undergoing elective spine fusion surgery were isolated and stratified by preoperative HF with preserved ejection fraction (P-EF) or reduced ejection fraction (R-EF) (International Classification of Diseases-9: 428.32 [chronic diastolic HF] and 428.22 [chronic systolic HF]). Means comparison tests (Chi-squared and independent samples t-tests, as appropriate) compared differences in demographics, diagnoses, comorbidities, procedural characteristics, LOS, 30-day and 90-day complication outcomes, and total hospital charges between those diagnosed with P-EF and those not R-EF. Binary logistic regression assessed the odds of complication associated with HF, controlling for levels fused (odds ratio [OR] [95% confidence interval]). Statistical significance was set at P < 0.05.Results
Totally 670,526 elective spine fusion patients were included. Four thousand and seventy-seven were diagnosed with P-EF and 2758 R-EF. Overall, P-EF patients presented with higher rates of morbid obesity, chronic kidney disease, chronic obstructive pulmonary disease, diabetes mellitus, and hypertension (all P < 0.001). In relation to No-HF, P-EF patients had higher rates of 30-day major complications including pulmonary embolism, pneumonia, cerebrovascular accident (CVA), myocardial infarctions (MI), sepsis, and death (all P < 0.001). Furthermore, P-EF was associated significantly with increased odds of pneumonia (OR: 2.07 [1.64-2.56], P < 0.001) and sepsis (OR: 2.09 [1.62-2.66], P < 0.001). Relative to No-HF, R-EF was associated with significantly higher odds of MI (OR: 3.66 [2.34-5.47]), CVA (OR: 2.70 [1.67-4.15]), and pneumonia (OR: 1.85 [1.40-2.40]) (all P < 0.001) postoperative within 30 days. Adjusting for prior history of MI, CAD, and the presence of a pacemaker R-EF was a significant predictor of an MI 30 days postoperatively (OR: 2.2 [1.14-4.32], P = 0.021). Further adjusting for history of CABG or stent placement, R-EF was associated with higher odds of CVA (OR: 2.11 [1.09-4.19], P = 0.028) and MI (OR: 2.27 [1.20-4.43], P = 0.013).Conclusions
When evaluating the severity of HF before spine surgery, R-EF was associated with a higher risk of major complications, especially the occurrence of a myocardial infarction 30 days postoperatively. During preoperative risk assessment, congestive HF should be considered thoroughly when thinking of postoperative outcomes with emphasis on R-EF.Item Open Access Increasing Cost Efficiency in Adult Spinal Deformity Surgery: Identifying Predictors of Lower Total Costs.(Spine, 2022-01) Passias, Peter G; Brown, Avery E; Bortz, Cole; Alas, Haddy; Pierce, Katherine; Ahmad, Waleed; Naessig, Sara; Lafage, Renaud; Lafage, Virginie; Hassanzadeh, Hamid; Labaran, Lawal A; Ames, Christopher; Burton, Douglas C; Gum, Jeffrey; Hart, Robert; Hostin, Richard; Kebaish, Khaled M; Neuman, Brian J; Bess, Shay; Line, Breton; Shaffrey, Christopher; Smith, Justin; Schwab, Frank; Klineberg, Eric; International Spine Study GroupStudy design
Retrospective study of a prospective multicenter database.Objective
The purpose of this study was to identify predictors of lower total surgery costs at 3 years for adult spinal deformity (ASD) patients.Summary of background data
ASD surgery involves complex deformity correction.Methods
Inclusion criteria: surgical ASD (scoliosis ≥20°, sagittal vertical axis [SVA] ≥5 cm, pelvic tilt ≥25°, or thoracic kyphosis ≥60°) patients >18 years. Total costs for surgery were calculated using the PearlDiver database. Cost per quality-adjusted life year was assessed. A Conditional Variable Importance Table used nonreplacement sampling set of 20,000 Conditional Inference trees to identify top factors associated with lower cost surgery for low (LSVA), moderate (MSVA), and high (HSVA) SRS Schwab SVA grades.Results
