Faculty Bibliography

BACKGROUND CONTEXT: 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 for patients with this complication is unclear. PURPOSE: Our objective was to compare outcomes for long sacropelvic fusions with upper-thoracic (UT) vs lower-thoracic (LT) UIV in patients with worsening GCA>=1cm. STUDY DESIGN/SETTING: Retrospective review of a prospectively collected multicenter 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 alignment, HRQL (Oswestry Disability Index [ODI], Short Form-36 [SF-36], Scoliosis Research Society-22 [SRS-22r], numerical rating scale [NRS] back/leg pain scores), and complications.
Method(s): This is 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>=1cm from preoperative to 2-year follow-up.
Result(s): 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 postop (UT 35.4%, LT 64.6%). At baseline, UT had younger age (61.6+/-9.9 vs 64.5+/-8.6years, p=0.008), more osteoporosis (35.3% vs 16.1%, p=0.009), and worse scoliosis (51.9+/-22.5degree vs 32.5+/-16.3degree, p<0.001). Index operations were comparable except UT 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+/-3.0hrs, p=0.023). At 2-year follow-up, global coronal deterioration averaged 2.7+/-1.4cm (1.9 to 4.6cm, p<0.001), scoliosis improved (39.3+/-20.8degree to 18.0+/-14.8degree, p<0.001), and sagittal spinopelvic alignment improved significantly for all patients. UT maintained smaller positive C7-sagittal vertical axis (SVA) (2.7+/-5.7 vs 4.7+/-5.7cm, p=0.014). Postoperative 2-year health-related quality-of-life (HRQL) was significantly improved from baseline for all patients. Significant HRQL comparisons included: UT had worse 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). Also, fewer UT patients improved by >=1 minimal clinically important difference in leg pain NRS (41.3% vs 62.7%, p=0.020). Total reported complications (total=208, reoperation=53/major=77/minor=78) had comparable percentages of affected UT vs LT patients, but the percentage of re-operated patients was higher for UT (35.3% vs 18.3%, p=0.023). UT had higher reoperation rates for rod fracture (13.7% vs 2.2%, p=0.006), pseudarthrosis (7.8% vs 1.1%, p=0.006), but not proximal junctional kyphosis (9.8% vs 8.6%, p=0.810).
Conclusion(s): In ASD patients with worse 2-year GCA after long sacropelvic fusion, upper-thoracic UIV was associated with worse 2-year HRQL compared to lower-thoracic UIV. This may suggest residual global coronal malalignment is clinically less tolerated in ASD patients with longer fusions to proximal thoracic spine. These results can inform operative planning and improve patient counseling. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Concerns exist regarding disease transmission and cost associated with postoperative nonroutine discharge. Few data exist evaluating impact of nonroutine vs home discharge on readmissions, complications and patient reported outcome measures (PROMs) for adult spinal deformity (ASD) surgery. PURPOSE: Evaluate 30-day readmissions, 90-day return to surgery, postoperative complications, and postoperative PROMs for matched ASD patients receiving nonroutine discharge vs home discharge following surgery. 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), duration of hospital stay, 30-day readmission, 90-day return to surgery, postoperative complications.
METHOD(S): Surgically treated ASD patients prospectively enrolled in a multicenter ASD study were divided into two discharge disposition groups, nonroutine (NON) and home (HOME). NON was further divided into acute rehab (REHAB) or skilled nursing facility (SNF) discharge. Study inclusion criteria; (1) surgery >=5 levels fused, (2) >=2-year follow-up. PSM was used to match NON vs HOME for age, frailty and total levels fused. 30-day hospital readmission, 90-day return to surgery, postoperative complications, one and minimum 2 year PROM data was compared for NON vs HOME, and REHAB vs SNF vs HOME.
RESULT(S): From 2015 to 2019, 241 of 374 eligible treated patients were evaluated and 158 included in this study after PSM (mean 2.7 year follow-up). NON (n=106) and HOME (n=52) had similar age (67.6 vs 67.6 years), ASD-frailty index (3.9 vs 3.9), levels fused at surgery (13.8 vs 13.7), and preop PROMs, respectively (p>0.05). Duration of hospital stay (9.7 vs 10.4 days), 30-day readmission (6.6% vs 6.6%), 90-day return to surgery (9.4% vs10.4%), total complications/patient (2.0 vs 1.5), major complications/patient (0.8 vs 0.5), were similar NON vs HOME, respectively (p>0.05). At last follow-up, HOME demonstrated better ODI (21.6 vs 28.2), SRS-total (3.8 vs 3.5), and SRS-activity (3.7 vs 3.3) than NON, respectively (p<0.05). Sub-analysis of REHAB (N=63) vs SNF (N=41) vs HOME showed similar findings, including similar 30-day readmissions, 90-day return to surgery, and complications (p>0.05) and improved PROMs for HOME vs REHAB and SNF (p<0.05).
