Faculty Bibliography

Background/UNASSIGNED:Outpatient anterior cervical discectomy and fusion (ACDF) is performed frequently, with studies demonstrating similar complication and readmission rates compared to traditional admission. Advantages include cost effectiveness, as well as lower risk of nosocomial infections and medical errors, which lead to quicker recovery and higher patient satisfaction. Protocols are needed to ensure that outpatient ACDF occurs safely. The objective of this study was to develop and implement a protocol with patient selection and discharge criteria for patients undergoing same-day discharge (SDD) ACDF and assess readmission rates. Methods/UNASSIGNED:A retrospective chart review was performed to identify patients undergoing 1 or 2 level primary ACDF between March 2016 and March 2017 who were eligible for SDD according to the institutional protocol (Figure 1, Table 2). Patients with identical surgery and discharge dates were grouped as SDD, and admitted patients were grouped as same-day admission (SDA). Using our electronic health record's analytics, readmissions in the 90-day postoperative period were identified. Results/UNASSIGNED:= .86). Conclusions/UNASSIGNED:The results of this study support the feasibility of outpatient ACDF and add a patient selection and discharge criteria to the literature. Proper identification of suitable patients using our protocol results in a noninferior readmission rate, allowing surgeons to continue to safely perform these surgeries with a low readmission rate. Level of Evidence/UNASSIGNED:3. Clinical Relevance/UNASSIGNED:SDD is safe in the appropriate patient population.

Background/UNASSIGNED:Robotic-guided navigation systems for pedicle screw placement has gained recent interest to ensure accuracy and safety and diminish radiation exposure. There have been no published studies using a new combined robotics and navigation system (Globus ExcelsiusGPS system). The purpose of this study was to demonstrate safety with this system. Methods/UNASSIGNED:This is a case series of consecutive patients at a single institution from February 1, 2018, to August 31, 2018. All patients who had planned placement of thoracic and lumbar pedicle screws using the combined robotics-navigation system were included. Chart review was performed for operative details. A subgroup analysis was performed on patients with postoperative computed tomography (CT) scans to assess screw placement accuracy using the Gertzbein and Robbins system. Acceptable pedicle screw position was defined as grade A or B. Results/UNASSIGNED:One hundred six patients were included, with 636 pedicle screws, 6 iliac screws, and 1 S2AI screw. Five cases were aborted for technical issues. In the remaining 101 patients, 88 patients had screws placed using preoperative CT planning and 13 patients using intraoperative fluoroscopy planning. All screws except for 5 pedicle screws in 2 patients were placed successfully using the robot (99%). These 5 pedicle screws were placed by converting to a fluoro-guided technique without robotic assistance. Eighty-six patients had screws placed using a percutaneous technique, and 15 patients had screws placed using an open technique. Ninety-eight patients underwent interbody placement: 28 anterior lumbar interbody fusions (ALIFs), 12 lateral lumbar interbody fusions (LLIFs), and 58 transforaminal lumbar interbody fusions (TLIFs). All ALIFs and LLIFs were performed prior to placement of the screws. Four LIF patients had screws placed in the lateral position. No patients had screw-related complications intraoperatively or postoperatively, and no patients returned to the operating room for screw revision. Thirteen patients underwent postoperative CT for various reasons. Of the 66 pedicle screws that were examined with postoperative CT, all screws (100%) had acceptable position. Conclusion/UNASSIGNED:This study demonstrates that the combined robotics and navigation system is a novel technology that can be utilized to place pedicle screws and pelvic screws safely and has the potential to reduce screw-related complications. Level of Evidence/UNASSIGNED:4 (case series).

BACKGROUND CONTEXT: Antifibrinolytic agents are used during ASD surgery to minimize blood loss and transfusion requirements. Tranexamic acid (TXA) reduces the risk of blood loss and transfusion after ASD surgery, but there persists concern for prothrombotic effects, myocardial infarction, stroke, and postoperative neurologic events including seizures. PURPOSE: To investigate perioperative blood loss and transfusion after TXA for ASD surgery. STUDY DESIGN/SETTING: Retrospective review of prospectively collected single center database. PATIENT SAMPLE: 469 patients who received TXA, and 354 patients who did not receive TXA. OUTCOME MEASURES: Perioperative blood loss and blood product transfusion rate, and complications.
