Adult Cervical Deformity Surgery Research Articles

Lower Hounsfield Units at the Planned Lowest Instrumented Vertebra is an Independent Risk Factor for Complications Following Adult Cervical Deformity Surgery.

The association of Hounsfield units (HU) and junctional pathologies in adult cervical deformity (ACD) surgery has not been elucidated. Assess if the bone mineral density of the LIV, as assessed by HUs, is prognostic for the risk of complications after ACD surgery. Retrospective cohort study. HUs were measured on preoperative CT scans. Means comparison test assessed differences in HUs based on the occurrence of complications, linear regression assessed the correlation of HUs with risk factors, and multivariable logistic regression followed by a conditional inference tree derived a threshold for HUs based on the increased likelihood of developing a complication. In all, 107 ACD patients were included. Thirty-one patients (29.0%) developed a complication (18.7% perioperative), with 20.6% developing DJK and 11.2% developing DJF. There was a significant correlation between lower LIVs and lower HUs (r=0.351, P=0.01), as well as age and HUs at the LIV. Age did not correlate with change in the DJK angle (P>0.2). HUs were lower at the LIV for patients who developed a complication and an LIV threshold of 190 HUs was predictive of complications (OR: 4.2, [1.2-7.6]; P=0.009). Low bone mineral density at the lowest instrumented vertebra, as assessed by a threshold lower than 190 Hounsfield units, may be a crucial risk factor for the development of complications after cervical deformity surgery. Preoperative CT scans should be routinely considered in at-risk patients to mitigate this modifiable risk factor during surgical planning. Level-III.

The Evolution of Enhanced Recovery After Surgery: Assessing the Clinical Benefits of Developments Within Enhanced Recovery After Surgery Protocols in Adult Cervical Deformity Surgery.

Retrospective cohort. To investigate the impact of evolving Enhanced Recovery After Surgery (ERAS) protocols on outcomes after cervical deformity (CD) surgery. ERAS can help accelerate patient recovery and assist hospitals in maximizing the incentives of bundled payment models while maintaining high-quality patient care. However, there remains a paucity of literature assessing how developments have impacted outcomes after adult CD surgery. Patients with operative CD 18 years or older with pre-baseline and 2 years (2Y) postoperative data, who underwent ERAS protocols, were stratified by increasing implantation of ERAS components: (1) early (multimodal pain program), (2) intermediate (early protocol + paraspinal blocks, early ambulation), and (3) late (early/intermediate protocols + comprehensive prehabilitation). Differences in demographics, clinical outcomes, radiographic alignment targets, perioperative factors, and complication rates were assessed through Bonferroni-adjusted means comparison analysis. A total of 131 patients were included (59.4 ± 11.7 y, 45% females, 28.8 ± 6.0 kg/m 2 ). Of these patients, 38.9% were considered "early," 36.6% were "intermediate," and 24.4% were "late." Perioperatively, rates of intraoperative complications were lower in the late group ( P = 0.036). Postoperatively, discharge disposition differed significantly between cohorts, with late patients more likely to be discharged to home versus early or intermediate cohorts [χ 2 (2) = 37.973, P < 0.001]. In terms of postoperative disability recovery, intermediate and late patients demonstrated incrementally improved 6 W modified Japanese Orthopedic Association scores ( P = 0.004), and late patients maintained significantly higher mean Euro-QOL 5-Dimension Questionnaire and modified Japanese Orthopedic Association scores by 1 year ( P < 0.001, P = 0.026). By 2Y, cohorts demonstrated incrementally increasing SWAL-QOL scores (all domains P < 0.028) domain scores versus early or intermediate cohorts. By 2Y, incrementally decreasing reoperation was observed in early versus intermediate versus late cohorts ( P = 0.034). The present study demonstrates that patients enrolled in an evolving ERAS program demonstrate incremental improvement in preoperative optimization and candidate selection, greater likelihood of discharge to home, decreased postoperative disability and dysphasia burden, and decreased likelihood of intraoperative complications and reoperation rates.

