Browsing by Author "Krol, Oscar"
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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 An Economic Analysis of Early and Late Complications After Adult Spinal Deformity Correction.(Global spine journal, 2024-04) Williamson, Tyler K; Owusu-Sarpong, Stephane; Imbo, Bailey; Krol, Oscar; Tretiakov, Peter; Joujon-Roche, Rachel; Ahmad, Salman; Bennett-Caso, Claudia; Schoenfeld, Andrew J; Lebovic, Jordan; Vira, Shaleen; Diebo, Bassel; Lafage, Renaud; Lafage, Virginie; Passias, Peter GStudy design/setting
Retrospective cohort.Objective
Adult spinal deformity (ASD) corrective surgery is often a highly invasive procedure portending patients to both immediate and long-term complications. Therefore, we sought to compare the economic impact of certain complications before and after 2 years.Methods
ASD patients with minimum 3-year data included. Complication groups were defined as follows: any complication, major, medical, mechanical, radiographic, and reoperation. Complications stratified by occurrence before or after 2 years postoperatively. Published methods converted ODI to SF-6D to QALYs. Cost was calculated using CMS.gov definitions. Marginalized means for utility gained and cost-per-QALY were calculated via ANCOVA controlling for significant confounders.Results
244 patients included. Before 2Y, complication rates: 76% ≥1 complication, 18% major, 26% required reoperation. After 2Y, complication rates: 32% ≥1 complication, 4% major, 2.5% required reoperation. Major complications after 2 years had worse cost-utility (.320 vs .441, P = .1). Patients suffering mechanical complications accrued the highest overall cost ($130,482.22), followed by infection and PJF for complications before 2 years. Patients suffering a mechanical complication after 2 years had lower cost-utility ($109,197.71 vs $130,482.22, P = .041). Patients developing PJF after 2 years accrued a better cost-utility ($77,227.84 vs $96,873.57; P = .038), compared to PJF before 2 years.Conclusion
Mechanical complications had the single greatest impact on cost-utility after adult spinal deformity surgery, but less so after 2 years. Understanding the cost-utility of specific interventions at certain timepoints may mitigate economic burden and prophylactic efforts should strategically be made against early mechanical complications.Item Open Access Assessing the effects of prehabilitation protocols on post-operative outcomes in adult cervical deformity surgery: does early optimization lead to optimal clinical outcomes?(Spine deformity, 2024-07) Jankowski, Pawel P; Tretiakov, Peter S; Onafowokan, Oluwatobi O; Das, Ankita; Imbo, Bailey; Krol, Oscar; Joujon-Roche, Rachel; Williamson, Tyler; Dave, Pooja; Mir, Jamshaid; Owusu-Sarpong, Stephane; Passias, Peter GPurpose
To investigate the effect of a prehabilitation program on peri- and post-operative outcomes in adult cervical deformity (CD) surgery.Methods
Operative CD patients ≥ 18 years with complete baseline (BL) and 2-year (2Y) data were stratified by enrollment in a prehabilitation program beginning in 2019. Patients were stratified as having undergone prehabilitation (Prehab+) or not (Prehab-). Differences in pre and post-op factors were assessed via means comparison analysis. Costs were calculated using PearlDiver database estimates from Medicare pay-scales.Results
115 patients were included (age: 61 years, 70% female, BMI: 28 kg/m2). Of these patients, 57 (49%) were classified as Prehab+. At baseline, groups were comparable in age, gender, BMI, CCI, and frailty. Surgically, Prehab+ were able to undergo longer procedures (p = 0.017) with equivalent EBL (p = 0.627), and shorter SICU stay (p < 0.001). Post-operatively, Prehab+ patients reported greater reduction in pain scores and greater improvement in quality of life metrics at both 1Y and 2Y than Prehab- patients (all p < 0.05). Prehab+ patients reported significantly less complications overall, as well as less need for reoperation (all p < 0.05).Conclusion
Introducing prehabilitation protocols in adult cervical deformity surgery may aid in improving patient physiological status, enabling patients to undergo longer surgeries with lessened risk of peri- and post-operative complications.Item Open Access Comparing and Contrasting the Clinical Utility of Sagittal Spine Alignment Classification Frameworks: Roussouly Versus SRS-Schwab.(Spine, 2022-03) Passias, Peter G; Bortz, Cole; Pierce, Katherine E; Passfall, Lara; Kummer, Nicholas A; Krol, Oscar; Lafage, Renaud; Diebo, Bassel G; Lafage, Virginie; Ames, Christopher P; Burton, Douglas C; Gupta, Munish C; Sciubba, Daniel M; Schoenfeld, Andrew J; Bess, Shay; Hostin, Richard; Shaffrey, Christopher I; Line, Breton G; Klineberg, Eric O; Smith, Justin S; Schwab, Frank J; International Spine Study GroupStudy design
Retrospective cohort study of a prospectively collected database.Objective
To compare clinical utility of two common classification systems for adult spinal deformity (ASD) and determine whether both should be considered in surgical planning to improve patient outcomes.Summary of background data
Surgical restoration of appropriate Roussouly classification shape or SRS-Schwab ASD classification may improve outcomes.Methods
