P94. Preoperative opioid use poorly correlates with mental health in adult spinal deformity: Time to rethink foregone conclusions [Meeting Abstract]
BACKGROUND CONTEXT: Preoperative opioid consumption, poor mental health, and lower socioeconomic status are each associated with worse surgical outcomes for adult spinal deformity (ASD). Little data exits evaluating preoperative morphine milligram equivalent (MME) consumption and preoperative mental health, social function, and socioeconomic status in ASD. PURPOSE: Evaluate the correlations between preoperative daily MME consumption and preoperative depression, anxiety, mental health scores, and socioeconomic status for ASD patients prior to receiving reconstructive ASD surgery. We hypothesized that preoperative MME consumption correlates with preoperative depression, anxiety, poor mental health, poor social function, and poor socioeconomic status in ASD. 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 (SDA) computer adaptive tests (CATs), Area Deprivation Index (ADI) scores.
METHOD(S): From 2018-2020, ASD patients were prospectively enrolled into a multicenter study. Preoperative MME was calculated. Preoperative PROMIS-DEP, PROMIS-ANX, PROMIS=SR, PROMIS-SDA, PROMIS-PI and PF, SRS-22r total and domain scores, and VR-12 mental component summary (MCS) were calculated. ADI scores were collected to assess socioeconomic status, as previously described. MME data were log transformed and two-tailed Pearson correlation coefficients calculated. Correlation strengths were interpreted according to Cohen. Confidence intervals were created with 1,000 sample bootstrapping.
RESULT(S): A total of 207/207 patients enrolled were evaluated; mean age 61 years (18-81). Preoperative opioid consumption was reported in 38% patients (n=78; mean preoperative MME 22.5 mg, range 1-420 mg). Preoperative MME did not correlate with PROMIS-ANX (p=0.07) and did not correlate with socioeconomic status (ADI; p=0.37). Preoperative MME showed small correlations with PROMIS-DEP (r=0.2, p=0.01), VR-12 MCS (r=-.2, p=0.002), and SRS-Mental Health (r=-0.2, p=0.005). Preoperative MME showed moderate correlations with PROMIS-PI (r=0.4, p<0.0001), PROMIS-PF (r=-0.4, p<0.0001), SRS-Pain (r=-0.5, p<0.0001), SRS-Function (r=-0.4, p<0.0001), PROMIS-SR (r=-0.3, p<0.0001) and PROMIS-SSA (r=-0.4, p<0.0001).
CONCLUSION(S): Prospective evaluation of 207 ASD patients demonstrated minimal to no correlations between preoperative MME consumption and preoperative anxiety, depression or low socioeconomic status. Preoperative MME consumption demonstrated moderate correlations with preoperative pain, physical function, and social function scores. The negative impacts of opioid consumption on physical measures are likely independent of psychosocial variables in ASD. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
105. Global coronal decompensation after adult spinal deformity surgery: comparison of upper vs lower thoracic proximal fixation [Meeting Abstract]
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.
212. Matched analysis demonstrates acute rehabilitation or skilled nursing facility care does not reduce readmissions, return to surgery or improve outcomes compared to home discharge following adult spine deformity surgery [Meeting Abstract]
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.
102. How the back affects the neck: preoperative sagittal vertical axis is correlated with cervical myelopathy scores [Meeting Abstract]
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.
188. Prospective analysis of adult spinal deformity patients demonstrates radically different preop demographic, radiographic and quality of life parameters for primary vs revision patients [Meeting Abstract]
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.
177. Would you do it again? Discrepancies between patient and surgeon willingness for adult spine deformity surgery [Meeting Abstract]
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.
39. Optimizing safety in robotic lumbar instrumented fusions: a risk factor analysis of robotic failures [Meeting Abstract]
BACKGROUND CONTEXT: Robot-guided lumbar instrumented fusion (RGLF) has the potential to improve safety and accuracy of pedicle screw placement. However, there are pitfalls in adopting this new technology and, as in adopting any new OR technology, there may be early complications. Optimizing workflow by avoiding interbody placement prior to pedicle screws placement (interbody-first workflow, IFW) and using caution in patients with poor bone quality (L1 Hounsfield units [HU] under 148) may improve outcomes. PURPOSE: To determine risk factors for robot-related complications and suggest optimal OR workflow. STUDY DESIGN/SETTING: Single-center retrospective study. PATIENT SAMPLE: A total of 344 RGLF cases from 2018 to 2021. OUTCOME MEASURES: L1 and UIV HU, levels fused, L5-S1 inclusion, interbody placed first workflow (IFW), hyperlordotic interbody, robot registration method, robot registration failure, intraoperative robot mechanical failures and pedicle screw malpositioning.
