Highest Achievable Outcomes for Adult Spinal Deformity Corrective Surgery: Does Frailty Severity Exert a Ceiling Effect?

STUDY 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 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 2-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: 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) at 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 6 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 6 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 years, F: 6.7±0.511 years, SF: 5.8±0.757 years; 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: III.

The Impact of Peri-operative Enhanced Recovery After Surgery Protocols on Outcomes Following Adult Cervical Deformity Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To assess the impact of Enhanced recovery after surgery (ERAS) protocols on peri-operative course in adult cervical deformity (ACD) corrective surgery. METHODS: Patients ≥18 yrs with complete pre-(BL) and up to 2-year (2Y) radiographic and clinical outcome data were stratified by enrollment in an ERAS protocol that commenced in 2020. Differences in demographics, clinical outcomes, radiographic alignment targets, peri-operative factors and complication rates were assessed via means comparison analysis. Logistic regression analysed differences while controlling for baseline disability and deformity. RESULTS: We included 220 patients (average age 58.1 ± 11.9 years, 48% female). 20% were treated using the ERAS protocol (ERAS+). Disability was similar between both groups at baseline. When controlling for baseline disability and myelopathy, ERAS- patients were more likely to utilize opioids than ERAS+ (OR 1.79, 95% CI: 1.45-2.50, P = .016). Peri-operatively, ERAS+ had significantly lower operative time (P < .021), lower EBL (583.48 vs 246.51, P < .001), and required significantly lower doses of propofol intra-operatively than ERAS- patients (P = .020). ERAS+ patients also reported lower mean LOS overall (4.33 vs 5.84, P = .393), and were more likely to be discharged directly to home (χ2(1) = 4.974, P = .028). ERAS+ patients were less likely to require steroids after surgery (P = .045), were less likely to develop neuromuscular complications overall (P = .025), and less likely experience venous complications or be diagnosed with venous disease post-operatively (P = .025). CONCLUSIONS: Enhanced recovery after surgery programs in ACD surgery demonstrate significant benefit in terms of peri-operative outcomes for patients.

Comparison of multilevel low-grade techniques versus three-column osteotomies in adult spinal deformity surgery: does harmonious correction matter?

OBJECTIVE: Recent debate has arisen between whether to use a three-column osteotomy (3CO) or multilevel low-grade (MLG) techniques to treat severe sagittal malalignment in adult spinal deformity (ASD) surgery. The goal of this study was to compare the outcomes of 3CO and MLG techniques performed in corrective surgeries for ASD. METHODS: ASD patients who had a baseline PI-LL > 30° and 2-year follow-up data were included. Patients underwent either 3CO or MLG (thoracolumbar posterior column osteotomies at ≥ 3 levels or anterior lumbar interbody fusion at ≥ 3 levels with no 3CO). The segmental utility ratio was used to assess relative segmental correction (segmental correction divided by overall correction in lordosis divided by the number of thoracolumbar interventions [interbody fusion, thoracolumbar posterior column osteotomies, and 3CO]). The paired t-test was used to assess lordotic distribution by differences in lordosis between adjacent lumbar disc spaces (e.g., L1-2 to L2-3). Multivariate analysis, controlling for age, sex, BMI, osteoporosis, baseline pelvic incidence, and T1 pelvic angle, was used to evaluate the complication rates and radiographic and patient-reported outcomes between the groups. RESULTS: A total of 93 patients were included, 53% of whom underwent MLG and 47% of whom underwent 3CO. The MLG group had a lower BMI (p < 0.05). MLG patients received fewer previous fusions than 3CO patients (31% vs 80%, p < 0.001). MLG patients had 24% less blood loss but a 22% longer operative time (565 vs 419 minutes, p = 0.008). Using adjusted analysis, the 3CO group had greater segmental and relative correction at each level (segmental utility ratio mean 69% for 3CO vs 23% for MLG, p < 0.001). However, the 3CO group had lordotic differences between two adjacent lumbar disc pairs (range -0.5° to 9.0°, p = 0.009), while MLG was more harmonious (range 2.2°-6.5°, p > 0.4). MLG patients were more likely to undergo realignment to age-adjusted standards (OR 5.6, 95% CI 1.2-46.4; p = 0.033). MLG patients were less likely to develop neurological complications or undergo reoperation (OR 0.4, 95% CI 0.1-0.9; p = 0.041). Adjusted analysis revealed that MLG patients more often met a substantial clinical benefit in the Oswestry Disability Index score (OR 5.3, 95% CI 1.1-26.8; p = 0.043). CONCLUSIONS: MLG techniques showed better utility in lumbar distribution and age-adjusted global correction while minimizing neurological complications and reoperation rates by 2 years postoperatively. In selected instances, these techniques may offer the spine deformity surgeon a safer alternative when correcting severe adult spinal deformity.

