Faculty Bibliography

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: Adult spinal deformity (ASD) surgery is costly and carries a high complication rate. It is therefore very important to optimize value (cost-per-QALY) or cost-utility in ASD surgery. To identify targets for improvement, we compared the influence of patient factors, measured by frailty, vs surgical factors, measured by surgical invasiveness (SI), on 2-year cost-utility. Patient frailty is an approximation of baseline patient health status, whereas SI represents extensiveness of the surgical intervention. Data comparing the relative importance of these aggregate measures on cost-utility are limited. Additionally, this analysis can serve to help identify the most impactful modifiable factors in the value equation. PURPOSE: The aim of this study was to assess whether frailty or SI is a more important determinant of 2-year cost-utility in ASD surgery. STUDY DESIGN/SETTING: Prospective, multicenter study. PATIENT SAMPLE: ASD patients with >4-level fusion and eligible for minimum 2-year follow-up were included. OUTCOME MEASURES: Two-year cost-per-QALY.
METHOD(S): Index and total episode of care (EOC; iEOC; tEOC) cost was calculated using Medicare's inpatient prospective payment system (IPPS) for MS-DRGs 453-460. All costs were adjusted for inflation to 2020 US dollar values. QALYs gained were calculated using baseline, 1-year, and 2-year SF-6D scores. A discount rate of 3% was assumed. Cost-per-QALY was determined by calculating total EOC per cumulative QALY at two years. Patients were categorized as not-frail (NF, <0.3), frail (F, 0.3<= to <0.5), and severely frail (SF, >0.5). SI was categorized as low-SI (SI<90) and high-SI (SI>90). A generalized linear model with gamma error distribution and log link was used to estimate the association between frailty and SI on cost-per-QALY. All analyses were controlled for gender and blood loss. Other variables commonly adjusted for (ie, age, levels fused) were intentionally not controlled for in this analysis to avoid collinearity with either frailty or SI.
RESULT(S): DRG data for index and revision surgery was available for 505/889 patients. Mean age was 62.5+12.4years, 76% were women, and 91% were Caucasian. Of the total patients,72% demonstrated positive gain in QALY at 2 years (0.12+0.09, p<0.001) compared to baseline. The mean iEOC was $72,717, tEOC was $86,066, and cost-per-QALY was $52,357. Eighty-nine patients had 114 (range 1-5) revisions (17.6%) compared to 416 without. The tEOC in revision group was $151,913 compared to $71,978 in the non-revision group with 2-year cost-per-QALY 98,262 compared to 42,537, respectively. On adjusted analysis, F and SF patients compared to NF patients had significantly higher cost-per-QALY (p<0.0001 for all comparisons) regardless of the surgical invasiveness. However, SI was not significantly associated with cost-per-QALY regardless of patient's frailty.
CONCLUSION(S): Increasing levels of frailty were associated with significantly and incrementally higher values of 2-year cost-per-QALY in both low and high SI groups. However, within each frailty group, the high and low SI groups had equivalent cost-per-QALY. Frailty appears to be a better determinant of 2-year cost-per-QALY compared to surgical invasiveness. Surgeons should place more importance on modifiable patient factors compared to surgical factors to improve or optimize 2-year cost-utility in ASD surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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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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BACKGROUND CONTEXT: A previous study by Pellise et al identified that a lowest instrumented vertebrae (LIV) at the pelvis, frailty, and sagittal deformity (global sagittal alignment [SVA], lordosis gap [PI-LL], T1 sagittal tilt [T1Slope]) were strong preoperative predictors of major complications. In addition to the preoperative predictors, blood loss and surgical time were strong predictors that occur operatively. It is unknown whether being at risk by these criteria has an effect on cost of surgery. PURPOSE: To determine whether previously established risk stratification criteria will reduce operative costs. STUDY DESIGN/SETTING: Retrospective cohort study of a prospectively collected multicenter ASD database. PATIENT SAMPLE: This study included 952 ASD patients. OUTCOME MEASURES: Health-related quality of life measures (HRQLs), quality adjusted life years (QALYs), utility gained, ODI, total cost.
