Faculty Bibliography

BACKGROUND CONTEXT: As adult spinal deformity (ASD) prevalence increases in our ever-aging population there is a concomitant increase in poor bone quality. ASD surgery is expensive and carries a high complication profile. It is important to optimize modifiable preoperative risk factors, such as osteopenia or osteoporosis. Additional diagnostic modalities such as a DEXA can add cost, delay diagnosis, and can be an additional insurance hurdle. Some studies suggest HU's can be utilized as a proxy for frailty, but it is unclear if this is useful in risk stratification. PURPOSE: Our goal was to evaluate the relationship between bone health as measured by HU's and PJK and identify a HU threshold in which PJK risk is increased. We hypothesize that HU will correlate with occurrence of PJK after ASD surgery. STUDY DESIGN/SETTING: Retrospective review of a prospective, multicenter ASD database. PATIENT SAMPLE: Of 1,330 pts eligible, 997 (74.9%) had complete 2Y follow-up. Of these, 605 meet inclusion criteria with 110 (18.18%) patients having a PJK. OUTCOME MEASURES: Development of PJK within 2 years of surgery.
METHOD(S): Operative ASD patients (scoliosis >20, SVA>5cm, PT>25, or TK>60) with available baseline (BL) and 2-year (2Y) radiographic and HRQL data were included if they had a preop CT. HU were measured from axial views within the cancellous body (x3) at both L1 and UIV with the mean value calculated for each. Threshold linear regression with Bayesian information criteria was utilized to identify optimal cut-offs of risk factors for PJK. Multivariable analysis (MVA) controlled for PJK prophylaxis and surgeon. Additionally, risk factors identified were controlled against each other.
RESULT(S): Threshold regression identified that cut-offs of <125 HU for UIV, >63 years for age, >0.31 for ASD-FI, and >47degree for preoperative T4-12 thoracic kyphosis, and <10 levels fused were predictive of PJK on bivariate analysis (P<0.05 for all). On MVA, age > 63 years old (OR 4.7; P = 0.003), female gender (OR 3.33; P=0.035), HU at UIV vertebrae <125 (2.83; P=0.008), ASD-FI >0.31 (OR 4.02; P=0.011), TK > 46degree (OR 3.75; P=0.003), and < 10 levels fused (OR 3.31; P=0.0310) were associated with increased odds of PJK.
CONCLUSION(S): Bone health as measured by HU appears to be an independent predictor of PJK after ASD surgery, specifically values <125 at the UIV. It also parallels frailty in prediction of PJK and can potentially be used as a proxy for frailty assessment. This can be easily measured and could help with risk stratification in the future. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adult spinal deformity (ASD) and cervical deformity (CD) surgery has seen great improvements in increasing perioperative patient safety and decreasing patient mortality. Previous studies have also demonstrated relatively higher risk of death in cervical deformity surgeries, yet there remains a paucity of literature comparing and contrasting the comorbidities and predictive factors associated with death in ASD versus CD surgery. PURPOSE: To assess morbidity and mortality rates and potential correlations with frailty in ASD vs CD patients. STUDY DESIGN/SETTING: Retrospective review of prospective cervical deformity (CD) and adult spinal deformity (ASD) databases. PATIENT SAMPLE: There were 689 ASD patients, 290 CD patients: 979 total. OUTCOME MEASURES: Demographic factors; baseline comorbidities; intra/postoperative complications; mortality.
METHOD(S): Operative CD patients 18yrs with pre-(BL) and up to 5-year (5Y) postoperative radiographic/HRQL data were assessed. Differences in demographics, radiographic alignment, and complication rates were assessed via means comparison analyses. Conditional backstep binary logistic regression analysis identified predictive factors for mortality. Kaplan-Meier curves assessed survivorship of expired patients. Cox regression assessed survivability adjusting for BL frailty status. Logrank analysis determined differences in the survival distribution between ASD and CD patients.
