Faculty Bibliography

OBJECTIVE:While health-related quality of life (HRQOL) measures have been extensively quantified in cervical deformity (CD), this clinical dimension has not yet been fully integrated into understanding CD radiographic subtypes prior to surgery. The aim of this study was to identify distinct patterns of HRQOL deficits among patients with CD by focusing on clinical scores and to examine the association of these patterns with radiographic morphotypes of CD. METHODS:This was a retrospective analysis of a prospective multicenter database of patients with CD aged 18 years or older. Patient-reported outcome measures consisted of the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) scale, and Swallowing Quality of Life (SWAL-QOL) questionnaire. After performing a principal component analysis on the individual questions of the NDI, mJOA, and SWAL-QOL, 4 factors with eigenvalues > 1 were retained and included in a cluster analysis to assign patients into homogeneous groups of outcomes. Moreover, a subgroup of patients with severe deformity was described and analyzed. RESULTS:Overall, 134 patients (59% female, mean age ± SD 60.9 ± 10.8 years) were included in this analysis. The mean HRQOL scores were NDI, 49.1 ± 17.6; mJOA, 13.5 ± 2.7; and EQ-5D, 0.7 ± 0.1). The factor analysis involving NDI, SWAL-QOL, and mJOA revealed 4 clusters. Cluster A represented patients with a predominant sleep problem. Cluster B was patients with the lowest neck disability. Cluster C represented the most disabled patients in terms of dysphagia and neck disability. Cluster D represented patients with myelopathy. Among the 71 patients with severe deformity, the distribution of cervical morphotypes significantly differed across the 4 clusters of disability (p = 0.009). Cluster C mainly consisted of patients with cervicothoracic deformity (66.7%, p = 0.002). Cluster D had a large proportion of patients (66.7%) with focal deformity (p = 0.007). In clusters A and B, 57.9% and 46.4% of patients, respectively, presented with "flat neck" deformity (p = 0.02). CONCLUSIONS:Distinct patterns of HRQOL deficits were observed across a heterogeneous population of patients with CD, and these patterns were associated with specific radiographic morphotypes. These findings provide a framework for the next generation of CD classification, wherein HRQOL measures are combined with radiographic parameters.

STUDY DESIGN/METHODS:Retrospective cohort. OBJECTIVE:The ISSG-AO Spinal Deformity Complication Classification System (SDCCS) predicts Diagnosis Related Group (DRG) coding and cost. BACKGROUND:Inconsistent definitions of complications contribute to variation in reported surgical complication rates. Incorrect complication reporting can lead to over or under DRG reimbursement. The ISSG-AO SDCCS provides improved complication reporting reproducibility and may help predict complication costs. METHODS:ASD patients were grouped into: DRG without complication or comorbidity (CC) or Major CC (MCC) (DRGs 455 & 458), with CC (DRGs 454 & 457), and with MCC (DRGs 453 & 456). Complications were graded by intervention severity per ISSG-AO system: grade 0 (none), 1 (mild-e.g., med change), 2 (moderate-e.g., ICU), 3 (severe-e.g., reoperation). Cost were based on Medicare inpatient prospective payment system (IPSS, Medicare Allowable rate). A multinomial logistic model identified key predictors of DRG assignment by complication grades. RESULTS:Of the 675 patients, 14% were in DRGs without CC/MCC, 71% in DRGs with CC, and 15% were DRGs with MCC. Patients with complications requiring intervention mostly fell into the higher DRG categories (97%). Patients who received an intervention are approximately 6.75 (2.01-22.75, P<.0021) times more likely to be classified under DRG with CC and 15.72 (95% CI, 4.23-58.45, P<.0001) times more likely to be classified with DRG with MCC compared to those who did not receive an intervention. Each unit increase in Edmonton Frailty Score raises the odds of being in DRG with MCC by 1.24 (95% CI 1.04-1.48, P 0.017). Similar trends were seen for OR time and LOS. Reimbursement showed incremental increase from $49.5K to $56K to $70K across DRG categories. CONCLUSIONS:Patients with elevated ISSG-AO scores are more likely to be categorized into higher DRGs, experience extended lengths of stay and generate greater healthcare expenditures. The ISSG-AO SDCCS predicts DRG thereby helping standardize complication reporting.