Assessing the effects of prehabilitation protocols on post-operative outcomes in adult cervical deformity surgery: does early optimization lead to optimal clinical outcomes?

PURPOSE: 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.

Costs of Surgery in Adult Spinal Deformity: Do Higher Cost Surgeries Lead to Better Outcomes?

STUDY 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.

Patient-Centered Outcomes Following Prone Lateral Single-Position Approach to Same-Day Circumferential Spine Surgery.

STUDY DESIGN: Retrospective study. OBJECTIVE: Evaluate surgical characteristics and postoperative 2-year results of the PL approach to spinal fusion. SUMMARY OF BACKGROUND DATA: Prone-lateral(PL) single positioning has recently gained popularity in spine surgery due to lower blood loss and operative time but has yet to be examined for other notable outcomes, including realignment and patient-reported measures. MATERIALS AND METHODS: We included circumferential spine fusion patients with a minimum one-year follow-up. Patients were stratified into groups based on undergoing PL approach versus same-day staged (Staged). Mean comparison tests identified differences in baseline parameters. Multivariable logistic regression, controlling for age, levels fused, and Charlson Comorbidity Index were used to determine the influence of the approach on complication rates, radiographic and patient-reported outcomes up to two years. RESULTS: One hundred twenty-two patients were included of which 72(59%) were same-day staged and 50(41%) were PL. PL patients were older with lower body mass index (both P <0.05). Patients undergoing PL procedures had lower estimated blood loss and operative time (both P <0.001), along with fewer osteotomies (63% vs. 91%, P <0.001). This translated to a shorter length of stay (3.8 d vs. 4.9, P =0.041). PL procedures demonstrated better correction in both PT (4.0 vs. -0.2, P =0.033 and pelvic incidence and lumbar lordosis (-3.7 vs. 3.1, P =0.012). PL procedures were more likely to improve in GAP relative pelvic version (OR: 2.3, [1.5-8.8]; P =0.003]. PL patients suffered lesser complications during the perioperative period and greater improvement in NRS-Back (-6.0 vs. -3.3, P =0.031), with less reoperations (0.0% vs. 4.8%, P =0.040) by two years. CONCLUSIONS: Patients undergoing PL single-position procedures received less invasive procedures with better correction of pelvic compensation, as well as earlier discharge. The prone lateral cohort also demonstrated greater clinical improvement and a lower rate of reoperations by two years following spinal corrective surgery. LEVEL OF EVIDENCE: Level-III.

Can Baseline Disability Predict Outcomes in Adult Spinal Deformity Surgery?

