Faculty Bibliography

BACKGROUND CONTEXT: T1 slope (T1S) and C2 slope (C2S) are important radiographic parameters for cervical deformity (CD) patients, with higher T1S and C2S both corresponding to worse cervical alignment. In addition, prior research has shown higher T1S is associated with poor global sagittal alignment. These two parameters can be used to group patients into distinct spinal deformities with low T1S-high C2S (LTHC) representing CD only and high T1S-high C2S (HTHC) representing global deformity without cervical compensation. PURPOSE: Examine differences in surgical and radiographic outcomes in surgical CD patients with global deformity (HTHC) vs CD only (LTHC). STUDY DESIGN/SETTING: Retrospective review of a prospective multicenter database. PATIENT SAMPLE: Surgical CD patients with high C2S and minimum 1-year follow-up. OUTCOME MEASURES: Surgical characteristics, Postoperative complications, Neck Disability Index (NDI), and radiographic parameters, such as thoracic kyphosis (TK), T1 pelvic angle (TPA), and C7 sagittal vertical axis (cSVA).
METHOD(S): A prospective multicenter database of operative CD patients was analyzed. Inclusion criteria was patients with at least 1 year of follow-up and preoperative high C2S. High C2S (>30degree) was defined by 1 SD above the previously published mean for asymptomatic subjects with an overall kyphotic cervical morphotype. Patients were categorized as LTHC if T1S <= 30degree and HTHC if T1S > 30degree. Severe Distal Junctional Kyphosis (DJK) was defined as DJK angle change >20degree. Statistical analysis included independent samples t-test and chi-square analysis with significance set to p<0.05.
RESULT(S): Ninety-two patients met inclusion criteria (61 HTHC, 31 LTHC). HTHC had greater preoperative TK (-72.86 vs -46.59degree), TPA (18.01 vs 10.56degree), and cSVA (57.96 vs 38.77mm), all p<.010. At 1-year postop, HTHC had higher TK (-69.40 vs -59.67degree) and cSVA (48.95 vs 39.36mm), both p<.05; though there were greater improvements in TK and cSVA for HTHC, while TK worsened for LTHC. HTHC had more posterior levels fused (10.28 vs 6.65), fewer anterior levels fused (1.16 vs 2.23), and more circumferential fusions (66.7% vs 38.7%), all p<.05. Lower instrumented vertebrae (LIV) was more caudal in HTHC (13.65 vs 9.55, p<.001). Both groups had similar baseline Neck Disability Index (NDI) scores (49.55 vs 49.10), but HTHC had less NDI improvement at 1 year (-6.75 vs -15.47, p=.023). There were no significant differences in rates of postop minor (18.0% vs 12.9%, p= 0.529) or major (11.5% vs 9.7%, p=0.793) complications, severe DJK (1.6% vs 6.5%, p= 0.219), or reoperation (4.9% vs 3.2%, p=0.707).
CONCLUSION(S): HTHC have worse global sagittal alignment than LTHC, both preoperatively and at 1 year postoperatively. They require more aggressive procedures with more levels fused, lower LIV, and more circumferential fusions, but have no differences in postop complications. HTHC had smaller 1 year HRQL improvements, likely due to their continued worse global alignment postoperatively. The relationship of T1S and C2S is important in understanding the burden of global spinal deformity in operative cervical deformity patients. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Since circumferential adult spinal deformity (ASD) surgery can lead to high surgical burden for the patient, surgeons may elect to stage these procedures during the same hospitalization. As a result, there is a trend toward planning same-hospitalization staged ASD surgeries by performing an anterior lumbar interbody fusion (ALIF) prior to a subsequent staged posterior fusion. PURPOSE: The aim of this study was to determine optimal timing for staging (early vs delayed) thoracolumbar ASD surgery within the same hospitalization. STUDY DESIGN/SETTING: Retrospective review of a multicenter database. PATIENT SAMPLE: A total of 158 surgical ASD patients undergoing anterior and staged posterior spinal fusion >=5 levels. OUTCOME MEASURES: Our outcome measures were 90-day complication rates, postoperative alignment, and 2-year ODI.
METHOD(S): Using a prospective, multicenter database, we identified 158 surgical ASD patients undergoing first an anterior surgery followed by a staged posterior spinal fusion >=5 levels during the same hospitalization. Stratum-specific likelihood ratio (SSLR) analysis was performed to calculate a cutoff point beyond which 90-day complications were increased. The cutoff generated through SSLR were confirmed with multivariable logistic regression analysis controlling for age, gender, levels fused for each stage, preoperative alignment, three-column osteotomy, and Charlson Comorbidity Index. The outcome measures were 90-day complication rates, postoperative alignment, and 2-year ODI. Multivariable analyses were performed with logistic, Poisson and linear regressions where appropriate.