PURPOSE/OBJECTIVE:To compare the impact of lumbar lordosis correction achieved by cephalad versus caudal distribution on radiographic alignment and surgical outcomes among adult spinal deformity (ASD) patients. METHODS:Patients who underwent ASD surgery with uppermost instrumented vertebrae (UIV) at or above L1, had preoperative pelvic incidence-lumbar lordosis (PI-LL) > 10°, and had full-body radiographs available were included. Eligible patients were categorized by the focus of lordosis correction: caudal (L4-S1 lordosis between 35 and 45°) and cephalad lordosis-based correction. Patient demographics, preoperative and 2 years spinopelvic alignment and PROMs, and 2 years postoperative surgical complications were compared. RESULTS:In total, 187 (111 caudal and 76 cephalad) patients were included, with mean age of 66.2 years, 78.6% female, and mean frailty score of 3.6. Caudally-restored patients often had an upper thoracic UIV, sacrum/ilium LIV, longer length of fusion, and no lateral lumbar interbody fusion (LLIF) while cephaladly-restored patients had two or more LLIFs above L4 (p < 0.001). Preoperatively, there were no significant differences in radiographic alignment and PROMs between the two groups (p > 0.02). Two years postoperatively, caudally-restored patients had higher L1-S1 LL (p = 0.015) and L4-S1 LL (p < 0.001), and lower PI-LL (p = 0.039) and SVA (p = 0.001). In addition, they had higher SRS-22 activity (p = 0.045), pain (p = 0.047), appearance (p = 0.046), and total (p = 0.016) scores. Finally, they had lower rates of sensory deficits (p < 0.001), motor deficits (p = 0.003), implant failure (p = 0.092), and reoperation (p = 0.020). CONCLUSION/CONCLUSIONS:Caudal lordosis-based correction of spinal deformity patients was associated with higher PROMs and lower rates of neurologic deficits, implant failure, and revisions at 2 years. These findings, while subject to unmeasured confounding, indicate that great caution should be taken when considering cephalad-based correction of ASD.

BACKGROUND:Pelvic tilt (PT) has been a parameter of interest in biomechanics of spinal deformity for decades. It remains unclear how patients achieve different values of PT pre- and postoperatively. RESEARCH QUESTION/OBJECTIVE:This study aimed at assessing the relative contribution of hip extension, knee flexion and ankle extension to PT, factoring malalignment and hip osteoarthritis (OA). METHODS:This retrospective study included Adult Spinal Deformity (ASD) patients with preoperative full-body radiographs from a multicenter database, with a sub-analysis of patients with complete 1-year follow-up (1yFU). Age and PI-adjusted normative PT (NormPT) and offset from norm (OffPT) were calculated, as for sacro-femoral angle (SFA), knee flexion angle (KA) and ankle angle (AA). Multivariate linear regression models controlling for age, frailty, severe hip OA, pelvic incidence (PI), SFA, and KA were used to predict PT at baseline, and offset from NormPT. Another model was generated to predict PT change. RESULTS:600 patients at baseline and 336 with 1yFU were included. Mean age was 61 ± 15, 70.2 % were females and 40 % were revision cases. At baseline, regression analysis revealed that 0.9° increase in hip extension (SFA) and a 0.6° increase in knee flexion (KA) amounted to 1° increase in PT. Knee and ankle contribution to PT significantly increased for while hip extension decreased as TPA augmented (p < 0.001). Patients with low deformity compensated with hip extension, while knee flexion was the largest contributor of PT in high deformity patients: 70.7 % (44.7 - 111.9). Median contribution of knee flexion to PT was larger for patients who presented hip OA. SIGNIFICANCE/CONCLUSIONS:This study demonstrated that PT is a phenomenon driven by extension of the hips and flexion of the knees and proposed values to predict PT from those two compensatory mechanisms. Magnitude of spinal deformity and hip OA alters the magnitude of SFA/KA contribution to PT.

