Faculty Bibliography

STUDY DESIGN/UNASSIGNED:Comparative cohort study. OBJECTIVE/UNASSIGNED:Factors that influence the lower instrumented vertebra (LIV) selection in adult cervical deformity (ACD) are less reported, and outcomes in the cervicothoracic junction (CTJ) and proximal thoracic (PT) spine are unclear. METHODS/UNASSIGNED:A prospective ACD database was analyzed using the following inclusion criteria: LIV between C7 and T5, upper instrumented vertebra at C2, and at least a 1-year follow-up. Patients were divided into CTJ (LIV C7-T2) and PT groups (LIV T3-T5) based on LIV levels. Demographics, operative details, radiographic parameters, and the health-related quality of life (HRQOL) scores were compared. RESULTS/UNASSIGNED:= 0.001). Complications and reoperations were comparable. The HRQOL scores were not different preoperatively and at 1-year follow-up. CONCLUSIONS/UNASSIGNED:The selection of PT LIV in cervical deformities was more common in patients with larger baseline deformities, who were more likely to undergo pedicle-subtraction osteotomy. Despite this, the complications and HRQOL outcomes were comparable at 1-year follow-up.

BACKGROUND:Frailty severity may be an important determinant for impaired recovery after cervical spine deformity (CD) corrective surgery. OBJECTIVE:To evaluate postop clinical recovery among CD patients between frailty states undergoing primary procedures. METHODS:Patients >18 yr old undergoing surgery for CD with health-related quality of life (HRQL) data at baseline, 3-mo, and 1-yr postoperative were identified. Patients were stratified by the modified CD frailty index scale from 0 to 1 (no frailty [NF] <0.3, mild/severe fraily [F] >0.3). Patients in NF and F groups were propensity score matched for TS-CL (T1 slope [TS] minus angle between the C2 inferior end plate and the C7 inferior end plate [CL]) to control for baseline deformity. Area under the curve was calculated for follow-up time intervals determining overall normalized, time-adjusted HRQL outcomes; Integrated Health State (IHS) was compared between NF and F groups. RESULTS:A total of 106 CD patients were included (61.7 yr, 66% F, 27.7 kg/m2)-by frailty group: 52.8% NF, 47.2% F. After propensity score matching for TS-CL (mean: 38.1°), 38 patients remained in each of the NF and F groups. IHS-adjusted HRQL outcomes from baseline to 1 yr showed a significant difference in Euro-Qol 5 Dimension scores (NF: 1.02, F: 1.07, P = .016). No significant differences were found in the IHS Neck Disability Index (NDI) and modified Japanese Orthopedic Association between frailty groups (P > .05). F patients had more postop major complications (31.3%) compared to the NF (8.9%), P = .004, though DJK occurrence and reoperation between the groups was not significant. CONCLUSION/CONCLUSIONS:While all groups exhibited improved postop disability and pain scores, frail patients experienced greater amount of improvement in overall health state compared to baseline disability. This signifies that with frailty severity, patients have more room for improvement postop compared to baseline quality of life.

STUDY DESIGN/METHODS:Retrospective review of a prospective multicenter cervical deformity database OBJECTIVE.: To examine the differences in sagittal alignment correction between three positioning methods in cervical spinal deformity surgery (CD). SUMMARY OF BACKGROUND DATA/BACKGROUND:Surgical correction for CD is technically demanding and various techniques are utilized to achieve sagittal alignment objectives. The effect of different patient positioning techniques on sagittal alignment correction following CD remains unknown. METHODS:Patients with sagittal deformity who underwent a posterior approach (with and without anterior approach) with an upper instrumented vertebra of C6 or above. Patients with Grade 5, 6 or 7 osteotomies were excluded. Positioning groups were Mayfield skull clamp, bivector traction, and halo ring. Pre-operative lower surgical sagittal curve (C2-C7), C2-C7 sagittal vertical axis (cSVA), cervical scoliosis, T1 slope minus cervical lordosis (TS-CL), T1 Slope (T1S), chin-brow vertebral angle (CBVA), C2-T3 curve, and C2-T3 SVA was assessed and compared to post-operative radiographs. Segmental changes were analyzed using the Fergusson method. RESULTS:80 patients (58% female) with a mean age was 60.6 ± 10.5 years (range 31-83) were included. The mean post-operative C2-C7 lordosis was 7.8°±14 and C2-C7 SVA was 34.1mm ± 15. There were overall significant changes in cervical alignment across the entire cohort, with improvements in T1 slope (p < 0.001), C2-C7 (p < 0.001), TS-CL (p < 0.001), and cSVA (p = 0.006). There was no difference post-operatively of any radiographic parameter between positioning groups (p > 0.05). The majority of segmental lordotic correction was achieved at C4-5-6 (Mean 6.9°±11). Additionally, patients who had bivector traction applied had had significantly more segmental correction at C7-T1-T2 compared to Mayfield and halo traction (4.2° vs. 0.3° vs. -1.7° respectively, p < 0.027). CONCLUSION/CONCLUSIONS:Post-operative cervical sagittal correction or alignment was not affected by patient position. The majority of segmental correction occurred at C4-5-6 across all positioning methods, while bivector traction had the largest corrective ability at the cervicothoracic junction. LEVEL OF EVIDENCE/METHODS:4.