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

Retrospective cohort study. To assess the impact of Enhanced recovery after surgery (ERAS) protocols on peri-operative course in adult cervical deformity (ACD) corrective surgery. 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. 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). Enhanced recovery after surgery programs in ACD surgery demonstrate significant benefit in terms of peri-operative outcomes for patients.

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

To investigate the effect of a prehabilitation program on peri- and post-operative outcomes in adult cervical deformity (CD) surgery. Operative CD patients ≥ 18years 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. 115 patients were included (age: 61years, 70% female, BMI: 28kg/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). 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.

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

BACKGROUNDPrevious 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. PURPOSETo 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/SETTINGRetrospective review. PATIENT SAMPLETwo hundred ninety ACD patients. OUTCOME MEASURESMorbidity and mortality data. METHODSOperative 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. RESULTSSixty-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). CONCLUSIONSOur 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.

138. Evolution of osteotomy techniques over time in adult cervical deformity surgery: impact of new technologies and techniques on patient outcomes

138. Evolution of osteotomy techniques over time in adult cervical deformity surgery: impact of new technologies and techniques on patient outcomes

P98. Predicting 2-year health-related quality of life improvement in adult cervical deformity surgery

P98. Predicting 2-year health-related quality of life improvement in adult cervical deformity surgery

206. Comparative analysis of the occurrence and clinical impact of dramatic global kyphosis in the unfused thoracic spine relative to distal junctional failure following adult cervical deformity surgery

206. Comparative analysis of the occurrence and clinical impact of dramatic global kyphosis in the unfused thoracic spine relative to distal junctional failure following adult cervical deformity surgery

204. Analysis of cost utility of distal junctional kyphosis occurrence after adult cervical deformity surgery: the benefit of prophylaxis and preoperative optimization

204. Analysis of cost utility of distal junctional kyphosis occurrence after adult cervical deformity surgery: the benefit of prophylaxis and preoperative optimization

134. Cost-benefit analysis of preoperative optimization of modifiable health conditions prior to adult cervical deformity surgery

134. Cost-benefit analysis of preoperative optimization of modifiable health conditions prior to adult cervical deformity surgery

86. Optimizing modifiable health conditions prior to adult cervical deformity surgery associated with fewer complications

86. Optimizing modifiable health conditions prior to adult cervical deformity surgery associated with fewer complications

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

Retrospective cohort study. 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. 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. 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. 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 35mm. 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. 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-III.

Preventing distal junctional kyphosis: Choosing a stable end for the lowest-instrumented vertebra is protective following adult cervical deformity surgery

Preventing distal junctional kyphosis: Choosing a stable end for the lowest-instrumented vertebra is protective following adult cervical deformity surgery

P63. Assessing the effects of prehabilitation protocols on postoperative outcomes in adult cervical deformity surgery: does early optimization lead to optimal clinical outcomes?