METHOD(S): Using a single-institution multi-surgeon database, we performed a retrospective review of patients undergoing ASD surgery from 2011-2018. We identified 469 patients who received TXA, and 354 patients who did not receive TXA. We investigated perioperative blood loss and blood product transfusion rate, and complications occurring after surgery.
RESULT(S): There was no significant difference in age, BMI, or frailty between the TXA (age: 45 +/- 23, BMI: 25 +/- 6) and non-TXA group (age: 47 +/- 24, BMI: 26 +/- 7). The prevalence of coronary artery disease, chronic kidney disease, and history of pulmonary embolism was higher in the non-TXA group, presumably due to surgeon preoperative screening, with no difference in other medical comorbidities. There were more revision surgeries and pelvic fixation procedures in the TXA group, with no other differences in surgical complexity. The group that received TXA had significantly lower EBL (1693 +/- 1343 mL vs 2009 +/- 1892 mL, p=0.019), and were transfused less platelets intraoperatively (.07 +/-.3 U vs 0.25 +/- 0.86 U, p=0.012). There was no difference in rates of perioperative pRBC transfusion between the groups. The most common complications in both groups were ileus and urinary retention. There was no difference in rate of thrombotic, cardiac, or renal complications, or seizures between the two groups. There was no significant difference in 90-day complication, readmission, or revision rates.
CONCLUSION(S): Among patients undergoing ASD surgery, TXA was associated with a lower estimated blood loss, without a higher risk for any morbid event. To our knowledge, this is the largest study to date to evaluate the safety of TXA for ASD surgery. FDA DEVICE/DRUG STATUS: Unavailable from authors at time of publication.
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BACKGROUND CONTEXT: Lateral interbody fusion (LLIF) is often performed with biologic adjuvants to promote fusion. Commercially available bone allograft containing allogeneic stem cells (ASC) and bone morphogenetic protein-2 (BMP) are designed to promote fusion while avoiding the morbidity of iliac crest autograft; however, no study to date has directly compared the two in LLIF. The ASC studied is Osteocel Pro (NuVasive, Inc). PURPOSE: This non-industry funded study compares fusion rate, complications, and costs between LLIF with BMP and ASC. STUDY DESIGN/SETTING: Single center retrospective comparative study. PATIENT SAMPLE: Patients with 1-3 lumbar levels treated with LLIF. OUTCOME MEASURES: Outcomes measures are fusion at 1 year postoperative, complication rates, length of stay, and costs.
METHOD(S): A retrospective chart review was conducted to identify patients treated with LLIF and ASC or BMP from February 2012 through September 2017. Patients were included who had from 1-3 lumbar levels treated with LLIF and at least 1 year of radiographic follow up. Interbody fusion was assessed on lumbar X-ray images using a validated scale.
RESULT(S): A total of 94 patients were included representing 162 levels fused. Of these, 74 patients and 133 levels were treated with BMP; 20 patients and 29 levels were treated with ASC. Comparing patients treated with BMP or ASC, there were no differences in age [61.6 vs 60.4, p=0.7], BMI [29.8 vs 28.3, p=0.3], gender [60.8% vs 55.0% female], smoking status [12.2% vs 10.0%, p=1], diabetes [28.4% vs 15.0%, p=0.2], Charleston Comorbidity Index [4.3 vs 3.5, p=0.2], revision status [47.3% vs 45.0%, p=0.9], intraoperative complications [4.1% vs 5.0%, p=1], postoperative complications [37.8% vs 30.0%, p=0.5], or blood loss [881 vs 528ml, p=0.2]. More levels were fused in the BMP group (1.8 vs 1.45, p=0.04) and the BMP group tended toward a longer length of stay [4.8 vs 3.8 days, p=0.06]. There was a nonsignificant trend toward a higher fusion rate with BMP vs ASC[98.5% vs 93.1%, p=0.1]. The average amount of rhBMP used per level was 2.0 cc compared to 5.9 cc of ASC. There was no difference in the cost of the BMP per level compared with ASC [4.45% vs 4.80%, p=0.33], but the BMP group tended toward a higher cost of total care [103.5% vs 87.6%, p=0.1].
