Faculty Bibliography

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: 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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OBJECTIVE:To prioritize the cervical parameter targets for alignment. METHODS:Included: cervical deformity (CD) patients (C2-7 Cobb angle > 10°, cervical lordosis > 10°, cervical sagittal vertical axis [cSVA] > 4 cm, or chin-brow vertical angle > 25°) with full baseline (BL) and 1-year (1Y) radiographic parameters and Neck Disability Index (NDI) scores; patients with cervical [C] or cervicothoracic [CT] Primary Driver Ames type. Patients with BL Ames classified as low CD for both parameters of cSVA ( < 4 cm) and T1 slope minus cervical lordosis (TS-CL) ( < 15°) were excluded. Patients assessed: meeting minimum clinically important differences (MCID) for NDI ( < -15 ΔNDI). Ratios of correction were found for regional parameters categorized by primary Ames driver (C or CT). Decision tree analysis assessed cutoffs for differences associated with meeting NDI MCID at 1Y. RESULTS:Seventy-seven CD patients (mean age, 62.1 years; 64% female; body mass index, 28.8 kg/m2). Forty-one point six percent of patients met MCID for NDI. A backwards linear regression model including radiographic differences as predictors from BL to 1Y for meeting MCID for NDI demonstrated an R2 of 0.820 (p = 0.032) included TS-CL, cSVA, McGregor's slope (MGS), C2 sacral slope, C2-T3 angle, C2-T3 SVA, cervical lordosis. By primary Ames driver, 67.5% of patients were C, and 32.5% CT. Ratios of change in predictors for MCID NDI patients for C and CT were not significant between the 2 groups (p > 0.050). Decision tree analysis determined cutoffs for radiographic change, prioritizing in the following order: ≥ 42.5° C2-T3 angle, > 35.4° cervical lordosis, < -31.76° C2 slope, < -11.57-mm cSVA, < -2.16° MGS, > -30.8-mm C2-T3 SVA, and ≤ -33.6° TS-CL. CONCLUSION/CONCLUSIONS:Certain ratios of correction of cervical parameters contribute to improving neck disability. Prioritizing these radiographic alignment parameters may help optimize patient-reported outcomes for patients undergoing CD surgery.

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: 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: 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: Rod failure and pseudarthrosis are common complications following the surgical treatment of adult spinal defomity (ASD). Many strategies have been employed in mitigating these problems, such as interbody fusion, multiple rods, use of more effective biologics, and optimizing spinal alignment. We aimed to study the frequency and type of rod failures in a large ASD population over time. PURPOSE: To study the frequency and type of rod failures in a large ASD population over time. STUDY DESIGN/SETTING: Retrospective review of prospective data. PATIENT SAMPLE: This study included 647 adult spinal deformity patients surgically treated between 2008 and 2018. OUTCOME MEASURES: Rod failures.
METHOD(S): ASD patients with a fusion extended from minimum L1 to pelvis and min 2-year follow-up were included. Radiographs and records were examined to identify characteristics of the rod failures: timing, unilateral vs bilateral, vertebral level, unilateral progressing to bilateral failure, revision and failure rates over time.
RESULT(S): Among the study population, 647/1052 patients met inclusion criteria (age: 64+/-10 yrs., 78% F, BMI: 28.3+/-5.7, Mean follow-up: 37 months +/-13). Surgeries for these patients were performed from 2008 to 2018. The UIV was T7 or above in 306 and T8 or below in 338 patients, most frequent UIV: T4 (121) and T10 (208). A total of 146 patients had a 3COs; 435 had interbody fusion with 187 ALIF, 202 TLIF,135 XLIF; 286 patients had BMP use post only and 203 had BMP use interbody and posteriorly. Overall rod failure rate was 135/647 (21%), of which 9.3% occurred before by 2 years postop. Mean days to failure was 795 day +/- 485 (Median 733). Most frequent failures were in the lower lumbar spine L3-4 (32) 24%, L4-5 (34) 25% and L5-S1 (44) 32%. Of the 97 Unilateral failures, 35 (36.1%) were revised and only 8 progressed to bilateral failure of which 6/8 were revised; 46 Bilateral failure, 24 (52.2%) were revised.Kaplan-Meier analysis shows a survival rate of 89.7% at 2 years with decrease of 5% per year. No significant difference was found between the first 5 years and last 5 years. Comparison of primary vs revision index procedures did not reveal any differences in time to failure nor time to revision. Use of BMP improved survival rate to 91.2% compared to no BMP 83.4% at 2 years.