BACKGROUND CONTEXT Previous studies have demonstrated that preoperative rehabilitation (prehab) may be beneficial in adult cervical deformity surgery. Though protocols vary widely, general overlap exists in terms of inclusion of mental and physical modalities in order to optimize patient outcomes. However, there remains a paucity of literature in regards to assessing outcomes in a controlled setting. PURPOSE To assess the effects of prehabilitation on peri- and postoperative outcomes in adult cervical deformity surgery. STUDY DESIGN/SETTING Retrospective review of prospective CD database. PATIENT SAMPLE A total of 290 CD patients. OUTCOME MEASURES Peri- and postoperative complication rates; medication usage; HRQLs. METHODS Operative CD patients 18yrs with complete pre-(BL) and 2-year(2Y) postop radiographic/HRQL data were stratified by enrollment in prehabilitation protocols beginning in 2019, consisting of physical therapy, nutritional counseling and/or psychological counseling. Patients were stratified as having underwent prehabilitation (Prehab+), versus those who did not (Prehab-). Differences in demographics, clinical outcomes, radiographic alignment targets, perioperative factors and complication rates were assessed via means comparison analysis. Costs were calculated using PearlDiver database estimates from Medicare pay-scales. QALY was calculated via NDI mapped to SF6D using validated methods. RESULTS A total of 115 patients were included (56.37±8.90 years, 38% female, 29.84±6.19 kg/m2). Of these patients, 57 (49.6%) were classified as Prehab+. At baseline, groups were comparable in age, gender, BMI, CCI and frailty. In terms of BL HRQLs, Prehab+ significantly lower mJOA scores (p=.047), though were equivalent in NDI and EQ5D scores (both p>.05). Baseline opioid usage was comparable prior to prehab enrollment (p=.093). Surgically, Prehab+ were able to undergo longer procedures (p=.017) with equivalent EBL (p=.627), and shorter SICU stay (p.05) and QALYs gained by 2Y (.43 vs .40, p>.05). CONCLUSIONS This study demonstrates that introducing prehabilitation protocols in adult cervical deformity surgery may aid in improving patient physiological status, enabling them to undergo longer surgeries with lessened risk of peri- and postoperative complications. Though cost-effectiveness of such programs should be further assessed, prehabilitation should be considered for eligible patients to assist in optimizing recovery and reducing complications or reoperations. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Previous studies have demonstrated that preoperative rehabilitation (prehab) may be beneficial in adult cervical deformity surgery. Though protocols vary widely, general overlap exists in terms of inclusion of mental and physical modalities in order to optimize patient outcomes. However, there remains a paucity of literature in regards to assessing outcomes in a controlled setting. To assess the effects of prehabilitation on peri- and postoperative outcomes in adult cervical deformity surgery. Retrospective review of prospective CD database. A total of 290 CD patients. Peri- and postoperative complication rates; medication usage; HRQLs. Operative CD patients 18yrs with complete pre-(BL) and 2-year(2Y) postop radiographic/HRQL data were stratified by enrollment in prehabilitation protocols beginning in 2019, consisting of physical therapy, nutritional counseling and/or psychological counseling. Patients were stratified as having underwent prehabilitation (Prehab+), versus those who did not (Prehab-). Differences in demographics, clinical outcomes, radiographic alignment targets, perioperative factors and complication rates were assessed via means comparison analysis. Costs were calculated using PearlDiver database estimates from Medicare pay-scales. QALY was calculated via NDI mapped to SF6D using validated methods. A total of 115 patients were included (56.37±8.90 years, 38% female, 29.84±6.19 kg/m2). Of these patients, 57 (49.6%) were classified as Prehab+. At baseline, groups were comparable in age, gender, BMI, CCI and frailty. In terms of BL HRQLs, Prehab+ significantly lower mJOA scores (p=.047), though were equivalent in NDI and EQ5D scores (both p>.05). Baseline opioid usage was comparable prior to prehab enrollment (p=.093). Surgically, Prehab+ were able to undergo longer procedures (p=.017) with equivalent EBL (p=.627), and shorter SICU stay (p.05) and QALYs gained by 2Y (.43 vs .40, p>.05). This study demonstrates that introducing prehabilitation protocols in adult cervical deformity surgery may aid in improving patient physiological status, enabling them to undergo longer surgeries with lessened risk of peri- and postoperative complications. Though cost-effectiveness of such programs should be further assessed, prehabilitation should be considered for eligible patients to assist in optimizing recovery and reducing complications or reoperations.

