Faculty Bibliography

BACKGROUND CONTEXT: The ACS-NSQIP and SpineSage are both easy to use and readily available online perioperative risk calculators The ACS-NSQIP calculator predicts perioperative complications after surgery, but lacks more spine-specific predictors. The SpineSage platform was developed as a tool built for predicting complications in spine surgery. While a limited number of studies have shown it be predictive of both overall and major medical complications in spine surgery, large external validation studies are limited and none have directly compared NSQIP against SpineSage in the same cohort of spine surgery patients. PURPOSE: Assess the ACS-NSQIP Risk Calculator and SpineSage informatics platform for prediction of perioperative complications in spine surgery STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 440 patients undergoing thoracolumbar spine with or without fusion. OUTCOME MEASURES: Any complication, serious complication, pneumonia, cardiac, dural tear, SSI, UTI, VTE, reoperation, death and LOS METHODS: Each patient was entered into the ACS-NSQIP and SpineSage calculators and predicted risk for specific complications were directly compared to actual risks. Paired t-tests compared the differences between calculators and their predictability of complications. Patients were ranked based on risk predicted for each complication and the highest tertile for each was isolated. Multivariate regression controlling for age and gender was used to determine if the highest tertile for each risk calculator had predictability in complications following spine surgery.
RESULT(S): Mean LOS 4.2+3 days, EBL 444+300 mL, operative time 256+240 min, and levels instrumented 2.1+2.3. When assessing the four complications predicted by SpineSage there were significant differences in three of the four variables, as SpineSage underpredicted the risk of all and serious-complications (p.5). Both calculator tertiles were trending towards significance for major medical complications (SpineSage: OR: 2.0, [0.94-4.23], p=.073; ACS-NSQIP: OR: 1.8,[0.96-3.48],p=.067). When examining any medical risk, only ACS NSQIP had significant predictability for any medical complication (OR: 2.1, [1.3-3.3]; p=.003).
CONCLUSION(S): Similar to previous studies, the ACS-NSQIP score underpredicted most complications, with the exception of LOS and death. In contrast to previous studies, our data suggest SpineSage was not predictive of actual rates of complications. As both calculators are highly accessible and provide at least some objective perioperative risk data points, we recommend them as a guiding tool but not as an absolute endpoint for clinical decision making as they may be inaccurate and insensitive. Further, higher powered studies elucidating the findings in this study should be conducted. Additionally, the assessment of these calculators for a specific subset of patients, such as deformity, degenerative or pediatrics, can further help guide clinicians regarding the utility of these calculators for their particular patient populations. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Patients with coronal malalignment with trunk shift toward the convexity of the main coronal curve, and oblique takeoff at the lumbosacral junction, present a unique problem for deformity correction. PURPOSE: To evaluate fractional curve and coronal malalignment correction, and rate of complications and unplanned revision in Bao Type C patients, compared to Bao Type A and B patients. STUDY DESIGN/SETTING: Retrospective review of prospectively collected singlecenter database. PATIENT SAMPLE: This study included 1039 ASD patients (age: 46 +/- 23 y; mFI:.4 +/-.7; levels fused: 10.0 +/- 4.2). OUTCOME MEASURES: Outcomes evaluated were coronal alignment and fractional curve correction, and rates of revision surgery at two-year follow-up.
METHOD(S): A total of 1039 adult spinal deformity patients (age: 46 +/- 23 y; mFI:.4 +/-.7; levels fused: 10.0 +/- 4.2), with minimum five levels fused for thoracolumbar scoliosis were divided into three groups, as proposed by Bao et al: type A: CSVL 3cm and C7 plumb shifted to scoliosis' concavity (n=126); type C: CSVL > 3cm and C7 plumb shifted to scoliosis' convexity (n=30). Outcomes evaluated were coronal alignment and fractional curve correction, and rates of revision surgery at two-year follow-up.