CONCLUSION(S): Analysis of 158 operatively treated ASD patients prospectively enrolled into a multicenter study and matched for age, frailty, and surgery performed demonstrated that postoperative discharge to skilled nursing or acute rehab facilities did not reduce 30-day readmissions, 90-day return to surgery, or postoperative complications. At one and minimum two years postop, patients discharged home had better PROMs scores than nonroutine discharge. These data should be considered in conjunction with postoperative needs and the cost and disease transmission risks for nonroutine discharge. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Both regional cervical and thoracolumbar/spinopelvic (TL) sagittal alignment have been shown to correlate with health-related quality of life (HRQOL). Recently it has been demonstrated that cervical sagittal alignment is associated with HRQOL in patients with TL deformity. It remains unknown if TL alignment parameters are related to cervical HRQOL and complication rates for patients with cervical deformity. PURPOSE: To examine the relationship between cervical and thoracolumbar alignment parameters with HRQOL among patients with adult cervical deformity (CD).
Study Design/Setting: : Retrospective cohort study of a prospective multicenter adult CD database. PATIENT SAMPLE: A total of 119 CD patients. OUTCOME MEASURES: HRQOL (Neck disability Index, NDI, Modified Japanese Orthopaedic Association score, mJOA, EuroQol-5 dimension, EQ5D), radiographic alignment (cervical lordosis, cervical sagittal vertical axis [SVA], T1 slope, T1 slope-cervical lordosis, maximum TL coronal Cobb angle, C7 coronal plumb line, C7-S1 SVA, pelvic tilt [PT], mismatch between pelvic incidence [PI] and lumbar lordosis [LL]), and complications.
Method(s): : Adult (>=18 years old) CD patients (cervical kyphosis >10degree, coronal scoliosis >10degree, cSVA >4cm, TS-CL >10degree, or CBVA >25degree) with min 1-year follow-up. HRQOL and postop complications (any, major, minor, and distal junctional kyphosis [DJK]) were compared between CD patients with preop TL deformity [+TLD] (C7-S1 SVA >5cm and/or PI-LL>10degree) and those without [-TLD]. TL radiographic parameters were correlated with cervical HRQOL.
Result(s): : The mean age was 61.6+/-10.1 years and there were 50 (42.0%) +TLD patients. +TLD patients had statistically similar HRQOL for all metrics at preop, 1 year, and 2 years postop compared with -TLD (p>0.05). However, patients with preop SVA>5cm (n=21, 17.6%) had a significantly worse preop mJOA (11.6+/-2.2 vs 14.2+/-2.3, p<0.0001) and NDI (55.7+/-15.8 vs 44+/-14.8, p=0.03) scores compared to patients with normal preop SVA. Preop SVA directly correlated with preop NDI (r=0.39, p=0.005) and inversely with mJOA (r=-0.46, p=0.001). There were no significant postop correlations between baseline radiographic TL parameters and postop cervical HRQOL (p>0.05). The mean number of fusion levels for +TLD was not statistically different to -TLD patients (8.5+/-2.2 vs 8.5 +/- 3.9, p>0.05) and for the rates of pedicle subtraction osteotomy and vertebral column resection (13.1% vs 12.0%, p>0.05 and 2.6% vs 4.0%, p>0.05, respectively). Postop complication rates were statistically similar between +TLD and -TLD groups for any complication (60% vs 67%, p=0.45), major (20% vs 16%, p=0.56), minor (26% vs 35%p=0.30), and specifically DJK (8% vs 10%, p=0.69).