CONCLUSION(S): Rod failures remain a common complication when treating ASD with a rate of 21%. Among those rod failures, 9.3% occurred within 2 years. The most frequent sites of failure were in the lower lumbar spine. Unilateral failures underwent a lower rate of revision than bilateral. BMP increased rod survivability. Kaplan-Meier analysis demonstrated a survival rate of 89.7% at 2 years with a decrease of 5% per year. The failure rate has not improved when comparing the first 5 years. to last 5 years. We must continue to seek solutions to improve rod durability challenges to improve long-term outcomes. 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: Hounsfield unit values (HU) from computed tomography (CT) have been used to informally assess bone density in patients undergoing spine fusion procedures. HUs are easily obtained from a standard preoperative CT scan, and unlike Dual X-ray Absorptiometry analysis (DEXA) one can focus on specific regions of interest, such as the vertebral body of a planned upper-instrumented vertebrae (UIV). There is still a relative lack of literature on the reliability and utility of HUs to both identify patients with low BMD and guide surgical decision making. PURPOSE: To determine whether there was a significant difference in preoperative HUs, measured at the UIV, in patients that had a bone-density related complication (DRC) within 2 years of their spinal fusion. STUDY DESIGN/SETTING: A retrospective comparative study at a single academic institution. PATIENT SAMPLE: Patients 55 years or older that underwent a spinal fusion procedure in 2017 at a single academic institution. OUTCOME MEASURES: Occurrence of proximal junctional kyphosis, proximal junctional failure, pseudarthrosis, screw loosening or pullout, hardware failure and adjacent segment disease (ASD).
METHOD(S): Baseline preoperative demographic information, smoking history, levels fused, UIV and status as a revision procedure were recorded. All postoperative notes and images for 2 years post-procedure were reviewed for the presence of proximal junctional kyphosis, proximal junctional failure, pseudarthrosis, screw loosening or pullout, hardware failure, and ASD. HUs were measured via regions of interest drawn within the cancellous bone of the mid-vertebral body at the UIV of all patients. Patients were divided into 2 groups for comparison, those who experienced a DRC within 2 years and those who did not. Student's t-test was performed to compare HUs between the groups, chi-square analysis was performed for categorical variables. Dichotomous logistical regression was performed to analyze the relationship between density related complications and HU at the UIV, patient BMI, revision procedure, history of smoking, gender, UIV and number of levels fused. Significance was set at p<0.05.
RESULT(S): A total of 172 consecutive fusion patients with a preoperative CT scan were reviewed. Of these, 49 were revision procedures. 66 had a UIV in the cervical spine, 10 had a UIV in the thoracic spine and 95 had a UIV in the lumbar spine. Ninety-nine were 1 or 2 level fusions, 49 were 3 or 4 level fusions and 23 were long fusions with 4+ levels involved. Forty-eight patients had a DRC. Baseline demographics were similar between the 2 groups, with the exception of more revision procedures in the DRC group (p<0.001). The mean HUs of the UIV in the cohort that had a DRC was 168.92, as compared to 252.66 in the no-DRC group (p<0.001). Regression analysis revealed that low HUs at the UIV and revision procedures were independent risk factors for a DRC. For every 10 unit decrease in HUs, the odds of a DRC rose by 6%. When thoracic and lumbar fusions were analyzed the mean HUs at the UIV in the DRC group were 108.5 vs 152.6 (p<0.001). When cervical fusions were analyzed separately the mean HUs in the DRC group were 308 vs 383.4 (P=0.014).
CONCLUSION(S): To our knowledge, this is the first study that compares HUs measured at the UIV to the rate of density related complications for single and multilevel fusions in the cervical, thoracic and lumbar spine. This study found that HUs measured at the UIV of a fusion were significantly lower in patients that went on to have a density related complication within 2 years of their index procedure. 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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