Browsing by Author "Gupta, Munish C"
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Item Open Access Adult Spinal Deformity Knowledge in Orthopedic Spine Surgeons: Impact of Fellowship Training, Experience, and Practice Characteristics.(Spine deformity, 2018-01) Grabel, Zachary J; Hart, Robert A; Clark, Aaron J; Park, Sara Heejung; Shaffrey, Christopher I; Scheer, Justin K; Smith, Justin S; Kelly, Michael P; DePasse, J Mason; Gupta, Munish C; Ames, Christopher P; Daniels, Alan HSTUDY DESIGN:Survey study. OBJECTIVE:The purpose of this paper was to assess the level of adult spine deformity (ASD) knowledge among orthopedic spine surgeons and identify areas for improvement in spine surgery training. SUMMARY OF BACKGROUND DATA:ASD is increasingly encountered in spine surgery practice. While ASD knowledge among neurosurgeons has been evaluated, ASD knowledge among orthopedic spine surgeons has not previously been reported. METHODS:A survey of orthopedic spine surgeon members of North American Spine Society (NASS) was conducted to assess level of spine surgery training, practice experience, and spinal deformity knowledge base. The survey used was previously completed by a group of neurologic surgeons with published results. The survey used 11 questions developed and agreed upon by experienced spinal deformity surgeons. RESULTS:Complete responses were received from 413 orthopedic spine surgeons. The overall correct-answer rate was 69.0%. Surgeons in practice for less than 10 years had a higher correct-answer rate compared to those who have practiced for 10 years or more (74% vs. 67%; p = .000003). Surgeons with 75% or more of their practice dedicated to spine had a higher overall correct rate compared to surgeons whose practice is less than 75% spine (71% vs. 63%; p = .000029). Completion of spine fellowship was associated with a higher overall correct-answer rate compared to respondents who did not complete a spine fellowship (71% vs. 59%; p < .00001). CONCLUSIONS:Completion of spine fellowship and having a dedicated spine surgery practice were significantly associated with improved performance on this ASD knowledge survey. Unlike neurosurgeons, orthopedic spine surgeons who have practiced for less than 10 years performed better than those who have practiced for more than 10 years. Ongoing emphasis on spine deformity education should be emphasized to improve adult spinal deformity knowledge base.Item Open Access Alterations in Magnitude and Shape of Thoracic Kyphosis Following Surgical Correction for Adult Spinal Deformity.(Global spine journal, 2023-11) Lafage, Renaud; Song, Junho; Diebo, Bassel; Daniels, Alan H; Passias, Peter G; Ames, Christopher P; Bess, Shay; Eastlack, Robert; Gupta, Munish C; Hostin, Richard; Kebaish, Khaled; Kim, Han Jo; Klineberg, Eric; Mundis, Gregory M; Smith, Justin S; Shaffrey, Christopher; Schwab, Frank; Lafage, Virginie; Burton, Douglas; International Spine Study GroupStudy design
Retrospective review of prospective multicenter data.Objectives
This study aimed to investigate the shape of TK before and after fusion in ASD patients treated with long fusion.Methods
ASD patients undergoing posterior spinal fusions including at least T5 to L1 without prior fusion extending to the thoracic spine were included. Patients were categorized based on the preoperative T1-T12 kyphosis into: Hypo-TK (if < 30°), Normal-TK, and Hyper-TK (if > 70°). Regional kyphosis at T10-L1 (Distal), T5-T10 (Middle), and T1-T5 (Proximal) and their relative contributions to total kyphosis were compared between groups, and the pre-to postoperative changes were investigated using paired t test.Results
In total, 329 patients were included in this analysis (mean age: 57 ± 16 years, 79.6% female). Preoperative T1-T12 TK for the entire cohort was 40.9 ± 2° (32% Hypo-TK, 11% Hyper-TK, 57% Normal-TK). The Hypo-TK group had the smallest distal TK (5.9 vs 17.1 & 26.0), and middle TK (8.0 vs 25.3 & 45.4), but the percentage of contribution to total kyphosis was not significantly different (Distal: 24.1% vs 34.1% vs 32.8%; Middle: 46.6% vs 53.9% vs 56.8%, all P > .1). Postoperatively, T1-12 TK increased significantly (40.9 ± 2.0° vs 57.8 ± 17.6°). Each group had a decrease in distal kyphosis (Hypo-TK 2.6 ± 10.4°; Normal-TK 8.9 ± 11.5°; Hyper-TK 14.9 ± 12°, all P < .05). The middle kyphosis significantly decreased for Hyper-TK (11.8 ± 12.4) and increased for both Normal-TK and Hypo-TK (3.8 ± 11° and 14.2 ± 11°). Proximal TK increased significantly for all groups by 14-18°. Deterioration from Normal-TK to Hyper-TK postoperatively was associated with lower rate of patient satisfaction (59.6% vs 77.3%, P = .032).Conclusions
Posterior spinal fusion for ASD alters the magnitude and shape of thoracic kyphosis. While 60% of patients had a normal TK at baseline, 30% of those patients developed iatrogenic hyperkyphosis postoperatively. Patients with baseline hypokyphosis were more likely to be corrected to normal TK than hyperkyphotic patients. Future research should investigate TK restoration in ASD and its impact on clinical outcomes and complications.Item Open Access Analysis of tranexamic acid usage in adult spinal deformity patients with relative contraindications: does it increase the risk of complications?(JOURNAL OF NEUROSURGERY-SPINE, 2024) Mullin, Jeffrey P; Soliman, Mohamed AR; Smith, Justin S; Kelly, Michael P; Buell, Thomas J; Diebo, Bassel; Scheer, Justin K; Line, Breton; Lafage, Virginie; Lafage, Renaud; Klineberg, Eric; Kim, Han Jo; Passias, Peter G; Gum, Jeffrey L; Kebaish, Khaled; Eastlack, Robert K; Daniels, Alan H; Soroceanu, Alex; Mundis, Gregory; Hostin, Richard; Protopsaltis, Themistocles S; Hamilton, D Kojo; Gupta, Munish C; Lewis, Stephen J; Schwab, Frank J; Lenke, Lawrence G; Shaffrey, Christopher I; Bess, Shay; Ames, Christopher P; Burton, DouglasItem Open Access Analysis of tranexamic acid usage in adult spinal deformity patients with relative contraindications: does it increase the risk of complications?(Journal of neurosurgery. Spine, 2024-03) Mullin, Jeffrey P; Soliman, Mohamed AR; Smith, Justin S; Kelly, Michael P; Buell, Thomas J; Diebo, Bassel; Scheer, Justin K; Line, Breton; Lafage, Virginie; Lafage, Renaud; Klineberg, Eric; Kim, Han Jo; Passias, Peter G; Gum, Jeffrey L; Kebaish, Khaled; Eastlack, Robert K; Daniels, Alan H; Soroceanu, Alex; Mundis, Gregory; Hostin, Richard; Protopsaltis, Themistocles S; Hamilton, D Kojo; Gupta, Munish C; Lewis, Stephen J; Schwab, Frank J; Lenke, Lawrence G; Shaffrey, Christopher I; Bess, Shay; Ames, Christopher P; Burton, DouglasObjective