ASD patients with pre- and 2-year postop (2Y) radiographic/health-related quality of life (HRQL) data were grouped by "theoretical" and "current" Roussouly type. Univariate analyses assessed outcomes of patients who mismatched Roussouly types at both pre- and 2Y intervals (Mismatched) and those of preoperative mismatched patients who matched at 2-years (Matched). Subanalysis assessed outcomes of patients who improved in Schwab modifiers, and patients who both improved in both Schwab modifiers and matched Roussouly type by 2Y.Results
Included: 515 ASD patients (59 ± 14 yrs, 80% F). Preoperative breakdown of "current" Roussouly types: Type 1 (10%), 2 (54%), 3 (24%), and 4 (12%). Matched and Mismatched groups did not differ in rates of reaching MCID for any HRQL metrics by 2Y (all P > 0.10). Reoperation, PJK, and complications did not differ between Matched and Mismatched (all P > 0.10), but Roussouly Matched patients had toward lower rates of instrumentation failure (17.2% vs. 24.8%, P = 0.038). By 2Y, 28% of patients improved in PT Schwab modifier, 37% in SVA, and 46% in PI-LL. Patients who both Matched Roussouly at 2Y and improved in all Schwab modifiers met MCID for Oswestry Disability Index (ODI) and Scoliosis Research Society (SRS) activity at higher rates than patients who did not.Conclusion
Isolated restoration per the Roussouly system was not associated with superior outcomes. Patients who both matched Roussouly type and improved in Schwab modifiers had superior patient-reported outcomes at 2-years. Concurrent consideration of both systems may offer utility in establishing optimal realignment goals.Level of Evidence: 3.Item Open Access Costs of Surgery in Adult Spinal Deformity: Do Higher Cost Surgeries Lead to Better Outcomes?(Spine, 2024-02) Joujon-Roche, Rachel; Dave, Pooja; Tretiakov, Peter; Mcfarland, Kimberly; Mir, Jamshaid; Williamson, Tyler K; Imbo, Bailey; Krol, Oscar; Lebovic, Jordan; Schoenfeld, Andrew J; Vira, Shaleen; Lafage, Renaud; Lafage, Virginie; Passias, Peter GStudy design
This was a retrospective study.Objective
To assess the impact of surgical costs on patient-reported outcomes in adult spinal deformity (ASD).Summary of background data
With increased focus on delivering cost-effective health care, interventions with high-resource utilization, such as ASD surgery, have received greater scrutiny.Materials and methods
ASD patients aged 18 years and older with BL and 2-year data were included. Surgical costs were calculated using the 2021 average Medicare reimbursement by Current Procedural Terminology code. Costs of complications and reoperations were intentionally excluded. Patients were ranked into tertiles by surgical cost: highest surgical costs (HC) and lowest surgical costs (LC). They were propensity score matched to account for differences in baseline age and deformity. Bivariate logistic regressions assessed odds of achieving outcomes.Results
Four hundred twenty-one patients met inclusion (60.7 yr, 81.8% female, Charlson Comorbidity Index: 1.6, 27.1 kg/m 2 ), 139 LC and 127 HC patients. After propensity score matching, 102 patients remained in each cost group with an average reimbursement of LC: $12,494 versus HC: $29,248. Matched cohorts had similar demographics and baseline health-related quality of life. Matched groups had similar baseline sagittal vertical axis (HC: 59.0 vs. LC: 56.7 mm), pelvic incidence and lumbar lordosis (HC: 13.1 vs. LC: 13.4°), and pelvic tilt (HC: 25.3 vs. LC: 22.4°). Rates of complications were not significantly different between the cost groups. Compared with the LC group, by 2 years, HC patients had higher odds of reaching substantial clinical benefit in Oswestry Disability Index [odds ratio (OR): 2.356 (1.220, 4.551), P =0.011], in Scoliosis Research Society-Total [OR: 2.988 (1.515, 5.895), P =0.002], and in Numerical Rating Scale Back [OR: 2.739 (1.105, 6.788), P =0.030]. Similar findings were appreciated for HC patients in the setting of Schwab deformity outcome criteria.Conclusions
Although added cost did not guarantee an ideal outcome, HC patients experienced superior patient-reported outcomes compared with LC patients. Although cost efficiency remains an important priority for health policy, isolating cost reduction may compromise outcomes and add to future costs of reintervention, particularly with more severe baseline deformity.Level of evidence
3.Item Open Access Despite a Multifactorial Etiology, Rates of Distal Junctional Kyphosis After Adult Cervical Deformity Corrective Surgery Can be Dramatically Diminished by Optimizing Age Specific Radiographic Improvement.(Global spine journal, 2024-11) Mir, Jamshaid M; Onafowokan, Oluwatobi O; Jankowski, Pawel P; Krol, Oscar; Williamson, Tyler; Das, Ankita; Thomas, Zach; Padon, Benjamin; Schoenfeld, Andrew J; Janjua, Muhammad Burhan; Passias, Peter GStudy design
Retrospective cohort study of a prospectively collected single-center database.Objective
Distal Junctional Kyphosis (DJK) is one of the most common complications in adult cervical deformity (ACD) correction. The utility of radiographic alignment alone in predicting and minimizing DJK occurrence warrants further study. To investigate the impact of post-operative radiographic alignment on development of DJK in ACD patients.Methods
ACD patients (≥18 yrs) with complete baseline (BL) and two-year (2Y) radiographic data were included. DJF was defined as DJK greater than 15° (Passias et al) or DJK with reop. Multivariable logistic regression (MVA) identified 3-month predictors of DJK. Conditional inference tree (CIT) machine learning analysis determined threshold cutoffs. Radiographic predictors were combined in a model to determine predictive value using area under the curve (AUC) methodology. "Match" refers to ideal age-adjusted alignment.Results