BACKGROUND:Early-term complications may not predict long-term success after adult cervical deformity (ACD) correction. OBJECTIVE:Evaluate whether optimal realignment results in similar rates of perioperative complications but achieves longer-term cost-utility. STUDY DESIGN/METHODS:Retrospective cohort study. METHODS:ACD patients with 2-year data included. Outcomes: distal junctional failure (DJF), good clinical outcome (GCO):[Meeting 2 of 3: (1) NDI>20 or meeting MCID, (2) mJOA≥14, (3)NRS-Neck improved≥2]. Ideal Outcome defined as GCO without DJF or reoperation. Patient groups were stratified by correction to 'Optimal radiographic outcome', defined by cSVA 9 (<40 mm) AND TS-CL (<15 deg) upon correction. Cost calculated by CMS.com definitions, and cost-per-QALY was calculated by converting NDI to SF-6D. Multivariable analysis controlling for age, baseline T1-slope, cSVA, disability, and frailty, was used to assess complication rates, clinical outcomes, and cost-utility based on meeting optimal radiographic outcome. RESULTS:One hundred forty-six patients included: 52 optimal radiographic realignment (O) and 94 not optimal (NO). NO group presented with higher cSVA and T1-slope. Adjusted analysis showed O group suffered similar 90-day complications (P>0.8), but less DJK, DJF (0% vs. 18%; P<0.001) and reoperations (18% vs. 35%; P=0.02). Patients meeting optimal radiographic criteria more often met Ideal outcome [odds ratio: 2.2, (1.1-4.8); P=0.03]. Despite no differences in overall cost, O group saw greater clinical improvement, translating to a better cost-utility [mean difference: $91,000, ($49,000-$132,000); P<0.001]. CONCLUSION/CONCLUSIONS:Despite similar perioperative courses, patients optimally realigned experienced less junctional failure, leading to better cost-utility compared with those sub-optimally realigned. Perioperative complication risk should not necessarily preclude optimal surgical intervention, and policy efforts might better focus on long-term outcome measures in adult cervical deformity surgery. LEVEL OF EVIDENCE/METHODS:Level III.

STUDY DESIGN/METHODS:Retrospective cohort study. OBJECTIVE:To examine the degree of overlap between disability, multimorbidity, and frailty in a cohort of ASD patients. SUMMARY OF BACKGROUND DATA/BACKGROUND:Frailty is a popular topic in spine research, as it is a reported risk factor for poor outcomes. Disability, multimorbidity, and frailty can coexist, sometimes causing or exacerbating one another. It is important to distinguish these conditions for perioperative optimization and to guide research initiatives. METHODS:A multicenter registry of ASD patients was queried for baseline data regarding frailty, as measured by the Edmonton Frail Scale, disability, as measured by the Oswestry Disability Index, and multimorbidity, as measured by the Charlson Comorbidity Index. The relationships between these measures and both chronological and biological age (PhenoAge) were explored. Exploratory factor analysis (EFA) examined areas of overlap between these diagnoses. RESULTS:There were 861 patients contributing data, mostly female (68%), most undergoing primary surgery at a median age of 66 years (Interquartile Range (55.1-71.6), with 6% classified as "Frail." Chronological and PhenoAge showed weak to moderate associations with disability and frailty, though PhenoAge was stronger. There was no evidence of distinct clusters, rather a continuity of condition severity. EFA found overlap between subjective and objective measures of disability, function, and frailty. CONCLUSIONS:Frailty was rare (6%) in this multicenter cohort of patients. Conflation of disability and frailty is a real risk due to overlap in measures of both conditions. Disability and frailty do not form discrete categories but rather exist along a continuum, underscoring the need to abandon categorical labels in favor of continuous measures for both clinical assessment and research settings.

