Faculty Bibliography

BACKGROUND CONTEXT: T1 slope (T1S) is a parameter typically discussed in the context of cervical deformity and is correlated with health-related quality of life outcomes. Although prior research has suggested that T1S is related to global alignment, a definition for "high" T1S has not been established. Most patients undergoing cervical surgery do not receive full spine imaging. Therefore, it would be beneficial to have a parameter obtained from cervical radiographs that is associated with thoracolumbar malalignment. PURPOSE: To define a threshold for T1S that is associated with thoracolumbar malalignment STUDY DESIGN/SETTING: Retrospective review of a prospective adult spinal deformity(ASD) database PATIENT SAMPLE: A total of 226 preoperative ASD patients. OUTCOME MEASURES: Baseline sagittal alignment: T1S, thoracic kyphosis(TK), C7 sagittal vertical axis (SVA), T1 pelvic angle (TPA), pelvic tilt (PT), pelvic incidence-lumbar lordosis mismatch (PI-LL).
METHOD(S): A database of preoperative ASD patients was analyzed. Patients without preoperative full-spine images were excluded. Measures obtained from standing lateral radiographs included: T1S, TK, SVA, TPA, PT, and PI-LL. T1S was correlated to each of these parameters. Decision tree analysis was then used to determine the T1S corresponding to published thresholds for high TK (40degree), SVA (40mm), TPA (25degree), and PT (25.degree). Alignment between high and normal T1S patients was compared via t-tests and chi-square tests.
RESULT(S): A total of 226 preoperative ASD patients were included (mean 58+/-16y 62% F). At baseline, 30% had high TK, 54% had high SVA, 46% had high TPA, and 46% had high PT. Larger T1S was significantly correlated with greater SVA (R=.365) TPA (R=.302), TK (R=.606), and PT (R=.230)(all p<.001). Decision tree analysis yielded a threshold of 30degree for high T1S, which 50% of patients had. Compared to patients with T1S<30degree, those with T1S>30degree had higher TK (41.5degree vs 25.8degree), SVA (78.7mm vs 33.7mm), TPA (27.6degree vs 18.3degree), and PT (26.3degree vs 20.8degree), and PI-LL (18.2degree vs 11.7degree)(all p<0.05). Seventy-nine percent of patients with high T1S had high TK (T1S<30= 13%), 69% had high SVA (T1S<30=38%), 66% had high TPA (T1S<30= 37%), 60% had PT>25degree (T1S<30= 42%), and 47% had PI-LL>20degree (T1S<30= 34%) (all p<.05). T1S was not associated with PI.
CONCLUSION(S): Similar to previous studies higher T1S was associated with worse global alignment. T1S was most strongly associated with TK. A T1S=30degree corresponds to thresholds for high TK, SVA, TPA, and PT. Therefore, surgeons should consider obtaining full-spine radiographs if a T1S>30degree is present on cervical imaging. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Sagittal malalignment has been discussed extensively in adult spinal deformity (ASD) literature, while coronal malalignment (CM) and fractional curve (FC) have received less attention. As a result, little guidance currently exists for surgical indications in managing CM, despite it being a relatively common occurrence that can considerably impact patient wellbeing. Patients with CM significantly affected by FC are at particular risk for continued CM postoperatively, along with its complications. PURPOSE: Assess types of approach to fusion of the fractional curve in ASD surgery and their relation to coronal alignment and sagittal alignment. STUDY DESIGN/SETTING: Retrospective review at single institution. PATIENT SAMPLE: A total of 82 ASD patients undergoing primary spinal fusion of 4 or more levels to sacrum or pelvis. OUTCOME MEASURES: Baseline (BL), 1-year (Y1) postoperatively and BL-Y1 difference (DELTABL-Y1) in magnitudes of FC, coronal alignment (CA) and sagittal alignment (SA) parameters: pelvic incidence-LL (PI-LL), cervical sagittal vertical axis (cSVA), T1 pelvic angle (TPA).
METHOD(S): Patients >=18 years old undergoing primary >=4-level fusion to sacrum/pelvis between October 2011 and January 2018 with minimum 6-month follow-up included. Chart review performed for operative dates and details and patient follow-up information. Coronal and sagittal parameters measured using deformity measuring software program. FC measured as segmental angle between L4 and S1. CA measured as distance between C7 plumb line and central sacral vertical line. CA>=20mm designated as CM, per guidelines in literature. Chi-squared test used to compare percentages and ANOVA used to compare means, with significance set at p<0.05.
