Browsing by Author "Nunley, Pierce D"
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Item Open Access Calibration of a comprehensive predictive model for the development of proximal junctional kyphosis and failure in adult spinal deformity patients with consideration of contemporary goals and techniques.(Journal of neurosurgery. Spine, 2023-06) Tretiakov, Peter S; Lafage, Renaud; Smith, Justin S; Line, Breton G; Diebo, Bassel G; Daniels, Alan H; Gum, Jeffrey; Protopsaltis, Themistocles; Hamilton, D Kojo; Soroceanu, Alex; Scheer, Justin K; Eastlack, Robert K; Mundis, Gregory; Nunley, Pierce D; Klineberg, Eric O; Kebaish, Khaled; Lewis, Stephen; Lenke, Lawrence; Hostin, Richard; Gupta, Munish C; Ames, Christopher P; Hart, Robert A; Burton, Douglas; Shaffrey, Christopher I; Schwab, Frank; Bess, Shay; Kim, Han Jo; Lafage, Virginie; Passias, Peter GObjective
The objective of this study was to calibrate an updated predictive model incorporating novel clinical, radiographic, and prophylactic measures to assess the risk of proximal junctional kyphosis (PJK) and failure (PJF).Methods
Operative patients with adult spinal deformity (ASD) and baseline and 2-year postoperative data were included. PJK was defined as ≥ 10° in sagittal Cobb angle between the inferior uppermost instrumented vertebra (UIV) endplate and superior endplate of the UIV + 2 vertebrae. PJF was radiographically defined as a proximal junctional sagittal Cobb angle ≥ 15° with the presence of structural failure and/or mechanical instability, or PJK with reoperation. Backstep conditional binary supervised learning models assessed baseline demographic, clinical, and surgical information to predict the occurrence of PJK and PJF. Internal cross validation of the model was performed via a 70%/30% cohort split. Conditional inference tree analysis determined thresholds at an alpha level of 0.05.Results
Seven hundred seventy-nine patients with ASD (mean 59.87 ± 14.24 years, 78% female, mean BMI 27.78 ± 6.02 kg/m2, mean Charlson Comorbidity Index 1.74 ± 1.71) were included. PJK developed in 50.2% of patients, and 10.5% developed PJF by their last recorded visit. The six most significant demographic, radiographic, surgical, and postoperative predictors of PJK/PJF were baseline age ≥ 74 years, baseline sagittal age-adjusted score (SAAS) T1 pelvic angle modifier > 1, baseline SAAS pelvic tilt modifier > 0, levels fused > 10, nonuse of prophylaxis measures, and 6-week SAAS pelvic incidence minus lumbar lordosis modifier > 1 (all p < 0.015). Overall, the model was deemed significant (p < 0.001), and internally validated receiver operating characteristic analysis returned an area under the curve of 0.923, indicating robust model fit.Conclusions
PJK and PJF remain critical concerns in ASD surgery, and efforts to reduce the occurrence of PJK and PJF have resulted in the development of novel prophylactic techniques and enhanced clinical and radiographic selection criteria. This study demonstrates a validated model incorporating such techniques that may allow for the prediction of clinically significant PJK and PJF, and thus assist in optimizing patient selection, enhancing intraoperative decision making, and reducing postoperative complications in ASD surgery.Item Open Access Can a Minimal Clinically Important Difference Be Achieved in Elderly Patients with Adult Spinal Deformity Who Undergo Minimally Invasive Spinal Surgery?(World neurosurgery, 2016-02) Park, Paul; Okonkwo, David O; Nguyen, Stacie; Mundis, Gregory M; Than, Khoi D; Deviren, Vedat; La Marca, Frank; Fu, Kai-Ming; Wang, Michael Y; Uribe, Juan S; Anand, Neel; Fessler, Richard; Nunley, Pierce D; Chou, Dean; Kanter, Adam S; Shaffrey, Christopher I; Akbarnia, Behrooz A; Passias, Peter G; Eastlack, Robert K; Mummaneni, Praveen V; International Spine Study GroupBackground
Older age has been considered a relative contraindication to complex spinal procedures. Minimally invasive surgery (MIS) techniques to treat patients with adult spinal deformity (ASD) have emerged with the potential benefit of decreased approach-related morbidity.Objective
To determine whether a minimal clinically important difference (MCID) could be achieved in patients ages ≥ 65 years with ASD who underwent MIS.Methods
Multicenter database of patients who underwent MIS for ASD was queried. Outcome metrics assessed were Oswestry Disability Index (ODI) and visual analog scale (VAS) scores for back and leg pain. On the basis of published reports, MCID was defined as a positive change of 12.8 ODI, 1.2 VAS back pain, and 1.6 VAS leg pain.Results
Forty-two patients were identified. Mean age was 70.3 years; 31 (73.8%) were women. Preoperatively, mean coronal curve, pelvic tilt, pelvic incidence to lumbar lordosis mismatch, and sagittal vertical axis were 35°, 24.6°, 14.2°, and 4.7 cm, respectively. Postoperatively, mean coronal curve, pelvic tilt, pelvic incidence to lumbar lordosis, and sagittal vertical axis were 18°, 25.4°, 11.9°, and 4.9 cm, respectively. A mean of 5.0 levels was treated posteriorly, and a mean of 4.0 interbody fusions was performed. Mean ODI improved from 47.1 to 25.1. Mean VAS back and leg pain scores improved from 6.8 and 5.9 to 2.7 and 2.7, respectively. Mean follow-up was 32.1 months. For ODI, 64.3% of patients achieved MCID. For VAS back and leg pain, 82.9% and 72.2%, respectively, reached MCID.Conclusions
MCID represents the threshold at which patients feel a meaningful clinical improvement has occurred. Our study results suggest that the majority of elderly patients with modest ASD can achieve MCID with MIS.Item Open Access Clinical and radiographic parameters associated with best versus worst clinical outcomes in minimally invasive spinal deformity surgery.