Browsing by Author "Diebo, BG"
Now showing 1 - 11 of 11
- Results Per Page
- Sort Options
Item Open Access Clinically Significant Thromboembolic Disease in Adult Spinal Deformity Surgery: Incidence and Risk Factors in 737 Patients(Global Spine Journal, 2018-05-01) Kim, HJ; Iyer, S; Diebo, BG; Kelly, MP; Sciubba, D; Schwab, F; Lafage, V; Mundis, GM; Shaffrey, CI; Smith, JS; Hart, R; Burton, D; Bess, S; Klineberg, EOStudy Design: Retrospective cohort study. Objectives: Describe the rate and risk factors for venous thromboembolic events (VTEs; defined as deep venous thrombosis [DVT] and/or pulmonary embolism [PE]) in adult spinal deformity (ASD) surgery. Methods: ASD patients with VTE were identified in a prospective, multicenter database. Complications, revision, and mortality rate were examined. Patient demographics, operative details, and radiographic and clinical outcomes were compared with a non-VTE group. Multivariate binary regression model was used to identify predictors of VTE. Results: A total of 737 patients were identified, 32 (4.3%) had VTE (DVT = 14; PE = 18). At baseline, VTE patients were less likely to be employed in jobs requiring physical labor (59.4% vs 79.7%, P <.01) and more likely to have osteoporosis (29% vs 15.1%, P =.037) and liver disease (6.5% vs 1.4%, P =.027). Patients with VTE had a larger preoperative sagittal vertical axis (SVA; 93 mm vs 55 mm, P <.01) and underwent larger SVA corrections. VTE was associated with a combined anterior/posterior approach (45% vs 25%, P =.028). VTE patients had a longer hospital stay (10 vs 7 days, P <.05) and higher mortality rate (6.3% vs 0.7%, P <.01). Multivariate analysis demonstrated osteoporosis, lack of physical labor, and increased SVA correction were independent predictors of VTE (r2 =.11, area under the curve = 0.74, P <.05). Conclusions: The incidence of VTE in ASD is 4.3% with a DVT rate of 1.9% and PE rate of 2.4%. Osteoporosis, lack of physical labor, and increased SVA correction were independent predictors of VTE. Patients with VTE had a higher mortality rate compared with non-VTE patients.Item Open Access Impact of obesity on complications, infection, and patient-reported outcomes in adult spinal deformity surgery(Journal of Neurosurgery: Spine, 2015-11-01) Soroceanu, A; Burton, DC; Diebo, BG; Smith, JS; Hostin, R; Shaffrey, CI; Boachie-Adjei, O; Mundis, GM; Ames, C; Errico, TJ; Bess, S; Gupta, MC; Hart, RA; Schwab, FJ; Lafage, VOBJECT: Adult spinal deformity (ASD) surgery is known for its high complication rate. This study examined the impact of obesity on complication rates, infection, and patient-reported outcomes in patients undergoing surgery for ASD. METHODS: This study was a retrospective review of a multicenter prospective database of patients with ASD who were treated surgically. Patients with available 2-year follow-up data were included. Obesity was defined as having a body mass index (BMI) ≥ 30 kg/m2. Data collected included complications (total, minor, major, implant-related, radiographic, infection, revision surgery, and neurological injury), estimated blood loss (EBL), operating room (OR) time, length of stay (LOS), and patient-reported questionnaires (Oswestry Disability Index [ODI], Short Form-36 [SF-36], and Scoliosis Research Society [SRS]) at baseline and at 6 weeks, 1 year, and 2 years postoperatively. The impact of obesity was studied using multivariate modeling, accounting for confounders. RESULTS: Of 241 patients who satisfied inclusion criteria, 175 patients were nonobese and 66 were obese. Regression models showed that obese patients had a higher overall incidence of major complications (IRR 1.54, p = 0.02) and wound infections (odds ratio 4.88, p = 0.02). Obesity did not increase the number of minor complications (p = 0.62), radiographic complications (p = 0.62), neurological complications (p = 0.861), or need for revision surgery (p = 0.846). Obesity was not significantly correlated with OR time (p = 0.23), LOS (p = 0.9), or EBL (p = 0.98). Both groups experienced significant improvement over time, as measured on the ODI (p = 0.0001), SF-36 (p = 0.0001), and SRS (p = 0.0001) questionnaires. However, the overall magnitude of improvement was less for obese patients (ODI, p = 0.0035; SF-36, p = 0.0012; SRS, p = 0.022). Obese patients also had a lower rate of improvement over time (SRS, p = 0.0085; ODI, p = 0.0001; SF-36, p = 0.0001). CONCLUSIONS: This study revealed that obese