Complex spinal deformity surgeries may involve significant blood loss. The use of antifibrinolytic agents such as tranexamic acid (TXA) has been proven to reduce perioperative blood loss. However, for patients with a history of thromboembolic events, there is concern of increased risk when TXA is used during these surgeries. This study aimed to assess whether TXA use in patients undergoing complex spinal deformity correction surgeries increases the risk of thromboembolic complications based on preexisting thromboembolic risk factors.Methods
Data were analyzed for adult patients who received TXA during surgical correction for spinal deformity at 21 North American centers between August 2018 and October 2022. Patients with preexisting thromboembolic events and other risk factors (history of deep venous thrombosis [DVT], pulmonary embolism [PE], myocardial infarction [MI], stroke, peripheral vascular disease, or cancer) were identified. Thromboembolic complication rates were assessed during the postoperative 90 days. Univariate and multivariate analyses were performed to assess thromboembolic outcomes in high-risk and low-risk patients who received intravenous TXA.Results
Among 411 consecutive patients who underwent complex spinal deformity surgery and received TXA intraoperatively, 130 (31.6%) were considered high-risk patients. There was no significant difference in thromboembolic complications between patients with and those without preexisting thromboembolic risk factors in univariate analysis (high-risk group vs low-risk group: 8.5% vs 2.8%, p = 0.45). Specifically, there were no significant differences between groups regarding the 90-day postoperative rates of DVT (high-risk group vs low-risk group: 1.5% vs 1.4%, p = 0.98), PE (2.3% vs 1.8%, p = 0.71), acute MI (1.5% vs 0%, p = 0.19), or stroke (0.8% vs 1.1%, p > 0.99). On multivariate analysis, high-risk status was not a significant independent predictor for any of the thromboembolic complications.Conclusions
Administration of intravenous TXA during the correction procedure did not change rates of thromboembolic events, acute MI, or stroke in this cohort of adult spinal deformity surgery patients.Item Open Access Are insufficient corrections a major factor in distal junctional kyphosis? A simulated analysis of cervical deformity correction using in-construct measurements.(Journal of neurosurgery. Spine, 2024-05) Ani, Fares; Sissman, Ethan; Woo, Dainn; Soroceanu, Alex; Mundis, Gregory; Eastlack, Robert K; Smith, Justin S; Hamilton, D Kojo; Kim, Han Jo; Daniels, Alan H; Klineberg, Eric O; Neuman, Brian; Sciubba, Daniel M; Gupta, Munish C; Kebaish, Khaled M; Passias, Peter G; Hart, Robert A; Bess, Shay; Shaffrey, Christopher I; Schwab, Frank J; Lafage, Virginie; Ames, Christopher P; Protopsaltis, Themistocles SObjective
The present study utilized recently developed in-construct measurements in simulations of cervical deformity surgery in order to assess undercorrection and predict distal junctional kyphosis (DJK).Methods
A retrospective review of a database of operative cervical deformity patients was analyzed for severe DJK and mild DJK. C2-lower instrumented vertebra (LIV) sagittal angle (SA) was measured postoperatively, and the correction was simulated in the preoperative radiograph in order to match the C2-LIV by using the planning software. Linear regression analysis that used C2 pelvic angle (CPA) and pelvic tilt (PT) determined the simulated PT that matched the virtual CPA. Linear regression analysis was used to determine the C2-T1 SA, C2-T4 SA, and C2-T10 SA that corresponded to DJK of 20° and cervical sagittal vertical axis (cSVA) of 40 mm.Results
Sixty-nine cervical deformity patients were included. Severe and mild DJK occurred in 11 (16%) and 22 (32%) patients, respectively; 3 (4%) required DJK revision. Simulated corrections demonstrated that severe and mild DJK patients had worse alignment compared to non-DJK patients in terms of cSVA (42.5 mm vs 33.0 mm vs 23.4 mm, p < 0.001) and C2-LIV SVA (68.9 mm vs 57.3 mm vs 36.8 mm, p < 0.001). Linear regression revealed the relationships between in-construct measures (C2-T1 SA, C2-T4 SA, and C2-T10 SA), cSVA, and change in DJK (all R > 0.57, p < 0.001). A cSVA of 40 mm corresponded to C2-T4 SA of 10.4° and C2-T10 SA of 28.0°. A DJK angle change of 10° corresponded to C2-T4 SA of 5.8° and C2-T10 SA of 20.1°.Conclusions
Simulated cervical deformity corrections demonstrated that severe DJK patients have insufficient corrections compared to patients without DJK. In-construct measures assess sagittal alignment within the fusion separate from DJK and subjacent compensation. They can be useful as intraoperative tools to gauge the adequacy of cervical deformity correction.Item Open Access Are We Focused on the Wrong Early Postoperative Quality Metrics? Optimal Realignment Outweighs Perioperative Risk in Adult Spinal Deformity Surgery.(Journal of clinical medicine, 2023-08) Passias, Peter G; Williamson, Tyler K; Mir, Jamshaid M; Smith, Justin S; Lafage, Virginie; Lafage, Renaud; Line, Breton; Daniels, Alan H; Gum, Jeffrey L; Schoenfeld, Andrew J; Hamilton, David Kojo; Soroceanu, Alex; Scheer, Justin K; Eastlack, Robert; Mundis, Gregory M; Diebo, Bassel; Kebaish, Khaled M; Hostin, Richard A; Gupta, Munish C; Kim, Han Jo; Klineberg, Eric O; Ames, Christopher P; Hart, Robert A; Burton, Douglas C; Schwab, Frank J; Shaffrey, Christopher I; Bess, Shay; On Behalf Of The International Spine Study GroupBackground