(Journal of neurosurgery. Spine, 2016-07) Than, Khoi D; Park, Paul; Fu, Kai-Ming; Nguyen, Stacie; Wang, Michael Y; Chou, Dean; Nunley, Pierce D; Anand, Neel; Fessler, Richard G; Shaffrey, Christopher I; Bess, Shay; Akbarnia, Behrooz A; Deviren, Vedat; Uribe, Juan S; La Marca, Frank; Kanter, Adam S; Okonkwo, David O; Mundis, Gregory M; Mummaneni, Praveen V; International Spine Study GroupOBJECTIVE Minimally invasive surgery (MIS) techniques are increasingly used to treat adult spinal deformity. However, standard minimally invasive spinal deformity techniques have a more limited ability to restore sagittal balance and match the pelvic incidence-lumbar lordosis (PI-LL) than traditional open surgery. This study sought to compare "best" versus "worst" outcomes of MIS to identify variables that may predispose patients to postoperative success. METHODS A retrospective review of minimally invasive spinal deformity surgery cases was performed to identify parameters in the 20% of patients who had the greatest improvement in Oswestry Disability Index (ODI) scores versus those in the 20% of patients who had the least improvement in ODI scores at 2 years' follow-up. RESULTS One hundred four patients met the inclusion criteria, and the top 20% of patients in terms of ODI improvement at 2 years (best group, 22 patients) were compared with the bottom 20% (worst group, 21 patients). There were no statistically significant differences in age, body mass index, pre- and postoperative Cobb angles, pelvic tilt, pelvic incidence, levels fused, operating room time, and blood loss between the best and worst groups. However, the mean preoperative ODI score was significantly higher (worse disability) at baseline in the group that had the greatest improvement in ODI score (58.2 vs 39.7, p < 0.001). There was no difference in preoperative PI-LL mismatch (12.8° best vs 19.5° worst, p = 0.298). The best group had significantly less postoperative sagittal vertical axis (SVA; 3.4 vs 6.9 cm, p = 0.043) and postoperative PI-LL mismatch (10.4° vs 19.4°, p = 0.027) than the worst group. The best group also had better postoperative visual analog scale back and leg pain scores (p = 0.001 and p = 0.046, respectively). CONCLUSIONS The authors recommend that spinal deformity surgeons using MIS techniques focus on correcting a patient's PI-LL mismatch to within 10° and restoring SVA to < 5 cm. Restoration of these parameters seems to impact which patients will attain the greatest degree of improvement in ODI outcomes, while the spines of patients who do the worst are not appropriately corrected and may be fused into a fixed sagittal plane deformity.Item Open Access Comparison of Complications and Clinical and Radiographic Outcomes Between Nonobese and Obese Patients with Adult Spinal Deformity Undergoing Minimally Invasive Surgery.(World neurosurgery, 2016-03) Park, Paul; Wang, Michael Y; Nguyen, Stacie; Mundis, Gregory M; La Marca, Frank; Uribe, Juan S; Anand, Neel; Okonkwo, David O; Kanter, Adam S; Fessler, Richard; Eastlack, Robert K; Chou, Dean; Deviren, Vedat; Nunley, Pierce D; Shaffrey, Christopher I; Mummaneni, Praveen V; International Spine Study GroupObjective
Obesity can be associated with increased complications and potentially worse outcomes. We aimed to evaluate the impact of obesity on complications and outcomes in patients with adult spinal deformity (ASD) who underwent minimally invasive surgery (MIS).Methods
A multicenter database of patients with ASD treated via MIS was queried. Of 190 patients in the database, 77 fit the inclusion criteria of 3 or more spinal levels treated minimally invasively. Patients were divided by body mass index (BMI) <30 (nonobese; n = 59) and BMI ≥ 30 (obese; n = 18).Results
Mean BMI was 24.6 nonobese and 35.0 obese (P < 0.001). There were mean 3.8 interbody fusions nonobese and 4.7 obese (P = 0.065). Levels treated posteriorly averaged 5.8 nonobese and 5.9 obese (P = 0.502). Mean follow-up was 34.4 months nonobese and 35.3 months obese (P = 0.976). Baseline radiographic parameters were similar between groups. Postoperatively, SVA averaged 83.9 mm obese and 20.4 mm nonobese (P = 0.002). Postoperative lumbar lordosis-pelvic incidence mismatch averaged 17.9° obese and 9.9° nonobese (P = 0.028). Both groups had improvement in Oswestry Disability Index (ODI) scores with no difference in postoperative ODI scores between groups (P = 0.090). Similarly, both groups had decreased VAS scores for back and leg pain with no difference between groups postoperatively. Twenty (33.9%) nonobese patients versus 7 (38.9%) obese patients had complications (P = 0.452).Conclusions
Our results suggest that obesity does not negatively impact complication rate or clinical outcomes in patients with ASD treated via MIS approaches.Item Open Access Defining modern iatrogenic flatback syndrome: examination of segmental lordosis in short lumbar fusion patients undergoing thoracolumbar deformity correction(European Spine Journal, 2024-01-01) Diebo, Bassel G; Singh, Manjot; Balmaceno-Criss, Mariah; Daher, Mohammad; Lenke, Lawrence G; Ames, Christopher P; Burton, Douglas C; Lewis, Stephen M; Klineberg, Eric O; Lafage, Renaud; Eastlack, Robert K; Gupta, Munish C; Mundis, Gregory M; Gum, Jeffrey L; Hamilton, Kojo D; Hostin, Richard; Passias, Peter G; Protopsaltis, Themistocles S; Kebaish, Khaled M; Kim, Han Jo; Shaffrey, Christopher I; Line, Breton G; Mummaneni, Praveen V; Nunley, Pierce D; Smith, Justin S; Turner, Jay; Schwab, Frank J; Uribe, Juan S; Bess, Shay; Lafage, Virginie; Daniels, Alan H; International Spine Study Group (ISSG)Purpose: Understanding the mechanism and extent of preoperative deformity in revision procedures may provide data to prevent future failures in lumbar spinal fusion patients. Methods: ASD patients without prior spine surgery (PRIMARY) and with prior short (SHORT) and long (LONG) fusions were included. SHORT patients were stratified into modes of failure: implant, junctional, malalignment, and neurologic. Baseline demographics, spinopelvic alignment, offset from alignment targets, and patient-reported outcome measures (PROMs) were compared across PRIMARY and SHORT cohorts. Segmental lordosis analyses, assessing under-, match, or over-correction to segmental and global lordosis targets, were performed by SRS-Schwab coronal curve type and construct length. Results: Among 785 patients, 430 (55%) were PRIMARY and 355 (45%) were revisions. Revision procedures included 181 (23%) LONG and 174 (22%) SHORT corrections. SHORT modes of failure included 27% implant, 40% junctional, 73% malalignment, and/or 28% neurologic. SHORT patients were older, frailer, and had worse baseline deformity (PT, PI-LL, SVA) and PROMs (NRS, ODI, VR-12, SRS-22) compared to primary patients (p < 0.001). Segmental lordosis analysis identified 93%, 88%, and 62% undercorrected patients at LL, L1-L4, and L4-S1, respectively. SHORT patients more often underwent 3-column osteotomies (30% vs. 12%, p < 0.001) and had higher ISSG Surgical Invasiveness Score (87.8 vs. 78.3, p = 0.006). Conclusions: Nearly half of adult spinal deformity surgeries were revision fusions. Revision short fusions were associated with sagittal malalignment, often due to undercorrection of segmental lordosis goals, and frequently required more invasive procedures. Further initiatives to optimize alignment in lumbar fusions are needed to avoid costly and invasive deformity corrections. Level of evidence: IV: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.Item Open Access Factors affecting approach selection for minimally invasive versus open surgery in the treatment of adult spinal deformity: analysis of a prospective, nonrandomized multicenter study.(Journal of neurosurgery. Spine, 2020-06) Park, Paul; Than, Khoi D; Mummaneni, Praveen V; Nunley, Pierce D; Eastlack, Robert K; Uribe, Juan S; Wang, Michael Y; Le, Vivian; Fessler, Richard G; Okonkwo, David O; Kanter, Adam S; Anand, Neel; Chou, Dean; Fu, Kai-Ming G; Haddad, Alexander F; Shaffrey, Christopher I; Mundis, Gregory M; International Spine Study GroupObjective