patients have an increased risk of complications following ASD correction. Despite these increased complications, obese patients do benefit from surgical intervention; however, their improvement in health-related quality of life (HRQL) is less than that of nonobese patients.Item Open Access Longitudinal Assessment of Modern Spine Surgery Training: 10-Year Follow-up of a Nationwide Survey of Residency and Spine Fellowship Program Directors(JBJS Open Access, 2023-08-01) Daniels, AH; Alsoof, D; McDonald, CL; Zhang, AS; Diebo, BG; Eberson, CP; Kuris, EO; Lavelle, W; Ames, CP; Shaffrey, CI; Hart, RABackground:Spine surgeons complete training through residency in orthopaedic surgery (ORTH) or neurosurgery (NSGY). A survey was conducted in 2013 to evaluate spine surgery training. Over the past decade, advances in surgical techniques and the changing dynamics in fellowship training may have affected training and program director (PD) perceptions may have shifted.Methods:This study is a cross-sectional survey distributed to all PDs of ORTH and NSGY residencies and spine fellowships in the United States. Participants were queried regarding characteristics of their program, ideal characteristics of residency training, and opinions regarding the current training environment. χ2tests were used to compare answers over the years.Results:In total, 241 PDs completed the survey. From 2013 to 2023, NSGY increased the proportion of residents with >300 spine cases (86%-100%) while ORTH remained with >90% of residents with < 225 cases (p < 0.05). A greater number of NSGY PDs encouraged spine fellowship even for community spine surgery practice (0% in 2013 vs. 14% in 2023, p < 0.05), which continued to be significantly different from ORTH PDs (∼88% agreed, p > 0.05). 100% of NSGY PDs remained confident in their residents performing spine surgery, whereas ORTH confidence significantly decreased from 43% in 2013 to 25% in 2023 (p < 0.05). For spinal deformity, orthopaedic PDs (92%), NSGY PDs (96%), and fellowship directors (95%), all agreed that a spine fellowship should be pursued (p = 0.99). In both 2013 and 2023, approximately 44% were satisfied with the spine training model in the United States. In 2013, 24% of all PDs believed we should have a dedicated spine residency, which increased to 39% in 2023 (fellowship: 57%, ORTH: 38%, NSGY: 21%) (p < 0.05).Conclusion:Spine surgery training continues to evolve, yet ORTH and neurological surgery training remains significantly different in case volumes and educational strengths. In both 2013 and 2023, less than 50% of PDs were satisfied with the current spine surgery training model, and a growing minority believe that spine surgery should have its own residency training pathway.Level of Evidence:IV.Item Open Access Proximal junctional kyphosis and failure: How much can we attribute to known risk factors?(Spine Journal, 2024-09-01) Onafowokan, O; Jankowski, PP; Mir, J; Das, A; Hockley, A; Lorentz, N; Galetta, MS; Lebovic, J; Hamilton, DK; Diebo, BG; Daniels, AH; Anand, N; Pour, PT; Sciubba, DM; Ramos, RDLG; Shaffrey, CI; Lafage, R; Lafage, V; Schoenfeld, AJ; Passias, PGBACKGROUND CONTEXT: Despite advancements in the understanding of spinal alignment and in instrumentation for adult spine deformity (ASD) surgery, complications such as proximal junctional kyphosis and proximal junctional failure (PJK/PJF) continue to be a significant concern. PURPOSE: To assess the attributable risk of various reported contributors to development of PJK/PJF. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: A total of 464 ASD patients. OUTCOME MEASURES: Odds ratios of PJK/F risk factors. METHODS: We included ASD patients with complete baseline (BL) and up to 2Y clinical, radiographic and HRQL data. Stratified according to development of PJK/PJF by 2 years. Means comparison analyses compared outcomes between groups. Backstep logistic regression assessed factors predictive of PJK/F development. RESULTS: There were 464 patients included (age: 59.8 ± 14.3 years, BMI: 26.9 ± 5.5 kg/m2, CCI: 1.65 ± 1.68). 