RESULT(S): A total of 82 patients studied (68.3%F, age 62.6+/-13.3, BMI 28.1+/-6.6, Charlson comorbidity index 0.80+/-1.16). Nine patients (10.98%) had anterior-posterior fusion (AP), 41 (50%) posterior-only fusion with interbody device (PIB), 32 (39.02%) PSF without interbody (PSF). Twenty-three patients (28.04%) had FC>=15degree at BL, 7 (8.54%) at Y1. Forty-one patients (50%) had CM at BL, 35 (42.68%) at Y1. AP fusion patients had least levels fused (6.4 AP, 11.4 PIB, 11.8 PSF, p<0.001). No difference in revision by approach (55.56% AP, 24.39% PIB, 28.13% PSF, p=0.179). Approach type was not associated with different BL, Y1 or DELTABL-Y1 alignment parameters for FC, CA or SA. Mean FC 9.89degree at BL, 6.91degree at Y1 and DELTABL-Y1 difference 5.77degree, no difference between approach groups (p=0.361, 0.127, 0.550, respectively). Mean value for CA 33.62mm at BL, 21.15mm at Y1 and DELTABL-Y1 difference 23.23mm, no difference between approach groups (p=0.087, 0.153, 0.206, respectively). Mean PI-LL 25.21degree at BL, 11.1degree at Y1 and DELTABL-Y1 difference -13.7degree, no difference between approach groups (p=0.503, 0.600, 0.356, respectively). Mean cSVA 27.53degree at BL, 28.85degree at Y1 and DELTABL-Y1 difference 1.29degree, no difference between approach groups (p=0.364, 0.099, 0.141, respectively). Mean TPA 28.37degree at BL, 21.12degree at Y1 and DELTABL-Y1 difference -6.63degree, no difference between approach groups (p=0.066, 0.248, 0.138, respectively).
CONCLUSION(S): Fusion to the sacrum/pelvis improves sagittal alignment, fractional curve and coronal alignment in most patients. However, while fractional curve and sagittal alignment are better corrected, coronal malalignment, particularly more severe malalignment at baseline, tends to persist postoperatively. Type of approach and use of interbody device does not appear to significantly impact these results. This should be considered in preoperative planning for patients with coronal deformity. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Existing health outcome (HRQL) metrics do not adequately capture disability from cervical deformity (CD) and do not correlate with cervical malalignment. In the novel Patient Generated Index (PGI) patients report their greatest difficulties related to their CD. These results were used to determine items that should be included in a CD-specific HRQL. PURPOSE: To utilize the PGI to reveal the aspects of CD disability not captured by existing HRQLs. STUDY DESIGN/SETTING: Retrospective review of a prospective CD database. PATIENT SAMPLE: A total of 45 CD patients. OUTCOME MEASURES: HRQL metrics: PGI, NDI, mJOA, EQ-5D.
METHOD(S): CD patients completed the PGI by describing aspects of their disability that bother them the most. The responses were weighted and scored. PGI responses were categorized into domains: Sagittal discomfort/range of motion (ROM), Activities of Daily Living (ADL), and Social Life/Hobbies. PGI scores and legacy HRQL metrics were correlated with alignment, pain, age, sex, BMI, and medical comorbidities. R2 values are reported for linear regression models that include the drivers significantly associated with each HRQL metric.
RESULT(S): Forty-five CD patients (mean cSVA: 51mm) including 12 PGI patients (mean cSVA: 62mm) were included for analysis. PGI scores were found to be driven significantly by age and C2 Slope (r2=0.50). NDI was driven significantly by neck pain, back pain, and BMI (r2=0.32). mJOA was driven significantly by Charlson Comorbidity Score, back pain and weight (r2=0.33). EQ5D was significantly driven by CBVA, age and T1 Slope (r2=0.78). When examining PGI domains, Sagittal Discomfort/ROM score was driven significantly by cSVA and age (r2=0.54). ADL score was driven by CBVA and a medical history of neuromuscular disease (r2=0.87). Social Life/Hobbies score was driven by Charlson Comorbidity Scores, a medical history of ankylosing spondylitis, and a medical history of connective tissue disease (r2=1.0). Horizontal Gaze/Walking Safety, Pain, and Neurologic Complaints did not correlate significantly with alignment, pain, demographic info or past medical history.