Surgical decision-making and planning is a key factor in optimizing outcomes in adult spinal deformity (ASD). Minimally invasive spinal (MIS) strategies for ASD have been increasingly used as an option to decrease postoperative morbidity. This study analyzes factors involved in the selection of either a traditional open approach or a minimally invasive approach to treat ASD in a prospective, nonrandomized multicenter trial. All centers had at least 5 years of experience in minimally invasive techniques for ASD.Methods
The study enrolled 268 patients, of whom 120 underwent open surgery and 148 underwent MIS surgery. Inclusion criteria included age ≥ 18 years, and at least one of the following criteria: coronal curve (CC) ≥ 20°, sagittal vertical axis (SVA) > 5 cm, pelvic tilt (PT) > 25°, or thoracic kyphosis (TK) > 60°. Surgical approach selection was made at the discretion of the operating surgeon. Preoperative significant differences were included in a multivariate logistic regression analysis to determine odds ratios (ORs) for approach selection.Results
Significant preoperative differences (p < 0.05) between open and MIS groups were noted for age (61.9 vs 66.7 years), numerical rating scale (NRS) back pain score (7.8 vs 7), CC (36° vs 26.1°), PT (26.4° vs 23°), T1 pelvic angle (TPA; 25.8° vs 21.7°), and pelvic incidence-lumbar lordosis (PI-LL; 19.6° vs 14.9°). No significant differences in BMI (29 vs 28.5 kg/m2), NRS leg pain score (5.2 vs 5.7), Oswestry Disability Index (48.4 vs 47.2), Scoliosis Research Society 22-item questionnaire score (2.7 vs 2.8), PI (58.3° vs 57.1°), LL (38.9° vs 42.3°), or SVA (73.8 mm vs 60.3 mm) were found. Multivariate analysis found that age (OR 1.05, p = 0.002), VAS back pain score (OR 1.21, p = 0.016), CC (OR 1.03, p < 0.001), decompression (OR 4.35, p < 0.001), and TPA (OR 1.09, p = 0.023) were significant factors in approach selection.Conclusions
Increasing age was the primary driver for selecting MIS surgery. Conversely, increasingly severe deformities and the need for open decompression were the main factors influencing the selection of traditional open surgery. As experience with MIS surgery continues to accumulate, future longitudinal evaluation will reveal if more experience, use of specialized treatment algorithms, refinement of techniques, and technology will expand surgeon adoption of MIS techniques for adult spinal deformity.Item Open Access Five-year durability of stand-alone interspinous process decompression for lumbar spinal stenosis(Clinical Interventions in Aging) Nunley, Pierce D; Patel, Vikas V; Orndorff, Douglas G; Lavelle, William F; Block, Jon E; Geisler, Fred HItem Open Access Height Gain Following Correction of Adult Spinal Deformity.(The Journal of bone and joint surgery. American volume, 2023-07) Diebo, Bassel G; Tataryn, Zachary; Alsoof, Daniel; Lafage, Renaud; Hart, Robert A; Passias, Peter G; Ames, Christopher P; Scheer, Justin K; Scheer, Justin K; Lewis, Stephen J; Shaffrey, Christopher I; Burton, Douglas C; Deviren, Vedat; Line, Breton G; Soroceanu, Alex; Hamilton, D Kojo; Klineberg, Eric O; Mundis, Gregory M; Kim, Han Jo; Gum, Jeffrey L; Smith, Justin S; Uribe, Juan S; Kelly, Michael P; Kebaish, Khaled M; Gupta, Munish C; Nunley, Pierce D; Eastlack, Robert K; Hostin, Richard; Protopsaltis, Themistocles S; Lenke, Lawrence G; Schwab, Frank J; Bess, Shay; Lafage, Virginie; Daniels, Alan H; the International Spine Study GroupBackground
Height gain following a surgical procedure for patients with adult spinal deformity (ASD) is incompletely understood, and it is unknown if height gain correlates with patient-reported outcome measures (PROMs).Methods
This was a retrospective cohort study of patients undergoing ASD surgery. Patients with baseline, 6-week, and subanalysis of 1-year postoperative full-body radiographic and PROM data were examined. Correlation analysis examined relationships between vertical height differences and PROMs. Regression analysis was utilized to preoperatively estimate T1-S1 and S1-ankle height changes.Results
This study included 198 patients (mean age, 57 years; 69% female); 147 patients (74%) gained height. Patients with height loss, compared with those who gained height, experienced greater increases in thoracolumbar kyphosis (2.81° compared with -7.37°; p < 0.001) and thoracic kyphosis (12.96° compared with 4.42°; p = 0.003). For patients with height gain, sagittal and coronal alignment improved from baseline to postoperatively: 25° to 21° for pelvic tilt (PT), 14° to 3° for pelvic incidence - lumbar lordosis (PI-LL), and 60 mm to 17 mm for sagittal vertical axis (SVA) (all p < 0.001). The full-body mean height gain was 7.6 cm, distributed as follows: sella turcica-C2, 2.9 mm; C2-T1, 2.8 mm; T1-S1 (trunk gain), 3.8 cm; and S1-ankle (lower-extremity gain), 3.3 cm (p < 0.001). T1-S1 height gain correlated with the thoracic Cobb angle correction and the maximum Cobb angle correction (p = 0.002). S1-ankle height gain correlated with the corrections in PT, PI-LL, and SVA (p < 0.001). T1-ankle height gain correlated with the corrections in PT (p < 0.001) and SVA (p = 0.03). Trunk height gain correlated with improved Scoliosis Research Society (SRS-22r) Appearance scores (r = 0.20; p = 0.02). Patient-Reported Outcomes Measurement Information System (PROMIS) Depression scores correlated with S1-ankle height gain (r = -0.19; p = 0.03) and C2-T1 height gain (r = -0.18; p = 0.04). A 1° correction in a thoracic scoliosis Cobb angle corresponded to a 0.2-mm height gain, and a 1° correction in a thoracolumbar scoliosis Cobb angle resulted in a 0.25-mm height gain. A 1° improvement in PI-LL resulted in a 0.2-mm height gain.Conclusions
Most patients undergoing ASD surgery experienced height gain following deformity correction, with a mean full-body height gain of 7.6 cm. Height gain can be estimated preoperatively with predictive ratios, and height gain was correlated with improvements in reported SRS-22r appearance and PROMIS scores.Level of evidence
Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.Item Open Access Hip Osteoarthritis in Patients Undergoing Surgery for Severe Adult Spinal Deformity: Prevalence and Impact on Spine Surgery Outcomes.(The Journal of bone and joint surgery. American volume, 2024-07) Diebo, Bassel G; Alsoof, Daniel; Balmaceno-Criss, Mariah; Daher, Mohammad; Lafage, Renaud; Passias, Peter G; Ames, Christopher P; Shaffrey, Christopher I; Burton, Douglas C; Deviren, Vedat; Line, Breton G; Soroceanu, Alex; Hamilton, D Kojo; Klineberg, Eric O; Mundis, Gregory M; Kim, Han Jo; Gum, Jeffrey L; Smith, Justin S; Uribe, Juan S; Kebaish, Khaled M; Gupta, Munish C; Nunley, Pierce D; Eastlack, Robert K; Hostin, Richard; Protopsaltis, Themistocles S; Lenke, Lawrence G; Hart, Robert A; Schwab, Frank J; Bess, Shay; Lafage, Virginie; Daniels, Alan H; International Spine Study GroupBackground
Hip osteoarthritis (OA) is common in patients with adult spinal deformity (ASD). Limited data exist on the prevalence of hip OA in patients with ASD, or on its impact on baseline and postoperative alignment and patient-reported outcome measures (PROMs). Therefore, this paper will assess the prevalence and impact of hip OA on alignment and PROMs.Methods
Patients with ASD who underwent L1-pelvis or longer fusions were included. Two independent reviewers graded hip OA with the Kellgren-Lawrence (KL) classification and stratified it by severity into non-severe (KL grade 1 or 2) and severe (KL grade 3 or 4). Radiographic parameters and PROMs were compared among 3 patient groups: Hip-Spine (hip KL grade 3 or 4 bilaterally), Unilateral (UL)-Hip (hip KL grade 3 or 4 unilaterally), or Spine (hip KL grade 1 or 2 bilaterally).Results
Of 520 patients with ASD who met inclusion criteria for an OA prevalence analysis, 34% (177 of 520) had severe bilateral hip OA and unilateral or bilateral hip arthroplasty had been performed in 8.7% (45 of 520). A subset of 165 patients had all data components and were examined: 68 Hip-Spine, 32 UL-Hip, and 65 Spine. Hip-Spine patients were older (67.9 ± 9.5 years, versus 59.6 ± 10.1 years for Spine and 65.8 ± 7.5 years for UL-Hip; p < 0.001) and had a higher frailty index (4.3 ± 2.6, versus 2.7 ± 2.0 for UL-Hip and 2.9 ± 2.0 for Spine; p < 0.001). At 1 year, the groups had similar lumbar lordosis, yet the Hip-Spine patients had a worse sagittal vertebral axis (SVA) measurement (45.9 ± 45.5 mm, versus 25.1 ± 37.1 mm for UL-Hip and 19.0 ± 39.3 mm for Spine; p = 0.001). Hip-Spine patients also had worse Veterans RAND-12 Physical Component Summary scores at baseline (25.7 ± 9.3, versus 28.7 ± 9.8 for UL-Hip and 31.3 ± 10.5 for Spine; p = 0.005) and 1 year postoperatively (34.5 ± 11.4, versus 40.3 ± 10.4 for UL-Hip and 40.1 ± 10.9 for Spine; p = 0.006).Conclusions
This study of operatively treated ASD revealed that 1 in 3 patients had severe hip OA bilaterally. Such patients with severe bilateral hip OA had worse baseline SVA and PROMs that persisted 1 year following ASD surgery, despite correction of lordosis.Level of evidence
Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.Item Open Access Impact of case type, length of stay, institution type, and comorbidities on Medicare diagnosis-related group reimbursement for adult spinal deformity surgery.(Neurosurgical focus, 2017-12) Nunley, Pierce D; Mundis, Gregory M; Fessler, Richard G; Park, Paul; Zavatsky, Joseph M; Uribe, Juan S; Eastlack, Robert K; Chou, Dean; Wang, Michael Y; Anand, Neel; Frank, Kelly A; Stone, Marcus B; Kanter, Adam S; Shaffrey, Christopher I; Mummaneni, Praveen V; International Spine Study GroupOBJECTIVE The aim of this study was to educate medical professionals about potential financial impacts of improper diagnosis-related group (DRG) coding in adult spinal deformity (ASD) surgery. METHODS Medicare's Inpatient Prospective Payment System PC Pricer database was used to collect 2015 reimbursement data for ASD procedures from 12 hospitals. Case type, hospital type/location, number of operative levels, proper coding, length of stay, and complications/comorbidities (CCs) were analyzed for effects on reimbursement. DRGs were used to categorize cases into 3 types: 1) anterior or posterior only fusion, 2) anterior fusion with posterior percutaneous fixation with no dorsal fusion, and 3) combined anterior and posterior fixation and fusion. RESULTS Pooling institutions, cases were reimbursed the same for single-level and multilevel ASD surgery. Longer stay, from 3 to 8 days, resulted in an additional $1400 per stay. Posterior fusion was an additional $6588, while CCs increased reimbursement by approximately $13,000. Academic institutions received higher reimbursement than private institutions, i.e., approximately $14,000 (Case Types 1 and 2) and approximately $16,000 (Case Type 3). Urban institutions received higher reimbursement than suburban institutions, i.e., approximately $3000 (Case Types 1 and 2) and approximately $3500 (Case Type 3). Longer stay, from 3 to 8 days, increased reimbursement between $208 and $494 for private institutions and between $1397 and $1879 for academic institutions per stay. CONCLUSIONS Reimbursement is based on many factors not controlled by surgeons or hospitals, but proper DRG coding can significantly impact the financial health of hospitals and availability of quality patient care.Item Open Access Impact of Hip and Knee Osteoarthritis on Full Body Sagittal Alignment and Compensation for Sagittal Spinal Deformity.(Spine, 2024-02) Balmaceno-Criss, Mariah; Lafage, Renaud; Alsoof, Daniel; Daher, Mohammad; Hamilton, David Kojo; Smith, Justin S; Eastlack, Robert K; Fessler, Richard G; Gum, Jeffrey L; Gupta, Munish C; Hostin, Richard; Kebaish, Khaled M; Klineberg, Eric O; Lewis, Stephen J; Line, Breton G; Nunley, Pierce D; Mundis, Gregory M; Passias, Peter G; Protopsaltis, Themistocles S; Buell, Thomas; Scheer, Justin K; Mullin, Jeffrey P; Soroceanu, Alex; Ames, Christopher P; Lenke, Lawrence G; Bess, Shay; Shaffrey, Christopher I; Schwab, Frank J; Lafage, Virginie; Burton, Douglas C; Diebo, Bassel G; Daniels, Alan H; International Spine Study Group (ISSG)Study design