140 cervical deformity patients met inclusion criteria (61.3 yrs, 67% F, BMI: 29 kg/m2, CCI: 0.96 ± 1.3). Surgically, 51.3% had osteotomies, 47.1% had a posterior approach, 34.5% combined approach, 18.5% anterior approach, with an average 7.6 ± 3.8 levels fused and EBL of 824 mL. Overall, 33 patients (23.6%) developed DJK, and 11 patients (9%) developed DJF. MVA controlling for age, and baseline deformity, followed by CIT found 3M cSVA <3.7 cm (OR: .2, 95% CI:.06-.6), and TK T4-T12 <50 (OR:.17, 95% CI:.05-.5, both P < .05) were significant predictors of a lower likelihood of DJK. Receiver operator curve AUC using age, T1S match, TS-CL match, LL-TK match, cSVA <3.7 cm, and T4-T12 <50 predicted DJK with an AUC of .91 for DJK by 2Y, and .88 for DJF by 2Y.Conclusion
These findings suggest post-operative radiographic alignment is strongly associated with distal junctional kyphosis. When utilizing age-adjusted realignment in addition to newly developed thresholds, a suggested post-operative cSVA target of 3.7 cm and thoracic kyphosis less than 50, it is possible to substantially reduce the occurrence of distal junctional kyphosis and distal junctional failure.Item Open Access Development of a modified frailty index for adult spinal deformities independent of functional changes following surgical correction: a true baseline risk assessment tool.(Spine deformity, 2024-02) Passias, Peter G; Pierce, Katherine E; Mir, Jamshaid M; Krol, Oscar; Lafage, Renaud; Lafage, Virginie; Line, Breton; Uribe, Juan S; Hostin, Richard; Daniels, Alan; Hart, Robert; Burton, Douglas; Shaffrey, Christopher; Schwab, Frank; Diebo, Bassel G; Ames, Christopher P; Smith, Justin S; Schoenfeld, Andrew J; Bess, Shay; Klineberg, Eric O; International Spine Study GroupPurpose
To develop a simplified, modified frailty index for adult spinal deformity (ASD) patients dependent on objective clinical factors.Methods
ASD patients with baseline (BL) and 2-year (2Y) follow-up were included. Factors with the largest R2 value derived from multivariate forward stepwise regression were including in the modified ASD-FI (clin-ASD-FI). Factors included in the clin-ASD-FI were regressed against mortality, extended length of hospital stay (LOS, > 8 days), revisions, major complications and weights for the clin-ASD-FI were calculated via Beta/Sullivan. Total clin-ASD-FI score was created with a score from 0 to 1. Linear regression correlated clin-ASD-FI with ASD-FI scores and published cutoffs for the ASD-FI were used to create the new frailty cutoffs: not frail (NF: < 0.11), frail (F: 0.11-0.21) and severely frail (SF: > 0.21). Binary logistic regression assessed odds of complication or reop for frail patients.Results
Five hundred thirty-one ASD patients (59.5 yrs, 79.5% F) were included. The final model had a R2 of 0.681, and significant factors were: < 18.5 or > 30 BMI (weight: 0.0625 out of 1), cardiac disease (0.125), disability employment status (0.3125), diabetes mellitus (0.0625), hypertension (0.0625), osteoporosis (0.125), blood clot (0.1875), and bowel incontinence (0.0625). These factors calculated the score from 0 to 1, with a mean cohort score of 0.13 ± 0.14. Breakdown by clin-ASD-FI score: 51.8% NF, 28.1% F, 20.2% SF. Increasing frailty severity was associated with longer LOS (NF: 7.0, F: 8.3, SF: 9.2 days; P < 0.001). Frailty independently predicted occurrence of any complication (OR: 9.357 [2.20-39.76], P = 0.002) and reop (OR: 2.79 [0.662-11.72], P = 0.162).Conclusions
Utilizing an existing ASD frailty index, we proposed a modified version eliminating the patient-reported components. This index is a true assessment of physiologic status, and represents a superior risk factor assessment compared to other tools for both primary and revision spinal deformity surgery as a result of its immutability with surgery, lack of subjectivity, and ease of use.Item Open Access Dosing Strategy for Osteobiologics Used in ACDF Surgery: Influence on Fusion Rates and Associated Complications. A Systematic Literature Review.(Global spine journal, 2024-02) Hamouda, Waeel O; Veranis, Sotiris; Krol, Oscar; Sagoo, Navraj S; Passias, Peter G; Buser, Zorica; Meisel, Hans Jörg; Yoon, Tim; AO Spine Knowledge Forum DegenerativeStudy design
Systematic review.Objective
To assess the available evidence related to dose-dependent effectiveness (i.e., bone fusion) and morbidity of osteobiologics used in anterior cervical discectomy and fusion (ACDF).Methods
Studies with more than 9 adult patients with degenerated/herniated cervical discs operated for one-to four-levels ACDF reporting used osteobiologics doses, fusion rates at six months or later, and related comorbidities were included. PubMed, EMBASE, ClinicalTrials, and Cochrane were searched through September 2021. Data extracted in spread sheet and risk of bias assessed using MINORS and Rob-2.Results
Sixteen studies were selected and sub-grouped into BMP and non-BMP osteobiologics. For the 10 BMP studies, doses varied from 0.26 to 2.1 mg in 649 patients with fusion rates of 95.3 to 100% at 12 months. For other osteobiologics, each of six studies reported one type of osteobiologic in certain dose/concentration/volume in a total of 580 patients with fusion rates of 6.8 to 96.9% at 12 months. Risk of bias was low in three of the 13 non-randomized (18.75%) and in all the three randomized studies (100%).Conclusions
