Faculty Bibliography

BACKGROUND CONTEXT: Preoperative risk stratification is critical to determining which adult spinal deformity (ASD) patients may develop postop complications and to maximize surgical success. Currently it is unknown if a preoperative inflammatory state results in a higher risk for postop complications. This information can be used in risk stratification models to aid in complication avoidance. PURPOSE: To determine if patients with preoperative elevated serum markers for inflammation have higher rates of postoperative complications STUDY DESIGN/SETTING: Retrospective review of multicenter prospective ASD database. PATIENT SAMPLE: ASD patients. OUTCOME MEASURES: C-reactive protein (CRP), Erythrocyte sedimentation rate (ESR), complications by type and by severity of intervention: none, mild, moderate and severe. Demographic and surgical variables: age, estimated blood loss (EBL), operating room (OR) time, body mass index (BMI), America Society of Anesthesia physical classification scale (ASA), Charlson comorbidity index (CCI), Edmonton frailty scale (EF), 3-column osteotomy (3CO), number of post fusion levels.
METHOD(S): Preoperative labs were drawn on ASD patients and the inflammatory markers were CRP and ESR. CRP thresholds for cardiac risk: normal = 3. The CRP moderate and elevated values were combined into one group named elevated. Normal ESR thresholds: Male age 50, =20, Female >50, =30. Patients were stratified by having normal or elevated markers and rates of complications were compared between the groups. A multivariate model with CRP/ESR and demographic/surgical variables for postoperative complications. Health-related quality of life (HRQOL) metrics were compared RESULTS: The total number of patients with preoperative CRP was 159 and ESR was 158. CRP: normal=114 patients (71.7%), moderate elevation=28 (17.6%), severe elevation=17 (10.7%). Combined elevated=45/159(28.3%). Elevated ESR=25(15.8%), normal=133(84.2%). The elevated CRP group had significantly higher rate of moderate complication 13/45(28.9%) vs 16/114(14.0%), p=0.03 and severe complication 15/45 (33.3%) vs 17/114(14.9%, p=0.009. Elevated ESR patients had significantly higher rate of moderate complication 9/25 (36.0%) vs 20/133 (15.0%), p=0.01. In multivariable logistic regression elevated CRP had odds ratio for moderate complication of 3.3 (95% CI 1.4-7.6, p=0.006), and for severe complication of 2.3 (95% CI 1.05-5.1, p=0.037). Multivariable logistic regression for elevated ESR and moderate complication had odds ratio of 2.9 (95%CI 1.04-7.8, p=0.041). Elevated CRP also had significantly higher rate of wound complications (15.6% vs 3.5%, p=0.007) and MSK complications (11.1% vs 1.8%, p=0.01). Elevated ESR had significantly higher rate of cardiac complications (32.0% vs 13.5%, p=0.02) and neurological complications (24.0% vs 9.0%, p=0.03). Elevated CRP had worse preoperative leg pain, SRS Activity and VR12 PCS(p<0.05). Elevated ESR had worse baseline ODI (p=0.03).
CONCLUSION(S): A preoperative inflammatory state as defined by elevated CRP and ESR is an independent risk factor for the development of moderate and severe postop complications. Having elevated preop CRP is 3.3 and 2.3 times more likely to have a moderate and severe complication, respectively. Elevated ESR is 2.9 times more likely to have a moderate complication. This data can be used in risk stratification models to aid in minimizing postoperative complications. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Previous reports indicate postoperative complications have minimal impact on long-term outcomes after ASD surgery. Little data has evaluated the impact of complications on specific heath domains during postoperative period. PURPOSE: To evaluate the impact of specific complications on patient reported health domains compared to patients with no complications. STUDY DESIGN/SETTING: Prospective, multicenter, propensity score matched analysis. PATIENT SAMPLE: ASD patients enrolled into a prospective multi-center study. OUTCOME MEASURES: Oswestry Disability Index, Scoliosis Research Society-22r questionnaire (SRS-22r), Short Form-36v2 questionnaire (SF-36), postoperative complications.