OBJECTIVE:The aim of this retrospective study was to investigate the relationship between postoperative Roussouly sagittal profile changes and patient outcomes. METHODS:From a prospectively collected, single-center database, the authors reviewed the records of patients with adult spinal deformity (ASD) who had clinical and radiographic data from baseline to 2 years after surgery. The patients were stratified by their Roussouly curve type (current sacral slope-based and "theoretical" pelvic incidence-based types). Means comparison tests (ANOVA and chi-square) were used to assess differences among Roussouly groups. Backstep logistic regression analyses were used to analyze associations between Roussouly sagittal profile changes and patient outcomes, including minimum clinically important differences (MCIDs) in functional metrics. RESULTS:Five hundred twenty-five patients, 79% of whom were female, were included in this study. The mean age of the cohort was 60.8 ± 14.1 years, BMI was 27.2 ± 5.5 kg/m2, and Charlson Comorbidity Index score was 1.72 ± 1.68. According to the Roussouly classification, 8.3% of patients had a Roussouly type 1 (R1) curve, 53.6% type 2 (R2), 26.3% type 3 (R3), and 11.9% type 4 (R4). Overall, 39% of patients had a changed Roussouly shape postoperatively: 59% had R1, 58.5% R2, 48.1% R3, and 26.7% R4 (p < 0.001). Forty-eight percent of patients matched the theoretical Roussouly type postoperatively (41% R1, 41.5% R2, 51.9% R3, and 73.3% R4, p < 0.001). When controlling for baseline clinical and radiographic differences, the Roussouly type changes associated with a higher risk of proximal junctional kyphosis or proximal junctional failure were as follows: R1 to R2 (OR 2.5, 95% CI 1.1-5.6, p = 0.024), R2 to R4 (OR 2.8, 95% CI 1.1-7.7, p = 0.039), and R3 to R4 (OR 2.3, 95% CI 1.1-4.9, p = 0.033). R4 to R3 switches had the highest mechanical complication risks (OR 3.4, 95% CI 1.2-9.4, p = 0.016). R1 to R2 changes had the highest rate of attaining an MCID in the Oswestry Disability Index at 6 weeks (23.5%, p = 0.004). Roussouly type changes were not associated with differences in the MCID on the refined 22-item Scoliosis Research Society patient outcome questionnaire (SRS-22r) up to 2 years after surgery. CONCLUSIONS:While a significant portion of patients matched their postoperative theoretical Roussouly type, many of those matched at baseline were prone to become unmatched postoperatively. Postoperative Roussouly shape changes influence patient outcomes and should be accounted for when planning ASD surgery.

STUDY DESIGN/METHODS:Retrospective Multi-Center Study. OBJECTIVE:To investigate how advances in spine realignment have impacted lumbar segmental alignment. SUMMARY OF BACKGROUND DATA/BACKGROUND:The understanding of spine alignment and Adult Spinal Deformity (ASD) management continues to advance. It remains unknown how these advances have influenced lumbar segmental alignment changes in the setting of surgical correction. METHODS:Patients undergoing primary thoracolumbar fusion for ASD were stratified based on enrolment in two distinct multicenter registries; forming an 'Early' (2008-2017) and a 'Late cohort' (2018-present). Patients were further stratified based on pelvic incidence (PI) and Roussouly type. Segmental alignment was determined based on published values of asymptomatic individuals. Pelvic incidence-based alignment and Roussouly-based alignment were determined in alignment with previously published normative values. Means comparisons tests and multivariate analyses compared segmental & regional parameters between groups. RESULTS:1240 patients included (622 EARLY, 618 LATE). The mean age was 61.4±14.5 years, body mass index (BMI) was 28.0±5.8 kg/m2, and Charlson comorbidity index (CCI) was 1.55±1.70. 70.2% of patients were female gender. LATE consistently displayed better L5-S1 alignment across all PI and Roussouly types (P=0.001) However, EARLY demonstrated better L4-5 alignment (P=0.001). Improved alignment in L5-S1, L4-5 and L3-4 was associated with achieving minimum clinically important difference in ODI scores and decreased risk of mechanical complications. Both cohorts demonstrated low rates of matching L4-S1 regional and overall lumbar lordosis L1-S1 alignment, with no differences between both groups. By lordosis distribution index, both groups had predominantly hyperlordotic maldistribution postop, but LATE had more 'Aligned' patients (15.9 vs. 11%, P<0.001). CONCLUSIONS:Over the past 15 years, surgeons appear to be better at restoring ideal lumbar segmental sagittal alignment in ASD patients. However, idealized correction does not appear to be uniform across all lumbar segments, representing an opportunity for further improvement. LEVEL OF EVIDENCE/METHODS:III.