CONCLUSION(S): ASC and BMP are both acceptable adjuvants in LLIF that demonstrate comparable fusion rates at 1 year with comparable cost in the setting of similar groups of patients. The radiographic fusion rate seen in our study compares to previous reports in the literature using ASC. Cost considerations are becoming ever more cogent in spine surgery; the results of this study can inform decision making regarding which biologic adjuvant to use in lumbar interbody fusion. FDA DEVICE/DRUG STATUS: Osteocel (Approved for this indication), rhBMP (Infuse) (Not approved for this indication)
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BACKGROUND CONTEXT: Lumbar herniated nucleus pulposus (HNP) is a common spinal pathology often treated by microscopic lumbar discectomy (MLD), though prior reports have not demonstrated which preoperative MRI factors may contribute to significant clinical improvement after MLD. PURPOSE: To analyze the MRI characteristics in patients with HNP that predict meaningful clinical improvement in Health Related Quality of Life scores (HRQL) after MLD. STUDY DESIGN/SETTING: Retrospective clinical and radiological study of patients undergoing MLD for HNP at a single institution over a two year period of time. PATIENT SAMPLE: Eighty-eight patients receiving MLD treatment for HNP. OUTCOME MEASURES: Cephalocaudal canal migration; canal & HNP anterior-posterior (AP) lengths and ratio; canal & HNP axial areas and ratio; hemi-canal & hemi-HNP axial areas and ratio; disc appearance (black, grey or mixed), baseline (BL) and 3-month (3M) postoperative HRQL scores.
METHOD(S): Patients >18 years old who received MLD for HNP with BL and 3M HRQL scores of PROMIS (Physical Function, Pain Interference, and Pain Intensity), ODI, VAS Back, and VAS Leg scores were included. HNP and spinal canal measurements of cephalocaudal migration, AP length, area, hemi-area, and disc appearance were performed using T2 axial and sagittal MRI. HNP measurements were divided by corresponding canal measurements to calculate AP, Area, and Hemi-Area ratios. Using known minimal clinically importance differences (MCID) for each DELTAHRQoL score, patients were separated into two groups based on whether they reached MCID (+) or did not reach MCID (-). The MCID for Pain Intensity was calculated using a decision tree. A linear regression illustrated correlations between PROMIS vs ODI and VAS Back/Leg scores. Independent t-tests and chi-square tests were utilized to investigate significant differences in HNP measurements between the (+) and (-) MCID groups.
RESULT(S): Eighty-eight MLD patients were included (age=44.6+/-14.9, 38.6% female). Pain Interference and pain intensity were strongly correlated with ODI and VAS Back/Leg (R>=.505), and physical function was significantly correlated with ODI and VAS Back/Leg (R=-.349) (all p<.01). The strongest MRI predictors of meeting HRQL MCID were grey disc appearance, HNP area (>116.6 mm²), hemi-HNP Area (>84.6 mm²), and Hemi-Area Ratio (>51.8%); (+) patients were 2.7 times more likely to have a grey HNP than (-) patients in 5 out of 6 HRQL score comparisons (p<.025). Also, (+) patients had larger HNP areas than (-) patients had in 5 out of 6 HRQoL score comparisons (116.6 mm² +/- 46.4 vs 90.0 mm² +/- 43.2, p<.04), and had larger hemi-HNP areas than (-) patients had in 4 out of 6 HRQL score comparisons (84.6 mm² +/- 38.8 vs 66.3 mm² +/- 29.7, p<.04). (+) patients had a greater hemi-area ratio than (-) patients had in 4 out of 6 HRQL score comparisons (51.8% +/- 14.7 vs 43.9% +/- 14.9, p<.05).
CONCLUSION(S): Patients who met MCID after MLD had larger HNP areas by 26.6 mm² and larger hemi-HNP areas by 18.3 mm² than those who did not meet MCID. These patients were also 2.7x more likely to have a grey HNP compared to patients who did not meet MCID. When accounting for HNP area relative to canal area, patients who met MCID had a 7.9% greater Hemi-HNP canal occupation than patients who did not meet MCID. The results of this study suggest that preoperative MRI parameters can be useful in predicting patient reported improvement after MLD. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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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.
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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.
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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.
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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.
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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.
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