Three hundred sixtee of 322 ASD patients met inclusion criteria. At 3-year follow up, the potential cost of ASD surgery ranged from $57,606.88 to $116,312.54. The average costs of surgery at 3 years was found to be $72,947.87, with no significant difference in costs between deformity groups (P > 0.05). There were 152 LSVA patients, 53 MSVA patients, and 111 HSVA patients. For all patients, the top predictors of lower costs were frailty scores <0.19, baseline (BL) SRS Activity >1.5, BL Oswestry Disability Index <50 (all P < 0.05). For LSVA patients, no history of osteoporosis, SRS Activity scores >1.5, age <64, were the top predictors of lower costs (all P < 0.05). Among MSVA patients, ASD invasiveness scores <94.16, no past history of cancer, and frailty scores <0.3 trended toward lower total costs (P = 0.071, P = 0.210). For HSVA, no history of smoking and body mass index <27.8 trended toward lower costs (both P = 0.060).Conclusion
ASD surgery has the potential for improved cost efficiency, as costs ranged from $57,606.88 to $116,312.54. Predictors of lower costs included higher BL SRS activity, decreased frailty, and not having depression. Additionally, predictors of lower costs were identified for different BL deformity profiles, allowing for the optimization of cost efficiency for all patients.Level of Evidence: 3.Item Open Access Patient-related and radiographic predictors of inferior health-related quality-of-life measures in adult patients with nonoperative spinal deformity.(Journal of neurosurgery. Spine, 2021-04) Passias, Peter G; Alas, Haddy; Bess, Shay; Line, Breton G; Lafage, Virginie; Lafage, Renaud; Ames, Christopher P; Burton, Douglas C; Brown, Avery; Bortz, Cole; Pierce, Katherine; Ahmad, Waleed; Naessig, Sara; Kelly, Michael P; Hostin, Richard; Kebaish, Khaled M; Than, Khoi D; Nunley, Pierce; Shaffrey, Christopher I; Klineberg, Eric O; Smith, Justin S; Schwab, Frank J; International Spine Study GroupObjective
Patients with nonoperative (N-Op) adult spinal deformity (ASD) have inferior long-term spinopelvic alignment and clinical outcomes. Predictors of lower quality-of-life measures in N-Op populations have yet to be sufficiently investigated. The aim of this study was to identify patient-related factors and radiographic parameters associated with inferior health-related quality-of-life (HRQOL) scores in N-Op ASD patients.Methods
N-Op ASD patients with complete radiographic and outcome data at baseline and 2 years were included. N-Op patients and operative (Op) patients were propensity score matched for baseline disability and deformity. Patient-related factors and radiographic alignment parameters (pelvic tilt [PT], sagittal vertical axis [SVA], pelvic incidence [PI]-lumbar lordosis [LL] mismatch, mismatch between cervical lordosis and T1 segment slope [TS-CL], cervical-thoracic pelvic angle [PA], and others) at baseline and 2 years were analyzed as predictors for moderate to severe 2-year Oswestry Disability Index (ODI > 20) and failing to meet the minimal clinically importance difference (MCID) for 2-year Scoliosis Research Society Outcomes Questionnaire (SRS) scores (< 0.4 increase from baseline). Conditional inference decision trees identified predictors of each HRQOL measure and established cutoffs at which factors have a global effect. Random forest analysis (RFA) generated 5000 conditional inference trees to compute a variable importance table for top predictors of inferior HRQOL. Statistical significance was set at p < 0.05.Results
Six hundred sixty-two patients with ASD (331 Op patients and 331 N-Op patients) with complete radiographic and HRQOL data at their 2-year follow-up were included. There were no differences in demographics, ODI, and Schwab deformity modifiers between groups at baseline (all p > 0.05). N-Op patients had higher 2-year ODI scores (27.9 vs 20.3, p < 0.001), higher rates of moderate to severe disability (29.3% vs 22.4%, p = 0.05), lower SRS total scores (3.47 vs 3.91, p < 0.001), and higher rates of failure to reach SRS MCID (35.3% vs 15.7%, p < 0.001) than Op patients at 2 years. RFA ranked the top overall predictors for moderate to severe ODI at 2 years for N-Op patients as follows: 1) frailty index > 2.8, 2) BMI > 35 kg/m2, T4PA > 28°, and 4) Charlson Comorbidity Index > 1. Top radiographic predictors were T4PA > 28° and C2-S1 SVA > 93 mm. RFA also ranked the top overall predictors for failure to reach 2-year SRS MCID for N-Op patients, as follows: 1) T12-S1 lordosis > 53°, 2) cervical SVA (cSVA) > 28 mm, 3) C2-S1 angle > 14.5°, 4) TS-CL > 12°, and 5) PT > 23°. The top radiographic predictors were T12-S1 Cobb angle, cSVA, C2-S1 angle, and TS-CL.Conclusions