While reimbursement is centered on 90-day outcomes, many patients may still achieve optimal, long-term outcomes following adult spinal deformity (ASD) surgery despite transient short-term complications.Objective
Compare long-term clinical success and cost-utility between patients achieving optimal realignment and suboptimally aligned peers.Study design/setting
Retrospective cohort study of a prospectively collected multicenter database.Methods
ASD patients with two-year (2Y) data included. Groups were propensity score matched (PSM) for age, frailty, body mass index (BMI), Charlson Comorbidity Index (CCI), and baseline deformity. Optimal radiographic criteria are defined as meeting low deformity in all three (Scoliosis Research Society) SRS-Schwab parameters or being proportioned in Global Alignment and Proportionality (GAP). Cost-per-QALY was calculated for each time point. Multivariable logistic regression analysis and ANCOVA (analysis of covariance) adjusting for baseline disability and deformity (pelvic incidence (PI), pelvic incidence minus lumbar lordosis (PI-LL)) were used to determine the significance of surgical details, complications, clinical outcomes, and cost-utility.Results
A total of 930 patients were considered. Following PSM, 253 "optimal" (O) and 253 "not optimal" (NO) patients were assessed. The O group underwent more invasive procedures and had more levels fused. Analysis of complications by two years showed that the O group suffered less overall major (38% vs. 52%, p = 0.021) and major mechanical complications (12% vs. 22%, p = 0.002), and less reoperations (23% vs. 33%, p = 0.008). Adjusted analysis revealed O patients more often met MCID (minimal clinically important difference) in SF-36 PCS, SRS-22 Pain, and Appearance. Cost-utility-adjusted analysis determined that the O group generated better cost-utility by one year and maintained lower overall cost and costs per QALY (both p < 0.001) at two years.Conclusions
Fewer late complications (mechanical and reoperations) are seen in optimally aligned patients, leading to better long-term cost-utility overall. Therefore, the current focus on avoiding short-term complications may be counterproductive, as achieving optimal surgical correction is critical for long-term success.Item Open Access Are we improving in the optimization of surgery for high-risk adult cervical spine deformity patients over time?(Journal of neurosurgery. Spine, 2023-07) Passias, Peter G; Tretiakov, Peter S; Smith, Justin S; Lafage, Renaud; Diebo, Bassel; Scheer, Justin K; Eastlack, Robert K; Daniels, Alan H; Klineberg, Eric O; Khabeish, Khaled M; Mundis, Gregory M; Turner, Jay D; Gupta, Munish C; Kim, Han Jo; Schwab, Frank; Bess, Shay; Lafage, Virginie; Ames, Christopher P; Shaffrey, Christopher IObjective
The aim of this study was to investigate whether surgery for high-risk patients is being optimized over time and if poor outcomes are being minimized.Methods
Patients who underwent surgery for cervical deformity (CD) and were ≥ 18 years with baseline and 2-year data were stratified by year of surgery from 2013 to 2018. The cohort was divided into two groups based on when the surgery was performed. Patients in the early cohort underwent surgery between 2013 and 2015 and those in the recent cohort underwent surgery between 2016 and 2018. High-risk patients met at least 2 of the following criteria: 1) baseline C2-7 Cobb angle > 15°, mismatch between T1 slope and cervical lordosis ≥ 35°, C2-7 sagittal vertical axis > 4 cm, or chin-brow vertical angle > 25°; 2) age ≥ 70 years; 3) severe baseline frailty (Miller index); 4) Charlson Comorbidity Index (CCI) ≥ 1 SD above the mean; 5) three-column osteotomy as treatment; and 6) fusion > 10 levels or > 7 levels for elderly patients. The mean comparison analysis assessed differences between groups. Stepwise multivariable linear regression described associations between increasing year of surgery and complications.Results
Eighty-two CD patients met high-risk criteria (mean age 62.11 ± 10.87 years, 63.7% female, mean BMI 29.70 ± 8.16 kg/m2, and mean CCI 1.07 ± 1.45). The proportion of high-risk patients increased with time, with 41.8% of patients in the early cohort classified as high risk compared with 47.6% of patients in the recent cohort (p > 0.05). Recent high-risk patients were more likely to be female (p = 0.008), have a lower BMI (p = 0.038), and have a higher baseline CCI (p = 0.013). Surgically, high-risk patients in the recent cohort were more likely to undergo low-grade osteotomy (p = 0.003). By postoperative complications, recent high-risk patients were less likely to experience any postoperative adverse events overall (p = 0.020) or complications such as dysphagia (p = 0.045) at 2 years. Regression analysis revealed increasing year of surgery to be correlated with decreasing minor complication rates (p = 0.030), as well as lowered rates of distal junctional kyphosis by 2 years (p = 0.048).Conclusions
Over time, high-risk CD patients have an increase in frequency and comorbidity rates but have demonstrated improved postoperative outcomes. These findings suggest that spine surgeons have improved over time in optimizing selection and reducing potential adverse events in high-risk patients.Item Open Access Assessing Abnormal Proximal Junctional Angles in Adult Spinal Deformity: A Normative Data Approach to Define Proximal Junctional Kyphosis.(Spine, 2024-10) Khalifé, Marc; Lafage, Renaud; Daniels, Alan H; Diebo, Bassel G; Elysée, Jonathan; Ames, Christopher P; Bess, Shay R; Burton, Douglas C; Eastlack, Robert K; Gupta, Munish C; Hostin, Richard A; Kebaish, Khaled; Kim, Han-Jo; Klineberg, Eric O; Mundis, Gregory; Okonkwo, David O; Guigui, Pierre; Ferrero, Emmanuelle; Skalli, Wafa; Assi, Ayman; Vergari, Claudio; Shaffrey, Christopher I; Smith, Justin S; Schwab, Frank J; Lafage, Virginie; ISSGStudy design
Multicentric retrospective study of prospectively collected data.Objective
Based on normative data from a cohort of asymptomatic volunteers, this study sought to determine the rate of abnormal values of proximal junctional angles (PJA) in adult spinal deformity (ASD) surgery patients, and compare it with PJK rate.Summary of background data
Proximal junctional kyphosis (PJK) definition does not take the vertebral level into account.Methods
This study included 721 healthy volunteers and 824 ASD surgery patients with 2-year postoperative follow-up. Normative values for each disc and vertebral body between T1 and T12 were analyzed, then normative values for PJA at each thoracic level were defined in the volunteer cohort as the mean±2 standard deviations. PJA abnormal values at the upper instrumented vertebra (UIV) were compared with Glattes' and Lovecchio's definitions for PJK in the ASD population at two years.Results
Mean age was 37.7±16.3 in the volunteer cohort, with 50.5% of females. Mean thoracic kyphosis (TK) was -50.9±10.8°. Corridors of normality included PJA greater than 20° between T3 and T12. Mean age was 60.5±14.0 years in the ASD cohort, with 77.2% of females. Mean baseline TK was -37.4±19.9°, with a significant increase after surgery (-15.6±15.3°, P<0.001). There was 46.2% of PJK according to Glattes' versus 8.7% according to Lovecchio's and 22.9% of kyphotic PJA compared to normative values (P<0.001).Conclusion
This study provides normative values for segmental and regional alignment of thoracic spine, used to describe abnormal values of PJA for each level. Using level-adjusted PJA values allows a more precise assessment of abnormal proximal angles and question the definition for PJK.Level of evidence
II.Item Open Access Assessment of Adult Spinal Deformity Complication Timing and Impact on 2-Year Outcomes Using a Comprehensive Adult Spinal Deformity Classification System.(Spine, 2022-03) Wick, Joseph B; Le, Hai V; Lafage, Renaud; Gupta, Munish C; Hart, Robert A; Mundis, Gregory M; Bess, Shay; Burton, Douglas C; Ames, Christopher P; Smith, Justin S; Shaffrey, Christopher I; Schwab, Frank J; Passias, Peter G; Protopsaltis, Themistocles S; Lafage, Virginie; Klineberg, Eric O; International Spine Study GroupStudy design
Retrospective review of prospectively collected multicenter registry data.Objective
To identify rates and timing of postoperative complications in adult spinal deformity (ASD) patients, the impact of complication type and timing on health related quality of life (HRQoL) outcomes, and the impact of complication timing on readmission and reoperation rates. Better understanding of complication timing and impact on HRQoL may improve patient selection, preoperative counseling, and postoperative complication surveillance.Summary of background data
ASD is common and associated with significant disability. Surgical correction is often pursued, but is associated with high complication rates. The International Spine Study Group, AO Spinal Deformity Forum, and European Spine Study Group have developed a new complication classification system for ASD (ISSG-AO spine complications classification system).Methods
The ISSG-AO spine complications classification system was utilized to assess complications occurring over the 2-year postoperative time period amongst a multicenter, prospectively enrolled cohort of patients who underwent surgery for ASD. Kaplan-Meier survival curves were established for each complication type. Propensity score matching was performed to adjust for baseline disability and comorbidities. Associations between each complication type and HRQoL, and reoperation/readmission and complication timing, were assessed.Results
Of 584 patients meeting inclusion criteria, cardiopulmonary, gastrointestinal, infection, early adverse events, and operative complications contributed to a rapid initial decrease in complication-free survival. Implant-related, radiographic, and neurologic complications substantially decreased long-term complication-free survival. Only radiographic and implant-related complications were significantly associated with worse 2-year HRQoL outcomes. Need for readmission and/or reoperation was most frequent among those experiencing complications after postoperative day 90.Conclusion
Surgeons should recognize that long-term complications have a substantial negative impact on HRQoL, and should carefully monitor for implant-related and radiographic complications over long-term follow-up.Level of Evidence: 4.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 unsupervised cluster analysis identify patterns of complex adult spinal deformity with distinct perioperative outcomes?(Journal of neurosurgery. Spine, 2023-05) Lafage, Renaud; Fourman, Mitchell S; Smith, Justin S; Bess, Shay; Shaffrey, Christopher I; Kim, Han Jo; Kebaish, Khaled M; Burton, Douglas C; Hostin, Richard; Passias, Peter G; Protopsaltis, Themistocles S; Daniels, Alan H; Klineberg, Eric O; Gupta, Munish C; Kelly, Michael P; Lenke, Lawrence G; Schwab, Frank J; Lafage, Virginie; International Spine Study GroupObjective
The objective of this study was to use an unsupervised cluster approach to identify patterns of operative adult spinal deformity (ASD) and compare the perioperative outcomes of these groups.Methods
A multicenter data set included patients with complex surgical ASD, including those with severe deformities, significant surgical complexity, or advanced age who underwent a multilevel fusion. An unsupervised cluster analysis allowing for 10% outliers was used to identify different deformity patterns. The perioperative outcomes of these clusters were then compared using ANOVA, Kruskal-Wallis, and chi-square tests, with p values < 0.05 considered significant.Results