STUDY DESIGN/METHODS:Retrospective review of a prospective database. OBJECTIVE:Identify demographic, surgical, and radiographic factors that predict superior recovery kinetics following CD corrective surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:Analyses of cervical deformity (CD) corrective surgery use area-under-the-curve (AUC) to assess health-related quality of life (HRQL) metrics throughout recovery. METHODS:Outcome Measures: Baseline (BL) to 1-Year (1Y) HRQL (Neck Disability Index [NDI]). CD criteria: C2-7 Cobb angle>10°, coronal Cobb angle>10°, cSVA>4 cm TS-CL>10°, or CBVA>25°. AUC normalization divided BL and postoperative outcomes by BL. Normalized scores(y-axis) were plotted against follow-up(x-axis). AUC was calculated and divided by cumulative follow-up length to determine overall, time-adjusted recovery (Integrated Health State [IHS]). IHS NDI was stratified by quartile, uppermost 25% being 'Superior' Recovery Kinetics (SRK) vs. 'Normal' Recovery Kinetics (NRK). BL demographic, clinical, and surgical information predicted SRK using generalized linear modeling. RESULTS:98 patients included (62 ± 10yrs, 28 ± 6 kg/m2, 65%F, CCI:0.95), 6% smokers, 31% smoking history. Surgical approach: combined (33%), posterior (49%), anterior (18%). Posterior levels fused: 8.7, anterior: 3.6, EBL: 915.9ccs, operative time: 495 min. Ames BL classification: cSVA (53.2% minor deformity, 46.8% moderate), TS-CL (9.8% minor, 4.3% moderate, 85.9% marked), horizontal gaze (27.4% minor, 46.6% moderate, 26% marked). Relative to BL NDI (Mean: 47), normalized NDI decreased at 3-months (0.9 ± 0.5, p = 0.260) and 1Y (0.78 ± 0.41, p < 0.001). NDI IHS correlated with age (p = 0.011), gender (p = 0.042), anterior approach (p = 0.042), posterior approach(p = 0.042). Greater BL PT (SRK:25.6°, NRK:17°, p = 0.002), PI-LL (SRK:8.4°, NRK:-2.8°, p = 0.009), and anterior approach (SRK:34.8%, NRK:13.3%; p = 0.020) correlated with SRK. 69.4% met MCID for NDI(<Δ-15) and 63.3% met SCB for NDI(<Δ-10); 100% of SRK met both MCID and SCB. The predictive model for SRK included(AUC = 88.1%): BL VAS EQ5D(OR 0.96, CI:0.92-0.99), BL swallow sleep score(OR:1.04, CI:1.01-1.06), BL PT(OR:1.12, CI:1.03-1.22), BL mJOA (OR:1.5, CI:1.07-2.16), BL T4-T12, BL T10-L2, BL T12-S1 and BL L1-S1. CONCLUSIONS:Superior recovery kinetics following cervical deformity surgery was predicted with high accuracy using baseline patient reported (VAS EQ5D, swallow sleep, mJOA) and radiographic factors (PT, TK, T10-L2, T12-S1, L1-S1). Awareness of these factors can improve decision-making and reduce postoperative neck disability.Level of Evidence: 3.