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: To assess if there is a threshold of baseline disability beyond which the patient-reported outcomes after surgical correction of adult spinal deformity (ASD) are adversely impacted. BACKGROUND: Patient-reported outcomes vary after correction of adult spinal deformity, even when patients are optimally realigned. There is a paucity of literature examining the impact of baseline disability on patient-reported outcomes in ASD. METHODS: Patients with baseline (BL) and two-year data were included. Disability was ranked according to BL Oswestry Disability Index (ODI) into quintiles: Q1 (lowest ODI score) to Q5 (highest ODI score). Adjusted logistic regression analyses evaluated the likelihood of reaching ≥1 MCID in Scoliosis Research Society Outcomes Questionnaire (SRS-22) Pain, SRS-22 Activity, and Short Form-36 physical component summary at two years across disability groups Q1-Q4 with respect to Q5. Sensitivity tests were performed, excluding patients with any "0" Schwab modifiers at BL. RESULTS: Compared with patients in Q5, the odds of reaching MCID in SRS-22 Pain at 2Y were significantly higher for those in Q1 (OR: 3.771), Q2 (OR: 3.006), and Q3 (OR: 2.897), all P <0.021. Similarly, compared with patients in Q5, the odds of reaching MCID in SRS-22 Activity at two years were significantly higher for those in Q2 (OR: 3.454) and Q3 (OR: 2.801), both P <0.02. Lastly, compared with patients in Q5, odds of reaching MCID in Short Form-36 physical component summary at two years were significantly higher for patients in Q1 (OR: 5.350), Q2 (OR: 4.795), and Q3 (OR: 6.229), all P <0.004. CONCLUSIONS: This study found that patients presenting with moderate disability at BL (ODI<40) consistently surpassed health-related quality of life outcomes as compared with those presenting with greater levels of disability. We propose that a baseline ODI of 40 represents a disability threshold within which operative inte rvention maximizes patient-reported outcomes. Furthermore, delaying the intervention until patients progress to severe disability may limit the benefits of surgical correction in ASD patients. LEVEL OF EVIDENCE: 3.

Factors Influencing Maintenance of Alignment and Functional Improvement Following Adult Spinal Deformity Surgery: A 3-Year Outcome Analysis.

STUDY DESIGN: This was a retrospective review. OBJECTIVE: To assess the factors contributing to durability of surgical results following adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND: Factors contributing to the long-term sustainability of ASD correction are currently undefined. MATERIALS AND METHODS: Operative ASD patients with preoperatively (baseline) and 3-year postoperatively radiographic/health-related quality of life data were included. At 1 and 3 years postoperatively, a favorable outcome was defined as meeting at least three of four criteria: (1) no proximal junctional failure or mechanical failure with reoperation, (2) best clinical outcome (BCO) for Scoliosis Research Society (SRS) (≥4.5) or Oswestry Disability Index (ODI) (<15), (3) improving in at least one SRS-Schwab modifier, and (4) not worsening in any SRS-Schwab modifier. A robust surgical result was defined as having a favorable outcome at both 1 and 3 years. Predictors of robust outcomes were identified using multivariable regression analysis with conditional inference tree for continuous variables. RESULTS: We included 157 ASD patients in this analysis. At 1 year postoperatively, 62 patients (39.5%) met the BCO definition for ODI and 33 (21.0%) met the BCO for SRS. At 3 years, 58 patients (36.9%) had BCO for ODI and 29 (18.5%) for SRS. Ninety-five patients (60.5%) were identified as having a favorable outcome at 1 year postoperatively. At 3 years, 85 patients (54.1%) had a favorable outcome. Seventy-eight patients (49.7%) met criteria for a durable surgical result. Multivariable adjusted analysis identified the following independent predictors of surgical durability: surgical invasiveness >65, being fused to S1/pelvis, baseline to 6-week pelvic incidence and lumbar lordosis difference >13.9°, and having a proportional Global Alignment and Proportion score at 6 weeks. CONCLUSIONS: Nearly 50% of the ASD cohort demonstrated good surgical durability, with favorable radiographic alignment and functional status maintained up to 3 years. Surgical durability was more likely in patients whose reconstruction was fused to the pelvis and addressed lumbopelvic mismatch with adequate surgical invasiveness to achieve full alignment correction.

The Impact of Lumbopelvic Realignment Versus Prevention Strategies at the Upper-instrumented Vertebra on the Rates of Junctional Failure Following Adult Spinal Deformity Surgery.