Two hundred eighty-six patients were classified into four clusters of deformity patterns: hyper-thoracic kyphosis (hyper-TK), severe coronal, severe sagittal, and moderate sagittal. Hyper-TK patients had the lowest disability (mean Oswestry Disability Index [ODI] 32.9 ± 17.1) and pain scores (median numeric rating scale [NRS] back score 6, leg score 1). The severe coronal cluster had moderate functional impairment (mean physical component score 34.4 ± 12.3) and pain (median NRS back score 7, leg score 4) scores. The severe sagittal cluster had the highest levels of disability (mean ODI 49.3 ± 15.6) and low appearance scores (mean 2.3 ± 0.7). The moderate cluster (mean 68.8 ± 7.8 years) had the highest pain interference subscores on the Patient-Reported Outcomes Measurement Information System (mean 65.2 ± 5.8). Overall 30-day adverse events were equivalent among the four groups. Fusion to the pelvis was most common in the moderate sagittal (89.4%) and severe sagittal (97.5%) clusters. The severe coronal cluster had more osteotomies per case (median 11, IQR 6.5-14) and a higher rate of 30-day implant-related complications (5.5%). The severe sagittal and hyper-TK clusters had more three-column osteotomies (43% and 32.3%, respectively). Hyper-TK patients had shorter hospital stays.Conclusions
This cohort of patients with complex ASD surgeries contained four natural clusters of deformity, each with distinct perioperative outcomes.Item Open Access Cervical mismatch: the normative value of T1 slope minus cervical lordosis and its ability to predict ideal cervical lordosis.(Journal of neurosurgery. Spine, 2018-10) Staub, Blake N; Lafage, Renaud; Kim, Han Jo; Shaffrey, Christopher I; Mundis, Gregory M; Hostin, Richard; Burton, Douglas; Lenke, Lawrence; Gupta, Munish C; Ames, Christopher; Klineberg, Eric; Bess, Shay; Schwab, Frank; Lafage, Virginie; International Spine Study GroupOBJECTIVE: Numerous studies have attempted to delineate the normative value for T1S-CL (T1 slope minus cervical lordosis) as a marker for both cervical deformity and a goal for correction similar to how PI-LL (pelvic incidence-lumbar lordosis) mismatch informs decision making in thoracolumbar adult spinal deformity (ASD). The goal of this study was to define the relationship between T1 slope (T1S) and cervical lordosis (CL). METHODS: This is a retrospective review of a prospective database. Surgical ASD cases were initially analyzed. Analysis across the sagittal parameters was performed. Linear regression analysis based on T1S was used to provide a clinically applicable equation to predict CL. Findings were validated using the postoperative alignment of the ASD patients. Further validation was then performed using a second, normative database. The range of normal alignment associated with horizontal gaze was derived from a multilinear regression on data from asymptomatic patients. RESULTS: A total of 103 patients (mean age 54.7 years) were included. Analysis revealed a strong correlation between T1S and C0-7 lordosis (r = 0.886), C2-7 lordosis (r = 0.815), and C0-2 lordosis (r = 0.732). There was no significant correlation between T1S and T1S-CL. Linear regression analysis revealed that T1S-CL assumed a constant value of 16.5° (R2 = 0.664, standard error 2°). These findings were validated on the postoperative imaging (mean absolute error [MAE] 5.9°). The equation was then applied to the normative database (MAE 6.7° controlling for McGregor slope [MGS] between -5° and 15°). A multilinear regression between C2-7, T1S, and MGS demonstrated a range of T1S-CL between 14.5° and 26.5° was necessary to maintain horizontal gaze. CONCLUSIONS: Normative CL can be predicted via the formula CL = T1S - 16.5° ± 2°. This implies a threshold of deformity and aids in providing a goal for surgical correction. Just as pelvic incidence (PI) can be used to determine the ideal LL, T1S can be used to predict ideal CL. This formula also implies that a kyphotic cervical alignment is to be expected for individuals with a T1S < 16.5°.Item Open Access Clinical outcomes and proximal junctional failure in adult spinal deformity patients corrected to normative alignment versus functional alignment.(Journal of neurosurgery. Spine, 2023-07) Protopsaltis, Themistocles S; Ani, Fares; Soroceanu, Alexandra; Lafage, Renaud; Kim, Han Jo; Balouch, Eaman; Norris, Zoe; Smith, Justin S; Daniels, Alan H; Klineberg, Eric O; Ames, Christopher P; Hart, Robert; Bess, Shay; Shaffrey, Christopher I; Schwab, Frank J; Lenke, Lawrence G; Lafage, Virginie; Gupta, Munish CObjective
The objective of this study was to explore the rate of proximal junctional failure (PJF) and functional outcomes of normative alignment goals compared with alignment targets based on age-appropriate physical function.Methods
Baseline relationships between age, pelvic incidence (PI), and a component of the T1 pelvic angle (TPA) within the fusion were analyzed in adult spinal deformity (ASD) patients and compared with those of asymptomatic patients. Linear regression modeling was used to determine alignment based on PI and age in asymptomatic patients (normative alignment), and in ASD patients, alignment corresponding to age-appropriate functional status (functional alignment). A cohort of 288 ASD patients was split into two groups based on whether the patient was closer to their normative or functional alignment goal at their 6-week postoperative radiographic follow-up. The rates of proximal junctional kyphosis (PJK) and PJF were determined for each cohort.Results
In the 288 ASD patients included in this pre- to postoperative analysis, there was no difference in baseline alignment or health-related quality of life (HRQOL) between the normative alignment and functional alignment groups. At 6 weeks, patients with normative alignment had a smaller TPA (4.45° vs 14.1°) and PI minus lumbar lordosis (-7.24° vs 7.4°) (both p < 0.0001) and higher PJK (40% vs 27.2%, p = 0.03) and PJF (17% vs 6.8%, p = 0.008) rates than patients with functional alignment.Conclusions