CONCLUSION(S): Legacy HRQLs do not adequately capture CD disability and do not correlate with cervical malalignment. In a CD cohort, PGI scores and EQ5D scores were driven significantly by sagittal alignment. However, mJOA and NDI were driven by pain and medical comorbidities. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Cerebral palsy (CP) can be described as a "static encephalopathy with progressive musculoskeletal pathology." Nonambulant children (GMFCS IV&V) have high rates of both spastic hip disease and neuromuscular scoliosis. Adult sagittal spinal deformity correction is known to cause acetabular retroversion and reduced pelvic tilt, resulting in increased rates of prosthetic hip dislocation; however, the role of spinal alignment on hip status in CP remains unknown. PURPOSE: To identify surgical factors and postoperative spinal alignment parameters that are associated with worsening postoperative hip status (WHS) (ie, subluxation, dislocation or resection) after spinal fusion. STUDY DESIGN/SETTING: Prospective multicenter outcomes study of nonambulant CP patients (GMFCS IV&V) requiring spinal fusion. PATIENT SAMPLE: A total of 142 operative CP patients with preoperative, 6-week, 1Y, 2Y and 5Y postoperative follow-up. OUTCOME MEASURES: Postoperative spinal alignment parameters associations with WHS up to 5Y postoperatively.
METHOD(S): WHS was defined by permutations of baseline and 1Y, 2Y and 5Y hip status of left and right hips by a change from either a normal hip at baseline (BL) that became subluxated, dislocated or resected at postop intervals; or if a subluxated hip at BL became dislocated or resected at postop intervals. Hip status up to 5Y postop was analyzed according to age, sex, coronal spinal alignment (major curve Cobb, pelvic obliquity), sagittal spinal alignment (thoracic kyphosis, T12-S1 lumbar lordosis, C7-S1 sagittal vertical axis), Risser score, hip position at rest, upper and lower- instrumented vertebrae (UIV&LIV), levels fused and fusion to the sacrum. Potential cutoff values for alignment parameters at which the relationship with hip status was determined using receiver operating characteristic (ROC) curves. Logistic regression was used to determine odds ratios for predictors of WHS.
RESULT(S): Of 142 patients (mean age 13.7+/-2.5, 48.3% female), 36 (25.4%) had WHS postoperatively. 7 had reoperation of their spinal fusion, 3 for loose screws/bolts and 4 for prominent instrumentation. ROC curve analysis and multivariate logistic regression demonstrated that the only spino-pelvic alignment parameter that significantly correlated with WHS was lumbar hyperlordosis (T12-L5) >60degree (p=.015), OR=2.61 (CI 1.19-5.75). Assessment of all patients demonstrated an increase in pre- to postop LL. Change in LL pre- to postoperative was no different between groups (p=.643), however the WHS group was more lordotic at baseline and postop (pre 44degree, post 58degree) compared to the no change group (pre 36degree, post 50degree). Age at surgery (p=0.214), sex (p=0.955), Risser score (p=0.205), major coronal cobb angle (p=0.907), thoracic kyphosis (p=0.717), global sagittal alignment (C7-S1 SVA p=0.320), levels fused (p=0.064), fusion to the sacrum (p=.548), coronal pelvic obliquity (p=0.652), or hip position at rest (adducted/abducted/neutral; p=.284) were not associated with WHS. Reoperation was not associated with WHS (p=.304).
CONCLUSION(S): Postoperative hyperlordosis (>60degree) is the only determined risk for WHS at 5Y after spinal fusion in nonambulant patients with cerebral palsy (GMFCS IV&V). WHS likely relates to anterior pelvic tilt and functional acetabular retroversion due to hyperlordosis, as well as loss of protective lumbo-pelvic motion causing anterior femoracetabular impingement. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: The Patient-Reported Outcomes Measurement Information System (PROMIS) is a comprehensive self-report measurement tool with patient functions, symptoms, behaviors, and mental health outcomes. Little work has been done correlating PROMIS physical health domain metrics with established adult spinal deformity (ASD) classifications such as SRS-Schwab. PURPOSE: To correlate sagittal alignment components via the SRS-Schwab classification system with established PROMIS domains in a cohort of ASD patients. STUDY DESIGN/SETTING: Retrospective review of a single-center stereoradiographic database. PATIENT SAMPLE: A total of 41 ASD patients with complete baseline radiographic and PROMIS data. OUTCOME MEASURES: PROMIS physical health domain metrics (Pain Intensity [PI], Physical Function [PF], Pain Interference [Interference]), SRS-Schwab modifiers (SVA, PI-LL, PT) METHODS: Surgical ASD patients (SVA>=5cm, PT>=25degree or TK >=60degree) >=18 years old with available baseline (BL) radiographic and PROMIS data were isolated in the single-center comprehensive Spine Quality Database (Quality). Patients were classified according to SRS-Schwab deformity modifiers(0,+,++) for SVA, PI-LL and PT. Descriptives and univariate analyses compared population-weighted PROMIS scores for PI, PF and Interference across ASD deformity modifiers. Conditional Tree Analysis (CTA) with logistic regression sampling established cut-off points for PROMIS scores predicting severe malalignment (++) at BL compared to mild or moderate (0,+).
