Faculty Bibliography

BACKGROUND CONTEXT: Hyperextension of C0-C2 is a painful compensatory mechanism used to maintain horizontal gaze that is analogous to high pelvic tilt to maintain upright posture. The magnitude and impact of relaxation of this hyperextension following CD correction are not well understood. PURPOSE: To investigate whether correction of cervical sagittal malalignment allows for relaxation of C0-C2 hyperextension and improved clinical outcome. STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: This study included 65 ACD patients with 1- or 2-year follow-up. OUTCOME MEASURES: Radiographic alignment, range of motion (ROM).
Method(s): CD patients undergoing surgery short of the occiput and the pelvis were included. In addition to the classic alignment parameters, ROM and reserve of extension were calculated across the C2-C7 and C0-C2 segments. After describing the cohort in terms of preoperative information, correlations and hierarchical stepwise regressions investigated the association between C2-C7 correction and change in C0-C2 reserve of extension while controlling for maintenance of horizontal gaze. Stratification by DELTAC2-C7 percentile was conducted followed by paired t-tests to investigate changes in TK, C0-C2 and reserve of extension within each percentile.
Result(s): Sixty-five patients were included (61.8yo+/-9.6, 68%F). At baseline, they presented with a cervical kyphotic alignment (C2-C7: -11.7degree+/-18.2; TS-CL: 38.6degree+/-18.6), a negative global alignment (SVA: -12mm+/-71), and hyperlordosis at C0-C2 (33.2degree+/-11.8). The ROM was 25.7degree+/-17.7 and 21.3degree+/-9.9 at C2-C7 and C0-C2, respectively, with an associated reserve of extension of ~9degree for each segment. Limited C0-C2 ROM and reserve of extension significantly correlated with the Neck Disability Index (r=-0.371 & -0.394) and with decreased general health (r=0.455 & 0.512) (all p<0.005) The mean number of levels treated was 7.0+/-3.1 (24.6% ACDF, 43.1% posterior), with 49.2% of the patients receiving an osteotomy, and 16.9% a 3CO. At 1 year, C2-C7 increased to 5.5degree+/-13.4, SVA became neutral (12mm+/-54), C0-C2 decreased to 27.7degree+/-11.7, and TK increased to -49.4+/-18.1 (all p <0.001). At C2-C7 ROM decreased significantly to 9.5degree+/-14.1, and increased to 27.6degree+/-8.1 at C0-C2 without change in reserve of extension. The horizontal gaze significantly improved (4.5+/-13.3 vs -0.5+/-9.3 p=0.003). Controlling horizontal gaze, change in C2-C7 lordosis significantly correlated with increased TK (r=-0.615, p<0.01), decreased C0-C2 (r=-0.686, p<0.001), and increased C0-C2 reserve of extension (r=0.414, p<0.015). Larger C0-C2 ROM and reserve of extension correlated with decreased in Neck Disability Index (r=-0.571 & -0.470 p<0.05). Stratification by DELTAC2-C7 percentile highlighted the reciprocal change above and below the fusion. Within the lowest percentile (DELTAC2-C7: 2degree+/-9.6), no significant difference was noticed between pre and 1 year, while within the highest percentile (DELTAC2-C7: -42.8+/-14.1), C0-C2 decreased (-9.7degree+/-10.5, p=0.001), TK kyphosis increased (14.3degree+/-7.5, p<0.001) and C0-C2 reserve of extension increased (5.8degree+/-6.4, p=0.026). Subanalysis on patients with available 2-year data (N=42) demonstrated similar trends.