STUDY DESIGN/SETTING: Retrospective. OBJECTIVE: Evaluate the surgical technique that has the greatest influence on the rate of junctional failure following ASD surgery. SUMMARY OF BACKGROUND DATA: Differing presentations of adult spinal deformity(ASD) may influence the extent of surgical intervention and the use of prophylaxis at the base or the summit of a fusion construct to influence junctional failure rates. MATERIALS AND METHODS: ASD patients with two-year(2Y) data and at least 5-level fusion to the pelvis were included. Patients were divided based on UIV: [Longer Construct: T1-T4; Shorter Construct: T8-T12]. Parameters assessed included matching in age-adjusted PI-LL or PT, aligning in GAP-relative pelvic version or Lordosis Distribution Index. After assessing all lumbopelvic radiographic parameters, the combination of realigning the two parameters with the greatest minimizing effect of PJF constituted a good base. Good s was defined as having: (1) prophylaxis at UIV (tethers, hooks, cement), (2) no lordotic change(under-contouring) greater than 10° of the UIV, (3) preoperative UIV inclination angle<30°. Multivariable regression analysis assessed the effects of junction characteristics and radiographic correction individually and collectively on the development of PJK and PJF in differing construct lengths, adjusting for confounders. RESULTS: In all, 261 patients were included. The cohort had lower odds of PJK(OR: 0.5,[0.2-0.9]; P =0.044) and PJF was less likely (OR: 0.1,[0.0-0.7]; P =0.014) in the presence of a good summit. Normalizing pelvic compensation had the greatest radiographic effect on preventing PJF overall (OR: 0.6,[0.3-1.0]; P =0.044). In shorter constructs, realignment had a greater effect on decreasing the odds of PJF(OR: 0.2,[0.02-0.9]; P =0.036). With longer constructs, a good summit lowered the likelihood of PJK(OR: 0.3,[0.1-0.9]; P =0.027). A good base led to zero occurrences of PJF. In patients with severe frailty/osteoporosis, a good summit lowered the incidence of PJK(OR: 0.4,[0.2-0.9]; P =0.041) and PJF (OR: 0.1,[0.01-0.99]; P =0.049). CONCLUSION: To mitigate junctional failure, our study demonstrated the utility of individualizing surgical approaches to emphasize an optimal basal construct. Achievement of tailored goals at the cranial end of the surgical construct may be equally important, especially for higher-risk patients with longer fusions. LEVEL OF EVIDENCE: 3.

The Predictive Potential of Nutritional and Metabolic Burden: Development of a Novel Validated Metric Predicting Increased Postoperative Complications in Adult Spinal Deformity Surgery.

STUDY DESIGN: A retrospective cohort review. OBJECTIVE: To develop a scoring system for predicting increased risk of postoperative complications in adult spinal deformity (ASD) surgery based on baseline nutritional and metabolic factors. BACKGROUND: Endocrine and metabolic conditions have been shown to adversely influence patient outcomes and may increase the likelihood of postoperative complications. The impact of these conditions has not been effectively evaluated in patients undergoing ASD surgery. MATERIALS AND METHODS: ASD patients 18 years or above with baseline and two-year data were included. An internally cross-validated weighted equation using preoperative laboratory and comorbidity data correlating to increased perioperative complications was developed via Poisson regression. Body mass index (BMI) categorization (normal, over/underweight, and obese) and diabetes classification (normal, prediabetic, and diabetic) were used per the Centers for Disease Control and Prevention and the American Diabetes Associates parameters. A novel ASD-specific nutritional and metabolic burden score (ASD-NMBS) was calculated via Beta-Sullivan adjustment, and Conditional Inference Tree determined the score threshold for experiencing ≥1 complication. Cohorts were stratified into low-risk and high-risk groups for comparison. Logistic regression assessed correlations between increasing burden score and complications. RESULTS: Two hundred one ASD patients were included (mean age: 58.60±15.4, sex: 48% female, BMI: 29.95±14.31, Charlson Comorbidity Index: 3.75±2.40). Significant factors were determined to be age (+1/yr), hypertension (+18), peripheral vascular disease (+37), smoking status (+21), anemia (+1), VitD hydroxyl (+1/ng/mL), BMI (+13/cat), and diabetes (+4/cat) (model: P <0.001, area under the curve: 92.9%). Conditional Inference Tree determined scores above 175 correlated with ≥1 post-op complication ( P <0.001). Furthermore, HIGH patients reported higher rates of postoperative cardiac complications ( P =0.045) and were more likely to require reoperation ( P =0.024) compared with low patients. CONCLUSIONS: The development of a validated novel nutritional and metabolic burden score (ASD-NMBS) demonstrated that patients with higher scores are at greater risk of increased postoperative complications and course. As such, surgeons should consider the reduction of nutritional and metabolic burden preoperatively to enhance outcomes and reduce complications in ASD patients.