METHOD(S): Surgically treated ASD patients enrolled into a multicenter study were assessed for postoperative complications requiring surgery including wound (WOUND), pseudoarthrosis (PSEUDO), neurologic (NEURO) and malalignment (MAL) and matched to patients with no complications (NOCOMP) using inverse probability weighting for demographic, radiographic and surgical variables. Health domains for SRS-22r, and SF-36 were evaluated at regular time intervals, domain scores normalized to the date of revision surgery, and compared to patients with no complications at minimum 2-year follow-up.
RESULT(S): A total of 566 of 1130 were analyzed, average 3.6 yrs (range: 1.9 to 9). WOUND (n=12) compared to NOCOMP (n=390) had worse SF-36 physical function(21.7 vs 27.4), social function(19.6 vs 28.9), general health (-7.3 vs 8.9) and vitality (-0.9 vs 26.6,p < 0.05). PSEUDO (n=64) was worse than NOCOMP for SRS-22r function, 1.4 vs 2.1, and SF-36 social function, (17.1 vs 28.9) (p < 0.05). NEURO (n=28) was worse than NOCOMP for SRS-22r (0.9 vs 2.1), SF-36 bodily pain (14.7 vs 35.7) and social function (13.4 vs 28.9) (p < 0.05). MAL (n=72) was worse than NOCOMP for SRS-22r pain, (2.7 vs 3.4), function (1.2 vs 2.1), self-image (3.0 vs 3.9), SF-36 bodily pain (27.6 vs 35.7), physical function (18.7 vs 27.4), and social function (11.6 vs 28.9) (p < 0.05).
CONCLUSION(S): Counter to previous reports, specific postoperative complications requiring surgery uniquely impact specific health domains, resulting in worse patient reported quality of life compared to ASD patients with no complications. Social function was negatively impacted for all complications, while wound complications negatively impacted patient perceived general health and vitality and patients with malalignment requiring surgery reported worse self-image. These data highlight new findings that postoperative complications have a negative impact on specific aspects of ASD quality of life that can undermine the potential benefits of ASD surgery. 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: Numerous studies have reported the interplay between spinal deformity and pelvis compensatory mechanisms, but little data exist evaluating the contribution of lower extremity compensation (LE) to maintain upright posture. We hypothesis that hip, knee and ankle compensation is proportional to the severity of the spinal deformity and varies by demographics. PURPOSE: Evaluate the association between spinal alignment and lower limbs compensation. STUDY DESIGN/SETTING: Multicenter, prospective cohort. PATIENT SAMPLE: This study included 288 patients treated for complex adult spinal deformity (ASD) with full body images available. OUTCOME MEASURES: Pelvic retroversion (PT), hip extension (SFA), knee flexion (KA), ankle dorsiflexion (AA), pelvic translation (P.Shift) and patient reported outcomes (ODI, PROMIS and SRS-22).
METHOD(S): Surgical ASD patients were enrolled into a prospective study based on three criteria: deformity severity (PI-LL>25degree, TPA>30degree, SVA>15cm, TCobb>70degree or TLCobb>50degree), procedure complexity (>12 levels fused, 3CO or ACR) and/or age (>65 and >7 levels fused). Associations between lower extremity compensation (hip extension, knee flexion, and ankle dorsiflexion) and the magnitude of spinal deformity, patient demographics, patient frailty, and patient-reported outcomes (ODI, SRS, PROMIS-CAT) were assessed via regressions and partial correlations.
RESULT(S): A total of 288/329 patients met inclusion criteria (60+/-15yo, 70.5% female), had moderate to severe spinal deformity (PI-LL:15+/-24, TPA:24+/-14, SVA:65+/-69mm, lumbar Cobb:34+/-24), and reported high pain (PROMIS pain interference; PI=62.7+/-7.8) and reduced physical function (PROMIS physical function; PF=35.6+/-7.6). Lower extremity compensation included pelvic retroversion (PT:24.1+/- 11.8), hip extension (SFA: 203+/-10.5), knee flexion (KA:5.5+/- 9.6), ankle dorsiflexion (AA: 5.3+/-4.5), and posterior pelvic translation (P.Shift: 30+/-51mm). Overall, lower extremity compensation increased with age (all p <0.001), BMI and frailty (all p <0.001, except SFA). For a similar PT, women had greater hip extension than men (SFA: 206 vs 200, p <0.001), with less KA (3.6 vs. 10.1, p <0.001), AA, and P.Shift. Lower extremity compensation increased with PI (r=0.2-0.45, p <0.001), TPA (r=0.5-0.9, p <0.001) and correlated with PROMS (ODI:0.26 - 0.37, PROMIS PF: -0.28 - -0.39, SRS Acti.: -0.20 - -0.33). When controlling for deformity severity and PI, most associations between lower limbs compensation and PROMS were lost. However, P.Shift and SFA remained weakly correlated with physical scores (ODI and PROMIS PF).