When controlling for baseline deformity in N-Op versus Op patients, subsequent deterioration in frailty, BMI, and radiographic progression over a 2-year follow-up were found to drive suboptimal patient-reported outcome measures in N-Op cohorts as measured by validated ODI and SRS clinical instruments.Item Open Access Predicting development of severe clinically relevant distal junctional kyphosis following adult cervical deformity surgery, with further distinction from mild asymptomatic episodes.(Journal of neurosurgery. Spine, 2021-12) Passias, Peter G; Naessig, Sara; Kummer, Nicholas; Passfall, Lara; Lafage, Renaud; Lafage, Virginie; Line, Breton; Diebo, Bassel G; Protopsaltis, Themistocles; Kim, Han Jo; Eastlack, Robert; Soroceanu, Alex; Klineberg, Eric O; Hart, Robert A; Burton, Douglas; Bess, Shay; Schwab, Frank; Shaffrey, Christopher I; Smith, Justin S; Ames, Christopher POBJECTIVE:This retrospective cohort study aimed to develop a formal predictive model distinguishing between symptomatic and asymptomatic distal junctional kyphosis (DJK). In this study the authors identified a DJK rate of 32.2%. Predictive models were created that can be used with high reliability to help distinguish between severe symptomatic DJK and mild asymptomatic DJK through the use of surgical factors, radiographic parameters, and patient variables. METHODS:Patients with cervical deformity (CD) were stratified into asymptomatic and symptomatic DJK groups. Symptomatic: 1) DJK angle (DJKA) > 10° and either reoperation due to DJK or > 1 new-onset neurological sequela related to DJK; or 2) either a DJKA > 20° or ∆DJKA > 20°. Asymptomatic: ∆DJK > 10° in the absence of neurological sequelae. Stepwise logistic regressions were used to identify factors associated with these types of DJK. Decision tree analysis established cutoffs. RESULTS:A total of 99 patients with CD were included, with 32.2% developing DJK (34.3% asymptomatic, 65.7% symptomatic). A total of 37.5% of asymptomatic patients received a reoperation versus 62.5% symptomatic patients. Multivariate analysis identified independent baseline factors for developing symptomatic DJK as follows: pelvic incidence (OR 1.02); preoperative cervical flexibility (OR 1.04); and combined approach (OR 6.2). Having abnormal hyperkyphosis in the thoracic spine, more so than abnormal cervical lordosis, was a factor for developing symptomatic disease when analyzed against asymptomatic patients (OR 1.2). Predictive modeling identified factors that were predictive of symptomatic versus no DJK, as follows: myelopathy (modified Japanese Orthopaedic Association score 12-14); combined approach; uppermost instrumented vertebra C3 or C4; preoperative hypermobility; and > 7 levels fused (area under the curve 0.89). A predictive model for symptomatic versus asymptomatic disease (area under the curve 0.85) included being frail, T1 slope minus cervical lordosis > 20°, and a pelvic incidence > 46.3°. Controlling for baseline deformity and disability, symptomatic patients had a greater cervical sagittal vertical axis (4-8 cm: 47.6% vs 27%) and were more malaligned according to their Scoliosis Research Society sagittal vertical axis measurement (OR 0.1) than patients without DJK at 1 year (all p < 0.05). Despite their symptomatology and higher reoperation rate, outcomes equilibrated in the symptomatic cohort at 1 year following revision. CONCLUSIONS:Overall, 32.2% of patients with CD suffered from DJK. Symptomatic DJK can be predicted with high reliability. It can be further distinguished from asymptomatic occurrences by taking into account pelvic incidence and baseline cervicothoracic deformity severity.Item Open Access Predictors of reoperation for spinal disorders in Chiari malformation patients with prior surgical decompression.