Retrospective review of prospectively collected data.Objective
To investigate the effect of lower extremity osteoarthritis on sagittal alignment and compensatory mechanisms in adult spinal deformity (ASD).Background
Spine, hip, and knee pathologies often overlap in ASD patients. Limited data exists on how lower extremity osteoarthritis impacts sagittal alignment and compensatory mechanisms in ASD.Methods
527 pre-operative ASD patients with full body radiographs were included. Patients were grouped by Kellgren-Lawrence grade of bilateral hips and knees and stratified by quartile of T1-Pelvic Angle (T1PA) severity into low-, mid-, high-, and severe-T1PA. Full body alignment and compensation were compared across quartiles. Regression analysis examined the incremental impact of hip and knee osteoarthritis severity on compensation.Results
The mean T1PA for low-, mid-, high-, and severe-T1PA groups was 7.3°, 19.5°, 27.8°, 41.6°, respectively. Mid-T1PA patients with severe hip osteoarthritis had an increased sagittal vertical axis and global sagittal alignment (P<0.001). Increasing hip osteoarthritis severity resulted in decreased pelvic tilt (P=0.001) and sacrofemoral angle (P<0.001), but increased knee flexion (P=0.012). Regression analysis revealed with increasing T1PA, pelvic tilt correlated inversely with hip osteoarthritis and positively with knee osteoarthritis (r2=0.812). Hip osteoarthritis decreased compensation via sacrofemoral angle (β-coefficient=-0.206). Knee and hip osteoarthritis contributed to greater knee flexion (β-coefficients=0.215, 0.101; respectively). For pelvic shift, only hip osteoarthritis significantly contributed to the model (β-coefficient=0.100).Conclusions
For the same magnitude of spinal deformity, increased hip osteoarthritis severity was associated with worse truncal and full body alignment with posterior translation of the pelvis. Patients with severe hip and knee osteoarthritis exhibited decreased hip extension and pelvic tilt, but increased knee flexion. This examines sagittal alignment and compensation in ASD patients with hip and knee arthritis and may help delineate whether hip and knee flexion is due to spinal deformity compensation or lower extremity osteoarthritis.Item Open Access Impact of Self-Reported Loss of Balance and Gait Disturbance on Outcomes following Adult Spinal Deformity Surgery.(Journal of clinical medicine, 2024-04) Diebo, Bassel G; Alsoof, Daniel; Lafage, Renaud; Daher, Mohammad; Balmaceno-Criss, Mariah; Passias, Peter G; Ames, Christopher P; Shaffrey, Christopher I; Burton, Douglas C; Deviren, Vedat; Line, Breton G; Soroceanu, Alex; Hamilton, David Kojo; Klineberg, Eric O; Mundis, Gregory M; Kim, Han Jo; Gum, Jeffrey L; Smith, Justin S; Uribe, Juan S; Kebaish, Khaled M; Gupta, Munish C; Nunley, Pierce D; Eastlack, Robert K; Hostin, Richard; Protopsaltis, Themistocles S; Lenke, Lawrence G; Hart, Robert A; Schwab, Frank J; Bess, Shay; Lafage, Virginie; Daniels, Alan H; ISSGBackground: The objective of this study was to evaluate if imbalance influences complication rates, radiological outcomes, and patient-reported outcomes (PROMs) following adult spinal deformity (ASD) surgery. Methods: ASD patients with baseline and 2-year radiographic and PROMs were included. Patients were grouped according to whether they answered yes or no to a recent history of pre-operative loss of balance. The groups were propensity-matched by age, pelvic incidence-lumbar lordosis (PI-LL), and surgical invasiveness score. Results: In total, 212 patients were examined (106 in each group). Patients with gait imbalance had worse baseline PROM measures, including Oswestry disability index (45.2 vs. 36.6), SF-36 mental component score (44 vs. 51.8), and SF-36 physical component score (p < 0.001 for all). After 2 years, patients with gait imbalance had less pelvic tilt correction (-1.2 vs. -3.6°, p = 0.039) for a comparable PI-LL correction (-11.9 vs. -15.1°, p = 0.144). Gait imbalance patients had higher rates of radiographic proximal junctional kyphosis (PJK) (26.4% vs. 14.2%) and implant-related complications (47.2% vs. 34.0%). After controlling for age, baseline sagittal parameters, PI-LL correction, and comorbidities, patients with imbalance had 2.2-times-increased odds of PJK after 2 years. Conclusions: Patients with a self-reported loss of balance/unsteady gait have significantly worse PROMs and higher risk of PJK.Item Open Access Incidence of Acute, Progressive, and Delayed Proximal Junctional Kyphosis Over an 8-Year Period in Adult Spinal Deformity Patients.(Operative neurosurgery (Hagerstown, Md.), 2020-01) Segreto, Frank A; Passias, Peter G; Lafage, Renaud; Lafage, Virginie; Smith, Justin S; Line, Breton G; Mundis, Gregory M; Bortz, Cole A; Stekas, Nicholas D; Horn, Samantha R; Diebo, Bassel G; Brown, Avery E; Ihejirika, Yael; Nunley, Pierce D; Daniels, Alan H; Gupta, Munish C; Gum, Jeffrey L; Hamilton, D Kojo; Klineberg, Eric O; Burton, Douglas C; Hart, Robert A; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher PBackground
Proximal junctional kyphosis (PJK) is a common radiographic complication of adult spinal deformity (ASD) corrective surgery. Although previous literature has reported a 5 to 61% incidence of PJK, these studies are limited by small sample sizes and short-term follow-up.Objective
To assess the incidence of PJK utilizing a high-powered ASD database.Methods
Retrospective review of a prospective multicenter ASD database. Operative ASD patients > 18 yr old from 2009 to 2017 were included. PJK was defined as ≥ 10° for the sagittal Cobb angle between the inferior upper instrumented vertebra (UIV) endplate and the superior endplate of the UIV + 2. Chi-square analysis and post hoc testing assessed annual and overall incidence of acute (6-wk follow-up [f/u]), progressive (increase in degree of PJK from 6 wk to 1 yr), and delayed (1-yr, 2-yr, and 3-yr f/u) PJK development.Results
A total of 1005 patients were included (age: 59.3; 73.5% F; body mass index: 27.99). Overall PJK incidence was 69.4%. Overall incidence of acute PJK was 48.0%. Annual incidence of acute PJK has decreased from 53.7% in 2012 to 31.6% in 2017 (P = .038). Overall incidence of progressive PJK was 35.0%, with stable rates observed from 2009 to 2016 (P = .297). Overall incidence of 1-yr-delayed PJK was 9.3%. Annual incidence of 1-yr-delayed PJK has decreased from 9.2% in 2009 to 3.2% in 2016 (P < .001). Overall incidence of 2-yr-delayed PJK development was 4.3%. Annual incidence of 2-yr-delayed PJK has decreased from 7.3% in 2009 to 0.9% in 2015 (P < .05). Overall incidence of 3-yr-delayed PJK was 1.8%, with stable rates observed from 2009 to 2014 (P = .594).Conclusion