STUDY DESIGN/METHODS:Retrospective cohort study. OBJECTIVE:Due to proximity of the surgical site to important respiratory structures, patients may undergo delayed extubation after adult cervical deformity (ACD) surgery to manage postoperative airway edema/obstruction. Herein, we evaluate relevant relationships with delayed extubation. SUMMARY OF BACKGROUND DATA/BACKGROUND:Delayed extubation is an underreported perioperative occurrence, with only a few studies conducting case-by-case reviews of prolonged intubation. METHODS:Operative ACD patients with baseline (BL) were grouped based on whether they experienced delayed extubation (DE), or leaving the OR while still intubated, versus those who were extubated successfully in the OR (non-DE). Means comparison and regression analyses identified predictors of delayed extubation and associations with peri-operative complications and outcomes. RESULTS:82 patients met inclusion criteria (mean age 62.4±13.0 y, 52.4% female, Edmonton frailty score: 5.10±2.97, ACFI score: 0.30±0.16, CCI: 1.41±1.73). 14 patients left the OR intubated, and 1(1.2%) required reintubation. DE cohort demonstrated greater Edmonton frailty scores (P=0.017) and smoking histories (P=0.031). Intraoperatively, there was a significant difference EBL (P=0.021) and rate of transfusions (DE: 27.3% v non-DE: 4.8%, P=0.12). Upper instrumented vertebra (UIV) was not associated with DE, while lower LIV increased the likelihood of DE (OR 1.1, P=0.029). Post-operatively, as expected, there was a significant difference in rate of SICU admissions (DE: 90.9% v. non-DE: 49.2%, P=0.01), although no significant differences in LOS. Greater cSVA and MGS correction from baseline was associated with increased likelihood of delayed extubation (OR 1.1, CI 95% 1.05-1.17, P<.001; OR 1.14, CI 95% 1.05-1.24, P=0.003). Furthermore, delayed extubation was a significant predictor of increased VR-Physical Component Scores (P=0.013) at 6W, and DE cohort demonstrated significantly higher VR-PCS and VR-MCS Scores at 6W (P=0.01, both). CONCLUSIONS:Baseline frailty and larger radiographic correction can be associated with delayed extubation, which can impact quality of life perioperatively. Considerations like minimizing intraoperative blood loss and degree of correction could minimize delayed extubation.

STUDY DESIGN/METHODS:Prospective, multi-center analysis. OBJECTIVE:Evaluate the impact that self-image has upon operative vs. nonoperative treatment choice for adult spine deformity (ASD) patients, and evaluate the association of post-treatment self-image with treatment satisfaction. SUMMARY OF BACKGROUND DATA/BACKGROUND:ASD outcomes traditionally focus upon pain and physical function. Self-image is an important outcome measure for pediatric spine deformity. Little data exists regarding the impact self-image has upon ASD treatment choice and outcomes. METHODS:Factor analysis and decision tree modeling was performed upon ASD patients prospectively enrolled into a multi-center study from 2009-2020. Data elements from physical examination, demographics, spinal alignment, and individual questions from administered PROMs including SRS-22r, ODI, SF-36, and NRS back and leg pain were evaluated for variables that correlated most with (1) patients electing for operative vs. nonoperative treatment and (2) treatment satisfaction at minimum 2-year follow-up. RESULTS:Evaluation of 735 ASD patients demonstrated operatively treated patients (OP; n=548) were older (58.0±15.3 vs. 52.4±16.0 years; P<0.0001), had similar scoliosis (44.9±20.1° vs. 45.5±16.1°; P=0.5555) but worse sagittal malalignment than nonoperatively treated patients (NON; n=187; P<0.0001, respectively). Baseline PROMs were worse for OP vs. NON (P<0.0001). Gradient-boosted decision trees, factor analysis, and logistic regression of demographic, physical examination, radiographic, and PROM variables associated with treatment choice demonstrated self-image (odds ratio=4.5; 95% CI=3.4-6.0; P<0.0001) had the greatest correlation for patients choosing operative treatment. At minimum 2-year follow-up self-image demonstrated the greatest health domain improvement for OP and self-image improvement correlated most with post-treatment satisfaction, while NON demonstrated deterioration of self-image and reported poor treatment satisfaction. CONCLUSION/CONCLUSIONS:Multi-variable evaluation of 735 operative and nonoperative treated ASD patients demonstrated baseline self-image strongly correlated with ASD patients pursuing surgical treatment and postoperative treatment satisfaction. Patient self-image is a critical measure that must be assessed in ASD.