RESULT(S): A total of 41 patients (58.95 yrs,75.6%F,29.1kg/m2) met inclusion criteria. BL SRS modifiers were as follows: SVA 51.2%, 2.4%, 46.3% (0,+,++); PI-LL 27.3%, 12.1%, 60.6%(0,+,++); PT 18.2%, 36.4%, 45.5% (0,+,++). Mean cohort PI score was 94.2+/-6.0, mean PF score 8.95+/-10.1, mean Inter score 57.84+/-5.46. PF and Interference differed significantly across low and high SVA groups, with low SVA having significantly higher PF (13.50 vs 3.68,p<0.001) and lower Inter (59.62 vs 56.30, p=0.05). PI did not differ across SVA groups (p>0.05). Low PI-LL pts had significantly higher PF than pts with ++PI-LL (19.3 vs 4.15,p=0.001) and trended lower PI and Inter without significance. No significant differences in PI, PF or Inter were found across PT groups (all p>0.05). CTA found a PI score>98 or PF score <6 were independent predictors of Severe (++) SVA as opposed to Mild/Moderate SVA. For example, a PF score<6 increased odds of ++SVA by at least 2.7x compared to 0/+SVA. Similarly, significant thresholds for PI (>98) and PF (<8) scores were found for ++PI-LL, but not ++PT (p>0.05). Pain Interference did not predict SRS metrics to a significant degree (all p>0.05).
CONCLUSION(S): Inferior PROMIS scores of pain intensity and physical function predicted increasingly severe SRS sagittal modifiers at baseline, specifically severe sagittal vertical axis and lumbopelvic mismatch. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: The Adult Spinal Deformity Frailty Index (ASD-FI), a validated modality for quantifying frailty, stratifies patients into categories not frail (NF), frail (F) and severely frail (SF). However, the cost of treating each frailty state is unknown. PURPOSE: Investigate the cost utility of treating not frail versus frail or severely frail ASD patients. STUDY DESIGN/SETTING: Retrospective review of a prospective single center adult spinal deformity database. PATIENT SAMPLE: A total of 79 operative and non operative ASD patients >=18 years old, with baseline and 2Y ASD-FI and Oswestry Disability Index (ODI) scores. OUTCOME MEASURES: ODI, SF-6D, Cost per quality adjusted life years (QALY), Incremental Cost Effectiveness, Ratio (ICER).
METHOD(S): Inclusion criteria was surgical ASD (scoliosis>=20degree, SVA>=5cm, PT>=25degree, or thoracic kyphosis >=60degree) patients >18 years with available frailty and ODI data at BL and 2-years post op. Independent T-Tests assessed baseline radiographic differences in PT, PI-LL, and Schwab SVA modifier status between NF vs. F/SF patients. Utility data was calculated using the ODI converted to the SF-6D using published conversion methods. QALYs utilized a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs were calculated using the PearlDiver database. After accounting for complications, LOS, revisions, and death, cost per QALY at 2Y and life expectancy were calculated for NF, and F/SF patients. ICER was compared between non op and operative NF and F/SF patients at 2Y and life expectancy.