The Importance of Incorporating Proportional Alignment in Adult Cervical Deformity Corrections Relative to Regional and Global Alignment: Steps Toward Development of a Cervical-Specific Score.

STUDY DESIGN/SETTING: Retrospective single-center study. BACKGROUND: The global alignment and proportion score is widely used in adult spinal deformity surgery. However, it is not specific to the parameters used in adult cervical deformity (ACD). PURPOSE: Create a cervicothoracic alignment and proportion (CAP) score in patients with operative ACD. METHODS: Patients with ACD with 2-year data were included. Parameters consisted of relative McGregor's Slope [RMGS = (MGS × 1.5)/0.9], relative cervical lordosis [RCL = CL - thoracic kyphosis (TK)], Cervical Lordosis Distribution Index (CLDI = C2 - Apex × 100/C2 - T2), relative pelvic version (RPV = sacral slope - pelvic incidence × 0.59 + 9), and a frailty factor (greater than 0.33). Cutoff points were chosen where the cross-tabulation of parameter subgroups reached a maximal rate of meeting the Optimal Outcome. The optimal outcome was defined as meeting Good Clinical Outcome criteria without the occurrence of distal junctional failure (DJF) or reoperation. CAP was scored between 0 and 13 and categorized accordingly: ≤3 (proportioned), 4-6 (moderately disproportioned), >6 (severely disproportioned). Multivariable logistic regression analysis determined the relationship between CAP categories, overall score, and development of distal junctional kyphosis (DJK), DJF, reoperation, and Optimal Outcome by 2 years. RESULTS: One hundred five patients with operative ACD were included. Assessment of the 3-month CAP score found a mean of 5.2/13 possible points. 22.7% of patients were proportioned, 49.5% moderately disproportioned, and 27.8% severely disproportioned. DJK occurred in 34.5% and DJF in 8.7%, 20.0% underwent reoperation, and 55.7% achieved Optimal Outcome. Patients severely disproportioned in CAP had higher odds of DJK [OR: 6.0 (2.1-17.7); P =0.001], DJF [OR: 9.7 (1.8-51.8); P =0.008], reoperation [OR: 3.3 (1.9-10.6); P =0.011], and lower odds of meeting the optimal outcome [OR: 0.3 (0.1-0.7); P =0.007] by 2 years, while proportioned patients suffered zero occurrences of DJK or DJF. CONCLUSION: The regional alignment and proportion score is a method of analyzing the cervical spine relative to global alignment and demonstrates the importance of maintaining horizontal gaze, while also matching overall cervical and thoracolumbar alignment to limit complications and maximize clinical improvement.

Outcomes and survival analysis of adult cervical deformity patients with 10-year follow-up.

BACKGROUND: 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.

Risk of spinal surgery among individuals who have been re-vascularized for coronary artery disease.