P113. At what point does degenerative become deformity: when good outcomes necessitate sagittal correction in adult cervical deformity surgery

BACKGROUND CONTEXT Current radiographic thresholds have shown inconsistent correlation with clinical outcomes. However, it has not been determined at what point in presenting deformity does sagittal correction tremendously improve clinical outcomes following cervical deformity surgery. PURPOSE Define baseline thresholds in cervical parameters that, when exceeded, benefit dramatically from surgical correction to achieve ideal clinical outcomes. STUDY DESIGN/SETTING Retrospective. PATIENT SAMPLE A total of 290 ACD patients. OUTCOME MEASURES Clinical outcomes, radiographic alignment. METHODS CD patients with baseline (BL) and 2-year (2Y) data included. Parameters assessed: C2 slope (C2S), C2-C7 Lordosis, C2-C7 SVA (cSVA), T1 Slope (T1S), TS-CL. Outcomes: Virket al Good Clinical Outcome (GCO): [Meeting 2 of 3: 1) an NDI>20 or meeting MCID, 2) mJOA >=14), 3) an NRS-Neck<=5 or improved by 2 or more points from baseline]. Binary logistic regression assessed each parameter to determine if correction was more likely needed to achieve GCO. Conditional inference tree (CIT) run machine learning analysis generated baseline thresholds for each parameter, above which, correction was necessary to achieve GCO. RESULTS Included: 105 CD patients. There were 57 (54%) of patients achieving GCO by 2Y. Correction was necessitated when baseline C2S was above 20° (OR: 6.8, [1.6-28.9]; p=.01) and when baseline C2-C7 Lordosis was below 10° (OR: 16, [2.4-107.5]; p=.004). Patients presenting with a cSVA above 20 mm more often achieved clinical success when corrected (74.2% vs 0.0%, p<.001). A baseline T1 slope above 23° was 16 times more likely to reach GCO with correction than those below this threshold (p=.005). TS-CL more likely required correction to reach GCO when above 26° at baseline (OR: 7.0, [1.7-29.1]; p=.007). When assessing patients above both the cSVA and C2S threshold versus the remaining cohort, these patients more likely met GCO when corrected in either parameter (OR: 22.5, [3.3-152.0]; p=.001). CONCLUSIONS Our study highlighted the importance of correction and the threshold at which it dramatically impacts clinical success. These new thresholds delineate patients obtaining superior benefit for sagittal correction and may better increase the utility gained from surgical intervention for cervical deformity. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Current radiographic thresholds have shown inconsistent correlation with clinical outcomes. However, it has not been determined at what point in presenting deformity does sagittal correction tremendously improve clinical outcomes following cervical deformity surgery. Define baseline thresholds in cervical parameters that, when exceeded, benefit dramatically from surgical correction to achieve ideal clinical outcomes. Retrospective. A total of 290 ACD patients. Clinical outcomes, radiographic alignment. CD patients with baseline (BL) and 2-year (2Y) data included. Parameters assessed: C2 slope (C2S), C2-C7 Lordosis, C2-C7 SVA (cSVA), T1 Slope (T1S), TS-CL. Outcomes: Virket al Good Clinical Outcome (GCO): [Meeting 2 of 3: 1) an NDI>20 or meeting MCID, 2) mJOA >=14), 3) an NRS-Neck<=5 or improved by 2 or more points from baseline]. Binary logistic regression assessed each parameter to determine if correction was more likely needed to achieve GCO. Conditional inference tree (CIT) run machine learning analysis generated baseline thresholds for each parameter, above which, correction was necessary to achieve GCO. Included: 105 CD patients. There were 57 (54%) of patients achieving GCO by 2Y. Correction was necessitated when baseline C2S was above 20° (OR: 6.8, [1.6-28.9]; p=.01) and when baseline C2-C7 Lordosis was below 10° (OR: 16, [2.4-107.5]; p=.004). Patients presenting with a cSVA above 20 mm more often achieved clinical success when corrected (74.2% vs 0.0%, p<.001). A baseline T1 slope above 23° was 16 times more likely to reach GCO with correction than those below this threshold (p=.005). TS-CL more likely required correction to reach GCO when above 26° at baseline (OR: 7.0, [1.7-29.1]; p=.007). When assessing patients above both the cSVA and C2S threshold versus the remaining cohort, these patients more likely met GCO when corrected in either parameter (OR: 22.5, [3.3-152.0]; p=.001). Our study highlighted the importance of correction and the threshold at which it dramatically impacts clinical success. These new thresholds delineate patients obtaining superior benefit for sagittal correction and may better increase the utility gained from surgical intervention for cervical deformity.