STUDY DESIGN/UNASSIGNED:Retrospective study. OBJECTIVES/UNASSIGNED:Our goal was to evaluate the rate of rod fracture and persistent pseudarthrosis in cohorts of patients treated with a dual rod or multiple-rod construct in revision surgery for pseudarthrosis. METHODS/UNASSIGNED:A dual rod construct was used in 23 patients, and a multiple rod construct in 24 patients, spanning the pseudarthrosis level. Two-year fusion grading, and rates of pseudarthrosis and implant failure, were assessed. RESULTS/UNASSIGNED:There were no differences in patient or surgical characteristics between the groups: (2- rod construct: Age 60 ± 14, Levels 10 ± 5, 3-column osteotomy:17%; multiple-rod construct: Age: 62 ± 11, Levels 9 ± 4, 3-column osteotomy:30%). Patients in the multiple rod construct were transfused a greater volume of packed red blood cells (pRBCs) intraoperatively (2.6 ± 2.9 vs. 1.1 ± 1.5 U, p < 0.0001). At 2 year follow up there was no difference in fusion grades at the previous level of pseudarthrosis, the rate of rod fracture or pseudarthrosis between the 2 groups, or rate of reoperation for pseudarthrosis, rod fracture, wound infection, hardware prominence, or PJK/PJF. CONCLUSIONS/UNASSIGNED:Our data demonstrate no difference in fusion grade, or rates of rod fracture and revision at 2 years, after utilizing a dual rod versus multiple rod construct in revision surgery for pseudarthrosis. The low complication rates seen with either configuration warrant further investigation of the optimal instrumentation configuration.

OBJECTIVE:Patients with nonoperative (N-Op) adult spinal deformity (ASD) have inferior long-term spinopelvic alignment and clinical outcomes. Predictors of lower quality-of-life measures in N-Op populations have yet to be sufficiently investigated. The aim of this study was to identify patient-related factors and radiographic parameters associated with inferior health-related quality-of-life (HRQOL) scores in N-Op ASD patients. METHODS:N-Op ASD patients with complete radiographic and outcome data at baseline and 2 years were included. N-Op patients and operative (Op) patients were propensity score matched for baseline disability and deformity. Patient-related factors and radiographic alignment parameters (pelvic tilt [PT], sagittal vertical axis [SVA], pelvic incidence [PI]-lumbar lordosis [LL] mismatch, mismatch between cervical lordosis and T1 segment slope [TS-CL], cervical-thoracic pelvic angle [PA], and others) at baseline and 2 years were analyzed as predictors for moderate to severe 2-year Oswestry Disability Index (ODI > 20) and failing to meet the minimal clinically importance difference (MCID) for 2-year Scoliosis Research Society Outcomes Questionnaire (SRS) scores (< 0.4 increase from baseline). Conditional inference decision trees identified predictors of each HRQOL measure and established cutoffs at which factors have a global effect. Random forest analysis (RFA) generated 5000 conditional inference trees to compute a variable importance table for top predictors of inferior HRQOL. Statistical significance was set at p < 0.05. RESULTS:Six hundred sixty-two patients with ASD (331 Op patients and 331 N-Op patients) with complete radiographic and HRQOL data at their 2-year follow-up were included. There were no differences in demographics, ODI, and Schwab deformity modifiers between groups at baseline (all p > 0.05). N-Op patients had higher 2-year ODI scores (27.9 vs 20.3, p < 0.001), higher rates of moderate to severe disability (29.3% vs 22.4%, p = 0.05), lower SRS total scores (3.47 vs 3.91, p < 0.001), and higher rates of failure to reach SRS MCID (35.3% vs 15.7%, p < 0.001) than Op patients at 2 years. RFA ranked the top overall predictors for moderate to severe ODI at 2 years for N-Op patients as follows: 1) frailty index > 2.8, 2) BMI > 35 kg/m2, T4PA > 28°, and 4) Charlson Comorbidity Index > 1. Top radiographic predictors were T4PA > 28° and C2-S1 SVA > 93 mm. RFA also ranked the top overall predictors for failure to reach 2-year SRS MCID for N-Op patients, as follows: 1) T12-S1 lordosis > 53°, 2) cervical SVA (cSVA) > 28 mm, 3) C2-S1 angle > 14.5°, 4) TS-CL > 12°, and 5) PT > 23°. The top radiographic predictors were T12-S1 Cobb angle, cSVA, C2-S1 angle, and TS-CL. CONCLUSIONS:When controlling for baseline deformity in N-Op versus Op patients, subsequent deterioration in frailty, BMI, and radiographic progression over a 2-year follow-up were found to drive suboptimal patient-reported outcome measures in N-Op cohorts as measured by validated ODI and SRS clinical instruments.

STUDY DESIGN:Retrospective review of prospective multicenter database. OBJECTIVE:The aim of this study was to investigate how preoperative mental status affects preoperative and postoperative disability and health scores in adult spinal deformity (ASD) patients. SUMMARY OF BACKGROUND DATA:The relationship between health-related quality of life (HRQOL) and depression has previously been documented. However, the influence of depression on clinical outcomes among ASD patients is not well understood. METHODS:ASD patients with minimum 2-year follow-up were stratified based on preoperative mental health measured by Short Form 36 (SF-36) mental component score (MCS). Patients with MCS in the 25th and 75th percentile of the cohort were designated as having low and high MCS, respectively. After matching by preoperative demographics and deformity, pre- and post-HRQOL were compared between the two groups. Further analysis was performed to identify individualized questions on the SF-36 that could potentially screen for patients with low MCS. RESULTS:Five hundred thirteen patients were assessed (58.4 years' old, 79% women, mean MCS 45.5). Thresholds for low and high MCS cohorts were 35.0 and 57.3, respectively. After matching by preoperative alignment, low MCS patients had worse Oswestry Disability Index (ODI) (52.3 ± 17.0 vs. 35.7 ± 14.6, P < 0.001) and Scoliosis Research Society-22R scores for all domains (all P < 0.001) compared to high MCS patients. Similar results were maintained at 2-year postop, with low MCS patients having a worse ODI (35.2 ± 20.2 vs. 19.7 ± 18.6, P < 0.001) and MCS (42.4 ± 13.5 vs. 58.6 ± 7.1, P < 0.001). Despite similar preoperative Physical Component Score (PCS), low MCS patients were less likely to reach MCID for PCS (46.1% vs. 70.6%, P < 0.01) and had a lower satisfaction at 2-year follow-up (3.88 ± 1.07 vs. 4.39 ± 0.94, P < 0.001). Questions 5a, 9d, and 9f on the SF-36 were found to be independent predictors of low MCS. CONCLUSION:ASD patients with low MCS are more likely to experience functional limitations before and after surgery and are less likely to be satisfied postoperatively, even when similar clinical goals are achieved. Incorporating psychological factors may assist in decision making.Level of Evidence: 3.

BACKGROUND:Spinal surgery is associated with an inherently elevated risk profile, and thus far there has been limited discussion about how these outpatient spine patients are benefiting from these same-day procedures against other typical outpatient orthopedic surgeries. METHODS:Orthopedic patients who received either inpatient or outpatient surgery were isolated in the American College of Surgeons National Surgical Quality of Improvement Program (2005-2016). Patients were stratified by type of orthopedic surgery received (spine, knee, ankle, shoulder, or hip). Mean comparisons and chi-squared tests assessed basic demographics. Perioperative complications were analyzed via regression analyses in regard to their principal inpatient or outpatient orthopedic surgery received. RESULTS:< .05) with complications decreasing for IN and OUT patients by 2016. CONCLUSIONS:Over the past decade, spine surgery has decreased in complications for IN and OUT procedures along with IN/OUT knee, ankle, hip, and shoulder procedures, reflecting greater tolerance for risk in an outpatient setting. LEVEL OF EVIDENCE/METHODS:3. CLINICAL RELEVANCE/CONCLUSIONS:Despite the increase in riskier spine procedures, complications have decreased over the years. Surgeons should aim to continue to decrease inpatient spine complications to the level of other orthopedic surgeries.

Background/UNASSIGNED:Adolescent idiopathic scoliosis (AIS) is a common cause of spinal deformity in adolescents. AIS can be associated with certain intraspinal anomalies such as syringomyelia (SM). This study assessed the rate o f SM in AIS patients and compared trends in surgical approach and postoperative outcomes in AIS patients with and without SM. Methods/UNASSIGNED:-tests and Chi-squared tests for categorical and discrete variables, respectively. Results/UNASSIGNED:< 0.001). Conclusions/UNASSIGNED:These results indicate that patients concordant with AIS and SM may be treated more cautiously (lower invasiveness score and less fusions) than those without SM.

Purpose/UNASSIGNED:The aim is to investigate the relationship between cervical parameters and the modified Japanese Orthopedic Association scale (mJOA). Materials and Methods/UNASSIGNED:> 0.05), Pearson correlations were run for radiographic parameters and mJOA. For significant correlations, logistic regressions were performed to determine a threshold of radiographic measures for which the correlation with mJOA scores was most significant. mJOA score of 14 and <12 reported cut-off values for moderate (M) and severe (S) disability. New modifiers were compared to an existing classification using Spearman's rho and logistic regression analyses to predict outcomes up to 2 years. Results/UNASSIGNED:= 0.002). Compared to existing Ames- International Spine Study Group classification, the novel thresholds demonstrated significant predictive value for reoperation and mortality up to 2 years. Conclusions/UNASSIGNED:Collectively, these radiographic values can be utilized in refining existing classifications and developing collective understanding of severity and surgical targets in corrective surgery for adult CD.