(Journal of craniovertebral junction & spine, 2023-10) Onafowokan, Oluwatobi O; Das, Ankita; Mir, Jamshaid M; Alas, Haddy; Williamson, Tyler K; Mcfarland, Kimberly; Varghese, Jeffrey; Naessig, Sara; Imbo, Bailey; Passfall, Lara; Krol, Oscar; Tretiakov, Peter; Joujon-Roche, Rachel; Dave, Pooja; Moattari, Kevin; Owusu-Sarpong, Stephane; Lebovic, Jordan; Vira, Shaleen; Diebo, Bassel; Lafage, Virginie; Passias, Peter GustBackground
Chiari malformation (CM) is a cluster of related developmental anomalies of the posterior fossa ranging from asymptomatic to fatal. Cranial and spinal decompression can help alleviate symptoms of increased cerebrospinal fluid pressure and correct spinal deformity. As surgical intervention for CM increases in frequency, understanding predictors of reoperation may help optimize neurosurgical planning.Materials and methods
This was a retrospective analysis of the prospectively collected Healthcare Cost and Utilization Project's California State Inpatient Database years 2004-2011. Chiari malformation Types 1-4 (queried with ICD-9 CM codes) with associated spinal pathologies undergoing stand-alone spinal decompression (queried with ICD-9 CM procedure codes) were included. Cranial decompressions were excluded.Results
One thousand four hundred and forty-six patients (29.28 years, 55.6% of females) were included. Fifty-eight patients (4.01%) required reoperation (67 reoperations). Patients aged 40-50 years had the most reoperations (11); however, patients aged 15-20 years had a significantly higher reoperation rate than all other groups (15.5% vs. 8.2%, P = 0.048). Female gender was significantly associated with reoperation (67.2% vs. 55.6%, P = 0.006). Medical comorbidities associated with reoperation included chronic lung disease (19% vs. 6.9%, P < 0.001), iron deficiency anemia (10.3% vs. 4.1%, P = 0.024), and renal failure (3.4% vs. 0.9%, P = 0.05). Associated significant cluster anomalies included spina bifida (48.3% vs. 34.8%, P = 0.035), tethered cord syndrome (6.9% vs. 2.1%, P = 0.015), syringomyelia (12.1% vs. 5.9%, P = 0.054), hydrocephalus (37.9% vs. 17.7%, P < 0.001), scoliosis (13.8% vs. 6.4%, P = 0.028), and ventricular septal defect (6.9% vs. 2.3%, P = 0.026).Conclusions
Multiple medical and CM-specific comorbidities were associated with reoperation. Addressing them, where possible, may aid in improving CM surgery outcomes.Item Open Access Probability of severe frailty development among operative and nonoperative adult spinal deformity patients: an actuarial survivorship analysis over a 3-year period.(The spine journal : official journal of the North American Spine Society, 2020-08) Passias, Peter G; Segreto, Frank A; Bortz, Cole A; Horn, Samantha R; Pierce, Katherine E; Naessig, Sara; Brown, Avery E; Jackson-Fowl, Brendan; Ahmad, Waleed; Oh, Cheongeun; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Daniels, Alan H; Line, Breton G; Kim, Han Jo; Uribe, Juan S; Eastlack, Robert K; Hamilton, D Kojo; Klineberg, Eric O; Burton, Douglas C; Hart, Robert AA; Schwab, Frank J; Shaffrey, Christopher I; Ames, Christopher P; Bess, Shay; International Spine Study GroupBackground
Little is known of how frailty, a dynamic measure of physiological age, progresses relative to age or disability status. Operative treatment of adult spinal deformity (ASD) may play a role in frailty remediation and maintenance.Purpose
Compare frailty status, severe frailty development, and factors influencing severe frailty development among ASD patients undergoing operative or nonoperative treatment.Design
Retrospective review with maximum follow-up of 3 years.Setting
