Browsing by Author "Williamson, Tyler K"
Now showing 1 - 16 of 16
Results Per Page
Sort Options
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 Are We Focused on the Wrong Early Postoperative Quality Metrics? Optimal Realignment Outweighs Perioperative Risk in Adult Spinal Deformity Surgery.(Journal of clinical medicine, 2023-08) Passias, Peter G; Williamson, Tyler K; Mir, Jamshaid M; Smith, Justin S; Lafage, Virginie; Lafage, Renaud; Line, Breton; Daniels, Alan H; Gum, Jeffrey L; Schoenfeld, Andrew J; Hamilton, David Kojo; Soroceanu, Alex; Scheer, Justin K; Eastlack, Robert; Mundis, Gregory M; Diebo, Bassel; Kebaish, Khaled M; Hostin, Richard A; Gupta, Munish C; Kim, Han Jo; Klineberg, Eric O; Ames, Christopher P; Hart, Robert A; Burton, Douglas C; Schwab, Frank J; Shaffrey, Christopher I; Bess, Shay; On Behalf Of The International Spine Study GroupBackground
While reimbursement is centered on 90-day outcomes, many patients may still achieve optimal, long-term outcomes following adult spinal deformity (ASD) surgery despite transient short-term complications.Objective
Compare long-term clinical success and cost-utility between patients achieving optimal realignment and suboptimally aligned peers.Study design/setting
Retrospective cohort study of a prospectively collected multicenter database.Methods
ASD patients with two-year (2Y) data included. Groups were propensity score matched (PSM) for age, frailty, body mass index (BMI), Charlson Comorbidity Index (CCI), and baseline deformity. Optimal radiographic criteria are defined as meeting low deformity in all three (Scoliosis Research Society) SRS-Schwab parameters or being proportioned in Global Alignment and Proportionality (GAP). Cost-per-QALY was calculated for each time point. Multivariable logistic regression analysis and ANCOVA (analysis of covariance) adjusting for baseline disability and deformity (pelvic incidence (PI), pelvic incidence minus lumbar lordosis (PI-LL)) were used to determine the significance of surgical details, complications, clinical outcomes, and cost-utility.Results
A total of 930 patients were considered. Following PSM, 253 "optimal" (O) and 253 "not optimal" (NO) patients were assessed. The O group underwent more invasive procedures and had more levels fused. Analysis of complications by two years showed that the O group suffered less overall major (38% vs. 52%, p = 0.021) and major mechanical complications (12% vs. 22%, p = 0.002), and less reoperations (23% vs. 33%, p = 0.008). Adjusted analysis revealed O patients more often met MCID (minimal clinically important difference) in SF-36 PCS, SRS-22 Pain, and Appearance. Cost-utility-adjusted analysis determined that the O group generated better cost-utility by one year and maintained lower overall cost and costs per QALY (both p < 0.001) at two years.Conclusions
Fewer late complications (mechanical and reoperations) are seen in optimally aligned patients, leading to better long-term cost-utility overall. Therefore, the current focus on avoiding short-term complications may be counterproductive, as achieving optimal surgical correction is critical for long-term success.Item Open Access Changes in health-related quality of life measures associated with degree of proximal junctional kyphosis.(Spine deformity, 2023-05) Passias, Peter G; Frangella, Nicholas J; Williamson, Tyler K; Moattari, Kevin A; Lafage, Renaud; Lafage, Virginie; Smith, Justin S; Kebaish, Khaled M; Burton, Douglas C; Hart, Robert A; Ames, Christopher P; Bess, Shay; Shaffrey, Christopher I; Schwab, Frank J; International Spine Study GroupPurpose
To explore the changes in health-related quality of life parameters observed in patients experiencing varying degrees of proximal junctional kyphosis following corrective adult spinal deformity fusions.Methods
Inclusion: adult spinal deformity patients > 18 y/o, undergoing spinal fusion. PJK: ≥ 10° measure of the sagittal Cobb angle between the inferior endplate of the UIV and the superior endplate of the UIV + 2. Severe PJK: > 28° PJK. Mild PJK: ≥ 10oand ≤ 28°. ANOVA, followed by ANCOVA, compared the change in HRQoLs between time points (BL, 1Y, 2Y) among PJK groups. Correlation-related change in PJK and change in HRQoL for mild and severe groups.Results
969 patients (age: 64.5 y/o,75% F, posterior levels fused:12.3) were studied. 59% no PJK, 32% mild PJK, 9% severe PJK. No differences in HRQoLs were seen between no PJK and PJK groups at baseline, one year, and 2 years. Adjusted analysis revealed Severe PJK patients improved less in SRS-22 Satisfaction (NoPJK: 1.6, MildPJK: 1.6, SeverePJK: 1.0; p = 0.022) scores at 2 years. Linear regression analysis only found clinical improvement in SRS-22 Satisfaction to correlate with the change of the PJK angle by 2 years (R = 0.176, P = 0.008). No other HRQoL metric correlated with either the incidence of PJK or the change in the PJK angle by one or 2 years.Conclusions
These results maintain that patients presenting with and without proximal junctional kyphosis report similar health-related qualities of life following corrective adult spinal deformity surgery, and SRS-22 Satisfaction may be a clinical correlate to the degree of PJK. Rather than proving proximal junctional kyphosis to have a minimal clinical impact overall on HRQoL metrics, these data suggest that future analysis of this phenomenon requires different assessments.Level of evidence