METHOD(S): Retrospective analysis of RGLFs at a single institution. Univariate analysis with t-tests, Mann-Whitney U tests, or chi-squared analysis assessed demographics, L1 and UIV HU, levels fused, L5-S1 inclusion, IFW, hyperlordotic cage, and robot registration method as risk factors for robot registration failure, intraoperative robot mechanical failures, and pedicle screw malpositioning. Multivariate logistic regression of risk factors approaching or achieving significance was conducted. A receiver operating characteristic (ROC) curve was created to determine a threshold for independent risk factors.
RESULT(S): A total of 344 RGLFs were included. In registered vs registration failure cases, smoking (12.73% vs 28.57%; p=0.041), L1HU (139.81+/-46.86 vs 177.16+/-55.74; p=0.009), L5-S1 inclusion (50.00% vs 80.95%; p=0.006), and IFW (58.07% vs 85.71%; p=0.014) were significant risk factors on univariate analysis. On multivariate analysis, smoking (p=0.003), L1HU (p=0.006), and L5-S1 inclusion (p=0.022) were independent risk factors and IFW approached significance (p=0.099) for risk of registration failure. In successful vs all robot failures cases, age (55.72+/-13.38 vs 59.92+/-11.38 years; p=0.046), female gender (48.70% vs 69.44%; p=0.018), levels fused (1.37+/-0.63 vs 1.67+/-0.76; p=0.010), L5-S1 inclusion (50.00% vs 69.44%; p=0.027), and IFW (57.47% vs 77.78%; p=0.012) were significant risk factors on univariate analysis. On multivariate analysis, female gender (p=0.047) and L5-S1 inclusion (p=0.049) were independent risk factors and IFW approached significance (p=0.055) for risk of mechanical failure. In successful vs pedicle screw malpositioned cases, IFW was a significant independent risk factor for pedicle screw malpositioning on multivariate analysis (p=0.038). On subanalysis of 124 robot-guided anterior-posterior lumbar fusion (RG APLF), L1 HU was an independent risk factors for registration failure (p=0.007) and approached significance for mechanical failures (p=0.051). ROC analysis revealed a cutoff of L1 HU of 148.55 for mechanical failures (area under the curve = 0.778). Levels fused (1.41+/-0.69 vs 2.00+/-0.54; p=0.018) was a significant risk factor for pedicle screw malpositioning on univariate analysis.
CONCLUSION(S): In all RGLFs, IFW was a risk factor for robot-related complications. In RG APLF, low L1 HU was a risk factor. Robot-related complications may be avoided by placing pedicle screws prior to interbody and by using caution in patients with poor bone quality. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
179. Correcting ASD patients to normative alignment results in no functional benefit but more PJK and PJF [Meeting Abstract]
BACKGROUND CONTEXT: A previous study utilized normative alignment to determine overcorrections and predict mechanical complications in adult spinal deformity (ASD) surgery. Other studies have recommended alignment targets that optimize age-appropriate physical function. The difference in functional outcomes and mechanical complications between these prescribed alignment targets has not been explored. This study utilizes a component angle of the T1 pelvic angle (TPA) within the fusion to compare normative and age-pelvic incidence (PI) optimal alignment in terms of proximal junctional kyphosis (PJK), proximal junctional failure (PJF) and health related quality of life measures (HRQL). Using the component of TPA within the fusion, the T4-pelvic angle (T4PA), allows for the measurement spinopelvic alignment separate from that of the unfused thoracic spine and any PJK that may occur postoperatively. PURPOSE: To compare ASD patients corrected to normative alignment vs age-PI optimal alignment in terms of PJK/PJF and outcomes. STUDY DESIGN/SETTING: Retrospective analysis of a prospective multicenter ASD database and a database of asymptomatic subjects. PATIENT SAMPLE: This study included 1,916 ASD patients and 118 asymptomatic subjects for formula development; 288 ASD patients with 2-year X-ray and HRQL follow-up. OUTCOME MEASURES: SF36-PCS, ODI, SRS-22, NRS back/leg, PJK (change in UIV to UIV+2 >10degree), PJF (defined as severe PJK with change >21.6degree, or UIV olisthesis, or proximal junctional fracture).