Prospective, multicenter, ASD database.Participants
Patients were consecutively enrolled from 13 participating centers.Inclusion criteria
≥18 years undergoing either operative or nonoperative treatment for ASD, exclusion criteria: spinal deformity of neuromuscular etiology, presence of active infection, or malignancy. The mean age of the participants analyzed were 54.9 for the operative cohort and 55.0 for the nonoperative cohort.Outcomes measures
Frailty status, severe frailty development, and factors influencing severe frailty development.Methods
ASD patients (coronal scoliosis ≥20°, sagittal vertical axis (SVA) ≥5 cm, Pelvic Tilt (PT) ≥25°, or thoracic kyphosis ≥60°) >18 y/o, with Base Line (BL) frailty scores were included. Frailty was scored from 0 to 1 (not frail: <0.3, frail 0.3-0.5, severe frailty >0.5) through the use of ASD-frailty index (FI) which has been validated using the International Spine Study Group (ISSG) ASD database, European Spine Study Group ASD database, and the Scoli-RISK-1 Patient Database. The ISSG is funded through research grants from DePuy Synthes and individual donations and supported the current work. Operative (Op) and Nonoperative (Non-Op) patients were propensity matched. T-tests compared frailty among treatment groups and BL, 1, 2, and ≥3 years. An actuarial Kaplan-Meier survivorship analysis with log-rank (Mantel-Cox) test, adjusting for patients lost to follow-up, determined probability of severe frailty development. Multivariate Cox Regressions gauged the effect of sagittal malalignment, patient and surgical details on severe frailty development.Results
The analysis includes 472 patients (236 Op, 236 Non-Op) selected by propensity score matching from a cohort of 1,172. Demographics and comorbidities were similar between groups (p>.05). Op exhibited decreased frailty at all follow-up intervals compared with BL (BL: 0.22 vs Y1: 0.18; Y2: 0.16; Y3: 0.15, all p<.001). Non-Op displayed similar frailty from BL to 2Y follow up, and increased frailty at 3Y follow up (0.23 vs 0.25, p=.014). Compared with Non-Op, Op had lower frailty at 1Y (0.18 vs 0.24), 2Y (0.16 vs 0.23), and 3Y (0.15 vs 0.25; all p<.001). Cumulative probability of maintaining nonsevere frailty was (Op: 97.7%, Non-Op: 94.5%) at 1Y, (Op: 95.1%, Non-Op: 90.4%) at 2Y, and (Op: 95.1%, Non-Op: 89.1%) at ≥3Y, (p=.018). Among all patients, baseline depression (hazard ratio: 2.688[1.172-6.167], p=.020), Numeric Rating Scale (NRS) back pain scores (HR: 1.247[1.012-1.537], p=.039), and nonoperative treatment (HR: 2.785[1.167-6.659], p=.021) predicted severe frailty development with having a HR>1.0 and p value<.05. Among operative patients, 6-week postoperative residual SVA malalignment (SRS-Schwab SVA+modifier) (HR: 15.034[1.922-116.940], p=.010) predicted severe frailty development indicated by having a HR>1.0 and p value <.05.Conclusions
Non-Op patients were more likely to develop severe frailty, and at a quicker rate. Baseline depression, increased NRS back pain scores, nonoperative treatment, and postoperative sagittal malalignment at 6-week follow-up significantly predicted severe frailty development. Operative intervention and postoperative sagittal balance appear to play significant roles in frailty remediation and maintenance in ASD patients. Frailty is one factor, in a multifactorial conservation, that may be considered when determining operative or nonoperative values for ASD patients. Operating before the onset of severe frailty, may result in a lower complication risk and better long-term clinical outcomes.Item Open Access Radiographic benefit of incorporating the inflection between the cervical and thoracic curves in fusion constructs for surgical cervical deformity patients(Journal of Craniovertebral Junction and Spine, 2020-04-01) Bortz, Cole; Passias, Peter G; Pierce, Katherine Elizabeth; Alas, Haddy; Brown, Avery; Naessig, Sara; Ahmad, Waleed; Lafage, Renaud; Ames, Christopher P; Diebo, Bassel