CONCLUSION(S): The recruitment of LE compensation is overall proportional to the severity of adult spinal deformity, with different patterns observed between men and women. Patients achieved similar PT by recruiting different patterns of LE compensation. Hip extension and posterior pelvic translation are independently associated with impairment in patient-reported outcomes. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Evidence on long-term surgical recovery in adult spinal deformity (ASD) patients who are both frail and have an invasive procedure is limited. PURPOSE: This study aims to evaluate frail and invasive patients with 5-year recovery kinetics. We hypothesize that patients who are both frail and have invasive surgeries will have adverse postoperative recovery kinetics STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: A total of 133 ASD patients with complete HRQOL data at preoperative, 1-year, 2-year, 5-year follow-up were included. OUTCOME MEASURES: Integrated Health State Scores (IHS) in Oswestry Disability Index (ODI), Short-form 36 (SF-36) physical (PCS) and mental (MCS) component score, and Scoliosis Research Society (SRS)-22r measures METHODS: ASD-FI scores were used to stratify non-frail (0.3) patients. ASD-SR scores were used to stratify low invasive (90) surgeries. Using ASD-FI and ASD-SR, patients were separated into four cohorts: non-frail low invasive (NFLI), frail low invasive (FLI), non-frail high invasive (NFHI), and frail high invasive (FHI). HRQOLs at 1 year, 2 years, and 5 years were normalized against preoperative values. AUC was calculated across time points to generate an integrated health state score (IHS). Multivariable linear regression was used to compare IHS scores of FLI, NFHI, and FHI to NFLI while controlling for age, gender, comorbidity, and radiographic alignment.
RESULT(S): Of 633 eligible ASD patients, 339 had 5-year follow-up. Of those, 125 patients with complete HRQOL data at preoperative, 1-year, 2-year, and 5-year visits were included; 27.2% (34) were NFLI, 20.0% (25) were FLI, 26.4% (33) were NFHI, and 26.4% (33) were FHI. Using NFLI as the referent, FLI and NFHI did not have differences in ODI, MCS, PCS or SRS-22r IHS scores (P >0.05). On multivariable analysis of integrated health scores, FHI had higher MCS (7.6 vs 5.47; P=0.0188), SRS activity (6.97 vs 5.67; P=0.0004), SRS pain (8.49 vs 6.4; P=0.001), SRS appearance (8.97 vs 6.81; P=0.0014), SRS satisfaction (11.71 vs 7.97; P=0.0033), and SRS total (7.49 vs. 6.09; P=0.0002), indicating more improved recovery over a 5-year period. Patients who were FHI had higher rates of complications (P <0.05).