RESULT(S): Seventy-nine ASD patients met inclusion criteria. Descriptive statistics for the cohort were: age 51.0+/-6.8, 76% women, BMI 26.7+/-6.8, 54% osteotomy, 54% decompression, and 11.6+/-4.2 average levels fused. At BL, there were 48 NF, 26 F, and 4 SF pts. The average BL frailty for NF pts was 0.13+/-0.08, 0.39+/-0.06 for F, and 0.59+/-0.08 for SF pts. There were no differences in PT, PI-LL, or severe SVA Schwab modifier grades between NF or F/SF pts (all p>0.05). At 2-year follow up, there was no difference in the average cost of ASD surgery, $91,068.98 for NF patients and $90,888.53 for F/SF pts (p>0.05). The cost per QALY was higher for NF pts at 2 years vs F/SF pts ($464,239.62 vs. $321,107.89, p<0.05). If the utility gained was sustained to life expectancy, the cost per QALY was $70,796.43 for NF and $48,968.88 for F/SF (p<0.05). When compared to non op ASD pts, the ICER was $447,943.96 vs. $313,211.01 for NF and F/SF at 2 years, and $68,311.35 vs. $47,764.61 for NF and F/SF at life expectancy.
CONCLUSION(S): Frail and severely frail patients had lower cost per QALY compared to not frail patients at 3 years and life expectancy. In addition, when compared to a non operative cohort of ASD patients, frail and severely frail patients had lower ICER values. While these results support operative correction of frail and severely frail patients, it is important to note that these patients are often at worse baseline disability, which is closely related to frailty scores, and have more opportunity to improve postoperatively. In addition, there may be a threshold of frailty that is not operable due to the risk of severe complications that is not captured by this analysis. While future research should investigate economic outcomes at extended follow-up times, these findings support the cost effectiveness of ASD surgery at all frailty states. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: As the opioid crisis has gained national attention, there has been an increasing effort to decrease opioid usage. Simultaneously, patient satisfaction is a crucial metric in the American health care system, and has been closely linked to effective pain management in surgical patients. PURPOSE: Examine rates of pain medication prescription and concurrent patient satisfaction in spine surgery patients. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: A total of 1,729 patients undergoing any spine surgery. OUTCOME MEASURES: Rates of non-opioid pain medication prescriptions during hospitalization as part of a multimodal analgesia regimen, morphine milligram equivalents (MME) of opioids used during hospitalization, Press Ganey Satisfaction Survey data.
METHOD(S): Patients >=18yo undergoing spine surgery between 6/25/2017-6/30/2018 at a single institution by spine surgeons performing >=20 surgeries/quarter and who had medication data during hospitalization available included. Additional data collected included physician and procedure type. All data analyzed by quarter. Chi-squared test to compare percentages and ANOVA to compare means across quarters. Multivariate regression used to compare procedure-specific trends, controlling for age, revision and level of pain. Significance set at p<0.05.
RESULT(S): A total of 1,759 patients were included, 427 in Quarter 1 (Q1), 439 in Q2, 453 in Q3 and 440 in Q4. Mean total MME per patient hospitalization was 574.46, no significant difference between quarters (p=0.116). Mean MME/day per patient decreased between quarters (p=0.048), with highest mean 91.84 in Q2 and lowest 77.50 in Q4. From Q1 to Q4, three physicians had decreased mean MME/day (75.47->50.92, p=0.023; 115.70->46.05, p=0.013; 92.89->69.53, p=0.42, respectively) and two physicians had decreased total MME (815.88->243.15, p=0.004; 706.79->451.72, p=0.014, respectively). MME/day decreased (74.78->52.37, p=0.046) for discectomy cases. Controlling for age, revision and level of pain, total MME decreased for discectomies (p=0.006). Among all procedures, acetaminophen, NSAID and steroid prescription rates increased (9.13%->17.05%, p=0.001; 6.32%->9.77%, p=0.048; 9.13%->17.05%, p=0.001, respectively). This was also the case in fusion patients specifically (9.09%->17.99%, p=0.002; 2.77%->5.76%, p=0.024; 9.09%->17.99%, p=0.002, respectively). NSAID prescription in laminectomy patients also increased (3.23%->4.89%, p=0.041). Concurrently, benzodiazepine and GABA analog prescriptions decreased among all procedures (19.20%->10.68%, p<0.001; 9.84%->4.77%, p=0.025, respectively). Benzodiazepine prescriptions in fusion patients also decreased (24.51%->12.23%, p<0.001). No significant differences between quarters for mean pain ratings (p=0.521). Also no differences between quarters for responses to questions from Press Ganey Satisfaction Survey regarding how often staff talk about pain (p=0.164), whether staff talk about pain treatment (p=0.595) or recommending the hospital (p=0.096). This was also the case for top box ratings for the same questions (p=0.381, 0.837, 0.610, respectively). No significant differences between quarters for responses in all other patient satisfaction questions (range p=0.359-0.988) or their top box ratings (range p=0.359-0.988).