Conclusion(s): Correction of cervical malalignment can significantly impact proximal (C0-C2) and distal (T2-T12) compensation. Restoration of a more natural alignment resulted in an increase of the reserve of extension between C0-C2 and was associated with improved clinical outcomes. 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: Cervical deformity (CD) surgery can markedly improve patient quality of life. The longevity of CD correction and the mechanism of alignment deterioration are not well understood. PURPOSE: To investigate preoperative risk factors and failure mechanisms that erode CD corrections and the impact on functional outcomes. STUDY DESIGN/SETTING: Retrospective review of a prospective CD database. PATIENT SAMPLE: This study included 155 operative CD patients with baseline (BL) and 1-year follow-up. OUTCOME MEASURES: Alignment at baseline, 3 months, 6 months and 1 year: cervical sagittal vertical axis (cSVA), C2 Slope (C2S), T1 slope (T1S), C2-C7 lordosis (CL), T1S-CL mismatch (TS-CL), Neck Disability Index (NDI), Modified Japanese Orthopaedic Association score (mJOA).
Method(s): A retrospective review of a prospective database of operative CD patients was analyzed. Patients with baseline, 3-month, 6-month and 1-year cervical radiographs were included. Cervical sagittal vertical axis (cSVA) <4cm was used to categorize patients as well-aligned vs malaligned. Additionally, three subsets were defined as follows: (1) patients who were malaligned preoperatively (cSVA>=4) and remained well aligned at 1 year postoperatively; (2) patients who were well-aligned but experienced alignment deterioration (cSVA>=4cm) up to 1 year postop, and; (3) patients who never attained cSVA <4cm. These groups were compared in terms of demographic factors, surgical factors, baseline radiographic parameters and radiographic and surgical outcomes at baseline and 1 year, using t-tests and X2 tests for continuous and categorical variables, respectively.
Result(s): A total of 155 patients were included (mean age 61.41, 60.9% F). The entire cohort was analyzed at all time points for alignment using cSVA. Among 89 patients with X-rays at every time point, 30 patients (34%) maintained their good alignment correction at 1-year postop. Seventeen patients (19%) experienced alignment deterioration and 42 patients (46%) never reached cSVA <4cm at any time point. Four patients lost their correction at 3 months, 6 patients at 6 months and 8 patients were malaligned by 1 year. The never-aligned cohort was significantly older when compared to those who maintained alignment or those who deteriorated (65.9 vs 61.8 vs 58.8, p=0.038). Patients who never achieved good alignment and those who suffered deterioration had a significantly higher rate of DJK (42.9% vs 47.1% vs 3.3%, p=0.001). Other failure mechanisms in the deterioration group included loss of subjacent spinopelvic compensation and PJK. At baseline, patients with alignment deterioration had a smaller cSVA compared to those who maintained or never reached good alignment (40.5 vs 52.0 and 60.1mm, p=0.001), and less TK (-43.4 vs -55.9 vs -61.4, p=0.049). At 1-year postop, patients with deterioration had worsening of their mJOA score at 6 months compared to those who maintained or never reached proper alignment (2.50 vs 0.04 vs 1.20, p=0.032). There were no significant differences in smokers, BMI, frailty, osteoporosis, levels fused, UIV, LIV, EBL, operative time, rod diameter, rod material, utilization 3-column osteotomy, mean osteotomy grade, in construct (fused) loss of alignment or revision rate between the groups (all p>.05)
Conclusion(s): Cervical deformity correction surgery failed to achieve acceptable sagittal alignment in 46% of patients. In those with successful correction, 36% suffered alignment deterioration within 1 year. Distal junctional kyphosis was the most common failure mechanism leading to loss of correction. 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: As ASD prevalence increases in our ever-aging population there is a hypothetical concomitant increase in poor bone quality, especially if not recognized and not treated. ASD surgery is expensive and carries a high complication profile. It is important to optimize surgical outcomes and reduce complications especially if modifiable preoperative risk factors can be identified, such as osteoporosis. Additional diagnostic modalities such as a DEXA can add cost, delay diagnosis, and can be an additional insurance hurdle. PURPOSE: Our goal was to examine the utility of HU measurement on preoperative CTs for bone health assessment. STUDY DESIGN/SETTING: Retrospective cross-sectional review of a prospective, multicenter ASD cohort. PATIENT SAMPLE: Surgical ASD patients. OUTCOME MEASURES: Hounsfield Units, history of osteoporosis, DEXA results.