Although progressive PJK has remained a challenge for physicians over time, significantly lower incidences of acute and delayed PJK in recent years may indicate improving operative decision-making and management strategies.Item Open Access Incremental benefits of circumferential minimally invasive surgery for increasingly frail patients with adult spinal deformity.(Journal of neurosurgery. Spine, 2023-04) Passias, Peter G; Tretiakov, Peter S; Nunley, Pierce D; Wang, Michael Y; Park, Paul; Kanter, Adam S; Okonkwo, David O; Eastlack, Robert K; Mundis, Gregory M; Chou, Dean; Agarwal, Nitin; Fessler, Richard G; Uribe, Juan S; Anand, Neel; Than, Khoi D; Brusko, Gregory; Fu, Kai-Ming; Turner, Jay D; Le, Vivian P; Line, Breton G; Ames, Christopher P; Smith, Justin S; Shaffrey, Christopher I; Hart, Robert A; Burton, Douglas; Lafage, Renaud; Lafage, Virginie; Schwab, Frank; Bess, Shay; Mummaneni, Praveen VObjective
Circumferential minimally invasive surgery (cMIS) may provide incremental benefits compared with open surgery for patients with increasing frailty status by decreasing peri- and postoperative complications.Methods
Operative patients with adult spinal deformity (ASD) ≥ 18 years old with baseline and 2-year postoperative data were assessed. With propensity score matching, patients who underwent cMIS (cMIS group) were matched with similar patients who underwent open surgery (open group) based on baseline BMI, C7-S1 sagittal vertical axis, pelvic incidence to lumbar lordosis mismatch, and S1 pelvic tilt. The Passias modified ASD frailty index (mASD-FI) was used to determine patient frailty stratification as not frail, frail, or severely frail. Baseline and postoperative factors were assessed using two-way analysis of covariance (ANCOVA) and multivariate ANCOVA while controlling for baseline age, Charlson Comorbidity Index (CCI) score, and number of levels fused.Results
After propensity score matching, 170 ASD patients (mean age 62.71 ± 13.64 years, 75.0% female, mean BMI 29.25 ± 6.60 kg/m2) were included, split evenly between the cMIS and open groups. Surgically, patients in the open group had higher numbers of posterior levels fused (p = 0.021) and were more likely to undergo three-column osteotomies (p > 0.05). Perioperatively, cMIS patients had lower intraoperative blood loss and decreased use of cell saver across frailty groups (with adjustment for baseline age, CCI score, and levels fused), as well as fewer perioperative complications (p < 0.001). Adjusted analysis also revealed that compared to open patients, increasingly frail patients in the cMIS group were also more likely to demonstrate greater improvement in 1- and 2-year postoperative scores for the Oswestry Disability Index, SRS-36 (total), EQ-5D and SF-36 (all p < 0.05). With regard to postoperative complications, increasingly frail patients in the cMIS group were also noted to experience significantly fewer complications overall (p = 0.036) and fewer major intraoperative complications (p = 0.039). The cMIS patients were also less likely to need a reoperation than their open group counterparts (p = 0.043).Conclusions
Surgery performed with a cMIS technique may offer acceptable outcomes, with diminishment of perioperative complications and mitigation of catastrophic outcomes, in increasingly frail patients who may not be candidates for surgery using traditional open techniques. However, further studies should be performed to investigate the long-term impact of less optimal alignment in this population.Item Open Access Interspinous Process Decompression Improves Quality of Life in Patients with Lumbar Spinal Stenosis(Minimally Invasive Surgery, 2018-07-02) Nunley, Pierce D; Patel, Vikas V; Orndorff, Douglas G; Lavelle, William F; Block, Jon E; Geisler, Fred HLumbar spinal stenosis has been shown to negatively impact health-related quality of life. Interspinous process decompression (IPD) is a minimally invasive procedure that utilizes a stand-alone spacer to serve as a joint extension blocker to relieve neural compression in patients with spinal stenosis. Using the 5-year results from an FDA randomized controlled trial of IPD, the quality of life in 189 patients treated with the Superion® spacer was evaluated with the SF-12. Physical and mental component summary (PCS, MCS) scores were computed preoperatively and at annual intervals. For the PCS, mean scores improved from 29.4 ± 8.1 preoperatively to 41.2 ± 12.4 at 2 years (40%) and to 43.8 ± 11.6 at 5 years (49%) (p<0.001 for both comparisons). At 2 years, 81% (103 of 128) of subjects demonstrated maintenance or improvement in PCS scores. The mean MCS score improved from 50.0 ± 12.7 preoperatively to 54.4 ± 10.6 and 54.7 ± 8.6 at 2 and 5 years, respectively (p>0.10 for both comparisons). These results demonstrate that the significant impairment in physical well-being found in patients with lumbar spinal stenosis can be ameliorated, in large part, by IPD treatment.Item Open Access Interspinous Process Decompression: Expanding Treatment Options for Lumbar Spinal Stenosis(BioMed Research International, 2016) Nunley, Pierce D; Shamie, A Nick; Blumenthal, Scott L; Orndorff, Douglas; Block, Jon E; Geisler, Fred HInterspinous process decompression is a minimally invasive implantation procedure employing a stand-alone interspinous spacer that functions as an extension blocker to prevent compression of neural elements without direct surgical removal of tissue adjacent to the nerves. The Superion® spacer is the only FDA approved stand-alone device available in the US. It is also the only spacer approved by the CMS to be implanted in an ambulatory surgery center. We computed the within-group effect sizes from the Superion IDE trial and compared them to results extrapolated from two randomized trials of decompressive laminectomy. For the ODI, effect sizes were allvery large(>1.0) for Superion and laminectomy at 2, 3, and 4 years. For ZCQ, the 2-year Superion symptom severity (1.26) and physical function (1.29) domains werevery large; laminectomy effect sizes werevery large(1.07) for symptom severity andlargefor physical function (0.80). Current projections indicate a marked increase in the number of patients with spinal stenosis. Consequently, there remains a keen interest in minimally invasive treatment options that delay or obviate the need for invasive surgical procedures, such as decompressive laminectomy or fusion. Stand-alone interspinous spacers may fill a currently unmet treatment gap in the continuum of care and help to reduce the burden of this chronic degenerative condition on the health care system.Item Open Access Less invasive spinal deformity surgery: the impact of the learning curve at tertiary spine care centers.(Journal of neurosurgery. Spine, 2019-08) Wang, Michael Y; Tran, Stacie; Brusko, G Damian; Eastlack, Robert; Park, Paul; Nunley, Pierce D; Kanter, Adam S; Uribe, Juan S; Anand, Neel; Okonkwo, David O; Than, Khoi D; Shaffrey, Christopher I; Lafage, Virginie; Mundis, Gregory M; Mummaneni, Praveen V; MIS-ISSG GroupObjective
