Browsing by Author "Shaffrey, Christopher"
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Item Open Access A Multicenter Evaluation of Clinical and Radiographic Outcomes Following High-grade Spondylolisthesis Reduction and Fusion.(Clinical spine surgery, 2017-05) Gandhoke, Gurpreet S; Kasliwal, Manish K; Smith, Justin S; Nieto, JoAnne; Ibrahimi, David; Park, Paul; Lamarca, Frank; Shaffrey, Christopher; Okonkwo, David O; Kanter, Adam SObjective
A retrospective review of the clinical and radiographic outcomes from a multicenter study of surgical treatment for high-grade spondylolisthesis (HGS) in adults. The objective was to assess the safety of surgical reduction, its ability to correct regional deformity, and its clinical effectiveness.Methods
Retrospective, multicenter review of adults (age above 18 y) with lumbosacral HGS (Meyerding grade 3-5) treated surgically with open decompression, attempted reduction, posterior instrumentation, and interbody fusion. Preoperative and postoperative assessment of the Meyerding grade, slip angle, and sacral inclination were performed based on standing radiographs. Preoperative visual analog scale scores were compared with those at the mean follow-up period. Prolo and Oswestry Disability Index scores at most recent follow-up were assessed.Results
A total of 25 patients, aged 19-72 years, met inclusion criteria. Seventeen interbody cages were placed, including 15 transforaminal lumbar interbody fusions, 1 posterior lumbar interbody fusion, and 1 anterior lumbar interbody fusion. Five patients required sacral dome osteotomies. The average follow-up was 21.3 months.At most recent follow-up there was a statistically significant improvement in both the Meyerding grade and the slip angle (P<0.05). There was 1 intraoperative complication resulting in a neurological deficit (4%) and 1 intraoperative vertebral body fracture (4%). No additional surgery was required for any of these patients. There were no cases of nonunion or device failure except for 1 patient who suffered an unrelated traumatic injury 1 year after surgery. The mean Oswestry Disability Index and Prolo scores at mean follow-up of 21.3 months were 20% (minimum disability) and 8.2 (grade 1), respectively.Conclusions
The present study suggests that reduction, when accomplished in conjunction with wide neural element decompression and instrumented arthrodesis, is safe, effective, and durable with low rates of neurological injury, favorable clinical results, and high-fusion rates.Item Open Access A Multicenter Review of Superior Laryngeal Nerve Injury Following Anterior Cervical Spine Surgery.(Global spine journal, 2017-04) Tempel, Zachary J; Smith, Justin S; Shaffrey, Christopher; Arnold, Paul M; Fehlings, Michael G; Mroz, Thomas E; Riew, K Daniel; Kanter, Adam SA retrospective multicenter case-series study; case report and review of the literature.The anatomy and function of the superior laryngeal nerve (SLN) are well described; however, the consequences of SLN injury remain variable and poorly defined. The prevalence of SLN injury as a consequence of cervical spine surgery is difficult to discern as its clinical manifestations are often inconstant and frequently of a subclinical degree. A multicenter study was performed to better delineate the risk factors, prevalence, and outcomes of SLN injury.A retrospective multicenter case-series study involving 21 high-volume surgical centers from the AO Spine North America Clinical Research Network. Medical records for 17 625 patients who received subaxial cervical spine surgery from 2005 to 2011 were reviewed to identify occurrence of 21 predefined treatment complications. Descriptive statistics were provided for baseline patient characteristics. A retrospective review of the neurosurgical literature on SLN injury was also performed.A total of 8887 patients who underwent anterior cervical spine surgery at the participating institutions were screened, and 1 case of SLN palsy was identified. The prevalence ranged from 0% to 1.25% across all centers. The patient identified underwent a C4 corpectomy. The SLN injury was identified after the patient demonstrated difficulty swallowing postoperatively. He underwent placement of a percutaneous gastrostomy tube and his SLN palsy resolved by 6 weeks.This multicenter study demonstrates that identification of SLN injury occurs very infrequently. Symptomatic SLN injury is an exceedingly rare complication of anterior cervical spine surgery. The SLN is particularly vulnerable when exposing the more rostral levels of the cervical spine. Careful dissection and retraction of the longus coli may decrease the risk of SLN injury during anterior cervical surgery.Item Open Access A Multicenter Study of the Presentation, Treatment, and Outcomes of Cervical Dural Tears.(Global spine journal, 2017-04) O'Neill, Kevin R; Fehlings, Michael G; Mroz, Thomas E; Smith, Zachary A; Hsu, Wellington K; Kanter, Adam S; Steinmetz, Michael P; Arnold, Paul M; Mummaneni, Praveen V; Chou, Dean; Nassr, Ahmad; Qureshi, Sheeraz A; Cho, Samuel K; Baird, Evan O; Smith, Justin S; Shaffrey, Christopher; Tannoury, Chadi A; Tannoury, Tony; Gokaslan, Ziya L; Gum, Jeffrey L; Hart, Robert A; Isaacs, Robert E; Sasso, Rick C; Bumpass, David B; Bydon, Mohamad; Corriveau, Mark; De Giacomo, Anthony F; Derakhshan, Adeeb; Jobse, Bruce C; Lubelski, Daniel; Lee, Sungho; Massicotte, Eric M; Pace, Jonathan R; Smith, Gabriel A; Than, Khoi D; Riew, K DanielStudy design