G; Line, Breton G; Klineberg, Eric O; Burton, Douglas C; Eastlack, Robert K; Kim, Han Jo; Sciubba, Daniel M; Soroceanu, Alex; Bess, Shay; Shaffrey, Christopher I; Schwab, Frank J; Smith, Justin S; Lafage, Virginie; International Spine Study GroupPurpose: The aim is to assess the relationship between cervicothoracic inflection point and baseline disability, as well as the relationship between clinical outcomes and pre- to postoperative changes in inflection point. Methods: Cervical deformity (CD) patients with baseline and 3-month (3M) postoperative radiographic, clinical, and inflection data were grouped by region of inflection point: C6 or above, C6-C7 to C7-T1, T1, or below. Inflection was defined as: Distal-most level where cervical lordosis (CL) changes to thoracic kyphosis (TK). Differences in alignment and patient factors across pre- and postoperative inflection point groups were assessed, as were outcomes by the inclusion of inflection in the CD-corrective fusion construct. Results: A total of 108 patients were included. Preoperative inflection breakdown: C6 or above (42%), C6-C7 to C7-T1 (44%), T1 or below (15%). Surgery was associated with a caudal migration of inflection by 3M: C6 or above (8%), C6-C7 to C7-T1 (58%), T1 or below (33%). For patients with preoperative inflection T1 or below, the inclusion of inflection in the fusion construct was associated with improvements in horizontal gaze (McGregor's Slope included: -11.3° vs. not included: 1.6°, P = 0.038). The inclusion of preoperative inflection in fusion was associated with the superior cervical sagittal vertical axis (cSVA) changes for C6-C7 to C7-T1 patients (-5.2 mm vs. 3.2 mm, P = 0.018). The location of postoperative inflection was associated with variation in 3M alignment: Inflection C6 or above was associated with less Pelvic Tilt (PT), PT and a trend of larger cSVA. Location of inflection or inclusion in fusion was not associated with reoperation or distal junctional kyphosis. Conclusions: Incorporating the inflection point between CL and TK in the fusion construct was associated with superior restoration of cervical alignment and horizontal gaze for surgical CD patients.Item Open Access Timing of conversion to cervical malalignment and proximal junctional kyphosis following surgical correction of adult spinal deformity: a 3-year radiographic analysis.(Journal of neurosurgery. Spine, 2021-03) Passias, Peter G; Alas, Haddy; Naessig, Sara; Kim, Han Jo; Lafage, Renaud; Ames, Christopher; Klineberg, Eric; Pierce, Katherine; Ahmad, Waleed; Burton, Douglas; Diebo, Bassel; Bess, Shay; Hamilton, D Kojo; Gupta, Munish; Park, Paul; Line, Breton; Shaffrey, Christopher I; Smith, Justin S; Schwab, Frank; Lafage, Virginie; International Spine Study GroupObjective
The goal of this study was to assess the conversion rate from baseline cervical alignment to postoperative cervical deformity (CD) and the corresponding proximal junctional kyphosis (PJK) rate in patients undergoing thoracolumbar adult spinal deformity (ASD) surgery.Methods
The operative records of patients with ASD with complete radiographic data beginning at baseline up to 3 years were included. Patients with no baseline CD were postoperatively stratified by Ames CD criteria (T1 slope-cervical lordosis mismatch [TS-CL] > 20°, cervical sagittal vertical axis [cSVA] > 40 mm), where CD was defined as fulfilling one or more of the Ames criteria. Severe CD was defined as TS-CL > 30° or cSVA > 60 mm. Follow-up intervals were established after ASD surgery, with 6 weeks postoperatively defined as early; 6 weeks-1 year as intermediate; 1-2 years as late; and 2-3 years as long-term. Descriptive analyses and McNemar tests identified the CD conversion rate, PJK rate (< -10° change in uppermost instrumented vertebra and the superior endplate of the vertebra 2 levels superior to the uppermost instrumented vertebra), and specific alignment parameters that converted.Results