80.5% of patients were female; 173 patients (37.3%) formed the PJK/F+ group, as at 2 years (173 PJK and 28 PJF patients). At BL, PJK/F+ patients were older (63.2 vs 57.9 years, p<0.001) and had worse deformity (PI-LL 20.3 vs 11.8, p<0.001). There were no differences between groups in baseline disability, demographic, frailty or comorbidity factors. Controlling for age and baseline deformity, PJK/F+ patients were more likely to develop mechanical complications (OR 2.1, 95% CI: 1.2-3.7, p=0.007). Use of PJK prophylaxis techniques did not have a significant effect on risk of developing PJK/F (p=0.307). Factors associated with increased risk of developing PJK/F were significant baseline deformity (OR 1.02, 95% CI: 1.01-1.03, p=0.026), peripheral vascular disease (OR 5.5, 1.3-23.6, p=0.023), undergoing an osteotomy (OR 1.7, 1.1-2.8, p=0.017) and age >60 (OR 1.1, 1.1-1.2, p=0.026) and hypertension (OR 2.01, 1.04-3.87, p=0.038). Diabetes was associated with lower odds for developing PJK/F+ (OR: 0.3, 95% CI: 0.1-0.8, p=0.018). CONCLUSIONS: Proximal junctional kyphosis/failure remains a significant postoperative concern in the ASD population. With currently known risk factors, we are still unable to fully quantify and predict a patient's total risk for developing postoperative PJK/F. Further work is needed to delineate contributing factors that are yet to be determined. FDA Device/Drug Status: This abstract does not discuss or include any applicable devices or drugs.Item Open Access Quantifying the importance of upper cervical extension reserve in adult cervical deformity surgery and its impact on baseline presentation and outcomes(Spine Journal, 2024-09-01) Passias, PG; Mir, J; Smith, JS; Lafage, V; Lafage, R; Diebo, BG; Daniels, AH; Onafowokan, O; Line, B; Eastlack, RK; Mundis, GM; Kebaish, KM; Soroceanu, A; Scheer, JK; Kelly, MP; Protopsaltis, TS; Kim, HJ; Hostin, RA; Gupta, MC; Riew, KD; Burton, DC; Schwab, FJ; Bess, S; Shaffrey, CI; Ames, CPBACKGROUND CONTEXT: Hyperextension of the upper cervical spine is a prominent compensatory mechanism to maintain horizontal gaze and balance in adult cervical deformity (ACD) patients, akin to pelvic tilt in spinal deformity. The relaxation of ER and its impact on postoperative outcomes is not well understood. PURPOSE: To evaluate upper cervical ER impact on postoperative disability and outcomes. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: Adult cervical deformity. OUTCOME MEASURES: ER, HRQLs. METHODS: ACD patients undergoing subaxial cervical fusion with 2Y data were included. Upper cervical extension reserve (ER) was defined as: C0-C2 sagittal Cobb angle between neutral and extension. Relaxation of ER was defined as the ER normative mean in those that met the ideal in all Passias ACD modifiers. Outcomes were defined as "good" if meeting ≥2 of the three: (1) NDI <20 or meeting MCID, (2) mild myelopathy (mJOA≥14), and (3) NRS-Neck ≤5 or improved by ≥2 points from baseline. Controlled analysis was conducted with ANCOVA and multivariable logistic regressions. Conditional inference tree (CIT) analysis determined thresholds. RESULTS: A total of 108 ACD patients met inclusion. (Age 61.4 ± 12.3, 61% F, BMI 29.4 ± 7.5 kg/m2, mCD-FI .24 ±.12, CCI 0.97 ± 1.30). Radiographic alignment is depicted in Table 1. Preoperative C0-C2 ER was 8.7 ±9.0 ±, and at the last follow-up was 10.3 ± 11.1. ER in those meeting all ideal CD modifiers at 2Y was 12.9 ± 9.0. Preoperatively 29% had adequate ER, while 59.7% had improvement in ER postoperatively, with 50% of patients achieving adequate ER at 2Y. Higher ER significantly correlated with lower cervical deformity (p<.05). Preoperatively, greater ER was predictive of lower preoperative disability, with worse baseline mobility, pain, and anxiety (EQ5D) (B = -6.1, -2.9, -2.9 respectively; R2 =0.212, p<.001). Improvement of ER depicted a higher rate of MCID for NDI (64% vs 39%, p=.008), and meeting good clinical outcomes (72% vs 54%, p=.04). Controlling for baseline deformity and demographic factors found resolution of inadequate ER to have 7x higher likelihood of meeting MCID for NDI (6.941 [1.378-34.961], p=.019) and 4x higher odds of achieving good outcomes (4.022 [1.017-15.900], p=.047). Isolating those with inadequate preoperative ER, found postoperative resolution having 5x odds of good outcomes (p<.05). In those with inadequate ER at baseline, the preoperative C2-C7 of <-18 and TS-CL of >59 for TS-CL was predictive of ER resolution (p<.05). In those with preoperative C2-C7 >-18, a T1PA of >13 was predictive of postoperative return of ER (p<.05). Independently TS-CL of >59, was significant for predicting ER return postoperatively, highlighting its compensatory role for proximal spinal deformities (all p<.05). Surgical correction of C2-C7 by >16 from baseline was found to be predictive of ER