Retrospective multicenter case series study.Objective
Because cervical dural tears are rare, most surgeons have limited experience with this complication. A multicenter study was performed to better understand the presentation, treatment, and outcomes following cervical dural tears.Methods
Multiple surgeons from 23 institutions retrospectively identified 21 rare complications that occurred between 2005 and 2011, including unintentional cervical dural tears. Demographic data and surgical history were obtained. Clinical outcomes following surgery were assessed, and any reoperations were recorded. Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA), Nurick classification (NuC), and Short-Form 36 (SF36) scores were recorded at baseline and final follow-up at certain centers. All data were collected, collated, and analyzed by a private research organization.Results
There were 109 cases of cervical dural tears among 18 463 surgeries performed. In 101 cases (93%) there was no clinical sequelae following successful dural tear repair. There were statistical improvements (P < .05) in mJOA and NuC scores, but not NDI or SF36 scores. No specific baseline or operative factors were found to be associated with the occurrence of dural tears. In most cases, no further postoperative treatments of the dural tear were required, while there were 13 patients (12%) that required subsequent treatment of cerebrospinal fluid drainage. Analysis of those requiring further treatments did not identify an optimum treatment strategy for cervical dural tears.Conclusions
In this multicenter study, we report our findings on the largest reported series (n = 109) of cervical dural tears. In a vast majority of cases, no subsequent interventions were required and no clinical sequelae were observed.Item Open Access A Risk-Benefit Analysis of Increasing Surgical Invasiveness Relative to Frailty Status in Adult Spinal Deformity Surgery.(Spine, 2021-08) Passias, Peter G; Brown, Avery E; Bortz, Cole; Pierce, Katherine; Alas, Haddy; Ahmad, Waleed; Passfall, Lara; Kummer, Nicholas; Krol, Oscar; Lafage, Renaud; Lafage, Virginie; Burton, Douglas; Hart, Robert; Anand, Neel; Mundis, Gregory; Neuman, Brian; Line, Breton; Shaffrey, Christopher; Klineberg, Eric; Smith, Justin; Ames, Christopher; Schwab, Frank J; Bess, Shay; International Spine Study GroupStudy design
Retrospective review of a prospectively enrolled multicenter Adult Spinal Deformity (ASD) database.Objective
Investigate invasiveness and outcomes of ASD surgery by frailty state.Summary of background data
The ASD Invasiveness Index incorporates deformity-specific components to assess correction magnitude. Intersections of invasiveness, surgical outcomes, and frailty state are understudied.Methods
ASD patients with baseline and 3-year (3Y) data were included. Logistic regression analyzed the relationship between increasing invasiveness and major complications or reoperations and meeting minimal clinically important differences (MCID) for health-related quality-of-life measures at 3Y. Decision tree analysis assessed invasiveness risk-benefit cutoff points, above which experiencing complications or reoperations and not reaching MCID were higher. Significance was set to P < 0.05.Results
Overall, 195 of 322 patients were included. Baseline demographics: age 59.9 ± 14.4, 75% female, BMI 27.8 ± 6.2, mean Charlson Comorbidity Index: 1.7 ± 1.7. Surgical information: 61% osteotomy, 52% decompression, 11.0 ± 4.1 levels fused. There were 98 not frail (NF), 65 frail (F), and 30 severely frail (SF) patients. Relationships were found between increasing invasiveness and experiencing a major complication or reoperation for the entire cohort and by frailty group (all P < 0.05). Defining a favorable outcome as no major complications or reoperation and meeting MCID in any health-related quality of life at 3Y established an invasiveness cutoff of 63.9. Patients below this threshold were 1.8[1.38-2.35] (P < 0.001) times more likely to achieve favorable outcome. For NF patients, the cutoff was 79.3 (2.11[1.39-3.20] (P < 0.001), 111 for F (2.62 [1.70-4.06] (P < 0.001), and 53.3 for SF (2.35[0.78-7.13] (P = 0.13).Conclusion