222. Development of a hierarchical approach to surgical planning in adult cervical deformity surgery

<h3>BACKGROUND CONTEXT</h3> Research has been concentrated on cervical deformity realignment thresholds for achieving desired clinical outcomes while decreasing worrisome complications, like distal junctional failure (DJF) and reoperation. The present study aims to establish a hierarchical order for realignment of spinopelvic parameters during ACD surgery. <h3>PURPOSE</h3> Develop a hierarchical order to cervical parameter realignment produces better 2-year HRQL metrics and decrease the risk of junctional failure during ACD surgery. <h3>STUDY DESIGN/SETTING</h3> Retrospective. <h3>PATIENT SAMPLE</h3> A total of 290 ACD patients. <h3>OUTCOME MEASURES</h3> Clinical outcomes, distal junctional failure, reoperation, radiographic realignment. <h3>METHODS</h3> Included: operative CD patients with up to 2-year (2Y) HRQL data. Outcome variables: distal junctional kyphosis (DJK) and failure (DJF); reoperation; and Virk et al good clinical outcome((meeting 2 of 3: NDI>20 or meeting MCID, mJOA >=14), NRS-Neck<=5 or improved by 2 or more points from baseline). Optimal outcome was defined as meeting good clinical outcome without developing DJF or undergoing reoperation. Descriptive analysis identified cohort demographics and radiographic parameters (C2 Slope, Cervical Lordosis, McGregor's Slope, TS-CL, cSVA, T1 slope). Using conditional inference tree (CIT) analysis, thresholds for each parameter were derived based on meeting optimal outcome. Patients meeting the best performing threshold in terms of optimal outcome were isolated and the threshold derivation was repeated for the remaining parameters. ANCOVA, controlling for age and baseline deformity, assessed outcome rates in patients meeting the hierarchical realignment. <h3>RESULTS</h3> A total of 133 ACD patients (61.8±9.9yrs, 27.6±5.8 kg/m2, CCI: 1.0±1.4, CD-FI: 0.4±0.1) who underwent surgery (7.6±4.0 levels fused, EBL: 781±853 mL, op time: 383±218 min, LOS: 5.9±4.4 days) were included. Twenty percent underwent an anterior approach, 46% posterior, 34% combined. Decompressions were performed in 52%, 83% underwent an osteotomy. After correction, there was a significant difference in meeting optimal outcome when correcting C2 Slope below 10° (85% vs 34%, p< .001), along with lower rates of DJF (7% vs 42%, p <.001). Next, after isolating patients above the C2 slope threshold, correction of T1 slope below 26° demonstrated lower rates of DJK and higher odds of meeting optimal outcome (OR: 4.2, p=.011). The best third step was correction of cSVA below 35mm.This hierarchical approach (11% of cohort) led to significantly lower rates of DJF (0% vs 15%, p<.007), reoperation (8% vs 28%, p < .001), and higher rates of meeting optimal outcome (93% vs 36%, p < .001), and maintained significance after controlling for age and baseline deformity. <h3>CONCLUSIONS</h3> This ordered realignment of cervical parameters has demonstrated strong correlation to HRQL metrics and complications. Correction of C2 slope should be prioritized during cervical deformity surgery, with subsequent correction of T1 slope and cervical SVA below the derived thresholds. Amongst the numerous radiographic parameters used in cervical deformity, these findings help the surgeon prioritize realignment in certain parameters to achieve successful outcomes. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

P59. Predictive survival analysis of adult cervical deformity patients with 10-year follow-up