Level of evidence: III.Item Open Access Compensation from mild and severe cases of early proximal junctional kyphosis may manifest as progressive cervical deformity at two year follow-up.(Spine deformity, 2023-12) Passias, Peter G; Naessig, Sara; Williamson, Tyler K; Lafage, Renaud; Lafage, Virginie; Smith, Justin S; Gupta, Munish C; Klineberg, Eric; Burton, Douglas C; Ames, Christopher; Bess, Shay; Shaffrey, Christopher; Schwab, Frank J; International Spine Study Group (ISSG)Background
Postoperative reciprocal changes (RC) in the cervical spine associated with varying factors of proximal junctional kyphosis (PJK) following fusions of the thoracopelvic spine are poorly understood.Purpose
Explore reciprocal changes in the cervical spine associated with varying factors (severity, progression, patient age) of PJK in patients undergoing adult spinal deformity (ASD) correction.Patients and methods
Retrospective review of a multicenter ASD database.Inclusion
ASD patients > 18 y/o, undergoing fusions from the thoracic spine (UIV: T6-T12) to the pelvis with two-year radiographic data. ASD was defined as: Coronal Cobb angle ≥ 20°, Sagittal Vertical Axis ≥ 5 cm, Pelvic Tilt ≥ 25°, and/or Thoracic Kyphosis ≥ 60°. PJK was defined as a ≥ 10° measure of the sagittal Cobb angle between the inferior endplate of the UIV and the superior endplate of the UIV + 2. Patients were grouped by mild (M; 10°-20°) and severe (S; > 20°) PJK at one year. Propensity Score Matching (PSM) controlled for CCI, age, PI and UIV. Unpaired and paired t test analyses determined difference between RC parameters and change between time points. Pearson bi-variate correlations analyzed associations between RC parameters (T4-T12, TS-CL, cSVA, C2-Slope, and T1-Slope) and PJK descriptors.Results
284 ASD patients (UIV: T6: 1.1%; T7: 0.7%; T8: 4.6%; T9: 9.9%; T10: 58.8%; T11: 19.4%; T12: 5.6%) were studied. PJK analysis consisted of 182 patients (Mild = 91 and Severe = 91). Significant difference between M and S groups were observed in T4-T12 Δ1Y(- 16.8 v - 22.8, P = 0.001), TS-CLΔ1Y(- 0.6 v 2.8, P = 0.037), cSVAΔ1Y(- 1.8 v 1.9, P = 0.032), and C2 slopeΔ1Y(- 1.6 v 2.3, P = 0.022). By two years post-op, all changes in cervical alignment parameters were similar between mild and severe groups. Correlation between age and cSVAΔ1Y(R = 0.153, P = 0.034) was found. Incidence of severe PJK was found to correlate with TS-CLΔ1Y(R = 0.142, P = 0.049), cSVAΔ1Y(R = 0.171, P = 0.018), C2SΔ1Y(R = 0.148, P = 0.040), and T1SΔ2Y(R = 0.256, P = 0.003).Conclusions
Compensation within the cervical spine differed between individuals with mild and severe PJK at one year postoperatively. However, similar levels of pathologic change in cervical alignment parameters were seen by two years, highlighting the progression of cervical compensation due to mild PJK over time. These findings provide greater evidence for the development of cervical deformity in individuals presenting with proximal junctional kyphosis.Item Open Access Contemporary utilization of three-column osteotomy techniques in a prospective complex spinal deformity multicenter database: implications on full-body alignment and perioperative course.(Spine deformity, 2024-06) Williamson, Tyler K; Mir, Jamshaid M; Smith, Justin S; Lafage, Virginie; Lafage, Renaud; Line, Breton; Diebo, Bassel G; Daniels, Alan H; Gum, Jeffrey L; Hamilton, D Kojo; Scheer, Justin K; Eastlack, Robert; Demetriades, Andreas K; Kebaish, Khaled M; Lewis, Stephen; Lenke, Lawrence G; Hostin, Richard A; Gupta, Munish C; Kim, Han Jo; Ames, Christopher P; Burton, Douglas C; Shaffrey, Christopher I; Klineberg, Eric O; Bess, Shay; Passias, Peter G; International Spine Study GroupBackground
Research has focused on the increased correction from a three-column osteotomy (3CO) during adult spinal deformity (ASD) surgery. However, an in-depth analysis on the performance of a 3CO in a cohort of complex spinal deformity cases has not been described.Study design/setting
This is a retrospective study on a prospectively enrolled, complex ASD database.Purpose
This study aimed to determine if three-column osteotomies demonstrate superior benefit in correction of complex sagittal deformity at the cost of increased perioperative complications.Methods
Surgical complex adult spinal deformity patients were included and grouped into thoracolumbar 3COs compared to those who did not have a 3CO (No 3CO) (remaining cohort). Rigid deformity was defined as ΔLL less than 33% from standing to supine. Severe deformity was defined as global (SVA > 70 mm) or C7-PL > 70 mm, or lumbopelvic (PI-LL > 30°). Means comparison tests assessed correction by 3CO grade/location. Multivariate analysis controlling for baseline deformity evaluated outcomes up to six weeks compared to No 3CO.Results