Increasing invasiveness is associated with increased odds of major complications and reoperations. Risk-benefit cutoffs for successful outcomes were 79.3 for NF, 111 for F, and 53.3 for SF patients. Above these, increasing invasiveness has increasing risk of major complications or reoperations and not meeting MCID at 3Y.Level of Evidence: 3.Item Open Access Activity and sports resumption after long segment fusions to the pelvis for adult spinal deformity: survey results of AO Spine members.(Spine deformity, 2023-07) Theologis, Alekos A; Cummins, Daniel D; Kato, So; Lewis, Stephen; Shaffrey, Christopher; Lenke, Lawrence; Berven, Sigurd H; AO Spine Knowledge Forum DeformityPurpose
To assess recommendations for when adult spinal deformity (ASD) patients may return to athletic activities after surgery.Methods
A web-based survey was administered to members of AO Spine. The survey consisted of surgeon demographic information and questions asking when a patient undergoing a long thoracolumbar fusion (> 5 levels) with pelvic fixation for ASD would be allowed to resume unrestricted range of motion (ROM), non-contact sports, and contact sports postoperatively. Ordinal logistic regression was used to determine predictors for time to resume each activity.Results
One hundred twenty four members' responses were included for analysis. The majority of respondents would allow unrestricted ROM within 3 months postop (< 3 months: 81% vs > 3 months: 19%]. For when to return to non-contact sports, the most common responses were "2-3 months" (26.6%), "3-4 months" (26.6%), and "6-12 months" (18.5%). For when to return to contact sports, the majority advised > 4 months postop [> 4 months: "4-6 months" (19.2%), "6-12 months" (28.0%), " > 12 months" (28.8%) versus < 4 months: "1-2 months" (4.0%), "2-3 months" (1.6%), "3-4 months" (8.8%)]. 8.8% responded they would "never" allow resumption of contact sports.Conclusion
There was significant variation between surgeons' recommendations for resumption of unrestricted range of motion and sports following long fusion with pelvic fixation for ASD. An evidence-based approach to activity recommendations will require information on outcomes and complications.Item Open Access Adult cervical spine deformity: a state-of-the-art review.(Spine Deform, 2023-09-30) Jackson-Fowl, Brendan; Hockley, Aaron; Naessig, Sara; Ahmad, Waleed; Pierce, Katherine; Smith, Justin S; Ames, Christopher; Shaffrey, Christopher; Bennett-Caso, Claudia; Williamson, Tyler K; McFarland, Kimberly; Passias, Peter GAdult cervical deformity is a structural malalignment of the cervical spine that may present with variety of significant symptomatology for patients. There are clear and substantial negative impacts of cervical spine deformity, including the increased burden of pain, limited mobility and functionality, and interference with patients' ability to work and perform everyday tasks. Primary cervical deformities develop as the result of a multitude of different etiologies, changing the normal mechanics and structure of the cervical region. In particular, degeneration of the cervical spine, inflammatory arthritides and neuromuscular changes are significant players in the development of disease. Additionally, cervical deformities, sometimes iatrogenically, may present secondary to malalignment or correction of the thoracic, lumbar or sacropelvic spine. Previously, classification systems were developed to help quantify disease burden and influence management of thoracic and lumbar spine deformities. Following up on these works and based on the relationship between the cervical and distal spine, Ames-ISSG developed a framework for a standardized tool for characterizing and quantifying cervical spine deformities. When surgical intervention is required to correct a cervical deformity, there are advantages and disadvantages to both anterior and posterior approaches. A stepwise approach may minimize the drawbacks of either an anterior or posterior approach alone, and patients should have a surgical plan tailored specifically to their cervical deformity based upon symptomatic and radiographic indications. This state-of-the-art review is based upon a comprehensive overview of literature seeking to highlight the normal cervical spine, etiologies of cervical deformity, current classification systems, and key surgical techniques.Item Open Access Adult Scoliosis Deformity Surgery: Comparison of Outcomes Between One Versus Two Attending Surgeons.(Spine, 2017-07) Gomez, Jaime A; Lafage, Virginie; Sciubba, Daniel M; Bess, Shay; Mundis, Gregory M; Liabaud, Barthelemy; Hanstein, Regina; Shaffrey, Christopher; Kelly, Michael; Ames, Christopher; Smith, Justin S; Passias, Peter G; Errico, Thomas; Schwab, Frank; International Spine Study GroupStudy design
Retrospective review of prospectively collected data.Objective
Assess outcomes of adult spinal deformity (ASD) surgery performed by one versus two attending surgeons.Summary of background data
ASD centers have developed two attending teams to improve efficiency; their effects on complications and outcomes have not been reported.Methods