CONCLUSION(S): Despite having more complications, patients who were frail and underwent more invasive surgeries were more likely to have greater overall improvement in activity, pain, and satisfaction over a 5-year period relative to preoperative baseline. Our results suggest that frailty in combination with invasiveness do not hinder long-term postoperative recovery kinetics, in comparison to frailty or invasiveness alone. 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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BACKGROUND CONTEXT: While past research has shown racial disparities exist in the outcomes and utilization of spine surgery, those studies were often performed on nondisease-specific national databases, which may capture different patient populations and complication rates compared to prospective multicenter databases. PURPOSE: Purpose: 1) Assess racial disparities for enrollment in two prospective multicenter databases (ASD-

BACKGROUND CONTEXT: Prior reports have focused on grading fusion status after adult spinal deformity (ASD) surgery; however, few focused on fusion status after 4-years postop. PURPOSE: To identify risk factors for nonunion in a prospective cohort of ASD patients with long-term follow-up (=4 years). STUDY DESIGN/SETTING: Prospective multicenter observational series. PATIENT SAMPLE: Database enrollment required age =18 years, scoliosis =20degree, sagittal vertical axis (SVA) =5cm, pelvic tilt =25degree, or thoracic kyphosis =60degree. OUTCOME MEASURES: Fusions were rated as bilaterally fused (A), unilaterally fused (B), partially fused (C), or not fused (D). Primary outcome was fusion (grade A or B) vs nonunion (grade C or D) at minimum 4-year follow-up. Secondary outcome measures included health-related quality of life (HRQL) (Oswestry Disability Index [ODI], Short Form-36 [SF-36] scores, Scoliosis Research Society-22 [SRS-22r] scores).
METHOD(S): Surgically treated ASD patients prospectively enrolled into a multicenter study (2008-2020) were assessed for fusion (grade A or B) vs nonunion (grade C or D). Inclusion required postop fusion grading at minimum 4-year follow-up. Demographics, frailty, comorbidities, alignment (baseline and initial correction), index surgery (total levels fused, iliac fixation, interbody fusion [IBF], use of bone morphogenetic protein [BMP] and/or demineralized bone matrix [

BACKGROUND CONTEXT: Adult spinal deformity (ASD) patients maintain upright posture by compensating through their spine, pelvis and lower extremities. Little data exist quantifying the contribution of lower extremity compensation through the hips, knees, and ankles to maintain upright posture. PURPOSE: Evaluate the effect of the lower limb compensation by numerically unfolding patients. STUDY DESIGN/SETTING: Multicenter, prospective cohort. PATIENT SAMPLE: A total of 288 patients surgically treated for complex ASD with preoperative full body images. OUTCOME MEASURES: Horizontal distance between vertebra centroid and ankle.
METHOD(S): Surgical ASD patients were enrolled into a prospective study based on three criteria deformity severity (PI-LL>25degree, TPA>30degree, SVA>15cm, TCobb>70degree or TLCobb>50degree), procedure complexity (>12 levels fused, 3CO or ACR) and/or age (>65 and >7 levels fused). Preop full-body images were evaluated and age and PI-adjusted normative values were used to model spine alignment based upon three configurations: COMP (all lower extremity compensatory mechanisms maintained), PARTIAL (removal of ankle dorsiflexion and knee flexion, maintained hip extension), UNCOMP (ankle, knee, and hip compensation eliminated by reset PT to the age and PI norms). The three configurations were compared, and COMP alignment was stratified by TPA percentiles to investigate the offsets from each vertebra to the ankle joint acting as a surrogate of the gravity line in free-standing position.
RESULT(S): A total of 288 patients met inclusion criteria (60+/-15yo, 70.5% female, 27.4+/-5.9 BMI). COMP spine deformity magnitude included PI-LL 15+/-24, TPA 24+/-14, and SVA 65+/-69mm. As the model transitioned from COMP to UNCOMP alignment, the initial posterior translation of the pelvis decreased significantly to an anterior translation vs the ankle (P.Shift 30 to -7.6 mm). This was associated with a decrease in pelvic retroversion (PT 24.1 to 16.1), hip extension (SFA 203 to 200), knee flexion (KA 5.5 to -0.4), and ankle dorsiflexion (AA 5.3 to 3.7). As a result, the anterior malalignment of the trunk significantly increased SVA (65 to 120mm) and G-SVA (C7-Ankle from 36 to 127 mm), leading to a three-fold increase in bending moments sustained by the ankle joint. The stratification of the COMP position by TPA percentiles revealed that as the deformity increases, the vertebrae above T8 translate anteriorly, those below T10 move posteriorly, with the T8-T10 segment remaining ~3cm posterior to the ankle joint independently of the deformity severity.