<h3>BACKGROUND CONTEXT</h3> Previous studies have demonstrated that adult cervical deformity patients may be at increased risk of death in conjunction with increased frailty or weakened physiologic state. However, such studies have often been limited to two years, and longer-term studies are needed to better assess temporal changes in CD patients and associated mortality risk. <h3>PURPOSE</h3> 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. <h3>STUDY DESIGN/SETTING</h3> Retrospective review of prospective cervical deformity (CD) database <h3>PATIENT SAMPLE</h3> A total of 290 CD patients. <h3>OUTCOME MEASURES</h3> Demographic factors; baseline comorbidities; intra/postoperative complications; mortality. <h3>METHODS</h3> Operative CD patients 18yrs with pre-(BL) and 10-year (10Y) data were included. Patients were stratified as Expired vs 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. <h3>RESULTS</h3> Sixty-six total patients were included (58.11 ± 11.97 years, 48% female, 29.13 ± 6.89 kg/m2). Within 10Y, 20 (27.3% of CD cohort). 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.001). KM analysis found that by Passias et al., frailty, not frail patients had mean survival time of 170.56 weeks, vs 158.00 in frail patients (p=.949). <h3>CONCLUSIONS</h3> This 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 CD patients in increasing their survivability post-operatively. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Predicting development of severe clinically relevant distal junctional kyphosis following adult cervical deformity surgery, with further distinction from mild asymptomatic episodes.

This retrospective cohort study aimed to develop a formal predictive model distinguishing between symptomatic and asymptomatic distal junctional kyphosis (DJK). In this study the authors identified a DJK rate of 32.2%. Predictive models were created that can be used with high reliability to help distinguish between severe symptomatic DJK and mild asymptomatic DJK through the use of surgical factors, radiographic parameters, and patient variables. Patients with cervical deformity (CD) were stratified into asymptomatic and symptomatic DJK groups. Symptomatic: 1) DJK angle (DJKA) > 10° and either reoperation due to DJK or > 1 new-onset neurological sequela related to DJK; or 2) either a DJKA > 20° or ∆DJKA > 20°. Asymptomatic: ∆DJK > 10° in the absence of neurological sequelae. Stepwise logistic regressions were used to identify factors associated with these types of DJK. Decision tree analysis established cutoffs. A total of 99 patients with CD were included, with 32.2% developing DJK (34.3% asymptomatic, 65.7% symptomatic). A total of 37.5% of asymptomatic patients received a reoperation versus 62.5% symptomatic patients. Multivariate analysis identified independent baseline factors for developing symptomatic DJK as follows: pelvic incidence (OR 1.02); preoperative cervical flexibility (OR 1.04); and combined approach (OR 6.2). Having abnormal hyperkyphosis in the thoracic spine, more so than abnormal cervical lordosis, was a factor for developing symptomatic disease when analyzed against asymptomatic patients (OR 1.2). Predictive modeling identified factors that were predictive of symptomatic versus no DJK, as follows: myelopathy (modified Japanese Orthopaedic Association score 12-14); combined approach; uppermost instrumented vertebra C3 or C4; preoperative hypermobility; and > 7 levels fused (area under the curve 0.89). A predictive model for symptomatic versus asymptomatic disease (area under the curve 0.85) included being frail, T1 slope minus cervical lordosis > 20°, and a pelvic incidence > 46.3°. Controlling for baseline deformity and disability, symptomatic patients had a greater cervical sagittal vertical axis (4-8 cm: 47.6% vs 27%) and were more malaligned according to their Scoliosis Research Society sagittal vertical axis measurement (OR 0.1) than patients without DJK at 1 year (all p < 0.05). Despite their symptomatology and higher reoperation rate, outcomes equilibrated in the symptomatic cohort at 1 year following revision. Overall, 32.2% of patients with CD suffered from DJK. Symptomatic DJK can be predicted with high reliability. It can be further distinguished from asymptomatic occurrences by taking into account pelvic incidence and baseline cervicothoracic deformity severity.