Patients with ASD with five or more levels fused and more than 2-year follow-up were included. Estimated blood loss (EBL), length of stay (LOS), operating room (OR) time, complications, quality of life (Health Related Quality of Life), and x-rays were analyzed. Outcomes were compared between one-surgeon (1S) and two-surgeon (2S) centers. A deformity-matched cohort was analyzed.Results
A total of 188 patients in 1S and 77 in 2S group were included. 2S group patients were older and had worse deformity based on the Scoliosis Research Society-Schwab classification (P < 0.05). There were no significant differences in levels fused (P = 0.57), LOS (8.7 vs 8.9 days), OR time (445.9 vs 453.2 min), or EBL (2008 vs 1898 cm; P > 0.05). 2S patients had more three-column osteotomies (3CO; P < 0.001) and used less bone morphogenetic protein 2 (BMP-2; 79.9% vs 15.6%; P < 0.001). The 2S group had fewer intraoperative complications (1.3% vs 11.1%; P = 0.006). Postoperative (6 wk to 2 yr) complications were more frequent in the 2S group (4.8% vs 15.6%; P < 0.002). After matching for deformity, there were no differences in (9.1 vs 10.1 days), OR time (467.8 vs 508.4 min), or EBL (3045 vs 2247 cm; P = 0.217). 2S group used less BMP-2 (20.6% vs 84.8%; P < 0.001), had fewer intraoperative complications (P = 0.015) but postoperative complications due to instrumentation failure/pseudarthrosis were more frequent (P < 0.01).Conclusion
No significant differences were found in LOS, OR time, or EBL between the 1S and 2S groups, even when matching for severity of deformity. 2S group had less BMP-2 use, fewer intraoperative complications but more postoperative complications.Level of evidence
2.Item Open Access Adult Spinal Deformity Surgery Is Associated with Increased Productivity and Decreased Absenteeism From Work and School.(Spine, 2022-02) Durand, Wesley M; Babu, Jacob M; Hamilton, David K; Passias, Peter G; Kim, Han Jo; Protopsaltis, Themistocles; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Shaffrey, Christopher; Gupta, Munish; Kelly, Michael P; Klineberg, Eric O; Schwab, Frank; Gum, Jeffrey L; Mundis, Gregory; Eastlack, Robert; Kebaish, Khaled; Soroceanu, Alex; Hostin, Richard A; Burton, Doug; Bess, Shay; Ames, Christopher; Hart, Robert A; Daniels, Alan H; International Spine Study Group (ISSG)Study design
Retrospective cohort study.Objective
We hypothesized that adult spinal deformity (ASD) surgery would be associated with improved work- and school-related productivity, as well as decreased rates of absenteeism.Summary of background data
ASD patients experience markedly decreased health-related quality of life along many dimensions.Methods
Only patients eligible for 2-year follow-up were included, and those with a history of previous spinal fusion were excluded. The primary outcome measures in this study were Scoliosis Research Society-22r score (SRS-22r) questions 9 and 17. A repeated measures mixed linear regression was used to analyze responses over time among patients managed operatively (OP) versus nonoperatively (NON-OP).Results
In total, 1188 patients were analyzed. 66.6% were managed operatively. At baseline, the mean percentage of activity at work/school was 56.4% (standard deviation [SD] 35.4%), and the mean days off from work/school over the past 90 days was 1.6 (SD 1.8). Patients undergoing ASD surgery exhibited an 18.1% absolute increase in work/school productivity at 2-year follow-up versus baseline (P < 0.0001), while no significant change was observed for the nonoperative cohort (P > 0.5). Similarly, the OP cohort experienced 1.1 fewer absent days over the past 90 days at 2 years versus baseline (P < 0.0001), while the NON-OP cohort showed no such difference (P > 0.3). These differences were largely preserved after stratifying by baseline employment status, age group, sagittal vertical axis (SVA), pelvic incidence minus lumbar lordosis (PI-LL), and deformity curve type.Conclusion
ASD patients managed operatively exhibited an average increase in work/school productivity of 18.1% and decreased absenteeism of 1.1 per 90 days at 2-year follow-up, while patients managed nonoperatively did not exhibit change from baseline. Given the age distribution of patients in this study, these findings should be interpreted as pertaining primarily to obligations at work or within the home. Further study of the direct and indirect economic benefits of ASD surgery to patients is warranted.Level of Evidence: 3.Item Open Access After 9 Years of 3-Column Osteotomies, Are We Doing Better? Performance Curve Analysis of 573 Surgeries With 2-Year Follow-up.(Neurosurgery, 2018-07) Diebo, Bassel G; Lafage, Virginie; Varghese, Jeffrey J; Gupta, Munish; Kim, Han Jo; Ames, Christopher; Kebaish, Khaled; Shaffrey, Christopher; Hostin, Richard; Obeid, Ibrahim; Burton, Doug; Hart, Robert A; Lafage, Renaud; Schwab, Frank J; International Spine Study Group (ISSG) of Denver, ColoradoBackground
In spinal deformity treatment, the increased utilization of 3-column (3CO) osteotomies reflects greater comfort and better training among surgeons. This study aims to evaluate the longitudinal performance and adverse events (complications or revisions) for a multicenter group following a decade of 3CO.Objective