CONCLUSION(S): Removal of lower limbs' compensation revealed an unsustainable truncal malalignment with a three-fold increase of bending moments at the ankle joints. Combined, lower limb compensations permit "reducing" the SVA by two-fold and the C7-ankle SVA by three-fold. From a mechanical point of view, this compensation permits maintaining the trunk center of mass (T9) at a fixed offset of ~3 cm from the ankle joint. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Previous literature has demonstrated the advantages of lateral single position surgery (L-SPS) in the perioperative period; however, 2-year postoperative outcomes of this novel technique have not yet been compared to circumferential anterior-posterior fusion (FLIP) at 2-years postoperatively. PURPOSE: Evaluate the feasibility and safety of L-SPS technique against the conventional FLIP. STUDY DESIGN/SETTING: Multi-center retrospective cohort study. PATIENT SAMPLE: Patients undergoing primary AP (ALIF or LLIF) fusions with bilateral percutaneous pedicle screw fixation between L2-S1 with minimum 2-year followup at three institutions. OUTCOME MEASURES: Outcome measures included levels fused, operative time, estimated blood loss and perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI-LL mismatch and segmental lumbar lordosis.
METHOD(S): Patients were grouped as L-SPS if anterior and posterior portions of the procedure were performed in the lateral decubitus position, and FLIP if patients were repositioned from supine or lateral to prone position for the posterior portion of the procedure. Groups were compared in terms of demographics, intraoperative, perioperative and radiological outcomes, complications and reoperations up to 2 years follow-up. Measures were compared using independent samples or paired t-tests and chi-squared analyses with significance set at p<0.05.
RESULT(S): A total of 442 pts met inclusion, including 352 L-SPS and 90 FLIP pts. Significant differences were noted in age (62.4 vs. 56.9; p= < 0.001) and smoking status (7% vs. 16%; p=0.023) between the L-SPS and FLIP groups. No differences between L-SPS and FLIP were noted in gender (57.4% female vs 57.8% female, p=1.000), BMI (30.0kg/m2 vs 29.3kg/m2; p=0.318). No differences were noted in number of levels fused between L-SPS and FLIP (1.45vs 1.50; p=0.533), proportion including ALIF (38% vs 39%; p=0.809), or the proportion of surgeries including L5-S1 (38%vs 31%; p=0.222). Perioperative outcomes: L-SPS demonstrated significantly lower Op time (97.7min vs 297.0 min; p < 0.001), fluoro dose (36.5mGy vs 78.8mGy; p < 0.001), EBL (88.8mL vs 270.0mL; p < 0.001), and LOS (1.91 days vs. 3.61 days; p < 0.001) compared to FLIP. L-SPS also demonstrated significantly fewer post-op complications than FLIP (21.9% vs 34.4%; p=0.013), specifically regarding rates of ileus (0.0% vs 5.6%; p < 0.001). There was no difference in remaining surgical site, neurological, or medical complications between groups. Reoperation: N=no differences in reoperation were noted at 30-day (1.7%L-SPS vs 4.4%FLIP, p=0.125), 90-day (5.1%L-SPS vs 5.6%FLIP, p=0.795) or 2-year follow-up (9.7%L-SPS vs 12.2%FLIP; p=0.441). The most common reason for return to OR was Adjacent Segment Disease, (L-SPS 3.1% vs. FLIP 7.8%; p=0.067). Pseudarthrosis rates were similar between groups (0.0%L-SPS vs. 1.1%FLIP; p=0.204). Radiological Outcomes: no significant differences were noted in rates of radiological fusion (94.3% L-SPS vs 97.8%FLIP; p=0.266) or subsidence (6.9%L-SPS vs 12.2%FLIP; p=0.260). There were no differences noted between L-SPS and FLIP in change in LL from Baseline to 1-year (3.5 vs 2.8; p=0.466) and post-op to 1yr (-0.18 vs -0.51; p=0.777), or in PI-LL from Baseline to 1-year (-3.5 vs -3.2; p=0.835) and from post-op to 1-year (0.71 vs 0.71; 0.998).
CONCLUSION(S): L-SPS improves safety, improves operative efficiency and reduces complications in the perioperative period while maintaining similar efficacy of AP fusion at 2-year followup in treating degenerative lumbar spinal conditions. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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