METHOD(S): Adult spinal deformity (ASD) patients with complete baseline (BL) and 2-year (2Y) HRQLs and radiographic data were included. Frailty score, sagittal deformity measures, blood loss, and surgical time were divided into tertiles, with the highest tertile being high risk. Published methods converted ODI to SF-6D. QALYs utilized a 3% discount rate for residual decline to life expectancy (LE, 78.7 years). Cost was calculated using the PearlDiver database and assessed for complications/major complications and comorbidities according to CMS.gov definitions. Cost per QALY at 2Y and LE were calculated for additive risk factors (LIV at pelvis, high frailty, any high sagittal deformity measure, high blood loss, high surgical time). These costs represented national averages of Medicare pay-scales for services within a 30-day window including length of stay and death differentiated by complication/comorbidity, revision, and surgical approach. Internal cost data were based on individual patient DRG codes.
RESULT(S): Of 926 patients included, 118 did not meet any risk criteria, 171 met 1, 207 met 2, 151 met 3, 56 met 4, and 3 met 5 (these 3 patients were excluded due to small sample size). There was a significant trend (R2=0.897) in terms of national average cost at 2-years with increasing amount of risk measures met, as cost increased by $11,566 with each additional risk factor. Amount of risk factors met had a positive correlation to baseline ODI (0: 30.89; 1: 39.66; 2: 46.96; 3: 51.59; 4: 54.69; p<0.001) and 2Y ODI (0: 18.06; 1: 22.55; 2: 27.53; 3: 34.23; 4: 38.54; p<0.001). When analyzing initial surgical cost by DRG code, there was a $3,844 increase in cost per risk factor (R2=0.8703). Patients meeting 2 risk factors had the highest ODI improvement from BL to 2Y (p=0.06). QALYs gained at LE decreased by 0.0756 per risk factor (R2=0.8153). National average cost per QALY at 2Y increased by $45,852 per risk factor (R2=0.4151), and cost per QALY at LE increased by $15,759 per risk factor (R2=0.8822).
CONCLUSION(S): Increasing risk factors involving frailty, baseline deformity, and operative factors reduce cost effectiveness by increasing total cost and reducing QALYs. Preoperative or intraoperative measures to reduce a patient's amount of applicable risk factors would concurrently reduce operative cost and improve cost-effectiveness. Awareness of non-modifiable risk factors may also help educate surgical approach. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) are two of the most challenging complications in adult spinal deformity (ASD) surgery. Bone quality has been identified as an important factor in outcomes of ASD patients. The association between Hounsfield units (HU) on CT scan at UIV and L1, and PJK occurrence remains poorly defined. Previous published literature has found HU<120 to indicate poor bone health. PURPOSE: Hounsfield units at the UIV and L1 can predict the occurrence of PJK in ASD. STUDY DESIGN/SETTING: Retrospective review of prospectively collected multicenter data. PATIENT SAMPLE: A prospective database with inclusion criteria of age >18, PI-LL >10, PT>25, SVA>5, TK >60 and Cobb >20 was retrospectively reviewed and patients included only if complete: preop Hounsfield unit data at L1 and UIV, PJK prophylaxis data (PRPH), fusion to the pelvis and 2-year radiographic data. OUTCOME MEASURES: Development of PJK or PJF. These were defined as per Glattes et al as: PJA <-10 & DELTAPJA < -10 at 2 years postoperation and PJK as per Lafage et al as: PJA <-28 & DELTAPJA < -22 at 2 years or revision surgery for PJK before 2 years postoperation. Health related quality of life measures (HRQL) included SF 36, ODI, SRS-22.
Method(s): Retrospective review of prospectively collected multicenter data. Data analyzed with SPSS software. Multilinear regression models were run to identify independent variables associated with PJK and PJF. Odds ratios calculated. Decision tree analysis used to see if the effect of HU is not conditional of other parameters.
Result(s): This study included 240 patients, avg age 64 (31-84), BMI 28.9 (17.7-46), CCI 2.1 (0-8), and 188 (78.3%) females. Of the total patients, 17.1% (41) reported osteoporosis and 56.3% had previous spine surgery. There was significant in improvement in all HRQL from pre- to postsurgery (p<0.001). PJK occurred in 45% (108/240) and PJF in 13% (31/240). HU as an independent variable did not correlate with PJK magnitude. When controlling for PRPH, there was no correlation. Multilinear regression found that HU was not an independent predictor of PJK or PJF. PJK/F was subclassified as bony (bPJK) and analysis revealed that bPJK had larger angular deformity, higher rate with LT UIV, and associated with HU at UIV (p=0.011) as did bony PJF (p=0.037). UIV HU<120 was associated with bPJK (p=0.029) and bPJF (p=0.000). Odds ratio for UIV HU<120 to develop bPJK is 2.33 (CI: 1.07-5.08) and 4.67 for bPJF (CI: 1.87-11.7). Decision tree analysis, however, showed UIV HU was a conditional predictor of PJK in patients who have a PI-LL corrected >13 and with global realignment >19.
Conclusion(s): Hounsfield units alone are not an independent predictor of PJK or failure in ASD. Decision tree analysis, however, reveals that in the setting of patients requiring major global realignment and lordosis generation, HU are predictive of PJK. Furthermore, UIV HU<120 is 2.3 times more likely to result in bPJK and 4.6 times more likely in bPJF. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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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: Surgeons may preferentially limit fusion levels for younger vs older ASD patients to maintain motion segments and optimize postoperative function. Few data exist comparing the functional impact of upper thoracic (UT) vs thoracolumbar (TL) upper instrumented vertebra (UIV) in younger vs older ASD patients undergoing long fusion to the pelvis. PURPOSE: Evaluate patient reported functional impact of UT vs TL UIV in younger vs older ASD patients undergoing long fusion to the pelvis. STUDY DESIGN/SETTING: Propensity score matched (PSM) analysis of ASD patients prospectively enrolled into a multicenter study. PATIENT SAMPLE: Surgically treated ASD patients prospectively enrolled into multicenter study. 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.
METHOD(S): Surgically treated ASD patients prospectively enrolled into a multicenter ASD study were divided into 2 age groups (younger= <65 years, older= > 65 years) and separated according to UIV (TL= L2-T7; UT= T6-T1). Study inclusion criteria; 1) surgery for Lumbar (L), Sagittal (S), or Mixed (M) deformities (as per SRS-Schwab ASD classification), 2) fusion to the pelvis, 3) minimum 5 levels fused, and 4) minimum 2 year postop follow up. Surgery for double major or thoracic scoliosis were excluded. PSM was used to match preop patient demographics, scoliosis, and sagittal spinopelvic parameters including PI-LL, TK, SVS, and TPA. Surgical data evaluated and impact of UIV upon patient reported functional outcomes compared for UT vs TL for younger vs older.
RESULT(S): From 2008-2018, 435 of 717 eligible surgically treated patients were evaluated; younger (n=193; mean age 57.6 years) and older (n=242; mean age 72.3 years), mean levels fused UT=17.4, TL=10.7 (p<0.05). Preop spine deformity, demographics, and performance of osteotomies were similar for matched UT vs TL in younger and older (p>0.05). Surgical blood loss, duration of SICU and hospital stay was greater for UT vs TL in younger and older (p<0.05). UT had more revision surgery than TL due to implant failures in younger (20% vs 3%) and older (16% vs 1%), respectively (p<0.05). Older UT had more major complications than older TL (65% vs 30%). At minimum 2 year postoperative follow up spine deformity correction and all PROMs (including improvements and final values) including SRS-22r activity, SF-36 physical function, SF-36 role physical, SF-36 social function and SF-36 vitality were similar UT vs TL in younger and older (p>0.05).
CONCLUSION(S): Younger ASD patients fused to the pelvis do not report more physical restrictions for UT vs TL UIV compared to older ASD patients, however blood loss, SICU and hospital stay and complications were greater for UT vs TL in younger and older cohorts. When deciding upon UIV for ASD patients, the minimal impact of UT vs TL UIV upon patient reported outcomes must be offset by cognizance of a longer hospital stay and potential for greater postoperative complications for UT fusions especially in older patients. 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 fractional curve correction after long fusion with transforaminal (TLIF) vs anterior lumbar interbody fusion (ALIF) for adult symptomatic thoracolumbar/lumbar scoliosis (ASLS). PURPOSE: Our objective was to compare fractional correction, health-related quality-of-life (HRQL), and complications associated with L4-S1 TLIF vs ALIF in ASLS operative treatment. STUDY DESIGN/SETTING: Retrospective review of a prospectively collected multicenter consecutive case registry. PATIENT SAMPLE: Database enrollment required age >=18 years, scoliosis >=20, sagittal vertical axis (SVA) >=5cm, pelvic tilt >=25, or thoracic kyphosis >=60. OUTCOME MEASURES: Radiographic correction (including L4-S1 fractional curve), 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 was reviewed. Study inclusion required fractional curve >=10degree, thoracolumbar/lumbar curve >=30degree, index TLIF vs ALIF at L4-L5 and/or L5-S1, and minimum 2-year follow-up. TLIF and ALIF patients were propensity-matched using number and type of interbody fusion at L4-S1.
RESULT(S): Of 135 potentially eligible consecutive patients, 106 (78.5%) achieved minimum 2-year follow-up (age=60.6+/-9.3years, women=85.8%, TLIF=44.3%, ALIF=55.7%). Index operations had 12.2+/-3.6 posterior levels, iliac fixation=86.8%, and TLIF/ALIF at L4-L5 (67.0%) and L5-S1 (84.0%). ALIF had greater cage height (10.9+/-2.1 vs 14.5+/-3.0mm, p=0.001) and lordosis (6.3degree+/-1.6degree vs 17.0degree+/-9.9degree, p=0.001) and longer operative duration (6.7+/-1.5 vs 8.9+/-2.5hrs, p<0.001). Final alignment improved significantly (p<0.05): fractional curve (20.2degree+/-7.0degree to 6.9degree+/-5.2degree), maximum coronal Cobb (55.0degree+/-14.8degree to 23.9degree+/-14.3degree), C7-sagittal vertical axis (5.1+/-6.2 to 2.3+/-5.4cm), pelvic tilt (24.6degree+/-8.1degree to 22.7degree+/-9.5degree), and lumbar lordosis (32.3degree+/-18.8degree to 51.4degree+/-14.1degree). Matched analysis demonstrated comparable fractional correction (TLIF=-13.6degree+/-6.7degree vs ALIF=-13.6degree+/-8.1degree, p=0.982). Final HRQL improved significantly (p<0.05): ODI (42.4+/-16.3 to 24.2+/-19.9), SF-36 Physical Component Summary (PCS, 32.6+/-9.3 to 41.3+/-11.7), SRS-22r (2.9+/-0.6 to 3.7+/-0.7). Matched analysis demonstrated worse ODI (30.9+/-21.1 vs 17.9+/-17.1, p=0.017) and PCS (38.3+/-12.0 vs 45.3+/-10.1, p=0.020) for TLIF at last follow-up (despite no difference in these parameters at baseline). Total complication rate per patient was not different (TLIF=76.6% vs ALIF=71.2%, p=0.530), but significantly more TLIF patients had rod fractures (RF) (TLIF=28.6% vs ALIF=7.1%, p=0.036). Multiple regression demonstrated 1-mm increase in L4-L5 TLIF cage height lead to 2.2degree reduction in L4 coronal tilt (p=0.011), and 1degree increase in L5-S1 ALIF cage lordosis lead to 0.4degree increase in L5-S1 segmental lordosis (p=0.045).
CONCLUSION(S): Operative ASLS treatment with L4-S1 TLIF vs ALIF demonstrated comparable fractional curve correction (66.7% vs 64.8%) despite significantly larger, more lordotic ALIF cages. TLIF cage height had significant impact on leveling L4 coronal tilt, whereas ALIF cage lordosis had significant impact on lumbosacral lordosis restoration. Advantages of TLIF may include reduced operative duration; however, associated HRQL was inferior and more RFs were detected in this study. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adult spinal deformity (ASD) patients experience markedly decreased health-related quality of life along many dimensions. PURPOSE: We hypothesized that ASD surgery would be associated with improved work- and school-related productivity, as well as decreased rates of absenteeism. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: Only patients eligible for 2-year follow-up were included, and those with a history of previous spinal fusion were excluded. OUTCOME MEASURES: The primary outcome measures in this study were SRS-22r questions 9 ("What is your current level of work/school activity?") and 17 ("In the last 3 months have you taken any days off of work, including household work, or school because of back pain?").
METHOD(S): A repeated measures mixed linear regression was used to analyze responses over time among patients managed operatively (OP) vs nonoperatively (NON-OP). Results were further stratified by baseline employment status, age, SVA, PI-LL, and deformity curve type.
RESULT(S): In total, 1,188 patients were analyzed. Of those, 66.6% (n=792) were managed operatively. The vast majority (78.9%, n=934) were female. Patients were relatively evenly distributed across age groups (27.6% 0-49; 21.1% 50-59; 30.1% 60-69; 21.2% >=70). At baseline, the mean percentage of activity at work/school was 56.4% (SD 35.4%), and the mean days off from work/school over the past 90 days was 1.6 (SD 1.8). Patients undergoing ASD surgery exhibited an 18.1% absolute increase in work/school productivity at 2-year follow-up vs baseline (p<0.0001), while no significant change was observed for the nonoperative cohort (p>0.5). Similarly, the OP cohort experienced 1.1 fewer absent days over the past 90 days at 2 years vs baseline (p<0.0001), while the NON-OP cohort showed no such difference (p>0.3). These differences were largely preserved after stratifying by baseline employment status, age group, SVA, PI-LL, and deformity curve type.
CONCLUSION(S): ASD patients managed operatively exhibited an average increase in work/school productivity of 18.1% and decreased absenteeism of 1.1 per 90 days at 2-year follow-up, while patients managed non-operatively did not exhibit change from baseline. Given the age distribution of patients in this study, these findings should be interpreted as pertaining primarily to obligations at work or within the home. Further study of the direct and indirect economic benefits of ASD surgery to patients is warranted. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Cervical alignment and cervical deformity surgery are complex topics. Recently, a score inspired by work on thoracolumbar alignment was developed for cervical alignment (cervical deformity score, CDS). While this score was designed to predict early mechanical failures, its association with patient reported outcomes (PROM) remains unclear. PURPOSE: Investigate the association between PROM, complications, and a newly described cervical deformity score. STUDY DESIGN/SETTING: Retrospective review of prospective multicenter database. PATIENT SAMPLE: A total of 102 adult cervical deformity (CD) patients with at least 1 year follow-up. OUTCOME MEASURES: NDI, neck pain, EQ5D, complication rates.
Method(s): CD patients with baseline and 1-year follow-up were included. Postoperative CDS was constructed using offset from age-adjusted values: SVA [(age -55)*2+25], T1 Slope [(age -55)/4 + 28.7], and TS minus CL [cst: between 26.5 and 14.5degree]. Points were assigned based on the offset from alignment targets and the CDS was the sum of the three individual scores. Association with patient-reported outcomes was investigated using Pearson's correlations. Comparison of CDS between patients with and without complication within 1-year was conducted. Logistical regression controlling for demographic and comorbidities was conducted to identify if CDS was an independent predictor of complications.
Result(s): A total of 102 patients met inclusion criteria (61.7yo+/-10, 66.7% F); 37.6% of them had a history of previous cervical surgery (16.7% previous ACDF, 11.7% previous posterior fusion). Preoperatively, they had elevated disability (NDI: 47.1+/-18.1), pain (NSR Neck: 6.6+/-2.5), myelopathy (mJOA: 13.6+/-2.7) and lower general health (EQ5D: 0.74+/-0.07). They also presented with an overall cervical kyphotic alignment (C2-C7: -6.3degree+/-20.9), a moderate cervical anterior alignment (cSVA: 39mm+/-20; TS-CL: 37.9degree+/-19.4) and a posterior global thoracolumbar alignment (SVA: -3mm+/-68). The median of number of levels fused was 7 [4-9], with 49% treated with a posterior approach and 30.4% with a combined approach; 83.2% received an osteotomy, 44.6% some posterior osteotomy, 16.8% grade 6 or 7. The mean operative time was 368min+/-208, median EBL was 525cc [200 1025], and LOS was 5 days [4 8]. At 1 year, patients improved significantly in terms of disability (NDI: 36.2+/-20.7, 60.8% reached MCID), pain (NSR: 4.1+/-2.9) and general health (EQ5D: 0.79+/-0.08) (all p<0.001). The cervical alignment significantly changed (C2-C7: 7.8+/-14.5m; cSVA: 34mm+/-15; TS-CL: 28.9degree+/-12.6 all p <0.002), with a 1-year CDS of 1.68+/-2.46 (prctl [0 3.25]). There was a significant association between increased CDS and increased disability (r=0.273), pain (r=0.336) and lower general health (r=-0.283). Patient with a lower disability level (NDI<20) had a significantly lower CDS (0.71+/-2.3 vs 2.16+/-2.4 p<0.004). Patients without any complications before 1 year had a lower CDS (0.78+/-2.33 vs 2.18+/-2.40 p=0.005), as did patients without major complications (1.36+/-2.27 vs 2.50+/-.78 p=0.037). Deeper analysis revealed significant differences in terms of CDS for patients experiencing cardiopulmonary, instrumentation and radiographic complications (p<0.05). Multivariate analysis, controlling for age and comorbidities, show 1-year CDS to be a significant predictor of complication (p=0.002, OR=1.409).
Conclusion(s): With better outcomes and lower complication rate, maintaining a proportionate alignment postoperatively can result in superior outcomes following CD surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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