HYPOTHESIS: Revascularization is a more effective intervention to reduce future postop complications. METHODS: Patients undergoing elective spine fusion surgery were isolated in the PearlDiver database. Patients were stratified by having previous history of vascular stenting (Stent), coronary artery bypass graft (CABG), and no previous heart procedure (No-HP). Means comparison tests (chi-squared and independent samples t-tests, as appropriate) compared differences in demographics, diagnoses, and comorbidities. Binary logistic regression assessed the odds of 30-day and 90-day postoperative (postop) complications associated with each heart procedure (Odds Ratio [95 % confidence interval]). Statistical significance was set p < 0.05. RESULTS: 731,173 elective spine fusion patients included. Overall, 8,401 pts underwent a CABG, 24,037 pts Stent, and 698,735 had No-HP prior to spine fusion surgery. Compared to Stent and No-HP patients, CABG patients had higher rates of morbid obesity, chronic kidney disease, and diabetes (p < 0.001 for all). Meanwhile, stent patients had higher rates of PVD, hypertension, and hyperlipidemia (all p < 0.001). 30-days post-op, CABG patients had significantly higher complication rates including pneumonia, CVA, MI, sepsis, and death compared to No-HP (all p < 0.001). Stent patients vs. No-HF had higher 30-day post-op complication rates including pneumonia, CVA, MI, sepsis, and death. Furthermore, adjusting for age, comorbidities, and sex Stent was significantly predictive of a MI 30-days post-op (OR: 1.90 [1.53-2.34], P < 0.001). Additionally, controlling for levels fused, stent patients compared to CABG patients had 1.99x greater odds of a MI within 30-days (OR: 1.99 [1.26-3.31], p = 0.005) and 2.02x odds within 90-days postop (OR: 2.2 [1.53-2.71, p < 0.001). CONCLUSION: With regards to spine surgery, coronary artery bypass graft remains the gold standard for risk reduction. Stenting does not appear to minimize risk of experiencing a post-procedure cardiac event as dramatically as CABG.

The impact of baseline cervical malalignment on the development of proximal junctional kyphosis following surgical correction of thoracolumbar adult spinal deformity.

OBJECTIVE: The objective of this study was to identify the effect of baseline cervical deformity (CD) on proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in patients with adult spinal deformity (ASD). METHODS: This study was a retrospective analysis of a prospectively collected, multicenter database comprising ASD patients enrolled at 13 participating centers from 2009 to 2018. Included were ASD patients aged > 18 years with concurrent CD (C2-7 kyphosis < -15°, T1S minus cervical lordosis > 35°, C2-7 sagittal vertical axis > 4 cm, chin-brow vertical angle > 25°, McGregor's slope > 20°, or C2-T1 kyphosis > 15° across any three vertebrae) who underwent surgery. Patients were grouped according to four deformity classification schemes: Ames and Passias CD modifiers, sagittal morphotypes as described by Kim et al., and the head versus trunk balance system proposed by Mizutani et al. Mean comparison tests and multivariable binary logistic regression analyses were performed to assess the impact of these deformity classifications on PJK and PJF rates up to 3 years following surgery. RESULTS: A total of 712 patients with concurrent ASD and CD met the inclusion criteria (mean age 61.7 years, 71% female, mean BMI 28.2 kg/m2, and mean Charlson Comorbidity Index 1.90) and underwent surgery (mean number of levels fused 10.1, mean estimated blood loss 1542 mL, and mean operative time 365 minutes; 70% underwent osteotomy). By approach, 59% of the patients underwent a posterior-only approach and 41% underwent a combined approach. Overall, 277 patients (39.1%) had PJK by 1 year postoperatively, and an additional 189 patients (26.7%) developed PJK by 3 years postoperatively. Overall, 65 patients (9.2%) had PJF by 3 years postoperatively. Patients classified as having a cervicothoracic deformity morphotype had higher rates of early PJK than flat neck deformity and cervicothoracic deformity patients (p = 0.020). Compared with the head-balanced patients, trunk-balanced patients had higher rates of PJK and PJF (both p < 0.05). Examining Ames modifier severity showed that patients with moderate and severe deformity by the horizontal gaze modifier had higher rates of PJK (p < 0.001). CONCLUSIONS: In patients with concurrent cervical and thoracolumbar deformities undergoing isolated thoracolumbar correction, the use of CD classifications allows for preoperative assessment of the potential for PJK and PJF that may aid in determining the correction of extending fusion levels.