648 patients were included (Mean age 61 ± 14.6 years, BMI 27.55 ± 5.8 kg/m2, levels fused: 12.6 ± 3.8). 126 underwent 3CO, a 20% higher usage than historical cohorts. 3COs were older, frail, and more likely to undergo revision (OR 5.2, 95% CI [2.6-10.6]; p < .001). 3COs were more likely to present with both severe global/lumbopelvic deformity (OR 4), 62.4% being rigid. 3COs had greater use of secondary rods (OR 4st) and incurred 4 times greater risk for: massive blood loss (> 3500 mL), longer LOS, SICU admission, perioperative wound and spine-related complications, and neurologic complications when performed below L3. 3COs had similar HRQL benefit, but higher perioperative opioid use. Mean segmental correction increased by grade (G3-21; G4-24; G5-27) and was 4 × greater than low-grade osteotomies, especially below L3 (OR 12). 3COs achieved 2 × greater spinopelvic correction. Higher grades properly distributed lordosis 50% of the time except L5. Pelvic compensation and non-response were relieved more often with increasing grade, with greater correction in all lower extremity parameters (p < .01). Due to the increased rate of complications, 3COs trended toward higher perioperative cost ($42,806 vs. $40,046, p = .086).Conclusion
Three-column osteotomy usage in contemporary complex spinal deformities is generally limited to more disabled individuals undergoing the most severe sagittal and coronal realignment procedures. While there is an increased perioperative cost and prolongation of length of stay with usage, these techniques represent the most powerful realignment techniques available with a dramatic impact on normalization at operative levels and reciprocal changes.Item Open Access Cost Benefit of Implementation of Risk Stratification Models for Adult Spinal Deformity Surgery.(Global Spine J, 2023-12-11) Passias, Peter G; Williamson, Tyler K; Kummer, Nicholas A; Pellisé, Ferran; Lafage, Virginie; Lafage, Renaud; Serra-Burriel, Miguel; Smith, Justin S; Line, Breton; Vira, Shaleen; Gum, Jeffrey L; Haddad, Sleiman; Sánchez Pérez-Grueso, Francisco Javier; Schoenfeld, Andrew J; Daniels, Alan H; Chou, Dean; Klineberg, Eric O; Gupta, Munish C; Kebaish, Khaled M; Kelly, Michael P; Hart, Robert A; Burton, Douglas C; Kleinstück, Frank; Obeid, Ibrahim; Shaffrey, Christopher I; Alanay, Ahmet; Ames, Christopher P; Schwab, Frank J; Hostin, Richard A; Bess, Shay; International Spine Study GroupSTUDY DESIGN/SETTING: Retrospective cohort study. OBJECTIVE: Assess the extent to which defined risk factors of adverse events are drivers of cost-utility in spinal deformity (ASD) surgery. METHODS: ASD patients with 2-year (2Y) data were included. Tertiles were used to define high degrees of frailty, sagittal deformity, blood loss, and surgical time. Cost was calculated using the Pearl Diver registry and cost-utility at 2Y was compared between cohorts based on the number of risk factors present. Statistically significant differences in cost-utility by number of baseline risk factors were determined using ANOVA, followed by a generalized linear model, adjusting for clinical site and surgeon, to assess the effects of increasing risk score on overall cost-utility. RESULTS: By 2 years, 31% experienced a major complication and 23% underwent reoperation. Patients with ≤2 risk factors had significantly less major complications. Patients with 2 risk factors improved the most from baseline to 2Y in ODI. Average cost increased by $8234 per risk factor (R2 = .981). Cost-per-QALY at 2Y increased by $122,650 per risk factor (R2 = .794). Adjusted generalized linear model demonstrated a significant trend between increasing risk score and increasing cost-utility (r2 = .408, P < .001). CONCLUSIONS: The number of defined patient-specific and surgical risk factors, especially those with greater than two, were associated with increased index surgical costs and diminished cost-utility. Efforts to optimize patient physiology and minimize surgical risk would likely reduce healthcare expenditures and improve the overall cost-utility profile for ASD interventions.Level of evidence: III.Item Open Access Efficacy of Varying Surgical Approaches on Achieving Optimal Alignment in Adult Spinal Deformity Surgery.(Spine, 2023-07) Passias, Peter G; Ahmad, Waleed; Williamson, Tyler K; Lebovic, Jordan; Kebaish, Khaled; Lafage, Renaud; Lafage, Virginie; Line, Breton; Schoenfeld, Andrew J; Diebo, Bassel G; Klineberg, Eric O; Kim, Han Jo; Ames, Christopher P; Daniels, Alan H; Smith, Justin S; Shaffrey, Christopher I; Burton, Douglas C; Hart, Robert A; Bess, Shay; Schwab, Frank J; Gupta, Munish C; International Spine Study GroupBackground
The Roussouly, SRS-Schwab, and GAP classifications define alignment by spinal shape and deformity severity. The efficacy of different surgical approaches and techniques to successfully achieve these goals is not well understood.Purpose
Identify the impact of surgical approach and/or technique on meeting complex realignment goals in adult spinal deformity(ASD) corrective-surgery.Study design/setting
Retrospective.Methods
Included: ASD patients fused to pelvis with two-year(2Y) data. Patients were categorized by: 1)Roussouly: matching current and theoretical spinal shapes; 2)improving in SRS-Schwab modifiers(0, +, ++); 3)improving GAP Proportionality by 2Y. ANCOVA and multivariable logistic regression analyses controlling for age, levels fused, baseline deformity, and three-column osteotomy usage compared the effect of different surgical approaches, interbody and osteotomy use on meeting realignment goals.Results
693 ASD patients were included. By surgical approach, 65.7% were posterior-only and 34.3% underwent anterior-posterior(AP) approach with 76% receiving an osteotomy(21.8% 3CO). By 2Y, 34% matched Roussouly, 58% improved in GAP, 45% in SRS-Schwab PT, 62% SVA, and 70% PI-LL. Combined approaches were most effective for improvement in PT(OR: 1.7,[1.1-2.5]) and GAP(OR: 2.2,[1.5-3.2]). Specifically, ALIFs below L3 demonstrated higher rates of improvement versus TLIFs in Roussouly(OR: 1.7, [1.1-2.5]) and GAP(OR: 1.9, [1.3-2.7]). Patients undergoing PSO at L3 or L4 were more likely to improve in PT(OR: 2.0,[1.0-5.2]) and PI-LL(OR: 3.8[1.4-9.8]). Clinically, patients undergoing combined approach demonstrated higher rates of meeting SCB in ODI by 2Y while minimizing rates of PJF, most often with an ALIF at L5-S1(ODI-SCB: OR: 1.4,[1.1-2.0];PJF: OR: 0.4,[0.2-0.8]).Conclusions
Among patients undergoing ASD realignment, optimal lumbar shape and proportion can be achieved more often with a combined approach. While TLIFs incorporating a three-column osteotomy at L3 and L4 can restore lordosis and normalize pelvic compensation, ALIFs at L5-S1 were most likely to achieve complex realignment goals with an added clinical benefit and mitigation of junctional failure.Item Open Access Evolution of Adult Cervical Deformity Surgery Clinical and Radiographic Outcomes Based on a Multicenter Prospective Study: Are Behaviors and Outcomes Changing With Experience?(Spine, 2022-11) Passias, Peter G; Krol, Oscar; Moattari, Kevin; Williamson, Tyler K; Lafage, Virginie; Lafage, Renaud; Kim, Han Jo; Daniels, Alan; Diebo, Bassel; Protopsaltis, Themistocles; Mundis, Gregory; Kebaish, Khaled; Soroceanu, Alexandra; Scheer, Justin; Hamilton, D Kojo; Klineberg, Eric; Schoenfeld, Andrew J; Vira, Shaleen; Line, Breton; Hart, Robert; Burton, Douglas C; Schwab, Frank A; Shaffrey, Christopher; Bess, Shay; Smith, Justin S; Ames, Christopher P; International Spine Study GroupStudy design
Retrospective cohort study.Objective
Assess changes in outcomes and surgical approaches for adult cervical deformity surgery over time.Summary of background data
As the population ages and the prevalence of cervical deformity increases, corrective surgery has been increasingly seen as a viable treatment. Dramatic surgical advancements and expansion of knowledge on this procedure have transpired over the years, but the impact on cervical deformity surgery is unknown.Materials and methods
Adult cervical deformity patients (18 yrs and above) with complete baseline and up to the two-year health-related quality of life and radiographic data were included. Descriptive analysis included demographics, radiographic, and surgical details. Patients were grouped into early (2013-2014) and late (2015-2017) by date of surgery. Univariate and multivariable regression analyses were used to assess differences in surgical, radiographic, and clinical outcomes over time.Results
A total of 119 cervical deformity patients met the inclusion criteria. Early group consisted of 72 patients, and late group consisted of 47. The late group had a higher Charlson Comorbidity Index (1.3 vs. 0.72), more cerebrovascular disease (6% vs. 0%, both P <0.05), and no difference in age, frailty, deformity, or cervical rigidity. Controlling for baseline deformity and age, late group underwent fewer three-column osteotomies [odds ratio (OR)=0.18, 95% confidence interval (CI): 0.06-0.76, P =0.014]. At the last follow-up, late group had less patients with: a moderate/high Ames horizontal modifier (71.7% vs. 88.2%), and overcorrection in pelvic tilt (4.3% vs. 18.1%, both P <0.05). Controlling for baseline deformity, age, levels fused, and three-column osteotomies, late group experienced fewer adverse events (OR=0.15, 95% CI: 0.28-0.8, P =0.03), and neurological complications (OR=0.1, 95% CI: 0.012-0.87, P =0.03).Conclusion
Despite a population with greater comorbidity and associated risk, outcomes remained consistent between early and later time periods, indicating general improvements in care. The later cohort demonstrated fewer three-column osteotomies, less suboptimal realignments, and concomitant reductions in adverse events and neurological complications. This may suggest a greater facility with less invasive techniques.Item Open Access Highest Achievable Outcomes for Patients Undergoing Cervical Deformity Corrective Surgery by Frailty.(Neurosurgery, 2022-11) Passias, Peter G; Kummer, Nicholas; Williamson, Tyler K; Williamson, Tyler K; Moattari, Kevin; Lafage, Virginie; Lafage, Renaud; Kim, Han Jo; Daniels, Alan H; Gum, Jeffrey L; Diebo, Bassel G; Protopsaltis, Themistocles S; Mundis, Gregory M; Eastlack, Robert K; Soroceanu, Alexandra; Scheer, Justin K; Hamilton, D Kojo; Klineberg, Eric O; Line, Breton; Hart, Robert A; Burton, Douglas C; Mummaneni, Praveen; Chou, Dean; Park, Paul; Schwab, Frank J; Shaffrey, Christopher I; Bess, Shay; Ames, Christopher P; Smith, Justin S; International Spine Study GroupBackground
Frailty is influential in determining operative outcomes, including complications, in patients with cervical deformity (CD).Objective
To assess whether frailty status limits the highest achievable outcomes of patients with CD.Methods
Adult patients with CD with 2-year (2Y) data included. Frailty stratification: not frail (NF) <0.2, frail (F) 0.2 to 0.4, and severely frail (SF) >0.4. Analysis of covariance established estimated marginal means based on age, invasiveness, and baseline deformity, for improvement, deterioration, or maintenance in Neck Disability Index (NDI), Modified Japanese Orthopaedic Association (mJOA), and Numerical Rating Scale Neck Pain.Results
One hundred twenty-six patients with CD included 29 NF, 83 F, and 14 SF. The NF group had the highest rates of deterioration and lowest rates of improvement in cervical Sagittal Vertical Axis and horizontal gaze modifiers. Two-year improvements in NDI by frailty: NF: -11.2, F: -16.9, and SF: -14.6 ( P = .524). The top quartile of NF patients also had the lowest 1-year (1Y) NDI (7.0) compared with F (11.0) and SF (40.5). Between 1Y and 2Y, 7.9% of patients deteriorated in NDI, 71.1% maintained, and 21.1% improved. Between 1Y and 2Y, SF had the highest rate of improvement (42%), while NF had the highest rate of deterioration (18.5%).Conclusion
Although frail patients improved more often by 1Y, SF patients achieve most of their clinical improvement between 1 and 2Y. Frailty is associated with factors such as osteoporosis, poor alignment, neurological status, sarcopenia, and other medical comorbidities. Similarly, clinical outcomes can be affected by many factors (fusion status, number of pain generators within treated levels, integrity of soft tissues and bone, and deformity correction). Although accounting for such factors will ultimately determine whether frailty alone is an independent risk factor, these preliminary findings may suggest that frailty status affects the clinical outcomes and improvement after CD surgery.Item Open Access Patient-specific Cervical Deformity Corrections With Consideration of Associated Risk: Establishment of Risk Benefit Thresholds for Invasiveness Based on Deformity and Frailty Severity.(Clinical spine surgery, 2023-10) Passias, Peter G; Pierce, Katherine E; Williamson, Tyler K; Lebovic, Jordan; Schoenfeld, Andrew J; Lafage, Renaud; Lafage, Virginie; Gum, Jeffrey L; Eastlack, Robert; Kim, Han Jo; Klineberg, Eric O; Daniels, Alan H; Protopsaltis, Themistocles S; Mundis, Gregory M; Scheer, Justin K; Park, Paul; Chou, Dean; Line, Breton; Hart, Robert A; Burton, Douglas C; Bess, Shay; Schwab, Frank J; Shaffrey, Christopher I; Smith, Justin S; Ames, Christopher P; International Spine Study GroupStudy design/setting
This was a retrospective cohort study.Background
Little is known of the intersection between surgical invasiveness, cervical deformity (CD) severity, and frailty.Objective
The aim of this study was to investigate the outcomes of CD surgery by invasiveness, frailty status, and baseline magnitude of deformity.Methods
This study included CD patients with 1-year follow-up. Patients stratified in high deformity if severe in the following criteria: T1 slope minus cervical lordosis, McGregor's slope, C2-C7, C2-T3, and C2 slope. Frailty scores categorized patients into not frail and frail. Patients are categorized by frailty and deformity (not frail/low deformity; not frail/high deformity; frail/low deformity; frail/high deformity). Logistic regression assessed increasing invasiveness and outcomes [distal junctional failure (DJF), reoperation]. Within frailty/deformity groups, decision tree analysis assessed thresholds for an invasiveness cutoff above which experiencing a reoperation, DJF or not achieving Good Clinical Outcome was more likely.Results
A total of 115 patients were included. Frailty/deformity groups: 27% not frail/low deformity, 27% not frail/high deformity, 23.5% frail/low deformity, and 22.5% frail/high deformity. Logistic regression analysis found increasing invasiveness and occurrence of DJF [odds ratio (OR): 1.03, 95% CI: 1.01-1.05, P=0.002], and invasiveness increased with deformity severity (P<0.05). Not frail/low deformity patients more often met Optimal Outcome with an invasiveness index <63 (OR: 27.2, 95% CI: 2.7-272.8, P=0.005). An invasiveness index <54 for the frail/low deformity group led to a higher likelihood of meeting the Optimal Outcome (OR: 9.6, 95% CI: 1.5-62.2, P=0.018). For the frail/high deformity group, patients with a score <63 had a higher likelihood of achieving Optimal Outcome (OR: 4.8, 95% CI: 1.1-25.8, P=0.033). There was no significant cutoff of invasiveness for the not frail/high deformity group.Conclusions
Our study correlated increased invasiveness in CD surgery to the risk of DJF, reoperation, and poor clinical success. The thresholds derived for deformity severity and frailty may enable surgeons to individualize the invasiveness of their procedures during surgical planning to account for the heightened risk of adverse events and minimize unfavorable outcomes.Item Open Access Pelvic Nonresponse Following Treatment of Adult Spinal Deformity: Influence of Realignment Strategies on Occurrence.(Spine, 2023-05) Passias, Peter G; Pierce, Katherine E; Williamson, Tyler K; Krol, Oscar; Lafage, Renaud; Lafage, Virginie; Schoenfeld, Andrew J; Protopsaltis, Themistocles S; Vira, Shaleen; Line, Breton; Diebo, Bassel G; Ames, Christopher P; Kim, Han Jo; Smith, Justin S; Chou, Dean; Daniels, Alan H; Gum, Jeffrey L; Shaffrey, Christopher I; Burton, Douglas C; Kelly, Michael P; Klineberg, Eric O; Hart, Robert A; Bess, Shay; Schwab, Frank J; Gupta, Munish C; International Spine Study GroupPurpose
Despite adequate correction, the pelvis may fail to readjust, deemed pelvic nonresponse (PNR). To assess alignment outcomes [PNR, proximal junctional kyphosis (PJK), postoperative cervical deformity (CD)] following adult spinal deformity (ASD) surgery utilizing different realignment strategies.Materials and methods
ASD patients with two-year data were included. PNR defined as undercorrected in age-adjusted pelvic tilt (PT) at six weeks and maintained at two years. Patients classified by alignment utilities: (a) improvement in Scoliosis Research Society-Schwab sagittal vertical axis, (b) matching in age-adjusted pelvic incidence-lumbar lordosis, (c) matching in Roussouly, (d) aligning Global Alignment and Proportionality (GAP) score. Multivariable regression analyses, controlling for age, baseline deformity, and surgical factors, assessed rates of PNR, PJK, and CD development following realignment.Results
A total of 686 patients met the inclusion criteria. Rates of postoperative PJK and CD were not significant in the PNR group (both P >0.15). PNR patients less often met substantial clinical benefit in Oswestry Disability Index by two years [odds ratio: 0.6 (0.4-0.98)]. Patients overcorrected in age-adjusted pelvic incidence-lumbar lordosis, matching Roussouly, or proportioned in GAP at six weeks had lower rates of PNR (all P <0.001). Incremental addition of classifications led to 0% occurrence of PNR, PJK, and CD. Stratifying by baseline PT severity, Low and moderate deformity demonstrated the least incidence of PNR (7.7%) when proportioning in GAP at six weeks, while severe PT benefited most from matching in Roussouly (all P <0.05).Conclusions
Following ASD corrective surgery, 24.9% of patients showed residual pelvic malalignment. This occurrence was often accompanied by undercorrection of lumbopelvic mismatch and less improvement of pain. However, overcorrection in any strategy incurred higher rates of PJK. We recommend surgeons identify a middle ground using one, or more, of the available classifications to inform correction goals in this regard.Level of evidence
III.Item Open Access Persistent Lower Extremity Compensation for Sagittal Imbalance After Surgical Correction of Complex Adult Spinal Deformity: A Radiographic Analysis of Early Impact.(Operative neurosurgery (Hagerstown, Md.), 2024-02) Williamson, Tyler K; Williamson, Tyler K; Dave, Pooja; Mir, Jamshaid M; Smith, Justin S; Lafage, Renaud; Line, Breton; Diebo, Bassel G; Daniels, Alan H; Gum, Jeffrey L; Protopsaltis, Themistocles S; Hamilton, D Kojo; Soroceanu, Alex; Scheer, Justin K; Eastlack, Robert; Kelly, Michael P; Nunley, Pierce; Kebaish, Khaled M; Lewis, Stephen; Lenke, Lawrence G; Hostin, Richard A; Gupta, Munish C; Kim, Han Jo; Ames, Christopher P; Hart, Robert A; Burton, Douglas C; Shaffrey, Christopher I; Klineberg, Eric O; Schwab, Frank J; Lafage, Virginie; Chou, Dean; Fu, Kai-Ming; Bess, Shay; Passias, Peter G; International Spine Study GroupAchieving spinopelvic realignment during adult spinal deformity (ASD) surgery does not always produce ideal outcomes. Little is known whether compensation in lower extremities (LEs) plays a role in this disassociation. The objective is to analyze lower extremity compensation after complex ASD surgery, its effect on outcomes, and whether correction can alleviate these mechanisms. We included patients with complex ASD with 6-week data. LE parameters were as follows: sacrofemoral angle, knee flexion angle, and ankle flexion angle. Each parameter was ranked, and upper tertile was deemed compensation. Patients compensating and not compensating postoperatively were propensity score matched for body mass index, frailty, and T1 pelvic angle. Linear regression assessed correlation between LE parameters and baseline deformity, demographics, and surgical details. Multivariate analysis controlling for baseline deformity and history of total knee/hip arthroplasty evaluated outcomes. Two hundred and ten patients (age: 61.3 ± 14.1 years, body mass index: 27.4 ± 5.8 kg/m2, Charlson Comorbidity Index: 1.1 ± 1.6, 72% female, 22% previous total joint arthroplasty, 24% osteoporosis, levels fused: 13.1 ± 3.8) were included. At baseline, 59% were compensating in LE: 32% at hips, 39% knees, and 36% ankles. After correction, 61% were compensating at least one joint. Patients undercorrected postoperatively were less likely to relieve LE compensation (odds ratio: 0.2, P = .037). Patients compensating in LE were more often undercorrected in age-adjusted pelvic tilt, pelvic incidence, lumbar lordosis, and T1 pelvic angle and disproportioned in Global Alignment and Proportion (P < .05). Patients matched in sagittal age-adjusted score at 6 weeks but compensating in LE were more likely to develop proximal junctional kyphosis (odds ratio: 4.1, P = .009) and proximal junctional failure (8% vs 0%, P = .035) than those sagittal age-adjusted score-matched and not compensating in LE. Perioperative lower extremity compensation was a product of undercorrecting complex ASD. Even in age-adjusted realignment, compensation was associated with global undercorrection and junctional failure. Consideration of lower extremities during planning is vital to avoid adverse outcomes in perioperative course after complex ASD surgery.Item Open Access So Close yet So Far: The impact of undercorrection of cervical sagittal alignment during adult cervical deformity surgery - An Incremental correction analysis.(Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2024-10) Das, Ankita; Yung, Anthony; Onafowokan, Oluwatobi; Mir, Jamshaid; Fisher, Max R; Williamson, Tyler K; Cottrill, Ethan J; Buser, Zorica; Tretiakov, Peter S; Than, Khoi D; Shah, Neil V; Shaffrey, Christopher I; Passias, Peter GBackground
To compare degrees of cSVA correction and to theorize possible minimum and maximum thresholds of cSVA correction for patients to benefit clinically.Methods
657 operative ACD patients in a retrospective cohort study of a prospectively enrolled database with complete baseline and two year radiographic and HRQL data were examined. Patients were grouped into an optimally corrected cohort (OC; postop cSVA ≤ 4 cm) and an undercorrected cohort (UC; postop cSVA > 4 cm) based on postoperative radiographs.Results
265 patients met inclusion criteria (mean age 58.2 ± 11.4 years, BMI 28.9 ± 7.5, CCI 0.9 ± 1.3). 11.2 % of patients were UC, while 88.8 % of patients were OC. UC cohort experienced a significantly greater occurrence of radiographic complications (47.8 % v. 27.6 %, p = 0.046). UC also demonstrated a significantly greater rate of severe 6 M DJK (p < 0.001) and 1Y DJK (26.1 % v. 2.7 %, p < 0.001). In terms of HRQLs, the OC cohort demonstrated significantly greater 2Y EQ5D-Health values (76.9 v. 46.7, p = 0.012). Being UC was a significant predictor of moderate-high 1Y mJOA score (OR 3.0, CI 95 % 1.2-7.3, p = 0.015) Still, in terms of CIT, the threshold for DJF risk increased significantly (p = 0.026) when the cSVA were surgically corrected greater than 5 cm.Conclusion
Undercorrection of cSVA yielded worse clinical outcomes and posed a significant risk for radiographic complications. Although undercorrection does not seem to be efficacious, surgical correction beyond certain thresholds should still be respected as there is a risk for DJK on either end of the spectrum.Item Open Access The Additional Economic Burden of Frailty in Adult Cervical Deformity Patients Undergoing Surgical Intervention.(Spine, 2022-10) Passias, Peter G; Kummer, Nicholas A; Williamson, Tyler K; Ahmad, Waleed; Lebovic, Jordan; Lafage, Virginie; Lafage, Renaud; Kim, Han Jo; Daniels, Alan H; Gum, Jeffrey L; Diebo, Bassel G; Gupta, Munish C; Soroceanu, Alexandra; Scheer, Justin K; Hamilton, D Kojo; Klineberg, Eric O; Line, Breton; Schoenfeld, Andrew J; Hart, Robert A; Burton, Douglas C; Eastlack, Robert K; Mundis, Gregory M; Mummaneni, Praveen; Chou, Dean; Park, Paul; Schwab, Frank J; Shaffrey, Christopher I; Bess, Shay; Ames, Christopher P; Smith, Justin S; International Spine Study GroupSummary of background data
The influence of frailty on economic burden following corrective surgery for the adult cervical deformity (CD) is understudied and may provide valuable insights for preoperative planning.Objective
To assess the influence of baseline frailty status on the economic burden of CD surgery.Study design
Retrospective cohort.Materials and methods
CD patients with frailty scores and baseline and two-year Neck Disability Index data were included. Frailty score was categorized patients by modified CD frailty index into not frail (NF) and frail (F). Analysis of covariance was used to estimate marginal means adjusting for age, sex, surgical approach, and baseline sacral slope, T1 slope minus cervical lordosis, C2-C7 angle, C2-C7 sagittal vertical axis. Costs were derived from PearlDiver registry data. Reimbursement consisted of a standardized estimate using regression analysis of Medicare payscales for services within a 30-day window including length of stay and death. This data is representative of the national average Medicare cost differentiated by complication/comorbidity outcome, surgical approach, and revision status. Cost per quality-adjusted life-year (QALY) at two years was calculated for NF and F patients.Results
There were 126 patients included. There were 68 NF patients and 58 classified as F. Frailty groups did not differ by overall complications, instance of distal junctional kyphosis, or reoperations (all P >0.05). These groups had similar rates of radiographic and clinical improvement by two years. NF and F had similar overall cost ($36,731.03 vs. $37,356.75, P =0.793), resulting in equivocal costs per QALYs for both patients at two years ($90,113.79 vs. $80,866.66, P =0.097).Conclusion
F and NF patients experienced similar complication rates and upfront costs, with equivocal utility gained, leading to comparative cost-effectiveness with NF patients based on cost per QALYs at two years. Surgical correction for CD is an economical healthcare investment for F patients when accounting for anticipated utility gained and cost-effectiveness following the procedure.Level of evidence
III.Item Open Access The Benefit of Addressing Malalignment In Revision Surgery for Proximal Junctional Kyphosis Following ASD Surgery.(Spine, 2022-09) Passias, Peter G; Krol, Oscar; Williamson, Tyler K; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Line, Breton; Vira, Shaleen; Lipa, Shaina; Daniels, Alan; Diebo, Bassel; Schoenfeld, Andrew; Gum, Jeffrey; Kebaish, Khaled; Park, Paul; Mundis, Gregory; Hostin, Richard; Gupta, Munish C; Eastlack, Robert; Anand, Neel; Ames, Christopher; Hart, Robert; Burton, Douglas; Schwab, Frank J; Shaffrey, Christopher; Klineberg, Eric; Bess, Shay; International Spine Study GroupStudy design
Retrospective cohort study.Objective
Understand the benefit of addressing malalignment in revision surgery for PJK.Summary of background data
Proximal junctional kyphosis(PJK) is a common cause of revision surgery for ASD patients. During a revision, surgeons may elect to perform a proximal extension of the fusion, or also correct the source of the lumbo-pelvic mismatch.Methods
Recurrent PJK following revision surgery was the primary outcome. Revision surgical strategy was the primary predictor(proximal extension of fusion alone compared to combined sagittal correction and proximal extension). Multivariable logistic regression determined rates of recurrent PJK between the two surgical groups with lumbo-pelvic surgical correction assessed through improving ideal alignment in one or more alignment criteria(Global Alignment and Proportionality[GAP],Roussouly-type, and Sagittal Age-Adjusted Score[SAAS]).Results
151 patients underwent revision surgery for PJK. PJK occurred at a rate of 43.0%, and PJF at 12.6%. Patients proportioned in GAP post-revision had lower rates of recurrent PJK(23% vs. 42%;OR: 0.3,95% CI:[0.1-0.8];P=0.024). Following adjusted analysis, patients who were ideally aligned in 1 of 3 criteria (Matching in SAAS and/or Roussouly matched and/or achieved GAP proportionality) had lower rates of recurrent PJK (36% vs. 53%;OR: 0.4,95% CI:[0.1-0.9];P=0.035) and recurrent PJF(OR: 0.1,95% CI:[0.02-0.7];P=0.015). Patients ideally aligned in 2 of 3 criteria avoid any development of PJF(0% vs. 16%, P<0.001).Conclusion
Following revision surgery for proximal junctional kyphosis, patients with persistent poor sagittal alignment showed increased rates of recurrent proximal junctional kyphosis compared with patients who had abnormal lumbo-pelvic alignment corrected during the revision. These findings suggest addressing the root cause of surgical failure in addition to proximal extension of the fusion may be beneficial.Item Open Access The Conceptualization and Derivation of the Cervical Lordosis Distribution Index.(Spine, 2024-09) Passias, Peter G; Williamson, Tyler K; Dave, Pooja; Smith, Justin S; Krol, Oscar; Lafage, Renaud; Line, Breton; Diebo, Bassel G; Daniels, Alan H; Klineberg, Eric O; Eastlack, Robert K; Bess, Shay; Schwab, Frank J; Shaffrey, Christopher I; Lafage, Virginie; Ames, Christopher P; International Spine Study GroupSummary of background data
Yilgor et al developed the lumbar Lordosis Distribution Index to individualize the pelvic mismatch to each patient's pelvic incidence. The cervical lordosis distribution in relation to its apex has not been characterized.Objective
Tailor correction of cervical deformity by incorporating the cervical apex into a distribution index(CLDI) to maximize clinical outcomes while lowering rates of junctional failure.Study design/setting
Retrospective cohort.Methods
CD patients with complete 2Y data were included. Optimal outcome is defined by no DJF, and meeting Virk et al Good Clinical Outcome Criteria:[Meeting 2 of 3: 1)an NDI<20 or meeting MCID, 2)mJOA>=14, 3)an NRS-Neck<=5 or improved by 2 or more points]. C2-T2 lordosis was divided into cranial (C2 to apex) and caudal (apex to T2) arches postoperatively. A cervical lordosis distribution index(CLDI) was developed by dividing the cranial lordotic arch(C2 to apex) by the total segment(C2-T2) and multiplying by 100. Cross-tabulations developed categories for CLDI producing the highest chi-square values for achieving Optimal Outcome at two years and outcomes were assessed by multivariable analysis controlling for significant confounders.Results
84 CD patients were included. Cervical apex distribution postoperatively was: 1% C3, 42% C4, 30% C5, 27% C6. Mean cervical LDI was 117±138. Mean cranial lordosis was 23.2±12.5°. Using cross-tabulations, a CLDI between 70 and 90 was defined as 'Aligned'. Chi-square test revealed significant differences among CLDI categories for DJK, DJF, Good Clinical Outcome, and Optimal Outcome(all P<0.05). Patients aligned in CLDI were less likely to develop DJK(OR: 0.1, [0.01-0.88]), more like to achieve GCO (OR: 3.9, [1.2-13.2]) and Optimal Outcome (OR: 7.9, [2.1-29.3] at two years. Patients aligned in CLDI developed DJF at a rate of 0%.Conclusion
The cervical lordosis distribution index, classified through the cranial segment, takes each unique cervical apex into account and tailors correction to the patient in order to better achieve good clinical outcomes and minimize catastrophic complications following cervical deformity surgery.Level of evidence
III.