METHOD(S): Operative ASD patients (scoliosis >20, SVA>5cm, PT>25, or TK>60) were included if they had a preoperative CT. HU were measured by each participating site from axial views within the cancellous body (x3: top, middle, bottom) at both L1 and future UIV. Reliability of the measurement between the 3 acquisitions was performed using instar-class correlation for absolute agreement. Association between HU and patient demographics was assess using Pearson's correlation. Finally, correlation between DEXA measurement and HU was conducted to evaluate relationship between bone quality and HU values.
RESULT(S): There were 694/1493 (46%) patients who had a CT including either L1 or UIV. And 521 patients were identified as having both L1 and UIV measurement. Also, 71.8% were female with a mean age of 63years+/-12.5, 52.6% were revision with mean levels fused of 10.5+/-4.5. The intraclass correlation coefficient (ICC) for UIV and L1 were 0.767 (95CI 0.737-0.796]) and 0.802 (95CI [0.774 0.827]), respectively. Previous instrumentation did not affect L1 HU ICC (r=0.798 vs r=0.809) and showed no significant difference in HU value (p=0.232). Comparison of L1 HU between different sites demonstrated no significant difference (p=0.43). Comparison of L1 and UIV did show a significant difference (L1:151+/-77 vs 160+/-62 p<0.001) although there was a significant correlation (r=0.631 p<0.001). The mean HU value at L1 was consistent with previously published values (p=0.542). There were 116 (22.5%) patients who had a DEXA and 97 (18.6%) patients reported a history of osteoporosis. Comparison of DEXA and HU between patients with and without history of osteoporosis showed a significant difference in HU (155+/-76 vs 134+/-79 p<0.001) and but not in DEXA (p=0.07). A significant but weak association between DEXA and HU measurements (r=0.286 & 0.285 p<0.002). HU did not correlate with baseline demographic parameters such as BMI, CCMI, or frailty but did correlate with age (p<0.009 r=-0.215). Similarly, DEXA did not correlate with baseline demographic parameters except for BMI (p<0.002,r=0.298).
CONCLUSION(S): In this large cohort of surgical ASD patients, bone quality assessment was available for 18% of patients via DEXA or 46% via HU on CT. HU measured from an axial image of L1 and UIV appears to be a reliable assessment of bone quality. Previous instrumentation did not alter the measurements. There was a significant but weak correlation when comparing HU to DEXA. Patients with a reported history of osteoporosis had lower HU. 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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OBJECTIVE:Malalignment of the cervical spine can result in cord compression, leading to a myelopathy diagnosis. Whether deformity or myelopathy severity is stronger predictors of surgical outcomes is understudied. METHODS:Surgical cervical deformity (CD) patients with baseline (BL) and up to 1-year data were included. Modified Japanese Orthopaedic Association (mJOA) score categorized BL myelopathy (mJOA = 18 excluded), with moderate myelopathy mJOA being 12 to 17 and severe myelopathy being less than 12. BL deformity severity was categorized using the mismatch between T1 slope and cervical lordosis (TS-CL), with CL being the angle between the lower endplates of C2 and C7. Moderate deformity was TS-CL less than or equal to 25° and severe deformity was greater than 25°. Categorizations were combined into 4 groups: group 1 (G1), severe myelopathy and severe deformity; group 2 (G2), severe myelopathy and moderate deformity; group 3 (G3), moderate myelopathy and moderate deformity; group 4 (G4), moderate myelopathy and severe deformity. Univariate analyses determined whether myelopathy or deformity had greater impact on outcomes. RESULTS:One hundred twenty-eight CD patients were included (mean age, 56.5 years; 46% female; body mass index, 30.4 kg/m2) with a BL mJOA score of 12.8 ± 2.7 and mean TS-CL of 25.9° ± 16.1°. G1 consisted of 11.1% of our CD population, with 21% in G2, 34.6% in G3, and 33.3% in G4. At BL, Neck Disability Index (NDI) was greatest in G2 (p = 0.011). G4 had the lowest EuroQol-5D (EQ-5D) (p < 0.001). Neurologic exam factors were greater in severe myelopathy (p < 0.050). At 1-year, severe deformity met minimum clinically important differences (MCIDs) for NDI more than moderate deformity (p = 0.002). G2 had significantly worse outcomes compared to G4 by 1-year NDI (p = 0.004), EQ-5D (p = 0.028), Numerical Rating Scale neck (p = 0.046), and MCID for NDI (p = 0.001). CONCLUSION/CONCLUSIONS:Addressing severe deformity had increased clinical weight in improving patient-reported outcomes compared to addressing severe myelopathy.