METHOD(S): Baseline relationships between age, PI and T4PA, were analyzed in the ASD patients and compared to the asymptomatic subjects. Linear regression modeling was used to determine alignment based on PI and age in asymptomatic subjects (normative alignment), and in ASD patients, alignment corresponding to age-appropriate functional status (optimal alignment). ASD patients with UIV above T4 were grouped based on their corrections: normative vs optimal. Extreme over or under corrected patients were excluded (greater than or less than 2SD from mean postop T4PA). For each group, the rate of PJK and PJF were determined.
RESULT(S): In the multilinear regression analysis of the 119 asymptomatic subjects, T4PA correlated with age and PI, r=.713, p<.0001. 1916 ASD patients were included in the optimal formula development. In the 288 ASD patients included in the pre- to postop analysis (137 normative, 151 optimal), there was no difference in baseline alignment or HRQL between the groups. At 6 weeks, the normative aligned group had smaller T4PA (4.45 vs 14.1) and PI-LL (-7.24 vs 7.4), all p<.0001. Normative aligned patients had the higher PJK rate (40% vs 27.2%, p=.03) compared with optimal; and a higher PJF rate (17% vs 6.8%, p=.008). PJF patients had -1.2degreeof T4PA offset from normative alignment and -5.2degreeof offset from optimal alignment. By contrast, no PJF patients had 3.8degree of T4PA offset from normative alignment and -0.42degree of offset from optimal alignment. There was a trend toward worse 2-year SF36-PCS in patients who suffered PJF (37.7 vs 41.6, p=.09). Both the Normative and Optimal groups improved in outcomes from baseline to 2-year (p<.001) with no difference in 2-year HRQL.
CONCLUSION(S): Correcting ASD patients to normative alignment resulted in higher rates of PJK and PJF without improvements in HRQL. ASD patients should not be corrected to match the alignment of their asymptomatic unfused peers, rather they should be realigned optimally to match age-appropriate physical function. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
267. Establishing safety thresholds for surgical invasiveness based on frailty status in ASD surgery [Meeting Abstract]
BACKGROUND CONTEXT: Both frailty and surgical invasiveness are correlated with increased risk of complications following ASD surgery, yet there is no accepted risk-stratification system combining these factors. PURPOSE: The aim of this study is to ascertain data-driven categories defining the risk for 90-day complications following ASD surgery based on frailty and surgical invasiveness. STUDY DESIGN/SETTING: Retrospective review of a multicenter database. PATIENT SAMPLE: A total of 1,272 surgical ASD patients undergoing spinal fusions >=5 levels OUTCOME MEASURES: Ninety-day complication risk, 90-day complication rate, invasiveness thresholds for increased complications.
METHOD(S): Using a prospective, multicenter database, we identified 1,272 surgical ASD patients undergoing posterior spinal fusion of at least five levels. Patients were separated into three frailty groups based on the ASD-FI frailty index. Within each frailty group, stratum-specific likelihood ratio (SSLR) analyses were performed to define frailty-based surgical invasiveness cutoffs associated with increased risk for 90-day complications. Cutoffs generated through SSLR were confirmed with multivariable logistic regression analysis controlling for age, alignment, and ODI.
RESULT(S): Mean age was 60 +/- 14 years, 74% females. Of 1,272 surgical ASD patients, 319 (35%) were nonfrail (NF), 667 (52%) frail (F), and 286 (23%) severely frail (SF). Mean SI was 93 +/- 35. The mean complication rate was 35.4% for NF, 37% for F and 43.6% for SF. SSLR analysis of NF patients produced 2 complication categories: 33% complication rate for SI < 153 and 73% for SI >= 153. NF patients with SI >= 153 had 4.14x higher odds of complications than NF patients with SI <153 (p=0.04). SSLR analysis of F patients produced 3 complication categories: 26% complication rate for SI < 60, 42% for SI of 60 to 179, and 64% for SI >= 180. Relative to F patients with SI < 60, F patients with SI 60 to 179, and SI >= 180 had 2.4x and 6.7x higher odds of complications, respectively (p<0.01 for both). SSLR analysis of SF patients produced 2 complication categories: 35% complication rate for SI < 82 and 49% complication rate for SI >= 82. SF patients with SI >= 82 had 1.77x higher odds of complications than SF patients with SI < 82 (p=0.04).
CONCLUSION(S): Frailer groups were found to have lower SI cutoffs, indicating the less invasiveness surgeries can be performed on frail patients to minimize complication risk. This risk-stratification system is useful for counselling patients regarding their risk of complication. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
127. Durability and failure mechanisms of cervical deformity correction surgery [Meeting Abstract]
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.