return. CONCLUSIONS: Increased preoperative utilization of the extension reserve in the upper cervical spine in cervical deformity was associated with worse baseline regional and global alignment while impacting health-related measures. The majority of patients had relaxation of extension reserve postoperatively, however, in those who didn't, there was a decreased likelihood of achieving good outcomes. FDA Device/Drug Status: This abstract does not discuss or include any applicable devices or drugs.Item Open Access Redefining Clinically Significant Blood Loss in Complex Adult Spine Deformity Surgery(Spine, 2024-01-01) Daher, M; Xu, A; Singh, M; Lafage, R; Line, BG; Lenke, LG; Ames, CP; Burton, DC; Lewis, SM; Eastlack, RK; Gupta, MC; Mundis, GM; Gum, JL; Hamilton, KD; Hostin, R; Lafage, V; Passias, PG; Protopsaltis, TS; Kebaish, KM; Schwab, FJ; Shaffrey, CI; Smith, JS; Bess, S; Klineberg, EO; Diebo, BG; Daniels, AHStudy Design. Retrospective analysis of prospectively-collected data Objective. This study aims to define clinically relevant blood loss in adult spinal deformity (ASD) surgery. Background. Current definitions of excessive blood loss following spine surgery are highly variable and may be suboptimal in predicting adverse events (AE). Methods. Adults undergoing complex ASD surgery were included. Estimated blood loss (EBL) was extracted for investigation, and estimated blood volume loss (EBVL) was calculated by dividing EBL by the preoperative blood volume utilizing Nadler's formula. LASSO regression was performed to identify five variables from demographic and peri-operative parameters. Logistic regression was subsequently performed to generate a receiver operating characteristics (ROC) curve and estimate an optimal threshold for EBL and EBVL. Finally, the proportion of patients with AE plotted against EBL and EBVL to confirm the identified thresholds. Results. In total 552 patients were included with a mean age of 60.7±15.1 years, 68% females, mean CCI was 1.0±1.6, and 22% experienced AEs. LASSO regression identified ASA score, baseline hypertension, preoperative albumin, and use of intra-operative crystalloids as the top predictors of an AE, in addition to EBL/EBVL. Logistic regression resulted in ROC curve which was used to identify a cut-off of 2.3 liters of EBL and 42% for EBVL. Patients exceeding these thresholds had AE rates of 36% (odds-ratio: 2.1, 95% CI [1.2-3.6]) and 31% (odds-ratio: 1.7, 95% CI [1.1-2.8]), compared to 21% for those below the thresholds of EBL and EBVL, respectively. Conclusion. In complex ASD surgery, intraoperative EBL of 2.3 liters and an EBVL of 42% are associated with clinically-significant AEs. These thresholds may be useful in guiding preoperative-patient-counseling, healthcare system quality initiatives, and clinical perioperative bloodloss management strategies in patients undergoing complex spine surgery. Additionally, similar methodology could be performed in other specialties to establish procedure-specific clinically-relevant bloodloss thresholds.Item Open Access Severe hip and knee osteoarthritis worsens patient-reported disability in adult spinal deformity patients(Spine Journal, 2024-09-01) Balmaceno-Criss, M; Singh, M; Xu, A; Daher, M; Lafage, R; Lewis, SJ; Klineberg, EO; Eastlack, RK; Gupta, MC; Mundis, GM; Gum, JL; Hamilton, DK; Hostin, RA; Passias, PG; Protopsaltis, TS; Kebaish, KM; Kim, HJ; Shaffrey, CI; Smith, JS; Line, B; Lenke, LG; Ames, CP; Burton, DC; Bess, S; Schwab, FJ; Lafage, V; Diebo, BG; Daniels, AHBACKGROUND CONTEXT: The complex interplay between lower extremity osteoarthritis and sagittal alignment in adult spinal deformity patients is of growing clinical interest. PURPOSE: To quantify the sequential effects of lower extremity OA on PROMs in ASD patients. STUDY DESIGN/SETTING: Retrospective review of prospectively collected data. PATIENT SAMPLE: ASD patients with no prior history of thoracolumbar surgery, and available baseline PROMs and standing radiographs were included. OUTCOME MEASURES: Baseline demographics, spinopelvic alignment, and PROMs. METHODS: Included patients with PROMs, standing xrays, no prior thoracolumbar surgery, and bilateral Kellgren-Lawrence (KL) hip/knee grade at baseline. Patients grouped into Spine (KL <3 BL hips & knees), Spine-Hip (KL>3 BL hips, KL <3 BL knees), Spine-Knee (KL>3 BL knees, KL>3 BL hips), Spine-Hip-Knee (KL>3 BL hips & knees). Baseline demographics, spinopelvic alignment, and PROMs were compared. Multivariate regression with forward stepwise selection predicted PROMs with variables (demographic, radiographic, OA severity) with significant association identified on Pearson correlation RESULTS: Included 160 patients: 56 Spine, 32 Spine-Knee, 20 Spine-Hip, and 52 Spine-Hip-Knee. Spine-Hip-Knee patients were older (Spine=62.2, Spine-Knee=61.2, Spine-Hip=59.1, Spine-Hip-Knee=68.5; p<.001) but similar in sex, comorbidities, and frailty; p>.05. Spine-Hip-Knee patients had higher SVA (50.0,30.6,60.5,83.5), T1PA (25.2,20.4,20.3,27.8), GSA (3.7,2.3,4.3,7.5), and KA (0.0,2.1,2.9,10.5); p<.005. SRS total and VR12 PCS scores were similar but VR12-2b climbing stairs (1.73,1.91,1.55,1.40, p=.014) and SRS-8 back pain at rest (2.29,2.84,1.95,2.71, p=.012) were lower in Spine-Hip-Knee and Spine-Hip, respectively. ODI (42.75,35.88,50.30,44.59, p=.040) and ODI Pain (2.88,1.84,2.90,2.46, p=0.019) were higher in Spine-Hip patients; ODI lifting was higher in hip OA patients but not significant (2.95,2.69,3.45,3.35, p>.05). In multivariate analyses, KOA changed the prediction of ODI pain from R2 0.052 to 0.086 and SRS-8 from R2 0.077 to 0.147. HOA changed the prediction of VR12-2b from R2 0.113 to 0.140 and ODI Lifting from R2 0.175 to 0.202. Frailty impacted PROMs across all models (p<.001) and GSA changed ODI, ODI pain, and VR12-2b models (p<.05). CONCLUSIONS: Severe hip and knee OA worsen patient-reported disability and physical function in ASD patients. These results quantify the impact of lower limb arthritis on patient reported outcomes, and highlight the need for integrated assessment and management of both spinal alignment and joint health in patients. FDA Device/Drug Status: This abstract does not discuss or include any applicable devices or drugs.Item Open Access Should pelvic incidence influence realignment strategy? A detailed analysis in adult spinal deformity(Spine Journal, 2024-09-01) Williamson, TK; Onafowokan, O; Owusu-Sarpong, S; Lebovic, J; Mir, J; Das, A; Diebo, BG; Lafage, R; Lafage, V; Passias, PGBACKGROUND CONTEXT: Pelvic incidence (PI) serves as the cornerstone for realignment schema to create a more individualized realignment target. Yet, it is not known if outcomes of realignment schema are dependent on the amount of pelvic incidence. The purpose of this study is to assess how varying realignment strategies affect mechanical failure and clinical outcomes in PI-stratified cohorts following ASD surgery. PURPOSE: The purpose of this study is to assess how varying realignment strategies affect mechanical failure and clinical outcomes in PI-stratified cohorts following ASD surgery. STUDY DESIGN/SETTING: Retrospective cohort study; Single academic center. PATIENT SAMPLE: A total of 445 adult patients met radiographic criteria for adult spinal deformity. OUTCOME MEASURES: Mechanical failure (either a major hardware failure requiring intervention or proximal junctional failure [PJF]); Clinical Improvement at two years: [meeting either: (1) Substantial Clinical Benefit for Oswestry Disability Index (change >18.8), or (2) Oswestry Disability Index <15 and Scoliosis Research Society Total>4.5]; Good Outcome involved meeting Clinical Improvement criteria with absence of mechanical failure by two years. METHODS: Conditional Inference Tree (CIT) analysis was utilized to define subsets within pelvic incidence generating significantly different rates of mechanical failure. These subsets of pelvic incidence were further analyzed as sub-cohorts for the outcomes and effects of realignment within each. Multivariate logistic regression analysis controlling for baseline frailty and lumbar lordosis (L1-S1) analyzed the association of age-adjusted realignment (Sagittal Age-Adjusted Score [SAAS]; Lafage et al) and Global and Alignment Proportionment (GAP; Yilgor et al) strategies with meeting Good Outcome within PI-stratified groups. RESULTS: Using CIT analysis, a parabolic relationship between PI and mechanical failure was seen, whereas patients with either less than 51° (n=174; 39.1% of cohort) or greater than 63° (n=114; 25.2% of cohort) of pelvic incidence generated higher rates of mechanical failure (18.0% and 20.0%, respectively) and lower rates of Good Outcome (80.3% and 77.6%, respectively) than those with moderate (51-63°) pelvic incidence (n=145, 32.6% of cohort; 8.9% mechanical failure, 92.2% Good Outcome). Patients with Lower PI (<51°) more often met Good Outcome when undercorrected in age-adjusted PI-LL and SAAS overall (12.3% vs 0.0%; p=.004). Patients not meeting Good Outcome in this group were more likely to deteriorate in GAP Relative Lordosis from first to final follow-up (OR: 13.4, 95% CI: 1.3-39.2), leading to a higher likelihood of mechanical failure (OR: 3.2, 95% CI: 1.34-7.52; p=.009). In those with moderate pelvic incidence (51-63°), patients were more likely to meet Good Outcome when aligned in GAP Lumbar Distribution Index (OR: 1.7, 95% CI: 1.1-3.3; p=.029), and those not meeting Good Outcome criteria were more likely to deteriorate in Lumbar Distribution Index from first to final follow-up (OR: 5.8, 95% CI: 1.7-19.8; p=.005). While these patients had noticeably higher rates of failure (20.0% vs 8.9%; p=.123), patients losing alignment in LDI had significantly lower rates of reaching Clinical Improvement criteria (30.0% vs 66.7%, p=.004). Patients with higher pelvic incidence (>63°) meeting Good Outcome were more likely to be overcorrected in SVA (OR: 2.4, 95% CI: 1.1-5.2; p=.033) at first follow-up. and were less likely to be undercorrected in T1PA (OR: 0.4, [0.17-0.86]; p=.020) by final follow-up. When assessing GAP alignment, patients were more likely to meet Good Outcome when aligned in GAP Lumbar Distribution Index (OR: 3.5, 95% CI: 1.4-8.9; p=.007). CONCLUSIONS: There is a parabolic relationship between pelvic incidence and both mechanical failure and clinical improvement following correction of adult spinal deformity. Patients with lower pelvic incidence may fare better with undercorrection in age-adjusted alignment, while those with higher pelvic may necessitate proper distribution of lordosis within the lumbar spine. In addition, loss of in-construct alignment led to higher rates of mechanical failure within low pelvic incidence and less clinical improvement among those with a higher grade. Understanding of the associations this fixed parameter has with poor outcomes can aid the surgeon in strategical planning when seeking to realign adult spinal deformity. FDA Device/Drug Status: This abstract does not discuss or include any applicable devices or drugs.Item Open Access The cervical lordosis distribution index and its consideration of upper cervical region and morphology(Spine Journal, 2024-09-01) Williamson, TK; Passias, PG; Smith, JS; Lafage, R; Line, B; Diebo, BG; Daniels, AH; Gum, JL; Protopsaltis, TS; Hamilton, DK; Soroceanu, A; Eastlack, RK; Mundis, GM; Bess, S; Schwab, FJ; Shaffrey, CI; Lafage, V; Burton, DCBACKGROUND CONTEXT: The cervical lordosis distribution in relation to its apex has not been characterized, nor has the impact of morphologic differences and upper cervical segments. PURPOSE: The goal of this study is assess whether tailored correction of cervical deformity by incorporating the cervical apex into a distribution index (CLDI) improves clinical outcomes while lowering rates of junctional failure. STUDY DESIGN/SETTING: Retrospective review of a prospectively-collected cohort; Multiple academic centers. PATIENT SAMPLE: A total of 84 patients met radiographic criteria for adult cervical deformity and at least 2-year follow-up. OUTCOME MEASURES: Optimal outcome is defined as meeting Virk et al Good Clinical Outcome (GCO): [Meeting 2 of 3: 1) NDI<20 or meeting MCID, 2) mJOA>=14, 3) NRS-Neck<=5 or improved by >2 points] and no occurrence of distal junctional failure (DJF). METHODS: C2-T2 lordosis was divided into cranial (C2-to-apex) and caudal (apex-to-T2) arches. A cervical lordosis distribution index (CLDI) was developed by dividing the cranial lordotic arch (C2 to apex) by the total segment (C2-T2) and multiplying by 100. Cross-tabulations developed categories for CLDI producing the highest chi-square values for achieving Optimal Outcome at two years and outcomes were assessed by multivariable analysis controlling for significant confounders. Patients stratified by Ames et al deformity classification then assessed against thresholds. Patients were further divided into those meeting thresholds with upper cervical compensation (defined by C0-C2 angle, C0 slope, McGregor's Slope [MGS]) vs without compensation. Multivariate regression analysis controlling for T1 slope assessed differences in classification and impact of upper cervical region. RESULTS: Cervical apex distribution postoperatively was: 1% C3, 42% C4, 30% C5, 27% C6. Mean cervical LDI was 117±138. Mean cranial lordosis was 23.2±12.5°. Using