Conclusion(s): : The incidence of concomitant thoracolumbar deformity in adult cervical deformity patients is 42.0%. +TLD patients have worse preop NDI and mJOA scores. However, this difference is no longer apparent postoperatively. +TLD patients did not have a longer posterior fusion construct nor an increase in 3-column osteotomies. In addition, the complication rates and risk for postop DJK are similar. Although there is a strong association with how the neck affects the back, the converse has less of a relationship. This study provides important information regarding this unique population of adult cervical deformity patients that can help guide clinical decision-making. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: ASD is a vague and heterogeneous label applied to adults afflicted with varying types, severities, and etiologies of spine deformities. We hypothesized that ASD patients with a history of spine fusion and associated spine deformity (revision=R) have distinct pathognomonic differences from ASD patients with no history of spine fusion (primary=P). PURPOSE: Evaluate baseline differences for revision vs primary ASD patients including demographics, radiographic spine deformity, functional measures, opiate consumption and patient-reported outcome measures (PROMs), prior to receiving reconstructive ASD surgery. STUDY DESIGN/SETTING: Preoperative analysis of ASD patients prospectively enrolled into a multicenter study. PATIENT SAMPLE: ASD patients prospectively enrolled into multicenter study. OUTCOME MEASURES: Numeric rating scale (NRS) back and leg pain, Scoliosis Research Society-22r questionnaire (SRS-22r), Edmonton Frailty Index (EFI score), grip strength, Veterans Rand Health Questionnaire (VR-12), Oswestry Disability Index (ODI), daily morphine milligram equivalent consumption (MME), PROMIS-Pain Interference (PROMIS-PI), PROMIS-Physical Function (PROMIS-PF), PROMIS-Depression (DEP), PROMIS-Anxiety (ANX), PROMIS-Satisfaction with Social Roles (SR) and PROMIS-Satisfaction with Discretionary Social Activities (SSA) computer adaptive tests (CATs).
METHOD(S): From 2018-2020, patients age >18 years were enrolled in a multicenter prospective study evaluating surgical treatment for ASD. Patients were dichotomized according to R vs P, and preop demographics, grip strength, frailty, daily MME consumption, physical examination, radiographic measures, and PROMs data were compared.
RESULT(S): A total of 204/204 enrolled patients were evaluated; R (n=99), P (n= 105). R and P had similar age, Charleson Comorbidity Index (CCI) and gender distribution (p>0.05). R had greater daily MME consumption (35mg vs 15mg), were more frail (EFI score 4 vs 2), and had greater incidence of motor deficits (54% vs 37%) than P, respectively (p<0.05). R differed radiographically from P in 11/15 measurements, as nearly all sagittal parameters were worse for R (SVA=139mm vs 57mm; PI-LL=26degree vs 12degree; PT= 28.2degree vs 20.7degree), while P had greater scoliosis (50.6degree vs 20.3degree), respectively (p<0.05). Nearly all PROM measures were worse for R vs P, including disability (ODI=48 vs 38), pain measures (PROMIS PI=66.9 vs 61.9; NRS-Back=7.0 vs 6.0), physical function (PROMIS-PF=32.8 vs 36.8, SRS-Activity=2.6 vs 3.2), social function (PROMIS-SSA= 40.4 vs 45.4), depression (PROMIS-DEP=51.1 vs 48.8), and self-image (SRS-Appearance=2.2 vs 2.6).
CONCLUSION(S): Revision ASD patients are distinctly different from primary ASD patients. Despite having similar preop age, gender and CCI, R were more frail, consumed more opiates, and reported greater pain, disability, function, and worse mental health than P. R had greater sagittal deformities while P had worse coronal deformities. Future analysis of ASD patients should distinguish between revision and primary patients to avoid confounding analyses. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: ASD surgery is associated with postoperative improvements in patient pain and function but is also associated with high complication rates and long recovery. Accordingly, if given a choice, patients may indicate they would not undergo surgery again. PURPOSE: At minimum two years postop, evaluate 1) surgically treated ASD patients for willingness to receive/not receive the same surgery, 2) surgeon willingness to perform/not perform the same surgery, 3) surgeon opinion if the corresponding patient would indicate they would/would not have the same surgery again. STUDY DESIGN/SETTING: Analysis of patient vs surgeon willingness to perform/receive surgery for ASD patients enrolled into a prospective, 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, patient and surgeon willingness to perform surgery.
Method(s): Surgically treated ASD patients, prospectively enrolled into a multicenter study from 2009-2018, were asked at minimum 2 years postop, using SRS-22r question 22 if, based upon their surgical and recovery experience, they would undergo the same surgery. Surgeons were matched to their corresponding patients and the surgeons asked if 1) surgeon would perform the same surgery on the patient and why/why not, 2) surgeon believed the patient would undergo the same surgery and why/why not. Patients were divided into those that indicated they would (yes) or not (no) have same surgery. Agreement between patient and surgeon willingness for same surgery was assessed and correlations between willingness for same surgery and postop complications, deformity improvement, and PROMs evaluated.