Correction in ASD patients to normative alignment resulted in higher rates of PJK and PJF without improvements in HRQOL. Correction in ASD patients to functional alignment that mirrors the physical function of their age-matched asymptomatic peers is recommended.Item Open Access Comparing and Contrasting the Clinical Utility of Sagittal Spine Alignment Classification Frameworks: Roussouly Versus SRS-Schwab.(Spine, 2022-03) Passias, Peter G; Bortz, Cole; Pierce, Katherine E; Passfall, Lara; Kummer, Nicholas A; Krol, Oscar; Lafage, Renaud; Diebo, Bassel G; Lafage, Virginie; Ames, Christopher P; Burton, Douglas C; Gupta, Munish C; Sciubba, Daniel M; Schoenfeld, Andrew J; Bess, Shay; Hostin, Richard; Shaffrey, Christopher I; Line, Breton G; Klineberg, Eric O; Smith, Justin S; Schwab, Frank J; International Spine Study GroupStudy design
Retrospective cohort study of a prospectively collected database.Objective
To compare clinical utility of two common classification systems for adult spinal deformity (ASD) and determine whether both should be considered in surgical planning to improve patient outcomes.Summary of background data
Surgical restoration of appropriate Roussouly classification shape or SRS-Schwab ASD classification may improve outcomes.Methods
ASD patients with pre- and 2-year postop (2Y) radiographic/health-related quality of life (HRQL) data were grouped by "theoretical" and "current" Roussouly type. Univariate analyses assessed outcomes of patients who mismatched Roussouly types at both pre- and 2Y intervals (Mismatched) and those of preoperative mismatched patients who matched at 2-years (Matched). Subanalysis assessed outcomes of patients who improved in Schwab modifiers, and patients who both improved in both Schwab modifiers and matched Roussouly type by 2Y.Results
Included: 515 ASD patients (59 ± 14 yrs, 80% F). Preoperative breakdown of "current" Roussouly types: Type 1 (10%), 2 (54%), 3 (24%), and 4 (12%). Matched and Mismatched groups did not differ in rates of reaching MCID for any HRQL metrics by 2Y (all P > 0.10). Reoperation, PJK, and complications did not differ between Matched and Mismatched (all P > 0.10), but Roussouly Matched patients had toward lower rates of instrumentation failure (17.2% vs. 24.8%, P = 0.038). By 2Y, 28% of patients improved in PT Schwab modifier, 37% in SVA, and 46% in PI-LL. Patients who both Matched Roussouly at 2Y and improved in all Schwab modifiers met MCID for Oswestry Disability Index (ODI) and Scoliosis Research Society (SRS) activity at higher rates than patients who did not.Conclusion
Isolated restoration per the Roussouly system was not associated with superior outcomes. Patients who both matched Roussouly type and improved in Schwab modifiers had superior patient-reported outcomes at 2-years. Concurrent consideration of both systems may offer utility in establishing optimal realignment goals.Level of Evidence: 3.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 Complications and intercenter variability of three-column osteotomies for spinal deformity surgery: a retrospective review of 423 patients.(Neurosurgical focus, 2014-05) Bianco, Kristina; Norton, Robert; Schwab, Frank; Smith, Justin S; Klineberg, Eric; Obeid, Ibrahim; Mundis, Gregory; Shaffrey, Christopher I; Kebaish, Khaled; Hostin, Richard; Hart, Robert; Gupta, Munish C; Burton, Douglas; Ames, Christopher; Boachie-Adjei, Oheneba; Protopsaltis, Themistocles S; Lafage, Virginie; International Spine Study GroupObject
Three-column resection osteotomies (3COs) are commonly performed for sagittal deformity but have high rates of reported complications. Authors of this study aimed to examine the incidence of and intercenter variability in major intraoperative complications (IOCs), major postoperative complications (POCs) up to 6 weeks postsurgery, and overall complications (that is, both IOCs and POCs). They also aimed to investigate the incidence of and intercenter variability in blood loss during 3CO procedures.Methods
The incidence of IOCs, POCs, and overall complications associated with 3COs were retrospectively determined for the study population and for each of 8 participating surgical centers. The incidence of major blood loss (MBL) over 4 L and the percentage of total blood volume lost were also determined for the study population and each surgical center. Complication rates and blood loss were compared between patients with one and those with two osteotomies, as well as between patients with one thoracic osteotomy (ThO) and those with one lumbar or sacral osteotomy (LSO). Risk factors for developing complications were determined.Results
Retrospective review of prospectively acquired data for 423 consecutive patients who had undergone 3CO at 8 surgical centers was performed. The incidence of major IOCs, POCs, and overall complications was 7%, 39%, and 42%, respectively, for the study population overall. The most common IOC was spinal cord deficit (2.6%) and the most common POC was unplanned return to the operating room (19.4%). Patients with two osteotomies had more POCs (56% vs 38%, p = 0.04) than the patients with one osteotomy. Those with ThO had more IOCs (16% vs 6%, p = 0.03), POCs (58% vs 34%, p < 0.01), and overall complications (67% vs 37%, p < 0.01) than the patients with LSO. There was significant variation in the incidence of IOCs, POCs, and overall complications among the 8 sites (p < 0.01). The incidence of MBL was 24% for the study population, which varied significantly between sites (p < 0.01). Patients with MBL had a higher risk of IOCs, POCs, and overall complications (OR 2.15, 1.76, and 2.01, respectively). The average percentage of total blood volume lost was 55% for the study population, which also varied among sites (p < 0.01).Conclusions
Given the complexity of 3COs for spinal deformity, it is important for spine surgeons to understand the risk factors and complication rates associated with these procedures. In this study, the overall incidence of major complications following 3CO procedures was 42%. Risks for developing complications included an older age (> 60 years), two osteotomies, ThO, and MBL.Item Open Access Contemporary utilization of three-column osteotomy techniques in a prospective complex spinal deformity multicenter database: implications on full-body alignment and perioperative course.(Spine deformity, 2024-06) Williamson, Tyler K; Mir, Jamshaid M; Smith, Justin S; Lafage, Virginie; Lafage, Renaud; Line, Breton; Diebo, Bassel G; Daniels, Alan H; Gum, Jeffrey L; Hamilton, D Kojo; Scheer, Justin K; Eastlack, Robert; Demetriades, Andreas K; Kebaish, Khaled M; Lewis, Stephen; Lenke, Lawrence G; Hostin, Richard A; Gupta, Munish C; Kim, Han Jo; Ames, Christopher P; Burton, Douglas C; Shaffrey, Christopher I; Klineberg, Eric O; Bess, Shay; Passias, Peter G; International Spine Study GroupBackground
Research has focused on the increased correction from a three-column osteotomy (3CO) during adult spinal deformity (ASD) surgery. However, an in-depth analysis on the performance of a 3CO in a cohort of complex spinal deformity cases has not been described.Study design/setting
This is a retrospective study on a prospectively enrolled, complex ASD database.Purpose
This study aimed to determine if three-column osteotomies demonstrate superior benefit in correction of complex sagittal deformity at the cost of increased perioperative complications.Methods
Surgical complex adult spinal deformity patients were included and grouped into thoracolumbar 3COs compared to those who did not have a 3CO (No 3CO) (remaining cohort). Rigid deformity was defined as ΔLL less than 33% from standing to supine. Severe deformity was defined as global (SVA > 70 mm) or C7-PL > 70 mm, or lumbopelvic (PI-LL > 30°). Means comparison tests assessed correction by 3CO grade/location. Multivariate analysis controlling for baseline deformity evaluated outcomes up to six weeks compared to No 3CO.Results
648 patients were included (Mean age 61 ± 14.6 years, BMI 27.55 ± 5.8 kg/m2, levels fused: 12.6 ± 3.8). 126 underwent 3CO, a 20% higher usage than historical cohorts. 3COs were older, frail, and more likely to undergo revision (OR 5.2, 95% CI [2.6-10.6]; p < .001). 3COs were more likely to present with both severe global/lumbopelvic deformity (OR 4), 62.4% being rigid. 3COs had greater use of secondary rods (OR 4st) and incurred 4 times greater risk for: massive blood loss (> 3500 mL), longer LOS, SICU admission, perioperative wound and spine-related complications, and neurologic complications when performed below L3. 3COs had similar HRQL benefit, but higher perioperative opioid use. Mean segmental correction increased by grade (G3-21; G4-24; G5-27) and was 4 × greater than low-grade osteotomies, especially below L3 (OR 12). 3COs achieved 2 × greater spinopelvic correction. Higher grades properly distributed lordosis 50% of the time except L5. Pelvic compensation and non-response were relieved more often with increasing grade, with greater correction in all lower extremity parameters (p < .01). Due to the increased rate of complications, 3COs trended toward higher perioperative cost ($42,806 vs. $40,046, p = .086).Conclusion
Three-column osteotomy usage in contemporary complex spinal deformities is generally limited to more disabled individuals undergoing the most severe sagittal and coronal realignment procedures. While there is an increased perioperative cost and prolongation of length of stay with usage, these techniques represent the most powerful realignment techniques available with a dramatic impact on normalization at operative levels and reciprocal changes.Item Open Access Cost Benefit of Implementation of Risk Stratification Models for Adult Spinal Deformity Surgery.(Global Spine J, 2023-12-11) Passias, Peter G; Williamson, Tyler K; Kummer, Nicholas A; Pellisé, Ferran; Lafage, Virginie; Lafage, Renaud; Serra-Burriel, Miguel; Smith, Justin S; Line, Breton; Vira, Shaleen; Gum, Jeffrey L; Haddad, Sleiman; Sánchez Pérez-Grueso, Francisco Javier; Schoenfeld, Andrew J; Daniels, Alan H; Chou, Dean; Klineberg, Eric O; Gupta, Munish C; Kebaish, Khaled M; Kelly, Michael P; Hart, Robert A; Burton, Douglas C; Kleinstück, Frank; Obeid, Ibrahim; Shaffrey, Christopher I; Alanay, Ahmet; Ames, Christopher P; Schwab, Frank J; Hostin, Richard A; Bess, Shay; International Spine Study GroupSTUDY DESIGN/SETTING: Retrospective cohort study. OBJECTIVE: Assess the extent to which defined risk factors of adverse events are drivers of cost-utility in spinal deformity (ASD) surgery. METHODS: ASD patients with 2-year (2Y) data were included. Tertiles were used to define high degrees of frailty, sagittal deformity, blood loss, and surgical time. Cost was calculated using the Pearl Diver registry and cost-utility at 2Y was compared between cohorts based on the number of risk factors present. Statistically significant differences in cost-utility by number of baseline risk factors were determined using ANOVA, followed by a generalized linear model, adjusting for clinical site and surgeon, to assess the effects of increasing risk score on overall cost-utility. RESULTS: By 2 years, 31% experienced a major complication and 23% underwent reoperation. Patients with ≤2 risk factors had significantly less major complications. Patients with 2 risk factors improved the most from baseline to 2Y in ODI. Average cost increased by $8234 per risk factor (R2 = .981). Cost-per-QALY at 2Y increased by $122,650 per risk factor (R2 = .794). Adjusted generalized linear model demonstrated a significant trend between increasing risk score and increasing cost-utility (r2 = .408, P < .001). CONCLUSIONS: The number of defined patient-specific and surgical risk factors, especially those with greater than two, were associated with increased index surgical costs and diminished cost-utility. Efforts to optimize patient physiology and minimize surgical risk would likely reduce healthcare expenditures and improve the overall cost-utility profile for ASD interventions.Level of evidence: III.Item Open Access Determining the best vertebra for measuring pelvic incidence and spinopelvic parameters in adult spinal deformity patients with transitional anatomy.(Journal of neurosurgery. Spine, 2023-10) Ani, Fares; Protopsaltis, Themistocles S; Parekh, Yesha; Odeh, Khalid; Lafage, Renaud; Smith, Justin S; Eastlack, Robert K; Lenke, Lawrence; Schwab, Frank; Mundis, Gregory M; Gupta, Munish C; Klineberg, Eric O; Lafage, Virginie; Hart, Robert; Burton, Douglas; Ames, Christopher P; Shaffrey, Christopher I; Bess, ShayObjective
The aim of this study was to determine if spinal deformity patients with L5 sacralization should have pelvic incidence (PI) and other spinopelvic parameters measured from the L5 or S1 endplate.Methods
This study was a multicenter retrospective comparative cohort study comprising a large database of adult spinal deformity (ASD) patients and a database of asymptomatic individuals. Linear regression modeling was used to determine normative T1 pelvic angle (TPA) and PI - lumbar lordosis (LL) mismatch (PI-LL) based on PI and age in a database of asymptomatic subjects. In an ASD database, patients with radiographic evidence of L5 sacralization had the PI, LL, and TPA measured from the superior endplate of S1 and then also from L5. The differences in TPA and PI-LL from normative were calculated in the sacralization cohort relative to L5 and S1 and correlated to the Oswestry Disability Index (ODI). Patients were grouped based on the Scoliosis Research Society (SRS)-Schwab PI-LL modifier (0, +, or ++) using the L5 PI-LL and S1 PI-LL. Baseline ODI and SF-36 Physical Component Summary (PCS) scores were compared across and within groups.Results
Among 1179 ASD patients, 276 (23.4%) had transitional anatomy, 176 with sacralized L5 (14.9%) and 100 (8.48%) with lumbarization of S1. The 176 patients with sacralized L5 were analyzed. When measured using the L5 superior endplate, pelvic parameters were significantly smaller than those measured relative to S1 (PI: 24.5° ± 11.0° vs 55.7° ± 12.0°, p = 0.001;TPA: 11.2° ± 12.0° vs 20.3° ± 12.5°, p = 0.001; and PI-LL: 0.67° ± 21.1° vs 11.4° ± 20.8°, p = 0.001). When measured from S1, 76 (43%), 45 (25.6%), and 55 (31.3%) patients had SRS-Schwab PI-LL modifiers of 0, +, and ++, respectively, compared with 124 (70.5%), 22 (12.5%), and 30 (17.0%), respectively, when measured from L5. There were significant differences in ODI and PCS scores as the SRS-Schwab grade increased regardless of L5 or S1 measurement. The L5 group had lower PCS functional scores for SRS-Schwab modifiers 0 and ++ relative to same grades in the S1 group. Offset from normative TPA (0.5° ± 11.1° vs 9.6° ± 10.8°, p = 0.001) and PI-LL (4.5° ± 20.4° vs 15.2° ± 19.3°, p = 0.001) were smaller when measuring from L5. Moreover, S1 measurements were more correlated with health status by ODI (TPA offset from normative: S1, R = 0.326 vs L5, R = 0.285; PI-LL offset from normative: S1, R = 0.318 vs L5, R = 0.274).Conclusions
Measuring the PI and spinopelvic parameters at L5 in sacralized anatomy results in underestimating spinal deformity and is less correlated with health-related quality of life. Surgeons may consider measuring PI and spinopelvic parameters relative to S1 rather than at L5 in patients with a sacralized L5.Item Open Access Distal junctional kyphosis in adult cervical deformity patients: where does it occur?(European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 2023-05) Ye, Jichao; Rider, Sean M; Lafage, Renaud; Gupta, Sachin; Farooqi, Ali S; Protopsaltis, Themistocles S; Passias, Peter G; Smith, Justin S; Lafage, Virginie; Kim, Han-Jo; Klineberg, Eric O; Kebaish, Khaled M; Scheer, Justin K; Mundis, Gregory M; Soroceanu, Alex; Bess, Shay; Ames, Christopher P; Shaffrey, Christopher I; Gupta, Munish C; International Spine Study Group (ISSG)Purpose
To evaluate the impact of the lowest instrumented vertebra (LIV) on Distal Junctional kyphosis (DJK) incidence in adult cervical deformity (ACD) surgery.Methods
Prospectively collected data from ACD patients undergoing posterior or anterior-posterior reconstruction at 13 US sites was reviewed up to 2-years postoperatively (n = 140). Data was stratified into five groups by level of LIV: C6-C7, T1-T2, T3-Apex, Apex-T10, and T11-L2. DJK was defined as a kyphotic increase > 10° in Cobb angle from LIV to LIV-1. Analysis included DJK-free survival, covariate-controlled cox regression, and DJK incidence at 1-year follow-up.Results
25/27 cases of DJK developed within 1-year post-op. In patients with a minimum follow-up of 1-year (n = 102), the incidence of DJK by level of LIV was: C6-7 (3/12, 25.00%), T1-T2 (3/29, 10.34%), T3-Apex (7/41, 17.07%), Apex-T10 (8/11, 72.73%), and T11-L2 (4/8, 50.00%) (p < 0.001). DJK incidence was significantly lower in the T1-T2 LIV group (adjusted residual = -2.13), and significantly higher in the Apex-T10 LIV group (adjusted residual = 3.91). In covariate-controlled regression using the T11-L2 LIV group as reference, LIV selected at the T1-T2 level (HR = 0.054, p = 0.008) or T3-Apex level (HR = 0.081, p = 0.010) was associated with significantly lower risk of DJK. However, there was no difference in DJK risk when LIV was selected at the C6-C7 level (HR = 0.239, p = 0.214).Conclusion
DJK risk is lower when the LIV is at the upper thoracic segment than the lower cervical segment. DJK incidence is highest with LIV level in the lower thoracic or thoracolumbar junction.