The past decade has seen major advances in techniques for treating more complex spinal disorders using minimally invasive surgery (MIS). While appealing from the standpoint of patient perioperative outcomes, a major impediment to adoption has been the significant learning curve in utilizing MIS techniques.Methods
Data were retrospectively analyzed from a multicenter series of adult spinal deformity surgeries treated at eight tertiary spine care centers in the period from 2008 to 2015. All patients had undergone a less invasive or hybrid approach for a deformity correction satisfying the following inclusion criteria at baseline: coronal Cobb angle ≥ 20°, sagittal vertical axis (SVA) > 5 cm, or pelvic tilt > 20°. Analyzed data included baseline demographic details, severity of deformity, surgical metrics, clinical outcomes (numeric rating scale [NRS] score and Oswestry Disability Index [ODI]), radiographic outcomes, and complications. A minimum follow-up of 2 years was required for study inclusion.Results
Across the 8-year study period, among 222 patients, there was a trend toward treating increasingly morbid patients, with the mean age increasing from 50.7 to 62.4 years (p = 0.013) and the BMI increasing from 25.5 to 31.4 kg/m2 (p = 0.12). There was no statistical difference in the severity of coronal and sagittal deformity treated over the study period. With regard to radiographic changes following surgery, there was an increasing emphasis on sagittal correction and, conversely, less coronal correction. There was no statistically significant difference in clinical outcomes over the 8-year period, and meaningful improvements were seen in all years (ODI range of improvement: 15.0-26.9). Neither were there statistically significant differences in major complications; however, minor complications were seen less often as the surgeons gained experience (p = 0.064). Operative time was decreased on average by 47% over the 8-year period.Trends in surgical practice were seen as well. Total fusion construct length was unchanged until the last year when there was a marked decrease in conjunction with a decrease in interbody levels treated (p = 0.004) while obtaining a higher degree of sagittal correction, suggesting more selective but powerful interbody reduction methods as reflected by an increase in the lateral and anterior column resection techniques being utilized.Conclusions
The use of minimally invasive methods for adult spinal deformity surgery has evolved over the past decade. Experienced surgeons are treating older and more morbid patients with similar outcomes. A reliance on selective, more powerful interbody approaches is increasing as well.Item Open Access Lumbar Lordosis Redistribution and Segmental Correction in Adult Spinal Deformity (ASD): Does it Matter?(Spine, 2024-01) Diebo, Bassel G; Balmaceno-Criss, Mariah; Lafage, Renaud; Daher, Mohammad; Singh, Manjot; Hamilton, D Kojo; Smith, Justin S; Eastlack, Robert K; Fessler, Richard; Gum, Jeffrey L; Gupta, Munish C; Hostin, Richard; Kebaish, Khaled M; Lewis, Stephen; Line, Breton G; Nunley, Pierce D; Mundis, Gregory M; Passias, Peter G; Protopsaltis, Themistocles S; Turner, Jay; Buell, Thomas; Scheer, Justin K; Mullin, Jeffery; Soroceanu, Alex; Ames, Christopher P; Bess, Shay; Shaffrey, Christopher I; Lenke, Lawrence G; Schwab, Frank J; Lafage, Virginie; Burton, Douglas C; Daniels, Alan H; International Spine Study Group (ISSG)Study design
Retrospective analysis of prospectively collected data.Objective
Evaluate the impact of correcting to normative segmental lordosis values on post-operative outcomes.Background
Restoring lumbar lordosis magnitude is crucial in adult spinal deformity surgery, but the optimal location and segmental distribution remains unclear.Methods
Patients were grouped based on offset to normative segmental lordosis values, extracted from recent publications. Matched patients were within 10% of the cohort's mean offset, less than or over 10% were under- and over-corrected. Surgical technique, PROMs, and surgical complications were compared across groups at baseline and 2-year.Results
510 patients with an average age of 64.6, mean CCI 2.08, and average follow-up of 25 months. L4-5 was least likely to be matched (19.1%), while L4-S1 was the most likely (24.3%). More patients were overcorrected at proximal levels (T10-L2; Undercorrected, U: 32.2% vs. Matched, M: 21.7% vs. Overcorrected, O: 46.1%) and undercorrected at distal levels (L4-S1: U: 39.0% vs. M: 24.3% vs. O: 36.8%). Postoperative ODI was comparable across correction groups at all spinal levels except at L4-S1 and T10-L2/L4-S1, where overcorrected patients and matched were better than undercorrected (U: 32.1 vs. M: 25.4 vs. O: 26.5, P=0.005; U: 36.2 vs. M: 24.2 vs. O: 26.8, P=0.001; respectively). Patients overcorrected at T10-L2 experienced higher rates of proximal junctional failure (PJF) (U: 16.0% vs. M: 15.6% vs. O: 32.8%, P<0.001) and had greater posterior inclination of the upper instrumented vertebra (UIV) (U: -9.2±9.4° vs. M: -9.6±9.1° vs. O: -12.2±10.0°, P<0.001), whereas undercorrection at these levels led to higher rates of revision for implant failure (U: 14.2% vs. M: 7.3% vs. O: 6.4%, P=0.025).Conclusions
Patients undergoing fusion for adult spinal deformity suffer higher rates of PJF with overcorrection and increased rates of implant failure with undercorrection based on normative segmental lordosis.Level of evidence