RESULT(S): Utilization of staged procedures increased 4x from 2008-2019, and the mean staging interval was 3 days (range 1-8). On SSLR analysis, patients were divided into two staging categories based on complication risk: early (<6 days, range 1-5, N=139) versus delayed (>= 6 day, range 6-8, N=19). On bivariate analysis, the delayed group had higher 90-day complication rates (68.4% vs 32.4%, p=0.002) and longer operative times (638 min vs 739 min, p=0.020) relative to the early group. Adjusting for covariates on multivariable analysis, patients with delayed staging had significantly greater odds of 90-day complications (OR=7.57, p=0.006), and longer total operative time (beta=119, p=0.035). With respect to specific complications, delayed staging carries increased odds of infection compared to early staging (OR=11.8 p=0.031). There were no significant differences in postoperative alignment or 2-year ODI between the groups (p>0.05 for all).
CONCLUSION(S): Compared to early staging (< 6 days) of ALIF and subsequent staged posterior fusion, delayed staging (>= 6 days) is associated with greater odds of 90-day complications, particularly infection. With the growing trend toward staged ASD surgeries, efforts should be made to shorten the interval between ALIF and subsequent posterior fusion. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Reoperations following adult spinal deformity (ASD) surgery place a significant burden on patient quality of life and overall health care costs. Despite the common knowledge of frequently occurring complications following ASD surgery that require reoperation, little is known on the cost and timing of these complications. Attempts to optimize the cost effectiveness of ASD surgery requires careful examination of the overall impact, frequency and timing of complications requiring reoperation on total cost of care. PURPOSE: The primary aim of our study was to ascertain the percentage of total cost of care attributed to reoperations, identify the costliest complications requiring reoperation following index surgery and to determine the timing of these complications. STUDY DESIGN/SETTING: Retrospective analysis of a prospective, multicenter study. PATIENT SAMPLE: ASD patients with >4 level fusion and eligible for minimum 2-year follow-up were included. OUTCOME MEASURES: Reoperation rates, Total cost of care.
METHOD(S): ASD patients with >4 level fusion with 2-year follow-up were included. Index and total episode of care (EOC) costs were calculated using Medicare's inpatient prospective payment system (IPPS) for MS-DRGs 453-460 and adjusted for inflation to 2020 real dollars. QALYs gained were calculated using baseline, 1-year, and 2-year SF-6D scores. Complication categories included: PJK (proximal junctional kyphosis), adjacent segment disease, pseudarthrosis, neurologic complications, malignment, implant malposition, and infections.
RESULT(S): DRG data for index and revision surgery was available for 505/889 patients. Mean age was 62.5+12.4 years, 76% women. Eighty-nine patients (18%) required a total of 114 reoperations (range 1-5 per patient). The mean index EOC for the whole cohort was $72,718, compared to a mean cost of $59,130 for each reoperation. Accounting for all reoperations, the tEOC in the revision group was 2.1-times higher than the non-revision group ($151,913 vs $71,978, p<0.0001). The 2-year QALY gain in the revision group was significantly higher than the non-revision group (0.08 vs 0.03, p<0.01). The two most common complications requiring reoperations were PJK (41.2%) and pseudarthrosis (36.8%). Reoperations for PJK and pseudoarthrosis collectively accounted for 77% of reoperation costs, but the majority (53%) occurred after 2 years of index surgery. Infections, implant malposition, or neurologic complications (33% each) were most common requiring reoperations within 30 days of index surgery.
CONCLUSION(S): PJK and pseudarthrosis were the two most common complications requiring reoperation and most occurred most frequently over 2 years after index surgery. Collectively, they contributed to 77% of the total reoperation costs. Efforts to optimize the cost effectiveness of ASD surgery should focus on effective methods to mitigate risk of PJK and pseudarthrosis. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Few studies investigate segmental lordosis restoration after long fusion with anterior (ALIF) vs transforaminal lumbar interbody fusion (TLIF) for adults with flatback deformity. PURPOSE: Our objective was to compare segmental lordosis restoration, health-related quality-of-life (HRQL), and complications associated with L4-S1 ALIF vs TLIF in operative treatment of flatback deformity. STUDY DESIGN/SETTING: Retrospective review of a prospectively collected multicenter consecutive case registry. PATIENT SAMPLE: Database enrollment required age >=18 years, scoliosis >=20degree, sagittal vertical axis (SVA) >=5cm, pelvic tilt >=25degree, or thoracic kyphosis >=60degree. OUTCOME MEASURES: Radiographic correction (including L4-S1 segmental lordosis), HRQL (Oswestry Disability Index [ODI], Short Form-36 [SF-36] scores, Scoliosis Research Society-22 [SRS-22r] scores), and complications.
Method(s): Prospective multicenter data were reviewed. Study inclusion required pelvic incidence to lumbar lordosis mismatch >=10degree (flatback), index ALIF vs TLIF at L4-L5 and/or L5-S1, and minimum 2-year follow-up. Cage details (height and lordosis) were also assessed.
Result(s): Of 222 consecutive patients, 157 (71%) achieved 2-year follow-up (age=63+/-10years, women=82%, ALIF=43%, TLIF=57%). Index operations had 12+/-3 posterior levels, iliac fixation=93%, and ALIF/TLIF at L4-L5 (66%) and L5-S1 (85%). ALIF vs TLIF cages were similar in height, but cage lordosis was greater for ALIF: L4-L5 (9degree+/-5degree vs 7degree+/-2degree, p=0.025) and L5-S1 (14degree+/-9degree vs 7degree+/-3degree, p<0.001). ALIF (vs TLIF) was associated with significantly more L4-S1 segmental lordosis at last follow-up (37degree+/-11degree vs 31degree+/-9degree, p<0.001) despite similar baseline measurement (32degree+/-15degree vs 31degree+/-14degree, p=0.705). Multiple regression demonstrated 1degree increase in L4-L5 ALIF cage lordosis led to 0.9degree increase in L4-L5 segmental lordosis (p=0.014), and 1degree increase in L5-S1 ALIF cage lordosis led to 0.5degree increase in L5-S1 segmental lordosis (p=0.005). For all patients, final alignment improved significantly (p<0.05): T12-S1 lordosis (25degree+/-17degree to 48degree+/-13degree), L4-S1 lordosis (32degree+/-14degree to 34degree+/-10degree),

BACKGROUND CONTEXT: Few guidelines exist regarding appropriate upper instrumented vertebra (UIV) selection for adult spinal deformity (ASD) patients undergoing long fusion to the pelvis. Fusion to upper thoracic (UT) spine may provide greater deformity correction and reduce proximal junctional failure (PJF) rates compared to fusions terminating at the thoracolumbar (TL) spine. Previous reports comparing outcomes for UT vs TL UIV for ASD surgery are confounded by discrepant patient cohorts. PSM analyses can be used to reduce selection bias and mimic patient randomization. PURPOSE: Use a propensity score matched (PSM) analysis to compare surgical and hospital data, deformity correction, complication rates, and patient reported outcomes (PROs) for demographically and radiographically matched ASD patients receiving TL vs UT UIV. STUDY DESIGN/SETTING: PSM analysis of ASD patients prospectively enrolled into a multicenter study. PATIENT SAMPLE: Surgically treated ASD patients. OUTCOME MEASURES: Numeric rating scale (NRS) back and leg pain, Scoliosis Research Society-22r questionnaire (SRS-22r), Short Form-36v2 questionnaire (SF-36), Oswestry Disability Index (ODI), estimated blood loss, duration of hospital stay, postoperative complications, revision spine surgery, PJF.
Method(s): ASD patients prospectively enrolled into a multicenter study from 2009-2018 were classified according to SRS-Schwab ASD Types. Study inclusion; 1) surgery for lumbar (L), sagittal (S) or mixed (M) deformities, 2) fusion to pelvis, 3) >=5 levels fused, 4) >=2 year follow up. Study exclusion; double major or thoracic scoliosis, thoracic hyperkyphosis (>70degree). UIV cohorts formed based on bimodal UIV distribution (TL=L2-T8 vs UT=T6-T1). PSM matched TL and UT for preop demographics, scoliosis, PI-LL, TK, SVA, TPA and osteotomies. Postop deformity correction, complications, and PROs were compared for UT vs TL in L, M, S deformities.
Result(s): Of 699 eligible patients, 417 (L [n=70], S [n=166] and M [n=198]) were evaluated. UT and TL had similar preop age, frailty, spine deformity, follow up, osteotomies performed (p>0.05). UT had greater blood loss in L and M deformities, greater SICU admissions for L and S, longer hospital and greater revision surgery for implant failures for all deformities than TL (p<0.05). UT had fewer PJF for L deformities (p<0.05). Deformity correction and PROM improvement was similar UT vs TL for all cohorts at last follow up (p>0.05).
Conclusion(s): The theoretical benefits of UT fusion were not demonstrated for matched L, S and M patients receiving long fusion to the pelvis. UT had greater blood loss, hospital stay and revision surgery for implant failures than TL. For select deformities surgeons should consider TL UIV rather than UT; however, more research is needed to determine best outcomes for fusion levels for ASD. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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STUDY DESIGN/METHODS:Longitudinal cohort. OBJECTIVES/OBJECTIVE:The aim of this study was to examine the relationship between patient satisfaction, patient-reported outcome measures (PROMs) and radiographic parameters in adult spine deformity (ASD) patients undergoing three-column osteotomies (3CO). SUMMARY OF BACKGROUND DATA/BACKGROUND:Identifying factors that influence patient satisfaction in ASD is important. Evidence suggests Scoliosis Research Society-22R (SRS-22R) Self-Image domain correlates with patient satisfaction in patients with ASD. METHODS:This is a retrospective review of ASD patients enrolled in a prospective, multicenter database undergoing a 3CO with complete SRS-22R pre-op and minimum 2-years postop. Spearman correlations were used to evaluate associations between the 2-year SRS Satisfaction score and changes in SRS-22R domain scores, Oswestry Disability Index (ODI), and radiographic parameters. RESULTS:Of 135 patients eligible for 2-year follow-up, 98 patients (73%) had complete pre- and 2-year postop data. The cohort was mostly female (69%) with mean BMI of 29.7 kg/m2 and age of 61.0 years. Mean levels fused was 12.9 with estimated blood loss of 2695 cc and OR time of 407 minutes; 27% were revision surgeries. There was a statistically significant improvement between pre- and 2-year post-op PROMs and all radiographic parameters except Coronal Vertical Axis. The majority of patients had an SRS Satisfaction score of ≥3.0 (90%) or ≥4.0 (68%), consistent with a moderate ceiling effect. Correlations of patient satisfaction was significant for Pain (0.43, P < 0.001), Activity (0.39, P < 0.001), Mental (0.38, P = 0.001) Self-Image (0.52, P < 0.001). ODI and Short-Form-36 Physical component summary had a moderate correlation as well, with mental component summary being weak. There was no statistically significant correlation between any radiographic or operative parameters and patient satisfaction. CONCLUSION/CONCLUSIONS:There was statistically significant improvement in all PROMs and radiographic parameters, except coronal vertical axis at 2 years in ASD patients undergoing 3CO. Improvement in SRS Self-Image domain has the strongest correlation with patient satisfaction.Level of Evidence: 3.

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.

STUDY DESIGN/METHODS:Retrospective review. OBJECTIVES/OBJECTIVE:The aim of this study was to define a surgical invasiveness threshold that predicts major complications after adult spinal deformity (ASD) surgery; use this threshold to categorize patients into quartiles by invasiveness; and determine the odds of major complications by quartile. SUMMARY OF BACKGROUND DATA/BACKGROUND:Understanding the relationship between surgical invasiveness and major complications is important for estimating the likelihood of major complications after ASD surgery. METHODS:Using a multicenter database, we identified 574 ASD patients (more than 5 levels fused; mean age, 60 ± 15 years) with minimum 2-year follow-up. Invasiveness was calculated as the ASD Surgical and Radiographic (ASD-SR) score. Youden index was used to identify the invasiveness score cut-off associated with optimal sensitivity and specificity for predicting major complications. Resulting high- and low-invasiveness groups were divided in half to create quartiles. Odds of developing a major complication were analyzed for each quartile using logistic regression (alpha = 0.05). RESULTS:The ASD-SR cutoff score that maximally predicted major complications was 90 points. ASD-SR quartiles were 0 to 65 (Q1), 66 to 89 (Q2), 90 to 119 (Q3), and ≥120 (Q4). Risk of a major complication was 17% in Q1, 21% in Q2, 35% in Q3, and 33% in Q4 (P < 0.001). Comparisons of adjacent quartiles showed an increase in the odds of a major complication from Q2 to Q3 (odds ratio [OR] 1.8; 95% confidence interval [CI]: 1.0-3.0), but not from Q1 to Q2 or from Q3 to Q4. Patients with ASD-SR scores ≥90 were 1.9 times as likely to have a major complication than patients with scores <90 (OR 1.9, 95% CI 1.3-2.9). Mean ASD-SR scores above and below 90 points were 121 ± 25 and 63 ± 17, respectively. CONCLUSION/CONCLUSIONS:The odds of major complications after ASD surgery are significantly greater when the procedure has an ASD-SR score ≥90. ASD-SR score can be used to counsel patients regarding these increased odds.Level of Evidence: 3.

STUDY DESIGN/METHODS:Retrospective review of a single-center spine database. OBJECTIVE:Investigate the intersections of chronological age and physiological age via frailty to determine the influence of surgical invasiveness on patient outcomes. SUMMARY OF BACKGROUND DATA/BACKGROUND:Frailty is a well-established factor in preoperative risk stratification and prediction of postoperative outcomes. The surgical profile of operative adult spinal deformity (ASD) patients who present as elderly and not frail has yet to be investigated. Our aim was to examine the surgical profile and outcomes of ASD patients who were not frail and elderly. METHODS:Included: ASD patients≥18 years old, ≥4 levels fused, with baseline(BL) and follow up data. Patients were categorized by ASD frailty index: Not Frail[NF], Frail[F], Severely Frail [SF]. An elderly patient was defined as ≥70 years. Patients were grouped into NF/elderly and F/elderly. SRS-Schwab modifiers were assessed at baseline and 1-year(0, +, ++). Logistic regression analysis assessed the relationship between increasing invasiveness, no reoperations, or major complications, and improvement in SRS-Schwab modifiers[Good Outcome]. Decision tree analysis assessed thresholds for an invasiveness risk/benefit cutoff point. RESULTS:598 ASD pts included(55.3yrs, 59.7%F, 28.3 kg/m2). 29.8% of patients were above age 70. At baseline, 51.3% of patients were NF, 37.5% F, and 11.2% SF. 66(11%) of patients were NF and elderly. 24.2% of NF-Elderly patients improved in SRS-Schwab by 1-year and had no reoperation or complication postoperatively. Binary regression analysis found a relationship between worsening SRS-Schwab, postop complication, and reoperation with invasiveness score(OR: 1.056[1.013-1.102], p = 0.011). Risk/benefit cut-off was 10(p = 0.004). Patients below this threshold were 7.9[2.2-28.4] times more likely to have a Good Outcome. 156 patients were elderly and F/SF with 16.7% having Good Outcome, with a risk/benefit cut-off point of <8 (4.4[2.2-9.0], p < 0.001). CONCLUSIONS:Frailty status impacted the balance of surgical invasiveness relative to operative risk in an inverse manner, while the opposite was seen amongst elderly patients with a frailty status less than their chronologic age. Surgeons should perhaps consider incorporation of frailty status over age status when determining realignment plans in patients of advanced age.Level of Evidence: ???

STUDY DESIGN/METHODS:Retrospective cohort analysis. OBJECTIVE:The aim of this study was to compare postoperative outcomes of Coflex interspinous device versus laminectomy. SUMMARY OF BACKGROUND DATA/BACKGROUND:Coflex Interlaminar Stabilization device (CID) is indicated for one- or two-level lumbar stenosis with grade 1 stable spondylolisthesis in adult patients, as an alternative to laminectomy, or laminectomy and fusion. CID provides stability against progressive spondylolisthesis, retains motion, and prevents further disc space collapse. METHODS:Patients ≥18 years' old with lumbar stenosis and grade 1 stable spondylolisthesis who underwent either primary single-level decompression and implantation of CID, or single-level laminectomy alone were included with a minimum 90-day follow-up at a single academic institution. Clinical characteristics, perioperative outcomes, and postoperative complications were reviewed until the latest follow-up. χ2 and independent samples t tests were used for analysis. RESULTS:Eighty-three patients (2007-2019) were included: 37 cases of single-level laminectomy (48.6% female) were compared to 46 single-level CID (50% female). CID cohort was older (CID 69.0 ± 9.4 vs. laminectomy 64.2 ± 11.0, P = 0.042) and had higher American Society of Anesthesiologists (ASA) grade (CID 2.59 ± 0.73 vs. laminectomy 2.17 ± 0.48, P = 0.020). CID patients had higher estimated blood loss (EBL) (97.50 ± 77.76 vs. 52.84 ± 50.63 mL, P = 0.004), longer operative time (141.91 ± 47.88 vs. 106.81 ± 41.30 minutes, P = 0.001), and longer length of stay (2.0 ± 1.5 vs. 1.1 ± 1.0 days, P = 0.001). Total perioperative complications (21.7% vs. 5.4%, P = 0.035) and instrumentation-related complication was higher in CID (10.9% vs. 0% laminectomy group, P = 0.039). There were no other significant differences between the groups in demographics or outcomes. CONCLUSION/CONCLUSIONS:Single-level CID devices had higher perioperative 90-day complications, longer operative time, length of stay, higher EBL compared to laminectomies alone. Similar overall revision and neurologic complication rates were noted compared to laminectomy at last follow-up.Level of Evidence: 3.