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.

OBJECTIVE/UNASSIGNED:Deterioration of global coronal alignment (GCA) may be associated with worse outcomes after adult spinal deformity (ASD) surgery. The impact of fusion length and upper instrumented vertebra (UIV) selection on patients with this complication is unclear. The authors' objective was to compare outcomes between long sacropelvic fusion with upper-thoracic (UT) UIV and those with lower-thoracic (LT) UIV in patients with worsening GCA ≥ 1 cm. METHODS:This was a retrospective analysis of a prospective multicenter database of consecutive ASD patients. Index operations involved instrumented fusion from sacropelvis to thoracic spine. Global coronal deterioration was defined as worsening GCA ≥ 1 cm from preoperation to 2-year follow-up. RESULTS:Of 875 potentially eligible patients, 560 (64%) had complete 2-year follow-up data, of which 144 (25.7%) demonstrated worse GCA at 2-year postoperative follow-up (35.4% of UT patients vs 64.6% of LT patients). At baseline, UT patients were younger (61.6 ± 9.9 vs 64.5 ± 8.6 years, p = 0.008), a greater percentage of UT patients had osteoporosis (35.3% vs 16.1%, p = 0.009), and UT patients had worse scoliosis (51.9° ± 22.5° vs 32.5° ± 16.3°, p < 0.001). Index operations were comparable, except UT patients had longer fusions (16.4 ± 0.9 vs 9.7 ± 1.2 levels, p < 0.001) and operative duration (8.6 ± 3.2 vs 7.6 ± 3.0 hours, p = 0.023). At 2-year follow-up, global coronal deterioration averaged 2.7 ± 1.4 cm (1.9 to 4.6 cm, p < 0.001), scoliosis improved (39.3° ± 20.8° to 18.0° ± 14.8°, p < 0.001), and sagittal spinopelvic alignment improved significantly in all patients. UT patients maintained smaller positive C7 sagittal vertical axis (2.7 ± 5.7 vs 4.7 ± 5.7 cm, p = 0.014). Postoperative 2-year health-related quality of life (HRQL) significantly improved from baseline for all patients. HRQL comparisons demonstrated that UT patients had worse Scoliosis Research Society-22r (SRS-22r) Activity (3.2 ± 1.0 vs 3.6 ± 0.8, p = 0.040) and SRS-22r Satisfaction (3.9 ± 1.1 vs 4.3 ± 0.8, p = 0.021) scores. Also, fewer UT patients improved by ≥ 1 minimal clinically important difference in numerical rating scale scores for leg pain (41.3% vs 62.7%, p = 0.020). Comparable percentages of UT and LT patients had complications (208 total, including 53 reoperations, 77 major complications, and 78 minor complications), but the percentage of reoperated patients was higher among UT patients (35.3% vs 18.3%, p = 0.023). UT patients had higher reoperation rates of rod fracture (13.7% vs 2.2%, p = 0.006) and pseudarthrosis (7.8% vs 1.1%, p = 0.006) but not proximal junctional kyphosis (9.8% vs 8.6%, p = 0.810). CONCLUSIONS:In ASD patients with worse 2-year GCA after long sacropelvic fusion, UT UIV was associated with worse 2-year HRQL compared with LT UIV. This may suggest that residual global coronal malalignment is clinically less tolerated in ASD patients with longer fusion to the proximal thoracic spine. These results may inform operative planning and improve patient counseling.

OBJECTIVE:Few studies have compared fractional curve correction after long fusion between transforaminal lumbar interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) for adult symptomatic thoracolumbar/lumbar scoliosis (ASLS). The objective of this study was to compare fractional correction, health-related quality of life (HRQL), and complications associated with L4-S1 TLIF versus those of ALIF as an operative treatment of ASLS. METHODS:The authors retrospectively analyzed a prospective multicenter adult spinal deformity database. Inclusion required a fractional curve ≥ 10°, a thoracolumbar/lumbar curve ≥ 30°, index TLIF or ALIF performed at L4-5 and/or L5-S1, and a minimum 2-year follow-up. TLIF and ALIF patients were propensity matched according to the number and type of interbody fusion at L4-S1. RESULTS:Of 135 potentially eligible consecutive patients, 106 (78.5%) achieved the minimum 2-year follow-up (mean ± SD age 60.6 ± 9.3 years, 85% women, 44.3% underwent TLIF, and 55.7% underwent ALIF). Index operations had mean ± SD 12.2 ± 3.6 posterior levels, 86.6% of patients underwent iliac fixation, 67.0% underwent TLIF/ALIF at L4-5, and 84.0% underwent TLIF/ALIF at L5-S1. Compared with TLIF patients, ALIF patients had greater cage height (10.9 ± 2.1 mm for TLIF patients vs 14.5 ± 3.0 mm for ALIF patients, p = 0.001) and lordosis (6.3° ± 1.6° for TLIF patients vs 17.0° ± 9.9° for ALIF patients, p = 0.001) and longer operative duration (6.7 ± 1.5 hours for TLIF patients vs 8.9 ± 2.5 hours for ALIF patients, p < 0.001). In all patients, final alignment improved significantly in terms of the fractional curve (20.2° ± 7.0° to 6.9° ± 5.2°), maximum coronal Cobb angle (55.0° ± 14.8° to 23.9° ± 14.3°), C7 sagittal vertical axis (5.1 ± 6.2 cm to 2.3 ± 5.4 cm), pelvic tilt (24.6° ± 8.1° to 22.7° ± 9.5°), and lumbar lordosis (32.3° ± 18.8° to 51.4° ± 14.1°) (all p < 0.05). Matched analysis demonstrated comparable fractional correction (-13.6° ± 6.7° for TLIF patients vs -13.6° ± 8.1° for ALIF patients, p = 0.982). In all patients, final HRQL improved significantly in terms of Oswestry Disability Index (ODI) score (42.4 ± 16.3 to 24.2 ± 19.9), physical component summary (PCS) score of the 36-item Short-Form Health Survey (32.6 ± 9.3 to 41.3 ± 11.7), and Scoliosis Research Society-22r score (2.9 ± 0.6 to 3.7 ± 0.7) (all p < 0.05). Matched analysis demonstrated worse ODI (30.9 ± 21.1 for TLIF patients vs 17.9 ± 17.1 for ALIF patients, p = 0.017) and PCS (38.3 ± 12.0 for TLIF patients vs 45.3 ± 10.1 for ALIF patients, p = 0.020) scores for TLIF patients at the last follow-up (despite no differences in these parameters at baseline). The rates of total complications were similar (76.6% for TLIF patients vs 71.2% for ALIF patients, p = 0.530), but significantly more TLIF patients had rod fracture (28.6% of TLIF patients vs 7.1% of ALIF patients, p = 0.036). Multiple regression analysis demonstrated that a 1-mm increase in L4-5 TLIF cage height led to a 2.2° reduction in L4 coronal tilt (p = 0.011), and a 1° increase in L5-S1 ALIF cage lordosis led to a 0.4° increase in L5-S1 segmental lordosis (p = 0.045). CONCLUSIONS:Operative treatment of ASLS with L4-S1 TLIF versus ALIF demonstrated comparable mean fractional curve correction (66.7% vs 64.8%), despite use of significantly larger, more lordotic ALIF cages. TLIF cage height had a significant impact on leveling L4 coronal tilt, whereas ALIF cage lordosis had a significant impact on restoration of lumbosacral lordosis. The advantages of TLIF may include reduced operative duration and hospitalization; however, associated HRQL was inferior and more rod fractures were detected in the TLIF patients included in this study.