RESULT(S): A total of 625 patients met inclusion criteria (417 ASD, 208 CD). Within 5Y, 12 ASD patients (2.88% of ASD cohort) and 16 CD patients (7.69% of CD cohort) expired (p=.004). At baseline, ASD and CD patients differed significantly in BL Frailty score (0.29 vs 0.41, p.05). No significant differences were noted in BL disability per EQ5D-VAS (p>.05). In terms of baseline self-reported comorbidities in expired patients, the three most common for ASD patients were: arthritis (46%), hypertension (31%) and anemia (23%). In CD patients, the three most common comorbid conditions were: osteoporosis (50%), previous myocardial infarction (17%) and any cancer (17%). Complications analysis revealed no significant differences in major, minor or intraoperative complications between ASD or CD patients, nor between expired vs living patients (all p>.05). Similarly, there were no significant differences in mortality overall within 30 days, between 30 and 90 days, nor >90 days after surgery between ASD or CD patient cohorts (all p>.05). Regression analysis revealed that when accounting for age, BMI and gender, only frailty status remained a significant predictor of death overall (p=.047). Mean survival time for ASD was 84.11 weeks versus 65.17 in CD patients(chi2(1)=.748, p=.387).
CONCLUSION(S): Total 5-year all-cause mortality in adult spinal deformity and cervical deformity patients remains below 3% despite high rates of comorbidities, suggesting rigorous patient selection criteria plays an important role in maintaining the safety of such surgeries. This study demonstrates that while cervical deformity patients demonstrate greater incidence of death postoperatively, significantly increased baseline frailty status may be the principle cause of such results and should be considered when assessing surgical risks versus benefits. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Identifying the components needed for an optimal adult spinal deformity (ASD) surgical outcome could help inform surgeons and improve ASD treatment. However, defining the components that create an optimal outcome for ASD surgery is challenging because outcome metrics depend on multiple perspectives. A patient may receive a technically successful complication-free surgery but may report dissatisfaction with the treatment outcome. Conversely, a patient may incur multiple postoperative complications with high societal cost but report satisfaction with the surgical outcome. PURPOSE: (1) Define an "optimal" ASD surgical outcome by integrating outcome metrics from multiple perspectives, and (2) identify the patient-specific and surgical components of ASD treatment that surgeons can employ to improve ASD surgery by creating a model that predicts a multi-perspective "optimal" surgical outcome. STUDY DESIGN/SETTING: Prospective, multicenter analysis. PATIENT SAMPLE: ASD patients enrolled into a prospective multicenter study. OUTCOME MEASURES: Scoliosis Research Society-22r questionnaire (SRS-22r), Oswestry Disability Index (ODI), postoperative complications.
METHOD(S): Surgically treated ASD patients prospectively enrolled into a multicenter study from 2009-2018 were assessed at minimum 2-year follow-up for optimal outcome defined as (1) no major postoperative complication or complication requiring surgery, (2) patient reached MCID for ODI and SRS-22r subscore, and (3) patient satisfied and indicates would have the surgery again. Demographic, radiographic, PROM and surgical variables were assessed for associations with optimal outcome. Multivariate regression models were built based on level of upper instrumented vertebra (UIV) to identify variables that created a best fit predictive model for optimal outcome by R2 maximization and AIC/BIC minimization.
RESULT(S): Of 1291 patients, 788 (mean 3.5 years follow-up), were eligible for study and evaluated. Optimal outcome patients (OP; n=196) had less preoperative opioid use (47.5% vs 56.8%) and fewer histories of prior spine surgery (65.4% vs 77.3%) than nonoptimal outcome (NO; n=592), respectively (p 0.05). Creation of the best fit predictive model for optimal outcome demonstrated synergy between several modifiable variables including preoperative BMI and opioid and tobacco use, final SVA and scoliosis, and use of supplemental rods and PJF prophylaxis. Refining the model for specific surgeries based upon UIV demonstrated increased synergistic impact of the modifiable variables and predictive accuracy (thoracolumbar UIV R2 =0.41; upper thoracic UIV R2 =0.77).
CONCLUSION(S): No single surgical or radiographic variable is independently predictive of an a priori defined multiperspective optimal outcome following ASD surgery. However, predictive modeling identified preoperative BMI, opioid and tobacco use, final SVA and scoliosis, and use of supplemental rods and PJF prophylaxis as variables surgeons can optimize and/or employ that act synergistically to predict an optimal ASD surgical outcome. Future research will focus on development of predictive models that highlight the synergistic effects of patient specific and interventional variables to improve surgical outcomes. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Recent literature has pointed to the rising use of prone lateral versus lateral decubitus positioning in minimally invasive spine surgery (MISS) as a method to reduce operative time, increase patient safety, and aid in surgical accessibility. However, there is a paucity of literature as to how prone lateral and lateral decubitus positioning compares in terms of reaching optimal postoperative outcomes and reducing complication rates. PURPOSE: To assess differences between prone lateral and single-position lateral decubitus positioning compares in terms of reaching optimal postoperative outcomes and reducing complication rates. STUDY DESIGN/SETTING: Retrospective review of prospective MIS database. PATIENT SAMPLE: A total of 524 MIS patients. OUTCOME MEASURES: HRQLs; complications; surgical factors.
METHOD(S): MISS patients with BL) and 2-year(2Y) postop radiographic/HRQL data were included. Patients positioned in the prone latera (PL) or single-position lateral decubitus (LD) position were isolated. At 2Y, an optimal outcome score was calculated using 4 equally weighted criteria: 1) achieving ideal PT per SRS-Schwab at 2Y, 2) Achieving ideal PI-LL per SRS-Schwab at 2Y, 3) No complication requiring reoperation, 4) Achieving NRS MCID by Salaffi et al. criteria; optimal score threshold was set at meeting 2 of 4 criteria. Means comparison analysis assessed differences in radiographic and clinical outcomes at BL and 1Y postoperatively. ANCOVA assessed estimated marginal means adjusting for BL age and revision status.
RESULT(S): Thirty-four PL and 36 LD patients were included (54.40+/-12.49 years, 40% female, 30.93+/-6.52 kg/m2, mean CCI: 2.23+/-1.55) were included. At baseline, patients were comparable in age, gender, BMI and CCI (all p>.05). Perioperatively, PL patients demonstrated significantly lower operative time (200.09 vs 284.54 min, p=.007) and EBL (332.35 vs 192.05 mL, p=.027). Though optimization scores were equivalent between groups (p=.160), PL patients demonstrated significantly lower perioperative complication rates (p=.012), neurological complication rates (p=.006), and had a fewer number of total complications by 2Y (p=.014). When controlling for BL age and revision status, the PL patients demonstrated consistently fewer intra- and perioperative complications as well (both p<.015). In terms of patient-reported outcomes, PL patients also demonstrated significantly improved NRS-Leg scores compared to LD patients by 1Y (p=.038).
CONCLUSION(S): Patients placed in the PL position during minimally-invasive adult spinal deformity surgery demonstrate decreased mean operative times and decreased intraoperative invasiveness and blood loss versus patients operated on via single-position LD positioning. Though overall rates of achieving optimal outcome remain comparable, PL approach should be considered as there may be significant additional benefit in reducing peri- and postoperative complications by 2Y. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adaptation of age-adjusted alignment has gained popularity for its correlation with clinical improvement and lowering rates of proximal junctional kyphosis. Age-adjusted parameters correlate with outcomes. However, frailty may be a better predictor of each following ASD surgery. PURPOSE: To adjust the Sagittal Age-Adjusted Score (SAAS) to accommodate frailty in alignment considerations will increase the predictability of clinical outcomes and junctional failure. STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 689 ASD Patients. OUTCOME MEASURES: Mechanical complications, PJF, PJK and ODI.
METHOD(S): Included: surgical ASD pts with 2Y data. Frailty assessed by ASD modified Frailty Index (ASD-mFI).
Outcome(s): proximal junctional kyphosis (PJK) and failure (PJF), major mechanical complications, and Smith et al Best Clinical Outcome (BCO), defined as ODI 4.5. Linear regression analysis established a 6W score based on SAAS component scores, frailty and ODI US norms per published by Lafage et al. Logistic regression followed by conditional inference tree (CIT) analysis generated categorical thresholds. Logistic regression analysis controlling for age, baseline deformity and revision status generated odds ratios for the continuous score. Thirty percent of the cohort was used as a random sample for internal validation.
RESULT(S): There were 412 pts included. BL frailty categories: 57% not frail, 30% frail and 14% severely frail. Overall, by 2Y, 39% of patients developed PJK, 8% PJF, 21% mechanical complications, 22% underwent reoperation and 15% met BCO. SAAS only correlated with development of PJF. The ASD-mFI demonstrated correlation with all outcomes except PJK (all p1.4, offset: 0.75-1.4, sseverely offset:.05). Internal validation saw these outcomes maintain significance between categories, with significant adjusted correlation to meeting BCO (OR: 3.8, 1.1-13.5; p=.037).
CONCLUSION(S): Consideration of physiologic age, in addition to chronological age, may be beneficial in management of operative goals to maximize clinical outcomes while minimizing junctional failure. This combination enables the spine surgeon to fortify a surgical plan for even the most challenging patients undergoing adult spinal deformity surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adult spinal deformity (ASD) refers to multiple types of spinal deformity. This study used a prospective multicenter database of patients with "complex" surgical ASD to derive a data-driven classification of different deformity patterns, and assessed if such patterns have distinct clinical outcomes. PURPOSE: Use an AI-based unsupervised approach to identify patterns of ASD. STUDY DESIGN/SETTING: Retrospective analysis of a multi-center prospective database. PATIENT SAMPLE: A total of 286 patients with complex ASD who underwent surgical correction. OUTCOME MEASURES: Operative decision-making and 30-day adverse events.
METHOD(S): Complex surgical ASD included severe deformity, surgical complexity or advanced age with a multilevel fusion. An unsupervised cluster analysis that allowed for 10% outliers was used to identify different patterns of deformity. Perioperative outcomes of these clusters were then compared using ANOVA, Kustal-Wallis, and Chi-Squared analyses as indicated, with p-value < 0.05 considered significant.
RESULT(S): The Hyper-Kyphosis (Hyper TK, n = 31) group had a mean thoracic kyphosis of 82.6+/-17.6degree, lumbar hyperextension (PI-LL: -20.4+/-14.7degree) and relatively straight coronal curvatures. Hyper-Kyphosis patients were the youngest (mean age 48+/-20 years) and had the lowest disability (mean ODI 32.9+/-17.1) and pain scores (median NRS back 6 IQR 3 to 8, median NRS leg 1 IQR 0 to 4). The Severe Coronal (Coronal, n = 91) group had a mean thoracic Cobb of 44.7+/-17.8degree and a mean thoraco-lumbar Cobb of 57.9+/-16.5degree with preserved global sagittal alignment. Coronal patients had moderate disability (mean ODI 33.5+/-18.8), functional impairment (PCD: 34.4+/-12.3) and pain scores (median NRS back 7 IQR 5 to 8, median NRS leg 4 IQR 0 to 7). The Severe Sagittal (Sev. Sag. n=79) group had a severe spino-pelvic mismatch (42.9+/-12.9degree) and global sagittal deformity (24.3+/-7.9degree). Sev Sag had higher BMIs (28.9+/-5.9), high levels of disability (mean ODI 49.3+/-15.6) and low appearance scores (2.3+/-0.7). Finally, the Moderate Sagittal (Mod. Sag. n=85) group had moderate deformities without distinctive radiographic characteristics, a mean age of 68.8+/-7.8degree, the highest PROMIS pain interference sub-scores (65.2+/-5.8), high levels of disability (mean ODI 47.6+/-15.3) and back pain (NRS back 7 IQR 6 to 9), and poor overall quality of life (mean SRS total 2.8+/-0.6). Thirty-day adverse events were equivalent. Hyper TK and Coronal patients had the longest constructs, but fusion to the pelvis was most common in Mod Sag (89.4%) and Sev Sag (97.5%) deformities. Coronal patients had more osteotomies per case (median 11 IQR 6.5 to 14), longer OR times, and more 30-day implant-related complications (5.5%). Sev Sag and Hyper TK patients were more likely to require a 3-column osteotomy (43% and 32.3%, respectively). Sev Sag deformities were more likely to require interbody implants (29.1%) and operative wound debridement (7.6%). Hyper TK patients had shorter hospital stays.
CONCLUSION(S): AI methodologies identified 4 distinct patient clusters within a large population of surgically treated ASD patients. Each ASD cluster presented with 1) a unique spinal deformity pattern, 2) reported distinct pathognomonic health deficits, 3) received consistent surgical treatment across 11 centers, and 4) had characteristic perioperative complications and hospital stays. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Despite studies reporting the efficacy of BMP to promote surgical spinal fusion, hospital systems and third-party payors continue to deny use of BMP, claiming high cost and lack of long term follow up. PURPOSE: Perform a propensity score matched analysis of complications and cost-effectiveness for surgically treated adult spinal deformity (ASD) patients receiving BMP vs no BMP. STUDY DESIGN/SETTING: Prospective, multicenter, propensity score matched analysis. PATIENT SAMPLE: ASD patients enrolled into a prospective 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), cost of care, cost/QALY, postoperative complications.
METHOD(S): Surgically treated ASD patients prospectively enrolled into a multicenter study from 2009-2018 were assessed for receiving BMP or NOBMP (iliac crest bone graft and allograft only) at the time of surgery. BMP and NOBMP cohorts were propensity score matched (PSM) for age, BMI, frailty, total levels fused, fusion to the pelvis, osteotomies, interbody fusion and supplemental rod use. Postoperative alignment, complications, rod fractures, patient-reported outcomes (PROMs), cost of care (based on DRG reimbursements adjusted to 2021 US dollars), were evaluated at minimum 3-year follow-up, and cost/QALY calculated at 1-,2-, and minimum 3-year follow-up.
RESULT(S): Of 888 patients, 483 (mean 4.2 years follow-up, range 2.9 to 8.8) were evaluated. Mean BMP dosage was 27.6 mg total (range 1 to 200), 2.2 mg/level posterior (range 0 to 25) and 1.7 mg/level interbody (range 0 to 18). BMP (n=407) had similar demographics, osteotomies, total and interbody levels fused, preop PROMs, follow-up duration, and pre- and postoperative spinal alignment as NOBMP (n=76; p>0.05). BMP had fewer implant failures (0.17/patient vs 0.33/patient; p 0.05). At last follow-up, BMP had better SF-36 social function (46.7 vs 43.9) and SF-36 mental component scores (51.5. vs 47.8) than NOBMP (p <0.05, respectively). BMP had lower mean total cost of care/patient ($78,679.61 vs $103,388.78) and lower cost/QALY ($22,455.48 vs $32,947.68) at last follow-up vs NOBMP, respectively (p < 0.05). Revision surgery rates were similar for BMP vs NOBMP (0.32 vs 0.42/patient, p=0.11); however, costs of revision surgery were less for BMP ($11,114.33) vs NOBMP ($22,912.53, p <0.05).
CONCLUSION(S): Propensity score matched analysis demonstrated BMP use in ASD surgery at mean 4-year follow-up was associated with decreased implant fracture rates, lower treatment costs and better cost/QALY than NOBMP. Hospital systems, administrators and third-party payors should consider that the initial cost of BMP use at index surgery may be offset by decreased total cost of care and improve cost/QALY for ASD patients. FDA DEVICE/DRUG STATUS: Bone morphogenetic protein: Investigational.
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BACKGROUND CONTEXT: Distal junctional kyphosis (DJK) is one of the most common complications in adult cervical deformity (ACD) correction. The utility of radiographic alignment alone in predicting and minimizing DJK occurrence warrants further study. PURPOSE: To investigate the impact of postoperative radiographic alignment on development of DJK in ACD patients. STUDY DESIGN/SETTING: Retrospective cohort study of a multicenter prospective ACD database. PATIENT SAMPLE: A total of 450 ACD patients. OUTCOME MEASURES: DJK after cervical deformity surgery.
METHOD(S): ACD patients (18 yrs) with complete baseline (BL) and two-year (2Y) radiographic data were included. DJF was defined as DJK greater than 15 or DJK with reop. Multivariable logistic regression (MVA) identified 3-month predictors of DJK. Conditional inference tree (CIT) machine learning analysis determined threshold cutoffs. Radiographic predictors were combined in a model to determine predictive value using area under the curve (AUC) methodology. "Match" refers to ideal age-adjusted alignment.
RESULT(S): A total of 140 cervical deformity patients met inclusion criteria (61.3yrs, 67%F, BMI 29kg/m², CCI 0.96+/-1.3). Surgically, 51.3% had osteotomies, 47.1% had a posterior approach, 34.5% combined approach, 18.5% anterior approach, with an average 7.6+/- 3.8 levels fused and EBL of 824 mL. Overall, 33 patients (23.6%) developed DJK, and 11 patients (9%) developed DJF. MVA controlling for age, and baseline deformity, followed by CIT found 3M cSVA <3.7 cm (OR.2, 95% CI.06-.6), and TK T4-T12 <50 (OR.17, 95% CI.05-.5, both p <.05) were significant predictors of a lower likelihood of DJK. Receiver operator curve AUC using age, T1S match, TS-CL match, LL-TK match, cSVA <3.7 cm, and T4-T12 <50 predicted DJK with an AUC of.91 for DJK by 2 years, and.88 for DJF by 2 years.
CONCLUSION(S): These findings suggest postoperative radiographic alignment is strongly associated with distal junctional kyphosis. When utilizing age-adjusted realignment in addition to newly developed thresholds, a suggested postoperative cSVA target of 3.7 cm and thoracic kyphosis less than 50, it is possible to substantially reduce the occurrence of distal junctional kyphosis and distal junctional failure. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Loss of lumbar curvature is often expressed as an angular regional loss. Previous work comparing adult spinal deformity (ASD) lumbar alignment to their age-and-PI adjusted normative value demonstrated that, contrary to general belief, a large proportion of the curvature is lost proximally (L1-L4). This study is a follow-up looking not only at regional angles, but also at the spinal contour collectively. PURPOSE: Investigate the difference of lumbar shape between ASD and age-and-PI adjusted normative values. STUDY DESIGN/SETTING: Retrospective review of an ASD registry. PATIENT SAMPLE: A total of 119 asymptomatic volunteers and 362 ASD patients. OUTCOME MEASURES: Sagittal alignment of the lumbar and thoracolumbar spine measures using vertebra pelvic angle from L5 to T10.
METHOD(S): Before studying ASD patients, 119 asymptomatic volunteers with full-body, free-standing radiographs were used to identify age-and-PI models of each vertebra pelvic angle (VPA) from L5 to T10, a validated methodology characterizing the detailed shape of the spine. Our study cohort was a registry of surgical primary ASD patients without coronal malalignment (SRS-Schwab Type=N). The formulas developed in the asymptomatic population were applied to the ASD group to calculate an age-and-PI normative spine shape for each patient. Loss of lumbar lordosis was defined as the offset between age-and-PI normative value and pre-operative spino-pelvic alignment. Patients were stratified into four groups by the amount of lordosis lost, ranging from "no loss" to "30degree loss." Paired t-tests were performed to compare actual and normative VPA shapes within each group.
RESULT(S): Out of 1,495 patients enrolled in this registry, 453 were primary cases, and 653 were categorized as a Schwab type N, leading to a cohort of 362 patients (age=64.4+/-13, 57.1% F). Pre-operative alignment demonstrated a large variability with a mean PI-LL of 15degree+/-21, distal LL=31degree+/-15, and PI=55degree+/-13. Compared to their age-and-PI normative values, ASD patients demonstrated a significant lordosis loss of 17degree+/-19 with the following distribution: 14.1% no loss (mean: 0.1+/-2.3), 22.9% with 10degree loss (mean: 9.9+/-2.9), 22.1% with 20degree loss (mean: 20.0+/-2.8), and 29.3% with 30degree loss (mean:33.8+/-6.0). Comparison of the VPAs (and therefore the shape) between each LL group and the normative shape demonstrated that the "no loss" patients had a lumbar spine slightly anterior to the normative shape from L4 to T10 (VPA difference of 2degree). The shape of the "small deformity" group (10degree) superimposed on the normative one from L5 to L2 (VPA with p>0.1) and became anterior at the L1 level. As the lordosis loss increased, the offset between ASD and normative shapes began to propagate to the distal levels and became significant extending caudally to the L3 level for the "20degree loss" group and further down to L4 for the more severe group.
CONCLUSION(S): As the deformity progresses and the loss of lordosis increases, the difference between ASD shape and normative shape happens first proximally and then progresses incrementally caudally with increasing deformity. Understanding the spinal contour and the location of this loss, in addition to regional parameters, may be key to achieving a sustainable correction by identifying optimal and personalized post-operative shape. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adolescent idiopathic scoliosis (AIS) affects up to 4% of adolescents. As of yet, the characterization of traumatic injuries in AIS patients is unknown. PURPOSE: To compare the risk of varying fracture locations after blunt trauma between patients with and without AIS. STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: The Kid's Inpatient Database (KID) was queried from 2003 to 2009 to identify all patients aged 0-20 with AIS admitted for acute trauma. OUTCOME MEASURES: The rates of various spinal fracture patterns as well as risk factors for vertebral fracture.
METHOD(S): KID was queried for AIS patients aged 0-20 years, from 2003 through 2009. AIS patients admitted for acute trauma were isolated. Mechanisms of injury (MOI), fracture locations and surgical procedures were assessed. Trauma AIS patients were then propensity-score matched to a general (Gen) trauma population of 323,729 KID patients, using age, sex and MOI. Fracture types were compared utilizing Chi-square and t-tests. Logistic regression analysis predicted relative odds of fracture in AIS patients.
RESULT(S): Of 41,142 AIS cases identified, 442 patients suffered acute blunt trauma (2003: 112; 2006: 139; 2009: 186). Of those, the most prevalent MOIs were MVA (37.1%), pedestrian struck (PS) (22.9%), falls (18.3%) and assault (7.6%). Of the 442 acute blunt trauma patients, 99 (22.3%) sustained vertebral fracture. Of those, 25 patients had cervical fractures (MVA 66.52%, PS 24.14%, fall 6.9%), 23 thoracic (MVA 47.8%, PS 21.7%, fall 26.1%), 35 lumbar (MVA 57.1%, PS 20%, fall 25.7%), and 16 sacral/coccygeal (MVA 68.8%, PS 25%, fall 12.5%). Twenty-eight patients underwent spinal fusion (2-3 levels: 35.7%, 4-8 levels: 25.0%, >9 levels: 14.0%) and 14 had vertebral fracture repairs. After propensity-score matching (AIS: 432, Gen: 432), AIS patients had significantly more vertebral fractures (99 vs 52, p<0.001) and exhibited higher rates of thoracic (5.3% vs 2.5%, p=0.035) and lumbar fractures (8.1% vs 2.8%, p<0.001). Logistic regression showed AIS patients had increased odds of overall fracture (OR: 2.1 95% CI [1.4 - 3.1], p<.001), thoracic (OR: 2.2 95% CI [1.0 - 4.5], p=0.039) and lumbar fractures (OR: 3.1 95% CI [1.6 - 6.1], p<0.001).
CONCLUSION(S): AIS trauma patients relative to a normative trauma population were more likely to present with a vertebral fracture; specifically, thoracic and lumbar fractures. Authors acknowledge the limitations of the KID database, such as unavailability of radiographic data. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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