CONCLUSION(S): Over the studied time period, opioid use decreased and nonopioid prescriptions increased during hospitalization, while satisfaction scores remained unchanged. These findings indicate an increasing effort in reducing opioid use amongst providers, and suggest the ability to do so without impacting overall satisfaction rates. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Numerous advances have been made in the field of spine fusion, such as minimally invasive (MIS) or robotic assisted spine surgery. However, it is unknown how these advances have impacted the cost of care. PURPOSE: Compare the economic outcomes of lumbar spine fusion between open, MIS and robotic assisted surgery patients. STUDY DESIGN/SETTING: Retrospective review of a single center spine surgery database. PATIENT SAMPLE: A total of 360 propensity matched patients. OUTCOME MEASURES: Costs, EuroQol-5D (EQ5D), Cost per quality adjusted life years (QALY).
METHOD(S): Inclusion criteria: surgical patients >18 years undergoing lumbar fusion surgery. Patients were categorized into 3 groups based on procedure type: open, MIS or robotic. Open patients undergoing poster spinal fusion were considered as the control group. MIS patients included those undergoing transforaminal or lateral lumbar interbody fusion with percutaneous screws. Robotic patients were those undergoing robot assisted fusion. Propensity score matching was performed between all groups for the number of levels fused. Costs were calculated using the PearlDiver database, which reflects both private insurance and Medicare reimbursement claims for ICD-9 codes. For robot cases, costs were reflective of operational fees and initial purchase cost. Complications and comorbidities (CC) and major complications and comorbidities (MCC) were assessed according to CMS.gov manual definitions. QALYs and cost per QALY were calculated using a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs per QALY were calculated for both 1 year and life expectancy, assuming no loss of benefit.
RESULT(S): A total of 360 propensity matched patients (120 open, 120 MIS, 120 robot) met inclusion. Descriptive statistics for the cohort were: age 58.8+/-13.5, 50% women, BMI 29.4+/-6.3, op time 294.4+/-119.0, LOS 4.56+/-3.31 days, EBL 515.9+/-670.0 cc, and 2.3+/-2.2 average levels fused. Rates of postop complications were significantly higher in robotic cases versus open and MIS (43% vs. 21% and 22% for open and MIS, p<0.05). However, revision rates were comparable between all groups (3% open, 3% MIS, 5% robotic, p>0.05). After factoring in complications, revisions, and purchasing and operating fees, the costs of robotic cases was significantly higher than both open and MIS surgery ($60,047.01 vs. $42,538.98 open and $41,471.21 MIS). In a sub analysis of 42 patients with BL and 1Y EQ5D data, the cost per QALY at 1Y for open, MIS, and robot assisted cases was $296,624.48, $115,911.69, and $592,734.30. If utility gained was sustained to life expectancy, the cost per QALY was $14,905.75, $5,824.71, $29,785.64 for open, MIS, and robot assisted cases.
CONCLUSION(S): Numerous advances have been made in the field of spine surgery, however, there has been limited discussion of the effect these advances have on economic outcomes. When matched for levels fused, robot assisted surgery patients had significantly higher rates of complications and 30% higher costs of surgery compared to minimally invasive and open spine surgery patients. While 1 year economic outcomes weren't optimal for robotic surgery cases, the projected costs per quality adjusted life years at life expectancy were well below established acceptable thresholds. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Prior literature in patients with adult spine deformity has found that poor mental health at baseline is associated with worse postoperative outcomes. PURPOSE: The purpose of this study is to demonstrate that adolescent idiopathic scoliosis (AIS) patients with poor mental health at baseline can experience significant improvements with surgery. We hypothesize that in AIS, low SRS-22r mental health scores are largely due to the presence of deformity. The purpose of this study is determine if the correction of the deformity would potentially improve mental health scores. STUDY DESIGN/SETTING: Retrospective review of prospective AIS registry. PATIENT SAMPLE: Adolescents with idiopathic scoliosis. OUTCOME MEASURES: Mental health scores and percent of patients reaching minimum clinically important difference (MCID) at 2 years postoperative.