RESULT(S): Type C patients more often had fractional curves, and the preoperative magnitude was significantly greater (15.7degree Type C, 12.9degree Type B, 9.6degree Type A, p <0.0001). Of the Type C patients, 50% had pedicle subtraction osteotomy performed, compared with 13.4% Type B, and 13.4% Type A (p <0.0001). Postoperatively, Type C patients continued to have persistently greater fractional curves (7.4degree Type C, 6.7degree Type B, 5.6degree Type A, p=0.026), and worse coronal malalignment (37.8 mm Type C, 34.1 mm Type B, 17.0 mm type A, p<0.0001), though equivalent results with regards to improvement in sagittal alignment, lumbar lordosis, pelvic tilt, and Cobb angle of the major curve. There rate of neurologic complications was higher in the Type C patients, specifically related to TLIF or PSO procedure performed. ALIF procedure in the Type C patients did not confer significant improvement in fractional curve correction, coronal or sagittal alignment correction, or greater lumbar lordosis, compared with TLIF procedure in these patients. There was no difference in the rate of 90-day unplanned readmission or reoperation between the groups. There was no difference in rates of rod fracture or pseudarthrosis at the interbody or PSO site in Type C patients, compared with Type A and B patients. There was no difference in rates or rod fracture, pseudarthrosis, adjacent segment disease, proximal junctional kyphosis, or reoperation for recurrent or persistent malalignment between the two groups at two-year follow-up.
CONCLUSION(S): At two-year follow-up, Type C coronal malalignment patients continue to have worse coronal deformity and fractional curve magnitude compared with Type A and B patients, with no difference, however, in long-term rod fracture, pseudarthrosis or revision surgery rates. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Indirect decompression technique may be limited in that it does not include direct removal of the offending intervertebral disc or osteophyte protruding into the canal. PURPOSE: This study evaluates resolution of radiculopathy and perioperative complications in lumbar fusion with indirect or direct decompression techniques. STUDY DESIGN/SETTING: Retrospective analysis of large single center academic institution. PATIENT SAMPLE: This study included 116 single-level lumbar fusion patients with preoperative radiculopathy from 2012 to 2021. OUTCOME MEASURES: Resolution of radiculopathy, visual analog scores (VAS), perioperative complications, motor scores.
METHOD(S): Patients 18 years of age diagnosed with preoperative radiculopathy undergoing single-level lumbar fusion with up to two-year follow-up were grouped by indirect and direct decompression. Direct decompression group included TLIF with or without direct decompression procedure as well as ALIF and LLIF with direct decompression procedure. Indirect decompression group included ALIF and LLIF without direct decompression procedure. Propensity score matching (PSM) was used to control for differences in age between groups. Outcome measures were compared between groups using means comparison tests. Logistic regression analysis was used to correlate decompression type with symptom resolution over time.
RESULT(S): A total of 116 patients were included in this analysis: 58 direct decompression (mean 53.9y, 67.2% female) and 58 indirect decompression (mean 54.6y, 61.4% female). Direct decompression patients experienced greater blood loss relative to indirect decompression patients (242.4 +/- 128.5 vs 171.79 +/- 143.9 mL, p=0.007). Additionally, direct decompressionpatients experienced full resolution of radiculopathy at 3 months postop at a greater rate than those in the indirect decompression group (OR: 4.742, [1.97-11.41]; 53.1% vs 13.73%, p=0.002). At 6 months, direct decompression patients demonstrated a significantly larger reduction in VAS score 6 months postop (-2.889 +/- 2.3 vs -0.897 +/- 4.3, p=0.044). With regard to motor function, direct decompression patients had improved motor score with respect to the L5 dermatome at 6 months compared to indirect decompression patients (DELTAmotor score from baseline: 0.1714 +/- 0.453 vs -0.024 +/- 0.154, p=0.019).
CONCLUSION(S): Patients who underwent direct decompression experienced significantly greater resolution of preoperative lower extremity radiculopathy at 3 months compared with those who underwent ID alone. At 6 and 12 months, no differences were noted between the two groups. There were no differences in complication rates. At 6 months postop, direct decompression patients had greater improvement in preoperative motor deficit than ID patients. In particularly debilitated patients, these findings may influence surgeons to perform a direct decompression to achieve more rapid resolution of radiculopathy symptoms. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Reducing fluoroscopy time and radiation exposure in the operating room is beneficial for the patient and surgical team. Placement of an interbody device during lateral transpsoas approach is traditionally carried out using anterior-posterior and lateral fluoroscopy. In this setting, 3-dimensional computed tomography (CT)-based spinal navigation of cage and pedicle screw/rod placement for LLIF procedure may result in decreased radiation exposure compared with fluoroscopically-guided LLIF. We sought to present our experience with the use of CT-based spinal navigation for the LLIF procedure and evaluate rates of intraoperative complications and radiation exposure. PURPOSE: To determine if computer-navigation guided LLIF will have equivalent outcomes with decreased radiation dose compared to fluoroscopy-guided LLIF. STUDY DESIGN/SETTING: Single-center retrospective review. PATIENT SAMPLE: This study included 250 patients over 18 years of age who underwent LLIF with <4 levels fused (age: 61.4 +/- 10.8 yrs, BMI: 29.7 +/- 6.1 7 kg/m2). OUTCOME MEASURES: Intraoperative and 90-day complications, radiation exposure and cage placement.
METHOD(S): Patients were separated into two groups: fluoroscopy-guided LLIF (n=224), and navigated LLIF (n=26). Cage placement was assessed on postoperative radiographs by dividing the disc space into quarters, anterior to posterior.
RESULT(S): In terms of operative characteristics, fluoroscopy dosage was significantly greater in the fluoroscopically-guided LLIF cohort (55.1 +/- 57.4 mGy vs 34.0 +/- 24.9 mGy, p=0.002). There were no significant differences between fluoroscopically-guided LLIFs and navigated LLIFs in overall intraoperative complication rate (4% Fluoro vs 0% Nav, p=0.3), rate of durotomy (2.2 % Fluoro vs 0% Nav, p=0.44), or estimated blood loss (322 +/- 330.3 cc Flouro vs 299.5 +/- 198.6 cc Nav, p=0.6). The rate of postoperative complications (26.8% Fluoro vs 26.9% Nav), neurologic complications (5.4% Fluoro vs 3.8% Nav), surgical site infections (1.3% Fluoro vs 3.8% Nav), mechanical complications (1.8% Fluoro vs 0% Nav) was not significantly different. There was no significant difference in the rate of unplanned return to the operating room within 90 days (1.8% Fluoro vs 0% Nav). Cage placement was similar between the two groups (p=0.29).
CONCLUSION(S): We report an average radiation exposure with navigated LLIFs of 34.0 mGy, significantly lower than the 55.1 mGy in the fluoroscopically-guided LLIF group. The length of stay and perioperative complication rate was equivalent between the groups. These data support the use of CT-based navigation for placement of the cage and pedicle screws/rod construct for LLIF procedure. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: The fractional curve is the curve below the major curve of a lumbar or thoracolumbar scoliosis, and while it is often the primary driver of the adult spinal deformity patient's decision to proceed with surgery, a treatment strategy to identify and address the fractional curve is not widely examined. There is a paucity of data evaluating the ideal strategy to correct the lumbosacral fractional curve in ASD surgery. PURPOSE: We sought to evaluate the impact of interbody fusion at L4-L5 and/or L5-S1 compared with posterior fusion alone on fractional curve correction, and rate of instrumentation related complications at the lumbosacral junction. STUDY DESIGN/SETTING: Retrospective review of prospectively collected single center database. PATIENT SAMPLE: A total of 592 ASD patients (Age: 48 +/- 23 y; mFI:.4 +/-.7; Levels fused: 10.3 +/- 4.1). OUTCOME MEASURES: Outcomes evaluated were fractional curve correction, overall deformity correction and rates of revision surgery for pseudarthrosis or rod fracture at the lumbosacral junction.
METHOD(S): A total of 592 ASD patients (Age: 48 +/- 23 y; mFI:.4 +/-.7; Levels fused: 10.3 +/- 4.1), lumbosacral fractional curve > 10degree, mean followup 39.5 months, were divided into 2 groups: PSF alone (PSF, n=382) and interbody fusion (IBF, n=210; ALIF: 31, TLIF: 179). Outcomes evaluated were fractional curve correction, overall deformity correction and rates of revision surgery for pseudarthrosis or rod fracture at the lumbosacral junction.
RESULT(S): A significantly greater number of patients in the IB cohort had underlying osteoporosis (63% versus 33%, p < 0.001); otherwise, there were no significant difference in patient comorbidities. There was significantly greater EBL (2.3 L vs. 1.3 L, p < 0.0001), intraoperative pRBCs transfused (2.3 U vs. 1.3 U, p < 0.001), and longer operative time (7.1 vs. 6.3 hours, p < 0.0001) in the IBF group compared with PSF. Both groups had similar magnitude of fractional curve correction (7.0 +/-7.1degree in IB vs. 6.3 +/- 6.9degree in PSF, p=0.26) and final coronal alignment (23.5 mm vs. 19.8 mm, p=0.08). Patients in the IBF group had a higher magnitude of SVA change (-30.6 mm vs -19.5 mm, p < 0.05) and increase in lumbar lordosis (11.5degree vs 5.6degree, p < 0.001). There was no difference in the rate of revision surgery at minimum 2-year followup for rod fracture, pseudarthrosis, or any instrumentation related complication. Sub-analysis demonstrated that there were no significant differences in magnitude of fractional curve correction, or improvement in lumbar lordosis, coronal, or sagittal alignment in the ALIF group compared to the TLIF group. There was no significant impact of number of levels at which a lumbar interbody fusion was performed on the degree of fractional curve correction.
CONCLUSION(S): At minimum 2-year followup, patients had comparable fractional curve and coronal alignment correction when treated with interbody fusion at L4-S1 versus posterior fusion alone. There was no difference in rod fracture and pseudarthrosis rates at 2-year followup. These data suggest that utilization of interbody technique at the lumbosacral junction is not clearly superior to posterior fusion alone for treatment of the fractional curve. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: VBT takes advantage of the Hueter-Volkmann principle, and modulates growth across intervertebral disc spaces with a tensioned tether secured at the lateral aspects of vertebral bodies. Cervical deformity in AIS patients is associated with lower health related quality of life. PSF constructs have been shown to improve cervical deformity, however, to date, these relationships have not been described in patients treated with VBT. PURPOSE: Determine if cervical sagittal alignment parameters following VBT for correction of AIS are similar to what is observed following PSF. STUDY DESIGN/SETTING: Multi-center retrospective cohort study. PATIENT SAMPLE: Patients with AIS that undergo correction surgeries with LIV in the lumbar spine from 2013 to 2021 with pre- and 2-year postop standing full body plain films available. OUTCOME MEASURES: Outcome measures: Age, height, weight, BMI, Risser score, LIV and levels instrumented. Radiographic analysis included pre- and postop C2 to C7 sagittal vertical axis (cSVA), cervical lordosis angle (CL), T1 slope and thoracic kyphosis (TK).
METHOD(S): Measures were compared using independent samples t-tests, significance set at p<0.05.
RESULT(S): A total of 99 patients: 49 VBT and 50 fusions. The VBT cohort Lenke class breakdown is 23% 1A, 13% 1C, 31% 3C; 18% 5C, and 15% 6C, while the PSF cohort consisted of 42% 1A, 6% 1B, 2% 2C, 2% 3B, 12% 3C, 2% 5B, 24% 5C, and 10% 6C. There were no significant differences with regard to patient age or number of levels instrumented. Patients included in the VBT cohort had a lower level of bone maturity as defined by Risser class (1.6+/-0.9 vs 2.6+/-1.8, p=0.001). The VBT cohort had higher baseline cSVA (3.4mm+/-1.6 vs -1.0mm+/-3.1, 0.001) and less CL (-0.6degree+/-18.2 vs 11.6degree+/-12.8, p=0.001) than the fusion cohort. No differences in baseline T1 slope or Thoracic Kyphosis was observed. VBT patients also had higher 2-year cSVA (3.4mm+/-1.4 vs -3.7mm+/-2.1, p=0.001) and less CL (-4.0+/-18.5 vs 7.0+/-12.2, p=0.001) compared to fusion patients. The PSF group had a significantly greater correction in cSVA than the VBT group (2.8mm+/-4.0 vs 0mm+/-1.6, p=0.001). Both groups displayed improvement in radiographic parameters of cervical and thoracic alignment including CL (VBT 3.3degreevs 4.3degree, p=0.74), T1 slope (VBT -4.3degreevs -4.9degree, p=0.81) and TK (VBT -6.1degreevs -3.9degree, p=0.47). After PSM for Lenke classification, 66 patients remained: 33 VBT, 33 PSF. The PSF group continued to demonstrate greater improvement in cSVA than the VBT group (3.2mm+/-3.0 vs -0.3+/-1.8, p=0.001.
CONCLUSION(S): VBT and PSF both improve radiographic parameters of cervical alignment in AIS patients; however, PSF showed greater correction of cSVA at 2-year followup. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: L5 nerve root palsy is a complication that can occur after ALIF indirect decompression. It is thought to occur due to the dimensional change in the L5 foramen that can either compress or cause a stretch neuropraxia of the nerve root. While this complication has been observed, reports and studies highlighting its incidence and risk are lacking. PURPOSE: To determine whether ALIF leads to an increased risk in L5 palsy, we sought to compare the relative risk compared to TLIF. We hypothesize that since foraminotomy is part of the TLIF procedure, it should demonstrate a difference in nerve root palsy compared to ALIF indirect decompression. STUDY DESIGN/SETTING: A single institution retrospective cohort study. PATIENT SAMPLE: A total of 626 patients (262 ALIF, 179 open TLIF, 185 MIS TLIF). The study period was 2017 to 2021. OUTCOME MEASURES: Primary outcomes were postoperative leg pain, sensory deficits, and motor weakness in tibialis anterior (TA), extensor hallucis longus (EHL) and gastrocnemius (GC). Secondary outcomes were infection, return to operating room (OR), and return to emergency center (EC) within 90 days.
METHOD(S): Retrospective comparative cohort study comparing ALIF vs TLIF. Inclusion criteria were all patients who underwent L5-S1 ALIF or L5-S1 TLIF (both open and MIS). Multilevel surgeries were excluded. The rate of postop nerve palsy was compared for the two treatment approaches. Chi-square was performed for all categorical comparisons and ANOVA was performed for continuous statistical comparisons.
RESULT(S): There were subtle differences in baseline characteristics between groups. ALIF patients were younger (p = 0.016), had less BMI (p = 0.026) and less likely to smoke (p = 0.008). There were no differences in gender or diabetes status. Patients undergoing TLIF (open and MIS) were more likely to be operated for lumbar spinal stenosis and radiculopathy (p < 0.001). There was an overall 3% rate of neuro deficits in the study population with a higher rate in those undergoing ALIF (5.3%) compared with open TLIF (0.6%) and MIS TLIF (2.2%) (p = 0.011). There was a rate of 3.1% EHL palsy in the ALIF group which was higher than TLIF (both open and MIS) (p = 0.048). There was a trend towards higher TA and GC nerve deficits in the ALIF group, but the difference was not significant. Additionally, there was a trend towards higher rates of return to OR for nerve deficit in the ALIF group, but this was not significant. However, ALIF patients had higher return to OR in 90 days for any reason (p = 0.01). There were no further differences between the groups. Among the 14 ALIF patients with any nerve deficit, 7 followed up at 3 mos and 5 in 1 year. At 3 mos, 5 of 7 patients had improvement in their nerve deficit and at 1 year, 5 of 5 patients had improved their deficiency.
CONCLUSION(S): This study demonstrates a higher rate of L5 nerve root palsy with ALIF compared to TLIF as evidenced by higher rates of EHL palsy with a rate of 3.1% in our study population. The study, however, is limited by its retrospective nature and subtle differences noted in demographics. Despite these differences, ALIF patient characteristics tended to be more favorable, which are unlikely to confound results of higher postoperative nerve deficits. Further study will be required to understand the mechanisms and radiological risk factors for postoperative L5 palsy after ALIF. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: In recent years spine surgeons have utilized different techniques and approaches to perform lumbar interbody fusion surgery. We sought to analyze the difference in outcomes between traditional open transforaminal lumbar interbody fusion (O-TLIF), minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), dual position anterior/lateral lumbar interbody fusion with posterior instrumentation (Dual ALIF/LLIF), and single position anterior/lateral lumbar interbody fusion with posterior instrumentation (Single ALIF/LLIF). PURPOSE: To analyze the perioperative and postoperative outcomes of patient undergoing TLIF, MIS TLIF, Dual ALIF/LLIF, and Single ALIF/LLIF. STUDY DESIGN/SETTING: Retrospective cohort study at a single institution. PATIENT SAMPLE: Patients undergoing O-TLIF, MIS TLIF, Dual ALIF/LLIF, or Single ALIF/LLIF from 2014 to 2020. OUTCOME MEASURES: Operative time, estimated blood loss (EBL), length of stay (LOS), radiation dose, intraoperative and postoperative complications, and return to OR within 90 days.