Taking into account the inconsistent reporting within available literature, for BMP usage in ACDF, doses lower than 0.7 mg per level can achieve equal successful fusion rates as higher doses, and there is no complication-free dose proved yet. It seems that the lower the dose the lower the incidence of serious complications. As for non-BMP osteobiologics the studies are very limited for each osteobiologic and thus conclusions must be drawn individually and with caution.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 Adult Spinal Deformity Corrective Surgery: Does Frailty Severity Exert a Ceiling Effect?(Spine, 2024-09) Passias, Peter G; Onafowokan, Oluwatobi O; Tretiakov, Peter; Williamson, Tyler; Kummer, Nicholas; Mir, Jamshaid; Das, Ankita; Krol, Oscar; Passfall, Lara; Joujon-Roche, Rachel; Imbo, Bailey; Yee, Timothy; Sciubba, Daniel; Paulino, Carl B; Schoenfeld, Andrew J; Smith, Justin S; Lafage, Renaud; Lafage, VirginieStudy design
Retrospective single-center study.Objective
To assess the influence of frailty on optimal outcome following ASD corrective surgery.Summary of background data
Frailty is a determining factor in outcomes after ASD surgery and may exert a ceiling effect on the best possible outcome.Methods
ASD patients with frailty measures, baseline, and 2-year ODI included. Frailty was classified as Not Frail (NF), Frail (F) and Severely Frail (SF) based on the modified Frailty Index, then stratified into quartiles based on two-year ODI improvement (most improved designated "Highest"). Logistic regression analyzed relationships between frailty and ODI score and improvement, maintenance, or deterioration. A Kaplan-Meier survival curve was used to analyze differences in time to complication or reoperation.Results
A total of 393 ASD patients were isolated (55.2% NF, 31.0% F, and 13.7% SF), then classified as 12.5% NF-Highest, 17.8% F-Highest, and 3.1% SF-Highest. The SF group had the highest rate of deterioration (16.7%, P =0.025) in the second postoperative year, but the groups were similar in improvement (NF: 10.1%, F: 11.5%, SF: 9.3%, P =0.886). Improvement of SF patients was greatest at six months (ΔODI of -22.6±18.0, P <0.001), but NF and F patients reached maximal ODI at 2 years (ΔODI of -15.7±17.9 and -20.5±18.4, respectively). SF patients initially showed the greatest improvement in ODI (NF: -4.8±19.0, F: -12.4±19.3, SF: -22.6±18.0 at six months, P <0.001). A Kaplan-Meier survival curve showed a trend of less time to major complication or reoperation by 2 years with increasing frailty (NF: 7.5±0.381 yr, F: 6.7±0.511 yr, SF: 5.8±0.757 yr; P =0.113).Conclusions
Increasing frailty had a negative effect on maximal improvement, where severely frail patients exhibited a parabolic effect with greater initial improvement due to higher baseline disability, but reached a ceiling effect with less overall maximal improvement. Severe frailty may exert a ceiling effect on improvement and impair maintenance of improvement following surgery.Level of evidence
Level III.Item Open Access Identifying Subsets of Patients With Adult Spinal Deformity Who Maintained a Positive Response to Nonoperative Management.(Neurosurgery, 2023-03) Passias, Peter G; Ahmad, Waleed; Tretiakov, Peter; Krol, Oscar; Segreto, Frank; Lafage, Renaud; Lafage, Virginie; Soroceanu, Alex; Daniels, Alan; Gum, Jeffrey; Line, Breton; Schoenfeld, Andrew J; Vira, Shaleen; Hart, Robert; Burton, Douglas; Smith, Justin S; Ames, Christopher P; Shaffrey, Christopher; Schwab, Frank; Bess, Shay; International Spine Study GroupBackground
Adult spinal deformity (ASD) represents a major cause of disability in the elderly population in the United States. Surgical intervention has been shown to reduce disability and pain in properly indicated patients. However, there is a small subset of patients in whom nonoperative treatment is also able to durably maintain or improve symptoms.Objective
To examine the factors associated with successful nonoperative management in patients with ASD.Methods
We retrospectively evaluated a cohort of 207 patients with nonoperative ASD, stratified into 3 groups: (1) success, (2) no change, and (3) failure. Success was defined as a gain in minimal clinically importance difference in both Oswestry Disability Index and Scoliosis Research Society-Pain. Logistic regression model and conditional inference decision trees established cutoffs for success according to baseline (BL) frailty and sagittal vertical axis.Results
In our cohort, 44.9% of patients experienced successful nonoperative treatment, 22.7% exhibited no change, and 32.4% failed. Successful nonoperative patients at BL were significantly younger, had a lower body mass index, decreased Charlson Comorbidity Index, lower frailty scores, lower rates of hypertension, obesity, depression, and neurological dysfunction (all P < .05) and significantly higher rates of grade 0 deformity for all Schwab modifiers (all P < .05). Conditional inference decision tree analysis determined that patients with a BL ASD-frailty index ≤ 1.579 (odds ratio: 8.3 [4.0-17.5], P < .001) were significantly more likely to achieve nonoperative success.Conclusion