Result(s): Of 961 patients eligible for study, 580 were evaluated. The no group (n=108, 18.6%) had similar levels fused, osteotomies, duration of hospital and SICU stay, and major complications as the yes group. (n=472; 81.4%; p>0.05). No group members were younger (58.5 vs 61.6 years), more frail (ASD frailty scale 3.9 vs 3.3), and at minimum 2-years postop had more complications requiring surgery and worse postop improvements for all PROMs including ODI (3.8 vs 18.9), SF-36 PCS (1.8 vs 10) and SRS-22r total (0.4 vs 0.9), pain (0.5 vs 1.2), activity (0.2 vs0.7), and self-image (0.6 vs 1.3) than the yes group, respectively (p<0.05). MCID was reached in 28-56% of no group vs 62- 81% of yes group. Patient willingness to receive surgery varied by surgical institution (70% to 89%; p<0.05). Surgeons accurately identified yes group (91%) but poorly identified the no group (22%; p<0.05).
Conclusion(s): ASD patient willingness to undergo same surgery is important for counseling. Unwillingness for same surgery was associated with PROMs, MCID and complications requiring surgery. Surgeons were poorly able to identify patients unwilling to undergo the same surgery. More research is needed to understand patient experiences recovering from ASD surgeries. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: ASD is a complex pathology that benefits greatly from surgical treatment despite being associated with high rates of complications. Despite continuous innovation, little is known regarding the association between changes in surgical techniques and complications. PURPOSE: To investigate the evolution of patient profiles and surgical complications across a single prospective multicenter database. STUDY DESIGN/SETTING: Retrospective review of prospective data. PATIENT SAMPLE: This study included 947 adult spinal deformity patients surgically treated between 2008 and 2018. OUTCOME MEASURES: Complication types and rates.
METHOD(S): Surgical ASD patients (TK >60degree, SVA >5cm, PT >25degree or Cobb angle >20degree) with minimum 2-year follow-up were included and stratified into 3 equal groups by date of surgery. Demographic, preoperative data, surgical information, and complications were compared across time using a moving average of 316 patients to delineate those enrolled at the beginning of the study (Early) from the most recent one (Late).
RESULT(S): Among the total, 947/1260 (67%) patients completed their 2-year follow-up with an enrollment rate of 7.7+/-4.1 patients per month. Compared to the Early phase (Oct 2008 and Nov 2012), patients enrolled more recently (Jan 2016 to Jan 2018) were older (Age: 56.7+/-15yovs 64.3+/-12.3), sicker (CCI: 1.46+/-1.6 vs 2.08+/-1.78), more disabled (ODI: 42.6+/-19.4 vs 45.7+/-15.3; PCS: 32.8+/-10.4 vs 29.7+/-8.5), with more pronounced sagittal deformity (SRS-Schwab type N: 26.3% vs 50.9%: PI-LL modifier ++: 37.1% vs 46.8%) (all p<0.05). Changes in surgical treatment included an increase use of IBF (61% vs 69.9%), more ACR/3CO use (21% vs 37%) and a decrease in 3CO rate (21% vs 12%), shorter fusion (11.2+/-4 vs 9.8+/-5), more supplemental rods (0.3% vs 26.9%) and BMP use (64.1% vs 80.1%) (all p<0.05), but no significant difference in invasiveness (91.2+/-37.1 vs 86.0+/-36.9 p=0.06). LOS decrease by 1 day, EBL by 500 cc and rate of ICU stay decrease from 71% to 53% (all p <0.001). There was no significant difference in overall complication rate (73% vs 67.4% p=0.14) despite a significant decrease in major complications requiring a reoperation (27.6% vs17.4% p=0.002) driven by a decrease in implant (8.3% vs 4.1% p=0.032) and radiographic failures (12.7% vs 5.7% p=0.002). Rate of major operative complication decreased (11.8% vs 6.7% p=0.028) while rate of major radiographic complication increased (0.6% vs 5.7% p<0.001) leading to a stable rate of major complications without reoperation (28.3% vs 27.9% p=0.92). No significant difference in minor complication rate (38.7% vs 34.2% p=0.24) The moving average analysis revealed a steady decrease in major complications associated to a reoperation (from 28% to 17%). The lowest peak of major complications (21%) occurred between Feb 2014 and Oct 2016, and the lowest overall complication rate (62%) occurred between July 2014 and Feb 2017.
CONCLUSION(S): Despite an increase in patient complexity including older, more medical morbidities and larger deformities, complication rates did not increase and the rate of complications requiring surgery decreased over time. These findings likely reflect evolutions in practice improvement including use of supplemental rods, PJK prophylaxis, BMP use, and targeting age-appropriate deformity corrections. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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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 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: 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: 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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