METHOD(S): Patients who underwent single level lumbar interbody fusion surgery were analyzed. Patient charts were reviewed for operative time, EBL, LOS, radiation dose, intraoperative and postoperative complications, and return to OR within 90 days. Differences were assessed by ANOVA.
RESULT(S): A total of 1,226 patients underwent a single level lumbar interbody fusion (440 O-TLIF, 423 MIS TLIF, 316 Dual ALIF/LLIF, 47 Single ALIF/LLIF). There were no significant differences in BMI or gender between the groups, but in the O-TLIF cohort average age (60) was higher than MIS-TLIF (54), Dual ALIF/LLIF(52), and Single ALIF/LLIF (50) p < 0.001. There were also significant differences in average operative time (221 mins O-TLIF, 212 mins MIS TLIF, 277 mins dual ALIF/LLIF, 277 mins single ALIF/LLIF, p < 0.001), EBL (360 ml O-TLIF, 167ml MIS TLIF, 235 ml Dual ALIF/LLIF, 253 ml Single ALIF/LLIF, p<0.001), radiation dose (20 mGy O-TLIF, 51 mGy MIS TLIF, 43 mGy Dual ALIF/LLIF, 62 mGy Single ALIF/LLIF, p < 0.001). There was no difference in LOS, intraoperative complications, or 90-day complications between the groups, except a higher rate of neurological deficit in dual ALIF/LLIF (1.6%, p < 0.03). Post hoc analysis demonstrated statistical significance in operative time in the Dual ALIF/LLIF as compared to all the other groups. O-TLIF demonstrated a larger EBL and less radiation as compared to all the other groups as well as a longer operative time than Single ALIF/LLIF. Dual ALIF/LLIF demonstrated a longer operative time and increased rate of neurological deficit as compared to MIS TLIF.
CONCLUSION(S): In comparing different techniques for single level lumbar interbody fusion there were similar outcomes in LOS, perioperative complications and 90-day complications between all the groups. Open TLIF was associated with increased estimate blood loss and less radiation than all the other groups Dual position ALIF/LLIF surgery was associated with a longer operative time than all the other groups. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: It has been shown that smoking is associated with delayed fusion and pseudarthrosis after spine surgery. The impact of smoking on both short- and long-term outcomes in patients undergoing spine surgery has been described. There are limited data on the impact of smoking status on outcomes after adult spinal deformity (ASD) surgery. We sought to analyze a large cohort of in a single center, to add more to our understanding of the effect of smoking both on mortality and postoperative complications. PURPOSE: To evaluate the effect of smoking on 90-day complications after ASD surgery as well as pseudarthrosis and unplanned revision at long term follow up. STUDY DESIGN/SETTING: Retrospective review of prospectively collected database. PATIENT SAMPLE: A total of 1,013 ASD patients (Age: 46 +/-23 years; mFI: 0.44 +/- 0.70; levels fused: 10.1 +/- 4.2). OUTCOME MEASURES: Outcome measures studied included perioperative complications, and long-term revision surgery rates.
METHOD(S): A total of 1,013 ASD patients (Age: 46 +/-23 ye ars; mFI: 0.44 +/- 0.70; levels fused: 10.1 +/- 4.2) were stratified based on smoking status into three groups. Current smokers group (n = 72) included all patients who were active smokers and those who quit smoking within 4 weeks of surgery. Former smokers group (n = 265) included all patients who quit smoking more than 4 weeks before surgery. Nonsmokers (n = 676) included all patients who had never smoked in their lives before surgery. Outcome measures studied included perioperative complications and long-term revision surgery rates.
RESULT(S): With regards to early complications, the readmission rate at 90 days was significantly higher in the current (12.7%) and former smokers (12.0%), compared with nonsmokers (6.1%) (p=0.007). There was a significantly higher rate of postoperative epidural hematoma in smokers (5%), compared to former and nonsmokers (0%) (p<0.001). There was a higher rate of postoperative pneumonia in smokers (4.5%) compared to former smokers (1.4%) and nonsmokers (0.07%) (p=0.038). There was no significant difference in length of stay between the groups. At minimum one-year follow up, there was a significantly higher rate of pseudarthrosis (smokers: 15.6%, former: 6.7%, non: 4.5%, p=0.041) with no significant difference in rate of revision surgery for pseudarthrosis. Smokers had a significantly higher rate of neurologic complications (29% vs 18.5%, p=0.001) compared to nonsmokers. Smokers who did not experience any resolution of the neurologic injury had greater pack year history (28.5 +/-22) versus smokers who experienced complete resolution (21.2 +/- 39.3) (p=0.02).