Success of nonoperative treatment was more frequent among younger patients and those with less severe deformity and frailty at BL, with BL frailty the most important determinant factor. The factors presented here may be useful in informing preoperative discussion and clinical decision-making regarding treatment strategies.Item Open Access Impact of Frailty on the Development of Proximal Junctional Failure: Does Frailty Supersede Achieving Optimal Realignment?(Spine, 2023-10) Krol, Oscar; McFarland, Kimberly; Owusu-Sarpong, Stephane; Sagoo, Navraj; Williamson, Tyler; Joujon-Roche, Rachel; Tretiakov, Peter; Imbo, Bailey; Dave, Pooja; Mir, Jamshaid; Lebovic, Jordan; Onafowokan, Oluwatobi O; Schoenfeld, Andrew J; De la Garza Ramos, Rafael; Janjua, Muhammad Burhan; Sciubba, Daniel M; Diebo, Bassel G; Vira, Shaleen; Smith, Justin S; Lafage, Virginie; Lafage, Renaud; Passias, Peter GBackground
Patients undergoing surgery for adult spinal deformity (ASD) are often elderly, frail, and at elevated risk of adverse events perioperatively, with proximal junctional failure (PJF) occurring relatively frequently. Currently, the specific role of frailty in potentiating this outcome is poorly defined.Purpose
To determine if the benefits of optimal realignment in ASD, with respect to the development of PJF, can be offset by increasing frailty.Study design
Retrospective cohort.Materials and methods
Operative ASD patients (scoliosis >20°, SVA>5 cm, pelvic tilt>25°, or TK>60°) fused to the pelvis or below with available baseline and 2-year (2Y) radiographic and HRQL data were included. The Miller Frailty Index (FI) was used to stratify patients into 2 categories: Not Frail (FI <3) and Frail (>3). Proximal Junctional Failure (PJF) was defined using the Lafage criteria. "Matched" and "unmatched" refers to ideal age-adjusted alignment postoperatively. Multivariable regression determined the impact of frailty on the development of PJF.Results
Two hundred eighty-four ASD patients met inclusion criteria [62.2yrs±9.9, 81%F, BMI: 27.5 kg/m 2 ±5.3, ASD-FI: 3.4±1.5, Charlson Comorbidity Index (CCI): 1.7±1.6]. Forty-three percent of patients were characterized as Not Frail (NF) and 57% were characterized as Frail (F). PJF development was lower in the NF group compared with the F group (7% vs . 18%; P =0.002). F patients had 3.2 × higher risk of PJF development compared to NF patients (OR: 3.2, 95% CI: 1.3-7.3, P =0.009). Controlling for baseline factors, F unmatched patients had a higher degree of PJF (OR: 1.4, 95% CI:1.02-1.8, P =0.03); however, with prophylaxis, there was no increased risk. Adjusted analysis shows F patients, when matched postoperatively in PI-LL, had no significantly higher risk of PJF.Conclusions
An increasingly frail state is significantly associated with the development of PJF after corrective surgery for ASD. Optimal realignment may mitigate the impact of frailty on eventual PJF. Prophylaxis should be considered in frail patients who do not reach ideal alignment goals.Item Open Access Long-term Morbidity in Patients After Surgical Correction of Adult Spinal Deformity: Results From a Cohort With Minimum 5-year Follow-up.(Spine, 2023-08) Imbo, Bailey; Williamson, Tyler; Joujon-Roche, Rachel; Krol, Oscar; Tretiakov, Peter; Ahmad, Salman; Bennett-Caso, Claudia; Schoenfeld, Andrew J; Dinizo, Michael; De La Garza-Ramos, Rafael; Janjua, M Burhan; Vira, Shaleen; Ihejirika-Lomedico, Rivka; Raman, Tina; O'Connell, Brooke; Maglaras, Constance; Paulino, Carl; Diebo, Bassel; Lafage, Renaud; Lafage, Virginie; Passias, Peter GStudy design
Retrospective.Objective
The objective of this study is to describe the rate of postoperative morbidity before and after two-year (2Y) follow-up for patients undergoing surgical correction of adult spinal deformity (ASD).Summary of background data
Advances in modern surgical techniques for deformity surgery have shown promising short-term clinical results. However, the permanence of radiographic correction, mechanical complications, and revision surgery in ASD surgery remains a clinical challenge. Little information exists on the incidence of long-term morbidity beyond the acute postoperative window.Methods
ASD patients with complete baseline and five-year (5Y) health-related quality of life and radiographic data were included. The rates of adverse events, including proximal junctional kyphosis (PJK), proximal junctional failure (PJF), and reoperations up to 5Y were documented. Primary and revision surgeries were compared. We used logistic regression analysis to adjust for demographic and surgical confounders.Results
Of 118 patients eligible for 5Y follow-up, 99(83.9%) had complete follow-up data. The majority were female (83%), mean age 54.1 years and 10.4 levels fused and 14 undergoing three-column osteotomy. Thirty-three patients had a prior fusion and 66 were primary cases. By 5Y postop, the cohort had an adverse event rate of 70.7% with 25 (25.3%) sustaining a major complication and 26 (26.3%) receiving reoperation. Thirty-eight (38.4%) developed PJK by 5Y and 3 (4.0%) developed PJF. The cohort had a significantly higher rate of complications (63.6% vs. 19.2%), PJK (34.3% vs. 4.0%), and reoperations (21.2% vs. 5.1%) before 2Y, all P <0.01. The most common complications beyond 2Y were mechanical complications.Conclusions
Although the incidence of adverse events was high before 2Y, there was a substantial reduction in longer follow-up indicating complications after 2Y are less common. Complications beyond 2Y consisted mostly of mechanical issues.Item Open Access Natural history of adult spinal deformity: how do patients with suboptimal surgical outcomes fare relative to nonoperative counterparts?(Journal of neurosurgery. Spine, 2023-07) Passias, Peter G; Joujon-Roche, Rachel; Mir, Jamshaid M; Williamson, Tyler K; Tretiakov, Peter S; Imbo, Bailey; Krol, Oscar; Passfall, Lara; Ahmad, Salman; Lebovic, Jordan; Owusu-Sarpong, Stephane; Lanre-Amos, Tomi; Protopsaltis, Themistocles; Lafage, Renaud; Lafage, Virginie; Park, Paul; Chou, Dean; Mummaneni, Praveen V; Fu, Kai-Ming G; Than, Khoi D; Smith, Justin S; Janjua, M Burhan; Schoenfeld, Andrew J; Diebo, Bassel G; Vira, ShaleenObjective
Management of adult spinal deformity (ASD) has increasingly favored operative intervention; however, the incidence of complications and reoperations is high, and patients may fail to achieve idealized postsurgical results. This study compared health-related quality of life (HRQOL) metrics between patients with suboptimal surgical outcomes and those who underwent nonoperative management as a proxy for the natural history (NH) of ASD.Methods
ASD patients with 2-year data were included. Patients who were offered surgery but declined were considered nonoperative (i.e., NH) patients. Operative patients with suboptimal outcome (SOp)-defined as any reoperation, major complication, or ≥ 2 severe Scoliosis Research Society (SRS)-Schwab modifiers at follow-up-were selected for comparison. Propensity score matching (PSM) on the basis of baseline age, deformity, SRS-22 Total, and Charlson Comorbidity Index score was used to match the groups. ANCOVA and stepwise logistic regression analysis were used to assess outcomes between groups at 2 years.Results
In total, 441 patients were included (267 SOp and 174 NH patients). After PSM, 142 patients remained (71 SOp 71 and 71 NH patients). At baseline, the SOp and NH groups had similar demographic characteristics, HRQOL, and deformity (all p > 0.05). At 2 years, ANCOVA determined that NH patients had worse deformity as measured with sagittal vertical axis (36.7 mm vs 21.3 mm, p = 0.025), mismatch between pelvic incidence and lumbar lordosis (11.9° vs 2.9°, p < 0.001), and pelvic tilt (PT) (23.1° vs 20.7°, p = 0.019). The adjusted regression analysis found that SOp patients had higher odds of reaching the minimal clinically important differences in Oswestry Disability Index score (OR [95% CI] 4.5 [1.7-11.5], p = 0.002), SRS-22 Activity (OR [95% CI] 3.2 [1.5-6.8], p = 0.002), SRS-22 Pain (OR [95% CI] 2.8 [1.4-5.9], p = 0.005), and SRS-22 Total (OR [95% CI] 11.0 [3.5-34.4], p < 0.001).Conclusions
Operative patients with SOp still experience greater improvements in deformity and HRQOL relative to the progressive radiographic and functional deterioration associated with the NH of ASD. The NH of nonoperative management should be accounted for when weighing the risks and benefits of operative intervention for ASD.Item Open Access Outcomes and survival analysis of adult cervical deformity patients with 10-year follow-up.(The spine journal : official journal of the North American Spine Society, 2024-03) Passias, Peter G; Tretiakov, Peter S; Das, Ankita; Thomas, Zach; Krol, Oscar; Joujon-Roche, Rachel; Williamson, Tyler; Imbo, Bailey; Owusu-Sarpong, Stephane; Lebovic, Jordan; Diebo, Bassel; Vira, Shaleen; Lafage, Virginie; Schoenfeld, Andrew JBackground
Previous studies have demonstrated that adult cervical deformity patients may be at increased risk of death in conjunction with increased frailty or a weakened physiologic state. However, such studies have often been limited by follow-up duration, and longer-term studies are needed to better assess temporal changes in ACD patients and associated mortality risk.Purpose
To assess if patients with decreased comorbidities and physiologic burden will be at lessened risk of death for a greater length of time after undergoing adult cervical deformity surgery.Study design/setting
Retrospective review.Patient sample
Two hundred ninety ACD patients.Outcome measures
Morbidity and mortality data.Methods
Operative ACD patients ≥18 years with pre-(BL) and 10-year (10Y) data were included. Patients were stratified as expired versus living, as well as temporally grouped by Expiration prior to 5Y or between 5Y and 10Y. Group differences were assessed via means comparison analysis. Backstep logistic regression identified mortality predictors. Kaplan-Meier analysis assessed survivorship of expired patients. Log rank analysis determined differences in survival distribution groups.Results
Sixty-six total patients were included (60.97±10.19 years, 48% female, 28.03±7.28 kg/m2). Within 10Y, 12 (18.2% of ACD cohort) expired. At baseline, patients were comparable in age, gender, BMI, and CCI total on average (all p>.05). Furthermore, patients were comparable in BL HRQLs (all p>.05). However, patients who expired between 5Y and 10Y demonstrated higher BL EQ5D and mJOA scores than their earlier expired counterparts at 2Y (p<.021). Furthermore, patients who presented with no CCI markers at BL were significantly more likely to survive until the 5Y-10Y follow-up window. Surgically, the only differences observed between patients who survived until 5Y was in undergoing osteotomy, with longer survival seen in those who did not require it (p=.003). Logistic regression revealed independent predictors of death prior to 5Y to be increased BMI, increased frailty, and increased levels fused (model p<.001). KM analysis found that by Passias et al frailty, not frail patients had mean survival time of 170.56 weeks, versus 158.00 in frail patients (p=.949).Conclusions
Our study demonstrates that long-term survival after cervical deformity surgery may be predicted by baseline surgical factors. By optimizing BMI, frailty status, and minimizing fusion length when appropriate, surgeons may be able to further assist ACD patients in increasing their survivability postoperatively.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 Predictive Analytics for Determining Extended Operative Time in Corrective Adult Spinal Deformity Surgery.(International journal of spine surgery, 2022-04) Passias, Peter G; Poorman, Gregory W; Vasquez-Montes, Dennis; Kummer, Nicholas; Mundis, Gregory; Anand, Neel; Horn, Samantha R; Segreto, Frank A; Passfall, Lara; Krol, Oscar; Diebo, Bassel; Burton, Doug; Buckland, Aaron; Gerling, Michael; Soroceanu, Alex; Eastlack, Robert; Kojo Hamilton, D; Hart, Robert; Schwab, Frank; Lafage, Virginie; Shaffrey, Christopher; Sciubba, Daniel; Bess, Shay; Ames, Christopher; Klineberg, Eric; International Spine Study GroupBackground
More sophisticated surgical techniques for correcting adult spinal deformity (ASD) have increased operative times, adding to physiologic stress on patients and increased complication incidence. This study aims to determine factors associated with operative time using a statistical learning algorithm.Methods
Retrospective review of a prospective multicenter database containing 837 patients undergoing long spinal fusions for ASD. Conditional inference decision trees identified factors associated with skin-to-skin operative time and cutoff points at which factors have a global effect. A conditional variable-importance table was constructed based on a nonreplacement sampling set of 2000 conditional inference trees. Means comparison for the top 15 variables at their respective significant cutoffs indicated effect sizes.Results
Included: 544 surgical ASD patients (mean age: 58.0 years; fusion length 11.3 levels; operative time: 378 minutes). The strongest predictor for operative time was institution/surgeon. Center/surgeons, grouped by decision tree hierarchy, a and b were, on average, 2 hours faster than center/surgeons c-f, who were 43 minutes faster than centers g-j, all P < 0.001. The next most important predictors were, in order, approach (combined vs posterior increases time by 139 minutes, P < 0.001), levels fused (<4 vs 5-9 increased time by 68 minutes, P < 0.050; 5-9 vs < 10 increased time by 47 minutes, P < 0.001), age (age <50 years increases time by 57 minutes, P < 0.001), and patient frailty (score <1.54 increases time by 65 minutes, P < 0.001). Surgical techniques, such as three-column osteotomies (35 minutes), interbody device (45 minutes), and decompression (48 minutes), also increased operative time. Both minor and major complications correlated with <66 minutes of increased operative time. Increased operative time also correlated with increased hospital length of stay (LOS), increased estimated intraoperative blood loss (EBL), and inferior 2-year Oswestry Disability Index (ODI) scores.Conclusions
Procedure location and specific surgeon are the most important factors determining operative time, accounting for operative time increases <2 hours. Surgical approach and number of levels fused were also associated with longer operative times, respectively. Extended operative time correlated with longer LOS, higher EBL, and inferior 2-y ODI outcomes.Clinical relevance
We further identified the poor outcomes associated with extended operative time during surgical correction of ASD, and attributed the useful predictors of time spent in the operating room, including site, surgeon, surgical approach, and the number of levels fused.Level of evidence: 3
Item Open Access Predictors of reoperation for spinal disorders in Chiari malformation patients with prior surgical decompression.(Journal of craniovertebral junction & spine, 2023-10) Onafowokan, Oluwatobi O; Das, Ankita; Mir, Jamshaid M; Alas, Haddy; Williamson, Tyler K; Mcfarland, Kimberly; Varghese, Jeffrey; Naessig, Sara; Imbo, Bailey; Passfall, Lara; Krol, Oscar; Tretiakov, Peter; Joujon-Roche, Rachel; Dave, Pooja; Moattari, Kevin; Owusu-Sarpong, Stephane; Lebovic, Jordan; Vira, Shaleen; Diebo, Bassel; Lafage, Virginie; Passias, Peter GustBackground
Chiari malformation (CM) is a cluster of related developmental anomalies of the posterior fossa ranging from asymptomatic to fatal. Cranial and spinal decompression can help alleviate symptoms of increased cerebrospinal fluid pressure and correct spinal deformity. As surgical intervention for CM increases in frequency, understanding predictors of reoperation may help optimize neurosurgical planning.Materials and methods
This was a retrospective analysis of the prospectively collected Healthcare Cost and Utilization Project's California State Inpatient Database years 2004-2011. Chiari malformation Types 1-4 (queried with ICD-9 CM codes) with associated spinal pathologies undergoing stand-alone spinal decompression (queried with ICD-9 CM procedure codes) were included. Cranial decompressions were excluded.Results
One thousand four hundred and forty-six patients (29.28 years, 55.6% of females) were included. Fifty-eight patients (4.01%) required reoperation (67 reoperations). Patients aged 40-50 years had the most reoperations (11); however, patients aged 15-20 years had a significantly higher reoperation rate than all other groups (15.5% vs. 8.2%, P = 0.048). Female gender was significantly associated with reoperation (67.2% vs. 55.6%, P = 0.006). Medical comorbidities associated with reoperation included chronic lung disease (19% vs. 6.9%, P < 0.001), iron deficiency anemia (10.3% vs. 4.1%, P = 0.024), and renal failure (3.4% vs. 0.9%, P = 0.05). Associated significant cluster anomalies included spina bifida (48.3% vs. 34.8%, P = 0.035), tethered cord syndrome (6.9% vs. 2.1%, P = 0.015), syringomyelia (12.1% vs. 5.9%, P = 0.054), hydrocephalus (37.9% vs. 17.7%, P < 0.001), scoliosis (13.8% vs. 6.4%, P = 0.028), and ventricular septal defect (6.9% vs. 2.3%, P = 0.026).Conclusions
Multiple medical and CM-specific comorbidities were associated with reoperation. Addressing them, where possible, may aid in improving CM surgery outcomes.Item Open Access Prioritization of Realignment Associated With Superior Clinical Outcomes for Cervical Deformity Patients.(Neurospine, 2021-09) Pierce, Katherine E; Passias, Peter G; Brown, Avery E; Bortz, Cole A; Alas, Haddy; Passfall, Lara; Krol, Oscar; Kummer, Nicholas; Lafage, Renaud; Chou, Dean; Burton, Douglas C; Line, Breton; Klineberg, Eric; Hart, Robert; Gum, Jeffrey; Daniels, Alan; Hamilton, Kojo; Bess, Shay; Protopsaltis, Themistocles; Shaffrey, Christopher; Schwab, Frank A; Smith, Justin S; Lafage, Virginie; Ames, Christopher; International Spine Study Group (ISSG)Objective
To prioritize the cervical parameter targets for alignment.Methods
Included: cervical deformity (CD) patients (C2-7 Cobb angle > 10°, cervical lordosis > 10°, cervical sagittal vertical axis [cSVA] > 4 cm, or chin-brow vertical angle > 25°) with full baseline (BL) and 1-year (1Y) radiographic parameters and Neck Disability Index (NDI) scores; patients with cervical [C] or cervicothoracic [CT] Primary Driver Ames type. Patients with BL Ames classified as low CD for both parameters of cSVA ( < 4 cm) and T1 slope minus cervical lordosis (TS-CL) ( < 15°) were excluded. Patients assessed: meeting minimum clinically important differences (MCID) for NDI ( < -15 ΔNDI). Ratios of correction were found for regional parameters categorized by primary Ames driver (C or CT). Decision tree analysis assessed cutoffs for differences associated with meeting NDI MCID at 1Y.Results
Seventy-seven CD patients (mean age, 62.1 years; 64% female; body mass index, 28.8 kg/m2). Forty-one point six percent of patients met MCID for NDI. A backwards linear regression model including radiographic differences as predictors from BL to 1Y for meeting MCID for NDI demonstrated an R2 of 0.820 (p = 0.032) included TS-CL, cSVA, McGregor's slope (MGS), C2 sacral slope, C2-T3 angle, C2-T3 SVA, cervical lordosis. By primary Ames driver, 67.5% of patients were C, and 32.5% CT. Ratios of change in predictors for MCID NDI patients for C and CT were not significant between the 2 groups (p > 0.050). Decision tree analysis determined cutoffs for radiographic change, prioritizing in the following order: ≥ 42.5° C2-T3 angle, > 35.4° cervical lordosis, < -31.76° C2 slope, < -11.57-mm cSVA, < -2.16° MGS, > -30.8-mm C2-T3 SVA, and ≤ -33.6° TS-CL.Conclusion
Certain ratios of correction of cervical parameters contribute to improving neck disability. Prioritizing these radiographic alignment parameters may help optimize patient-reported outcomes for patients undergoing CD surgery.Item Open Access Prioritization of realignment associated with superior clinical outcomes for surgical cervical deformity patients.(Journal of craniovertebral junction & spine, 2021-07) Pierce, Katherine E; Passias, Peter Gust; Brown, Avery E; Bortz, Cole A; Alas, Haddy; Lafage, Renaud; Krol, Oscar; Chou, Dean; Burton, Douglas C; Line, Breton; Klineberg, Eric; Hart, Robert; Gum, Jeffrey; Daniels, Alan; Hamilton, Kojo; Bess, Shay; Protopsaltis, Themistocles; Shaffrey, Christopher; Schwab, Frank A; Smith, Justin S; Lafage, Virginie; Ames, Christopher; International Spine Study GroupBackground
To optimize quality of life in patients with cervical deformity (CD), there may be alignment targets to be prioritized.Objective
To prioritize the cervical parameter targets for alignment.Methods
Included: CD patients (C2-C7 Cobb >10°°, C2-C7 lordosis [CL] >10°°, cSVA > 4 cm, or chin-brow vertical angle >25°°) with full baseline (BL) and 1-year (1Y) radiographic parameters and Neck Disability Index (NDI) scores; patients with cervical (C) or cervicothoracic (CT) Primary Driver Ames type. Patients with BL Ames classified as low CD for both parameters of cSVA (<4 cm) and T1 slope minus CL (TS-CL) (<15°°) were excluded. Patients assessed: Meeting Minimal Clinically Important Difference (MCID) for NDI (<-15 ΔNDI). Ratios of correction were found for regional parameters categorized by Primary Ames Driver (C or CT). Decision tree analysis assessed cut-offs for differences associated with meeting NDI MCID at 1Y.Results
Seventy-seven CD patients (62.1 years, 64%F, 28.8 kg/m2). 41.6% met MCID for NDI. A backward linear regression model including radiographic differences as predictors from BL to 1Y for meeting MCID for NDI demonstrated an R 2= 0.820 (P = 0.032) included TS-CL, cSVA, MGS, C2SS, C2-T3 angle, C2-T3 sagittal vertical axis (SVA), CL. By primary Ames driver, 67.5% of patients were C, and 32.5% CT. Ratios of change in predictors for MCID NDI patients for C and CT were not significant between the two groups (P > 0.050). Decision tree analysis determined cut-offs for radiographic change, prioritizing in the following order: ≥42.5° C2-T3 angle, >35.4° CL, <-31.76° C2 slope, <-11.57 mm cSVA, <-2.16° MGS, >-30.8 mm C2-T3 SVA, and ≤-33.6° TS-CL.Conclusions
Certain ratios of correction of cervical parameters contribute to improving neck disability. Prioritizing these radiographic alignment parameters may help optimize patient-reported outcomes for patients undergoing CD surgery.