Surgical costs in adult cervical Deformity: Do higher cost surgeries lead to better Outcomes?

BACKGROUND: As our focus on delivering cost effective healthcare increases, interventions like cervical deformity surgery, which are associated with high resource utilization, have received greater scrutiny. The purpose of this study was to assess relationship between surgical costs, deformity correction, and patient reported outcomes in ACD surgery. METHODS: ACD Patients ≥ 18 years with baseline (BL) and 2-year (2Y) data were included. Cost of surgery was calculated by applying average Medicare reimbursement rates by CPT code to surgical details of each patient in the cohort. CPT codes for corpectomy, ACDF, osteotomy, decompression, levels fused, and instrumentation were considered in the analysis. Costs of complications and reoperations were intentionally excluded from the cost analysis. Patients were ranked into two groups by surgical cost: lowest cost (LC) and highest cost (HC). ANCOVA assessed differences in outcomes while accounting for covariates as appropriate. RESULTS: 113 met inclusion criteria. While mean age, frailty, BMI and gender composition were similar between cost groups, mean CCI was significantly higher in the HC group compared to that of the LC group (p=.014). At baseline, LC and HC groups had similar HRQLs and radiographic deformity (all p >.05). Logistic regression accounting for baseline age, deformity and CCI found that HC patients had significantly lower odds of undergoing reoperation within 2-years (OR: 0.309, 95 % CI: 0.193 - 0.493, p <.001). Furthermore, logistic regression accounting for baseline age, deformity and CCI found odds of DJF were significantly lower for those in the HC group (OR: 0.163, 95 % CI: 0.083 - 0.323, p <.001). At 2-years, logistic regression accounting for age and baseline TS-CL found HC patients still had significantly higher odds of reaching a "0″ TS-CL modifier at 2-years (OR: 3.353, 95 % CI: 1.081 - 10.402, p=.036). Logistic regression accounting for age and baseline NDI score found HC patients had significantly higher odds of reaching MCID in NDI at 2-years (OR: 4.477, 95 % CI: 1.507 - 13.297, p=.007). A similar logistic regression accounting for age and baseline mJOA score found odds of reaching MCID in mJOA significantly higher for high-cost patients (OR: 2.942, 95 % CI: 1.101 - 7.864, p=.031). CONCLUSIONS: While patient presentation influences surgical planning and costs, this study attempted to control for such variations to assess impact of surgical costs on outcomes. Despite continued scrutiny over healthcare costs, we found that more costly surgical interventions can produce superior radiographic alignment as well as patient reported outcomes for patients with cervical deformity.

Impact of Frailty on the Development of Proximal Junctional Failure: Does Frailty Supersede Achieving Optimal Realignment?

BACKGROUND: 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.

Concurrent Presence of Thoracolumbar Scoliosis and Chiari Malformation: Is Operative Risk Magnified?