Two hundred sixty-six patients who underwent ASD surgery (mean age 59.7 years, 77.4% female) met the inclusion criteria; 103 of these converted postoperatively, and the remaining 163 did not meet conversion criteria. Thirty-eight patients converted to CD early, 26 converted at the intermediate time point, 29 converted late, and 10 converted in the long-term. At conversion, the early group had the highest mean TS-CL at 25.4° ± 8.5° and the highest mean cSVA at 33.6 mm-both higher than any other conversion group. The long-term group had the highest mean C2-7 angle at 19.7° and the highest rate of PJK compared to other groups (p = 0.180). The early group had the highest rate of conversion to severe CD, with 9 of 38 patients having severe TS-CL and only 1 patient per group converting to severe cSVA. Seven patients progressed from having only malaligned TS-CL at baseline (with normal cSVA) to CD with both malaligned TS-CL and cSVA by 6 weeks. Conversely, only 2 patients progressed from malaligned cSVA to both malaligned cSVA and TS-CL. By 1 year, the former number increased from 7 to 26 patients, and the latter increased from 2 to 20 patients. The revision rate was highest in the intermediate group at 48.0%, versus the early group at 19.2%, late group at 27.3%, and long-term group at 20% (p = 0.128). A higher pelvic incidence-lumbar lordosis mismatch, lower thoracic kyphosis, and a higher thoracic kyphosis apex immediately postoperatively significantly predicted earlier rather than later conversion (all p < 0.05). Baseline lumbar lordosis, pelvic tilt, and sacral slope were not significant predictors.Conclusions
Patients with ASD with normative cervical alignment who converted to CD after thoracolumbar surgery had varying radiographic findings based on timing of conversion. Although the highest number of patients converted within 6 weeks postoperatively, patients who converted in the late or long-term follow-up intervals had higher rates of concurrent PJK and greater radiographic progression.Item Open Access Trends in usage of navigation and robotic assistance in elective spine surgeries: a study of 105,212 cases from 2007 to 2015.(Journal of robotic surgery, 2023-12) Naessig, Sara; Para, Ashok; Kummer, Nicholas; Krol, Oscar; Passfall, Lara; Ahmad, Waleed; Pierce, Katherine; Vira, Shaleen; Diebo, Bassel; Neuman, Brian; Jain, Amit; Sciubba, Daniel; Passias, PeterObjective
Identify trends of navigation and robotic-assisted elective spine surgeries.Methods
Elective spine surgery patients between 2007 and 2015 in the Nationwide Inpatient Sample (NIS) were isolated by ICD-9 codes for Navigation [Nav] or Robotic [Rob]-Assisted surgery. Basic demographics and surgical variables were identified via chi-squared and t tests. Each system was analyzed from 2007 to 2015 for trends in usage.Results
Included 3,759,751 patients: 100,488 Nav; 4724 Rob. Nav were younger (56.7 vs 62.7 years), had lower comorbidity index (1.8 vs 6.2, all p < 0.05), more decompressions (79.5 vs 42.6%) and more fusions (60.3 vs 52.6%) than Rob. From 2007 to 2015, incidence of complication increased for Nav (from 5.8 to 21.7%) and Rob (from 3.3 to 18.4%) as well as 2-3 level fusions (from 50.4 to 52.5%) and (from 1.3 to 3.2%); respectively. Invasiveness increased for both (Rob: from 1.7 to 2.2; Nav: from 3.7 to 4.6). Posterior approaches (from 27.4 to 41.3%), osteotomies (from 4 to 7%), and fusions (from 40.9 to 54.2%) increased in Rob. Anterior approach for Rob decreased from 14.9 to 14.4%. Nav increased posterior (from 51.5% to 63.9%) and anterior approaches (from 16.4 to 19.2%) with an increase in osteotomies (from 2.1 to 2.7%) and decreased decompressions (from 73.6 to 63.2%).Conclusions
From 2007 to 2015, robotic and navigation systems have been performed on increasingly invasive spine procedures. Robotic systems have shifted from anterior to posterior approaches, whereas navigation computer-assisted procedures have decreased in rates of usage for decompression procedures.