IV.Item Open Access Predicting the combined occurrence of poor clinical and radiographic outcomes following cervical deformity corrective surgery.(Journal of neurosurgery. Spine, 2019-11) Horn, Samantha R; Passias, Peter G; Oh, Cheongeun; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Line, Breton; Anand, Neel; Segreto, Frank A; Bortz, Cole A; Scheer, Justin K; Eastlack, Robert K; Deviren, Vedat; Mummaneni, Praveen V; Daniels, Alan H; Park, Paul; Nunley, Pierce D; Kim, Han Jo; Klineberg, Eric O; Burton, Douglas C; Hart, Robert A; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study GroupOBJECTIVE:Cervical deformity (CD) correction is clinically challenging. There is a high risk of developing complications with these highly complex procedures. The aim of this study was to use baseline demographic, clinical, and surgical factors to predict a poor outcome following CD surgery. METHODS:The authors performed a retrospective review of a multicenter prospective CD database. CD was defined as at least one of the following: cervical kyphosis (C2-7 Cobb angle > 10°), cervical scoliosis (coronal Cobb angle > 10°), C2-7 sagittal vertical axis (cSVA) > 4 cm, or chin-brow vertical angle (CBVA) > 25°. Patients were categorized based on having an overall poor outcome or not. Health-related quality of life measures consisted of Neck Disability Index (NDI), EQ-5D, and modified Japanese Orthopaedic Association (mJOA) scale scores. A poor outcome was defined as having all 3 of the following categories met: 1) radiographic poor outcome: deterioration or severe radiographic malalignment 1 year postoperatively for cSVA or T1 slope-cervical lordosis mismatch (TS-CL); 2) clinical poor outcome: failing to meet the minimum clinically important difference (MCID) for NDI or having a severe mJOA Ames modifier; and 3) complications/reoperation poor outcome: major complication, death, or reoperation for a complication other than infection. Univariate logistic regression followed by multivariate regression models was performed, and internal validation was performed by calculating the area under the curve (AUC). RESULTS:In total, 89 patients with CD were included (mean age 61.9 years, female sex 65.2%, BMI 29.2 kg/m2). By 1 year postoperatively, 18 (20.2%) patients were characterized as having an overall poor outcome. For radiographic poor outcomes, patients' conditions either deteriorated or remained severe for TS-CL (73% of patients), cSVA (8%), horizontal gaze (34%), and global SVA (28%). For clinical poor outcomes, 80% and 60% of patients did not reach MCID for EQ-5D and NDI, respectively, and 24% of patients had severe symptoms (mJOA score 0-11). For the complications/reoperation poor outcome, 28 patients experienced a major complication, 11 underwent a reoperation, and 1 had a complication-related death. Of patients with a poor clinical outcome, 75% had a poor radiographic outcome; 35% of poor radiographic and 37% of poor clinical outcome patients had a major complication. A poor outcome was predicted by the following combination of factors: osteoporosis, baseline neurological status, use of a transition rod, number of posterior decompressions, baseline pelvic tilt, T2-12 kyphosis, TS-CL, C2-T3 SVA, C2-T1 pelvic angle (C2 slope), global SVA, and number of levels in maximum thoracic kyphosis. The final model predicting a poor outcome (AUC 86%) included the following: osteoporosis (OR 5.9, 95% CI 0.9-39), worse baseline neurological status (OR 11.4, 95% CI 1.8-70.8), baseline pelvic tilt > 20° (OR 0.92, 95% CI 0.85-0.98), > 9 levels in maximum thoracic kyphosis (OR 2.01, 95% CI 1.1-4.1), preoperative C2-T3 SVA > 5.4 cm (OR 1.01, 95% CI 0.9-1.1), and global SVA > 4 cm (OR 3.2, 95% CI 0.09-10.3). CONCLUSIONS:Of all CD patients in this study, 20.2% had a poor overall outcome, defined by deterioration in radiographic and clinical outcomes, and a major complication. Additionally, 75% of patients with a poor clinical outcome also had a poor radiographic outcome. A poor overall outcome was most strongly predicted by severe baseline neurological deficit, global SVA > 4 cm, and including more of the thoracic maximal kyphosis in the construct.Item Open Access Prevalence and Prognosis of Coronal Malalignment Following Lateral Lumbar Interbody Fusion for Minimally Invasive Treatment of Adult Spinal Deformity.(Spine, 2024-11) Chan, Andrew K; Sampath, Shailen G; Mummaneni, Praveen V; Park, Paul; Uribe, Juan S; Turner, Jay D; Le, Vivian P; Eastlack, Robert K; Fessler, Richard G; Than, Khoi D; Fu, Kai-Ming; Wang, Michael Y; Kanter, Adam S; Okonkwo, David O; Nunley, Pierce D; Anand, Neel; Mundis, Gregory M; Passias, Peter G; Bess, Shay; Shaffrey, Christopher I; Chou, Dean; International Spine Study GroupStudy design
Retrospective analysis of prospective multicenter adult spinal deformity (ASD) database.Objective
To determine the prevalence and prognosis of postoperative coronal malalignment following LLIF for ASD with Qiu type A coronal alignment.Summary of background data
Qiu Type A coronal alignment is defined as coronal vertical axis (CVA) <30mm.1 There is concern that circumferential minimally invasive surgery (cMIS) with lateral lumbar interbody fusion (LLIF) is associated with postoperative coronal malalignment in ASD with preoperative Qiu type A patients.Methods
Qui type A patients undergoing cMIS with LLIF for ASD were included, with ASD defined with at least: maximum CC≥20°, SVA>5 cm, PI-LL≥10°, or PT>20°. Two year (2Y) clinical outcomes were compared for type A with 2Y CVA≥30 mm (MAL) versus <30 mm (ALIGN) and were adjusted for factors reaching P<0.05 on univariate comparisons (age, BMI, and ODI).Results
43 patients met inclusion criteria, of which 12 (27.9%) developed coronal malalignment and 31 (72.1%) remained coronally aligned at 2Y. At baseline, MAL were older (73.0 vs. 69.0, P=0.045), had a lower BMI (26.09 vs. 29.45, P=0.047), and were less disabled (ODI 42.83 vs. 51.69, P=0.016). Otherwise, the groups were well-matched for baseline characteristics. At 2Y, MAL had a greater 2Y SVA (mean 54.08 vs 19.00 mm, P=0.01). Clinically, MAL was associated with inferior 2Y SF-36 PCS (34.78 vs. 37.42, adj P=0.043) and 2Y SRS-22r function/activity domain (3.03 vs. 3.36, adj P=0.040), but otherwise similar in other patient-reported-outcome-metrics (adj P>0.05 for all). 2Y complications were similar between groups, including for reoperations and major and minor complications (adj P>0.05 for all).Conclusions
In Qui type A patients undergoing cMIS with LLIF for ASD, 27.9% develop coronal malalignment, which was associated with worse SF-36 PCS and SRS-22r function/activity. Despite radiographic malalignment, malalignment was not associated with higher 2-year complication rates including reoperations.