STUDY DESIGN: Retrospective review of Kids' Inpatient Database (KID). PURPOSE: Identify the risks and complications associated with surgery in adolescents diagnosed with Chiari and scoliosis. OVERVIEW OF LITERATURE: Scoliosis is frequently associated with Chiari malformation (CM). More specifically, reports have been made about this association with CM type I in the absence of syrinx status. METHODS: The KID was used to identify all pediatric inpatients with CM and scoliosis. The patients were stratified into three groups: those with concomitant CM and scoliosis (CMS group), those with only CM (CM group), and those with only scoliosis (Sc group). Multivariate logistic regressions were used to assess association between surgical characteristics and diagnosis with complication rate. RESULTS: A total of 90,707 spine patients were identified (61.8% Sc, 37% CM, 1.2% CMS). Sc patients were older, had a higher invasiveness score, and higher Charlson comorbidity index (all p<0.001). CMS patients had significantly higher rates of surgical decompression (36.7%). Sc patients had significantly higher rates of fusions (35.3%) and osteotomies (1.2%, all p<0.001). Controlling for age and invasiveness, postoperative complications were significantly associated with spine fusion surgery for Sc patients (odds ratio [OR], 1.8; p<0.05). Specifically, posterior spinal fusion in the thoracolumbar region had a greater risk of complications (OR, 4.9) than an anterior approach (OR, 3.6; all p<0.001). CM patients had a significant risk of complications when an osteotomy was performed as part of their surgery (OR, 2.9) and if a spinal fusion was concurrently performed (OR, 1.8; all p<0.05). Patients in the CMS cohort were significantly likely to develop postoperative complications if they underwent a spinal fusion from both anterior (OR, 2.5) and posterior approach (OR, 2.7; all p<0.001). CONCLUSIONS: Having concurrent scoliosis and CM increases operative risk for fusion surgeries despite approach. Being independently inflicted with scoliosis or Chiari leads to increased complication rate when paired with thoracolumbar fusion and osteotomies; respectively.

Natural history of adult spinal deformity: how do patients with suboptimal surgical outcomes fare relative to nonoperative counterparts?

OBJECTIVE: 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.

Long-term Morbidity in Patients After Surgical Correction of Adult Spinal Deformity: Results From a Cohort With Minimum 5-year Follow-up.

STUDY 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.

A Hierarchical Approach to Realignment Strategies in Adult Cervical Deformity Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Construct an individualized cervical realignment strategy based on patient parameters at the presentation that results in superior 2-year health-related quality of life metrics and decreased rates of junctional failure and reoperation following adult cervical deformity surgery. SUMMARY OF BACKGROUND DATA: Research has previously focused on adult cervical deformity realignment thresholds for maximizing clinical outcomes while minimizing complications. However, realignment strategies may differ based on patient presentation and clinical characteristics. METHODS: We included adult cervical deformity patients with 2-year data. The optimal outcome was defined as meeting good clinical outcomes without distal junctional failure or reoperation. Radiographic parameters assessed included C2 Slope, C2-C7, McGregor's slope, TS-CL, cSVA, T1 slope, and preoperative lowest-instrumented vertebra (LIV) inclination angle. Conditional inference trees were used to establish thresholds for each parameter based on achieving the optimal outcome. Analysis of Covariance and multivariable logistic regression analysis, controlling for age, comorbidities, baseline deformity and disability, and surgical factors, assessed outcome rates for the hierarchical approach within each deformity group. RESULTS: One hundred twenty-seven patients were included. After correction, there was a significant difference in meeting the optimal outcome when correcting the C2 slope below 10 degrees (85% vs. 34%, P <0.001), along with lower rates of distal junctional failure (DJF) (7% vs. 42%, P <0.001). Next, after isolating patients below the C2 slope threshold, the selection of LIV with an inclination between 0 and 40 degrees demonstrated lower rates of distal junctional kyphosis and higher odds of meeting optimal outcome(OR: 4.2, P =0.011). The best third step was the correction of cSVA below 35 mm. This hierarchical approach (11% of the cohort) led to significantly lower rates of DJF (0% vs. 15%, P <0.007), reoperation (8% vs. 28%, P <0.001), and higher rates of meeting optimal outcome (93% vs. 36%, P <0.001) when controlling for age, comorbidities, and baseline deformity and disability. CONCLUSION: Our results indicate that the correction of C2 slope should be prioritized during cervical deformity surgery, with the selection of a stable LIV and correction of cervical SVA below the idealized threshold. Among the numerous radiographic parameters considered during preoperative planning for cervical deformity correction, our determinations help surgeons prioritize those realignment strategies that maximize the health-related quality of life outcomes and minimize complications. LEVEL OF EVIDENCE: Level-III.