CONCLUSION(S): Smoking is associated with higher 90-day readmission rate, and higher rates of epidural hematoma, neurologic complication and postoperative pneumonia after ASD surgery. At one year, smokers have a higher rate of pseudarthrosis, and those with greater pack year history were less likely to experience resolution of the neurologic injury sustained at the index surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Sagittal alignment is integral to a patient's quality of life. Posterior spinal fusion (PSF) is currently the standard for correcting adolescent idiopathic scoliosis (AIS). Vertebral body tethering (VBT) is a fusionless growth modulating surgical technique used to treat AIS. It relies on the Hueter-Volkmann Law. Indications for this procedure include patients who have coronal curves up to 50degree, growth remaining, and no excessive thoracic kyphosis. VBT has been shown to have good coronal plane deformity correction. There have been fewer examinations of the sagittal effects of VBT. PURPOSE: To determine if VBT is a non-inferior treatment for correction of AIS with regard to sagittal alignment compared to PSF. STUDY DESIGN/SETTING: Multicenter retrospective cohort study. PATIENT SAMPLE: Patients with AIS who underwent correction surgeries with LIV in the lumbar spine from 2013 to 2021 with pre- and minimum two-year postoperative standing full spine plain films. OUTCOME MEASURES: Sagittal vertical axis (SVA), cervical SVA (cSVA), pelvic tilt (PT), thoracic kyphosis (TK), cervical lordosis (CL), L4-S1 lordosis (L4L), T1 pelvic angle (TPA) and pelvic incidence lumbar lordosis mismatch (PI-LL).
METHOD(S): Radiographic analyses was completed with independent samples t-test with significance set to p <0.05.
RESULT(S): A total of 99 patients were included, 49 VBT and 50 PSF. There were no differences in age or levels instrumented between groups. The VBT cohort Lenke class breakdown is 23% 1A, 13% 1C, 31% 3C. 18% 5C, and 15% 6C, while the PSF cohort consisted of 42% 1A, 6% 1B, 2% 2C, 2% 3B, 12% 3C, 2% 5B, 24% 5C, and 10% 6C. At Baseline, the VBT cohort had lower SVA (-0.7mm+/-3.7 vs 2.2mm+/-5.0, p=0.001), CL (-0.9degree+/-18.2 vs 11.6degree+/-12.8, p=0.001), L4-S1 Lordosis (20.7degree+/-16.0 vs 41.6degree+/-10.2, p=0.001), and higher cSVA (3.3mm+/-1.6 vs -0.95mm+/-3.1, p=0.001) than those who were fused. Postoperatively, VBT patients have an overall higher L4-S1 Lordosis (36.0degree+/-10.1vs 18.3degree+/-12.5, p=0.001), cSVA (3.4mm+/-1.4 vs -3.7mm+/-2.1, p=0.001), and lower CL (-4.3degree+/-18.4 vs 7.0degree+/-12.2, p=0.001). The PSF cohort had a larger change in cSVA (2.8mm+/-4.0 vs 0mm+/-1.6, p=0.001) from baseline to 2-year follow-up compared to VBT. No differences in the change of L4-S1 Lordosis (VBT 1.5degree+/-12.3 vs 4.1degree+/-10.9, p=0.3), TPA (VBT -1.6degree+/-6.8 vs -1.4degree+/-8.5, p=0.89), PT (VBT -0.5degree+/-7.8 vs -1.9degree+/-8.5, p=0.42), or PI-LL (0.2degree+/-12.0 vs -0.5degree+/-14.0, p=0.81) were observed.
CONCLUSION(S): VBT and PSF for AIS result in statistically similar changes in sagittal alignment parameters. The fact that we showed similar results comparing sagittal alignment in fusion and VBT groups indicates that VBT is non-inferior from a sagittal perspective. It is important to maintain sagittal alignment when correcting AIS. Future work can examine the long-term effect of VBT on sagittal alignment. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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