To investigate if performance of 3CO surgeries improves with years of practice.Methods
Patients who underwent 3CO for spinal deformity with intra/postoperative and revision data collected up to 2 yr were included. Patients were chronologically divided into 4 even groups. Demographics, baseline deformity/correction, and surgical metrics were compared using Student t-test. Postoperative and revision rates were compared using Chi-square analysis.Results
Five hundred seventy-three patients were stratified into: G1 (n = 143, 2004-2008), G2 (n = 142, 2008-2009), G3 (n = 144, 2009-2010), G4 (n = 144 2010-2013). The most recent patients were more disabled by Oswestry disability index (G4 = 49.2 vs G1 = 38.3, P = .001), and received a larger osteotomy resection (G4 = 26° vs G1 = 20°, P = .011) than the earliest group. There was a decrease in revision rate (45%, 35%, 33%, 30%, P = .039), notably in revisions for pseudarthrosis (16.7% G1 vs 6.9% G4, P = .007). Major complication rates also decreased (57%, 50%, 46%, 39%, P = .023) as did excessive blood loss (>4 L, 27.2 vs 16.7%, P = .023) and bladder/bowel deficit (4.2% vs 0.7% P = .002). Successful outcomes (no complications or revision) significantly increased (P = .001).Conclusion
Over 9 yr, 3COs are being performed on an increasingly disabled population while gaining a greater correction at the osteotomy site. Revisions and complication rate decreased while success rate improved during the 2-yr follow-up period.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 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 Anterior versus posterior surgical approaches to treat cervical spondylotic myelopathy: outcomes of the prospective multicenter AOSpine North America CSM study in 264 patients.(Spine, 2013-12) Fehlings, Michael G; Barry, Sean; Kopjar, Branko; Yoon, Sangwook Tim; Arnold, Paul; Massicotte, Eric M; Vaccaro, Alexander; Brodke, Darrel S; Shaffrey, Christopher; Smith, Justin S; Woodard, Eric; Banco, Robert J; Chapman, Jens; Janssen, Michael; Bono, Christopher; Sasso, Rick; Dekutoski, Mark; Gokaslan, Ziya LStudy design
A prospective observational multicenter study.Objective
To help solve the debate regarding whether the anterior or posterior surgical approach is optimal for patients with cervical spondylotic myelopathy (CSM).Summary of background data
The optimal surgical approach to treat CSM remains debated with varying opinions favoring anterior versus posterior surgical approaches. We present an analysis of a prospective observational multicenter study examining outcomes of surgical treatment for CSM.Methods
A total of 278 subjects from 12 sites in North America received anterior/posterior or combined surgery at the discretion of the surgeon. This study focused on subjects who had either anterior or posterior surgery (n = 264, follow-up rate, 87%). Outcome measures included the modified Japanese Orthopedic Assessment scale, the Nurick scale, the Neck Disability Index, and the Short-Form 36 (SF-36) Health Survey version 2 Physical and Mental Component Scores.Results
One hundred and sixty-nine patients were treated anteriorly and 95 underwent posterior surgery. Anterior surgical cases were younger and had less severe myelopathy as assessed by mJOA and Nurick scores. There were no baseline differences in Neck Disability Index or SF-36 between the anterior and posterior cases. Improvement in the mJOA was significantly lower in the anterior group than posterior group (2.47 vs. 3.62, respectively, P < 0.01), although the groups started at different levels of baseline impairment. The extent of improvement in the Nurick Scale, Neck Disability Index, SF-36 version 2 Physical Component Score, and SF-36 version 2 Mental Component Score did not differ between the groups.Conclusion
Patients with CSM show significant improvements in several health-related outcome measures with either anterior or posterior surgery. Importantly, patients treated with anterior techniques were younger, with less severe impairment and more focal pathology. We demonstrate for the first time that, when patient and disease factors are controlled for, anterior and posterior surgical techniques have equivalent efficacy in the treatment of CSM.Level of evidence
3.Item Open Access Are the Arbeitsgemeinschaft Für Osteosynthesefragen (AO) Principles for Long Bone Fractures Applicable to 3-Column Osteotomy to Reduce Rod Fracture Rates?(Clinical spine surgery, 2022-06) Virk, Sohrab; Lafage, Renaud; Bess, Shay; Shaffrey, Christopher; Kim, Han J; Ames, Christopher; Burton, Doug; Gupta, Munish; Smith, Justin S; Eastlack, Robert; Klineberg, Eric; Mundis, Gregory; Schwab, Frank; Lafage, Virginie; International Spine Study GroupObjective
The aim was to determine whether applying Arbeitsgemeinschaft für Osteosynthesefragen (AO) principles for external fixation of long bone fracture to patients with a 3-column osteotomy (3CO) would be associated with reduced rod fracture (RF) rates.Summary of background data