METHOD(S): A total of 1,532 (1,261 girls, 271 boys) with available baseline and 2-years follow-up SRS-22r scores were included. Patients with baseline mental health domain scores who were 1 standard deviation below the mean (< 3.3) were classified as "low mental health" score (LMH) group, and patients who were 1 standard deviation above the mean (> 4.7) were classified as "high mental health" score (HMH) group. The remaining patients were classified as "intermediate mental health" score (IMH). A minimal clinically important difference (MCID) of 0.6 was used for SRS-22r for analysis RESULTS: There were 247 patients in the LMH group, 1,015 in the MMH group, and 270 in the HMH group. Compared to baseline, all 3 groups demonstrated significant improvements in the overall SRS-22r scores at the 2-year follow-up: 0.8 +/-0.5 in the LMH group, 0.5 +/-0.4 in the IMH group, and 0.29 +/-0.35 in the HMH group (P<0.001 each). Further, at the 2-year follow-up, 72% of patients in the LMH group, 40% of patients in the IMH group, and 17% of patients in the HMH group reached MCID for SRS-22r. At the 2-year follow-up, there was no significant difference in the final SRS-22r score of the 3 groups.
CONCLUSION(S): In distinction from adult deformity patients, in the AIS population, alterations in normal body image may results in low mental health at baseline. These patients can experience significant benefit with surgery, and majority of these patients achieve MCID for the SRS-22r at the 2-year follow-up. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: The Miller et al adult spinal deformity frailty index (ASD-FI) correlates with increased complication risk after surgery; however, its development was not rooted in clinical outcomes, and the 40 factors needed for its calculation limit the index's utility in a clinical setting. PURPOSE: Develop a simplified, weighted frailty index for ASD patients. STUDY DESIGN/SETTING: Retrospective review of prospective ASD database. PATIENT SAMPLE: A total of 50 ASD patients. OUTCOME MEASURES: Health-related quality of life questionnaires: Oswestry Disability Index (ODI), SRS-22r, pain catastrophizing scale, Numerif Rating Scale (NRS) for Leg Pain.
METHOD(S): ASD patients (scoliosis>=20degree, SVA>=5cm, PT>=25degree, or TK >=60degree) with baseline ASD-FI component factors. Component ASD-FI parameters contributing to overall ASD-FI score were assessed via Pearson correlation. Top significant, clinically relevant factors were regressed against ASD-FI score to generate the modified ASD-FI (mASD-FI). Factors comprising the mASD-FI were regressed against the incidence of medical complications; weights for mASD-FI factors were calculated from these regression coefficients via the beta/Sullivan method. Total mASD-FI score was calculated by summing weights of expressed parameters, resulting in a score ranging from 0 to 21. Linear regression correlated ASD-FI and mASD-FI scores, and previously published ASD-FI cutoffs were used to generate corresponding mASD-FI frailty cutoffs: not frail (NF,<7), frail (7-12), severely frail (SF,>12). Analysis of variance assessed the relationship between increasing frailty category and validated baseline measures of patient pain and disability.
RESULT(S): Included: 50 ASD patients (52+/-20yrs, 78% female). All the following preoperative factors correlated with ASD-FI score (all p<0.039), and combined, accounted for 85.0% (p<0.001) of the variation in ASD-FI score: BMI <18.5 kg/m2 or >30 kg/m2 (weight: 5), depression (weight: 5), difficulty climbing stairs (3), presence of >3 medical comorbidities (2), leg weakness (2), difficulty getting dressed (1), bladder incontinence (1), and patient-reported deterioration in health within the past year (1). These factors were used to calculate the overall population's mean mASD-FI score: 5.7+/-5.2. Combined, these factors comprising the mASD-FI showed a trend of predicting the incidence of medical complications (Nagelkerke R2=0.558, Cox & Snell R2=0.399, p=0.065). Overall patient breakdown by mASD-FI frailty category: NF (70%), frail (12%), SF (18%). Increasing frailty category was associated with significant impairments in validated measures of disability, including ODI score (NF: 23.4, frail: 45.0, SF: 49.3, p<0.001), SRS-22r score (NF: 3.5, frail: 2.6, SF: 2.4, p=0.001), pain catastrophizing scale score (NF: 41.9, frail: 32.4, SF: 27.6, p<0.001), and NRS Leg Pain (NF: 2.3, frail: 7.2, SF: 5.6, p=0.001).
CONCLUSION(S): This study modifies an existing ASD frailty index and proposes a weighted, shorter mASD-FI. The mASD-FI relies less on patient-reported variables, and weights component factors by their contribution to adverse outcomes. As increasing mASD-FI score is associated with inferior clinical measures of pain and disability, the mASD-FI may serve as a valuable tool for preoperative risk assessment. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright