Browsing by Author "Ames, Christopher P"
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Item Open Access A comparative analysis of the prevalence and characteristics of cervical malalignment in adults presenting with thoracolumbar spine deformity based on variations in treatment approach over 2 years.(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, 2016-08) Jalai, Cyrus M; Passias, Peter G; Lafage, Virginie; Smith, Justin S; Lafage, Renaud; Poorman, Gregory W; Diebo, Bassel; Liabaud, Barthélemy; Neuman, Brian J; Scheer, Justin K; Shaffrey, Christopher I; Bess, Shay; Schwab, Frank; Ames, Christopher P; International Spine Study Group (ISSG)Purpose
Characteristics specific to cervical deformity (CD) concomitant with adult thoracolumbar deformity (TLD) remains uncertain, particularly regarding treatment. This study identifies cervical malalignment prevalence following surgical and conservative TLD treatment through 2 years.Methods
Retrospective analysis of a prospective, multicenter adult spinal deformity (ASD) database. CD was defined in operative and non-operative ASD patients according to the following criteria: T1 Slope minus Cervical Lordosis (T1S-CL) ≥20°, C2-C7 Cervical Sagittal Vertical Axis (cSVA) ≥40 mm, C2-C7 kyphosis >10°. Differences in rates, demographics, health-related quality of life (HRQoL) scores for Oswestry Disability Index (ODI) and Scoliosis Research Society Questionnaire (SRS-22r), and radiographic variables were assessed between treatment groups (Op vs. Non-Op) and follow-up periods (baseline, 1-year, 2-year).Results
Three hundred and nineteen (200 Op, 199 Non-Op) ASD patients were analyzed. Op patients' CD rates at 1 and 2 years were 78.9, and 63.0 %, respectively. Non-Op CD rates were 21.1 and 37.0 % at 1 and 2 years, respectively. T1S-CL mismatch and cSVA malalignment characterized Op CD at 1 and 2 years (p < 0.05). Op and Non-Op CD groups had similar cervical/global alignment at 1 year (p > 0.05 for all), but at 2 years, Op CD patients had worse thoracic kyphosis (TK), T1S-CL, CL, cSVA, C2-T3 SVA, and global SVA compared to Non-Ops (p < 0.05). Op CD patients had worse ODI, and SRS Activity at 1 and 2 years post-operative (p < 0.05), but had greater 2-year SRS Satisfaction scores (p = 0.019).Conclusions
In the first study to compare cervical malalignment at extended follow-up between ASD treatments, CD rates rose overall through 2 years. TLD surgery, resulting in higher CD rates characterized by T1S-CL and cSVA malalignment, produced poorer HRQoL. This information can aid in treatment method decision-making when cervical deformity is present concomitant with TLD.Item Open Access A Comparison of Three Different Positioning Techniques on Surgical Corrections and Postoperative Alignment in Cervical Spinal Deformity (CD) Surgery.(Spine, 2021-05) Morse, Kyle W; Lafage, Renaud; Passias, Peter; Ames, Christopher P; Hart, Robert; Shaffrey, Christopher I; Mundis, Gregory; Protopsaltis, Themistocles; Gupta, Munish; Klineberg, Eric; Burton, Doug; Lafage, Virginie; Kim, Han Jo; International Spine Study GroupStudy design
Retrospective review of a prospective multicenter cervical deformity database.Objective
To examine the differences in sagittal alignment correction between three positioning methods in cervical spinal deformity surgery (CD).Summary of background data
Surgical correction for CD is technically demanding and various techniques are utilized to achieve sagittal alignment objectives. The effect of different patient positioning techniques on sagittal alignment correction following CD remains unknown.Methods
Patients with sagittal deformity who underwent a posterior approach (with and without anterior approach) with an upper instrumented vertebra of C6 or above. Patients with Grade 5, 6, or 7 osteotomies were excluded. Positioning groups were Mayfield skull clamp, bivector traction, and halo ring. Preoperative lower surgical sagittal curve (C2-C7), C2-C7 sagittal vertical axis (cSVA), cervical scoliosis, T1 slope minus cervical lordosis (TS-CL), T1 slope (T1S), chin-brow vertebral angle (CBVA), C2-T3 curve, and C2-T3 SVA was assessed and compared with postoperative radiographs. Segmental changes were analyzed using the Fergusson method.Results
Eighty patients (58% female) with a mean age of 60.6 ± 10.5 years (range, 31-83) were included. The mean postoperative C2-C7 lordosis was 7.8° ± 14 and C2-C7 SVA was 34.1 mm ± 15. There were overall significant changes in cervical alignment across the entire cohort, with improvements in T1 slope (P < 0.001), C2-C7 (P < 0.001), TS-CL (P < 0.001), and cSVA (P = 0.006). There were no differences postoperatively of any radiographic parameter between positioning groups (P > 0.05). The majority of segmental lordotic correction was achieved at C4-5-6 (mean 6.9° ± 11). Additionally, patients who had bivector traction applied had had significantly more segmental correction at C7-T1-T2 compared with Mayfield and halo traction (4.2° vs. 0.3° vs. -1.7° respectively, P < 0.027).Conclusion
Postoperative cervical sagittal correction or alignment was not affected by patient position. The majority of segmental correction occurred at C4-5-6 across all positioning methods, while bivector traction had the largest corrective ability at the cervicothoracic junction.Level of Evidence: 4.Item Open Access A Comprehensive Review of Complication Rates After Surgery for Adult Deformity: A Reference for Informed Consent.(Spine deformity, 2015-11) Sciubba, Daniel M; Yurter, Alp; Smith, Justin S; Kelly, Michael P; Scheer, Justin K; Goodwin, C Rory; Lafage, Virginie; Hart, Robert A; Bess, Shay; Kebaish, Khaled; Schwab, Frank; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study Group (ISSG)Objective
An up-to-date review of recent literatures and a comprehensive reference for informed consent specific to ASD complications is lacking. The goal of the present study was to determine current complication rates after ASD surgery, in order to provide a reference for informed consent as well as to determine differences between three-column and non-three-column osteotomy procedures to aid in shared decision making.Methods
A review of the literature was conducted using the PubMed database. Randomized controlled trials, nonrandomized trials, cohort studies, case-control studies, and case series providing postoperative complications published in 2000 or later were included. Complication rates were recorded and calculated for perioperative (both major and minor) and long-term complication rates. Postoperative outcomes were all stratified by surgical procedure (ie, three-column osteotomy and non-three-column osteotomy).Results
Ninety-three articles were ultimately eligible for analysis. The data of 11,692 patients were extracted; there were 3,646 complications, mean age at surgery was 53.3 years (range: 25-77 years), mean follow-up was 3.49 years (range: 6 weeks-9.7 years), estimated blood loss was 2,161 mL (range: 717-7,034 mL), and the overall mean complication rate was 55%. Specifically, major perioperative complications occurred at a mean rate of 18.5%, minor perioperative complications occurred at a mean rate of 15.7%, and long-term complications occurred at a mean rate of 20.5%. Furthermore, three-column osteotomy resulted in a higher overall complication rate and estimated blood loss than non-three-column osteotomy.Conclusions
A review of recent literatures providing complication rates for ASD surgery was performed, providing the most up-to-date incidence of early and late complications. Providers may use such data in helping to counsel patients of the literature-supported complication rates of such procedures despite the planned benefits, thus obtaining a more thorough informed consent.Item Open Access A cost-effectiveness comparisons of adult spinal deformity surgery in the United States and Japan.(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, 2018-03) Yagi, Mitsuru; Ames, Christopher P; Keefe, Malla; Hosogane, Naobumi; Smith, Justin S; Shaffrey, Christopher I; Schwab, Frank; Lafage, Virginie; Shay Bess, R; Matsumoto, Morio; Watanabe, Kota; International Spine Study Group (ISSG)Purpose
Information about the cost-effectiveness of surgical procedures for adult spinal deformity (ASD) is critical for providing appropriate treatments for these patients. The purposes of this study were to compare the direct cost and cost-effectiveness of surgery for ASD in the United States (US) and Japan (JP).Methods
Retrospective analysis of 76 US and 76 JP patients receiving surgery for ASD with ≥2-year follow-up was identified. Data analysis included preoperative and postoperative demographic, radiographic, health-related quality of life (HRQOL), and direct cost for surgery. An incremental cost-effectiveness ratio (ICER) was determined using cost/quality-adjusted life years (QALY). The cost/QALY was calculated from the 2-year cost and HRQOL data.Results
JP exhibited worse baseline spinopelvic alignment than the US (pelvic incidence and lumbar lordosis: 35.4° vs 22.7°, p < 0.01). The US had more three-column osteotomies (50 vs 16%), and shorter hospital stay (7.9 vs 22.7 days) (p < 0.05). The US demonstrated worse postoperative ODI (41.3 vs. 33.9%) and greater revision surgery rate (40 vs 10%) (p < 0.05). Due to the high initial cost and revision frequency, the US had greater total cost ($92,133 vs. $49,647) and cost/QALY ($511,840 vs. $225,668) at 2-year follow-up (p < 0.05).Conclusion
Retrospective analysis comparing the direct costs and cost-effectiveness of ASD surgery in the US vs JP demonstrated that the total direct costs and cost/QALY were substantially higher in the US than JP. Variations in patient cohort, healthcare costs, revision frequencies, and HRQOL improvement influenced the cost/QALY differential between these countries.Item Open Access A Pilot Study on Posterior Polyethylene Tethers to Prevent Proximal Junctional Kyphosis After Multilevel Spinal Instrumentation for Adult Spinal Deformity.(Operative neurosurgery (Hagerstown, Md.), 2019-02) Buell, Thomas J; Buchholz, Avery L; Quinn, John C; Bess, Shay; Line, Breton G; Ames, Christopher P; Schwab, Frank J; Lafage, Virginie; Shaffrey, Christopher I; Smith, Justin SBACKGROUND:Proximal junctional kyphosis (PJK) is a common problem after multilevel spine instrumentation. OBJECTIVE:To determine if junctional tethers reduce PJK after multilevel instrumented surgery for adult spinal deformity (ASD). METHODS:ASD patients who underwent posterior instrumented fusion were divided into 3 groups: no tether (NT), polyethylene tether-only (TO; tied securely through the spinous processes of the uppermost instrumented vertebra [UIV] + 1 and UIV-1), and tether with crosslink (TC; passed through the spinous process of UIV+1 and tied to a crosslink between UIV-1 and UIV-2). PJK was defined as proximal junctional angle ≥ 10° and ≥ 10° greater than the corresponding preoperative measurement. RESULTS:One hundred eighty-four (96%) of 191 consecutive patients achieved minimum 3-mo follow-up (mean = 20 mo [range:3-56 mo]; mean age = 66 yr; 67.4% female). There were no significant differences between groups based on demographic, surgical, and sagittal radiographic parameters. PJK rates were 45.3% (29/64), 34.4% (22/64), and 17.9% (10/56) for NT, TO, and TC, respectively. PJK rate for all tethered patients (TO + TC; 26.7% [32/120]) was significantly lower than NT (P = .011). PJK rate for TC was significantly lower than NT (P = .001). Kaplan-Meier analysis showed significant time-dependent PJK reduction for TC vs NT (log rank test, P = .010). Older age and greater change in lumbar lordosis were independent predictors of PJK, while junctional tethers had a significant protective effect. CONCLUSION:Junctional tethers significantly reduced occurrence of PJK. This difference was progressive from NT to TO to TC, but only reached pairwise significance for NT vs TC. This suggests potential benefit of tethers to reduce PJK, and that future prospective studies are warranted.Item Open Access A standardized nomenclature for cervical spine soft-tissue release and osteotomy for deformity correction: clinical article.(Journal of neurosurgery. Spine, 2013-09) Ames, Christopher P; Smith, Justin S; Scheer, Justin K; Shaffrey, Christopher I; Lafage, Virginie; Deviren, Vedat; Moal, Bertrand; Protopsaltis, Themistocles; Mummaneni, Praveen V; Mundis, Gregory M; Hostin, Richard; Klineberg, Eric; Burton, Douglas C; Hart, Robert; Bess, Shay; Schwab, Frank J; International Spine Study GroupObject
Cervical spine osteotomies are powerful techniques to correct rigid cervical spine deformity. Many variations exist, however, and there is no current standardized system with which to describe and classify cervical osteotomies. This complicates the ability to compare outcomes across procedures and studies. The authors' objective was to establish a universal nomenclature for cervical spine osteotomies to provide a common language among spine surgeons.Methods
A proposed nomenclature with 7 anatomical grades of increasing extent of bone/soft tissue resection and destabilization was designed. The highest grade of resection is termed the major osteotomy, and an approach modifier is used to denote the surgical approach(es), including anterior (A), posterior (P), anterior-posterior (AP), posterior-anterior (PA), anterior-posterior-anterior (APA), and posterior-anterior-posterior (PAP). For cases in which multiple grades of osteotomies were performed, the highest grade is termed the major osteotomy, and lower-grade osteotomies are termed minor osteotomies. The nomenclature was evaluated by 11 reviewers through 25 different radiographic clinical cases. The review was performed twice, separated by a minimum 1-week interval. Reliability was assessed using Fleiss kappa coefficients.Results
The average intrarater reliability was classified as "almost perfect agreement" for the major osteotomy (0.89 [range 0.60-1.00]) and approach modifier (0.99 [0.95-1.00]); it was classified as "moderate agreement" for the minor osteotomy (0.73 [range 0.41-1.00]). The average interrater reliability for the 2 readings was the following: major osteotomy, 0.87 ("almost perfect agreement"); approach modifier, 0.99 ("almost perfect agreement"); and minor osteotomy, 0.55 ("moderate agreement"). Analysis of only major osteotomy plus approach modifier yielded a classification that was "almost perfect" with an average intrarater reliability of 0.90 (0.63-1.00) and an interrater reliability of 0.88 and 0.86 for the two reviews.Conclusions
The proposed cervical spine osteotomy nomenclature provides the surgeon with a simple, standard description of the various cervical osteotomies. The reliability analysis demonstrated that this system is consistent and directly applicable. Future work will evaluate the relationship between this system and health-related quality of life metrics.Item Open Access Adult Cervical Deformity Patients Have Higher Baseline Frailty, Disability, and Comorbidities Compared With Complex Adult Thoracolumbar Deformity Patients: A Comparative Cohort Study of 616 Patients.(Global spine journal, 2023-11) Smith, Justin S; Kelly, Michael P; Buell, Thomas J; Ben-Israel, David; Diebo, Bassel; Scheer, Justin K; Line, Breton; Lafage, Virginie; Lafage, Renaud; Klineberg, Eric; Kim, Han Jo; Passias, Peter; Gum, Jeffrey L; Kebaish, Khal; Mullin, Jeffrey P; Eastlack, Robert; Daniels, Alan; Soroceanu, Alex; Mundis, Gregory; Hostin, Richard; Protopsaltis, Themistocles S; Hamilton, D Kojo; Gupta, Munish; Lewis, Stephen J; Schwab, Frank J; Lenke, Lawrence G; Shaffrey, Christopher I; Burton, Douglas; Ames, Christopher P; Bess, Shay; International Spine Study GroupStudy design
Multicenter comparative cohort.Objective
Studies have shown markedly higher rates of complications and all-cause mortality following surgery for adult cervical deformity (ACD) compared with adult thoracolumbar deformity (ATLD), though the reasons for these differences remain unclear. Our objectives were to compare baseline frailty, disability, and comorbidities between ACD and complex ATLD patients undergoing surgery.Methods
Two multicenter prospective adult spinal deformity registries were queried, one ATLD and one ACD. Baseline clinical and frailty measures were compared between the cohorts.Results
616 patients were identified (107 ACD and 509 ATLD). These groups had similar mean age (64.6 vs 60.8 years, respectively, P = .07). ACD patients were less likely to be women (51.9% vs 69.5%, P < .001) and had greater Charlson Comorbidity Index (1.5 vs .9, P < .001) and ASA grade (2.7 vs 2.4, P < .001). ACD patients had worse VR-12 Physical Component Score (PCS, 25.7 vs 29.9, P < .001) and PROMIS Physical Function Score (33.3 vs 35.3, P = .031). All frailty measures were significantly worse for ACD patients, including hand dynamometer (44.6 vs 55.6 lbs, P < .001), CSHA Clinical Frailty Score (CFS, 4.0 vs 3.2, P < .001), and Edmonton Frailty Scale (EFS, 5.15 vs 3.21, P < .001). Greater proportions of ACD patients were frail (22.9% vs 5.7%) or vulnerable (15.6% vs 10.9%) based on EFS (P < .001).Conclusions
Compared with ATLD patients, ACD patients had worse baseline characteristics on all measures assessed (comorbidities/disability/frailty). These differences may help account for greater risk of complications and all-cause mortality previously observed in ACD patients and facilitate strategies for better preoperative optimization.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 Adult Spinal Deformity Patients Recall Fewer Than 50% of the Risks Discussed in the Informed Consent Process Preoperatively and the Recall Rate Worsens Significantly in the Postoperative Period.(Spine, 2015-07) Saigal, Rajiv; Clark, Aaron J; Scheer, Justin K; Smith, Justin S; Bess, Shay; Mummaneni, Praveen V; McCarthy, Ian M; Hart, Robert A; Kebaish, Khaled M; Klineberg, Eric O; Deviren, Vedat; Schwab, Frank; Shaffrey, Christopher I; Ames, Christopher PStudy design
Recall of the informed consent process in patients undergoing adult spinal deformity surgery and their family members was investigated prospectively.Objective
To quantify the percentage recall of the most common complications discussed during the informed consent process in adult spinal deformity surgery, assess for differences between patients and family members, and correlate with mental status.Summary of background data
Given high rates of complications in adult spinal deformity surgery, it is critical to shared decision making that patients are adequately informed about risks and are able to recall preoperative discussion of possible complications to mitigate medical legal risk.Methods
Patients undergoing adult spinal deformity surgery underwent an augmented informed consent process involving both verbal and video explanations. Recall of the 11 most common complications was scored. Mental status was assessed with the mini-mental status examination-brief version. Patients subjectively scored the informed consent process and video. After surgery, the recall test and mini-mental status examination-brief version were readministered at 5 additional time points: hospital discharge, 6 to 8 weeks, 3 months, 6 months, and 1 year postoperatively. Family members were assessed at the first 3 time points for comparison.Results
Fifty-six patients enrolled. Despite ranking the consent process as important (median overall score: 10/10; video score: 9/10), median patient recall was only 45% immediately after discussion and video re-enforcement and subsequently declined to 18% at 6 to 8 weeks and 1 year postoperatively. Median family recall trended higher at 55% immediately and 36% at 6 to 8 weeks postoperatively. The perception of the severity of complications significantly differs between patient and surgeon. Mental status scores showed a transient, significant decrease from preoperation to discharge but were significantly higher at 1 year.Conclusion
Despite being well-informed in an optimized informed consent process, patients cannot recall most surgical risks discussed and recall declines over time. Significant progress remains to improve informed consent retention.Level of evidence
3.Item Open Access Alignment Risk Factors for Proximal Junctional Kyphosis and the Effect of Lower Thoracic Junctional Tethers for Adult Spinal Deformity.(World neurosurgery, 2019-01) Buell, Thomas J; Chen, Ching-Jen; Quinn, John C; Buchholz, Avery L; Mazur, Marcus D; Mullin, Jeffrey P; Nguyen, James H; Taylor, Davis G; Bess, Shay; Line, Breton G; Ames, Christopher P; Schwab, Frank J; Lafage, Virginie; Shaffrey, Christopher I; Smith, Justin SObjective
The aims of this retrospective cohort study were to 1) identify new alignment risk factors for proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) patients with lower thoracic upper instrumented vertebra (UIV) and 2) determine the effect of junctional tethers on PJK and UIV alignment.Methods
We analyzed consecutive ASD patients who underwent posterior instrumented fusion with lower thoracic UIV (T9-T11). Posteriorly anchored junctional tethers were used more recently for ligamentous augmentation to prevent PJK. In addition to regional and global parameters, upper segmental lumbar lordosis (ULL) versus lower segmental lumbar lordosis and UIV angle (measured from UIV inferior endplate to horizontal) were assessed. Primary outcome of PJK was defined as proximal junctional angle >10° and >10° greater than the corresponding preoperative measurement. Univariable and multivariable analyses were performed.Results
The study cohort comprised 120 ASD patients (mean age, 67 years) with minimum 1-year follow-up. Preoperative ULL (P = 0.034) and UIV angle (P = 0.026) were associated with PJK. No independent preoperative alignment risk factors of PJK were identified in multivariable analysis. Tether use was protective against PJK (odds ratio, 0.063 [0.016-0.247]; P < 0.001). PJK in tethered patients was more common with greater postoperative ULL (P = 0.047) and UIV angle (P = 0.026).Conclusions
Junctional tethers significantly reduced PJK in ASD patients with lower thoracic UIV. In tethered patients, PJK was more common with greater postoperative lordosis of the upper lumbar spine and greater UIV angle. This finding suggests potential benefit of tethers to mitigate effects of segmental lumbar and focal UIV malalignment that may occur after deformity surgery.Item Open Access Alignment Targets, Curve Proportion and Mechanical Loading: Preliminary Analysis of an Ideal Shape Toward Reducing Proximal Junctional Kyphosis.(Global spine journal, 2022-07) Katsuura, Yoshihiro; Lafage, Renaud; Kim, Han Jo; Smith, Justin S; Line, Breton; Shaffrey, Christopher; Burton, Douglas C; Ames, Christopher P; Mundis, Gregory M; Hostin, Richard; Bess, Shay; Klineberg, Eric O; Passias, Peter G; Lafage, Virginie; International Spine Study Group (ISSG)Study design
Retrospective cohort study.Objective
Investigate risk factors for PJK including theoretical kyphosis, mechanical loading at the UIV and age adjusted offset alignment.Methods
373 ASD patients (62.7 yrs ± 9.9; 81%F) with 2-year follow up and UIV of at least L1 and LIV of sacrum were included. Images of patients without PJK, with PJK and with PJF were compared using standard spinopelvic parameters before and after the application of the validated virtual alignment method which corrects for the compensatory mechanisms of PJK. Age-adjusted offset, theoretical thoracic kyphosis and mechanical loading at the UIV were then calculated and compared between groups. A subanalysis was performed based on the location of the UIV (upper thoracic (UT) vs. Lower thoracic (LT)).Results
At 2-years 172 (46.1%) had PJK, and 21 (5.6%) developed PJF. As PJK severity increased, the post-operative global alignment became more posterior secondary to increased over-correction of PT, PI-LL, and SVA (all P < 0.005). Also, a larger under correction of the theoretical TK (flattening) and a smaller bending moment at the UIV (underloading of UIV) was found. Multivariate analysis demonstrated that PI-LL and bending moment offsets from normative values were independent predictors of PJK/PJF in UT group; PT and bending moment difference were independent predictors for LT group.Conclusions
Spinopelvic over correction, under correction of TK (flattening), and under loading of the UIV (decreased bending moment) were associated with PJK and PJF. These differences are often missed when compensation for PJK is not accounted for in post-operative radiographs.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 An Analysis of the Incidence and Outcomes of Major Versus Minor Neurological Decline After Complex Adult Spinal Deformity Surgery: A Subanalysis of Scoli-RISK-1 Study.(Spine, 2018-07) Kato, So; Fehlings, Michael G; Lewis, Stephen J; Lenke, Lawrence G; Shaffrey, Christopher I; Cheung, Kenneth MC; Carreon, Leah Y; Dekutoski, Mark B; Schwab, Frank J; Boachie-Adjei, Oheneba; Kebaish, Khaled M; Ames, Christopher P; Qiu, Yong; Matsuyama, Yukihiro; Dahl, Benny T; Mehdian, Hossein; Pellisé, Ferran; Berven, Sigurd HStudy design
A subanalysis from a prospective, multicenter, international cohort study in 15 sites (Scoli-RISK-1).Objective
To report detailed information regarding the severity of neurological decline related to complex adult spine deformity (ASD) surgery and to examine outcomes based on severity.Summary of background data
Postoperative neurological decline after ASD surgeries can occur due to nerve root(s) or spinal cord dysfunction. The impact of decline and the pattern of recovery may be related to the anatomic location and the severity of the injury.Methods
An investigation of 272 prospectively enrolled complex ASD surgical patients with neurological status measured by American Spinal Injury Association Lower Extremity Motor Scores (LEMS) was undertaken. Postoperative neurological decline was categorized into "major" (≥5 points loss) versus "minor" (<5 points loss) deficits. Timing and extent of recovery in LEMS were investigated for each group.Results
Among the 265 patients with LEMS available at discharge, 61 patients (23%) had neurological decline, with 20 (33%) experiencing major decline. Of note, 90% of the patients with major decline had deficits in three or more myotomes. Full recovery was seen in 24% at 6 weeks and increased to 65% at 6 months. However, 34% continued to experience some neurological decline at 24 months, with 6% demonstrating no improvement. Of 41 patients (67%) with minor decline, 73% had deficits in one or two myotomes. Full recovery was seen in 49% at 6 weeks and increased to 70% at 6 months. Of note, 26% had persistence of some neurological deficit at 24 months, with 18% demonstrating no recovery.Conclusion
In patients undergoing complex ASD correction, a rate of postoperative neurological decline of 23% was noted with 33% of these being "major." Although most patients showed substantial recovery by 6 months, approximately one-third continued to experience neurological dysfunction.Level of evidence
2.Item Open Access An assessment of frailty as a tool for risk stratification in adult spinal deformity surgery.(Neurosurgical focus, 2017-12) Miller, Emily K; Neuman, Brian J; Jain, Amit; Daniels, Alan H; Ailon, Tamir; Sciubba, Daniel M; Kebaish, Khaled M; Lafage, Virginie; Scheer, Justin K; Smith, Justin S; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study GroupOBJECTIVE The goal of this study was to analyze the value of an adult spinal deformity frailty index (ASD-FI) in preoperative risk stratification. Preoperative risk assessment is imperative before procedures known to have high complication rates, such as ASD surgery. Frailty has been associated with risk of complications in trauma surgery, and preoperative frailty assessments could improve the accuracy of risk stratification by providing a comprehensive analysis of patient factors that contribute to an increased risk of complications. METHODS Using 40 variables, the authors calculated frailty scores with a validated method for 417 patients (enrolled between 2010 and 2014) with a minimum 2-year follow-up in an ASD database. On the basis of these scores, the authors categorized patients as not frail (NF) (< 0.3 points), frail (0.3-0.5 points), or severely frail (SF) (> 0.5 points). The correlation between frailty category and incidence of complications was analyzed. RESULTS The overall mean ASD-FI score was 0.33 (range 0.0-0.8). Compared with NF patients (n = 183), frail patients (n = 158) and SF patients (n = 109) had longer mean hospital stays (1.2 and 1.6 times longer, respectively; p < 0.001). The adjusted odds of experiencing a major intraoperative or postoperative complication were higher for frail patients (OR 2.8) and SF patients ( 4.1) compared with NF patients (p < 0.01). For frail and SF patients, respectively, the adjusted odds of developing proximal junctional kyphosis (OR 2.8 and 3.1) were higher than those for NF patients. The SF patients had higher odds of developing pseudarthrosis (OR 13.0), deep wound infection (OR 8.0), and wound dehiscence (OR 13.4) than NF patients (p < 0.05), and they had 2.1 times greater odds of reoperation (p < 0.05). CONCLUSIONS Greater patient frailty, as measured by the ASD-FI, was associated with worse outcome in many common quality and value metrics, including greater risk of major complications, proximal junctional kyphosis, pseudarthrosis, deep wound infection, wound dehiscence, reoperation, and longer hospital stay.Item Open Access Analysis of Successful Versus Failed Radiographic Outcomes After Cervical Deformity Surgery.(Spine, 2018-07) Protopsaltis, Themistocles S; Ramchandran, Subaraman; Hamilton, D Kojo; Sciubba, Daniel; Passias, Peter G; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Hart, Robert A; Gupta, Munish; Burton, Douglas; Bess, Shay; Shaffrey, Christopher; Ames, Christopher P; International Spine Study Group (ISSG)Study design
Prospective multicenter cohort study with consecutive enrollment.Objective
To evaluate preoperative alignment and surgical factors associated with suboptimal early postoperative radiographic outcomes after surgery for cervical deformity.Summary of background data
Recent studies have demonstrated correlation between cervical sagittal alignment and patient-reported outcomes. Few studies have explored cervical deformity correction prospectively, and the factors that result in successful versus failed cervical alignment corrections remain unclear.Methods
Patients with adult cervical deformity (ACD) included with either cervical kyphosis more than 10°, C2-C7 sagittal vertical axis (cSVA) of more than 4 cm, or chin-brow vertical angle of more than 25°. Patients were categorized into failed outcomes group if cSVA of more than 4 cm or T1 slope and cervical lordosis (TS-CL) of more than 20° at 6 months postoperatively.Results
A total of 71 patients with ACD (mean age 62 yr, 56% women, 41% revisions) were included. Fourty-five had primary cervical deformities and 26 at the cervico-thoracic junction. Thirty-three (46.4%) had failed radiographic outcomes by cSVA and 46 (64.7%) by TS-CL. Failure to restore cSVA was associated with worse preoperative C2 pelvic tilt angle (CPT: 64.4° vs. 47.8°, P = 0.01), worse postoperative C2 slope (35.0° vs. 23.8°, P = 0.004), TS-CL (35.2° vs. 24.9°, P = 0.01), CPT (47.9° vs. 28.2°, P < 0.001), "+" Schwab modifiers (P = 0.007), revision surgery (P = 0.05), and failure to address the secondary, thoracolumbar driver of the deformity (P = 0.02). Failure to correct TS-CL was associated with worse preoperative cervical kyphosis (10.4° vs. -2.1°, P = 0.03), CPT (52.6° vs. 39.1°, P = 0.04), worse postoperative C2 slope (30.2° vs. 13.3°, P < 0.001), cervical lordosis (-3.6° vs. -15.1°, P = 0.01), and CPT (37.7° vs. 24.0°, P < 0.001). Multivariate analysis revealed postoperative distal junctional kyphosis associated with suboptimal outcomes by cSVA (odds ratio 0.06, confidence interval 0.01-0.4, P = 0.004) and TS-CL (odds ratio 0.15, confidence interval 0.02-0.97, P = 0.05).Conclusion
Factors associated with failure to correct the cSVA included revision surgery, worse preoperative CPT, and concurrent thoracolumbar deformity. Failure to correct the TS-CL mismatch was associated with worse preoperative cervical kyphosis and CPT. Occurrence of early postoperative distal junctional kyphosis significantly affects postoperative radiographic outcomes.Level of evidence
3.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, 2024-03) 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 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 Appropriate Risk Stratification and Accounting for Age-Adjusted Reciprocal Changes in the Thoracolumbar Spine Reduces the Incidence and Magnitude of Distal Junctional Kyphosis in Cervical Deformity Surgery.(Spine, 2021-11) Passias, Peter G; Bortz, Cole; Pierce, Katherine E; Kummer, Nicholas A; Lafage, Renaud; Diebo, Bassel G; Line, Breton G; Lafage, Virginie; Burton, Douglas C; Klineberg, Eric O; Kim, Han Jo; Daniels, Alan H; Mundis, Gregory M; Protopsaltis, Themistocles S; Eastlack, Robert K; Sciubba, Daniel M; Bess, Shay; Schwab, Frank J; Shaffrey, Christopher I; Smith, Justin S; Ames, Christopher P; International Spine Study Group (ISSG)Study design
Retrospective cohort study of a prospective cervical deformity (CD) database.Objective
Identify factors associated with distal junctional kyphosis (DJK); assess differences across DJK types.Summary of background data
DJK may develop as compensation for mal-correction of sagittal deformity in the thoracic curve. There is limited understanding of DJK drivers, especially for different DJK types.Methods
Included: patients with pre- and postoperative clinical/radiographic data. Excluded: patients with previous fusion to L5 or below. DJK was defined per surgeon note or DJK angle (kyphosis from LIV to LIV-2)<-10°, and pre- to postoperative change in DJK angle by<-10°. Age-specific target LL-TK alignment was calculated as published. Offset from target LL-TK was correlated to DJK magnitude and inclination. DJK types: severe (DJK<-20°), progressive (DJK increase>4.4°), symptomatic (reoperation or published disability thresholds of NDI ≥ 24 or mJOA≤14). Random forest identified factors associated with DJK. Means comparison tests assessed differences.Results
Included: 136 CD patients (61 ± 10 yr, 61%F). DJK rate was 30%. Postop offset from ideal LL-TK correlated with greater DJK angle (r = 0.428) and inclination of the distal end of the fusion construct (r = 0.244, both P < 0.02). Seven of the top 15 factors associated with DJK were radiographic, four surgical, and four clinical. Breakdown by type: severe (22%), progressive (24%), symptomatic (61%). Symptomatic had more posterior osteotomies than asymptomatic (P = 0.018). Severe had worse NDI and upper-cervical deformity (CL, C2 slope, C0-C2), as well as more posterior osteotomies than nonsevere (all P < 0.01). Progressive had greater malalignment both globally and in the cervical spine (all P < 0.03) than static. Each type had varying associated factors.Conclusion
Offset from age-specific alignment is associated with greater DJK and more anterior distal construct inclination, suggesting DJK may develop due to inappropriate realignment. Preoperative clinical and radiographic factors are associated with symptomatic and progressive DJK, suggesting the need for preoperative risk stratification.Level of Evidence: 3.Item Open Access Are Higher Global Alignment and Proportion Scores Associated With Increased Risks of Mechanical Complications After Adult Spinal Deformity Surgery? An External Validation.(Clinical orthopaedics and related research, 2021-02) Kwan, Kenny Yat Hong; Lenke, Lawrence G; Shaffrey, Christopher I; Carreon, Leah Y; Dahl, Benny T; Fehlings, Michael G; Ames, Christopher P; Boachie-Adjei, Oheneba; Dekutoski, Mark B; Kebaish, Khaled M; Lewis, Stephen J; Matsuyama, Yukihiro; Mehdian, Hossein; Qiu, Yong; Schwab, Frank J; Cheung, Kenneth Man Chee; AO Spine Knowledge Forum DeformityBackground
The Global Alignment and Proportion (GAP) score, based on pelvic incidence-based proportional parameters, was recently developed to predict mechanical complications after surgery for spinal deformities in adults. However, this score has not been validated in an independent external dataset.Questions/purposes
After adult spinal deformity surgery, is a higher GAP score associated with (1) an increased risk of mechanical complications, defined as rod fractures, implant-related complications, proximal or distal junctional kyphosis or failure; (2) a higher likelihood of undergoing revision surgery to treat a mechanical complication; and (3) is a lower (more proportioned) GAP score category associated with better validated outcomes scores using the Oswestry Disability Index (ODI), Scoliosis Research Society-22 (SRS-22) and the Short Form-36 questionnaires?Methods
A total of 272 patients who had undergone corrective surgeries for complex spinal deformities were enrolled in the Scoli-RISK-1 prospective trial. Patients were included in this secondary analysis if they fulfilled the original inclusion criteria by Yilgor et al. From the original 272 patients, 14% (39) did not satisfy the radiographic inclusion criteria, the GAP score could not be calculated in 14% (37), and 24% (64) did not have radiographic assessment at postoperative 2 years, leaving 59% (159) for analysis in this review of data from the original trial. A total of 159 patients were included in this study,with a mean age of 58 ± 14 years at the time of surgery. Most patients were female (72%, 115 of 159), the mean number of levels involved in surgery was 12 ± 4, and three-column osteotomy was performed in 76% (120 of 159) of patients. The GAP score was calculated using parameters from early postoperative radiographs (between 3 and 12 weeks) including pelvic incidence, sacral slope, lumbar lordosis, lower arc lordosis and global tilt, which were independently obtained from a computer software based on centralized patient radiographs. The GAP score was categorized as proportional (scores of 0 to 2), moderately disproportional (scores of 3 to 6), or severely disproportional (scores higher than 7 to 13). Receiver operating characteristic area under curve (AUC) was used to assess associations between GAP score and risk of mechanical complications and risk of revision surgery. An AUC of 0.5 to 0.7 was classified as "no or low associative power", 0.7 to 0.9 as "moderate" and greater than 0.9 as "high". We analyzed differences in validated outcome scores between the GAP categories using Wilcoxon rank sum test.Results
At a minimum of 2 years' follow-up, a higher GAP score was not associated with increased risks of mechanical complications (AUC = 0.60 [95% CI 0.50 to 0.70]). A higher GAP score was not associated with a higher likelihood of undergoing a revision surgery to treat a mechanical complication (AUC = 0.66 [95% 0.53 to 0.78]). However, a moderately disproportioned GAP score category was associated with better SF-36 physical component summary score (36 ± 10 versus 40 ± 11; p = 0.047), better SF-36 mental component summary score (46 ± 13 versus 51 ± 12; p = 0.01), better SRS-22 total score (3.4 ± 0.8 versus 3.7 ± 0.7, p = 0.02) and better ODI score (35 ± 21 versus 25 ± 20; p = 0.003) than severely disproportioned GAP score category.Conclusion
Based on the findings of this external validation study, we found that alignment targets based on the GAP score alone were not associated with increased risks of mechanical complications and mechanical revisions in patients with complex adult spinal disorders. Parameters not included in the original GAP score needed to be considered to reduce the likelihood of mechanical complications.Level of evidence
Level III, diagnostic study.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.