AO dictate principles to follow when fixating long bone fractures: (1) decrease bone-rod distance; (2) increase the number of connecting rods; (3) increase the diameter of rods; (4) increase the working length of screws; (5) use multiaxial fixation. We hypothesized that applying these principles to patients undergoing a 3CO reduces the rate of RF.Methods
Patients were categorized as having RF versus no rod fracture (non-RF). Details on location and type of instrumentation were collected. Dedicated software was used to calculate the distance between osteotomy site and adjacent pedicle screws, angle between screws and the distance between the osteotomy site and rod. Classic sagittal spinopelvic parameters were evaluated.Results
The study included 170 patients (34=RF, 136=non-RF). There was no difference in age (P=0.224), sagittal vertical axis correction (P=0.287), or lumbar lordosis correction (P=0.36). There was no difference in number of screws cephalad (P=0.62) or caudal (P=0.31) to 3CO site. There was a lower rate of RF for patients with >2 rods versus 2 rods (P<0.001). Patients with multiplanar rod fixation had a lower rod fracture rate (P=0.01). For patients with only 2 rods (N=68), the non-RF cohort had adjacent screws that trended to have less angulation to each other (P=0.06) and adjacent screws that had a larger working length (P=0.03).Conclusions
A portion of AO principles can be applied to 3CO to reduce RF rates. Placing more rods around a 3CO site, placing rods in multiple planes, and placing adjacent screws with a larger working length around the 3CO site is associated with lower RF rates.Item Open Access Artificial intelligence clustering of adult spinal deformity sagittal plane morphology predicts surgical characteristics, alignment, and outcomes.(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, 2021-08) Durand, Wesley M; Lafage, Renaud; Hamilton, D Kojo; Passias, Peter G; Kim, Han Jo; Protopsaltis, Themistocles; Lafage, Virginie; Smith, Justin S; Shaffrey, Christopher; Gupta, Munish; Kelly, Michael P; Klineberg, Eric O; Schwab, Frank; Gum, Jeffrey L; Mundis, Gregory; Eastlack, Robert; Kebaish, Khaled; Soroceanu, Alex; Hostin, Richard A; Burton, Doug; Bess, Shay; Ames, Christopher; Hart, Robert A; Daniels, Alan H; International Spine Study Group (ISSG)Purpose
AI algorithms have shown promise in medical image analysis. Previous studies of ASD clusters have analyzed alignment metrics-this study sought to complement these efforts by analyzing images of sagittal anatomical spinopelvic landmarks. We hypothesized that an AI algorithm would cluster preoperative lateral radiographs into groups with distinct morphology.Methods
This was a retrospective review of a multicenter, prospectively collected database of adult spinal deformity. A total of 915 patients with adult spinal deformity and preoperative lateral radiographs were included. A 2 × 3, self-organizing map-a form of artificial neural network frequently employed in unsupervised classification tasks-was developed. The mean spine shape was plotted for each of the six clusters. Alignment, surgical characteristics, and outcomes were compared.Results
Qualitatively, clusters C and D exhibited only mild sagittal plane deformity. Clusters B, E, and F, however, exhibited marked positive sagittal balance and loss of lumbar lordosis. Cluster A had mixed characteristics, likely representing compensated deformity. Patients in clusters B, E, and F disproportionately underwent 3-CO. PJK and PJF were particularly prevalent among clusters A and E. Among clusters B and F, patients who experienced PJK had significantly greater positive sagittal balance than those who did not.Conclusions
This study clustered preoperative lateral radiographs of ASD patients into groups with highly distinct overall spinal morphology and association with sagittal alignment parameters, baseline HRQOL, and surgical characteristics. The relationship between SVA and PJK differed by cluster. This study represents significant progress toward incorporation of computer vision into clinically relevant classification systems in adult spinal deformity.Level of evidence iv
Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.Item Open Access Artificial Intelligence Models Predict Operative Versus Nonoperative Management of Patients with Adult Spinal Deformity with 86% Accuracy.(World neurosurgery, 2020-09) Durand, Wesley M; Daniels, Alan H; Hamilton, David K; Passias, Peter; Kim, Han Jo; Protopsaltis, Themistocles; LaFage, Virginie; Smith, Justin S; Shaffrey, Christopher; Gupta, Munish; Klineberg, Eric; Schwab, Frank; Burton, Doug; Bess, Shay; Ames, Christopher; Hart, Robert; International Spine Study GroupObjective
Patients with ASD show complex and highly variable disease. The decision to manage patients operatively is largely subjective and varies based on surgeon training and experience. We sought to develop models capable of accurately discriminating between patients receiving operative versus nonoperative treatment based only on baseline radiographic and clinical data at enrollment.Methods
This study was a retrospective analysis of a multicenter consecutive cohort of patients with ASD. A total of 1503 patients were included, divided in a 70:30 split for training and testing. Patients receiving operative treatment were defined as those undergoing surgery up to 1 year after their baseline visit. Potential predictors included available demographics, past medical history, patient-reported outcome measures, and premeasured radiographic parameters from anteroposterior and lateral films. In total, 321 potential predictors were included. Random forest, elastic net regression, logistic regression, and support vector machines (SVMs) with radial and linear kernels were trained.Results
Of patients in the training and testing sets, 69.0% (n = 727) and 69.1% (n = 311), respectively, received operative management. On evaluation with the testing dataset, performance for SVM linear (area under the curve =0.910), elastic net (0.913), and SVM radial (0.914) models was excellent, and the logistic regression (0.896) and random forest (0.830) models performed very well for predicting operative management of patients with ASD. The SVM linear model showed 86% accuracy.Conclusions
This study developed models showing excellent discrimination (area under the curve >0.9) between patients receiving operative versus nonoperative management, based solely on baseline study enrollment values. Future investigations may evaluate the implementation of such models for decision support in the clinical setting.Item Open Access Assessment of Impact of Long-Cassette Standing X-Rays on Surgical Planning for Cervical Pathology: An International Survey of Spine Surgeons.(Neurosurgery, 2016-05) Ramchandran, Subaraman; Smith, Justin S; Ailon, Tamir; Klineberg, Eric; Shaffrey, Christopher; Lafage, Virginie; Schwab, Frank; Bess, Shay; Daniels, Alan; Scheer, Justin K; Protopsaltis, Themi S; Arnold, Paul; Haid, Regis W; Chapman, Jens; Fehlings, Michael G; Ames, Christopher P; AOSpine North America, International Spine Study GroupBackground
Understanding the role of regional segments of the spine in maintaining global balance has garnered significant attention recently. Long-cassette radiographs (LCR) are necessary to evaluate global spinopelvic alignment. However, it is unclear how LCRs impact operative decision-making for cervical spine pathology.Objective
To evaluate whether the addition of LCRs results in changes to respondents' operative plans compared to standard imaging of the involved cervical spine in an international survey of spine surgeons.Methods
Fifteen cases (5 control cases with normal and 10 test cases with abnormal global alignment) of cervical pathology were presented online with a vignette and cervical imaging. Surgeons were asked to select a surgical plan from 6 options, ranging from the least (1 point) to most (6 points) extensive. Cases were then reordered and presented again with LCRs and the same surgical plan question.Results
One hundred fifty-seven surgeons completed the survey, of which 79% were spine fellowship trained. The mean response scores for surgical plan increased from 3.28 to 4.0 (P = .003) for test cases with the addition of LCRs. However, no significant changes (P = .10) were identified for the control cases. In 4 of the test cases with significant mid thoracic kyphosis, 29% of participants opted for the more extensive surgical options of extension to the mid and lower thoracic spine when they were provided with cervical imaging only, which significantly increased to 58.3% upon addition of LCRs.Conclusion
In planning for cervical spine surgery, surgeons should maintain a low threshold for obtaining LCRs to assess global spinopelvic alignment.Item Open Access Assessment of Patient Outcomes and Proximal Junctional Failure Rate of Adult Spinal Deformity Patients Undergoing Caudal Extension of Previous Spinal Fusion.(World neurosurgery, 2020-04-16) Daniels, Alan H; Reid, Daniel BC; Durand, Wesley M; Line, Breton; Passias, Peter; Kim, Han Jo; Protopsaltis, Themistocles; LaFage, Virginie; Smith, Justin S; Shaffrey, Christopher; Gupta, Munish; Klineberg, Eric; Schwab, Frank; Burton, Doug; Bess, Shay; Ames, Christopher; Hart, Robert A; International Spine Study GroupOBJECT:This case series examined patients undergoing caudal extension of prior fusion without alteration of the prior UIV to assess patient outcomes and rates of PJK/PJF. METHODS:Patients eligible for 2-year minimum follow-up undergoing caudal extension of prior fusion with unchanged UIVs were identified. These patients were evaluated for PJK/PJF, and patient reported outcomes were recorded. RESULTS:In total, 40 patients were included. Mean follow-up duration was 2.2 years (SD 0.3). Patients in this cohort had poor preoperative sagittal alignment (PI-LL 26.7°, TPA 29.0°, SVA 93.4mm) and achieved substantial sagittal correction (ΔSVA -62.2mm, ΔPI-LL -19.8°, ΔTPA -11.1°) following caudal extension surgery. At final follow-up, there was a 0% rate of PJF among patients undergoing caudal extension of previous fusion without creation of a new UIV, but 27.5% of patients experienced PJK. Patients experienced significant improvement in both ODI and SRS-22r total score at 2-years post-operatively (p<0.05). In total, 7.5% (n=3) of patients underwent further revision, at an average of 1.1 years (SD 0.54) after the surgery with unaltered UIV. All three of these patients underwent revision for rod fracture with no revisions for PJK/PJF. CONCLUSIONS:Patients undergoing caudal extension of previous fusions for sagittal alignment correction have high rates of clinical success, low revision surgery rates, and very low rates of PJF. Minimizing repetitive tissue trauma at the UIV may result in decreased PJF risk, as the PJF rate in this cohort of unaltered UIV patients is below historical PJF rates of patients undergoing sagittal balance correction.Item Open Access At What Point Should the Thoracolumbar Region Be Addressed in Patients Undergoing Corrective Cervical Deformity Surgery?(Spine, 2021-10) Passias, Peter G; Pierce, Katherine E; Naessig, Sara; Ahmad, Waleed; Passfall, Lara; Lafage, Renaud; Lafage, Virginie; Kim, Han Jo; Daniels, Alan; Eastlack, Robert; Klineberg, Eric; Line, Breton; Mummaneni, Praveen; Hart, Robert; Burton, Douglas; Bess, Shay; Schwab, Frank; Shaffrey, Christopher; Smith, Justin S; Ames, Christopher P; International Spine Study GroupStudy design
Retrospective cohort study.Objective
The aim of this study was to investigate the impact of cervical to thoracolumbar ratios on poor outcomes in cervical deformity (CD) corrective surgery.Summary of background data
Consideration of distal regional and global alignment is a critical determinant of outcomes in CD surgery. For operative CD patients, it is unknown whether certain thoracolumbar parameters play a significant role in poor outcomes and whether addressing such parameters is warranted.Methods
Included: surgical CD patients (C2-C7 Cobb >10°, cervical lordosis [CL] >10°, C2-C7 sagittal vertical axis (cSVA) >4 cm, or chin-brow vertical angle >25°) with baseline and 1-year data. Patients were assessed for ratios of preop cervical and global parameters including: C2 Slope/T1 slope, T1 slope minus C2-C7 lordosis (TS-CL)/mismatch between pelvic incidence and lumbar lordosis (PI-LL), cSVA/sagittal vertical axis (SVA). Deformity classification ratios of cervical (Ames-ISSG) to spinopelvic (SRS-Schwab) were investigated: cSVA modifier/SVA modifier, TS-CL modifier/PI-LL modifier. Cervical to thoracic ratios included C2-C7 lordosis/T4-T12 kyphosis. Correlations assessed the relationship between ratios and poor outcomes (major complication, reoperation, distal junctional kyphosis (DJK), or failure to meet minimal clinically important difference [MCID]). Decision tree analysis through multiple iterations of multivariate regressions assessed cut-offs for ratios for acquiring suboptimal outcomes.Results
A total of 110 CD patients were included (61.5 years, 66% F, 28.8 kg/m2). Mean preoperative radiographic ratios calculated: C2 slope/T1 slope of 1.56, TS-CL/PI-LL of 11.1, cSVA/SVA of 5.4, CL/thoracic kyphosis (TK) of 0.26. Ames-ISSG and SRS-Schwab modifier ratios: cSVA/SVA of 0.1 and TS-CL/PI-LL of 0.35. Pearson correlations demonstrated a relationship between major complications and baseline TS-CL/PI-LL, Ames TS-CL/Schwab PI-LL modifiers, and the CL/TK ratios (P < 0.050). Reoperation had significant correlation with TS-CL/PI-LL and cSVA/SVA ratios. Postoperative DJK correlated with C2 slope/T1 slope and CL/TK ratios. Not meeting MCID for Neck Disability Index (NDI) correlated with CL/TK ratio and not meeting MCID for EQ5D correlated with Ames TS-CL/Schwab PI-LL.Conclusion
Consideration of cervical to global alignment is a critical determinant of outcomes in CD corrective surgery. Key ratios of cervical to global alignment correlate with suboptimal clinical outcomes. A larger cervical lordosis to TK predicted postoperative complication, DJK, and not meeting MCID for NDI.Level of Evidence: 4.Item Open Access Author Correction: Sagittal age-adjusted score (SAAS) for adult spinal deformity (ASD) more effectively predicts surgical outcomes and proximal junctional kyphosis than previous classifications.(Spine deformity, 2023-03) Lafage, Renaud; Smith, Justin S; Elysee, Jonathan; Passias, Peter; Bess, Shay; Klineberg, Eric; Kim, Han Jo; Shaffrey, Christopher; Burton, Douglas; Hostin, Richard; Mundis, Gregory; Ames, Christopher; Schwab, Frank; Lafage, Virginie; International Spine Study Group (ISSG)In Fig. 4 of this article signs for points associated in all 3 components are incorrect and should be reversed, e.g. + 2 should be − 2 and vise versa; Fig. 4 should have appeared as shown below. The original article has been corrected