cross-tabulations, CLDI between 70 and 90 was defined as ‘Aligned’. Chi-square test revealed significant differences among CLDI categories for DJK, DJF, Good Clinical Outcome, and Optimal Outcome (all p<.05). Patients aligned in CLDI were less likely to develop DJK (OR: 0.1, [<0.1-0.9]), more like to achieve GCO (OR: 3.9, [1.2-13.2]) and Optimal Outcome (OR: 7.9, [2.1-29.3]) at two years. Patients aligned in CLDI developed DJF at a rate of 0%. Those meeting this CLDI threshold were more likely to be classified into primarily cervical deformity by Ames criteria (OR: 1.9, [3.2-10.6], p<.05). CONCLUSIONS: The cervical lordosis distribution index, classified through the cranial segment, takes each unique cervical apex into account and tailors correction to the patient in order to better achieve good clinical outcomes. While differences based on morphology exists, upper cervical region functions as a reserve in all deformity types. Consideration of regional and global factors allows for a comprehensive assessment and individualization of realignment surgery. FDA Device/Drug Status: This abstract does not discuss or include any applicable devices or drugs.Item Open Access Three-dimensional evaluation of the dynamic interplay between pelvic anatomy, lower-limb compensation, and standing alignment in ASD(Spine Journal, 2024-09-01) Assi, A; Khalifé, M; Prince, G; Boutros, M; Karam, M; Ames, CP; Bess, S; Daniels, AH; Gupta, MC; Hostin, RA; Kelly, MP; Kim, HJ; Klineberg, EO; Lenke, LG; Nunley, PD; Passias, PG; Schwab, FJ; Shaffrey, CI; Smith, JS; Lafage, R; Diebo, BG; Lafage, VBACKGROUND CONTEXT: Previous studies have shown that lower limbs play a crucial role in compensating for sagittal spinal malalignment. However, these studies primarily focused on lower limb parameters in the sagittal plane, mainly knee flexion, leaving compensatory mechanisms that might happen in the coronal or axial planes unexplored. PURPOSE: This study aimed to investigate factors associated with lower-limb recruitment in adult spinal deformity (ASD) patients. STUDY DESIGN/SETTING: Retrospective study of prospectively collected data. PATIENT SAMPLE: ASD patients who underwent full-body biplanar X-rays and 3D reconstruction of lower limbs and pelvis. OUTCOME MEASURES: Association between morphological parameters and compensatory mechanisms METHODS: The study included ASD patients with moderate to severe sagittal plane deformities. Classic 2D parameters included pelvic shift (PSh), knee flexion (KA), sacro-femoral (SFA), and ankle dorsiflexion (AA) angles for the lower limbs, as well as TPA, PT, PI, and PI-LL mismatch. 3D reconstructions were used to assess acetabular parameters (abduction, coverage, and anteversion), pelvic depth (PD: distance between the pubic symphysis and the sacral endplate), and knee varus/valgus angle. After univariate analysis, multiple linear regressions were performed to investigate associations between spinal deformity and lower limb 2D/3D parameters with and without accounting for spinal alignment. RESULTS: A total of 146 subjects (67±10 years) were included with a mean PI-LL of 25.1±16.1°, TPA 37.4±10.6°, PT 27±9.1°, and PD of 85.9±16.2mm. Lower limbs compensation consisted of a PSh 38.4±43.7mm, KA 6.9±7.9°, and AA of 5.8±4.1°. Pelvic depth significantly correlated with PI (r=0.6, p<0.001), PT (r=0.3, p<0.001), and SFA (r=0.2, p=0.02). In multivariate analysis considering the full-body parameters, ankle dorsiflexion (AA) was associated with PT, PSh, and KA (all p<0.001) but not with spinal alignment and correlated with increased knee varus angulation (p=0.01). Similarly, KA correlated with PT, SFA, and AA (all p<0.001) but not with spinal alignment. Those associations remained significant in multivariate analysis considering only the lower-limbs parameters. In addition, patients with high pelvic depth (>100mm) had greater pelvic shift and PT than low ones (<70mm): 29.4+49.1mm versus 54.8±41.7mm and 23.7±9.3° versus 32.4±9.4°. Finally, increased PT was associated with higher PI (p<0.001) and more vertical acetabular abduction (57.4±3.9° for PT<15°, vs 60.7±4.2° for PT > 25°, p=0.009). CONCLUSIONS: There was 3D analysis of the lower extremities that revealed significant multiplanar interplay in the setting of spinal deformity. Pelvic morphology including antero-posterior depth is associated with greater compensatory abilities such as pelvic translation and retroversion. Greater PT compensation in the sagittal plane is associated with a more vertical acetabulum in the coronal plane. Knee and ankle flexion were indirectly correlated with spinal alignment as they contributed to higher PT and pelvic shift. Consequently, their assessment is valuable for understanding how patients compensate for malalignment but should not be a primary consideration in the correction strategy. The sagittal and coronal alignment of lower limbs cannot be separated, as an increase in ankle and knee flexion angles is associated with greater genu varum. FDA Device/Drug Status: This abstract does not discuss or include any applicable devices or drugs.Item Open Access Who are super-utilizers in adult spine deformity surgery and how can surgeons identify them preoperatively?(Spine Journal, 2024-09-01) Nayak, P; Hostin, RA; Staub, BN; Gum, JL; Line, B; Bess, S; Lenke, LG; Lafage, R; Smith, JS; Mullin, JP; Kelly, MP; Diebo, BG; Buell, TJ; Scheer, JK; Lafage, V; Klineberg, EO; Kim, HJ; Passias, PG; Kebaish, KM; Eastlack, RK; Daniels, AH; Soroceanu, A; Mundis, GM; Protopsaltis, TS; Hamilton, DK; Gupta, MC; Schwab, FJ; Shaffrey, CI; Ames, CP; Burton, DCBACKGROUND CONTEXT: A relatively small percentage of patients are responsible for a disproportional amount of resource utilization in adult ASD surgery and contribute to significantly elevating the average cost across the surgically treated patients. These patients are called super-utilizers (SU). Modest reduction in the frequency of these super-utilization episodes has the potential to significantly improve the value of ASD surgery. PURPOSE: The goal of this study was to determine which, if any, baseline patient, radiographic, and/or surgical factors are the most important drivers of this disproportional increased resource utilization. We hypothesize that baseline patient factors predicts super-utilizers (SU) in adult spinal deformity surgery (ASD) more than surgical or deformity factors. STUDY DESIGN/SETTING: Retrospective Review of a prospective, multicenter registry. PATIENT SAMPLE: A total of 1299 index operative ASD patients eligible for 2-yr follow-up. OUTCOME MEASURES: Predictors of SU vs Non-SU in ASD. METHODS: A prospective multicenter consecutive series of ASD patients was reviewed. Inclusion criteria was diagnosis of ASD (scoliosis≥20°, C7-SVA≥5cm, PT≥25°, or TK≥60°), >4 level posterior fusion, and minimum 2-year follow-up. Index and total episode of care (EOC) cost in 2022 dollars were calculated using average itemized direct costs obtained from the administrative hospital records for all events in the inpatient EOC. Patients with total 2-year EOC cost greater than 90th percentile were considered SU. Multivariate generalized linear models were used to identify the most significant predictors of SU. RESULTS: A total of 1299 patients were eligible for 2-yr follow-up with mean age 60.0+14.1 years, 76% female, and 93% caucasians. SU patients are marginally older (+2.6 yrs; p=0.03), depressed (34.2% vs 25.8%; p=0.03) and tend to have higher propensity for fraility (p=0.003), comorbidities (0.01), reoperation rates (54.8% vs 17.0%; p<0.001), and LOS (+3 days; p<0.0001) compared to non-SU. While degree of sagittal deformity (Schwab sagittal modifiers, all p>0.05) and proportion of 3-column osteotomies (p>0.05) were similar between the groups, SU patients have higher surgical invasiveness score (+28; p<0.001), more vertebrae fused (+3; p<0.0001); more interbody fusions (80% vs 55%; p<0.0001), more BMP use (87.3% vs 69.4%; p=0.0002); longer OR time (+91 mins; p<0.0001), increased blood loss (+700 mL; p<0.0001), and longer length of stay (+3 days; p<0.0001). Index and EOC cost were 49% (p<0.0001) and 62% (p<0.0001) higher respectively in SU. While cost/QALY was 3-times higher in SU compared to non-SU. Multivariate analysis identified Schwab modifier SVA, surgical invasiveness, OR time, blood loss, BMP use, and LOS as strong predictors of SU (all p<0.01). CONCLUSIONS: Surgical invasiveness score greater than 118, being in OR for more than 7.6 hrs, blood loss more than 700 ml, utilizing BMP, and LOS more than 11 days were strong predictors of being a SU. Patients with SVA grade of + and ++ were less likely to be a SU compared to SVA grade 0. Procedural and resource utilization factors were strong predictors of being a SU compared to patient factors. FDA Device/Drug Status: This abstract does not discuss or include any applicable devices or drugs.