At what point does degenerative become deformity: When good outcomes necessitate sagittal correction in adult cervical deformity surgery

At what point does degenerative become deformity: When good outcomes necessitate sagittal correction in adult cervical deformity surgery

128. Evolution of adult cervical deformity surgery clinical and radiographic outcomes based on a multicenter prospective study: Are behaviors and outcomes changing with experience?

<h3>BACKGROUND CONTEXT</h3> With an aging population and increased prevalence of cervical deformity, corrective surgery is increasingly utilized as a treatment option. The goal of this study is to examine whether surgical advancements and expansion of knowledge over the years have improved or changed outcomes and the way we approach cervical deformity surgery. <h3>PURPOSE</h3> To investigate if outcomes or surgical approach have changed over time. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study of a prospective adult cervical deformity (ACD) database. <h3>PATIENT SAMPLE</h3> This study included 119 ACD patients. <h3>OUTCOME MEASURES</h3> Complications after ACD surgery within 2 years, HRQL (NDI, mJOA, EQ5D) <h3>Methods</h3> ACD patients (≥18 years) with complete baseline and 2-year HRQL and radiographic data were included. Descriptive analysis included demographics, radiographic, and surgical details. Patients were grouped into Group I (2013-2014) and Group II (2015-2017) by DOS. Univariate, and multivariate analysis determined differences in surgical, radiographic, and clinical outcomes between groups. <h3>Results</h3> A total of 119 cervical deformity patients met inclusion criteria (61.3years, 67%F, BMI: 29kg/m2, CCI: 0.96±1.3). Radiographically at baseline, patients presented with: PT: 18.8± 11.3; PI: 53.0±11.1; PI-LL: -.45±17.7; SVA:-4.34±66.8, TS-CL: 38.1 ±21.4; cSVA: 45.2±25.6. Surgically, 51.3% had osteotomies, 47.1% had a posterior approach, 34.5% combined approach, 18.5% anterior approach, with 7.6± 3.8 levels fused and EBL of 824 mL. Group I consisted of 72 patients, and Group II consisted of 47. Group II had a higher CCI (1.3 vs .72), more cerebrovascular disease (6% vs 0%, both p<0.05), and no difference in age, frailty, deformity, or cervical rigidity. Group II had a lower surgical invasiveness (9 vs 11, p<0.05), trended towards a lower EBL (677 vs 921, p=.124) and shorter LOS (5.1 vs 7.9, p=.065), with no difference in levels fused, approach, reoperations, DJK development, or HRQLs (p>0.05). Controlling for baseline deformity and age, patients in Group II underwent fewer three-column osteotomies .17[.04-.8], (p<0.05). Patients undergoing three-column osteotomies had a deformity primarily in the CT region (48%), followed by C (23%) and T (19%) with a similar distribution between Groups (p>0.05). Additionally, controlling for levels fused and three-column osteotomies, Group II experienced fewer minor complications .3[.09-.96], (p<0.05). At 2 years, Group II had fewer patients with a moderate/high Ames horizontal modifier (71.7% vs 88.2%), fewer patients who were overcorrected in PT (4.3% vs 18.1%) and fewer patients with a +, or ++ deformity in PT SRS-Schwab (9.1% vs 39.5%). In a site-specific subanalysis, controlling for age, CCI, baseline deformity, and levels fused, Group II experienced fewer adverse events than Group I .138[.027-.713], (p= .018). <h3>Conclusions</h3> Despite operating on a higher risk cohort with more comorbidity, outcomes have remained consistent, indicating improvements in care. Surgically, there has been a reduction in the number of three-column osteotomies performed, suboptimal realignments, and fewer complications and adverse events. This suggests a better understanding of minimizing the risk of cervical deformity surgery with fewer invasive techniques. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.